| 1. |
- Edén, Arvid, 1975, et al.
(author)
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CSF biomarkers in patients with COVID-19 and neurological symptoms: A case series.
- 2021
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In: Neurology. - 1526-632X. ; 96:2
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Journal article (peer-reviewed)abstract
- To explore whether hospitalized patients with SARS-CoV-2 and neurologic symptoms have evidence of CNS infection, inflammation and injury using CSF biomarker measurements.We assessed CSF SARS-CoV-2 RNA along with CSF biomarkers of intrathecal inflammation (CSF white blood cell count, neopterin, β2-microglobulin (β2M) and immunoglobulin G-index), blood-brain-barrier (BBB) integrity (albumin ratio), and axonal injury (CSF neurofilament light chain protein [NfL]) in 6 patients with moderate to severe COVID-19 and neurologic symptoms who had undergone a diagnostic lumbar puncture. Neurologic symptoms and signs included features of encephalopathies (4/6), suspected meningitis (1/6) and dysgeusia (1/6). SARS-CoV-2 infection was confirmed by rtPCR analysis of nasopharyngeal swabs.SARS-CoV-2 RNA was detected in the plasma of 2 patients (Cycle threshold [Ct] value 35.0-37.0) and in CSF at low levels (Ct 37.2, 38.0, 39.0) in 3 patients in one but not in a second rtPCR assay. CSF neopterin (median, 43.0 nmol/L) and β2-microglobulin (median, 3.1 mg/L) were increased in all. Median IgG-index (0.39), albumin ratio (5.35) and CSF white blood cell count (<3 cells/µL) were normal in all, while CSF NfL was elevated in 2 patients.Our results on patients with COVID-19 and neurologic symptoms suggest an unusual pattern of marked CSF inflammation in which soluble markers were increased but white cell response and other immunologic features typical of CNS viral infections were absent. While our initial hypothesis centered on CNS SARS-CoV-2 invasion, we could not convincingly detect SARS-CoV-2 as the underlying driver of CNS inflammation. These features distinguish COVID-19 CSF from other viral CNS infections, and raise fundamental questions about the CNS pathobiology of SARS-CoV-2 infection.
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| 2. |
- Edén, Arvid, 1975, et al.
(author)
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Differential effects of efavirenz, lopinavir/r, and atazanavir/r on the initial viral decay rate in treatment naïve HIV-1-infected patients.
- 2010
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In: AIDS research and human retroviruses. - : Mary Ann Liebert Inc. - 1931-8405 .- 0889-2229. ; 26:5, s. 533-40
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Journal article (peer-reviewed)abstract
- Initial viral decay rate may be useful when comparing the relative potency of antiretroviral regimens. Two hundred twenty-seven ART-naïve patients were randomized to receive efavirenz (EFV) (n = 74), lopinavir/ritonavir (LPV/r) (n = 77), or atazanavir/ritonavir (ATV/r) (n = 79) in combination with two NRTIs. The most frequently used NRTI combinations in the EFV and ATV/r groups were the nonthymidine analogues tenofovir and emtricitabine or lamivudine (70% and 68%, respectively) and, in the LPV/r group, lamivudine and the thymidine analogue zidovudine (89%). HIV-1 RNA was monitored during the first 28 days after treatment initiation. Phase 1 and 2 decay rate was estimated in a subset of 157 patients by RNA decrease from days 0 to 7, and days 14 to 28. One-way ANOVA and subsequent Tukey's post hoc tests were used for groupwise comparisons. Mean (95% CI) HIV-1 RNA reductions from days 0 to 28 were 2.59 (2.45-2.73), 2.42 (2.27-2.57), and 2.13 (2.01-2.25) log(10) copies/ml for the EFV-, LPV/r-, and ATV/r-based treatment groups, respectively, with a significantly larger decrease in the EFV-based group at all time points compared with ATV/r (p < 0.0001), and with LPV/r at days 7-21 (p < 0.0001-0.03). LPV/r gave a greater RNA decrease compared with ATV/r from day 14 (p = 0.02). Phase 1 decay rate was significantly higher in the EFV group compared with LPV/r (p = 0.003) or ATV/r (p < 0.0001). No difference was found in phase 2 decrease. EFV-based treatment gave a more rapid decline in HIV-1 RNA than did either of the boosted protease inhibitor-based regimens. The observed differences may reflect different inherent regimen potencies.
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| 3. |
- Forsberg, Viviane, 1981-, et al.
(author)
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Photodetector of multilayer exfoliated MoS2 deposited on polyimide films
- 2018
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Conference paper (other academic/artistic)abstract
- We fabricated a photodetector based on multilayer molybdenum disulfide (MoS2) by micromechanical cleavage of a molybdenite crystal using a polyimide film. We deposited 40 nm of gold by vacuum sputtering and copper tape was used for the contacts. Without any surface treatment, we achieved high responsivity at different incident optical power. The calculated responsivity was 23 mA/W of incident optical power in the range between 400 and 800 nm. For the responsivity measurement it was estimated that MoS2 have a bandgap of 1.6 eV, which lies between monolayer and multilayer films. The thickness of the MoS2 thin film was determined by Raman spectroscopy evaluating the difference between the in plane and out of plane Raman modes. The measurement of IV curves indicated Ohmic contacts in respect to the Au regardless of the incident optical power. Our device fabrication was much simpler than previous reported devices and can be used to test the light absorption and luminescence capabilities of exfoliated MoS2.
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| 4. |
- Zhang, Renyun, et al.
(author)
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Soap-film coating : High-speed deposition of multilayer nanofilms
- 2013
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In: Scientific Reports. - Nature Publishing Group : Springer Science and Business Media LLC. - 2045-2322. ; 3, s. Art. no. 1477-
-
Journal article (peer-reviewed)abstract
- The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.
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| 5. |
- Alijagic, Andi, 1992-, et al.
(author)
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A Novel Nanosafety Approach Using Cell Painting, Metabolomics, and Lipidomics Captures the Cellular and Molecular Phenotypes Induced by the Unintentionally Formed Metal-Based (Nano)Particles
- 2023
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In: Cells. - : MDPI. - 2073-4409. ; 12:2
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Journal article (peer-reviewed)abstract
- Additive manufacturing (AM) or industrial 3D printing uses cutting-edge technologies and materials to produce a variety of complex products. However, the effects of the unintentionally emitted AM (nano)particles (AMPs) on human cells following inhalation, require further investigations. The physicochemical characterization of the AMPs, extracted from the filter of a Laser Powder Bed Fusion (L-PBF) 3D printer of iron-based materials, disclosed their complexity, in terms of size, shape, and chemistry. Cell Painting, a high-content screening (HCS) assay, was used to detect the subtle morphological changes elicited by the AMPs at the single cell resolution. The profiling of the cell morphological phenotypes, disclosed prominent concentration-dependent effects on the cytoskeleton, mitochondria, and the membranous structures of the cell. Furthermore, lipidomics confirmed that the AMPs induced the extensive membrane remodeling in the lung epithelial and macrophage co-culture cell model. To further elucidate the biological mechanisms of action, the targeted metabolomics unveiled several inflammation-related metabolites regulating the cell response to the AMP exposure. Overall, the AMP exposure led to the internalization, oxidative stress, cytoskeleton disruption, mitochondrial activation, membrane remodeling, and metabolic reprogramming of the lung epithelial cells and macrophages. We propose the approach of integrating Cell Painting with metabolomics and lipidomics, as an advanced nanosafety methodology, increasing the ability to capture the cellular and molecular phenotypes and the relevant biological mechanisms to the (nano)particle exposure.
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| 6. |
- Alijagic, Andi, 1992-, et al.
(author)
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Particle Safety Assessment in Additive Manufacturing : From Exposure Risks to Advanced Toxicology Testing.
- 2022
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In: Frontiers in Toxicology. - : Frontiers Media S.A.. - 2673-3080. ; 4
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Research review (peer-reviewed)abstract
- Additive manufacturing (AM) or industrial three-dimensional (3D) printing drives a new spectrum of design and production possibilities; pushing the boundaries both in the application by production of sophisticated products as well as the development of next-generation materials. AM technologies apply a diversity of feedstocks, including plastic, metallic, and ceramic particle powders with distinct size, shape, and surface chemistry. In addition, powders are often reused, which may change the particles' physicochemical properties and by that alter their toxic potential. The AM production technology commonly relies on a laser or electron beam to selectively melt or sinter particle powders. Large energy input on feedstock powders generates several byproducts, including varying amounts of virgin microparticles, nanoparticles, spatter, and volatile chemicals that are emitted in the working environment; throughout the production and processing phases. The micro and nanoscale size may enable particles to interact with and to cross biological barriers, which could, in turn, give rise to unexpected adverse outcomes, including inflammation, oxidative stress, activation of signaling pathways, genotoxicity, and carcinogenicity. Another important aspect of AM-associated risks is emission/leakage of mono- and oligomers due to polymer breakdown and high temperature transformation of chemicals from polymeric particles, both during production, use, and in vivo, including in target cells. These chemicals are potential inducers of direct toxicity, genotoxicity, and endocrine disruption. Nevertheless, understanding whether AM particle powders and their byproducts may exert adverse effects in humans is largely lacking and urges comprehensive safety assessment across the entire AM lifecycle-spanning from virgin and reused to airborne particles. Therefore, this review will detail: 1) brief overview of the AM feedstock powders, impact of reuse on particle physicochemical properties, main exposure pathways and protective measures in AM industry, 2) role of particle biological identity and key toxicological endpoints in the particle safety assessment, and 3) next-generation toxicology approaches in nanosafety for safety assessment in AM. Altogether, the proposed testing approach will enable a deeper understanding of existing and emerging particle and chemical safety challenges and provide a strategy for the development of cutting-edge methodologies for hazard identification and risk assessment in the AM industry.
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| 7. |
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| 8. |
- Bond, Luke, et al.
(author)
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Electrically conductive polymer-graphene composite material for selective laser sintering additive manufacturing
- 2024
-
In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE - The International Society for Optics and Photonics. - 9781510670068
-
Conference paper (peer-reviewed)abstract
- Additive manufacturing is rapidly growing, where selective laser sintering technology dominates for industrial use. In the case of polymer selective laser sintering, polyamide is the standard material. However, polyamide is an electrical insulator, and for specific applications, it would be desirable to be able to manufacture polymer-based electrically conductive parts. Electromagnetic Compatibility is one of the most significant targeted applications, where the introduction of electric vehicles raises new electromagnetic compatibility demands. The goal is, therefore, to develop an electrically conductive composite material for selective laser sintering using graphene as the additive. Composites are prepared by mixing polyamide, graphene, and additives with varying graphene/polyamide ratios. The aim of this investigation is the laser-assisted processing of the resulting graphene/polyamide composites with various parameters to sinter the material, forming a solid conductive structure. The structure is characterized using SEM and resistance measurements. Results show sheet resistance values of about 700Ω/sq after laser-assisted processing with good powder flowability.
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| 9. |
- Bruhn-Olszewska, Bozena, et al.
(author)
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Loss of Y in leukocytes as a risk factor for critical COVID-19 in men.
- 2022
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In: Genome medicine. - : Springer Science and Business Media LLC. - 1756-994X. ; 14:1
-
Journal article (peer-reviewed)abstract
- The COVID-19 pandemic, which has a prominent social and economic impact worldwide, shows a largely unexplained male bias for the severity and mortality of the disease. Loss of chromosome Y (LOY) is a risk factor candidate in COVID-19 due to its prior association with many chronic age-related diseases, and its impact on immune gene transcription.Publicly available scRNA-seq data of PBMC samples derived from male patients critically ill with COVID-19 were reanalyzed, and LOY status was added to the annotated cells. We further studied LOY in whole blood for 211 COVID-19 patients treated at intensive care units (ICU) from the first and second waves of the pandemic. Of these, 139 patients were subject to cell sorting for LOY analysis in granulocytes, low-density neutrophils (LDNs), monocytes, and PBMCs.Reanalysis of available scRNA-seq data revealed LDNs and monocytes as the cell types most affected by LOY. Subsequently, DNA analysis indicated that 46%, 32%, and 29% of critically ill patients showed LOY above 5% cut-off in LDNs, granulocytes, and monocytes, respectively. Hence, the myeloid lineage that is crucial for the development of severe COVID-19 phenotype is affected by LOY. Moreover, LOY correlated with increasing WHO score (median difference 1.59%, 95% HDI 0.46% to 2.71%, p=0.025), death during ICU treatment (median difference 1.46%, 95% HDI 0.47% to 2.43%, p=0.0036), and history of vessel disease (median difference 2.16%, 95% HDI 0.74% to 3.7%, p=0.004), among other variables. In 16 recovered patients, sampled during ICU stay and 93-143 days later, LOY decreased significantly in whole blood and PBMCs. Furthermore, the number of LDNs at the recovery stage decreased dramatically (median difference 76.4 per 10,000 cell sorting events, 95% HDI 55.5 to 104, p=6e-11).We present a link between LOY and an acute, life-threatening infectious disease. Furthermore, this study highlights LOY as the most prominent clonal mutation affecting the myeloid cell lineage during emergency myelopoiesis. The correlation between LOY level and COVID-19 severity might suggest that this mutation affects the functions of monocytes and neutrophils, which could have consequences for male innate immunity.
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| 10. |
- Forsberg, Viviane, 1981-, et al.
(author)
-
Printability of functional inkjet inks onto commercial inkjet substrates and a taylor made pigmented coated paper
- 2018
-
Conference paper (other academic/artistic)abstract
- Printed electronics are of increasing interest. The substrates used have primarily been plastics although the interest for cellulose-based substrates is increasing due to the environmental aspect as well as cost. The requirements of substrates for electronically active inks differs from graphical inks and therefore we have investigated a custom-made pigment based coated paper and compared it to commercial photo-papers and a coated PE film.Our goal with the study of different substrates was to select the most suitable substrate to print water based 2D materials inkjet inks for flexible electronics.The discovery of graphene, a layered material achieved from the exfoliation of graphite, has resulted in the study of other materials with similar properties to cover areas where graphene could not be used due to the absence of a bandgap in the material. For example in thin film transistors (TFT) a semiconductor layer is essential to enable turn on and off the device. This semiconductor layer can be achieved using various materials but particular interest have been dedicated to abundant and cheap 2D materials such as the transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2). To date, most of the dispersions based on TMDs use organic solvents or water solutions of surfactants. Previously we focus on the study of environmental friendly inks produced by liquid phase exfoliation (LPE) of MoS2 in water using cellulose stabilizers such as ethyl cellulose (EC), cellulose nanofibrils (CNF) and nanofibrilcellulose (NFC). We have study various aspects of the ink fabrication includi ng pH range, the source of MoS2, nanosheets thickness, particle size distribution, ink stabilizers, ink concentration, viscosity and surface tension. These inks have very low concentration requiring a number of printing passes to cover the substrate. Therefore the substrate selection is crucial as a large amount of solvent is to be absorb by the substrate. Our goal was to use such an ink to print electrodes of MoS2 into a paper substrate after substrate selection.Commercial photo papers, a commercial coated PE film and a tailor made multilayer pigment coated paper substrate were used for the substrate selection analysis. We print the substrates using a DIMATIX inkjet printer with a 10 pL printing head using the distillated water waveform supplied by the printer manufacturer. The voltage used was 23V and 4 nozzles were used for the print outs. The inkjet ink used was the organic PEDOT:PSS. We printed lines ranging from 1 pixel to 20 pixels with 1, 2 and 3 printing passes. The printing quality was evaluated through measurements of the waviness of the printed lines measured after imaging the printed samples with a SEM microscope. The line width measurement was done using the software from the SEM.We also evaluated the structure of the coatings using SEM and topography measurements. The ink penetration through the substrates was evaluated using Raman Spectroscopy. For the pigmented coated sample we measured 4% of ink penetration through the substrate for the 1pxl printed line printed once onto the paper. Cross-section SEM images of the printed lines were made to visualize the ink penetration into the substrate.Regarding the electrical conductivity of the printed samples, the differences in resistivity varying the width of the printed lines and the number of printed passes were evaluated. The resistivity of the printed electrodes was evaluated using the 2-points probe method. Before the resistivity measurements, the printed substrates were heated at 50°C and 100°C for 30 minutes in an oven.We choose the PEDOT:PSS ink because it is a low price ink compared to metal nanoparticles inks for printed electronics. The print outs had low resistivity at a few printing passes with no need for sintering at high temperatures. The MoS2 ink has a very high resistance at a few printing passes due to lower coverage of the substrate therefore for this ink these measurements were not possible to be made. The main pigment composition of the paper coatings of the substrates was evaluated using FT-IR and EDX, these data plus the coating structure evaluated by SEM was related to the print quality.The best in test papers were used to print MoS2 electrodes. After the printing tests, another step for the optimization of the MoS2 ink properties shall be carried out in future studies for better print quality. We also evaluated the surface energy of the substrates through contact angle measurements to match the surface tension of the PEDOT:PSS ink and later the MoS2 ink. Although the pigmented coated printing substrate did not show better results than the commercial photo papers and PE foil in terms of line quality, it shows the lowest resistivity and sufficient results for low cost recyclable electronics, which do not require high conductivity. Nevertheless, the substrate was very thin and it could even be used in magazines as traditional lightweight coated papers (LWC) are used but with the additional of a printed electronic feature.
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| 11. |
- Kanberg, Nelly, et al.
(author)
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Neurochemical signs of astrocytic and neuronal injury in acute COVID-19 normalizes during long-term follow-up.
- 2021
-
In: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 70
-
Journal article (peer-reviewed)abstract
- Neurologic manifestations are well-recognized features of coronavirus disease 2019 (COVID-19). However, the longitudinal association of biomarkers reflecting CNS impact and neurological symptoms is not known. We sought to determine whether plasma biomarkers of CNS injury were associated with neurologic sequelae after COVID-19.Patients with confirmed acute COVID-19 were studied prospectively. Neurological symptoms were recorded during the acute phase of the disease and at six months follow-up, and blood samples were collected longitudinally. Healthy age-matched individuals were included as controls. We analysed plasma concentrations of neurofilament light-chain (NfL), glial fibrillary acidic protein (GFAp), and growth differentiation factor 15 (GDF-15).One hundred patients with mild (n=24), moderate (n=28), and severe (n=48) COVID-19 were followed for a median (IQR) of 225 (187-262) days. In the acute phase, patients with severe COVID-19 had higher concentrations of NfL than all other groups (all p < 0·001), and higher GFAp than controls (p < 0·001). GFAp was also significantly increased in moderate disease (p < 0·05) compared with controls. NfL (r=0·53, p < 0·001) and GFAp (r=0·39, p < 0·001) correlated with GDF-15 during the acute phase. After six months, NfL and GFAp concentrations had normalized, with no persisting group differences. Despite this, 50 patients reported persistent neurological symptoms, most commonly fatigue (n=40), "brain-fog" (n=29), and changes in cognition (n=25). We found no correlation between persistent neurological symptoms and CNS injury biomarkers in the acute phase.The normalization of CNS injury biomarkers in all individuals, regardless of previous disease severity or persisting neurological symptoms, indicates that post COVID-19 neurological sequelae are not accompanied by ongoing CNS injury.The Swedish State Support for Clinical Research, SciLifeLab Sweden, and the Knut and Alice Wallenberg Foundation have provided funding for this project.
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| 12. |
- Söfteland, John M., 1977, et al.
(author)
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Longevity of anti-spike and anti-nucleocapsid antibodies after COVID-19 in solid organ transplant recipients compared to immunocompetent controls.
- 2022
-
In: American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. - : Elsevier BV. - 1600-6143. ; 22:4, s. 1245-1252
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Journal article (peer-reviewed)abstract
- Solid organ transplant recipients (SOTRs) are on lifelong immunosuppression, which may interfere with adaptive immunity to COVID-19. The data on dynamics and duration of antibody response in SOTRs are limited. This longitudinal study examined the longevity of both anti-spike (S)- and anti-nucleocapsid (N)-specific IgG-antibodies after COVID-19 in SOTRs compared to matched immunocompetent persons. SOTRs (n=65) were matched with controls (n=65) for COVID-19 disease severity, age, and sex in order of priority. Serum-IgG-antibodies against N- and S-antigens of SARS-CoV-2 were analyzed. At 1 and 9 months after COVID-19, anti-S-IgG detectability decreased from 91% to 82% in SOTRs versus 100% to 95% in controls, whereas the anti-N-IgG decreased from 63% to 29% in SOTRs versus 89% to 46% in controls. A matched paired analysis showed SOTRs having significantly lower levels of anti-N-IgG at all time points (1-month P=0.007, 3-months P<0.001, 6-months P=0.019 and 9-months P=0.021) but not anti-S-IgG at any time points. A mixed-model analysis confirmed these findings except for anti-S-IgG at one month (p=0.005) and identified severity score as the most important predictor of antibody response. SOTRs mount comparable S-specific, but not N-specific, antibody responses to SARS-CoV-2 infection compared to immunocompetent controls.
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| 13. |
- Tyrberg, Erika, et al.
(author)
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Higher plasma drug levels in elderly people living with HIV treated with darunavir
- 2021
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:2
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Journal article (peer-reviewed)abstract
- Background The proportion of elderly people living with HIV-1 (PLHIV) is rising. In older patients, comorbidities and concomitant medications are more frequent, increasing the risk of potential drug-drug interactions (PDDIs). Data on the pharmacokinetics of ART in individuals aged >= 65 years of age are scarce. We compared plasma drug levels of ART, PDDIs, and side-effects in PLHIV aged >= 65 years of age, with controls <= 49 years of age. Methods Patients >= 65 years of age and controls <= 49 years of age, all of whom were on stable treatment with atazanavir (ATV), darunavir (DRV), or efavirenz (EFV) were included cross-sectionally. Plasma drug levels of ART were analyzed, comorbidities, concomitant medication, adherence, and side-effects recorded, and PDDIs analyzed using drug interactions databases. Results Between 2013 and 2015, we included 100 individuals >= 65 years of age (study group) and 99 controls (<= 49 years of age). Steady-state DRV concentrations were significantly higher in the study group than in the control group (p = 0.047). In the ATV group there was a trend towards a significant difference (p = 0.056). No significant differences were found in the EFV arm. The DRV arm had a higher frequency of reported side-effects than the ATV and EFV arms in the study group (36.7% vs. 0% and 23.8% respectively (p = 0.014), with significant differences between DRV vs. ATV, and EFV vs. ATV). Conclusions Higher steady-state plasma levels of DRV and ATV (but not EFV) were found in PLHIV aged >= 65 years of age, compared to controls <= 49 years of age.
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| 14. |
- Wadell, M., et al.
(author)
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Challenges imposed by the COVID-19 pandemic on the Obstetrics and Gynecology residency program: a mixed-methods Swedish survey in the COPE Staff cohort study
- 2022
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In: Bmc Medical Education. - : Springer Science and Business Media LLC. - 1472-6920. ; 22:1
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Journal article (peer-reviewed)abstract
- Background To outline how the training program and work situation of residents in Obstetrics and Gynecology (OB-GYN) was affected by the pandemic and to illuminate how residents experienced these changes. Methods As part of the COVID-19 in Pregnancy and Early Childhood Staff (COPE Staff) cohort study, between January and May 2021, all participating residents were invited to answer a 28-question online Resident Survey focusing on their specialist education, work situation and experiences during the COVID-19 pandemic. Descriptive statistics were given in percentages for categorical variables and means and standard deviations (SD) for continuous variables. Univariate comparative analyses were performed with the use of the Pearson's Chi-2-test for dichotomous data. The association between residents' worry about the quality and length of their specialist training, with extra clinical hours and transfer to other healthcare institutions were assessed by multivariate logistic regression. Free text responses were analyzed by content analysis. Results Of the 162 participating OB-GYN residents, 69% expressed concern that the pandemic would have a negative impact on their training. Ninety-five (95%) reported cancellation/postponement of educational activities, 70% performed fewer surgeries and 27% had been transferred to other healthcare institutions where about half reported having gained more general knowledge as a physician. Working extra clinical hours was reported by 69% (7.4 +/- 5.3 hours per week) and 14% had considered changing their profession due to the pandemic. Senior residents, compared to junior residents, more often experienced cancelled/postponed clinical rotations (30% vs 15%, P=0.02) and reported performing fewer surgeries (P=0.02). The qualitative analysis highlighted the lack of surgical procedural training as a major concern for residents. Conclusion The COVID-19 pandemic has strongly impacted the training program and work situation of OB-GYN residents in Sweden. Residents were concerned over the negative impact of the pandemic on their training program and senior residents reported more missed educational opportunities as compared to junior residents. Program directors, head of institutions and clinical supervisors can use the problem areas pinpointed by this study to support residents and compensate for missed educational opportunities. While hands-on-training and operating time cannot be compensated for, the authors hope that the findings of the study can help develop new strategies to minimize the negative impact of the current and future pandemics on resident education and work situation.
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| 15. |
- Zhang, Renyun, et al.
(author)
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Cellulose-Based Fully Green Triboelectric Nanogenerators with Output Power Density of 300 W m−2
- 2020
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In: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 32:38
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Journal article (peer-reviewed)abstract
- Triboelectric nanogenerators (TENGs) have attracted increasing attention because of their excellent energy conversion efficiency, the diverse choice of materials, and their broad applications in energy harvesting devices and self-powered sensors. New materials have been explored, including green materials, but their performances have not yet reached the level of that for fluoropolymers. Here, a high-performance, fully green TENG (FG-TENG) using cellulose-based tribolayers is reported. It is shown that the FG-TENG has an output power density of above 300 W m−2, which is a new record for green-material-based TENGs. The high performance of the FG-TENG is due to the high positive charge density of the regenerated cellulose. The FG-TENG is stable after more than 30 000 cycles of operations in humidity of 30%–84%. This work demonstrates that high-performance TENGs can be made using natural green materials for a broad range of applications.
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| 16. |
- Zhang, Renyun, et al.
(author)
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Energy Harvesting Using Wastepaper-Based Triboelectric Nanogenerators
- 2023
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In: Advanced Engineering Materials. - : Wiley. - 1438-1656 .- 1527-2648. ; 25:11
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Journal article (peer-reviewed)abstract
- Inks and toners used for printing contain materials, such as polyester, with strong triboelectric properties to enhance the binding effects, making wastepaper, such as magazines and newspapers, good candidates for triboelectric materials. Herein, high-output power triboelectric nanogenerators (TENGs) that utilize wastepaper as triboelectric layers (wastepaper-based triboelectric nanogenerators (WP–TENGs)) are reported. Journal paper and office copy paper wastes are investigated. The results show that the maximum power densities of the WP–TENGs reach 43.5 W m−2, which is approximately 250 times the previously reported output of the TENG with a recycled triboelectric layer made from wastepaper. The maximum open circuit voltage (V OC) and short circuit current (I SC) are 774 V and 3.92 mA (784 mA m−2), respectively. These findings can be applied to extend the life cycle of printed papers for energy harvesting, and they can later be applied for materials recycling to enhance the sustainable development of our society.
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| 17. |
- Zhang, Renyun, et al.
(author)
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High-performance transparent and flexible electrodes made by flash-light sintering of gold nanoparticles
- 2018
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In: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:12, s. 7191-7198
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Journal article (peer-reviewed)abstract
- Metallic nanowire-based transparent electrodes (TEs) are potential alternatives to indium tin oxide (ITO). To achieve a high performance [sheet resistance (Rs) < 100 Ω/sq, transmittance (T%) > 90%], the nanowires must have a high length-to-diameter (L/D) ratio to minimize the number of wire-to-wire junctions. Attempts to produce TEs with gold nanowires have been made, and the results reveal difficulties in achieving the requirements. A successful strategy involves creating templated gold nanonetworks through multiple procedures. Here, we present a simple and efficient method that uses flash-light sintering of a gold nanonetwork film into gold TEs (Rs: 82.9 Ω/sq, T %: 91.79%) on a thin polycarbonate film (25 μm). The produced gold TEs have excellent mechanical, electrical, optical, and chemical stabilities. Mechanisms of the formation of gold nanonetworks and the effect of flash-light have been analyzed. Our findings provide a scalable process for producing transparent and flexible gold electrodes with a total processing time of less than 8 min without the use of heating, vacuum processing, and organic chemicals and without any material loss. This is possible because all the gold nanoparticles have been aggregated and filtrated on the filter membranes. The area density of gold is 0.094 g/m2 leading low material costs, which is very competitive with the price of commercial TEs.
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| 18. |
- Zhang, Renyun, et al.
(author)
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Photoconductivity of acid exfoliated and flash-light-processed MoS2 films
- 2018
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
-
Journal article (peer-reviewed)abstract
- MoS2 has been studied intensively during recent years as a semiconducting material in several fields, including optoelectronics, for applications such as solar cells and phototransistors. The photoresponse mechanisms of MoS2 have been discussed but are not fully understood, especially the phenomenon in which the photocurrent slowly increases. Here, we report on a study of the photoresponse flash-light-processed MoS2 films of different thicknesses and areas. The photoresponse of such films under different light intensities and bias voltages was measured, showing significant current changes with a quick response followed by a slow one upon exposure to pulsed light. Our in-depth study suggested that the slow response was due to the photothermal effect that heats the MoS2; this hypothesis was supported by the resistivity change at different temperatures. The results obtained from MoS2 films with various thicknesses indicated that the minority-carrier diffusion length was 1.36 mu m. This study explained the mechanism of the slow response of the MoS2 film and determined the effective thickness of MoS2 for a photoresponse to occur. The method used here for fabricating MoS2 films could be used for fabricating optoelectronic devices due to its simplicity.
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| 19. |
- Zhang, Renyun, et al.
(author)
-
Sensing body motions based on charges generated on the body
- 2019
-
In: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 63
-
Journal article (peer-reviewed)abstract
- The sensing of body motions is of great importance in areas such as healthcare, rehabilitation, and human-computer interactions. Different methods have been developed based on visual or electrical signals. However, such signals are acquired by external devices and are not intrinsic signals that are created on the body. Here, we report a new universal body motion sensor (UBS) to detect motions based on the intrinsic contact electrification (CE) of the skin or electrical induction (EI) of the body. The CE or EI generates charges on the body, leading to potential differences between the body and ground that can be measured to identify different body motions, such as motions of the head, arms, fingers, waist, legs, feet and toes. Proof-of-concept experiments have demonstrated that the UBS can be used to monitor the conditions of people with Parkinson's disease (PD) and to quantitatively monitor the recovery of those with a leg injury, suggesting great potential for healthcare applications.
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| 20. |
- Zhang, Renyun, et al.
(author)
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Triboelectric nanogenerators with ultrahigh current density enhanced by hydrogen bonding between nylon and graphene oxide
- 2023
-
In: Nano Energy. - 2211-2855 .- 2211-3282. ; 115
-
Journal article (peer-reviewed)abstract
- The triboelectric properties of the tribolayers are essential factors affecting the current density of triboelectric nanogenerators (TENGs). To enhance the current density, composites have been developed to tune their triboelectric properties. Previous studies have reported enhanced TENG performance with composite materials, primarily based on their composition, while chemical interactions between the components have been less analyzed. In this study, we report a novel approach to improve the current density of a TENG by introducing dipole-dipole interactions between a nylon filter membrane and graphene oxide (GO) through hydrogen bonds. The Raman spectroscopy confirmed the occurrence of the interactions resulting from hydrogen bonding. The enhancing mechanisms of hydrogen bonds were further analyzed by Kelvin probe force microscope (KPFM) measurement, which demonstrated that hydrogen bonding could influence the surface potential of the coated GO, leading to increased output of the nylon/GO@NFM TENG (NGN-TENG). Our results show that an ultrahigh current density of 1757 mA·m−2 was obtained with a 2 × 2 cm2 NGN-TENG. Additionally, we demonstrated the feasibility of using the NGN-TENG as a motion sensor to sense finger motions. These findings suggest that the introduction of hydrogen bonds in TENG composites can provide a promising route for improving their performance.
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| 21. |
- Zhang, Renyun, et al.
(author)
-
Wastepaper-based Triboelectric Nanogenerators
- 2023
-
In: Book of Abstracts EPNOE 2023. - : Graz University of Technology.
-
Conference paper (other academic/artistic)abstract
- nks and toners used for printing contain materials, such as polyester, with strong triboelectric properties to enhance the binding effects, making wastepaper, such as magazines and newspapers, good candidates for triboelectric materials. In this study, we report high- output power triboelectric nanogenerators (TENGs) that utilize wastepaper as triboelectric layers (wastepaper-based triboelectric nanogenerators (WP–TENGs)) [1]. Journal paper and office copy paper wastes are investigated. The results show that the maximum power densities of the WP–TENGs reach 43.5 W·m-2, which is approximately 250 times the previously reported output of the TENG with a recycled triboelectric layer made from wastepaper [2]. The maximum open circuit voltage (VOC) and short circuit current (ISC) are 774 V and 3.92 mA (784 mA m-2), respectively. These findings can be applied to extend the life cycle of printed papers for energy harvesting, and they can later be applied for materials recycling to enhance the sustainable development of our society.[1] Zhang, R., Hummelgård, M., Örtegren, J., Andersson, H., Olsen, M., Chen, W., Wang, P., Eivazi, A., Dahlström, C. & Norgren, M. Adv. Engin. Mater., in press, 2023; https://doi.org/10.1002/adem.202300107[2] Zhang, Z., Jie, Y., Zhu, J., Zhu, Z., Chen, H, Lu, Q., Zeng, Y., Cao, X., Wang, N. & Wang, Z. Nano Res. 15, 1109, 2022; https://doi.org/10.1007/s12274-021-3612-8
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| 22. |
- Åkerström, Magnus, 1981, et al.
(author)
-
The COPE Staff study : Study description and initial report regarding job satisfaction, work-life conflicts, stress, and burnout among Swedish maternal and neonatal healthcare workers during the COVID-19 pandemic
- 2023
-
In: International Journal of Gynecology & Obstetrics. - : John Wiley & Sons. - 0020-7292 .- 1879-3479. ; 162:3, s. 989-997
-
Journal article (peer-reviewed)abstract
- ObjectiveTo describe the study design of the COPE Staff cohort study on working conditions for maternal and neonatal healthcare workers (MNHCWs), and present baseline data regarding job satisfaction, work-life conflicts, stress, and burnout. MethodsBetween January and April 2021, 957 MNHCWs (administrative and medical staff) completed a baseline survey. Average levels of job satisfaction, work-life conflicts, stress, and burnout, and associations to perceived workload were assessed. ResultsThe average levels of job satisfaction, work-life conflicts, stress, and burnout were 68.6 (95% confidence interval [CI] 64.3-72.8), 42.6 (95% CI 37.3-48.0), 42.0 (95% CI 37.7-46.3), and 1.9 (95% CI 1.6-2.2), respectively. The respondents scoring above critical values indicating clinical burnout ranged between 3% and 18%, respectively, for the four burnout sub-dimensions. Women reported significantly higher levels of stress and burnout. Younger participants had lower job satisfaction and higher levels of work-life conflicts, stress, and burnout. Higher perceived workload was significantly associated with lower job satisfaction levels and higher levels of work-life conflicts, stress, and burnout. ConclusionsOur results indicate associations between MNHCWs perceived workload and job satisfaction, work-life conflicts, stress, and burnout during the COVID-19 pandemic. Eighteen percent scored above critical values for exhaustion.
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| 23. |
- Öberg, Rasmus, et al.
(author)
-
Characterization of carfentanil and thiofentanil using surface-enhanced raman spectroscopy and density functional theory
- 2024
-
In: Journal of Raman Spectroscopy. - : John Wiley & Sons. - 0377-0486 .- 1097-4555. ; 55:4, s. 481-492
-
Journal article (peer-reviewed)abstract
- Fentanyls are synthetic opioids up to 10,000 times more potent than morphine. Although initially developed for medical applications, fentanyl and its analogues have recently grown synonymous with the ongoing opioid epidemic. To combat the continued spread of these substances, there is a need for rapid and sensitive techniques for chemical detection. Surface-enhanced Raman spectroscopy (SERS) has the potential for trace detection of harmful chemical substances. However, vibrational spectra obtained by SERS often differ between SERS substrates, as well as compared with spectra from normal Raman (NR) spectroscopy. Herein, SERS and NR responses from two fentanyl analogues, carfentanil (CF) and thiofentanil (TF), were measured and analysed with support from density functional theory (DFT) modelling. Using commercially available silver nanopillar SERS substrates, the SERS signatures of samples diluted in acetonitrile between 0.01 and 1000 µg/mL were studied. Relative SERS peak intensities measured in the range of 220–1800 cm−1 vary with concentration, while SERS and NR spectra largely agree for CF at higher concentrations ((Formula presented.) 100 µg/mL). For TF, three distinct NR peaks at 262, 366 and 667 cm−1 are absent or strongly suppressed in the SERS spectrum, attributed to the lone-pair electrons of the thiophene's sulphur atom binding to the Ag surface. The concentration dependence of the Raman peak at (Formula presented.) 1000 cm−1, assigned to trigonal bending of the phenyl ring, approximately follows a Langmuir adsorption isotherm. This work elucidates similarities and differences between SERS and NR in fentanyl detection and discusses the chemical rationale behind these differences.
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| 24. |
- Öberg, Rasmus, et al.
(author)
-
UV-induced spectral and morphological changes in bacterial spores for inactivation assessment
- 2024
-
In: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 128:7, s. 1638-1646
-
Journal article (peer-reviewed)abstract
- The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure’s success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores’ spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone’s 1600–1700 cm–1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.
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| 25. |
- Alakpa, Enateri V., et al.
(author)
-
Bioprinted schwann and mesenchymal stem cell co-cultures for enhanced spatial control of neurite outgrowth
- 2023
-
In: Gels. - : MDPI. - 2310-2861. ; 9:3
-
Journal article (peer-reviewed)abstract
- Bioprinting nerve conduits supplemented with glial or stem cells is a promising approach to promote axonal regeneration in the injured nervous system. In this study, we examined the effects of different compositions of bioprinted fibrin hydrogels supplemented with Schwann cells and mesenchymal stem cells (MSCs) on cell viability, production of neurotrophic factors, and neurite outgrowth from adult sensory neurons. To reduce cell damage during bioprinting, we analyzed and optimized the shear stress magnitude and exposure time. The results demonstrated that fibrin hydrogel made from 9 mg/mL of fibrinogen and 50IE/mL of thrombin maintained the gel’s highest stability and cell viability. Gene transcription levels for neurotrophic factors were significantly higher in cultures containing Schwann cells. However, the amount of the secreted neurotrophic factors was similar in all co-cultures with the different ratios of Schwann cells and MSCs. By testing various co-culture combinations, we found that the number of Schwann cells can feasibly be reduced by half and still stimulate guided neurite outgrowth in a 3D-printed fibrin matrix. This study demonstrates that bioprinting can be used to develop nerve conduits with optimized cell compositions to guide axonal regeneration.
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| 26. |
- Almgren, Magnus, 1972, et al.
(author)
-
RICS-el : Building a national testbed for research and training on SCADA security (short paper)
- 2019
-
In: Lect. Notes Comput. Sci.. - Cham : Springer Nature. ; 11260 LNCS, s. 219-225, s. 219-225
-
Conference paper (peer-reviewed)abstract
- Trends show that cyber attacks targeting critical infrastructures are increasing, but security research for protecting such systems are challenging. There is a gap between the somewhat simplified models researchers at universities can sustain contra the complex systems at infrastructure owners that seldom can be used for direct research. There is also a lack of common datasets for research benchmarking. This paper presents a national experimental testbed for security research within supervisory control and data acquisition systems (SCADA), accessible for both research training and experiments. The virtualized testbed has been designed and implemented with both vendor experts and security researchers to balance the goals of realism with specific research needs. It includes a real SCADA product for energy management, a number of network zones, substation nodes, and a simulated power system. This environment enables creation of scenarios similar to real world utility scenarios, attack generation, development of defence mechanisms, and perhaps just as important: generating open datasets for comparative research evaluation.
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| 27. |
- Andersson, Elin, 1975, et al.
(author)
-
Type-dependent E6/E7 mRNA expression of single and multiple high-risk human papillomavirus infections in cervical neoplasia.
- 2012
-
In: Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology. - : Elsevier BV. - 1873-5967. ; 54:1, s. 61-5
-
Journal article (peer-reviewed)abstract
- Coinfection with multiple HPV types is common in cervical lesions, but the biological significance of the individual infections is difficult to establish. Expression of oncogenic E6/E7 HPV mRNA is correlated to risk of malignant progression, commercial assays for genotyping E6/E7 mRNA of all HR-HPV are lacking.
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| 28. |
- Andersson, Elin, 1975, et al.
(author)
-
Type-specific HPV E6/E7 mRNA detection by real-time PCR improves identification of cervical neoplasia.
- 2011
-
In: Journal of clinical microbiology. - 1098-660X. ; 49:11, s. 3794-3799
-
Journal article (peer-reviewed)abstract
- DNA-based HPV assays show high sensitivity but poor specificity in detecting high-grade cervical lesions. Assays detecting mRNA of oncogenic E6/E7 show higher specificity, but lack either detection of all high-risk HPV genotypes or the capacity to specify the detected genotypes. Therefore, a real-time PCR assay detecting type-specific E6/E7 mRNA was developed and the clinical performance evaluated. 210 cervical LBC (liquid based cytology) samples from 204 women were analysed for HPV DNA and mRNA with the in house real-time PCR as well as PreTect HPV-Proofer. The sensitivity of real-time PCR mRNA-detection to detect histologically confirmed CIN2+ (cervical intraepithelial neoplasia grade 2 or higher) were 0.91, compared to 0.95 for DNA-analysis. The specificity was 0.68 compared to 0.38, and the positive predictive value (PPV) was higher for mRNA (0.67 vs 0.52) without any loss in negative predictive value (NPV). The sensitivity of the real-time PCR mRNA-test was somewhat higher than for PreTect HPV-Proofer (0.83 vs 0.75), when analysing for the same genotypes. The specificity was similar (0.76 vs 0.77). When analysing for mRNA of the eight most common genotypes in cervical cancer (HPV16, 18, 31, 33, 35, 45, 52, 58), the sensitivity to detect CIN2+ lesions was 0.87 and the specificity 0.74, with a PPV of 0.70. In conclusion, real-time PCR for detection of HPV E6/E7 mRNA transcripts can be a sensitive and specific tool in screening and investigation of cervical neoplasia. The composition of HPV-types in mRNA-testing needs to be further investigated to optimize sensitivity and specificity.
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| 29. |
- Andersson, Henrik, Dr, 1975-, et al.
(author)
-
PEDOT : PSS thermoelectric generators printed on paper substrates
- 2019
-
In: Journal of Low Power Electronics and Applications. - : MDPI AG. - 2079-9268. ; 9:2
-
Journal article (peer-reviewed)abstract
- Flexible electronics is a field gathering a growing interest among researchers and companies with widely varying applications, such as organic light emitting diodes, transistors as well as many different sensors. If the circuit should be portable or off-grid, the power sources available are batteries, supercapacitors or some type of power generator. Thermoelectric generators produce electrical energy by the diffusion of charge carriers in response to heat flux caused by a temperature gradient between junctions of dissimilar materials. As wearables, flexible electronics and intelligent packaging applications increase, there is a need for low-cost, recyclable and printable power sources. For such applications, printed thermoelectric generators (TEGs) are an interesting power source, which can also be combined with printable energy storage, such as supercapacitors. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), or PEDOT:PSS, is a conductive polymer that has gathered interest as a thermoelectric material. Plastic substrates are commonly used for printed electronics, but an interesting and emerging alternative is to use paper. In this article, a printed thermoelectric generator consisting of PEDOT:PSS and silver inks was printed on two common types of paper substrates, which could be used to power electronic circuits on paper.
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| 30. |
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| 31. |
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| 32. |
- Andersson, Magnus, 1975-
(author)
-
Construction of force measuring optical tweezers instrumentation and investigations of biophysical properties of bacterial adhesion organelles
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- Optical tweezers are a technique in which microscopic-sized particles, including living cells and bacteria, can be non-intrusively trapped with high accuracy solely using focused light. The technique has therefore become a powerful tool in the field of biophysics. Optical tweezers thereby provide outstanding manipulation possibilities of cells as well as semi-transparent materials, both non-invasively and non-destructively, in biological systems. In addition, optical tweezers can measure minute forces (< 10-12 N), probe molecular interactions and their energy landscapes, and apply both static and dynamic forces in biological systems in a controlled manner. The assessment of intermolecular forces with force measuring optical tweezers, and thereby the biomechanical structure of biological objects, has therefore considerably facilitated our understanding of interactions and structures of biological systems. Adhesive bacterial organelles, so called pili, mediate adhesion to host cells and are therefore crucial for the initial bacterial-cell contact. Thus, they serve as an important virulence factor. The investigation of pili, both their biogenesis and their expected in vivo properties, brings information that can be of importance for the design of new drugs to prevent bacterial infections, which is crucial in the era of increased bacterial resistance towards antibiotics. In this thesis, an experimental setup of a force measuring optical tweezers system and the results of a number of biomechanical investigations of adhesive bacterial organelles are presented. Force measuring optical tweezers have been used to characterize three different types of adhesive organelles under various conditions, P, type 1, and S pili, which all are expressed by uropathogenic Escherichia coli. A quantitative biophysical force-extension model, built upon the structure and force response, has been developed. It is found, that this model describes the biomechanical properties for all three pili in an excellent way. Various parameters in their energy landscape, e.g., bond lengths and transition barrier heights, are assessed and the difference in behavior is compared. The work has resulted in a method that in a swift way allows us to probe different types of pili with high force and high spatial resolution, which has provided an enhanced understanding of the biomechanical function of these pili.
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| 33. |
- Andersson, Magnus, 1975
(author)
-
De svenska bankernas industrifinansiering under sista halvan av 1800-talet. Bankkris, tillsyn och reglering.
- 2017
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In: Tolfte Ekonomisk-historiska mötet i Stockholm 13 oktober 2017.
-
Conference paper (other academic/artistic)abstract
- Från 1870-talet tog affärsbankerna i allt större omfattning över finansiering av större projekt från handelshusen. Speciellt när det handlar om samarbeten med de framväxande industriella företagen. Syftet med pappret är att studera industrifinansiering under andra halvan av 1800-talet. Finansieringen skedde dels via reverser, obligationer och via diskontering av växlar. Det här pappret fokuserar på den typen av finansiering, men med tyngdpunkt på den kris som drabbade banksystemet 1878-1879 och dess långsiktiga verkningar. Speciellt studeras hur Stockholms Enskilda Banks kreditportfölj byggdes upp under 1870-talet och de dubbla svårigheter banken fick med sin finansiering av både bruk och järnvägsetablering och på vilka sätt de lyckades reda upp svårigheterna. Dels via egna ansträngningar, men också via institutionella ingripanden från Riksbanken. I den kris som drabbade järnvägsetableringarna grep Riksbanken in med finansiering via Järnvägshypoteksfonden. Förtroendet behövde på sikt återupprättas för obligationssystemet. Inrättandet av Järnvägshypoteksfonden i syfte att rädda banker ur en svår likviditetskris är ett tydligt exempel på en institutionell åtgärd, med ett långsiktigt syfte att reglera och styra upp kreditmarknaden. Riksgäldskontoret administrerade fonden, men den var en del av Riksbankens politik. Reformerna fortsatte sedan med att Riksbanken år 1886 fick absolut ensamrätt för sedelutgivning.
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| 34. |
- Andersson, Magnus, 1975
(author)
-
Den europeiska varu- och kreditmarknaden under 1700-talet. Handel och sjöfart med Göteborg som utgångspunkt.
- 2016
-
Book (other academic/artistic)abstract
- 1700-talets Sverige var en dynamisk tid med stora politiska svängningar, utgående från såväl kungahus som riksdag. Handel och affärsliv hade att hantera hattpartiets generösa subventionspolitik på bästa sätt och senare mösspartiets indragningar och räfst. Trots den föränderliga spelplanen utvecklades handel och sjöfart på ett dramatiskt sätt. För Göteborg handlade det om export av järn och trä, men under senare hälften av århundradet, framförallt om den mycket lönsamma exporten av sillprodukter, som skapade enorma förmögenheter åt handelshusen. Det expansiva näringslivet krävde mycket kapital. Utan några egentliga banker utvecklades ett system av kreditmöjligheter som fungerade mycket väl. Kortfristiga lån kunde erhållas genom växlar och assignationer, långfristiga som lån av handelshus eller bankirer. Med väl fungerade växel- och konkurslagar som grund hanterades fallissemang snabbt och smidigt. Fram tonar ett mycket avancerat samhälle ännu långt ifrån tekniska hjälpmedel och sentida ekonomiska innovationer.
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| 35. |
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| 36. |
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| 37. |
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| 38. |
- Andersson, Magnus, 1975
(author)
-
Omvälvningarnas tid: Handelshuset Ekman i Göteborg på en europeisk kreditmarknad 1790–1820
- 2011
-
Doctoral thesis (other academic/artistic)abstract
- The purpose of this doctoral dissertation is to chart and analyze the flow of payments and credits to and from Gothenburg for the period 1790−1820, with a special interest in the transactions involving The Merchant House Ekman & Co. Both bills of exchange transactions within Ekman & Co and protested bills of exchange for other firms are studied. Markus A. Denzel’s model of Cashless Payment is an instrument to study how bills of exchange were used to ease payments and credit relations in the European Early Modern Credit market between 1790 and 1820. European trade possibilities for the period 1790−1820 are discussed in chapter III. The period under scrutiny was rather dramatic with economic and political changes. In Great Britain there was the industrial revolution and France experienced the great political revolution, followed by the Napoleonic wars. Chapter IV explores the credit- and bill of exchange markets. Since protested bills of exchange and different ways to deal with the problems that occur are important, this dissertation examines protested bills of exchange for two periods 1798−1800 and 1811−1812. The reasons for protesting bills of exchange are either lack of acceptance or lack of payment, both of which are common in this analysis. As a consequence there were no more endorsement possibilities. Chapter V describes the business of The Merchant House Ekman for the period 1790−1800, with special interest in the bills of exchange transactions. Peter III Ekman started his business ca 1760. He realized the importance of European contacts and from early on he traded with Merchants in Amsterdam, Hamburg, Greifswald, Wolgast and Stralsund. During the period 1790−1800 he was one of the most important producers of salted herring in Gothenburg. As a return good he imported grain from Merchant houses in the Baltic Sea. He imported the important salt by using his own ships. Ekman’s credit transactions in the form of bills of exchange contracts are of central importance, but the difficulty with the bills of exchange transactions is that there are no obvious connections with the commodity transactions. Because of endorsement, it is impossible to tell exactly what bill of exchange belonged to a certain amount of traded commodity. Chapter VI examines the Ekman & Co shift from mostly trading in herring and iron to concentrate on colonial trade at the time of war. Concerning credit relations, a database has been created for bills of exchange dating from 1810, which is then used to analyze the credit relations that Ekman & Co had with other firms in the European market. The dissertation shows the benefits of discounting and how the endorsements were used, as well as the fact that the Cashless Payments system with the bills of exchange transactions worked. When the system failed there was an effective law that solved the problem. All of this is further evidence that Gothenburg was an integrated part of the European financial system.
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| 39. |
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| 40. |
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| 41. |
- Andersson, Magnus, et al.
(author)
-
Structural Dynamics of Light-Driven Proton Pumps
- 2009
-
In: Structure. - : Elsevier BV. - 0969-2126 .- 1878-4186. ; 17:9, s. 1265-1275
-
Journal article (peer-reviewed)abstract
- Bacteriorhodopsin and proteorhodopsin are simple heptahelical proton pumps containing a retinal chromophore covalently bound to helix G via a protonated Schiff base. Following the absorption of a photon, all-trans retinal is isomerized to a 13-cis conformation, initiating a sequence of conformational changes driving vectorial proton transport. In this study we apply time-resolved wide-angle X-ray scattering to visualize in real time the helical motions associated with proton pumping by bacteriorhodopsin and proteorhodopsin. Our results establish that three conformational states are required to describe their photocycles. Significant motions of the cytoplasmic half of helix F and the extracellular half of helix C are observed prior to the primary proton transfer event, which increase in amplitude following proton transfer. These results both simplify the structural description to emerge from intermediate trapping studies of bacteriorhodopsin and reveal shared dynamical principles for proton pumping.
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| 42. |
- Andersson, Magnus, 1975
(author)
-
Tidig bankverksamhet i Sverige under industrialiseringsprocessen 1850-1920
- 2021
-
Book (other academic/artistic)abstract
- Under perioden 1850-1920 utvecklades Sverige till en industrination. Industrialiseringen medförde att kreditmarknaden och bankväsendet moderniserades. Vid industrialiseringsprocessens inledning bildades ett utvecklingsblock kring handeln, industrin, kommunikationerna samt kredit- och bankväsendet. Under 1870-talet började bankerna med obligationsfinansiering. Det viktigaste användningsområdet blev att finansiera infrastrukturen via en utbyggnad av järnvägsnätet. Det statliga stambanenätet kompletterades med en stor mängd privatfinansierade järnvägssträckningar. Kring affärsbankerna skapades så småningom sfärer av anknutna företag. Bankerna kom därmed att spela en avgörande roll i den ekonomiska utvecklingen. Som exempel kan nämnas Stockholms Enskilda Bank och de företag, som under 1900-talet har stått familjen Wallenberg nära. Den viktiga industrifinansieringen och transportfinansieringen bildade en stabil grund för Sveriges utveckling mot en modern industrination.
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| 43. |
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| 44. |
- Andersson, Magnus, 1975
(author)
-
Trust in early modern credit relations.
- 2012
-
In: Paper presented: Preindustrial Flows and Contacts in and between European Cities/Towns. Workshop in Gothenburg, September 2012..
-
Conference paper (other academic/artistic)
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| 45. |
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| 46. |
- Andersson, Peter, 1975, et al.
(author)
-
Cylindrical ionization chamber response in static and dynamic 6 and 15 MV photon beams
- 2023
-
In: Biomedical Engineering & Physics Express. - : Institute of Physics. - 2057-1976. ; 9:2
-
Journal article (peer-reviewed)abstract
- Purpose. To investigate the response of the CC13 ionization chamber under non-reference photon beam conditions, focusing on penumbra and build-up regions of static fields and on dynamic intensity-modulated beams. Methods. Measurements were performed in 6 MV 100 × 100, 20 × 100, and 20 × 20 mm2 static fields. Monte Carlo calculations were performed for the static fields and for 6 and 15 MV dynamic beam sequences using a Varian multi-leaf collimator. The chamber was modelled using EGSnrc egs_chamber software. Conversion factors were calculated by relating the absorbed dose to air in the chamber air cavity to the absorbed dose to water. Correction and point-dose correction factors were calculated to quantify the conversion factor variations. Results. The correction factors for positions on the beam central axis and at the penumbra centre were 0.98-1.02 for all static fields and depths investigated. The largest corrections were obtained for chamber positions beyond penumbra centre in the off-axis direction. Point-dose correction factors were 0.54-0.71 at 100 mm depth and their magnitude increased with decreasing field size and measurement depth. Factors of 0.99-1.03 were obtained inside and near the integrated penumbra of the dynamic field at 100 mm depth, and of 0.92-0.94 beyond the integrated penumbra centre. The variations in the ionization chamber response across the integrated dynamic penumbra qualitatively followed the behaviour across penumbra of static fields. Conclusions. Without corrections, the CC13 chamber was of limited usefulness for profile measurements in 20-mm-wide fields. However, measurements in dynamic small irregular beam openings resembling the conditions of pre-treatment patient quality assurance were feasible. Uncorrected ionization chamber response could be applied for dose verification at 100 mm depth inside and close to large gradients of dynamically accumulating high- and low-dose regions assuming 3% tolerance between measured and calculated doses. © 2023 The Author(s).
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| 47. |
- Andersson, Rina Argelia, 1975-
(author)
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Lipid biomarkers and other geochemical indicators in paleoenvironmental studies of two Arctic systems : a Russian permafrost peatland and marine sediments from the Lomonosov Ridge
- 2012
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Doctoral thesis (other academic/artistic)abstract
- The reconstruction of past environmental conditions is a fascinating research area that attracts the interest of many individuals in various geological disciplines. Paleoenvironmental reconstruction studies can shed light on the understanding of past climates and are a key to the prediction of future climate changes and their consequences. These studies take on special significance when focused on areas sensitive to climate change. The Arctic region, which is experiencing dramatic changes today in its peatlands and in its ocean, is prime example. The entire region plays a major role in global climate changes and has recently received considerable interest because of the potential feedbacks to climate change and its importance in the global carbon cycle.For a better understanding of the role of Arctic peatlands and the Arctic Ocean to global climate changes, more records of past conditions and changes in the region are needed. This work applies different geochemical proxies, with special emphasis on lipid biomarkers, to the study of a permafrost peat deposit collected from the Eastern European Russian Arctic and a marine core retrieved from the Lomonosov Ridge in the central Arctic Ocean. The results reported of this study show that molecular stratigraphy obtained from the analysis of lipid biomarkers in both peat and marine profiles, combined with other environmental proxies, can contribute significantly to the study of Arctic ecosystems of the past.
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| 48. |
- Andersson Trojer, Markus, 1981, et al.
(author)
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Synthesis and polymerisation of maleolyl-L-histidine monomers and addition of histidine to an ethylene-alt-maleic co-polymer
- 2012
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In: Journal of Polymer Research. - : Springer Science and Business Media LLC. - 1572-8935 .- 1022-9760. ; 19:2, s. 9821-9829
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Journal article (peer-reviewed)abstract
- This work has investigated two routes of synthesising polymers containing L-histidine using maleimide chemistry; grafting of histidine onto an ethylene-alt-maleic anhydride copolymer and AIBN (azobisisobutyronitrile) initiated radical polymerisation of the monomer maleoyl-L-histidine. The grafting technique and monomer synthesis are utilising the maleimide formation between the primary amine of histidine and maleic anhydride. The reactions are conveniently carried out in one step with good yields. The copolymers containing L-histidine were prepared by reacting L-histidine or L-histidine methyl ester with poly(ethylene-alt maleic anhydride) in DMSO at 50 °C for 8–16 h with 80% yields independent of the degree of substitution. The monomer maleoyl-L-histidine was synthesised by reacting histidine and maleic anhydride in acetic acid and the monomer was subsequently polymerised by AIBN radical initiation in DMSO at 80 °C for 48 h to yield poly(N-histidyl maleimide). The resulting polymer had a different optical rotation ([α]D20 = −11) than the monomer ([α]D20 = +25), which is ascribed to the threo-diisotactic and/or threo-disyndiotactic stereoregularity of the polymer.
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| 49. |
- Andree, Maria, et al.
(author)
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Knowledge Products from Close-To-Practice Research
- 2024
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In: Round table presentation at the NERA-conference, 6-8 March, Malmö University.
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Conference paper (other academic/artistic)abstract
- ‘Close-to-practice research’ has received increased attention across the Nordic countries. Following the British Education Research Association (BERA), the notion of ‘close-to-practice research’ is used to refer to educational research that is based on problems in practice, often involves researchers working in partnership with practitioners in schools and addresses issues of relevance to practitioners. This roundtable focuses on how close-to-practice research can contribute to the knowledge base of the teaching profession by bringing together perspectives from didactics, school improvement and educational policy. More specifically, the interest is directed toward what characterizes the knowledge produced through practice-based research that may have significance for teachers' professional knowledge base and practice. The roundtable conversation builds on a previous analysis of what kinds of knowledge products are generated in didactic close-to-practice research where teachers and researchers work together within the research environment Stockholm Teaching & Learning Studies. As a result of this analysis a typology of knowledge products was proposed including: (i) descriptions of knowing, (ii) teaching design, (iii) didactic examples and (iv) methodological tools. It has been proposed that additional knowledge products may be developed, such as artifacts to be used in teaching (e.g. lesson plans, visual representations). The roundtable will include the following points of discussion: 1) a brief presentation of the typology, 2) challenging and developing the typology of knowledge products proposed by previous research by investigating different cases of close-to-practice research from traditions of action research and practice-developing research within subject-didactics, and 3) discussing how the notion of knowledge products may contribute to advancing the conversation on cumulativity in the field of educational research in general, and in relation to syntheses of close-to-practice research in particular. The participants will be engaged in conversations on the desirability and feasibility of striving towards cumulativity.
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| 50. |
- Balliu, Enkeleda, PhD student, et al.
(author)
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Laser processing of graphene oxide on different coated paper substrates
- 2016
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In: 14th TAPPI Advanced Coating Symposium 2016. - : TAPPI Press. - 9781510877658 ; , s. 97-101
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Conference paper (peer-reviewed)abstract
- Development of printed electronics is increasing each year, where many electrical components such as transistors and sensors are now printable. The most commonly used substrate have been plastics, but there is an increasing interest in using paper as substrate. The paper industry is a very large and mature industry with large production capacity and well developed processes. It is therefore of interest to investigate how it would be possible to combine printed electronics and paper based products. This can for example be to print sensors on packages, to use large scale roll-to-roll production for solar cells. To be able to achieve such goals it is of importance to develop methods of applying electrically active materials in the large, high speed roll-to-roll processes used in the paper industry. In this article we discuss coating of graphene oxide (GO) on large areas after which it is selectively reduced into electrically conductive reduced graphene oxide (rGO) by laser processing. Graphene oxide is an inexpensive, carbon based material very suitable to be deposited as a coating, and the selective activation of makes it possible to fabricate conductive patterns at high speeds. We have evaluated several different paper substrates on which GO was coated. The reduction was performed using an 532 nm laser source and the results are promising, showing that it is possible to fabricate selectively conductive patterns on paper substrates by coating and reduction of GO.
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