An 8‐week feeding trial was conducted to investigate the effects of dietary vitamin E on growth performance and antioxidant status of juvenile snakehead. The snakeheads (20.47 ± 0.06 g) were fed with ...five isonitrogenous and isoenergetic experimental diets that contained 13 (the basal diet), 52, 79, 168 and 326 mg of vitamin E kg−1, respectively. The maximum specific growth rate (SGR) and feed intake (FI) were achieved in fish fed on a diet with 79 mg kg−1 vitamin E (p < .05). No significant differences were found in protein efficiency ratio (PER), feed conversion ratio (FCR) and survival of fish among all groups (p > .05). Vitamin E supplementation improved hepatic glutathione peroxidase (GPx) activity significantly. A consistent decline in the hepatic and serum malondialdehyde (MDA) content was observed in fish fed diets with the increased supplementation of vitamin E (p < .05). In addition, with the increasing level of vitamin E, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were reduced (p < .05). However, serum superoxide dismutase (SOD), catalase (CAT) and alkaline phosphatase (ALP) activities were enhanced in fish fed 79 mg vitamin E kg−1 diet and then decreased significantly as the content of vitamin E in the diet increased (p < .05). Meanwhile, serum albumin (ALB) and globulin (GLB) were not affected by the supplemental levels of dietary vitamin E (p > .05). The vitamin E concentrations in liver and serum increased significantly with increasing dietary vitamin E (p < .05). Based on the broken‐line regression of SGR, vitamin E level in the diet is estimated to be 80.5 mg kg−1 for Channa argus × Channa maculata. In conclusion, this study indicated that the dietary appropriate vitamin E could enhance the growth performance, antioxidant status and non‐specific immune response.
Understanding the impact of age on vaccinations is essential for the design and delivery of vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis of multiple ...compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of the Delta and Omicron variants is less efficient than that of the ancestral Wuhan strain. Age-stratified analyses identify a group of low antibody responders where individuals ≥60 years are overrepresented. Waning of the antibody and cellular responses is observed in 30% of the vaccinees after 6 months. However, age does not influence the waning of these responses. Taken together, while individuals ≥60 years old take longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at 6 months post-vaccination. A third dose strongly boosts the low antibody responses in the older individuals against the ancestral Wuhan strain, Delta and Omicron variants.
The SARS‐CoV‐2 Delta (B.1.617.2) variant is capable of infecting vaccinated persons. An open question remains as to whether deficiencies in specific vaccine‐elicited immune responses result in ...susceptibility to vaccine breakthrough infection. We investigated 55 vaccine breakthrough infection cases (mostly Delta) in Singapore, comparing them against 86 vaccinated close contacts who did not contract infection. Vaccine breakthrough cases showed lower memory B cell frequencies against SARS‐CoV‐2 receptor‐binding domain (RBD). Compared to plasma antibodies, antibodies secreted by memory B cells retained a higher fraction of neutralizing properties against the Delta variant. Inflammatory cytokines including IL‐1β and TNF were lower in vaccine breakthrough infections than primary infection of similar disease severity, underscoring the usefulness of vaccination in preventing inflammation. This report highlights the importance of memory B cells against vaccine breakthrough and suggests that lower memory B cell levels may be a correlate of risk for Delta vaccine breakthrough infection.
Synopsis
This study compares the immune characteristics of 55 patients with vaccine breakthrough SARS‐CoV‐2 infection and 86 uninfected vaccinated close contacts. Memory B cell levels differed between the groups, identifying them as potential immune correlates of protection in Delta vaccine breakthrough.
Antibody levels, including neutralizing antibodies, were similar in vaccine breakthrough patients and close contacts.
Memory B cell levels, as assessed by B cell ELISpot, were lower in vaccine breakthrough patients than close contacts.
T cell profiles were broadly similar across vaccine breakthrough patients and close contacts.
The cytokine profile of vaccine breakthrough patients was similar to uninfected vaccinated individuals, with lower inflammatory profile compared to unvaccinated individuals with primary infection.
This study compares the immune characteristics of 55 patients with vaccine breakthrough SARS‐CoV‐2 infection and 86 uninfected vaccinated close contacts. Memory B cell levels differed between the groups, identifying them as potential immune correlates of protection in Delta vaccine breakthrough.
The detector system of the Daya Bay reactor neutrino experiment An, F.P.; Chan, W.T.; Chasman, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2016, Volume:
811
Journal Article
Peer reviewed
Open access
The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent ...data has provided the world׳s most precise measurement of sin22θ13 and the effective mass splitting Δmee2. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world׳s most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes, the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors’ baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking.
•The oxidation of the NiCoCr meduim-entropy alloy was studied in various oxygen pressures at 800 °C.•The oxidation kinetics of the alloy obeyed the parabolic-rate law.•The oxidation mechanism of the ...alloy was due to outward cation diffusion.•The main diffusing species were doubly- and triply-ionized cation vacancies.
The oxidation behavior of NiCoCr medium-entropy alloy was investigated at 800 °C in various oxygen pressures from 10 to 105 Pa. The results showed that the oxidation kinetics of NiCoCr followed the parabolic rate law, regardless of oxygen pressure. The oxidation rate constants of the alloy steadily increased with increasing oxygen pressure. The oxidation mechanism of the MEA was mainly controlled by outward cation diffusion to form an exclusive Cr2O3 layer although minor amounts of Co- or Ni-Cr spinels were observed at PO2 = 105 Pa under TEM analyses. The main diffusing species were doubly- and triply-ionized cation vacancies.
The development of ultrafast gas electron diffraction with nonrelativistic electrons has enabled the determination of molecular structures with atomic spatial resolution. It has, however, been ...challenging to break the picosecond temporal resolution barrier and achieve the goal that has long been envisioned—making space- and-time resolved molecular movies of chemical reaction in the gas-phase. Recently, an ultrafast electron diffraction (UED) apparatus using mega-electron-volt (MeV) electrons was developed at the SLAC National Accelerator Laboratory for imaging ultrafast structural dynamics of molecules in the gas phase. The SLAC gas-phase MeV UED has achieved 65 fs root mean square temporal resolution, 0.63 Å spatial resolution, and 0.22 Å−1 reciprocal-space resolution. Such high spatial-temporal resolution has enabled the capturing of real-time molecular movies of fundamental photochemical mechanisms, such as chemical bond breaking, ring opening, and a nuclear wave packet crossing a conical intersection. In this paper, the design that enables the high spatial-temporal resolution of the SLAC gas phase MeV UED is presented. The compact design of the differential pump section of the SLAC gas phase MeV UED realized five orders-of-magnitude vacuum isolation between the electron source and gas sample chamber. The spatial resolution, temporal resolution, and long-term stability of the apparatus are systematically characterized.
Abstract Global freshwater resources are vital to humanity and Earth’s ecosystems, yet about one third of the global population is affected by water scarcity for at least one month per year. In these ...areas, the overuse of freshwater resources can lead to the threat of depletion, marking them as the global ‘water scarcity hotspots’. This study combines outputs from a global hydrological model (PCR-GLOBWB 2) with an extensive literature search to provide a comprehensive intercomparison of the key drivers, pressures, states, impacts and responses (DPSIR) that shape the water gap between water demand and availability at the most important water scarcity hotspots worldwide. Hydroclimatic change, population growth, and water use for the industrial, municipal and agricultural sectors are the most important driving and pressuring forces on the water gap, affecting both water quality and quantity. These drivers and pressures have been showing increasing trends at all hotspots, which is concerning for the future development of the water gap. Additionally, we identify and characterize seven clusters of hotspots based on shared DPSIR patterns, revealing their common mechanisms. Our work highlights the diversity of water scarcity related issues at hotspots, especially the variety of impacts involved and governmental responses in place. The results of our DPSIR analysis provide valuable insights for building causal networks representing water gap dynamics at the hotspots. They form a foundation for conceptual models that illuminate human-water interactions, trade-offs, and synergies at the hotspots, while guiding policymakers in addressing the multifaceted challenge of closing the water gap.
Studies have found different waning rates of neutralising antibodies compared with binding antibodies against SARS-CoV-2. The impact of neutralising antibody waning rate at the individual patient ...level on the longevity of immunity remains unknown. We aimed to investigate the peak levels and dynamics of neutralising antibody waning and IgG avidity maturation over time, and correlate this with clinical parameters, cytokines, and T-cell responses.
We did a longitudinal study of patients who had recovered from COVID-19 up to day 180 post-symptom onset by monitoring changes in neutralising antibody levels using a previously validated surrogate virus neutralisation test. Changes in antibody avidities and other immune markers at different convalescent stages were determined and correlated with clinical features. Using a machine learning algorithm, temporal change in neutralising antibody levels was classified into five groups and used to predict the longevity of neutralising antibody-mediated immunity.
We approached 517 patients for participation in the study, of whom 288 consented for outpatient follow-up and collection of serial blood samples. 164 patients were followed up and had adequate blood samples collected for analysis, with a total of 546 serum samples collected, including 128 blood samples taken up to 180 days post-symptom onset. We identified five distinctive patterns of neutralising antibody dynamics as follows: negative, individuals who did not, at our intervals of sampling, develop neutralising antibodies at the 30% inhibition level (19 12% of 164 patients); rapid waning, individuals who had varying levels of neutralising antibodies from around 20 days after symptom onset, but seroreverted in less than 180 days (44 27% of 164 patients); slow waning, individuals who remained neutralising antibody-positive at 180 days post-symptom onset (46 28% of 164 patients); persistent, although with varying peak neutralising antibody levels, these individuals had minimal neutralising antibody decay (52 32% of 164 patients); and delayed response, a small group that showed an unexpected increase of neutralising antibodies during late convalescence (at 90 or 180 days after symptom onset; three 2% of 164 patients). Persistence of neutralising antibodies was associated with disease severity and sustained level of pro-inflammatory cytokines, chemokines, and growth factors. By contrast, T-cell responses were similar among the different neutralising antibody dynamics groups. On the basis of the different decay dynamics, we established a prediction algorithm that revealed a wide range of neutralising antibody longevity, varying from around 40 days to many decades.
Neutralising antibody response dynamics in patients who have recovered from COVID-19 vary greatly, and prediction of immune longevity can only be accurately determined at the individual level. Our findings emphasise the importance of public health and social measures in the ongoing pandemic outbreak response, and might have implications for longevity of immunity after vaccination.
National Medical Research Council, Biomedical Research Council, and A*STAR, Singapore.
We report the discovery of a gravitationally lensed hyperluminous infrared galaxy (intrinsic L
IR ≈ 1013 L⊙) with strong radio emission (intrinsic L
1.4 GHz ≈ 1025 W Hz−1) at z = 2.553. The source ...was identified in the citizen science project Space Warps through the visual inspection of tens of thousands of iJK
s colour composite images of luminous red galaxies (LRGs), groups and clusters of galaxies and quasars. Appearing as a partial Einstein ring (r
e
≈ 3 arcsec) around an LRG at z = 0.2, the galaxy is extremely bright in the sub-millimetre for a cosmological source, with the thermal dust emission approaching 1 Jy at peak. The redshift of the lensed galaxy is determined through the detection of the CO(3→2) molecular emission line with the Large Millimetre Telescope's Redshift Search Receiver and through O iii and Hα line detections in the near-infrared from Subaru/Infrared Camera and Spectrograph. We have resolved the radio emission with high-resolution (300–400 mas) eMERLIN L-band and Very Large Array C-band imaging. These observations are used in combination with the near-infrared imaging to construct a lens model, which indicates a lensing magnification of μ ≈ 10. The source reconstruction appears to support a radio morphology comprised of a compact (<250 pc) core and more extended component, perhaps indicative of an active nucleus and jet or lobe.
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