Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts（DBPs） and toxicity. This study reviewed the formation and control...Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts（DBPs） and toxicity. This study reviewed the formation and control strategies for DBPs and toxicity in reclaimed water during chlorination.Both regulated and emerging DBPs have been frequently detected in reclaimed water during chlorination at a higher level than those in drinking water, indicating they pose a greater risk to humans. Luminescent bacteria and Daphnia magna acute toxicity, anti-estrogenic activity and cytotoxicity generally increased after chlorination because of the formation of DBPs. Genotoxicity by umu-test and estrogenic activity were decreased after chlorination because of destruction of toxic chemicals. During chlorination, water quality significantly impacted changes in toxicity.Ammonium tended to attenuate toxicity changes by reacting with chlorine to form chloramine,while bromide tended to aggravate toxicity changes by forming hypobromous acid. During pretreatment by ozonation and coagulation, disinfection byproduct formation potential（DBPFP）and toxicity formation potential（TFP） occasionally increase, which is accompanied by DOC removal; thus, the decrease of DOC was limited to indicate the decrease of DBPFP and TFP. It is more important to eliminate the key fraction of precursors such as hydrophobic acid and hydrophilic neutrals. During chlorination, toxicities can increase with the increasing chlorine dose and contact time. To control the excessive toxicity formation, a relatively low chlorine dose and short contact time were required. Quenching chlorine residual with reductive reagents also effectively abated the formation of toxic compounds.展开更多
Objective:To identify members of genera of rickettsia and O.tsutsugammhi simultaneously.Methods:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved regions of heat...Objective:To identify members of genera of rickettsia and O.tsutsugammhi simultaneously.Methods:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved regions of heat shock protein GroEL gene.345 mouse viscera samples including liver,spleen and kidney,96 Xenopsylla cheopis and 32 chiggers collected from Hongta areas of Yuxi city,Yunnan province were tested by the new PCR methods.Results:The result of the study showed that the new PCR methods could identify most members of genera -Rickettsia and Orientia simultaneously with 100%specificity and its sensitivity could test one copy per microliter.The results of detection prevalence of rickettsioses in mouse,flea and mites DNA samples showed that the total rickettsia infection rate in mouse was 34.78%(120/345).The total infection rates in R.typhi,O.t Karp and R.sibirica of mouse samples were 28.12%(97/345),19.71%(68/345) and O. 29%(1/345) respectively.Co-infection rates in R.typhi and 0.t Karp of mouse samples were 13.33%(46/ 345).O.t Karp type has been the main epidemic strain in these areas.Conclusion:We concluded that this PCR method could be used to detect multi-genera rickettsia simultaneously.Molecular evidences provided in this and previous studies strongly support that Hongta areas of Yuxi city are a natural focus for typhus and scrub typhus with the common occurrence of their confection.展开更多
Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the ch...Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the change of its molecular structure has not been well developed yet. In this study, the RO membrane fouling behavior of humic acid was studied systematically with ozonation as a pretreatment method to control RO membrane fouling. Furthermore, the effect of ozone on the structure ofhumic acid was also explored to reveal the mechanisms. Humic acid alone (10-90 mg/L, in deionized water) was found not to cause obvious RO membrane fouling in 45-h operation. However, the presence of Ca^2+ aggravated significantly the RO membrane fouling caused by humic acid, with significant flux reduction and denser fouling layer on RO membrane, as it was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). However, after the pretreatment by ozone, the influence of Ca^2+ was almost eliminated. Further analysis revealed that the addition of Ca^2+ increased the particle size of humic acid solution significantly, while ozonation reduced the SUVA254, particle size and molecular weight of the complexes of humic acid and Ca^2+(HA-Ca^2+ complexes). According to these results and literature, the bridge effect of Ca^2+ aggregating humic acid molecules and the cleavage effect of ozone breaking HA-Ca^2+ complexes were summarized. The change of the structure of humic acid under the effect of Ca^2+ and ozone is closely related to the change of its membrane fouling behavior.展开更多
Antibacterial resistance is a global health threat that requires further concrete action on the part of all countries.In this context,one of the biggest concerns is whether enough new antibacterial drugs are being dis...Antibacterial resistance is a global health threat that requires further concrete action on the part of all countries.In this context,one of the biggest concerns is whether enough new antibacterial drugs are being discovered and developed.Although several high-quality reviews on clinical antibacterial drug pipelines from a global perspective were published recently,none provides comprehensive information on original antibacterial drugs at clinical stages in China.In this review,we summarize the latest progress of novel antibacterial drugs approved for marketing and under clinical evaluation in China since 2019.Information was obtained by consulting official websites,searching commercial databases,retrieving literature,asking personnel from institutions or companies,and other means,and a considerable part of the data covered here has not been included in other reviews.As of June 30,2023,a total of 20 antibacterial projects from 17 Chinese pharmaceutical companies or developers were identified and updated.Among them,two new antibacterial drugs that belong to traditional antibiotic classes were approved by the National Medical Products Administration(NMPA)in China in 2019 and 2021,respectively,and 18 antibacterial agents are in clinical development,with one under regulatory evaluation,five in phase-3,six in phase-2,and six in phase-1.Most of the clinical candidates are new analogs or monocomponents of traditional antibacterial pharmacophore types,including two dual-acting hybrid antibiotics and a recombinant antibacterial protein.Overall,despite there being 17 antibacterial clinical candidates,our analysis indicates that there are still relatively few clinically differentiated antibacterial agents in stages of clinical development in China.Hopefully,Chinese pharmaceutical companies and institutions will develop more innovative and clinically differentiated candidates with good market potential in the future research and development(R&D)of original antibacterial drugs.展开更多
In this work,LED-based photocatalysis using mixed rutile and anatase phase TiO_(2)(P25)as the photocatalyst could effectively remove 5-chloro-2-methyl-4-isothiazolin-3-one(CMIT)and methylisothiazolone(MIT)simultaneous...In this work,LED-based photocatalysis using mixed rutile and anatase phase TiO_(2)(P25)as the photocatalyst could effectively remove 5-chloro-2-methyl-4-isothiazolin-3-one(CMIT)and methylisothiazolone(MIT)simultaneously,with removal efficiencies above 80%within 20 min.The photocatalytic degradation of both CMIT and MIT could be modeled using a pseudo-first-order rate equation.The photocatalytic degradation rates of CMIT and MIT under LED280 illumination were higher than under LED310 or LED360 illumination.At concentrations below 100 mg/L,the degradation rate of CMIT and MIT under LED illumination significantly increased with increasing catalyst dosage.Additionally,the effects of the chloride ion concentration,alkalinity and dissolved organic matter on the photocatalytic degradation reaction were also investigated.The·OH free radicals were determined to play the primary role in the photocatalytic degradation reaction,with a degradation contribution of>95%.The photocatalytic degradation of CMIT and MIT mainly occurred via oxidation,hydrolysis,and chain growth reactions.Finally,the possible photocatalytic degradation pathways of CMIT and MIT over LED/P25 are proposed.展开更多
Chlorination,the most widely used disinfection process for water treatment,is unfortunately always accompanied with the formation of hazardous disinfection byproducts(DBPs).Various organic matter species,like natural ...Chlorination,the most widely used disinfection process for water treatment,is unfortunately always accompanied with the formation of hazardous disinfection byproducts(DBPs).Various organic matter species,like natural organic matter(NOM)and amino acids,can serve as precursors of DBPs during chlorination but it is not clear what types of organic matter have higher potential risks.Although regulation of DBPs such as trihalomethanes has received much attention,further investigation of the DBPs driving toxicity is required.This study aimed to identify the important precursors of chlorination by measuring DBP formation from NOM and amino acids,and to determine the main DBPs driving toxicity using a theoretical toxicity evaluation of contributions to the cytotoxicity index(CTI)and genotoxicity index(GTI).The results showed that NOM mainly formed carbonaceous DBPs(CDBPs),such as trichloromethane,while amino acids mainly formed nitrogenous DBPs(N-DBPs),such as dichloroacetonitrile(DCAN).Among the DBPs,DCAN had the largest contribution to the toxicity index and might be the main driver of toxicity.Among the precursors,aspartic acid and asparagine gave the highest DCAN concentration(200 g/L)and the highest CTI and GTI.Therefore,aspartic acid and asparagine are important precursors for toxicity and their concentrations should be reduced as much as possible before chlorination to minimize the formation of DBPs.During chlorination of NOM,tryptophan,and asparagine solutions with different chlorine doses and reaction times,changes in the CTI and GTI were consistent with changes in the DCAN concentration.展开更多
Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light absorbance.In this study...Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light absorbance.In this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called AgUTCN.The Ag hardly changed the carbon nitride's layered and porous physical structure.AgUTCN exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for 1hr.Doping with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair recombination.In addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).展开更多
Apart from mediating viral entry,the function of the free HIV-1 envelope protein(gp120)has yet to be elucidated.Our group previously showed that EP2 derived from oneβ-strand in gp120 can form amyloid fibrils that inc...Apart from mediating viral entry,the function of the free HIV-1 envelope protein(gp120)has yet to be elucidated.Our group previously showed that EP2 derived from oneβ-strand in gp120 can form amyloid fibrils that increase HIV-1 infectivity.Importantly,gp120 contains~30β-strands.We examined whether gp120 might serve as a precursor protein for the proteolytic release of amyloidogenic fragments that form amyloid fibrils,thereby promoting viral infection.Peptide array scanning,enzyme degradation assays,and viral infection experiments in vitro confirmed that manyβ-stranded peptides derived from gp120 can indeed form amyloid fibrils that increase HIV-1 infectivity.These gp120-derived amyloidogenic peptides,or GAPs,which were confirmed to form amyloid fibrils,were termed gp120-derived enhancers of viral infection(GEVIs).GEVIs specifically capture HIV-1 virions and promote their attachment to target cells,thereby increasing HIV-1 infectivity.Different GAPs can cross-interact to form heterogeneous fibrils that retain the ability to increase HIV-1 infectivity.GEVIs even suppressed the antiviral activity of a panel of antiretroviral agents.Notably,endogenous GAPs and GEVIs were found in the lymphatic fluid,lymph nodes,and cerebrospinal fluid(CSF)of AIDS patients in vivo.Overall,gp120-derived amyloid fibrils might play a crucial role in the process of HIV-1 infectivity and thus represent novel targets for anti-HIV therapeutics.展开更多
To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfa...To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfanghong For-est that varied in thinning intensity:plot A(10%),B(15%),C(20%),D(25%),E(30%),F(35%),and the control sample area(0%).A principal component analysis was performed using 50 different variables,including species diversity,soil fertility,litter characteristics,canopy structure param-eters,and seedling regeneration parameters.The effects of thinning intensity on carbon sequestration were strongest in plot E(0.75),followed by D(0.63),F(0.50),C(0.48),B(0.22),A(0.11),and the control(0.06).The composite score of plot E was the highest,indicating that the carbon sequestration effect was strongest at a thinning intensity of 30%.These findings provide useful insights that could aid the management of natural mixed coniferous and broadleaf forests in Xiaoxing’an Mountains,China.This information has implications for future studies of these forests,and the methods used could aid future ecological assessments of the natural forests in Xiaoxing’an Mountains,China.展开更多
Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulati...Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulations can cause significant harm to agricultural production, the environment, and non-target species. This study evaluated the cytotoxicity and oxidative stress of a seized formulation containing the herbicide imazethapyr (IMZT). Characterization of the herbicide included gas chromatography-mass spectrometry (GC-MS) and thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). Hemolytic and cytotoxicity assays in ZF-L hepatic cells showed IC50 values of 12.75 µg/mL, 3.01 µg/mL, 2.67 µg/mL, and 1.61 µg/mL for erythrocytes, [3(4,5-dimethyl)-2 bromide-5 diphenyl tetrazolium] (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays, respectively. The median IC50 of 2.84 µg/mL was used in oxidative stress assays, revealing increased reactive oxygen species (ROS) production, reduced total sulfhydryl content, and decreased superoxide dismutase (SOD) and catalase (CAT) activity. This study is the first to report in vitro oxidative stress induced by IMZT in the ZF-L cell line, emphasizing the importance of in vitro assays for assessing the toxic effects of seized agrochemicals on human health and the environment.展开更多
Harmful cyanobacterial blooms(HCBs)pose a global ecological threat.Ultraviolet C(UVC)irradiation at 254 nm is a promising method for controlling cyanobacterial proliferation,but the growth suppression is temporary.Res...Harmful cyanobacterial blooms(HCBs)pose a global ecological threat.Ultraviolet C(UVC)irradiation at 254 nm is a promising method for controlling cyanobacterial proliferation,but the growth suppression is temporary.Resuscitation remains a challenge with UVC application,necessitating alternative strategies for lethal effects.Here,we show synergistic inhibition of Microcystis aeruginosa using ultraviolet A(UVA)pre-irradiation before UVC.We find that low-dosage UVA pre-irradiation(1.5 J cm^(−2))combined with UVC(0.085 J cm^(−2))reduces 85%more cell densities compared to UVC alone(0.085 J cm^(−2))and triggers mazEF-mediated regulated cell death(RCD),which led to cell lysis,while high-dosage UVA pre-irradiations(7.5 and 14.7 J cm^(−2))increase cell densities by 75-155%.Our oxygen evolution tests and transcriptomic analysis indicate that UVA pre-irradiation damages photosystem I(PSI)and,when combined with UVC-induced PSII damage,synergistically inhibits photosynthesis.However,higher UVA dosages activate the SOS response,facilitating the repair of UVC-induced DNA damage.This study highlights the impact of UVA pre-irradiation on UVC suppression of cyanobacteria and proposes a practical strategy for improved HCBs control.展开更多
Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic...Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for Escherichia coli （E. coli） CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet （UV） or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene blaTEM-1 was assessed. We reported a greater stability in ampicillinresistant E. coli CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other E. coli strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant E. coli when subse-quently exposed to ampicillin. The ampicillin hemiinhibitory concentration （IC5o） without disinfection was 3800mg·L^-1, and an increment was observed after UV irradiation or chlorination. The IC50 of ampicillin-resistant E. coli was 1.5-fold higher at a UV dose of 40 mJ·cm^-2, and was 1.4-fold higher when exposed to 2.0 mg·L^-1 chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for E. coli strains with high ampicillin resistance. There was no evident damage to blaTEM-1 after 1-10 mg Cl2· L^-1 chlorination, while a UV dose of 80 mJ·cm^-2 yielded a damage ratio for blaTEM-1 of approximately 1.2-log.Therefore, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.展开更多
As water reuse development has increased,biological stability issues associated with reclaimed water have gained attention.This study evaluated assimilable organic carbon(AOC)in effluents from a full-scale membrane bi...As water reuse development has increased,biological stability issues associated with reclaimed water have gained attention.This study evaluated assimilable organic carbon(AOC)in effluents from a full-scale membrane biological reactor(MBR)plant and found that they were generally stable over one year(125-216µg/L),with slight increases in warmer seasons.After additional tertiary treatments,the largest increases in absolute and specific AOCs were detected during ozonation,followed by coagulation-ozonation and coagulation.Moreover,UV254 absorbance is known to be an effective surrogate to predict the AOC changes during ozonation.Applying coagulation prior to ozonation of MBR effluents for removal of large molecules was found to reduce the AOC formation compared with ozonation treatment alone.Finally,the results revealed that attention should be paid to seasonal variations in influent and organic fraction changes during treatment to enable sustainable water reuse.展开更多
The risks posed by algal blooms caused by nitrogen and phosphorus in reclaimed water used in urban water landscapes need to be carefully controlled.In this study,the combined effects of the nitrogen and phosphorus con...The risks posed by algal blooms caused by nitrogen and phosphorus in reclaimed water used in urban water landscapes need to be carefully controlled.In this study,the combined effects of the nitrogen and phosphorus concentrations and the light intensity and temperature on the specific growth rates of algae were determined using Monod,Steele,and Arrhenius models,then an integrated algal growth model was developed.The algae biomass,nitrogen concentration,and phosphorus concentration mass balance equations were used to establish a new control model describing the nitrogen and phosphorus concentration and hydraulic retention time thresholds for algal blooms.The model parameters were determined by fitting the models to data acquired experimentally.Finally,the control model and numerical simulations for six typical algae and mixed algae under standard conditions were used to determine nitrogen/phosphorus concentration and hydraulic retention time thresholds for landscape water to which reclaimed water is supplied(i.e.,for a reclaimed water landscape).展开更多
Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading...Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter（DOM） was investigated in this study. Solar light significantly decreased the UV_（254） absorbance and fluorescence（FLU） intensity of reclaimed water.However, its effect on the dissolved organic carbon（DOC） value of reclaimed water was very limited. The decrease in the UV_（254） absorbance intensity and FLU excitation–emission matrix regional integration volume（FLU volume） of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV_（254） absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV_（254） absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV_（254） and FLU intensity were independent of light intensity. The peaks of the UV_（254） absorbance and FLU intensity with an apparent molecular weight（AMW） of 100 Da to 2000 Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change.展开更多
Background Although severe acute respiratory syndrome （SARS） has been controlled, the subsequently emerging sporadic cases in 2004 emphasize the necessity of developing a rapid diagnostic method, which would be of g...Background Although severe acute respiratory syndrome （SARS） has been controlled, the subsequently emerging sporadic cases in 2004 emphasize the necessity of developing a rapid diagnostic method, which would be of great help in clinical diagosis and also wild host screening. This study aims to establish an effective and rapid serological tool for the diagnosis of SARS-CoV by comparison among whole viral, N and N199 proteins by ELISA. Methods SARS-CoV N and N199 （a truncated nucleocapsid gene） genes were cloned, expressed, identified by Western blotting, and applied in screening of human and swine samples. Sera of SARS convalescent-phase patients, normal human sera, sera of patients with other respiratory diseases, and swine sera were screened by ELISA, with whole SARS-CoV F69, N and N199 proteins as antigens. Results The sensitivity and specificity of N and N199 proteins in human sera diagnosis were approximate （P=-0.743）, which was higher than whole viral protein but the difference was not significant （P=-0.234）. The N199 protein proved to be more specific in swine sera screening than whole viral and N protein （P〈0.001）. Conclusion N199 protein is feasible in both clinical diagnosis and SARS-CoV reservoir screening.展开更多
In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most...In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.展开更多
Impact statement Nonhuman primates(NHPs)such as monkeys are the closest living relatives to humans and are the best available models for causative studies of human health and diseases.Gut microbiomes are intensively i...Impact statement Nonhuman primates(NHPs)such as monkeys are the closest living relatives to humans and are the best available models for causative studies of human health and diseases.Gut microbiomes are intensively involved in host health.In this study,by large-scale cultivation of microbes from fecal samples of monkeys,we obtained previously uncultured bacterial species and constructed a Macaca fascicularis Gut Microbial Biobank(MfGMB).The MfGMB consisted of 250 strains that represent 97 species of 63 genera,25 families,and 4 phyla.The information of the 250 strains and the genomes of 97 cultured species are publicly accessible.The MfGMB represented nearly 50% of core gut microbial compositions at the genus level and covered over 80% of the KO-based known gut microbiome functions of M.fascicularis.Data mining showed that the bacterial species in the MfGMB were prevalent not only in NHPs gut microbiomes but also in human gut microbiomes.This study will help the understanding and future investigations on how gut microbiomes interact with their mammalian hosts.展开更多
The aim of this study was to investigate the distribution, density, community structure and biodiversity characteristics of benthic diatoms, and to analyze whether differences in species composition and abundance exis...The aim of this study was to investigate the distribution, density, community structure and biodiversity characteristics of benthic diatoms, and to analyze whether differences in species composition and abundance exist in different regions of the Niyang River, Tibet. Among the 157 taxa observed in 15 sampling sites in the main river and tributary, most were casual species （〉100）, the relative abundance of the genera Achnantkes and Fragilaria was 67% of the total relative abundance. Acknantkes minutissima was the most important species and dominated the whole river reaches （average relative abundance was 30%）; the average diatom densities were 7.4 x 105 cell/cm2 at all sites, and increased slowly from the upper section to downriver. The significant indicator taxa with higher relative abundance were Achnanthes biasolettiana （18.0%） and Fragilaria arcus （18.2%）, Fragilaria capucina var. vaucheriae （31.2%）, Fragilaria construens var. renter （11.3%） and Cymbella affinis （11.0%） in the upper, tributary and mid-river sections, respectively. Achnanthes minutissima was the most abundant species （56%） in the downriver section. Biodiversity indices showed a gradual decrease from the up- to down-river section, and dominant species were more abundant in the upper and mid-river sections than in the downriver section. A two-way indictor species analysis （TWINSPAN） of diatom composition clearly showed four different groups, namely the upper, mid, lower and tributary sections. Detrended correspondence analysis （DCA） supported the results of TW1NSPAN, and the characteristics of site distribution and species composition in the Niyang River supported the spatial structure of diatom assemblages. This study indicates that bio-assessment programs utilizing benthic diatoms could clearly benefit lotic water with regional stratification.展开更多
A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand＆ plantations in the semiarid region （ 15&#...A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand＆ plantations in the semiarid region （ 15° 09′ S 43° 49′ W） in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass （dry matter） was 33.6 Mg.ha^-1 for E. camaldulensis and 53.1 Mg·ha^-1 for E. grandis. The biomass of the stem wood, leaves, branches, and stein bark for E. camaldulens accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively （Table 2）; meanwhile a similar partition of the total above-ground biomass was also found for E. grand＆. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk （bark and wood）, nutrient accumulation in general was lower. Nutrient content of E. grand＆ presented little variation compared with that orE. camaJd^llensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grand＆. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy.展开更多
基金funded by the National Natural Science Foundation of China (Nos.51578308, 51678332)the International S&T Cooperation Program of China (ISTCP) (No.S2016G6030)+2 种基金the National Water Pollution Control and Treatment Science and Technology Major Project (No.20122X07302002)the Shenzhen Science, Technology and Innovation Commission (No.JCYJ20160125095838752)the Collaborative Innovation Center for Regional Environmental Quality
文摘Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts（DBPs） and toxicity. This study reviewed the formation and control strategies for DBPs and toxicity in reclaimed water during chlorination.Both regulated and emerging DBPs have been frequently detected in reclaimed water during chlorination at a higher level than those in drinking water, indicating they pose a greater risk to humans. Luminescent bacteria and Daphnia magna acute toxicity, anti-estrogenic activity and cytotoxicity generally increased after chlorination because of the formation of DBPs. Genotoxicity by umu-test and estrogenic activity were decreased after chlorination because of destruction of toxic chemicals. During chlorination, water quality significantly impacted changes in toxicity.Ammonium tended to attenuate toxicity changes by reacting with chlorine to form chloramine,while bromide tended to aggravate toxicity changes by forming hypobromous acid. During pretreatment by ozonation and coagulation, disinfection byproduct formation potential（DBPFP）and toxicity formation potential（TFP） occasionally increase, which is accompanied by DOC removal; thus, the decrease of DOC was limited to indicate the decrease of DBPFP and TFP. It is more important to eliminate the key fraction of precursors such as hydrophobic acid and hydrophilic neutrals. During chlorination, toxicities can increase with the increasing chlorine dose and contact time. To control the excessive toxicity formation, a relatively low chlorine dose and short contact time were required. Quenching chlorine residual with reductive reagents also effectively abated the formation of toxic compounds.
基金supported by National Natural Science Foundation of China(No. 30771854)China-U.S.Collaborative Program on Emerging and Re-emerging Infectious Diseases(No. 1U2GGH000018-01)
文摘Objective:To identify members of genera of rickettsia and O.tsutsugammhi simultaneously.Methods:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved regions of heat shock protein GroEL gene.345 mouse viscera samples including liver,spleen and kidney,96 Xenopsylla cheopis and 32 chiggers collected from Hongta areas of Yuxi city,Yunnan province were tested by the new PCR methods.Results:The result of the study showed that the new PCR methods could identify most members of genera -Rickettsia and Orientia simultaneously with 100%specificity and its sensitivity could test one copy per microliter.The results of detection prevalence of rickettsioses in mouse,flea and mites DNA samples showed that the total rickettsia infection rate in mouse was 34.78%(120/345).The total infection rates in R.typhi,O.t Karp and R.sibirica of mouse samples were 28.12%(97/345),19.71%(68/345) and O. 29%(1/345) respectively.Co-infection rates in R.typhi and 0.t Karp of mouse samples were 13.33%(46/ 345).O.t Karp type has been the main epidemic strain in these areas.Conclusion:We concluded that this PCR method could be used to detect multi-genera rickettsia simultaneously.Molecular evidences provided in this and previous studies strongly support that Hongta areas of Yuxi city are a natural focus for typhus and scrub typhus with the common occurrence of their confection.
基金funded by the National Key Research and Development Program of China (Grant No. 2016YFE0118800)Key Program of the National Natural Science Foundation of China (No.51738005).
文摘Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the change of its molecular structure has not been well developed yet. In this study, the RO membrane fouling behavior of humic acid was studied systematically with ozonation as a pretreatment method to control RO membrane fouling. Furthermore, the effect of ozone on the structure ofhumic acid was also explored to reveal the mechanisms. Humic acid alone (10-90 mg/L, in deionized water) was found not to cause obvious RO membrane fouling in 45-h operation. However, the presence of Ca^2+ aggravated significantly the RO membrane fouling caused by humic acid, with significant flux reduction and denser fouling layer on RO membrane, as it was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). However, after the pretreatment by ozone, the influence of Ca^2+ was almost eliminated. Further analysis revealed that the addition of Ca^2+ increased the particle size of humic acid solution significantly, while ozonation reduced the SUVA254, particle size and molecular weight of the complexes of humic acid and Ca^2+(HA-Ca^2+ complexes). According to these results and literature, the bridge effect of Ca^2+ aggregating humic acid molecules and the cleavage effect of ozone breaking HA-Ca^2+ complexes were summarized. The change of the structure of humic acid under the effect of Ca^2+ and ozone is closely related to the change of its membrane fouling behavior.
基金supported by the National Natural Science Foundation of China(32141003 and 82330110)the CAMS Innovation Fund for Medical Sciences(CIFMS+2 种基金2021-I2M-1-039)the National Science and Technology Infrastructure of China(National Pathogen Resource Center-NPRC-32)the Fundamental Research Funds for the Central Universities(2021-PT350-001).
文摘Antibacterial resistance is a global health threat that requires further concrete action on the part of all countries.In this context,one of the biggest concerns is whether enough new antibacterial drugs are being discovered and developed.Although several high-quality reviews on clinical antibacterial drug pipelines from a global perspective were published recently,none provides comprehensive information on original antibacterial drugs at clinical stages in China.In this review,we summarize the latest progress of novel antibacterial drugs approved for marketing and under clinical evaluation in China since 2019.Information was obtained by consulting official websites,searching commercial databases,retrieving literature,asking personnel from institutions or companies,and other means,and a considerable part of the data covered here has not been included in other reviews.As of June 30,2023,a total of 20 antibacterial projects from 17 Chinese pharmaceutical companies or developers were identified and updated.Among them,two new antibacterial drugs that belong to traditional antibiotic classes were approved by the National Medical Products Administration(NMPA)in China in 2019 and 2021,respectively,and 18 antibacterial agents are in clinical development,with one under regulatory evaluation,five in phase-3,six in phase-2,and six in phase-1.Most of the clinical candidates are new analogs or monocomponents of traditional antibacterial pharmacophore types,including two dual-acting hybrid antibiotics and a recombinant antibacterial protein.Overall,despite there being 17 antibacterial clinical candidates,our analysis indicates that there are still relatively few clinically differentiated antibacterial agents in stages of clinical development in China.Hopefully,Chinese pharmaceutical companies and institutions will develop more innovative and clinically differentiated candidates with good market potential in the future research and development(R&D)of original antibacterial drugs.
基金the Major Science and Technology Program for Water Pollution Control and Treatment,China(No.2017ZX07205001)the Shenzhen Science and Technology Innovation Commission(No.JCYJ20160125095838752)the Development and Reform Commission of Shenzhen Municipality(Urban Water Recycling and EnvironmentSafety Program).
文摘In this work,LED-based photocatalysis using mixed rutile and anatase phase TiO_(2)(P25)as the photocatalyst could effectively remove 5-chloro-2-methyl-4-isothiazolin-3-one(CMIT)and methylisothiazolone(MIT)simultaneously,with removal efficiencies above 80%within 20 min.The photocatalytic degradation of both CMIT and MIT could be modeled using a pseudo-first-order rate equation.The photocatalytic degradation rates of CMIT and MIT under LED280 illumination were higher than under LED310 or LED360 illumination.At concentrations below 100 mg/L,the degradation rate of CMIT and MIT under LED illumination significantly increased with increasing catalyst dosage.Additionally,the effects of the chloride ion concentration,alkalinity and dissolved organic matter on the photocatalytic degradation reaction were also investigated.The·OH free radicals were determined to play the primary role in the photocatalytic degradation reaction,with a degradation contribution of>95%.The photocatalytic degradation of CMIT and MIT mainly occurred via oxidation,hydrolysis,and chain growth reactions.Finally,the possible photocatalytic degradation pathways of CMIT and MIT over LED/P25 are proposed.
基金the National Natural Science Foundation of China(Grant No.51678332 and 51738005)the Shenzhen Science,Technology and Innovation Commission(Grant No.JCYJ20170818091859147)+1 种基金the special support program for high-level personnel recruitment in Guangdong Province(Grant No.2016TQ03Z384)the Development and Reform Commission of Shenzhen Municipality.
文摘Chlorination,the most widely used disinfection process for water treatment,is unfortunately always accompanied with the formation of hazardous disinfection byproducts(DBPs).Various organic matter species,like natural organic matter(NOM)and amino acids,can serve as precursors of DBPs during chlorination but it is not clear what types of organic matter have higher potential risks.Although regulation of DBPs such as trihalomethanes has received much attention,further investigation of the DBPs driving toxicity is required.This study aimed to identify the important precursors of chlorination by measuring DBP formation from NOM and amino acids,and to determine the main DBPs driving toxicity using a theoretical toxicity evaluation of contributions to the cytotoxicity index(CTI)and genotoxicity index(GTI).The results showed that NOM mainly formed carbonaceous DBPs(CDBPs),such as trichloromethane,while amino acids mainly formed nitrogenous DBPs(N-DBPs),such as dichloroacetonitrile(DCAN).Among the DBPs,DCAN had the largest contribution to the toxicity index and might be the main driver of toxicity.Among the precursors,aspartic acid and asparagine gave the highest DCAN concentration(200 g/L)and the highest CTI and GTI.Therefore,aspartic acid and asparagine are important precursors for toxicity and their concentrations should be reduced as much as possible before chlorination to minimize the formation of DBPs.During chlorination of NOM,tryptophan,and asparagine solutions with different chlorine doses and reaction times,changes in the CTI and GTI were consistent with changes in the DCAN concentration.
基金supported by the Shenzhen Science,Technology and Innovation Commission(No.JCYJ20200109142829123)the National Natural Science Foundation of China(No.52022049)。
文摘Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light absorbance.In this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called AgUTCN.The Ag hardly changed the carbon nitride's layered and porous physical structure.AgUTCN exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for 1hr.Doping with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair recombination.In addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).
基金supported by grants from the Natural Science Foundation of China(82072276 and 81772194 to ST,82073898 and 31370781 to SL,and 81630090 to SJ).
文摘Apart from mediating viral entry,the function of the free HIV-1 envelope protein(gp120)has yet to be elucidated.Our group previously showed that EP2 derived from oneβ-strand in gp120 can form amyloid fibrils that increase HIV-1 infectivity.Importantly,gp120 contains~30β-strands.We examined whether gp120 might serve as a precursor protein for the proteolytic release of amyloidogenic fragments that form amyloid fibrils,thereby promoting viral infection.Peptide array scanning,enzyme degradation assays,and viral infection experiments in vitro confirmed that manyβ-stranded peptides derived from gp120 can indeed form amyloid fibrils that increase HIV-1 infectivity.These gp120-derived amyloidogenic peptides,or GAPs,which were confirmed to form amyloid fibrils,were termed gp120-derived enhancers of viral infection(GEVIs).GEVIs specifically capture HIV-1 virions and promote their attachment to target cells,thereby increasing HIV-1 infectivity.Different GAPs can cross-interact to form heterogeneous fibrils that retain the ability to increase HIV-1 infectivity.GEVIs even suppressed the antiviral activity of a panel of antiretroviral agents.Notably,endogenous GAPs and GEVIs were found in the lymphatic fluid,lymph nodes,and cerebrospinal fluid(CSF)of AIDS patients in vivo.Overall,gp120-derived amyloid fibrils might play a crucial role in the process of HIV-1 infectivity and thus represent novel targets for anti-HIV therapeutics.
基金funded by National Key Research and development project(2022YFD2201001)Project for Applied TechnologyResearch and Development in Heilongjiang Province(GA19C006).
文摘To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfanghong For-est that varied in thinning intensity:plot A(10%),B(15%),C(20%),D(25%),E(30%),F(35%),and the control sample area(0%).A principal component analysis was performed using 50 different variables,including species diversity,soil fertility,litter characteristics,canopy structure param-eters,and seedling regeneration parameters.The effects of thinning intensity on carbon sequestration were strongest in plot E(0.75),followed by D(0.63),F(0.50),C(0.48),B(0.22),A(0.11),and the control(0.06).The composite score of plot E was the highest,indicating that the carbon sequestration effect was strongest at a thinning intensity of 30%.These findings provide useful insights that could aid the management of natural mixed coniferous and broadleaf forests in Xiaoxing’an Mountains,China.This information has implications for future studies of these forests,and the methods used could aid future ecological assessments of the natural forests in Xiaoxing’an Mountains,China.
文摘Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulations can cause significant harm to agricultural production, the environment, and non-target species. This study evaluated the cytotoxicity and oxidative stress of a seized formulation containing the herbicide imazethapyr (IMZT). Characterization of the herbicide included gas chromatography-mass spectrometry (GC-MS) and thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). Hemolytic and cytotoxicity assays in ZF-L hepatic cells showed IC50 values of 12.75 µg/mL, 3.01 µg/mL, 2.67 µg/mL, and 1.61 µg/mL for erythrocytes, [3(4,5-dimethyl)-2 bromide-5 diphenyl tetrazolium] (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays, respectively. The median IC50 of 2.84 µg/mL was used in oxidative stress assays, revealing increased reactive oxygen species (ROS) production, reduced total sulfhydryl content, and decreased superoxide dismutase (SOD) and catalase (CAT) activity. This study is the first to report in vitro oxidative stress induced by IMZT in the ZF-L cell line, emphasizing the importance of in vitro assays for assessing the toxic effects of seized agrochemicals on human health and the environment.
基金National Natural Science Foundation of China(52070117)Research Projects from Shenzhen Municipal Science and Technology Innovation Council(WDZC20200819163549002,JCYJ20200109142822787)+1 种基金Guangdong Higher Education Institutions Innovative Research Team of Urban Water Cycle and Ecological Safety,China(2023KCXTD053)Shenzhen Science and Technology Program,China(ZDSYS20220606100806014).
文摘Harmful cyanobacterial blooms(HCBs)pose a global ecological threat.Ultraviolet C(UVC)irradiation at 254 nm is a promising method for controlling cyanobacterial proliferation,but the growth suppression is temporary.Resuscitation remains a challenge with UVC application,necessitating alternative strategies for lethal effects.Here,we show synergistic inhibition of Microcystis aeruginosa using ultraviolet A(UVA)pre-irradiation before UVC.We find that low-dosage UVA pre-irradiation(1.5 J cm^(−2))combined with UVC(0.085 J cm^(−2))reduces 85%more cell densities compared to UVC alone(0.085 J cm^(−2))and triggers mazEF-mediated regulated cell death(RCD),which led to cell lysis,while high-dosage UVA pre-irradiations(7.5 and 14.7 J cm^(−2))increase cell densities by 75-155%.Our oxygen evolution tests and transcriptomic analysis indicate that UVA pre-irradiation damages photosystem I(PSI)and,when combined with UVC-induced PSII damage,synergistically inhibits photosynthesis.However,higher UVA dosages activate the SOS response,facilitating the repair of UVC-induced DNA damage.This study highlights the impact of UVA pre-irradiation on UVC suppression of cyanobacteria and proposes a practical strategy for improved HCBs control.
基金The author thanks the National Natural Science Foundation of China （Key Project, Grant No. 51138006） and State Key Joint Laboratory of Environment Simulation and Pollution Control （Project, No. 13L01ESPC） for financial support. The research is also supported by the Collaborative Innovation Center for Regional Environmental Quality.
文摘Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for Escherichia coli （E. coli） CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet （UV） or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene blaTEM-1 was assessed. We reported a greater stability in ampicillinresistant E. coli CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other E. coli strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant E. coli when subse-quently exposed to ampicillin. The ampicillin hemiinhibitory concentration （IC5o） without disinfection was 3800mg·L^-1, and an increment was observed after UV irradiation or chlorination. The IC50 of ampicillin-resistant E. coli was 1.5-fold higher at a UV dose of 40 mJ·cm^-2, and was 1.4-fold higher when exposed to 2.0 mg·L^-1 chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for E. coli strains with high ampicillin resistance. There was no evident damage to blaTEM-1 after 1-10 mg Cl2· L^-1 chlorination, while a UV dose of 80 mJ·cm^-2 yielded a damage ratio for blaTEM-1 of approximately 1.2-log.Therefore, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.
基金This work was supported by the Key Program of the National Natural Science Foundation of China(No.51738005)the Youth Program of National Natural Science Foundation of China(No.51908317).
文摘As water reuse development has increased,biological stability issues associated with reclaimed water have gained attention.This study evaluated assimilable organic carbon(AOC)in effluents from a full-scale membrane biological reactor(MBR)plant and found that they were generally stable over one year(125-216µg/L),with slight increases in warmer seasons.After additional tertiary treatments,the largest increases in absolute and specific AOCs were detected during ozonation,followed by coagulation-ozonation and coagulation.Moreover,UV254 absorbance is known to be an effective surrogate to predict the AOC changes during ozonation.Applying coagulation prior to ozonation of MBR effluents for removal of large molecules was found to reduce the AOC formation compared with ozonation treatment alone.Finally,the results revealed that attention should be paid to seasonal variations in influent and organic fraction changes during treatment to enable sustainable water reuse.
基金supported by the Key Program of the National Natural Science Foundation of China(Grant No.51738005).
文摘The risks posed by algal blooms caused by nitrogen and phosphorus in reclaimed water used in urban water landscapes need to be carefully controlled.In this study,the combined effects of the nitrogen and phosphorus concentrations and the light intensity and temperature on the specific growth rates of algae were determined using Monod,Steele,and Arrhenius models,then an integrated algal growth model was developed.The algae biomass,nitrogen concentration,and phosphorus concentration mass balance equations were used to establish a new control model describing the nitrogen and phosphorus concentration and hydraulic retention time thresholds for algal blooms.The model parameters were determined by fitting the models to data acquired experimentally.Finally,the control model and numerical simulations for six typical algae and mixed algae under standard conditions were used to determine nitrogen/phosphorus concentration and hydraulic retention time thresholds for landscape water to which reclaimed water is supplied(i.e.,for a reclaimed water landscape).
基金funded by the National Science Fund of China (Nos. 51138006, 51290284)the National High-Tech R&D Program (863) of China (No. 2013AA065205)+1 种基金the Key Science and Technology Project of Shenzhen Water AuthorityThe Collaborative Innovation Center for Regional Environmental Quality also supported this research
文摘Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter（DOM） was investigated in this study. Solar light significantly decreased the UV_（254） absorbance and fluorescence（FLU） intensity of reclaimed water.However, its effect on the dissolved organic carbon（DOC） value of reclaimed water was very limited. The decrease in the UV_（254） absorbance intensity and FLU excitation–emission matrix regional integration volume（FLU volume） of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV_（254） absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV_（254） absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV_（254） and FLU intensity were independent of light intensity. The peaks of the UV_（254） absorbance and FLU intensity with an apparent molecular weight（AMW） of 100 Da to 2000 Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change.
基金This study was supported by a grant from the Science Foundation for SARS of Guangdong Province(No.2003Z3-E0461)
文摘Background Although severe acute respiratory syndrome （SARS） has been controlled, the subsequently emerging sporadic cases in 2004 emphasize the necessity of developing a rapid diagnostic method, which would be of great help in clinical diagosis and also wild host screening. This study aims to establish an effective and rapid serological tool for the diagnosis of SARS-CoV by comparison among whole viral, N and N199 proteins by ELISA. Methods SARS-CoV N and N199 （a truncated nucleocapsid gene） genes were cloned, expressed, identified by Western blotting, and applied in screening of human and swine samples. Sera of SARS convalescent-phase patients, normal human sera, sera of patients with other respiratory diseases, and swine sera were screened by ELISA, with whole SARS-CoV F69, N and N199 proteins as antigens. Results The sensitivity and specificity of N and N199 proteins in human sera diagnosis were approximate （P=-0.743）, which was higher than whole viral protein but the difference was not significant （P=-0.234）. The N199 protein proved to be more specific in swine sera screening than whole viral and N protein （P〈0.001）. Conclusion N199 protein is feasible in both clinical diagnosis and SARS-CoV reservoir screening.
基金supported by the National Key Research and Development Program of China (2020YFC0841400-008)the National Science and Technology Major Projects(2018ZX09711003-013-002)the National Natural Science Foundation of China (81673339 and 81773619)
文摘In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.
基金financially supported by the National Key Research and Development Program of China(No.2019YFA0905601)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB38020300)China Microbiome Initiative(CMI)supported by Chinese Academy of Sciences(CAS-CMI).
文摘Impact statement Nonhuman primates(NHPs)such as monkeys are the closest living relatives to humans and are the best available models for causative studies of human health and diseases.Gut microbiomes are intensively involved in host health.In this study,by large-scale cultivation of microbes from fecal samples of monkeys,we obtained previously uncultured bacterial species and constructed a Macaca fascicularis Gut Microbial Biobank(MfGMB).The MfGMB consisted of 250 strains that represent 97 species of 63 genera,25 families,and 4 phyla.The information of the 250 strains and the genomes of 97 cultured species are publicly accessible.The MfGMB represented nearly 50% of core gut microbial compositions at the genus level and covered over 80% of the KO-based known gut microbiome functions of M.fascicularis.Data mining showed that the bacterial species in the MfGMB were prevalent not only in NHPs gut microbiomes but also in human gut microbiomes.This study will help the understanding and future investigations on how gut microbiomes interact with their mammalian hosts.
基金Supported by the National Natural Science Foundation of China(No.30970550)
文摘The aim of this study was to investigate the distribution, density, community structure and biodiversity characteristics of benthic diatoms, and to analyze whether differences in species composition and abundance exist in different regions of the Niyang River, Tibet. Among the 157 taxa observed in 15 sampling sites in the main river and tributary, most were casual species （〉100）, the relative abundance of the genera Achnantkes and Fragilaria was 67% of the total relative abundance. Acknantkes minutissima was the most important species and dominated the whole river reaches （average relative abundance was 30%）; the average diatom densities were 7.4 x 105 cell/cm2 at all sites, and increased slowly from the upper section to downriver. The significant indicator taxa with higher relative abundance were Achnanthes biasolettiana （18.0%） and Fragilaria arcus （18.2%）, Fragilaria capucina var. vaucheriae （31.2%）, Fragilaria construens var. renter （11.3%） and Cymbella affinis （11.0%） in the upper, tributary and mid-river sections, respectively. Achnanthes minutissima was the most abundant species （56%） in the downriver section. Biodiversity indices showed a gradual decrease from the up- to down-river section, and dominant species were more abundant in the upper and mid-river sections than in the downriver section. A two-way indictor species analysis （TWINSPAN） of diatom composition clearly showed four different groups, namely the upper, mid, lower and tributary sections. Detrended correspondence analysis （DCA） supported the results of TW1NSPAN, and the characteristics of site distribution and species composition in the Niyang River supported the spatial structure of diatom assemblages. This study indicates that bio-assessment programs utilizing benthic diatoms could clearly benefit lotic water with regional stratification.
基金financed by CAPES (Coordenao de Aperfeioamento de Pessoal de Nível Superior)
文摘A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand＆ plantations in the semiarid region （ 15° 09′ S 43° 49′ W） in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass （dry matter） was 33.6 Mg.ha^-1 for E. camaldulensis and 53.1 Mg·ha^-1 for E. grandis. The biomass of the stem wood, leaves, branches, and stein bark for E. camaldulens accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively （Table 2）; meanwhile a similar partition of the total above-ground biomass was also found for E. grand＆. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk （bark and wood）, nutrient accumulation in general was lower. Nutrient content of E. grand＆ presented little variation compared with that orE. camaJd^llensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grand＆. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy.
