| 1. |
- Barrat, Jean-Louis, et al.
(författare)
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Soft matter roadmap
- 2024
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Ingår i: Journal of Physics. - : Institute of Physics Publishing (IOPP). - 2515-7639. ; 7:1
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Forskningsöversikt (refereegranskat)abstract
- Soft materials are usually defined as materials made of mesoscopic entities, often self-organised, sensitive to thermal fluctuations and to weak perturbations. Archetypal examples are colloids, polymers, amphiphiles, liquid crystals, foams. The importance of soft materials in everyday commodity products, as well as in technological applications, is enormous, and controlling or improving their properties is the focus of many efforts. From a fundamental perspective, the possibility of manipulating soft material properties, by tuning interactions between constituents and by applying external perturbations, gives rise to an almost unlimited variety in physical properties. Together with the relative ease to observe and characterise them, this renders soft matter systems powerful model systems to investigate statistical physics phenomena, many of them relevant as well to hard condensed matter systems. Understanding the emerging properties from mesoscale constituents still poses enormous challenges, which have stimulated a wealth of new experimental approaches, including the synthesis of new systems with, e.g. tailored self-assembling properties, or novel experimental techniques in imaging, scattering or rheology. Theoretical and numerical methods, and coarse-grained models, have become central to predict physical properties of soft materials, while computational approaches that also use machine learning tools are playing a progressively major role in many investigations. This Roadmap intends to give a broad overview of recent and possible future activities in the field of soft materials, with experts covering various developments and challenges in material synthesis and characterisation, instrumental, simulation and theoretical methods as well as general concepts.
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| 2. |
- Simons, Sami O., et al.
(författare)
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Chronic obstructive pulmonary disease and atrial fibrillation an interdisciplinary perspective
- 2021
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Ingår i: European Heart Journal. - : OXFORD UNIV PRESS. - 0195-668X .- 1522-9645. ; 42:5
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Forskningsöversikt (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be similar to 25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening.
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| 3. |
- Brunk, Elizabeth, et al.
(författare)
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Recon3D enables a three-dimensional view of gene variation in human metabolism
- 2018
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 36:3, s. 272-281
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Tidskriftsartikel (refereegranskat)abstract
- Genome-scale network reconstructions have helped uncover the molecular basis of metabolism. Here we present Recon3D, a computational resource that includes three-dimensional (3D) metabolite and protein structure data and enables integrated analyses of metabolic functions in humans. We use Recon3D to functionally characterize mutations associated with disease, and identify metabolic response signatures that are caused by exposure to certain drugs. Recon3D represents the most comprehensive human metabolic network model to date, accounting for 3,288 open reading frames (representing 17% of functionally annotated human genes), 13,543 metabolic reactions involving 4,140 unique metabolites, and 12,890 protein structures. These data provide a unique resource for investigating molecular mechanisms of human metabolism. Recon3D is available at http://vmh.life.
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| 4. |
- Danilczuk, M., et al.
(författare)
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Ammonium Dithionate – a New Material for Highly Sensitive EPR Dosimetry
- 2008
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Institutionen för fysik, kemi och biologi. - 1386-1425 .- 1873-3557. ; 69:1, s. 18-21
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline ammonium dithionate has been examined for its radiation response in the low dose range (< 5 Gy) using EPR technique. The •SO3- radical ion was detected as a single EPR line with a peak-to-peak derivative width of ca. 0.44 mT in irradiated samples and its intensity was found to vary linearly with dose. At equal and moderate settings of microwave power and modulation amplitude ammonium dithionate was at least 7 times more sensitive than L-alanine which is the most common EPR dosimeter standard. Pulse experiments were performed on the powder samples to obtain the longitudinal relaxation time. These and microwave saturation experiments served to indicate the optimal microwave power to be applied during measurements as an EPR dosimeter for best sensitivity of this material. It is thus claimed that ammonium dithionate has excellent potential to become an EPR dosimeter with a low limit of the measurable dose for cases where tissue equivalence is not required or can be corrected for.
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| 5. |
- Danilczuk, M., et al.
(författare)
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Development of nickel-doped lithium formate as potential EPR dosimeter for low dose determination
- 2007
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Ingår i: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425. ; 67:5, s. 1370-1373
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Tidskriftsartikel (refereegranskat)abstract
- EPR dosimetry employing l-α-alanine has been in vogue during the past few years, due to its tissue equivalence and linear dose response. However, l-α-alanine dosimetry has been improved during the past years, the sensitivity of this material is still too low for clinical applications. Polycrystalline lithium formate doped with NiCl2 was therefore examined for radiation response in the dose range of clinical interest (<5 Gy) using CW EPR and pulse EPR techniques. At equal and moderate settings of microwave power and modulation amplitude lithium formate doped with 1.6 wt% of NiCl2 was almost four times more sensitive compared to l-α-alanine, which is the most common EPR dosimeter standard. It was shown that the nickel-doped lithium formate has an excellent radiation response with a low limit of the measurable dose, and a linear dose response in the range 1–5 Gy. The relaxation and power saturation studies showed that high microwave power can be applied during measurements to improve the sensitivity of this material as an EPR dosimeter. These results show that lithium formate doped with Ni(II) exhibits promising properties required for further development of an EPR dosimeter in the dose range typical for clinical dosimetry.
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| 6. |
- Gustafsson, Håkan, et al.
(författare)
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Enhanced sensitivity of lithium dithionates doped with rhodium and nickel for EPR dosimetry
- 2005
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Ingår i: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425. ; 62:1-3, s. 614-620
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Tidskriftsartikel (refereegranskat)abstract
- Electron paramagnetic resonance (EPR) studies of X-irradiated lithium dithionate, Li2S2O6·2H2O, doped with Ni and Rh have shown that these impurities enhance the yield of radicals formed by X-irradiation at room temperature. The signal in the doped samples, measured peak-to-peak of the single EPR derivative line attributed to the SO3− anion was about 3–4 times that of the pure lithium dithionate and more than 10 times stronger than the alanine signal. These impurities also shortened the spin-lattice relaxation time, T1, which gives the possibility to measure the doped samples at a higher microwave power. This implies that sensitivity could be further enhanced in the already sensitive EPR dosimeter material lithium dithionate.
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| 7. |
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| 8. |
- Pattabiraman, M., et al.
(författare)
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Annealing effect on transport properties of Nd0.67Sr0.33MnO3 thin films
- 2000
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Ingår i: Pramana (Bangalore). - : Springer Science and Business Media LLC. - 0304-4289 .- 0973-7111. ; 55:3, s. 455-469
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Tidskriftsartikel (refereegranskat)abstract
- Annealing dependence of the lattice parameter, resistivity, magnetoresistance and thermopower have been studied on Nd0.87Sr0.33MnO3 thin films deposited on LaAlO3 and alumina substrates by pulsed laser ablation. Upon annealing at 800 degrees C and 1000 degrees C the lattice constant of the LaAlO3 film tends toward that of the bulk target due to reduction in oxygen vacancies. This results in a metal-insulator transition at temperatures which increase with progressive annealing along with a decrease in the observed low temperature MR. Using a magnon scattering model we estimate the e(g) bandwidth of the film annealed at 1000 degrees C and show that the magnon contribution to the resistivity is suppressed in a highly oxygen deficient film and gains prominence only upon subsequent annealing. We also show that upon annealing, the polaron concentration and the spin cluster size increases in the paramagnetic phase, using an adiabatic polaron hopping model which takes into account an exchange dependent activation energy above the resistivity peak.
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| 9. |
- Sastry, M.D., et al.
(författare)
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Dynamical effects and ergodicity in the dipolar glass phase : Evidence from time-domain EPR and phase memory time studies of AsO44- in Rb1-x(NH4)xH2PO4 (x = 0,0.5,1)
- 2006
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 18:17, s. 4265-4284
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Tidskriftsartikel (refereegranskat)abstract
- Three-pulse electron spin echo envelope modulation (ESEEM), hyperfine sublevel correlation spectroscopy (HYSCORE) investigations and two-pulse electron spin echo (ESE) measurements of phase memory time TM, were carried out, in the 20-200 K temperature range, on an AsO44- paramagnetic probe stabilized in RbH2PO4 (RDP), NH4H2PO4 (ADP), and dipolar glass Rb0.5(NH4)0.5H2PO4 (RADP). The results obtained on ADP revealed hyperfine interaction of the probe ion with the 14N of the ammonium ion, the coupling constant satisfying the condition of 'cancellation' at a field of 480 mT. The ammonium ion was found to be in two different sites in ADP, which became indistinguishable on the formation of dipolar glass RADP. These results were confirmed by HYSCORE spectral measurements. The fast Fourier transform (FFT) spectra of three-pulse ESEEM decays have clearly revealed the interaction with protons in the bond both in ADP and RDP, and in RADP with an averaged coupling constant. The phase memory times in RADP exhibited strong temperature dependence and were found to be dependent on the nuclear spin quantum number mI of 75As. The temperature dependence of TM exhibited a well-defined maximum around 90 K, coinciding with the temperature of onset of 'freezing' in Rb0.5(NH4)0.5H2PO 4. This is symptomatic of dynamic fluctuations in the dipolar glass phase, with onset around 150 K, going through a maximum around 90 K and slowing down on further cooling. These results suggest that in RADP, a dynamical mechanism with progressive slowing down below 90 K is operative in the glass formation. This implies that the RADP system, with x = 0.5, exists in an ergodic relaxor (R)-state in the 20-200 K temperature range wherein every fluctuating monodomain can be viewed as statistically representative of the whole sample. © IOP Publishing Ltd.
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| 10. |
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| 11. |
- Cook, A, et al.
(författare)
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Neonatal invasive candidiasis in low- and middle-income countries: Data from the NeoOBS study
- 2023
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Ingår i: Medical mycology. - : Oxford University Press (OUP). - 1460-2709 .- 1369-3786. ; 61:3
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Tidskriftsartikel (refereegranskat)abstract
- Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole-resistant Candida spp. isolates in low- and middle-income countries (LMICs) compared to high-income countries (HICs). We describe the epidemiology, Candida spp. distribution, treatment, and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalized infants <60 days postnatal age with sepsis (August 2018–February 2021). A total of 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28–34), and median birth weight was 1270 gr (interquartile range [IQR]: 990–1692). Only a minority had high-risk criteria, such as being born <28 weeks, 19% (24/127), or birth weight <1000 gr, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%), and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole-resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrollment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines.
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| 12. |
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| 13. |
- Lund, Eva, et al.
(författare)
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Compounds of Li-6 and natural Li for EPR dosimetry in photon/neutron mixed radiation fields
- 2004
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425 .- 1873-3557. ; 60:6, s. 1319-1326
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Tidskriftsartikel (refereegranskat)abstract
- Formates and dithionates of Li-6, enriched and Li-7 in natural composition of Li offer a possibility to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field for instance at a boron neutron capture therapy (BNCT) facility. Tests with formates and dithionates of enriched 6Li and lithium compounds with natural composition have been performed at the BNCT facility at Studsvik, Sweden. Irradiations have been performed at 3 cm depth in a Perspex phantom in a fluence rate of thermal neutrons 1.8 x 10(9) n cm(-2) s(-1). The compounds were also irradiated in a pure X-ray field from a 4 MV linear accelerator at 5 cm depth in a phantom with accurately determined absorbed doses. The signal intensity and shape was investigated within 3 h after the irradiation. A single line spectrum attributed to the CO2- radical was observed after irradiation of lithium formate. An increase in line width occurring after neutron irradiation in comparison with photon irradiation of the Li-6 sample was attributed to dipolar broadening between CO2- radicals trapped in the tracks of the alpha particles. A spectrum due to the SO3- radical anion was observed after irradiation of lithium dithionate. The signal amplitude increased using the Li-6 in place of the Li with natural composition of isotopes, in studies with low energy X-ray irradiation. Due to the decreased line width, caused by the difference in g(N) and I between the isotopes, the sensitivity with Li-6 dithionate may be enhanced by an order of magnitude compared to alanine dosimetry. After comprehensive examination of the different combinations of compounds with different amounts of Li-6 and Li-7 regarding dosimetry, radiation chemistry and EPR properties these dosimeter material might be used for dose determinations at BNCT treatments and for biomedical experiments. Interesting properties of the radical formation might be visible due to the large difference in ionization density of neutrons compared to photons. (C) 2003 Elsevier B.V. All rights reserved.
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| 14. |
- Lund, Eva, et al.
(författare)
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Formates and dithionates : sensitive EPR-dosimeter materials for radiation therapy
- 2005
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Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 62:2, s. 317-324
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline, formates and dithionates are promising materials for EPR dosimetry, as large yields of radiation induced stable radicals are formed with a linear dose response. Rapid spin relaxation rates were detected in many of the substances, indicating that a high microwave power can be applied during EPR acquisition in order to improve sensitivity. Different techniques used to further improve the sensitivity, such as the replacement of Li-7 with Li-6 or exchange of protons with deuterons in the corresponding crystalline matrices and metal ion doping are discussed. It is concluded that formates and dithionates may be up to 10 times as sensitive as L-alpha-alanine. (C) 2004 Elsevier Ltd. All rights reserved.
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| 15. |
- Muthukumar, T., et al.
(författare)
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COLLAGEN AS A POTENTIAL BIOMATERIAL IN BIOMEDICAL APPLICATIONS
- 2018
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Ingår i: Reviews on Advanced Materials Science. - St Petersburg, Russian Federation : Rossiiskaya Akademiya Nauk * Institut Problem Mashinovedeniya. - 1606-5131 .- 1605-8127. ; 53:1, s. 29-39
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Tidskriftsartikel (refereegranskat)abstract
- Collagen, a biopolymer finds its application in the preparation of pharmaceutical products that are used in wound management, ophthalmic, orthopaedic and oral surgeries. This wide applicability is due its special properties such as biodegradability, biocompatibility, easy availability and high versatility. Collagen is isolated from various sources such as bovine skin, fish skin, chicken skin, skin waste of marine organisms, solid wastes of leather industry, short tendons of slaughtered cattle and bone. The isolated collagen from biological wastes is found to be cost effective due to the adaptation of simple methods for its isolation when compared with other commercially available biological macromolecules. The functional groups such as amino and carboxylic acid present in collagen helps in its modification that suits for various end uses which include wound healing, ophthalmic defects, drug delivery and tissue engineering applications. These beneficial properties impart uniqueness to collagen molecule among the available bio molecules.
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| 16. |
- Sastry, M, et al.
(författare)
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51V(n,β)52Cr reaction for neutron dosimetry : Development and assessment of a spectrophotometric method for determination of Cr in vanadium at sub ppm level
- 2004
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425 .- 1873-3557. ; 60:10, s. 2363-2367
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Tidskriftsartikel (refereegranskat)abstract
- With a view to monitoring the changes in coloration caused by the nuclear reaction 51V(n,β)52Cr in solution of vanadyl sulphate and using it for neutron dosimetry, electronic absorption spectra of vanadyl sulphate solutions were investigated at different concentrations of chromate impurity in micromolar range. It was observed that the presence of chromate enhances the absorptivity over a wide wavelength range serving essentially as a colouring agent for vanadium matrix, presumably due to charge transfer process. The absorbance at 380nm varied linearly over a wide concentration range. The limit of detection of chromate obtained is shown to be adequate for detecting neutron-induced chemical transmutation of vanadium to chromium under standard reactor conditions, when used with long path length cells. It was observed that the absorbance does not change on electron irradiation, suggesting that radiolytic effects due to beta decay, if any, do not interfere in the measurement of neutron-induced changes. In addition to its potential for neutron dosimetry, this is the first report of a simple and direct method of estimation of Cr in vanadium matrix at sub ppm level.
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| 17. |
- Sharma, L Ajitkumar, et al.
(författare)
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Molecular magnetic properties of two-copper(II) containing complexes [Cu(II) (1-phenylamidino-O-n-butylurea) en (H2O)(2)(2+) and [Cu(II) sulphato-mono (1-phenylamidino-O-methylurea)](2) - An EPR study
- 2004
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425 .- 1873-3557. ; 60:7, s. 1593-1600
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Tidskriftsartikel (refereegranskat)abstract
- Electron paramagnetic resonance (EPR) investigations were conducted on [Cu(II) (1-phenylamidino-O-n-butylurea) en (H2O)12 21 (1) and [Cu(II) sulphato-mono (1-phenylamidino-O-methylurea)](2) (2) respectively, in the temperature range 300-77 K. Fine structure characteristics of S = 1 system, was observed in both complexes with zero field splitting of 0.0525 and 0.0225 cm(-1), respectively, suggesting the formation of dimeric complexes. The presence of the half-field signal (DeltaM(s)= +/-2), in the complex 1, further confirmed the formation of dimer. The temperature dependence of EPR signal intensity has given evidence for the ferromagnetic (FM) coupling between the two Cu2+ ions. The isotropic exchange interaction constants J, were evaluated from this and were found out to be similar to57 and similar to27 cm(-1), respectively, for the complexes I and 2. The photoacoustic spectra of these complexes had shown a band around 26,400 cm(-1) characteristic of metal-metal bonding giving an independent support for the existence of dimeric Cu2+ species. The high magnetic moment values at room temperature for complex I (2.68mu(B)) and complex 2 (2.00mu(B)), obtained from the magnetic susceptibility measurements, support the formation of ferromagnetically coupled Cu2+ dimers.
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| 18. |
- Sharma, Suchinder, 1982, et al.
(författare)
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Understanding the Reasons for Variations in Luminescence Sensitivity of Natural Quartz Using Spectroscopic and Chemical Studies
- 2017
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Ingår i: Proceedings of the Indian National Science Academy. - : Indian National Science Academy. - 0370-0046. ; 83:3, s. 645-653
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Tidskriftsartikel (refereegranskat)abstract
- Natural quartz from diverse provenances exhibit variations in their luminescence sensitivity (photon flux/mg.Gy) that span over ten orders of magnitude. A range of factors (such as crystallization/recrystallization process, irradiation, thermal and optical history) that modify luminescence sensitivity have been considered to explain such differences in luminescence sensitivity. However, a clearly definable/identifiable reason is still awaited; such as, these large variations in luminescence sensitivity are related to commonly occurring luminescence quenchers/enhancers in natural quartz lattice. Towards this, quartz mineral grains extracts from different provenances and from varied depositional environments were examined spectroscopically using Fourier Transform infra-red spectroscopy (FTIR), optically stimulated luminescence (OSL), photoluminescence (PL), time resolved PL (TRPL) decay, thermoluminescence (TL) and the trace element analysis. The present study exhibited an anti-correlation between OSL sensitivity and water content in quartz (estimated through integrated intensity of normalized FTIR signal in the wave number region 3000-3600 cm(-1)), such that a sensitivity change of over 5 orders of magnitude corresponded to a change in integrated water absorption signal by 5 times, but in opposite direction. PL and TRPL results enabled further insights.
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| 19. |
- Siotia, Anjan, et al.
(författare)
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Utility of a whole blood single platelet counting assay to monitor the effects of tirofiban in patients with acute coronary syndromes scheduled for coronary intervention.
- 2006
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 95:6
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to establish the utility of a whole-blood single-platelet counting (WBSPC) assay, a measure of microaggregation, in monitoring the effects of tirofiban, comparing this with optical aggregometry (OA) and the Ultegra TRAP cartridge system (UTC), measures of macroaggregation. Fifty-nine patients with acute coronary syndrome scheduled for coronary angiography +/- angioplasty were studied. WBSPC assay (ADP 0.3-100 microM, Sysmex KX21 analyzer), OA (ADP 20 microM) and UTC were performed: before starting tirofiban; 30 min, 4 and 24 h after starting tirofiban; and 1 and 2 h after stopping tirofiban. Thirty minutes after starting tirofiban, there was substantial inhibition of platelet aggregation (40 +/- 30%; WBSPC, 2 minutes after addition of ADP 30 microM) and this remained stable at 4 and 24 h. OA (86 +/- 17%; inhibition of maximal aggregation, ADP 20 microM) and UTC (93 +/- 7%) showed marked inhibition with less inter-individual variation. There was no significant correlation between OA and UTC results (R(2) = 0.006), but fair correlation between OA and WBSPC results (R(2) = 0.37). Greater inhibition of macroaggregation (OA and UTC) was seen compared to microaggregation (WBSPC) such that WBSPC was more discriminating in the therapeutic range when macroaggregation was often completely inhibited. A WBSPC assay of platelet microaggregation shows promise for monitoring GPIIb/IIIa antagonists.
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