construction of the Schottky-junction is considered to be a valid route to boost the spatial charge separation and transfer of the photocatalytic system. Herein, two-dimensional (2D) O-doped g-C3N4 ...nanosheets were prepared by an annealing route, and then a 2D/2D Ti3C2 MXene/O-doped g-C3N4 Schottky-junction was fabricated using an in-situ electrostatic assembly of negatively charged Ti3C2 MXene and positively charged O-doped g-C3N4 nanosheets. The as-prepared Ti3C2 MXene/O-doped g-C3N4 Schottky-junction exhibited almost two times enhanced hydrogen evolution (25124 μmol/g/h) in comparison to pristine O-doped g-C3N4 (13745 μmol/g/h) and Ti3C2 MXene/pristine C3N4 (15573 μmol/g/h). Based on fully characterizations and theory calculation, the enhanced photocatalytic performance could be attributed to the synergy effect of intimate 2D/2D interfacial contact and the construction of Schottky-junction, which result in the short charge transport distance from HCN to Ti3C2 MXene and efficient separation of the photo-generated charge. This study will provide new insight into developing 2D/2D Schottky-junction photocatalysts for the solution of the energy crisis.
Abstract Inverse vulcanization exploits S 8 to synthesize polysulfides. However, evolution of products and its mechanism during inverse vulcanization remains elusive. Herein, inverse vulcanization ...curves are obtained to describe the inverse vulcanization process in terms of three stages: induction, curing and over-cure. The typical curves exhibit a moduli increment before declining or plateauing, reflecting the process of polysulfide network formation and loosing depending on monomers. For aromatic alkenes, in the over-cure, the crosslinked polysulfide evolves significantly into a sparse network with accelerated relaxation, due to the degradation of alkenyl moieties into thiocarbonyls. The inverse vulcanization product of olefins degrades slowly with fluctuated relaxation time and modulus because of the generation of thiophene moieties, while the inverse vulcanization curve of dicyclopentadiene has a plateau following curing stage. Confirmed by calculations, the mechanisms reveal the alkenyl groups react spontaneously into thiocarbonyls or thiophenes via similar sulfur-substituted alkenyl intermediates but with different energy barriers.
PCR-based DNA amplification has been one of the major methods in aquaculture research for decades, although its use outside the modern laboratory environment is limited due to the relatively complex ...methods and high costs. To this end, we investigated a swabbing and disc protocol for the collection of DNA samples from fish which could extract DNA from fish skin mucus by a non-invasion technique costing only $0.02 (USD) and requiring less than 30 seconds. The disc method that we chose could use the cheap filter paper to extract DNA from above 10
crucian carp blood cells, which is comparable to the commercial kit. By using skin mucus swabbing and the disc method, we can obtain amplification-ready DNA from mucus to distinguish different species from our smallest fish (medaka, ~2.5 cm and crucian carp, ~7 cm) to our biggest fish (tilapia, ~15 cm). Furthermore, the viral pathogen
herpesvirus (CaHV) of crucian carp was detected using our method, which would make performing molecular diagnostic assays achievable in limited-resource settings including aquafarms and aqua stores outside the laboratory environment.
Graphitic carbon nitride (g-C3N4) is sprouted as an efficient and cost-effective visible-light-responsive photocatalyst for yielding hydrogen from water splitting. However, a brisk recombination of ...light-induced electron-hole (e− - h+) pairs in the bulk g-C3N4 effectuate poor quantum efficiency in the hydrogen evolution reaction (HER). The shuttle redox mediator manifests ample potential in accelerating photo-induced carrier segregation and in boosting charge transport in the HER. Here, we report that exploiting Ag/Ag(I) and Fe(III)/Fe(II) shuttle redox mediators, the hydrogen-evolving rate of the aforementioned g-C3N4 nanosheets can reach 3213.3 μmol g−1 h−1 under visible-light irradiation, which is eight times higher than that of pure g-C3N4 (404.82 μmol g−1 h−1). The effective coupling between a hydrogen-evolving catalyst and appropriate shuttle redox mediators significantly improves the HER-photocatalytic performance of native g-C3N4 nanosheets. Density functional theory calculations show that the presence of Ag/Ag(I) and Fe(III)/Fe(II) shuttle redox mediators can effectively promote H atom adsorption and facilitate a H2O reduction reaction. This work envisages a new and deft approach for contriving high-performance g–C3N4–based photocatalysts for highly efficient solar-to-fuel conversion.
•Ag/Ag(I) and Fe(III)/Fe(II) shuttle redox were loaded on the surface of g-C3N4.•The modified g-C3N4 showed excellent photocatalytic H2 activity and chemical stability.•Double shuttle redox on the g-C3N4 boost the separation of photoexcited charges.
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•Polysulfide elastomers (SOA) crosslinked by soybean oil and allyl glyceryl ether.•Dynamic bonds and epoxides grant SOA excellent processability and ...compatibilization.•Polysulfides-toughened PLA with preserved strength firstly reported.•Internal cavitation of tougheners significantly improved the toughening effect.•The toughened blend exhibited outstanding broad-spectrum antimicrobial.
The toughening of PLA is usually realized by blending with elastomers or plasticizers, but often conflicted with lowered mechanical strength and complicated preparation steps. In the current study, inverse vulcanization was used to synthesize a series of dynamically cross-linked polysulfide (SOA) elastomers based on refining by-product elemental sulfur, soybean oil (SO) and allyl glyceryl ether (AGE), which provides dynamically reversible S-S bonds, flexible triglyceride segments and reactive epoxy functions.
Melt blended with PLA, the SOAs exhibit great toughening effects and produce droplet-matrix typed blends with good interfacial compatibilization verified by rheology. SOA composition was decisive in dictating toughening efficiency. A high AGE content induces self-polymerization of epoxy groups, resulting in dominance of permanent crosslinking in SOA, giving rise to rigid SOA particles with bad processability and dispersity in PLA, hence poor toughener cavitations under external forces with unsatisfying toughening effect. A high sulfur and low AGE content results in dominance of dynamic crosslinking, providing soft SOA particles in favor of processing and dispersion in PLA matrix with small domains and thin ligament thickness, thus favoring internal cavitation of SOA particles to achieve good toughness. However, the presence of unreacted sulfur with a too high sulfur content can mitigate the toughening effect. In particular, a highly toughened blend with optimized SOA composition (PLA-S50O25A25) was obtained with excellent toughness (elongation at break 235.7% and tensile toughness 76.5 MJ/m3) balanced by only slightly impaired strength (tensile strength 50–60 MPa and modulus ∼ 900 Mpa). Moreover, the PLA-SOA exhibits excellent broad-spectrum anti-bacterial effects. This study reported the unprecedented use of fully sustainable dynamically-crosslinked elastomers as tougheners of PLA, paving new ways for PLA modification with balanced stiffness-toughness and antibacterial activity.
Employing co-catalysts to develop high efficiency photocatalytic materials are a promising solution to improve solar oxygen evolution, especially designing a novel multi-cocatalyst combined ...heterojunction with synergetic effects between different components. Herein, one dimensional carbon nanotubes (CNTs) and two dimensional molybdenum disulfide (MoS2) as dual co-catalysts modified Ag3PO4 photocatalysts were prepared employing an in-situ co-corporation method. The resulting CNTs/MoS2/Ag3PO4 ternary nanocomposite showed 3 and 5-folds increased photocatalytic oxygen evolution activity compared to their binary CNTs/Ag3PO4 and MoS2/Ag3PO4 composites under LED irradiation, indicating the great potential of synergistic effect of dual co-catalysts in constructing high performance photocatalysts. The introduction of CNTs and MoS2 dual cocatalysts can encourage the separation of the photogenerated charge carriers more effectively compared with single cocatalyst, consequently improving the photocatalytic oxygen evolution activity. Our results have demonstrated an approach worthy for the design and production of high effectiveness photocatalyst system employing cocatalyst for water splitting.
Naturally abundant transition metal oxides with high theoretical capacity have attracted more attention than commercial graphite for use as anodes in lithium-ion batteries. Lithium-ion battery ...electrodes that exhibit excellent electrochemical performance can be efficiently achieved via three-dimensional （3D） architectures decorated with conductive polymers and carbon. As such, we developed 3D carbon-supported amorphous vanadium oxide microspheres and crystalline V203 microspheres via a facile solvothermal method. Both samples were assembled with ultrathin nanosheets, which consisted of uniformly distributed vanadium oxides and carbon. The formation processes were clearly revealed through a series of time-dependent experiments. These microspheres have numerous active reaction sites, high electronic conductivity, and excellent structural stability, which are all far superior to those of other lithium-ion battery anodes. More importantly, 95% of the second-cycle discharge capacity was retained after the amorphous microspheres were subjected to 7,000 cycles at a high rate of 2,000 mA/g. The crystalline microspheres also exhibited a high-rate and long-life performance, as evidenced by a 98% retention of the second-cycle discharge capacity after 9,000 cycles at a rate of 2,000 mA/g. Therefore, this facile solvothermal method as well as unique carbon-supported and nanosheet-assembled microspheres have significant potential for the synthesis of and use in, respectively, lithium-ion batteries.
Genome-wide association studies (GWAS) have identified many genetic loci associated with complex traits and diseases in the past 20 years. Multiple heritable covariates may be added into GWAS ...regression models to estimate direct effects of genetic variants on a focal trait, or to improve the power by accounting for environmental effects and other sources of trait variations. When one or more covariates are causally affected by both genetic variants and hidden confounders, adjusting for them in GWAS will produce biased estimation of SNP effects, known as collider bias. Several approaches have been developed to correct collider bias through estimating the bias by Mendelian randomization (MR). However, these methods work for only one covariate, some of which utilize MR methods with relatively strong assumptions, both of which may not hold in practice. In this paper, we extend the bias-correction approaches in two aspects: first we derive an analytical expression for the collider bias in the presence of multiple covariates, then we propose estimating the bias using a robust multivariable MR (MVMR) method based on constrained maximum likelihood (called MVMR-cML), allowing the presence of invalid instrumental variables (IVs) and correlated pleiotropy. We also established the estimation consistency and asymptotic normality of the new bias-corrected estimator. We conducted simulations to show that all methods mitigated collider bias under various scenarios. In real data analyses, we applied the methods to two GWAS examples, the first a GWAS of waist-hip ratio with adjustment for only one covariate, body-mass index (BMI), and the second a GWAS of BMI adjusting metabolomic principle components as multiple covariates, illustrating the effectiveness of bias correction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The emerging new VOC B.1.1.529 (Omicron) variant has raised serious concerns due to multiple mutations, reported significant immune escape, and unprecedented rapid spreading speed. Currently, studies ...describing the neutralization ability of different homologous and heterologous booster vaccination against Omicron are still lacking. In this study, we explored the immunogenicity of COVID-19 breakthrough patients, BBIBP-CorV homologous booster group and BBIBP-CorV/ZF2001 heterologous booster group against SARS-CoV-2 pseudotypes corresponding to the prototype, Beta, Delta, and the emergent Omicron variant.
Notably, at 14 days post two-dose inactivated vaccines, pVNT titre increased to 67.4 GMTs against prototype, 8.85 against Beta and 35.07 against Delta, while neutralization activity against Omicron was below the lower limit of quantitation in 80% of the samples. At day 14 post BBIBP-CorV homologous booster vaccination, GMTs of pVNT significantly increased to 285.6, 215.7, 250.8, 48.73 against prototype, Beta, Delta, and Omicron, while at day 14 post ZF2001 heterologous booster vaccination, GMTs of pVNT significantly increased to 1436.00, 789.6, 1501.00, 95.86, respectively. Post booster vaccination, 100% samples showed positive neutralization activity against Omicron, albeit illustrated a significant reduction (5.86- to 14.98-fold) of pVNT against Omicron compared to prototype at 14 days after the homologous or heterologous vaccine boosters.
Overall, our study demonstrates that vaccine-induced immune protection might more likely be escaped by Omicron compared to prototypes and other VOCs. After two doses of inactivated whole-virion vaccines as the "priming" shot, a third heterologous protein subunit vaccine and a homologous inactivated vaccine booster could improve neutralization against Omicron.
Periodontitis, an oral chronic inflammatory disease, is reported to show an association with atherosclerotic vascular disease.
is an oral commensal bacterium that is abundantly implicated in various ...forms of periodontal diseases; however, its role in the pathogenesis of atherosclerosis is unclear. This study aimed to elucidate the underlying pathogenic mechanisms of atherosclerosis induced by
to provide new insight on the prevention and treatment of atherosclerosis. We used an animal model, that is, ApoE
mice were infected with
by oral gavage, and
co-culture models to assess the pathogenicity of
The results indicate that
ATCC 25586 invaded aortic tissues and substantially increased the progression of atherosclerotic lesions. In addition,
changed plaque composition into a less-stable phenotype, characterized with increased subcutaneous macrophage infiltration, M1 polarization, lipid deposition, cell apoptosis, and reduced extracellular matrix and collagen content. The serum levels of pro-atherosclerotic factors, such as interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein-1 (MCP-1), c-reactive protein, and oxidized low-density lipoprotein (ox-LDL) and microRNAs (miR-146a, miR-155, and miR-23b) were considerably increased after
stimulation, whereas HDL-c level was reduced.
induced
macrophage apoptosis in a time- and dose-dependent manner.
facilitated ox-LDL-induced cholesterol phagocytosis and accumulation by regulating the expression of lipid metabolism-related genes (AR-A1, ACAT1, ABCA1, and ABCG1).
further worsened the atherosclerotic plaque microenvironment by considerably increasing the levels of IL-6; IL-1β; TNF-α; MCP-1; and MMP-2, 8, and 9 and by suppressing fibronectin (FN) 1 levels during foam cell formation. This study shows that
ATCC 25586 is implicated in atherosclerosis by causing aberrant activation and lipid metabolism in macrophage.
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