Membrane vesicles derived from Streptococcus suis serotype 2 induce cell pyroptosis in endothelial cells via the NLRP3/Caspase-1/GSDMD pathway

Streptococcus suis serotype 2(S.suis 2)is a zoonotic pathogen that clinically causes severe swine and human infections(such as meningitis,endocarditis,and septicemia).In order to cause widespread diseases in different organs,S.suis 2 must colonize the host,break the blood barrier,and cause exaggerated inflammation.In the last few years,most studies have focused on a single virulence factor and its influences on the host.Membrane vesicles(MVs)can be actively secreted into the extracellular environment contributing to bacteria-host interactions.Gram-negative bacteria-derived outer membrane vesicles(OMVs)were recently shown to activate host Caspase-11-mediated non-canonical inflammasome pathway via deliverance of OMV-bound lipopolysaccharide(LPS),causing host cell pyroptosis.However,little is known about the effect of the MVs from S.suis 2(Gram-positive bacteria without LPS)on cell pyroptosis.Thus,we investigated the molecular mechanism by which S.suis 2 MVs participate in endothelial cell pyroptosis.In this study,we used proteomics,electron scanning microscopy,fluorescence microscope,Western blotting,and bioassays,to investigate the MVs secreted by S.suis 2.First,we demonstrated that S.suis 2 secreted MVs with an average diameter of 72.04 nm,and 200 proteins in MVs were identified.Then,we showed that MVs were transported to cells via mainly dynamin-dependent endocytosis.The S.suis 2 MVs activated NLRP3/Caspase-1/GSDMD canonical inflammasome signaling pathway,resulting in cell pyroptosis,but it did not activate the Caspase-4/-5 pathway.More importantly,endothelial cells produce large amounts of reactive oxygen species(ROS)and lost their mitochondrial membrane potential under induction by S.suis 2 MVs.The results in this study suggest for the first time that MVs from S.suis 2 were internalized by endothelial cells via mainly dynamin-dependent endocytosis and might promote NLRP3/Caspase-1/GSDMD pathway by mitochondrial damage,which produced mtDNA and ROS under induction,leading to the pyroptosis of endothelial cells.

Porcine enteric alphacoronavirus infection increases lipid droplet accumulation to facilitate the virus replication

Coronaviruses are widely transmissible between humans and animals, causing diseases of varying severity. Porcine enteric alphacoronavirus(PEAV) is a newly-discovered pathogenic porcine enteric coronavirus in recent years, which causes watery diarrhea in newborn piglets. The host inflammatory responses to PEAV and its metabolic regulation mechanisms remain unclear, and no antiviral studies have been reported. Therefore, we investigated the pathogenic mechanism and antiviral drugs of PEAV. The transcriptomic analysis of PEAV-infected host cells revealed that PEAV could upregulate lipid metabolism pathways. In lipid metabolism, steady-state energy processes, which can be mediated by lipid droplets(LDs), are the main functions of organelles. LDs are also important in viral infection and inflammation. In infected cells, PEAV increased LD accumulation, upregulated NF-κB signaling, promoted the production of the inflammatory cytokines IL-1β and IL-8, and induced cell death. Inhibiting LD accumulation with a DGAT-1 inhibitor significantly inhibited PEAV replication, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. The NF-κB signaling pathway inhibitor BAY11-7082 significantly inhibited LD accumulation and PEAV replication. Metformin hydrochloride also exerted anti-PEAV effects and significantly inhibited LD accumulation, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. LD accumulation in the lipid metabolism pathway therefore plays an important role in the replication and pathogenesis of PEAV, and metformin hydrochloride inhibits LD accumulation and the inflammatory response to exert anti-PEAV activity and reducing pathological injury. These findings contribute new targets for developing treatments for PEAV infections.

Accurate models and nutritional strategies for specific oxidative stress factors: Does the dose matter in swine production?

Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.

A fast ionic transport copolymeric network for stable quasi-solid lithium metal battery

Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery.

Effects of zinc on χ-Fe_(5)C_(2) for carbon dioxide hydrogenation to olefins:Insights from experimental and density function theory calculations

Production of light olefins from CO_(2), the primary greenhouse gases, is of great importance to mitigate the adverse effects of CO_(2) emission on environment and to supply the value-added products from nonpetroleum resource. However, development of robust catalyst with controllable selectivity and stability remains a challenge. Herein, we report that Zn-promoted Fe catalyst can boost the stable and selective production of light olefins from CO_(2). Specifically, the Zn-promoted Fe exhibits a highly stable activity and olefin selectivity over 200 h time-on-stream compared to the unpromoted Fe catalyst, primarily owing to the preservation of active χ-Fe_(5)C_(2) phase. Structural characterizations of the spent catalysts suggest that Zn substantially regulates the content of iron carbide on the surface and suppresses the reoxidation of bulk iron carbide during the reaction. DFT calculations confirm that adsorption of surface carbon atoms and graphene-like carbonaceous species are not thermochemically favored on Zn-promoted Fe catalyst. Carbon deposition by CAC coupling reactions of two surface carbon atoms and dehydrogenation of CH intermediate are also inhibited. Furthermore, the effects of Zn on antioxidation of iron carbide were also investigated. Zn favored the hydrogenation of surface adsorbed oxygen atoms to H_(2)O and the desorption of H_(2)O, which reduces the possibility of surface carbide being oxidized by the chemisorbed oxygen.

Different dietary starch sources alter the carcass traits, meat quality, and the profile of muscle amino acid and fatty acid in finishing pigs

Background: With increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis(L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen.Tapioca starch(TS), corn starch(CS), and pea starch(PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44,respectively, were used as their dietary starch sources for 40 days.Results: Results showed that the PS diet significantly increased(P < 0.05) the final body weight, average daily gain,loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased(P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased(P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased(P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased(P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid(PUFA) in the L. thoracis compared with TS diet,but decreased(P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated(P < 0.05) the lipogenic genes(FAS, LPL, SCD, ACCα) and myosin heavy-chain(MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated(P < 0.05) the CPT1 B and MyHC-IIb mRNA levels.Conclusions: In conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork.

Dietary resveratrol attenuation of intestinal inflammation and oxidative damage is linked to the alteration of gut microbiota and butyrate in piglets challenged with deoxynivalenol

Background:Deoxynivalenol(DON)is a widespread mycotoxin that induces intestinal inflammation and oxidative stress in humans and animals.Resveratrol(RES)effectively exerts anti-inflammatory and antioxidant effects.However,the protective effects of RES on alleviating DON toxicity in piglets and the underlying mechanism remain unclear.Therefore,this study aimed to investigate the effect of RES on growth performance,gut health and the gut microbiota in DON-challenged piglets.A total of 64 weaned piglets[Duroc×(Landrace×Yorkshire),21-d-old,6.97±0.10 kg body weight(BW)]were randomly allocated to 4 treatment groups(8 replicate pens per treatment,each pen containing 2 males;n=16 per treatment)for 28 d.The piglets were fed a control diet(CON)or the CON diet supplemented with 300 mg RES/kg diet(RES group),3.8 mg DON/kg diet(DON)or both(DON+RES)in a 2×2 factorial design.Results:DON-challenged piglets fed the RES-supplemented diet had significantly decreased D-lactate concentrations and tumor necrosis factor alpha(TNF-α)and interleukin 1 beta(IL-1β)mRNA and protein expression,and increased zonula occludens-1(ZO-1)mRNA and protein expression compared with those of DON-challenged piglets fed the unsupplemented diet(P<0.05).Compared with unsupplemented DON-challenged piglets,infected piglets fed a diet with RES showed significantly decreased malondialdehyde(MDA)levelsand increased mRNA expression of antioxidant enzymes and antioxidant genes(i.e.,GCLC,GCLM,HO-1,SOD1 and NQO-1)and glutamatecysteine-ligase modulatory subunit(GCLM)protein expression(P<0.05).Moreover,RES supplementation significantly abrogated the increase in the proportion of TUNEL-positive cells and the protein expression of caspase3 in DON-challenged piglets(P<0.05).Finally,RES supplementation significantly increased the abundance of Roseburia and butyrate concentrations,while decreasing the abundances of Bacteroides and unidentified-Enterobacteriaceae in DON-challenged piglets compared with DON-challenged piglets alone(P<0.05).Conclusions:RES supplementation improved gut health in DON-challenged piglets by strengthening intestinal barrier function,alleviating intestinal inflammation and oxidative damage,and positively modulating the gut microbiota.The protective effects of RES on gut health may be linked to increased Roseburia and butyrate concentrations,and decreased levels of Bacteroides and unidentified-Enterobacteriaceae.

Alterations in intestinal microbiota composition coincide with impaired intestinal morphology and dysfunctional ileal immune response in growing-finishing pigs under constant chronic heat stress

Background:Previous studies had shown that short-term acute heat stress(HS)affected the host’s metabolism and intestinal microbiota independent of feed intake(FI)reduction,and long-term calorie restriction caused intestinal morphological injuries and gut microbial alterations.However,research on the effects of constant chronic HS on intestinal microbial composition and the roles of FI reduction played in is limited.This study aimed to investigate the effects of 7-day constant chronic HS on the composition of intestinal microbes in growing-finishing pigs,and its relationship with pigs’performance,intestinal morphology,and ileal immune response.Twenty-four growingfinishing pigs(Duroc×Large White×Landrace,30±1 kg body weight)were randomly assigned to three treatments(n=8),1)thermal neutral(TN)conditions(25±1℃)with ad libitum FI,2)HS conditions(35±1℃)with ad libitum FI,3)pair-fed(PF)with HS under TN conditions to discriminate the confounding effects of dissimilar FI,and the FI was the previous day’s average FI of HS.The small intestinal segments(duodenum,jejunum,and ileum)and feces were collected on d 8.Results:Results indicated that HS drastically declined(P<0.05)average daily gain(ADG)and average daily feed intake(ADFI)(about 61%)in comparison with TN,and caused hyperpyrexia,meanwhile PF caused hypothermia.Morphological observation by light and electron microscopes showed that both HS and PF treatment decreased(P<0.05)the villus and microvillus height compared with TN.Additionally,HS increased(P<0.05)protein expression of heat shock protein 70 in the duodenum,jejunum,and ileum.Furthermore,the expression of tight junction protein zonula occluden-1(ZO-1)in the duodenum and ileum,and Occludin in the ileum were enhanced(P<0.05)compared with TN and PF.Moreover,HS significantly enhanced(P<0.05)the mRNA relative expression of inflammatory cytokines(TLR-2,TLR-4,and tumor necrosis factor-α(TNF-α),IL-6,IL-8,PG1–5,β-defensin 2(pBD-2)),mucins(mucin-1 and mucin-2)and P65 protein level in the ileal mucosa tissue.Intestinal microbiota analysis by 16S rRNA sequencing showed lower(P<0.10)αdiversity in both HS and PF,and a separated cluster ofβdiversity among groups.Compared with TN,HS but not PF mainly reduced(FDR<0.05)Bacteroidetes(phylum),Bacteroidia(class)and elevated the proportions of Proteobacteria(phylum,FDR<0.05),Bacillales(order,FDR<0.05),Planococcaceae(family,FDR<0.05),Kurthia(genus,FDR<0.05),Streptococcaceae(family,FDR<0.10)and Streptococcus(genus,FDR<0.10).Notably,Lactobacillales(order)was decreased(FDR<0.05)by PF alone.Furthermore,the Spearman correlation analysis indicated that the microbes prevalent in HS were positively(P<0.05)associated with intestinal morphological injuries indicators and ileal immune response parameters,and the microbes reduced in HS were negatively(P<0.05)with the performance data.Conclusions:Intestinal morphological injuries and ileal immune response caused by constant chronic HS independent of FI showed close connections with alterations in intestinal microbiota in growing-finishing pigs.

Operation and Optimization of Residue Hydrotreating Unit Using New Catalyst System

This article has summarized the optimized measures relating to the loading of catalyst,and the sixth operating cycle of the residue hydrotreating unit at SINOPEC's Maoming Branch Company,and made a detailed comparison on the impurities removal rate,hydrogen consumption and energy consumption of the sixth operating cycle with those achieved by the previous five cycles.Test results have revealed that the second-generation RHT series novel residue hydrotreating catalysts featured high activity,good stability,and long operating cycle and could remarkably reduce the hydrogen consumption and energy consumption of process unit.The hydrotreated AR product,having low Conradson carbon residue,low sulfur content,low metal content,high content of saturated hydrocarbons,and low content of asphaltenes and resins,is an excellent FCC feed.Judging from their overall property the second-generation RHT series of residue hydrotreating catalysts used in the sixth operating cycle have commanded a leading position among other catalysts used in previous operating cycles.

First identification of two co-existing genome-wide significant sex quantitative trait loci(QTL) in red tilapia using integrative QTL mapping

Red tilapia(Oreochromis spp.)is one of the most popular fish in China due to its bright red appearance,fast growth rate,and strong adaptability.Understanding the sex determination mechanisms is of vital importance for the selection of all-male lines to increase aquacultural production of red tilapia.In this research,the genetic architecture for sex from four mapping populations(n=1090)of red tilapia was analyzed by quantitative trait loci(QTL)-seq,linkage-based QTL mapping,and linkage disequilibrium(LD)-based genome-wide association studies.Two genome-wide significant QTL intervals associated with sex were identified on ChrLG1(22.4-23.9 Mb)and ChrLG23(32.0-35.9 Mb),respectively.The QTL on ChrLG1 was detected in family 1(FAM1),FAM2,and FAM4,and the other QTL on ChrLG23 was detected in FAM3 and FAM4.Four microsatellite markers located within the QTL were successfully developed for marker-assisted selection.Interestingly,three(Ipp,sox14,and amh)of the 12 candidate genes located near or on the two QTL intervals were abundantly expressed in males,while the remaining genes were more highly expressed in females.Seven genes(scly,ube3a,Ipp,gpr17,oca2,cog4,and atp10a)were significantly differentially expressed between the male and female groups.Furthermore,LD block analysis suggested that a cluster of genes on ChrLG23 may participate in regulating sex development in red tilapia.Our study provides important information on the genetic architecture of sex in red tilapia and should facilitate further exploration of sex determination mechanisms in this species.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

第三届华人光催化材料学术研讨会专刊前言

Photocatalytic materials have attracted more and more attention in the world due to their great potential in solar energy conversion and environmental remediation.We were honored to host the 3rd Chinese Symposium on Photocatalytic Materials(CSPM3)in Wuhan on December 11-14,2020,and hereby express our sincere thanks to all the guests and delegates attending this conference.

Airflow distribution law of multi-branch pipe of pneumatic rice direct seeder based on dimensional analysis

In order to investigate the flow characteristics and distribution law of airflow in multi-branch pipe of pneumatic rice precision direct seeder and obtain the mathematical model between airflow parameters and pipe geometry structure.In this study,the airflow flow law of the multi-branch pipeline of the pneumatic system was studied,the mechanism of airflow flow in the multi-branch pipe was analyzed,and it was clarified that the main factors affecting the airflow flow in the pipe,namely,air density,air dynamic viscosity,the total flow rate of the inlet branch pipe,the length of the closed end of the header,the inner diameter of the outlet branch pipe,and the outlet branch pipe spacing.Numerical simulations were carried out using Fluent simulation software to elucidate the cause of multi-branch pipes of uneven distribution of airflow in multi-branch pipes,the empirical equation among these factors and the flow velocity of the outlet branch pipe are established by dimensional analysis method.The bench test results show that the established empirical equations are applicable in the following ranges:0.018 m3/s≤Q≤0.054 m3/s,0.045 m≤d≤0.05 m,0.075 m≤L≤0.125 m,0.7 m≤Y 1≤0.875 m(0.5 m≤Y 2≤0.75 m,0.36 m≤Y 3≤0.45 m),the prediction accuracy can be controlled within 10%of the empirical formula,which can provide a reference for the prediction and optimization design of outlet velocity of the multi-branch pipe.

基于全同源策略构建低界面阻抗的柔性固态锂离子电池

固态锂离子电池被认为是可穿戴电子设备的理想储能器件.然而,高的电极/电解质界面阻抗仍是该领域一个严峻的挑战,尤其在弯曲变形条件下.本文提出全同源策略,利用热塑性聚氨酯作为固态电解质和电极的离子导电框架,构建具有低界面阻抗的柔性固态锂离子电池.实验结果表明,聚氨酯中-C=O、-NH和-C-O-C-等功能基团有助于锂离子传输.利用该特性,制备出具有高柔韧性和离子电导率的聚氨酯基固态电解质,以及具有优异柔韧性的复合电极,其即使在不同形变下仍能保持良好的电化学性能.在此基础上,成功组装了全同源的柔性固态锂离子电池,其表现出更低的界面阻抗和更优异的电化学性能.这种全同源策略为柔性固态电池的设计提供了一种新思路.

Role of feline ANP32 proteins in regulating polymerase activity of influenza A virus

Recently,increasing natural infection cases and experimental animal challenge studies demonstrated domestic cats are susceptible to multiple subtypes influenza A virus(IAV)infections.Notably,some subtype IAV strains could circulate in domestic cats after cross-species transmission and even infected humans,posing a threat to public health.Host factors related to viral polymerase activity could determine host range of IAV and acidic nuclear phosphoprotein 32(ANP32)is the most important one among them.However,role of cat-derived ANP32 on viral polymerase activity and host range of IAV is still unknown.In the present study,a total of 10 feline ANP32(feANP32)splice variants(including 5 feANP32A,3 feANP32B,and 2 feANP32E)were obtained from domestic cats by RT-PCR.Sequence alignment results demonstrated amino acid deletions and/or insertions occurred among feANP32 variants,but all feANP32 proteins were primarily localized to cell nucleus.Minigenome replication systems for several representative IAV strains were established and the support ability of feANP32 on IAV polymerase activity was estimated.The results indicated that most feANP32A and feANP32B splice variants were able to support all the tested IAV strains,though the support activity of a single feANP32 protein on polymerase activity varied among different IAV strains.In addition,the role of feANP32 in supporting H3N2 canine influenza virus was determined by investigating viral replication in vitro.Collectively,our study systematically investigated the support activity of feANP32 on IAV,providing a clue for further exploring the mechanism of susceptibility of cats to IAV.

Posture-invariant hybrid scaling weight measurement algorithm for live eels

To obtain higher economic benefits,large eel breeding companies classify live eels by weight.Due to their strong mobility and smooth body surface,living eels are not suitable for traditional mechanical weight measurement.In this study,a live eel sorting machine based on machine vision was developed,and a novel method was developed for obtaining live eel weight measurements through images.First,a backlit workbench was designed to capture static images of eels,and then the projection area and skeleton length of the images were obtained by image preprocessing.For the eel's body shape,which is generally cylindrical and gradually transitions to a flat tail,the tail posture changes affect the shape of the images;thus,a weight measurement model combining the projected area and the skeleton length was proposed.The optimal scale division coefficient of the weight model was found to be 0.745 by experimentation.Then,select eels of different weight ranges were used for model error verification and to obtain the correction function of the error.The weight gradient was used to confirm the corrected eel weight model.Finally,the system calculation results were compared with the actual measurement results.The root mean square error(RMSE)was 12.94 g,and the mean absolute percentage error(MAPE)was 2.12%.The results show that the proposed method provided a convenient,fast,and low-cost non-contact weight measurement method for live eels,reduced the damage rate of live eels,and can meet the technical requirements of actual production.

Design and experimental study of the fertilizer applicator with vertical spiral fluted rollers

To improve the uniformity and accuracy of fertilizing amount for fertilizer applicators with spiral fluted roller,this paper experimentally studied the influence of major structural parameters on the fertilizing performance.Through two sets of orthogonal tests,it is found that the helix angle and installation angle of spiral fluted rollers are the main factors,which affect the uniformity of fertilizer discharge and the linear relationship between fertilizing amount and opening,respectively.Based on these findings,the experiment and analysis were carried out to determine the optimal helix angle and installation angle for the spiral fluted roller The experimental results of fertilizing performance show that:when the helix angle is 45°,it able to achieve satisfactory uniformity of fertilizer discharge and linear relationship between fertilizing amount and rotational speed;when the installation angle is 40°,it enhances the accuracy of fertilizer discharge with good linear relationship between fertilizing amount and opening.Compared with the fertilizing performance of traditional fertilizer applicators with horizontally installed straight fluted roller,in the aspect of uniformity,the optimized fertilizer applicators reduce the variation coefficient of fertilizing amount within 0.2 s at low speed(10-30 r/min)from 5.1%-52.5%to 4.2%-14.7%;in the aspect of accuracy;and increase the correlation coefficient square R2 between fertilizing amount and opening from 0.93-0.97 to no less than 0.996,and the regression intercept in the fitting equation is reduced from larger than 10.0 to less than 1.0.

Antagonistic interaction between male-killing and cytoplasmic incompatibility induced by Cardinium and Wolbachia in the whitefly,Bemisia tabaci

Cardinium and Wolbachia are maternally inherited bacterial symbionts of arthropods that can manipulate host reproduction by increasing the fitness of infected females.Here,we report that Cardinium and Wolbachia coinfection induced male-killing and cytoplasmic incompatibility(CI)when they coexisted in a cryptic species of whitefly,Bemisia tabaci Asia II7.Cardinium and Wolbachia symbionts were either singly or simul-taneously localized in the bacteriocytes placed in the abdomen of B.tabaci nymphs and adults.Cardinium-Wolbachia coinfection induced male-killing and resulted in a higher female sex ratio in the intraspecific amphigenetic progeny of Asia II7 IcwH and IcwL lines;interestingly,male-illing induction was enhanced with increased Cardinium titer.Moreover,single infection of Wolbachia induced partial CI in the Asia II7 Iw line and resulted in reduced fecundity,higher embryonic mortality,and lower female sex ratio.The uninfected Asia II7 Iu line had significantly higher fecundity,lower embryonic and nymphal mortalities,and a lower level of CI than both the Wolbachia infected Asia II7 Iw line and the Cardinium--Wolbachia-coinfected Asia II7 IcwH line.Our findings indicate that Cardinium-Wolbachia coinfection induced male-killing,which may have had antag-onistic effects on Wolbachia-induced CI in the Asia II7 whiteflies.For the first time,our study revealed that B.tabaci Asia II7 reproduction is co-manipulated by Cardinium and Wolbachia endosymbionts.

内嵌碳点的无铅金属卤化物单晶用于单组分白光发射体

白光发光二极管(WLED)照明光源的发展对于降低能源消耗具有重要意义.然而,常用的基于荧光粉转换技术的WLED器件存在自吸收严重、显色指数低和稀土元素供应风险等多方面的不足.对此,本文通过组装蓝光碳点(CDs)和无铅黄光金属卤化物(Cs_(2)InCl_(5)·H_(2)O:Sb^(3+)),开发了一种新的单组分白光发射材料.采用液-液扩散辅助结晶方法,本工作成功地将CDs嵌入到Cs_(2)InCl_(5)·H_(2)O:Sb^(3+)晶体中,复合材料呈现出白光发射.调节CDs和Cs_(2)InCl_(5)·H_(2)O:Sb^(3+)的比例可实现冷/暖色调可调.使用这种“内嵌CDs的卤化物晶体”复合材料作为转换器,我们成功制造出单一体系WLED,其显色指数(CRI)高达93.6,为下一代室内高品质WLED照明光源提供了一种便捷有效的策略.

水文循环模拟中地形和土地利用覆被参数化方法综述（英文）

Numerous topography, land-cover, land-use, and soil-type parameterization methods are required to simulate the hydrologic cycle. In this paper, using the principles of hydrologic cycle simulation, 20 methods commonly applied to runoff-yield simulation are analyzed. Additionally, parameterization methods used in 17 runoff-yield simulation methods and 15 confluence methods are discussed, including the degree of parameterization. Next, the parameterization methods are classified into four categories: not clearly expressed; calibrated; deterministic; and physical–conceptual. Furthermore, we clarify responses and contributions of different parameterization methods to hydrologic cycle simulation results. Finally, major weaknesses of simplified descriptions of complex rational and physical mechanisms in the parameterization methods of the underlying surfaces in hydrologic models are outlined, and two directions of future development are estimated, looking toward simple practicality and complex mechanization.