Analysis on characteristics of extreme precipitation indices and atmospheric circulation in Northern Shanxi

This article utilizes daily precipitation data from 28 national meteorological stations in northern Shanxi Province spanning from 1972 to 2020,and the US NCEP/NCAR monthly average reanalysis and ERA5 monthly average reanalysis data.The study employs techniques such as empirical orthogonal function(EOF)decomposition,MannKendall mutation and other methods to investigate the spatiotemporal distribution of extreme precipitation index in northern Shanxi and their correlation with atmospheric circulation.The research results show that:the absolute index,relative index,intensity index and sustained dry period index(CDD)in the continuous index appear from southwest to northeast.The spatial distribution characteristics of the central region decrease,while the continuous wet period(CWD)decreases from the central to the east and west.The three indices Rx1day,Rx5day,and CWD mutated in 1978,1975,and 1983 respectively,and other extreme precipitation indices all appeared in a sudden change from a low-value period to a high-value period occurred around 2010.In the high-value years of the summer extreme precipitation index,there is a significant negative anomaly in the height field in the mid-high latitude regions of Eurasia.Northern Shanxi is controlled by a broad low-pressure trough in the Lake Baikal area.Water vapor transported via the east,west,and south routes converges in the northern Shanxi region and encounters cold air from the north.There is a strong upward motion anomaly at 500 hPa in the troposphere,and the dynamic conditions of upper-level divergence and lower-level convergence lead to more summer extreme precipitation in the northern Shanxi region.Conversely,in the low-value years of the summer extreme precipitation index,northern Shanxi is affected by a strong high-pressure ridge north of Lake Baikal.There is a downward motion anomaly at 500 hPa,and the northern Shanxi region lacks water vapor.The cold and warm air cannot converge,and both the water vapor conditions and dynamic conditions are poor,which is not conducive to the production of extreme precipitation in northern Shanxi.

A randomized controlled clinical trial: Interruption of intrauterine transmission of hepatitis B virus infection with HBIG

AIM： To evaluate the efficacy of interruption of intrauterine infection of HBV with HBIG in pregnant women with positive HBeAg and HBsAg.METHODS： A prospective randomized controlled trial was adopted. Sixty cases with positive HBeAg and HBsAg were coincident with the criteria of inclusion, and 8 cases were excluded. Fifty-two cases were analyzed （28 cases in trial group and 24 in control group）. All cases in trial group received 200 IU HBIG intravenously every 4 wk for 3 times from the 28^th wk. The cases of control group received placebo in the same way. All pregnant women were detected for HBeAg and HBV-DNA at the beginning of the trial and end of the trial （delivery）. The cord blood of all newborns were collected for detecting HBeAg and HBV-DNA simultaneously.RESULTS： For investigation of HBeAg of newborns in trial group, 6 of 28 cases of newborns had positive HBeAg, the HBeAg positive rate being 21.4%, the total rate of 95% CI being 8%-41%. In control group, 19 of 24 cases of newborns had positive HBeAg, HBeAg positive rate was 79.2%, the rate of 95%CI being 5%-93%. By statistical analysis, 2= 17.26, P 〈 0.01, RR = 0.27, 95% CI （6.3 × 10^-6, 8.6 × 10^-5）. For investigation of HBV-DNA of newborns in trial group, 7 of 28 cases of newborns had positive HBV-DNA, HBV-DNA positive rate being 25%, the total rate of 95% CI being 11%-45%. In control group, 20 of 24 cases of newborns had positive HBV-DNA, HBV-DNA positive rate was 83.3%, the total rate of 95% CI being 63%-95%. By statistical analysis, X^2 = 17.62, P 〈 0.01, RR = 0.30, 95% CI （1.5 × 10^-5, 1.7× 10^-4）. The results indicated that there was significant difference in HBeAg positive rate and HBV-DNA positive rate of newborns between the two groups. In trial group, 7 of 28 newborns had HBV-DNA positive, but the HBV-DNA load of newborns was lower than that of their mothers. In control group, 20 of 24 newborns still had HBV-DNA positive, and the HBV-DNA load of newborns was close to those of their mothers. Statistical analysis indicated that there was no significant difference in HBV- DNA load between postnatal women without HBIG intervention and their filial generations （T = 81.5, P 〉 0.1）. CONCLUSION： It is effective and safe to prevent intrauterine infection of HBV with HBIG from the 28^th wk in pregnant women with positive HBeAg and HBsAg. In clinical application, those pregnant women with negative HBeAg and positive HBV-DNA also need to be interrupted by HBIG.

Correlation analysis of the total IgY level in hen serum, egg yolk and offspring serum

The correlation between IgY levels of the serum and the yolk has been well documented in wild and domestic birds. The levels of total yolk IgY can be an index of the general health status of birds and may contribute to breeding programs when fitness of the offspring is a concern. We measured the levels of total serum IgY and yolk IgY in three different breeds （White Leghorn, Silkie and Dongxiang blue-shell） using indirect ELISA, and found that there was a significantly positive correlation between the levels of total serum IgY and total yolk IgY in all three breeds （White Leghorn： r = 0.404, P 〈 0.001, n = 100; Silkie： r = 0.561, P 〈 0.001, n = 70; Dongxiang blue-shell： r = 0.619, P 〈 0.001, n = 30）. We also measured the total serum IgY levels in the 3-day-old offspring hatched from the Silkie hens and results were significantly correlated for serum IgY levels （r = 0.535, P 〈 0.001, n = 70） and the yolk IgY levels （r = 0.481, P 〈 0.001, n = 70）. The regression analysis showed simple linear regression between IgY levels in hen serum, yolk and offspring serum. Our results suggest that total IgY level could be used as an index for chicken fitness.

LipR functions as an intracellular pH regulator in Bacillus thuringiensis under glucose conditions

Intracellular pH critically affects various biological processes,and an appropriate cytoplasmic pH is essential for ensuring bacterial growth.Glucose is the preferred carbon source for most heterotrophs;however,excess glucose often causes the accumulation of acidic metabolites,lowering the intracellular pH and inhibiting bacterial growth.Bacillus thuringiensis can effectively cope with glucose-induced stress;unfortunately,little is known about the regulators involved in this process.Here,we document that the target of the dual-function sRNA YhfH,the lipR gene,encodes a LacI-family transcription factor LipR as an intracellular pH regulator when B.thuringiensis BMB171 is suddenly exposed to glucose.Under glucose conditions,lipR deletion leads to early growth arrest by causing a rapid decrease in intracellular pH(~5.4).Then,the direct targets and a binding motif(GAWAWCRWTWTCAT)of LipR were identified based on the electrophoretic mobility shift assay,the DNase-I footprinting assay,and RNA sequencing,and the gapN gene encoding a key enzyme in glycolysis was directly inhibited by LipR.Furthermore,Ni^(2+)is considered a possible effector for LipR.In addition to YhfH,the lipR expression was coregulated by itself,CcpA,and AbrB.Our study reveals that LipR plays a balancing role between glucose metabolism and intracellular pH in B.thuringiensis subjected to glucose stress.

Localization and Dynamic Change of Saikosaponin in Root of Bupleurum chinense

Anatomical, histochemical and phytochemical methods were used to investigate the structure, the localization and content changes of total saikosaponin and saikosaponin-a of the roots of Bupleurum chinense DC. at different developmental stages. Results showed that saikosaponin was mainly distributed in pericycle and primary phloem in the young root; but in the mature root, it was mainly distributed in vascular cambium and secondary phloem. During the whole growth period from the pre-blossom, blossom, fruit, and fruit mature periods until the pre-withering period, it was in the fruit mature period that both the total saikosaponin content and the saikosaponin-a content reached the highest level. So the last 20 d of October was considered as the right collecting season for the drug of B. chinense. In addition, the quality of 1-year-old drug was better than that of 2-year-old drug due to its higher saikosaponin content. On the other hand, judging from the external characteristics of the drug, the one with an acerose taproot and more lateral roots was of better quality. The results offered theoretical bases for selecting medicinal material of high quality and determining the most appropriate harvesting stage and part of B. chinense.

Localization and Dynamic Change of Saponin in Vegetative Organs of Polygala tenuifolia

Anatomical, histochemical and phytochemical methods were used to investigate the structure, localization and dynamic changes of total saponin and senegenin of vegetative organs in Polygala tenuifolia Willd. Histochemical localization results showed that saponin accumulated mainly in parenchyma cells of vegetative organs. The phytochemical results also showed that the saponin accumulated in the vegetative organs of P. tenuifolia, with higher content in roots and lower content in the aerial parts that included stems and leaves. The saponin content and dry weight of the vegetative organs of P. tenuifolia had dynamic variance at the developmental stages and all reached the highest level in the post-fruit period. Hence, the roots and aerial parts should be gathered in August to make full use of the plant. As the root is the main medicinal organ of P. tenuifolia, the content of total saponin and senegenin of different aged and different parts of the root were determined. The content of total saponin and senegenin exhibited a sustained decreasing trend with increasing root age; therefore, the annual roots had high quality. The content of total saponin and senegenin in different parts of the root showed obvious variation. The content in the ＂skin areas＂ was much higher than that of xylem. The results offer a theoretical basis for determining the appropriate harvesting stage and a reasonable harvest of P. tenuifolia.

RBD-Fc-based COVID-19 vaccine candidate induces highly potent SARS-CoV-2 neutralizing antibody response

The pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has posed serious threats to global health and economy,thus calling for the development of safe and effective vaccines.The receptorbinding domain(RBD)in the spike protein of SARS-CoV-2 is responsible for its binding to angiotensin-converting enzyme 2(ACE2)receptor.It contains multiple dominant neutralizing epitopes and serves as an important antigen for the development of COVID-19 vaccines.Here,we showed that immunization of mice with a candidate subunit vaccine consisting of SARS-CoV-2 RBD and Fc fragment of human IgG,as an immunopotentiator,elicited high titer of RBD-specific antibodies with robust neutralizing activity against both pseudotyped and live SARS-CoV-2 infections.The mouse antisera could also effectively neutralize infection by pseudotyped SARS-CoV-2 with several natural mutations in RBD and the IgG extracted from the mouse antisera could also show neutralization against pseudotyped SARS-CoV and SARS-related coronavirus(SARSr-CoV).Vaccination of human ACE2 transgenic mice with RBD-Fc could effectively protect mice from the SARS-CoV-2 challenge.These results suggest that SARS-CoV-2 RBD-Fc has good potential to be further developed as an effective and broad-spectrum vaccine to prevent infection of the current SARS-CoV-2 and its mutants,as well as future emerging SARSr-CoVs and re-emerging SARS-CoV.

Griffithsin with A Broad-Spectrum Antiviral Activity by Binding Glycans in Viral Glycoprotein Exhibits Strong Synergistic Effect in Combination with A Pan-Coronavirus Fusion Inhibitor Targeting SARS-CoV-2 Spike S2 Subunit

Dear Editor,The pandemic of coronavirus disease 2019(COVID-19)caused by SARS-Co V-2 has posed a significant threat to global public health and economy,thus calling for the rapid development of effective therapeutics and prophylactics.Repurposing existing medicines with clinical safety profiles offers a more rapid hope of combating COVID-19pandemic than developing a new therapeutic.

A practical reference for studying meiosis in the model ciliate Tetrahymena thermophila

Meiosis is a critical cell division program that produces haploid gametes for sexual reproduction.Abnormalities in meiosis are often causes of infertility and birth defects(e.g.,Down syndrome).Most organisms use a highly specialized zipper-like protein complex,the synaptonemal complex(SC),to guide and stabilize pairing of homologous chromosomes in meiosis.Although the SC is critical for meiosis in many eukaryotes,there are organisms that perform meiosis without a functional SC.However,such SC-less meiosis is poorly characterized.To understand the features of SC-less meiosis and its adaptive significance,the ciliated protozoan Tetrahymena was selected as a model.Meiosis research in Tetrahymena has revealed intriguing aspects of the regulatory programs utilized in its SC-less meiosis,yet additional efforts are needed for obtaining an in-depth comprehension of mechanisms that are associated with the absence of SC.Here,aiming at promoting a wider application of Tetrahymena for meiosis research,we introduce basic concepts and core techniques for studying meiosis in Tetrahymena and then suggest future directions for expanding the current Tetrahymena meiosis research toolbox.These methodologies could be adopted for dissecting meiosis in poorly characterized ciliates that might reveal novel features.Such data will hopefully provide insights into the function of the SC and the evolution of meiosis from a unique perspective.

Effect of chlorine dioxide on avian influenza A(H7N9)virus

Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.

Structural and functional basis for pan-CoV fusion inhibitors against SARS-CoV-2 and its variants with preclinical evaluation

The COVID-19 pandemic poses a global threat to public health and economy.The continuously emerging SARS-CoV-2 variants present a major challenge to the development of antiviral agents and vaccines.In this study,we identified that EK1 and cholesterol-coupled derivative of EK1,EK1C4,as pan-CoV fusion inhibitors,exhibit potent antiviral activity against SARS-CoV-2 infection in both lung-and intestine-derived cell lines(Calu-3 and Caco2,respectively).They are also effective against infection of pseudotyped SARS-CoV-2 variants B.1.1.7(Alpha)and B.l.1.248(Gamma)as well as those with mutations in S protein,including N417T,E484K,N501Y,and D614G,which are common in South African and Brazilian variants.Crystal structure revealed that EK1 targets the HR1 domain in the SARS-CoV-2 S protein to block virus-cell fusion and provide mechanistic insights into its broad and effective antiviral activity.Nasal administration of EK1 peptides to hACE2 transgenic mice significantly reduced viral titers in lung and intestinal tissues.EK1 showed good safety profiles in various animal models,supporting further clinical development of EK1-based pan-CoV fusion inhibitors against SARS-CoV-2 and its variants.

Data-driven design of high-performance MASnxPb1-xI3 perovskite materials by machine learning and experimental realization

The photovoltaic performance of perovskite solar cell is determined by multiple interrelated factors,such as perovskite compositions,electronic properties of each transport layer and fabrication parameters,which makes it rather challenging for optimization of device performances and discovery of underlying mechanisms.Here,we propose and realize a novel machine learning approach based on forward-reverse framework to establish the relationship between key parameters and photovoltaic performance in high-profile MASnxPb1-xI3 perovskite materials.The proposed method establishes the asymmetrically bowing relationship between band gap and Sn composition,which is precisely verified by our experiments.Based on the analysis of structural evolution and SHAP library,the rapid-change region and low-bandgap plateau region for small and large Sn composition are explained,respectively.By establishing the models for photovoltaic parameters of working photovoltaic devices,the deviation of short-circuit current and open-circuit voltage with band gap in defective-zone and low-bandgap-plateau regions from Shockley-Queisser theory is captured by our models,and the former is due to the deep-level traps formed by crystallographic distortion and the latter is due to the enhanced susceptibility by increased Sn4+content.The more difficulty for hole extraction than electron is also concluded in the models and the prediction curve of power conversion efficiency is in a good agreement with Shockley-Queisser limit.With the help of search and optimization algorithms,an optimized Sn:Pb composition ratio near 0.6 is finally obtained for high-performance perovskite solar cells,then verified by our experiments.Our constructive method could also be applicable to other material optimization and efficient device development.

ProtoporphyrinⅨand verteporfin potently inhibit SARS-CoV-2 infection in vitro and in a mouse model expressing human ACE2

The SARS-CoV-2 infection is spreading rapidly worldwide.Efficacious antiviral therapeutics against SARSCo V-2 is urgently needed.Here,we discovered that protoporphyrin IX(Pp IX)and verteporfin,two Food and Drug Administration(FDA)-approved drugs,completely inhibited the cytopathic effect produced by SARS-CoV-2 infection at 1.25 lmol/L and 0.31 lmol/L,respectively,and their EC50 values of reduction of viral RNA were at nanomolar concentrations.The selectivity indices of Pp IX and verteporfin were 952.74 and 368.93,respectively,suggesting a broad margin of safety.Importantly,Pp IX and verteporfin prevented SARS-CoV-2 infection in mice adenovirally transduced with human angiotensin-converting enzyme 2(ACE2).The compounds,sharing a porphyrin ring structure,were shown to bind viral receptor ACE2 and interfere with the interaction between ACE2 and the receptor-binding domain of viral S protein.Our study suggests that Pp IX and verteporfin are potent antiviral agents against SARS-CoV-2 infection and sheds new light on developing novel chemoprophylaxis and chemotherapy against SARS-CoV-2.