Eosin Y, a well‐known economical alternative to metal catalysts in visible‐light‐driven single‐electron transfer‐based organic transformations, can behave as an effective direct hydrogen‐atom ...transfer catalyst for C−H activation. Using the alkylation of C−H bonds with electron‐deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y‐based photocatalytic hydrogen‐atom transfer strategy is promising for diverse functionalization of a wide range of native C−H bonds in a green and sustainable manner.
Neutral eosin Y has been employed as an effective direct hydrogen‐atom transfer photocatalyst to activate a wide range of native C−H bonds in a green and sustainable fashion. This transformation is distinguished by its operational simplicity and amenability to large‐scale synthesis using continuous‐flow technology (EWG=aldehyde, ketone, ester, amide, imide, cyanide, sulfone, nitro, pyridine).
Zika virus (ZIKV) belongs to the positive-sense single-stranded RNA-containing
Flaviviridae
family. Its recent outbreak and association with human diseases (e.g. neurological disorders) have raised ...global health concerns, and an urgency to develop a therapeutic strategy against ZIKV infection. However, there is no currently approved antiviral against ZIKV. Here we present a comprehensive overview on recent progress in structure–function investigation of ZIKV NS5 protein, the largest non-structural protein of ZIKV, which is responsible for replication of the viral genome, RNA capping and suppression of host interferon responses. Structural comparison of the N-terminal methyltransferase domain and C-terminal RNA-dependent RNA polymerase domain of ZIKV NS5 with their counterparts from related viruses provides mechanistic insights into ZIKV NS5-mediated RNA replication, and identifies residues critical for its enzymatic activities. Finally, a collection of recently identified small molecule inhibitors against ZIKV NS5 or its closely related flavivirus homologues are also discussed.
Conversion of levulinic acid to valuable chemicals: a review Xu, Wen‐Ping; Chen, Xue‐Fang; Guo, Hai‐Jun ...
Journal of chemical technology and biotechnology (1986),
November 2021, 2021-11-00, 20211101, Letnik:
96, Številka:
11
Journal Article
Microplastics have been widely detected in the environment and marine organisms. However, few studies have investigated the presence of microplastics in humans. This preliminary study identified and ...quantified the microplastic content in human feces.
A total of 26 young male students aged 18–25 years were recruited from Beijing, China. A self-administered 7-day 24-h fluid intake record was used to document fluid intake, and food intake was recorded for 3 days. Feces were collected by participants using a sterile fecal collector. Microplastics in the remaining fecal residues were measured and identified using fourier transform infrared micro-spectroscopy.
Eventually, twenty-four participants completed the study. The fecal samples of 23 (95.8%) participants tested positive for microplastics. In these 23 samples, the abundance of microplastics varied from 1 particle/g to 36 particles/g (size 20 to 800 μm). The summed mass of all microplastic particles per participant ranged from 0.01 to 14.6 mg. Qualitative analysis of the microplastics indicated the presence of one to eight types of microplastics in each sample, with polypropylene (PP) being the most abundant; it was found in 95.8% of fecal samples. We examined associations between water intake habits and the abundance of microplastics in their feces. A moderate correlation was observed between packaged water and beverage intake and microplastic abundance in feces (r = 0.445, P = 0.029).
Various types of microplastics were detected in human feces, with PP being found in the highest proportion. There may be an association between water intake habits and microplastic abundance in feces.
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•Microplastics have been found in human feces.•The highest proportion of microplastic components was polypropylene.•Sources of water intake may one of the influencing factors on the content of microplastics in the human gastrointestinal tract.•More attention should be paid to the widespread existence of microplastics and its health effects.
Simple thiol derivatives, such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play key roles in biological processes, and the fluorescent probes to detect such thiols
in vivo
...selectively with high sensitivity and fast response times are critical for understanding their numerous functions. However, the similar structures and reactivities of these thiols pose considerable challenges to the development of such probes. This review focuses on various strategies for the design of fluorescent probes for the selective detection of biothiols. We classify the fluorescent probes for discrimination among biothiols according to reaction types between the probes and thiols such as cyclization with aldehydes, conjugate addition-cyclization with acrylates, native chemical ligation, and aromatic substitution-rearrangement.
This review focuses on various strategies for the design of fluorescent probes for selective detection of biothiols, which are classified according to the unique reaction types between probes and thiols, such as cyclization with aldehydes, conjugate addition-cyclization with acrylates, native chemical ligation, and aromatic substitution-rearrangement.
Exhaustion of cytotoxic effector natural killer (NK) and CD8
T cells have important functions in the establishment of persistent viral infections, but how exhaustion is induced during chronic ...hepatitis C virus (HCV) infection remains poorly defined. Here we show, using the humanized C/O
mice permissive for persistent HCV infection, that NK and CD8
T cells become sequentially exhausted shortly after their transient hepatic infiltration and activation in acute HCV infection. HCV infection upregulates Qa-1 expression in hepatocytes, which ligates NKG2A to induce NK cell exhaustion. Antibodies targeting NKG2A or Qa-1 prevents NK exhaustion and promotes NK-dependent HCV clearance. Moreover, reactivated NK cells provide sufficient IFN-γ that helps rejuvenate polyclonal HCV CD8
T cell response and clearance of HCV. Our data thus show that NKG2A serves as a critical checkpoint for HCV-induced NK exhaustion, and that NKG2A blockade sequentially boosts interdependent NK and CD8
T cell functions to prevent persistent HCV infection.
Context: Coptidis rhizome (CR), also known as Huanglian in Chinese, is the rhizome of Coptis chinensis Franch., C. deltoidea C.Y. Cheng et Hsiao, or C. teeta Wall (Ranunculaceae). It has been widely ...used to treat bacillary dysentery, diabetes, pertussis, sore throat, aphtha, and eczema in China.
Objectives: The present paper reviews the latest advances of CR, focusing on the botany, phytochemistry, traditional usages, pharmacokinetics, pharmacology and toxicology of CR and its future perspectives.
Methods: Studies from 1985 to 2018 were reviewed from books; PhD. and MSc. dissertations; the state and local drug standards; PubMed; CNKI; Scopus; the Web of Science; and Google Scholar using the keywords Coptis, Coptidis Rhizoma, Huanglian, and goldthread.
Results: Currently, 128 chemical constituents have been isolated and identified from CR. Alkaloids are the characteristic components, together with organic acids, coumarins, phenylpropanoids and quinones. The extracts/compounds isolated from CR cover a wide pharmacological spectrum, including antibacterial, antivirus, antifungal, antidiabetic, anticancer and cardioprotective effects. Berberine is the most important active constituent and the primary toxic component of CR.
Conclusions: As an important herbal medicine in Chinese medicine, CR has the potential to treat various diseases. However, further research should be undertaken to investigate the clinical effects, toxic constituents, target organs and pharmacokinetics, and to establish criteria for quality control, for CR and its related medications. In addition, the active constituents, other than alkaloids, in both raw and processed products of CR should be investigated.
Optimality of the premise, IF part is critical to a zero-order evolving intelligent system (EIS) because this part determines the validity of the learning results and overall system performance. ...Nonetheless, a systematic analysis of optimality has not been done yet in the state-of-the-art works. In this paper, we use the recently introduced self-organising neuro-fuzzy inference system (SONFIS) as an example of typical zero-order EISs and analyse the local optimality of its solutions. The optimality problem is firstly formulated in a mathematical form, and detailed optimality analysis is conducted. The conclusion is that SONFIS does not generate a locally optimal solution in its original form. Then, an optimisation method is proposed for SONFIS, which helps the system to attain local optimality in a few iterations using historical data. Numerical examples presented in this paper demonstrate the validity of the optimality analysis and the effectiveness of the proposed optimisation method. In addition, it is further verified numerically that the proposed concept and general principles can be applied to other types of zero-order EISs with similar operating mechanisms.
People with serious mental illness are at great risk of suicide, but little is known about the suicide rates among this population. We aimed to quantify the suicide rates among people with serious ...mental illness (bipolar disorder, major depression, or schizophrenia).
PubMed and Web of Science were searched to identify studies published from 1 January 1975 to 10 December 2020. We assessed English-language studies for the suicide rates among people with serious mental illness. Random-effects meta-analysis was used. Changes in follow-up time and the suicide rates were presented by a locally weighted scatter-plot smoothing (LOESS) curve. Suicide rate ratio was estimated for assessments of difference in suicide rate by sex.
Of 5014 identified studies, 41 were included in this analysis. The pooled suicide rate was 312.8 per 100 000 person-years (95% CI 230.3-406.8). Europe was reported to have the highest pooled suicide rate of 335.2 per 100 000 person-years (95% CI 261.5-417.6). Major depression had the highest suicide rate of 534.3 per 100 000 person-years (95% CI 30.4-1448.7). There is a downward trend in suicide rate estimates over follow-up time. Excess risk of suicide in males was found 1.90 (95% CI 1.60-2.25). The most common suicide method was poisoning 21.9 per 100 000 person-years (95% CI 3.7-50.4).
The suicide rates among people with serious mental illness were high, highlighting the requirements for increasing psychological assessment and monitoring. Further study should focus on region and age differences in suicide among this population.
PM2.5 samples were collected at an urban site (WD) and a suburban site (TH) in Wuhan from August 2012 to July 2013. The mass concentrations of water-soluble inorganic ions, carbonaceous species and ...elements of PM2.5 were measured. The annual mean concentrations of PM2.5 were 106.5μg/m3 and 114.9μg/m3 at WD and TH, respectively. The chemical compositions of PM2.5 at WD were similar to those at TH and the fractions of the major components of PM2.5 in Wuhan were in the following order of trace elements<chloride<EC (elemental carbon)<ammonium<nitrate<soil dust<sulfate<OM (organic matter). As the secondary ionic aerosols (SIA) and dominant ions, SO42−, NO3− and NH4+ all exhibited strong seasonal distributions, consistently with the lowest values in summer and the highest in winter. OM was the most abundant component in PM2.5, the lowest concentrations of which were observed in summer at both sites, while the highest concentrations of OC (organic carbon) appeared in winter at WD and autumn at TH, respectively. The highest OC concentration observed in autumn was tightly related to the biomass burning near the suburban site. The crustal elements (Mg, K, Ca and Fe) dominated the 20 detected elements in PM2.5, with the highest concentrations in spring in Wuhan, which might be due to frequent sandstorm from north carrying abundant soil dusts in spring in China. Ten trace elements (Cu, Ga, Ag, Tl, Ca, As, Zn, Pb, Se and Cd) were enriched in PM2.5 and the higher EF for Ag, Pb, Se and Cd in PM2.5 indicated that the air pollution from vehicle exhaust emission and coal burning in Wuhan was serious and noteworthy.
•PM2.5 is a pollutant of regional concern in Wuhan, Central China.•The mass concentrations of water-soluble inorganic ions, carbonaceous species and elements of PM2.5 were measured.•The air pollution from vehicle exhaust emission and coal burning in Wuhan was serious and noteworthy.
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