| 1. |
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| 2. |
- Huyghe, Jeroen R, et al.
(author)
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Genetic architectures of proximal and distal colorectal cancer are partly distinct
- 2021
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In: Gut. - : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 70:7, s. 1325-1334
-
Journal article (peer-reviewed)abstract
- Objective: An understanding of the etiologic heterogeneity of colorectal cancer (CRC) is critical for improving precision prevention, including individualized screening recommendations and the discovery of novel drug targets and repurposable drug candidates for chemoprevention. Known differences in molecular characteristics and environmental risk factors among tumors arising in different locations of the colorectum suggest partly distinct mechanisms of carcinogenesis. The extent to which the contribution of inherited genetic risk factors for CRC differs by anatomical subsite of the primary tumor has not been examined.Design: To identify new anatomical subsite-specific risk loci, we performed genome-wide association study (GWAS) meta-analyses including data of 48 214 CRC cases and 64 159 controls of European ancestry. We characterised effect heterogeneity at CRC risk loci using multinomial modelling.Results: We identified 13 loci that reached genome-wide significance (p<5×10-8) and that were not reported by previous GWASs for overall CRC risk. Multiple lines of evidence support candidate genes at several of these loci. We detected substantial heterogeneity between anatomical subsites. Just over half (61) of 109 known and new risk variants showed no evidence for heterogeneity. In contrast, 22 variants showed association with distal CRC (including rectal cancer), but no evidence for association or an attenuated association with proximal CRC. For two loci, there was strong evidence for effects confined to proximal colon cancer.Conclusion: Genetic architectures of proximal and distal CRC are partly distinct. Studies of risk factors and mechanisms of carcinogenesis, and precision prevention strategies should take into consideration the anatomical subsite of the tumour.
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| 3. |
- Speakman, John R., et al.
(author)
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Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure
- 2023
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In: Nature Metabolism. - : NATURE PORTFOLIO. - 2522-5812. ; 5:4, s. 579-588
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Journal article (other academic/artistic)abstract
- Obesity is caused by a prolonged positive energy balance(1,2). Whether reduced energy expenditure stemming from reduced activity levels contributes is debated(3,4). Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.
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| 4. |
- Welsh, Joshua A., et al.
(author)
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Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches
- 2024
-
In: Journal of Extracellular Vesicles. - : John Wiley and Sons Inc. - 2001-3078. ; 13:2
-
Journal article (peer-reviewed)abstract
- Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its ‘Minimal Information for Studies of Extracellular Vesicles’, which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.
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| 5. |
- Lin, Yen-Hung, et al.
(author)
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A piperidinium salt stabilizes efficient metal-halide perovskite solar cells
- 2020
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In: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 369:6499, s. 96-
-
Journal article (peer-reviewed)abstract
- Longevity has been a long-standing concern for hybrid perovskite photovoltaics. We demonstrate high-resilience positive-intrinsic-negative perovskite solar cells by incorporating a piperidinium-based ionic compound into the formamidinium-cesium lead-trihalide perovskite absorber. With the bandgap tuned to be well suited for perovskite-on-silicon tandem cells, this piperidinium additive enhances the open-circuit voltage and cell efficiency. This additive also retards compositional segregation into impurity phases and pinhole formation in the perovskite absorber layer during aggressive aging. Under full-spectrum simulated sunlight in ambient atmosphere, our unencapsulated and encapsulated cells retain 80 and 95% of their peak and post-burn-in efficiencies for 1010 and 1200 hours at 60 degrees and 85 degrees C, respectively. Our analysis reveals detailed degradation routes that contribute to the failure of aged cells.
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| 6. |
- Paolini, Lucia, et al.
(author)
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Large-scale production of extracellular vesicles: Report on the “massivEVs” ISEV workshop
- 2022
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In: Journal of Extracellular Biology. - : Wiley. - 2768-2811. ; 1:10
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Journal article (peer-reviewed)abstract
- Extracellular vesicles (EVs) large-scale production is a crucial point for the translation of EVs from discovery to application of EV-based products. In October 2021, the International Society for Extracellular Vesicles (ISEV), along with support by the FET-OPEN projects, “The Extracellular Vesicle Foundry” (evFOUNDRY) and “Extracellular vesicles from a natural source for tailor-made nanomaterials” (VES4US), organized a workshop entitled “massivEVs” to discuss the potential challenges for translation of EV-based products. This report gives an overview of the topics discussed during “massivEVs”, the most important points raised, and the points of consensus reached after discussion among academia and industry representatives. Overall, the review of the existing EV manufacturing, upscaling challenges and directions for their resolution highlighted in the workshop painted an optimistic future for the expanding EV field.
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| 7. |
- Sai, Hanna, et al.
(author)
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Observations of the very young Type Ia Supernova 2019np with early-excess emission
- 2022
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In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 514:3, s. 3541-3558
-
Journal article (peer-reviewed)abstract
- Early-time radiative signals from Type Ia supernovae (SNe Ia) can provide important constraints on the explosion mechanism and the progenitor system. We present observations and analysis of SN 2019np, a nearby SN Ia discovered within 1–2 days after the explosion. Follow-up observations were conducted in optical, ultraviolet, and near-infrared bands, covering the phases from ∼−16.7 d to ∼+ 367.8 d relative to its B-band peak luminosity. The photometric and spectral evolutions of SN 2019np resemble the average behaviour of normal SNe Ia. The absolute B-band peak magnitude and the post-peak decline rate are Mmax(B) = −19.52 ± 0.47 mag and Δm15(B) = 1.04 ± 0.04 mag, respectively. No Hydrogen line has been detected in the nebular-phase spectra of SN 2019np. Assuming that the 56Ni powering the light curve is centrally located, we find that the bolometric light curve of SN 2019np shows a flux excess up to 5.0 per cent in the early phase compared to the radiative diffusion model. Such an extra radiation perhaps suggests the presence of an additional energy source beyond the radioactive decay of central nickel. Comparing the observed colour evolution with that predicted by different models, such as interactions of SN ejecta with circumstellar matter (CSM)/companion star, a double-detonation explosion from a sub-Chandrasekhar mass white dwarf (WD) and surface 56Ni mixing, we propose that the nickel mixing is more favoured for SN 2019np.
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| 8. |
- Brunet-Ratnasingham, Elsa, et al.
(author)
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Sustained IFN signaling is associated with delayed development of SARS-CoV-2-specific immunity
- 2023
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Other publication (other academic/artistic)abstract
- Plasma RNAemia, delayed antibody responses and inflammation predict COVID-19 outcomes, but the mechanisms underlying these immunovirological patterns are poorly understood. We profile 782 longitudinal plasma samples from 318 hospitalized COVID-19 patients. Integrated analysis using k-means reveal four patient clusters in a discovery cohort: mechanically ventilated critically-ill cases are subdivided into good prognosis and high-fatality clusters (reproduced in a validation cohort), while non-critical survivors are delineated by high and low antibody responses. Only the high-fatality cluster is enriched for transcriptomic signatures associated with COVID-19 severity, and each cluster has distinct RBD-specific antibody elicitation kinetics. Both critical and non-critical clusters with delayed antibody responses exhibit sustained IFN signatures, which negatively correlate with contemporaneous RBD-specific IgG levels and absolute SARS-CoV-2-specific B and CD4+ T cell frequencies. These data suggest that the “Interferon paradox” previously described in murine LCMV models is operative in COVID-19, with excessive IFN signaling delaying development of adaptive virus-specific immunity.
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| 9. |
- Brunet-Ratnasingham, Elsa, et al.
(author)
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Sustained IFN signaling is associated with delayed development of SARS-CoV-2-specific immunity.
- 2024
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In: Nature Communications. - 2041-1723. ; 15:1, s. 4177-
-
Journal article (peer-reviewed)abstract
- Plasma RNAemia, delayed antibody responses and inflammation predict COVID-19 outcomes, but the mechanisms underlying these immunovirological patterns are poorly understood. We profile 782 longitudinal plasma samples from 318 hospitalized patients with COVID-19. Integrated analysis using k-means reveals four patient clusters in a discovery cohort: mechanically ventilated critically-ill cases are subdivided into good prognosis and high-fatality clusters (reproduced in a validation cohort), while non-critical survivors segregate into high and low early antibody responders. Only the high-fatality cluster is enriched for transcriptomic signatures associated with COVID-19 severity, and each cluster has distinct RBD-specific antibody elicitation kinetics. Both critical and non-critical clusters with delayed antibody responses exhibit sustained IFN signatures, which negatively correlate with contemporaneous RBD-specific IgG levels and absolute SARS-CoV-2-specific B and CD4+ T cell frequencies. These data suggest that the "Interferon paradox" previously described in murine LCMV models is operative in COVID-19, with excessive IFN signaling delaying development of adaptive virus-specific immunity.
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| 10. |
- Chen, Pan, et al.
(author)
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Small Angle Neutron Scattering Shows Nanoscale PMMA Distribution in Transparent Wood Biocomposites
- 2021
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 21:7, s. 2883-2890
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Journal article (peer-reviewed)abstract
- Transparent wood biocomposites based on PMMA combine high optical transmittance with excellent mechanical properties. One hypothesis is that despite poor miscibility the polymer is distributed at the nanoscale inside the cell wall. Small-angle neutron scattering (SANS) experiments are performed to test this hypothesis, using biocomposites based on deuterated PMMA and "contrast-matched" PMMA. The wood cell wall nanostructure soaked in heavy water is quantified in terms of the correlation distance d between the center of elementary cellulose fibrils. For wood/deuterated PMMA, this distance d is very similar as for wood/heavy water (correlation peaks at q approximate to 0.1 angstrom(-1)). The peak disappears when contrast-matched PMMA is used, indeed proving nanoscale polymer distribution in the cell wall. The specific processing method used for transparent wood explains the nanocomposite nature of the wood cell wall and can serve as a nanotechnology for cell wall impregnation of polymers in large wood biocomposite structures.
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| 11. |
- Drilon, Alexander, et al.
(author)
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Clinicopathologic Features and Response to Therapy of NRG1 Fusion-Driven Lung Cancers : The eNRGy1 Global Multicenter Registry
- 2021
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In: Journal of Clinical Oncology. - : LIPPINCOTT WILLIAMS & WILKINS. - 0732-183X .- 1527-7755. ; 39:25, s. 2791-2802
-
Journal article (peer-reviewed)abstract
- PURPOSE Although NRG1 fusions are oncogenic drivers across multiple tumor types including lung cancers, these are difficult to study because of their rarity. The global eNRGy1 registry was thus established to characterize NRG1 fusion-positive lung cancers in the largest and most diverse series to date. METHODS From June 2018 to February 2020, a consortium of 22 centers from nine countries in Europe, Asia, and the United States contributed data from patients with pathologically confirmed NRG1 fusion-positive lung cancers. Profiling included DNA-based and/or RNA-based next-generation sequencing and fluorescence in situ hybridization. Anonymized clinical, pathologic, molecular, and response (RECIST v1.1) data were centrally curated and analyzed. RESULTS Although the typified never smoking (57%), mucinous adenocarcinoma (57%), and nonmetastatic (71%) phenotype predominated in 110 patients with NRG1 fusion-positive lung cancer, further diversity, including in smoking history (43%) and histology (43% nonmucinous and 6% nonadenocarcinoma), was elucidated. RNA-based testing identified most fusions (74%). Molecularly, six (of 18) novel 5 ' partners, 20 unique epidermal growth factor domain-inclusive chimeric events, and heterogeneous 5 '/3 ' breakpoints were found. Platinum-doublet and taxane-based (post-platinum-doublet) chemotherapy achieved low objective response rates (ORRs 13% and 14%, respectively) and modest progression-free survival medians (PFS 5.8 and 4.0 months, respectively). Consistent with a low programmed death ligand-1 expressing (28%) and low tumor mutational burden (median: 0.9 mutations/megabase) immunophenotype, the activity of chemoimmunotherapy and single-agent immunotherapy was poor (ORR 0%/PFS 3.3 months and ORR 20%/PFS 3.6 months, respectively). Afatinib achieved an ORR of 25%, not contingent on fusion type, and a 2.8-month median PFS. CONCLUSION NRG1 fusion-positive lung cancers were molecularly, pathologically, and clinically more heterogeneous than previously recognized. The activity of cytotoxic, immune, and targeted therapies was disappointing. Further research examining NRG1-rearranged tumor biology is needed to develop new therapeutic strategies.
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| 12. |
- Heyland, Daren K., et al.
(author)
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A Randomized Trial of Enteral Glutamine for Treatment of Burn Injuries
- 2022
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In: New England Journal of Medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 387:11, s. 1001-1010
-
Journal article (peer-reviewed)abstract
- BACKGROUNDGlutamine is thought to have beneficial effects on the metabolic and stress response to severe injury. Clinical trials involving patients with burns and other critically ill patients have shown conflicting results regarding the benefits and risks of glutamine supplementation.METHODSIn a double-blind, randomized, placebo-controlled trial, we assigned patients with deep second-or third-degree burns (affecting >= 10% to >= 20% of total body-surface area, depending on age) within 72 hours after hospital admission to receive 0.5 g per kilogram of body weight per day of enterally delivered glutamine or placebo. Trial agents were given every 4 hours through a feeding tube or three or four times a day by mouth until 7 days after the last skin grafting procedure, discharge from the acute care unit, or 3 months after admission, whichever came first. The primary outcome was the time to discharge alive from the hospital, with data censored at 90 days. We calculated subdistribution hazard ratios for discharge alive, which took into account death as a competing risk.RESULTS A total of 1209 patients with severe burns (mean burn size, 33% of total body-surface area) underwent randomization, and 1200 were included in the analysis (596 patients in the glutamine group and 604 in the placebo group). The median time to discharge alive from the hospital was 40 days (interquartile range, 24 to 87) in the glutamine group and 38 days (interquartile range, 22 to 75) in the placebo group (subdistribution hazard ratio for discharge alive, 0.91; 95% confidence interval [CI], 0.80 to 1.04; P = 0.17). Mortality at 6 months was 17.2% in the glutamine group and 16.2% in the placebo group (hazard ratio for death, 1.06; 95% CI, 0.80 to 1.41). No substantial between-group differences in serious adverse events were observed.CONCLUSIONSIn patients with severe burns, supplemental glutamine did not reduce the time to discharge alive from the hospital.
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| 13. |
- Li, C. -Y, et al.
(author)
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Observation of inhomogeneous plasmonic field distribution in a nanocavity
- 2020
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In: Nature Nanotechnology. - : Nature Research. - 1748-3387 .- 1748-3395.
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Journal article (peer-reviewed)abstract
- The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres1–6. Plasmon-enhanced applications include advanced spectroscopies7–10, optomechanics11, optomagnetics12 and biosensing13–17. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.
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| 14. |
- Nilsson, Erik, 1975-, et al.
(author)
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Testosterone concentrations andoutcomes in hemodialysis patients of the EVOLVE trial
- 2023
-
In: Nephrology, Dialysis and Transplantation. - : Oxford University Press. - 0931-0509 .- 1460-2385. ; 38:6, s. 1519-1527
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Hypogonadism is common in end-stage kidney disease and may contribute to morbidity and mortality.METHODS: Using data from the randomized controlled EVOLVE trial of cinacalcet, we analyzed the associations of total testosterone, free testosterone, and sex-hormone binding globulin (SHBG) serum concentrations with mortality and major cardiovascular events in 1692 men and 1059 women receiving hemodialysis. We also describe the effect of cinacalcet treatment on serum concentrations of testosterone.RESULTS: Among men, lower serum free testosterone (OR 0.18 95%, CI 0.04-0.82, p = 0.026) and higher SHBG (OR 1.05 per 10 nmol/L, 95% CI 1.01-1.10, p = 0.012), but not total testosterone, were associated with higher risk of death or cardiovascular event. Only SHBG was associated with all-cause mortality (OR 1.07 per 10 nmol/L, 95% CI 1.02-1.12, p = 0.0073). Among women, neither total- or free testosterone, nor SHBG were associated with outcomes. We found no statistically significant effect of cinacalcet treatment on SHBG, free- or total testosterone.CONCLUSIONS: Lower free testosterone and higher SHBG in serum are associated with higher risk of death or cardiovascular event in men undergoing chronic hemodialysis.
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| 15. |
- Palacin, M. R., et al.
(author)
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Roadmap on multivalent batteries
- 2024
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In: JPhys Energy. - 2515-7655. ; 6:3
-
Research review (peer-reviewed)abstract
- Battery technologies based in multivalent charge carriers with ideally two or three electrons transferred per ion exchanged between the electrodes have large promises in raw performance numbers, most often expressed as high energy density, and are also ideally based on raw materials that are widely abundant and less expensive. Yet, these are still globally in their infancy, with some concepts (e.g. Mg metal) being more technologically mature. The challenges to address are derived on one side from the highly polarizing nature of multivalent ions when compared to single valent concepts such as Li+ or Na+ present in Li-ion or Na-ion batteries, and on the other, from the difficulties in achieving efficient metal plating/stripping (which remains the holy grail for lithium). Nonetheless, research performed to date has given some fruits and a clearer view of the challenges ahead. These include technological topics (production of thin and ductile metal foil anodes) but also chemical aspects (electrolytes with high conductivity enabling efficient plating/stripping) or high-capacity cathodes with suitable kinetics (better inorganic hosts for intercalation of such highly polarizable multivalent ions). This roadmap provides an extensive review by experts in the different technologies, which exhibit similarities but also striking differences, of the current state of the art in 2023 and the research directions and strategies currently underway to develop multivalent batteries. The aim is to provide an opinion with respect to the current challenges, potential bottlenecks, and also emerging opportunities for their practical deployment.
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| 16. |
- Saha, Udiptya, et al.
(author)
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Plasmonic Fiber Optic Absorbance Biosensor for MDR-Mtb detection using Padlock Probing
- 2022
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In: 2022 Workshop on Recent Advances in Photonics (WRAP 2022). - Piscataway, New Jersey : Institute of Electrical and Electronics Engineers (IEEE). - 9781665407038 ; , s. 170-171
-
Conference paper (peer-reviewed)abstract
- India is one among the 14 countries that have a high burden of Multidrug Resistant-Tuberculosis (MDR-TB), thereby demanding robust clinical and diagnostic attention. This study explores the development of a plasmonic fiber optic absorbance biosensor (P-FAB) for the detection of Rolling Circle Amplification (RCA) products to detect MDR genes of Mycobacterium tuberculosis. RCA is used as a nucleic acid amplification strategy for the specific and sensitive detection of DNA samples using the P-FAB platform. RCA-generated amplicons, when detected using U-bent optical fiber probe sensor with a nanoparticle-labeled DNA assay, provides adequate scope for the required clinical sensitivity towards multiplexed TB detection.
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| 17. |
- Sengar, Anjali, et al.
(author)
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Single-Virus Fusion Measurements Reveal Multiple Mechanistically Equivalent Pathways for SARS-CoV-2 Entry
- 2023
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In: Journal of Virology. - : American Society for Microbiology. - 0022-538X .- 1098-5514. ; 97:5
-
Journal article (peer-reviewed)abstract
- SARS-CoV-2 can use multiple pathways to infect cells, as demonstrated recently when new viral variants switched dominant infection pathways. Here, we used single-virus fusion experiments together with biochemical reconstitution to show that these multiple pathways coexist simultaneously and specifically that the virus can be activated by different proteases in different cellular compartments with mechanistically identical effects. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to cell surface receptors and is activated for membrane fusion and cell entry via proteolytic cleavage. Phenomenological data have shown that SARS-CoV-2 can be activated for entry at either the cell surface or in endosomes, but the relative roles in different cell types and mechanisms of entry have been debated. Here, we used single-virus fusion experiments and exogenously controlled proteases to probe activation directly. We found that plasma membrane and an appropriate protease are sufficient to support SARS-CoV-2 pseudovirus fusion. Furthermore, fusion kinetics of SARS-CoV-2 pseudoviruses are indistinguishable no matter which of a broad range of proteases is used to activate the virus. This suggests that the fusion mechanism is insensitive to protease identity or even whether activation occurs before or after receptor binding. These data support a model for opportunistic fusion by SARS-CoV-2 in which the subcellular location of entry likely depends on the differential activity of airway, cellsurface, and endosomal proteases, but all support infection. Inhibition of any single host protease may thus reduce infection in some cells but may be less clinically robust.IMPORTANCE SARS-CoV-2 can use multiple pathways to infect cells, as demonstrated recently when new viral variants switched dominant infection pathways. Here, we used single-virus fusion experiments together with biochemical reconstitution to show that these multiple pathways coexist simultaneously and specifically that the virus can be activated by different proteases in different cellular compartments with mechanistically identical effects. The consequences of this are that the virus is evolutionarily plastic and that therapies targeting viral entry should address multiple pathways at once to achieve optimal clinical effects.
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| 18. |
- Smulko, J., et al.
(author)
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Low-frequency noise in Au-decorated graphene-Si Schottky barrier diode at selected ambient gases
- 2023
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 122:21
-
Journal article (peer-reviewed)abstract
- We report results of the current-voltage characteristics and low-frequency noise in Au nanoparticle (AuNP)-decorated graphene-Si Schottky barrier diodes. Measurements were conducted in ambient air with addition of either of two organic vapors, tetrahydrofuran [(CH2)(4)O; THF] and chloroform (CHCl3), as also during yellow light illumination (592 nm), close to the measured particle plasmon polariton frequency of the Au nanoparticle layer. We observed a shift of the DC characteristics at forward voltages (forward resistance region) when tetrahydrofuran vapor was admitted (in a Au-decorated graphene-Si Schottky diode), and a tiny shift under yellow irradiation when chloroform was added (in not decorated graphene-Si Schottky diode). Significantly larger difference in the low-frequency noise was observed for the two gases during yellow light irradiation, compared with no illumination. The noise intensity was suppressed by AuNPs when compared with noise in graphene-Si Schottky diode without an AuNP layer. We conclude that flicker noise generated in the investigated Au-decorated Schottky diodes can be utilized for gas detection.
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| 19. |
- Subramanyam Thoota, Sai, et al.
(author)
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Site-specific millimeter-wave compressive channel estimation algorithms with hybrid MIMO architectures
- 2021
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In: ITU Journal on Future and Evolving Technologies. - : International Telecommunication Union. - 2616-8375. ; 2:4
-
Journal article (peer-reviewed)abstract
- In this paper, we present and compare three novel model-cum-data-driven channel estimation procedures in a millimeter-wave Multi-Input Multi-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system. The transceivers employ a hybrid analog-digital architecture. We adapt techniques from a wide range of signal processing methods, such as detection and estimation theories, compressed sensing, and Bayesian inference, to learn the unknown virtual beamspace domain dictionary, as well as the delay-and-beamspace sparse channel. We train the model-based algorithms with a site-specific training dataset generated using a realistic ray tracing-based wireless channel simulation tool. We assess the performance of the proposed channel estimation algorithms with the same site's test data. We benchmark the performance of our novel procedures in terms of normalized mean squared error against an existing fast greedy method and empirically show that model-based approaches combined with data-driven customization unanimously outperform the state-of-the-art techniques by a large margin. The proposed algorithms were selected as the top three solutions in the "ML5G-PHY Channel Estimation Global Challenge 2020" organized by the International Telecommunication Union.
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| 20. |
- Zou, Yatao, et al.
(author)
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Manipulating crystallization dynamics through chelating molecules for bright perovskite emitters
- 2021
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
-
Journal article (peer-reviewed)abstract
- Molecular additives are widely utilized to minimize non-radiative recombination in metal halide perovskite emitters due to their passivation effects from chemical bonds with ionic defects. However, a general and puzzling observation that can hardly be rationalized by passivation alone is that most of the molecular additives enabling high-efficiency perovskite light-emitting diodes (PeLEDs) are chelating (multidentate) molecules, while their respective monodentate counterparts receive limited attention. Here, we reveal the largely ignored yet critical role of the chelate effect on governing crystallization dynamics of perovskite emitters and mitigating trap-mediated non-radiative losses. Specifically, we discover that the chelate effect enhances lead-additive coordination affinity, enabling the formation of thermodynamically stable intermediate phases and inhibiting halide coordination-driven perovskite nucleation. The retarded perovskite nucleation and crystal growth are key to high crystal quality and thus efficient electroluminescence. Our work elucidates the full effects of molecular additives on PeLEDs by uncovering the chelate effect as an important feature within perovskite crystallization. As such, we open new prospects for the rationalized screening of highly effective molecular additives.
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