243 research outputs found
Electrochemical CO₂ Reduction to CO Catalyzed by 2D Nanostructures
Electrochemical CO₂ reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO₂ reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO₂ reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO₂ reduction into CO
Switching of the topologically trivial and non-trivial quantum phase transitions in compressed 1T-TiTe2: Experiments and Theory
We report the structural, vibrational and electrical transport properties up
to 16 GPa of the 1T-TiTe2, a prominent layered 2D system, which is predicted to
show a series of topologically trivial - nontrivial transitions under
hydrostatic compression. We clearly show signatures of two iso-structural
transition at 2 GPa and 4 GPa obtained from the minima in c/a ratio concomitant
with the phonon linewidth anomalies of Eg and A1g modes at around the same
pressures, providing strong indication of unusual electron-phonon coupling
associated to these transitions. Resistivity presents nonlinear behavior over
similar pressure ranges providing a strong indication of the electronic origin
of these pressure driven isostructural transitions. Our data thus provide clear
evidences of topological changes at A and L point of the Brillouin zone
predicted to be present in the compressed 1T-TiTe2. Between 4 GPa and 8 GPa,
the c/a ratio shows a plateau suggesting a transformation from an anisotropic
2D layer to a quasi 3D crystal network. First principles calculations suggest
that the 2D to quasi 3D evolution without any structural phase transitions is
mainly due to the increased interlayer Te-Te interactions (bridging) via the
charge density overlap. In addition to the pressure dependent isostructural
phase transitions, our data also evidences the occurrence of a first order
structural phase transition from the trigonal (P-3m1) phase at higher
pressures. We estimate the start of this structural phase transition to be 8
GPa and the symmetric of the new high-pressure phase to be monoclinic (C2/m).Comment: 22 pages, 11 Figures, 2 Table
Electrochemical CO₂ Reduction to CO Catalyzed by 2D Nanostructures
Electrochemical CO₂ reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO₂ reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO₂ reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO₂ reduction into CO
Missense mutations near the N-glycosylation site of the A2 domain lead to various intracellular trafficking defects in coagulation factor VIII
Citation: Wei, W., Zheng, C. L., Zhu, M., Zhu, X. F., Yang, R. C., Misra, S., & Zhang, B. (2017). Missense mutations near the N-glycosylation site of the A2 domain lead to various intracellular trafficking defects in coagulation factor VIII. Scientific Reports, 7, 14. doi:10.1038/srep45033Missense mutation is the most common mutation type in hemophilia. However, the majority of missense mutations remain uncharacterized. Here we characterize how hemophilia mutations near the unused N-glycosylation site of the A2 domain (N582) of FVIII affect protein conformation and intracellular trafficking. N582 is located in the middle of a short 3(10)-helical turn (D580-S584), in which most amino acids have multiple hemophilia mutations. All 14 missense mutations found in this 3(10)-helix reduced secretion levels of the A2 domain and full-length FVIII. Secreted mutants have decreased activities relative to WT FVIII. Selected mutations also lead to partial glycosylation of N582, suggesting that rapid folding of local conformation prevents glycosylation of this site in wild-type FVIII. Protease sensitivity, stability and degradation of the A2 domain vary among mutants, and between non-glycosylated and glycosylated species of the same mutant. Most of the mutants interact with the ER chaperone BiP, while only mutants with aberrant glycosylation interact with calreticulin. Our results show that the short 3(10)-helix from D580 to S584 is critical for proper biogenesis of the A2 domain and FVIII, and reveal a range of molecular mechanisms by which FVIII missense mutations lead to moderate to severe hemophilia A
Unveiling vaccine safety: a narrative review of pharmacovigilance in India's COVID-19 vaccination
In India, a robust vaccine pharmacovigilance system is essential to the effective implementation of COVID-19 immunization programs, ensuring the safety and efficacy of the administered vaccines. The National Expert Group on Vaccine Administration for COVID-19 and the Pharmacovigilance Programme of India have played vital roles in monitoring and analyzing adverse events following immunization (AEFI). These tools have made it easier to gather, assess, and report information about different adverse drug reactions connected to COVID-19 vaccines. However, there are several issues with India's vaccination pharmacovigilance, including underreporting and sluggish data gathering. To improve the efficiency of the pharmacovigilance system, it is crucial to address these issues and encourage active reporting by healthcare professionals and the general public. This insightful review article serves as a critical resource for shedding light on India's vaccine pharmacovigilance efforts throughout the COVID-19 vaccination drive. It also elucidates how these efforts are pivotal in bolstering public confidence in vaccines. The comprehensive coverage of reported AEFI not only showcases the commitment to vaccine safety but also helps healthcare professionals and policymakers make informed decisions to enhance the overall vaccination program
Software Defined Multi-Spectral Imaging for Arctic Sensor Networks
Availability of off-the-shelf infrared sensors combined with high definition visible cameras has made possible the construction of a Software Defined Multi-Spectral Imager (SDMSI) combining long-wave, near-infrared and visible imaging. The SDMSI requires a real-time embedded processor to fuse images and to create real-time depth maps for opportunistic uplink in sensor networks. Researchers at Embry Riddle Aeronautical University working with University of Alaska Anchorage at the Arctic Domain Awareness Center and the University of Colorado Boulder have built several versions of a low-cost drop-in-place SDMSI to test alternatives for power efficient image fusion. The SDMSI is intended for use in field applications including marine security, search and rescue operations and environmental surveys in the Arctic region. Based on Arctic marine sensor network mission goals, the team has designed the SDMSI to include features to rank images based on saliency and to provide on camera fusion and depth mapping. A major challenge has been the design of the camera computing system to operate within a 10 to 20 Watt power budget. This paper presents a power analysis of three options: 1) multi-core, 2) field programmable gate array with multi-core, and 3) graphics processing units with multi-core. For each test, power consumed for common fusion workloads has been measured at a range of frame rates and resolutions. Detailed analyses from our power efficiency comparison for workloads specific to stereo depth mapping and sensor fusion are summarized. Preliminary mission feasibility results from testing with off-the-shelf long-wave infrared and visible cameras in Alaska and Arizona are also summarized to demonstrate the value of the SDMSI for applications such as ice tracking, ocean color, soil moisture, animal and marine vessel detection and tracking. The goal is to select the most power efficient solution for the SDMSI for use on UAVs (Unoccupied Aerial Vehicles) and other drop-in-place installations in the Arctic. The prototype selected will be field tested in Alaska in the summer of 2016
KELT-10b: The First Transiting Exoplanet from the KELT-South Survey -- A Hot Sub-Jupiter Transiting a V = 10.7 Early G-Star
We report the discovery of KELT-10b, the first transiting exoplanet
discovered using the KELT-South telescope. KELT-10b is a highly inflated
sub-Jupiter mass planet transiting a relatively bright star (TYC
8378-64-1), with T = K, =
and [Fe/H] = , an inferred mass
M = M and radius R =
R. The planet has a radius R =
R and mass M =
M. The planet has an eccentricity consistent with zero and a semi-major
axis = AU. The best fitting linear
ephemeris is = 2457066.720450.00027 BJD and P =
4.16627390.0000063 days. This planet joins a group of highly inflated
transiting exoplanets with a radius much larger and a mass much less than those
of Jupiter. The planet, which boasts deep transits of 1.4%, has a relatively
high equilibrium temperature of T = K, assuming zero
albedo and perfect heat redistribution. KELT-10b receives an estimated
insolation of 10 erg s cm,
which places it far above the insolation threshold above which hot Jupiters
exhibit increasing amounts of radius inflation. Evolutionary analysis of the
host star suggests that KELT-10b is unlikely to survive beyond the current
subgiant phase, due to a concomitant in-spiral of the planet over the next
1 Gyr. The planet transits a relatively bright star and exhibits the
third largest transit depth of all transiting exoplanets with V 11 in the
southern hemisphere, making it a promising candidate for future atmospheric
characterization studies.Comment: 20 pages, 13 figures, 7 tables, accepted for publication in MNRA
Association between neutrophil to lymphocyte ratio with the severity of coronary artery diseases
Background: Coronary artery disease is a type of heart disease where the arteries of the heart cannot deliver enough oxygen-rich blood to the heart. This study aimed to evaluate the association between neutrophil to lymphocyte ratio (NLR) with the severity of coronary artery diseases.
Methods: This cross-sectional study was conducted in the Department of Cardiology, Chittagong Medical College Hospital, Chattogram, Bangladesh during the period from 1 July 2020 to 31 June 2021. 160 patients undergoing elective coronary angiography with the symptoms of coronary artery disease were enrolled in this study. A purposive sampling technic was used. The association between NLR and Gensini score was assessed using Pearson’s or Spearman’s correlation analysis as appropriate. All data were processed, analyzed and disseminated by using MS Excel and SPSS version 23.0 program as per necessity.
Results: The mean (±SD) Gensini score of our participants was 42.75 (±29.50) and the mean (±SD) NLR (Neutrophil-lymphocyte ratio) was 2.38 (±1.11). In this study, the AUROC for NLR was found as 0.851 with a P-value of <0.001, indicating a statistically significant association of NLR with the severity of CAD. The scatter dot diagram showed the correlation between NLR and Gensini score. Both the variables were positively correlated and the degree of correlation was found statistically significant (r=0.44; p<0.001) by Pearson’s correlation test. The multivariate logistic regression analysis showed that a high level of NLR had an independent association with severe CAD (with OR being 3.308) along with dyslipidemia.
Conclusion: High blood NLR is associated with the severity of CAD and it may be useful for predicting angiographically severe disease
KELT-3b: A Hot Jupiter Transiting A V=9.8 Late-F Star
We report the discovery of KELT-3b, a moderately inflated transiting hot Jupiter with a mass of 1.477(-0.067)(+0.066) M-J, radius of 1.345 +/- 0.072 R-J, and an orbital period of 2.7033904 +/- 0.000010 days. The host star, KELT-3, is a V = 9.8 late F star with M-* = 1.278(-0.061)(+0.063) M-circle dot, R-* = 1.472(-0.067)(+0.065) R-circle dot, T-eff = 6306(-49)(+50) K, log(g) = 4.209(-0.031)(+0.033), and [Fe/H] = 0.044(-0.082)(+0.080), and has a likely proper motion companion. KELT-3b is the third transiting exoplanet discovered by the KELT survey, and is orbiting one of the 20 brightest known transiting planet host stars, making it a promising candidate for detailed characterization studies. Although we infer that KELT-3 is significantly evolved, a preliminary analysis of the stellar and orbital evolution of the system suggests that the planet has likely always received a level of incident flux above the empirically identified threshold for radius inflation suggested by Demory & Seager
Electrochemical CO2 Reduction to CO Catalyzed by 2D Nanostructures
Electrochemical CO2 reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO2 reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO2 reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO2 reduction into CO. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.1
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