To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and ...To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.展开更多
The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and cul...The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.展开更多
Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have...Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have become a hot research topic in growth improvement in aquaculture.The endogenous probiotic bacteria from intestines of Macrobrachium rosenbergii(giant river prawn)was explored for their probiotic potential,from which 367 bacterial strains were isolated from the intestine of M.rosenbergii.After 16 S rDNA sequence analysis,234 isolates were identified as Lactococcus garvieae,which accounted for 63.76%of the total number of culturable intestinal bacteria,suggesting that this bacterium was the main component of the microbiota.Furthermore,to reveal the probiotic properties of L.garvieae,this isolated bacterial strain was characterized morphologically,physiologically,and biochemically.Its enzyme production capacity,bacteriostatic activity,and resistance to acid,high temperature,and pH,were assessed.In vitro experiments showed that the L.garvieae(No.C 6 a 2)had a fast growth rate and entered the logarithmic phase rapidly.Besides,it had characteristics of acid-production and resistance,enzyme-producing capacity,and strong antibacterial activity against pathogenic Staphylococc us aureus,Aeromonas hydrophila,and Aeromonas veronii.However,it lacked the ability to tolerate high temperature.Our results provide novel data to deepen our understanding of the intestinal bacteria structure of M.rosenbergii and valuable information for probiotic screening and the application for M.rosenbergii.展开更多
Using alternative plant-derived dietary protein to replace fishmeal,combined with practical evaluation indexes,is a recent focus for aquaculture practices.An 8-week feeding experiment with giant freshwater prawn Macro...Using alternative plant-derived dietary protein to replace fishmeal,combined with practical evaluation indexes,is a recent focus for aquaculture practices.An 8-week feeding experiment with giant freshwater prawn Macrobrachium rosenbergii post-larvae was conducted to determine the eff ects of replacing fi shmeal(FM)with soybean meal in the feed,in terms of growth performance,antioxidant capacity,intestinal microbiota,and mRNA expression of target of rapamycin(TOR)and ribosomal protein S6 kinase B1(S6K1).Four isonitrogenous diets with isocaloric value were prepared to contain 100%,75%,50%,or 25%FM as the protein source(dietary treatments FM100,FM75,FM50,and FM25,respectively).Each diet was fed to post-larval prawns(mean weight 0.045±0.002 g)twice a day in four replicates.No signifi cant diff erence in weight gain was observed among all groups,but the survival rate of prawns fed the FM50 and FM25 diets was signifi cantly lower than that of prawns fed the FM diet.The mRNA expression of both TOR and S6K1 were the lowest in hepatopancreas of prawns fed the FM25 diet.Superoxide dismutase activity of prawns fed the FM25 diet was significantly lower than that of prawns fed FM50.In contrast,the malondialdehyde content was signifi cantly higher in prawns fed FM25 as compared with those fed FM75.The proportion of fishmeal in the diet did not affect the composition of core(phylum-level)intestinal microbiota,but greater fishmeal replacement with soybean meal had a potential risk to increase the relative abundance of opportunistic pathogens in the gut when considered at the genus level.These results suggest that fishmeal replacement with soybean meal should not exceed 50%in a diet for post-larval M.rosenbergii.展开更多
Purpose:This paper studies the relationship between the impact factor(IF)and the number of journal papers in Chinese publishing system.Design/methodology/approach:The method proposed by Huang(2016)is used whereas to a...Purpose:This paper studies the relationship between the impact factor(IF)and the number of journal papers in Chinese publishing system.Design/methodology/approach:The method proposed by Huang(2016)is used whereas to analysis the data of Chinese journals in this study.Findings:Based on the analysis,we find the following.(1)The average impact factor(AIF)of journals in all disciplines maintained a growth trend from 2007 to 2017.Whether before or after removing outlier journals that may garner publication fees,the IF and its growth rate for most social sciences disciplines are larger than those of most natural sciences disciplines,and the number of journal papers on social sciences disciplines decreased while that of natural sciences disciplines increased from 2007 to 2017.(2)The removal of outlier journals has a greater impact on the relationship between the IF and the number of journal papers in some disciplines such as Geosciences because there may be journals that publish many papers to garner publication fees.(3)The success-breeds-success(SBS)principle is applicable in Chinese journals on natural sciences disciplines but not in Chinese journals on social sciences disciplines,and the relationship is the reverse of the SBS principle in Economics and Education&Educational Research.(4)Based on interviews and surveys,the difference in the relationship between the IF and the number of journal papers for Chinese natural sciences disciplines and Chinese social sciences disciplines may be due to the influence of the international publishing system.Chinese natural sciences journals are losing their academic power while Chinese social sciences journals that are less influenced by the international publishing system are in fierce competition.Research limitation:More implications could be found if long-term tracking and comparing the international publishing system with Chinese publishing system are taken.Practical implications:It is suggested that researchers from different countries study natural science and social sciences journals in their languages and observe the influence of the international publishing system.Originality/value:This paper presents an overview of the relationship between IF and the number of journal papers in Chinese publishing system from 2007 to 2017,provides insights into the relationship in different disciplines in Chinese publishing system,and points out the similarities and differences between Chinese publishing system and international publishing system.展开更多
Purpose: This paper aims to investigate the scientific productivity of China's science system. Design/methodology/approach: This paper employs the Malmquist productivity index(MPI) based on Data Envelopment Analys...Purpose: This paper aims to investigate the scientific productivity of China's science system. Design/methodology/approach: This paper employs the Malmquist productivity index(MPI) based on Data Envelopment Analysis(DEA).Findings: The results reveal that the overall efficiency of Chinese universities increased significantly from 2009 to 2016, which is mainly driven by technological progress. From the perspective of the functions of higher education, research and transfer activities perform better than the teaching activities.Research limitations: As an implication, the indicator selection mechanism, investigation period and the MPI model can be further extended in the future research.Practical implications: The results indicate that Chinese education administrative departments should take actions to guide and promote the teaching activities and formulate reasonable resource allocation regulations to reach the balanced development in Chinese universities.Originality/value: This paper selects 58 Chinese universities and conducts a quantified measurement during the period 2009–2016. Three main functional activities of universities(i.e. teaching, researching, and application) are innovatively categorized into different schemes, and we calculate their performance, respectively.展开更多
Objective: An epidemiological investigation was carried out in school X in Jinan, Shandong Province, China, to identify the cause, epidemiology, and etiological characteristics of a febrile respiratory disease outbrea...Objective: An epidemiological investigation was carried out in school X in Jinan, Shandong Province, China, to identify the cause, epidemiology, and etiological characteristics of a febrile respiratory disease outbreak;and therefore to control the dissemination. Methods: Both field epidemiological investigations and laboratory examinations were carried out. Results: Forty cases were identified, in which 38 cases were students and two were teachers. Clinical manifestations included fever, coughing, headache, and sore throat. A total of 21 pharyngeal swab specimens were collected and 18?tested positive for adenovirus. The adenovirus hexon gene was sequenced in three of the 18 positive specimens and the results?showed a 100% homology with the standard HAdV-55 HEXO. Conclusions: The outbreak originated from an adenovirus-infected student, who spread the pathogen to her classmates and teacher. The teacher then further disseminated the disease within the school which led to 40 febrile respiratory infections.展开更多
In the context of the rapid development of the digital economy,regional innovation efficiency(RIE)has become an important indicator for measuring regional economic competitiveness.This study establishes an evaluation ...In the context of the rapid development of the digital economy,regional innovation efficiency(RIE)has become an important indicator for measuring regional economic competitiveness.This study establishes an evaluation system for RIE driven by the digital economy,employing a two-stage inverse data envelopment analysis(DEA)model to measure RIE in China.It also conducts an empirical analysis of the allocation of technological resources in Jiangsu Province,providing valuable insights for RIE research within the framework of the digital economy.The research results indicate that from 2014 to 2019,the overall RIE in China gradually improved,with significant increases in innovation efficiency in the eastern and western regions,while the northeastern region experienced a slight decline.Focusing on resource allocation in Jiangsu,we find that as the input proportion gradually increases,it is necessary to reduce output in the technology development stage and enhance output in the achievement transformation stage to maintain the current efficiency level.However,to improve the RIE score,it is essential to simultaneously increase the output levels of both stages.展开更多
Bacterial infection, especially multidrug-resistant(MDR) bacterial infection has threatened public health drastically. Here, we fabricate an "acid-triggered" nanoplatform for enhanced photodynamic antibacter...Bacterial infection, especially multidrug-resistant(MDR) bacterial infection has threatened public health drastically. Here, we fabricate an "acid-triggered" nanoplatform for enhanced photodynamic antibacterial activity by reducing the aggregation of photosensitizers(PSs) in bacterial acidic microenvironment. Specifically, a functional amphiphilic block copolymer was first synthesized by using a pH-sensitive monomer, 2-(diisopropylamino) ethyl methacrylate(DPA) and porphyrin-based methacrylate(TPPC6MA) with poly(oligo(ethylene glycol) methyl ether methacrylate)(POEGMA) as the macromolecular chain transfer agent, and POEGMA-b-[PDPA-co-PTPPC6MA] block copolymer was further self-assembled into spherical nanoparticles(PDPA-TPP). PDPA-TPP nanoparticles possess an effective electrostatic adherence to negatively charged bacterial cell membrane, since they could rapidly achieve positive charge in acidic bacterial media. Meanwhile, the acid-triggered dissociation of PDPA-TPP nanoparticles could reduce the aggregation caused quenching(ACQ) of the photosensitizers, leading to around 5 folds increase of the singlet oxygen(1O2) quantum yield. In vitro results demonstrated that the "acid-triggered" PDPA-TPP nanoparticles could kill most of MDR S. aureus(Gram-positive) and MDR E. coli(Gram-negative) by enhanced photodynamic therapy, and they could resist wound infection and accelerate wound healing effectively in vivo. Furthermore, PDPA-TPP nanoparticles could well disperse the biofilm and almost kill all the biofilm-containing bacteria. Thus, by making use of the bacterial acidic microenvironment, this "acid-triggered" nanoplatform in situ will open a new path to solve the aggregation of photosensitizers for combating broad-spectrum drug-resistant bacterial infection.展开更多
Recently,two-dimensional(2D)transition metal carbides and carbonitrides(MXenes),have shown great potential in micro-supercapacitors(MSCs).However,the maximum voltage output of symmetric MXene MSCs is limited to 0.6 V ...Recently,two-dimensional(2D)transition metal carbides and carbonitrides(MXenes),have shown great potential in micro-supercapacitors(MSCs).However,the maximum voltage output of symmetric MXene MSCs is limited to 0.6 V due to the oxidation effects at high anodic potentials.Herein,we developed asymmetric micro-supercapacitors(AMSCs)based on titanium carbide MXene(Ti_(3)C_(2)Tx)and MXene-MoO_(2) electrodes with an enlarged voltage window of 1.2 V,which is twice wider than that of symmetric MXene MSCs.The 2D-0D MXene-MoO_(2) microelectrode is fabricated by homogenous dispersing zerodimensional(0D)MoO_(2) nanoparticles into MXene layers to impede layers stacking and MoO_(2) nanoparticles aggregation.Notably,the AMSCs delivered good electrochemical performances of areal capacitance of ~19 mF cm^(-2) and volumetric capacitance of 63 F cm^(-3) at a scan rate of 2 mV s^(-1),and high energy density of 9.7 mW h cm^(-3) at a power density of 0.198 W cm^(-3).The AMSCs also presented exceptionally mechanical flexibility under different bending states and excellent cyclic stability,with 88% capacitance retention after 10000 cycles at a discharge current density of 0.5 mA cm^(-2).For practical application,the serially connected AMSCs are fully affordable to power electronics,which is beneficial for soft and wearable power devices.展开更多
This paper proposed a multi-period dynamic optimal portfolio selection model. Assumptions were made to assure the strictness of reasoning. This Approach depicted the developments and changing of the real stock market ...This paper proposed a multi-period dynamic optimal portfolio selection model. Assumptions were made to assure the strictness of reasoning. This Approach depicted the developments and changing of the real stock market and is an attempt to remedy some of the deficiencies of recent researches. The model is a standard form of quadratic programming. Furthermore, this paper presented a numerical example in real stock market.展开更多
Discrete Pt(Ⅱ)metallacycles have attracted particular attention for the chemotherapeutic treatment of cancer.However,a single chemotherapy cannot simultaneously balance efficiency and safety because the continuous ad...Discrete Pt(Ⅱ)metallacycles have attracted particular attention for the chemotherapeutic treatment of cancer.However,a single chemotherapy cannot simultaneously balance efficiency and safety because the continuous administration throughout the entire therapy period will lead to inefficient therapy and potentially long-term systemic toxicity.Therefore,the development of a novel organoplatinum(Ⅱ)metallacycle with multimodal treatment capabilities is urgently needed to overcome these issues.Herein,a discrete Pt(II)metallacycle(SCY)bearing the near-infrared(NIR)photosensitizer heptamethine cyanine was fabricated and further encapsulated by amphiphilic 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy(polyethyleneglycol)(DSPEmPEG)to form P@SCY nanoparticles.Heptamethine cyanine,which has excellent photoconversion efficiency,can generate reactive oxygen species(ROS)and heat simultaneously,and the cyanine moiety can target mitochondria in cancer cells due to their quaternary ammonium salt cations,which improve the effect of phototherapy.Due to its excellent phototherapy and chemotherapy properties,P@SCY exhibited remarkable trimodal therapeutic effects[chemo-/photodynamic therapy(PDT)/photothermal therapy(PTT)]against cancer cells(HepG2 cells,MCF-7 cells,and 4T1 cells)in vitro.Furthermore,in vivo results also confirmed thatP@SCY had superior antitumor properties with minimal side effects in the 4T1 tumor model.Thiswork presents a practicable approach to develop a multifunctional organoplatinum(Ⅱ)metallacycle for multimodal tumor therapy.展开更多
Congestion is an economic phenomenon of overinvestment that occurs when excessive inputs decrease the maximally possible outputs.Although decision-makers are unlikely to decrease outputs by increasing inputs,congestio...Congestion is an economic phenomenon of overinvestment that occurs when excessive inputs decrease the maximally possible outputs.Although decision-makers are unlikely to decrease outputs by increasing inputs,congestion is widespread in reality.Identifying and measuring congestion can help decision-makers detect the problem of overinvestment.This paper reviews the development of the concept of congestion in the framework of data envelopment analysis(DEA),which is a widely accepted method for identifying and measuring congestion.In this paper,six main congestion identification and measurement methods are analysed through several numerical examples.We investigate the ideas of these methods,the contributions compared with the previous methods,and the existing shortcomings.Based on our analysis,we conclude that existing congestion identification and measurement methods are still inadequate.Three problems are anticipated for further study:maintaining the consistency between congestion and overinvestment,considering joint weak disposability assumption between desirable outputs and undesirable outputs,and quantifying the degree of congestion.展开更多
This paper aims to measure the productivity of academic journals in the field of management science and operations research on the basis of a data envelopment analysis(DEA)-Malmquist approach.Using the empirical resul...This paper aims to measure the productivity of academic journals in the field of management science and operations research on the basis of a data envelopment analysis(DEA)-Malmquist approach.Using the empirical results,we make the following findings:(1)Compared with the DEA-CCR(Charnes,Cooper,Rhodes)model,the DEA-BCC(Banker,Charnes,Cooper)model may overestimate the performance of journals with a shorter cited half-life and fewer articles,and may underestimate the performance of journals with a longer cited half-life and more articles;(2)The average performance of journals in the management science and operations research field progressed by 1.8%during 2007-2014,which was a result of the frontier-shift effect;(3)The gap between the best journals on the DEA frontier and the rest of the journals is increasing because the best journals grow relatively faster;(4)High-level journals have made more progress and their performance is more stable,and the difference between high-level journals was also smaller during 2007-2014;and,(5)A higher total factor productivity value corresponds to higher Association of Business Schools rankings for certain journals.展开更多
Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and...Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and superoxide radical(O^(-)_(2)) photogenerator(TB) against hypoxic tumors. TB particularly possessed a favorable O^(-)_(2) generation capability under 808 nm laser irradiation with the donoracceptor-donor(D-A-D) molecular structure. Moreover, owing to molecular rotation, potent hyperthermia was realized under continuous laser irradiation. For the usage of hypoxic tumor treatment, TB was encapsulated by a block copolymer,poly(ethylene glycol)-b-poly(latic acid)(PEG_(45)-b-PLA_(24)), to fabricate phototheranostic nanoparticles(TB NPs). Due to the twisted molecular structure and the shielding effect of long alkyl chains, the π-π stacking-induced quenching of O^(-)_(2) could be reduced after the fabrication of nano-assemblies. Significantly, TB NPs exhibited satisfactory O^(-)_(2) generation for type I PDT and a simultaneously distinct photothermal conversion efficiency(PCE, 62%) for photothermal therapy(PTT)to combat hypoxic tumor cells. Moreover, the high PCE endowed TB NPs with high-performance photoacoustic(PA)and photothermal imaging capability. In vivo experiments demonstrated that TB NPs possessed an outstanding phototherapeutic efficacy for eradicating hypoxic tumors. This study established a novel approach for constructing oxygenindependent phototherapeutic reagent against hypoxic tumors.展开更多
This studyfirst proposes a definition for directional congestion in certain input and output directions within the framework of data envelopment analysis.Second,two methods from different viewpoints are proposed to es...This studyfirst proposes a definition for directional congestion in certain input and output directions within the framework of data envelopment analysis.Second,two methods from different viewpoints are proposed to estimate the directional congestion.Third,we address the relationship between directional congestion and classic(strong or weak)congestion.Finally,we present a case study investigating the analysis performed by the research institutes of the Chinese Academy of Sciences to demonstrate the applicability and usefulness of the methods developed in this study.展开更多
基金Supported by the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(No.2021 C 02069-4-3)the Major Research&Development Program(modern agriculture)of Jiangsu Province(No.BE 2019352)。
文摘To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.
基金Supported by the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural(Aquaculture)Varieties(No.2021C02069-4-3)the Major Research&Development Program(Modern Agriculture)of Jiangsu Province(No.BE2019352)+1 种基金the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Innovation Project of Postgraduate Scientific Research in Huzhou University in 2022(No.2022KYCX63)。
文摘The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.
基金Supported by the National Natural Science Foundation of China(No.32273121)the Natural Science Foundation of Zhejiang Province(No.LGN22C190019)+1 种基金the Huzhou Natural Science Foundation(No.2021YZ08)the earmarked fund for the China Agriculture Research System of MOF and MARA(No.CARS-48)。
文摘Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have become a hot research topic in growth improvement in aquaculture.The endogenous probiotic bacteria from intestines of Macrobrachium rosenbergii(giant river prawn)was explored for their probiotic potential,from which 367 bacterial strains were isolated from the intestine of M.rosenbergii.After 16 S rDNA sequence analysis,234 isolates were identified as Lactococcus garvieae,which accounted for 63.76%of the total number of culturable intestinal bacteria,suggesting that this bacterium was the main component of the microbiota.Furthermore,to reveal the probiotic properties of L.garvieae,this isolated bacterial strain was characterized morphologically,physiologically,and biochemically.Its enzyme production capacity,bacteriostatic activity,and resistance to acid,high temperature,and pH,were assessed.In vitro experiments showed that the L.garvieae(No.C 6 a 2)had a fast growth rate and entered the logarithmic phase rapidly.Besides,it had characteristics of acid-production and resistance,enzyme-producing capacity,and strong antibacterial activity against pathogenic Staphylococc us aureus,Aeromonas hydrophila,and Aeromonas veronii.However,it lacked the ability to tolerate high temperature.Our results provide novel data to deepen our understanding of the intestinal bacteria structure of M.rosenbergii and valuable information for probiotic screening and the application for M.rosenbergii.
基金Supported by the Agriculture Ministry Key Laboratory of Healthy Freshwater Aquaculture and the Key Laboratory of Freshwater Aquaculture Genetic and Breeding of Zhejiang Province of the Zhejiang Institute of Freshwater Fisheries(No.ZJK201906)。
文摘Using alternative plant-derived dietary protein to replace fishmeal,combined with practical evaluation indexes,is a recent focus for aquaculture practices.An 8-week feeding experiment with giant freshwater prawn Macrobrachium rosenbergii post-larvae was conducted to determine the eff ects of replacing fi shmeal(FM)with soybean meal in the feed,in terms of growth performance,antioxidant capacity,intestinal microbiota,and mRNA expression of target of rapamycin(TOR)and ribosomal protein S6 kinase B1(S6K1).Four isonitrogenous diets with isocaloric value were prepared to contain 100%,75%,50%,or 25%FM as the protein source(dietary treatments FM100,FM75,FM50,and FM25,respectively).Each diet was fed to post-larval prawns(mean weight 0.045±0.002 g)twice a day in four replicates.No signifi cant diff erence in weight gain was observed among all groups,but the survival rate of prawns fed the FM50 and FM25 diets was signifi cantly lower than that of prawns fed the FM diet.The mRNA expression of both TOR and S6K1 were the lowest in hepatopancreas of prawns fed the FM25 diet.Superoxide dismutase activity of prawns fed the FM25 diet was significantly lower than that of prawns fed FM50.In contrast,the malondialdehyde content was signifi cantly higher in prawns fed FM25 as compared with those fed FM75.The proportion of fishmeal in the diet did not affect the composition of core(phylum-level)intestinal microbiota,but greater fishmeal replacement with soybean meal had a potential risk to increase the relative abundance of opportunistic pathogens in the gut when considered at the genus level.These results suggest that fishmeal replacement with soybean meal should not exceed 50%in a diet for post-larval M.rosenbergii.
基金This work was financially supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2018JJ3298)the Ph.D.Scientific research Start-up Project of Xinjiang University(Grant No.BS202104)the Tianchi Doctoral Project of Xinjiang(Grant No.TCBS202050).
文摘Purpose:This paper studies the relationship between the impact factor(IF)and the number of journal papers in Chinese publishing system.Design/methodology/approach:The method proposed by Huang(2016)is used whereas to analysis the data of Chinese journals in this study.Findings:Based on the analysis,we find the following.(1)The average impact factor(AIF)of journals in all disciplines maintained a growth trend from 2007 to 2017.Whether before or after removing outlier journals that may garner publication fees,the IF and its growth rate for most social sciences disciplines are larger than those of most natural sciences disciplines,and the number of journal papers on social sciences disciplines decreased while that of natural sciences disciplines increased from 2007 to 2017.(2)The removal of outlier journals has a greater impact on the relationship between the IF and the number of journal papers in some disciplines such as Geosciences because there may be journals that publish many papers to garner publication fees.(3)The success-breeds-success(SBS)principle is applicable in Chinese journals on natural sciences disciplines but not in Chinese journals on social sciences disciplines,and the relationship is the reverse of the SBS principle in Economics and Education&Educational Research.(4)Based on interviews and surveys,the difference in the relationship between the IF and the number of journal papers for Chinese natural sciences disciplines and Chinese social sciences disciplines may be due to the influence of the international publishing system.Chinese natural sciences journals are losing their academic power while Chinese social sciences journals that are less influenced by the international publishing system are in fierce competition.Research limitation:More implications could be found if long-term tracking and comparing the international publishing system with Chinese publishing system are taken.Practical implications:It is suggested that researchers from different countries study natural science and social sciences journals in their languages and observe the influence of the international publishing system.Originality/value:This paper presents an overview of the relationship between IF and the number of journal papers in Chinese publishing system from 2007 to 2017,provides insights into the relationship in different disciplines in Chinese publishing system,and points out the similarities and differences between Chinese publishing system and international publishing system.
基金the financial support from National Natural Science Foundation (NSFC, No. 71671181)
文摘Purpose: This paper aims to investigate the scientific productivity of China's science system. Design/methodology/approach: This paper employs the Malmquist productivity index(MPI) based on Data Envelopment Analysis(DEA).Findings: The results reveal that the overall efficiency of Chinese universities increased significantly from 2009 to 2016, which is mainly driven by technological progress. From the perspective of the functions of higher education, research and transfer activities perform better than the teaching activities.Research limitations: As an implication, the indicator selection mechanism, investigation period and the MPI model can be further extended in the future research.Practical implications: The results indicate that Chinese education administrative departments should take actions to guide and promote the teaching activities and formulate reasonable resource allocation regulations to reach the balanced development in Chinese universities.Originality/value: This paper selects 58 Chinese universities and conducts a quantified measurement during the period 2009–2016. Three main functional activities of universities(i.e. teaching, researching, and application) are innovatively categorized into different schemes, and we calculate their performance, respectively.
文摘Objective: An epidemiological investigation was carried out in school X in Jinan, Shandong Province, China, to identify the cause, epidemiology, and etiological characteristics of a febrile respiratory disease outbreak;and therefore to control the dissemination. Methods: Both field epidemiological investigations and laboratory examinations were carried out. Results: Forty cases were identified, in which 38 cases were students and two were teachers. Clinical manifestations included fever, coughing, headache, and sore throat. A total of 21 pharyngeal swab specimens were collected and 18?tested positive for adenovirus. The adenovirus hexon gene was sequenced in three of the 18 positive specimens and the results?showed a 100% homology with the standard HAdV-55 HEXO. Conclusions: The outbreak originated from an adenovirus-infected student, who spread the pathogen to her classmates and teacher. The teacher then further disseminated the disease within the school which led to 40 febrile respiratory infections.
基金supported by the National Natural Science Foundation of China(72071196)
文摘In the context of the rapid development of the digital economy,regional innovation efficiency(RIE)has become an important indicator for measuring regional economic competitiveness.This study establishes an evaluation system for RIE driven by the digital economy,employing a two-stage inverse data envelopment analysis(DEA)model to measure RIE in China.It also conducts an empirical analysis of the allocation of technological resources in Jiangsu Province,providing valuable insights for RIE research within the framework of the digital economy.The research results indicate that from 2014 to 2019,the overall RIE in China gradually improved,with significant increases in innovation efficiency in the eastern and western regions,while the northeastern region experienced a slight decline.Focusing on resource allocation in Jiangsu,we find that as the input proportion gradually increases,it is necessary to reduce output in the technology development stage and enhance output in the achievement transformation stage to maintain the current efficiency level.However,to improve the RIE score,it is essential to simultaneously increase the output levels of both stages.
基金supported by the National Natural Science Foundation of China(21875063)the Science and Technology Commission of Shanghai Municipality for the Shanghai International Cooperation Program(19440710600)。
文摘Bacterial infection, especially multidrug-resistant(MDR) bacterial infection has threatened public health drastically. Here, we fabricate an "acid-triggered" nanoplatform for enhanced photodynamic antibacterial activity by reducing the aggregation of photosensitizers(PSs) in bacterial acidic microenvironment. Specifically, a functional amphiphilic block copolymer was first synthesized by using a pH-sensitive monomer, 2-(diisopropylamino) ethyl methacrylate(DPA) and porphyrin-based methacrylate(TPPC6MA) with poly(oligo(ethylene glycol) methyl ether methacrylate)(POEGMA) as the macromolecular chain transfer agent, and POEGMA-b-[PDPA-co-PTPPC6MA] block copolymer was further self-assembled into spherical nanoparticles(PDPA-TPP). PDPA-TPP nanoparticles possess an effective electrostatic adherence to negatively charged bacterial cell membrane, since they could rapidly achieve positive charge in acidic bacterial media. Meanwhile, the acid-triggered dissociation of PDPA-TPP nanoparticles could reduce the aggregation caused quenching(ACQ) of the photosensitizers, leading to around 5 folds increase of the singlet oxygen(1O2) quantum yield. In vitro results demonstrated that the "acid-triggered" PDPA-TPP nanoparticles could kill most of MDR S. aureus(Gram-positive) and MDR E. coli(Gram-negative) by enhanced photodynamic therapy, and they could resist wound infection and accelerate wound healing effectively in vivo. Furthermore, PDPA-TPP nanoparticles could well disperse the biofilm and almost kill all the biofilm-containing bacteria. Thus, by making use of the bacterial acidic microenvironment, this "acid-triggered" nanoplatform in situ will open a new path to solve the aggregation of photosensitizers for combating broad-spectrum drug-resistant bacterial infection.
基金financially supported by the Australian Research Council Discovery Program(DP190103290)Australian Research Council Discovery Early Career Researcher Award scheme(DE150101617).
文摘Recently,two-dimensional(2D)transition metal carbides and carbonitrides(MXenes),have shown great potential in micro-supercapacitors(MSCs).However,the maximum voltage output of symmetric MXene MSCs is limited to 0.6 V due to the oxidation effects at high anodic potentials.Herein,we developed asymmetric micro-supercapacitors(AMSCs)based on titanium carbide MXene(Ti_(3)C_(2)Tx)and MXene-MoO_(2) electrodes with an enlarged voltage window of 1.2 V,which is twice wider than that of symmetric MXene MSCs.The 2D-0D MXene-MoO_(2) microelectrode is fabricated by homogenous dispersing zerodimensional(0D)MoO_(2) nanoparticles into MXene layers to impede layers stacking and MoO_(2) nanoparticles aggregation.Notably,the AMSCs delivered good electrochemical performances of areal capacitance of ~19 mF cm^(-2) and volumetric capacitance of 63 F cm^(-3) at a scan rate of 2 mV s^(-1),and high energy density of 9.7 mW h cm^(-3) at a power density of 0.198 W cm^(-3).The AMSCs also presented exceptionally mechanical flexibility under different bending states and excellent cyclic stability,with 88% capacitance retention after 10000 cycles at a discharge current density of 0.5 mA cm^(-2).For practical application,the serially connected AMSCs are fully affordable to power electronics,which is beneficial for soft and wearable power devices.
文摘This paper proposed a multi-period dynamic optimal portfolio selection model. Assumptions were made to assure the strictness of reasoning. This Approach depicted the developments and changing of the real stock market and is an attempt to remedy some of the deficiencies of recent researches. The model is a standard form of quadratic programming. Furthermore, this paper presented a numerical example in real stock market.
基金the National Natural Science Foundation of China(nos.21875063,21922506,and 21871092)the Science and Technology Commission of Shanghai Municipality for the Shanghai International Cooperation Program(no.19440710600).
文摘Discrete Pt(Ⅱ)metallacycles have attracted particular attention for the chemotherapeutic treatment of cancer.However,a single chemotherapy cannot simultaneously balance efficiency and safety because the continuous administration throughout the entire therapy period will lead to inefficient therapy and potentially long-term systemic toxicity.Therefore,the development of a novel organoplatinum(Ⅱ)metallacycle with multimodal treatment capabilities is urgently needed to overcome these issues.Herein,a discrete Pt(II)metallacycle(SCY)bearing the near-infrared(NIR)photosensitizer heptamethine cyanine was fabricated and further encapsulated by amphiphilic 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy(polyethyleneglycol)(DSPEmPEG)to form P@SCY nanoparticles.Heptamethine cyanine,which has excellent photoconversion efficiency,can generate reactive oxygen species(ROS)and heat simultaneously,and the cyanine moiety can target mitochondria in cancer cells due to their quaternary ammonium salt cations,which improve the effect of phototherapy.Due to its excellent phototherapy and chemotherapy properties,P@SCY exhibited remarkable trimodal therapeutic effects[chemo-/photodynamic therapy(PDT)/photothermal therapy(PTT)]against cancer cells(HepG2 cells,MCF-7 cells,and 4T1 cells)in vitro.Furthermore,in vivo results also confirmed thatP@SCY had superior antitumor properties with minimal side effects in the 4T1 tumor model.Thiswork presents a practicable approach to develop a multifunctional organoplatinum(Ⅱ)metallacycle for multimodal tumor therapy.
基金the support from National Natural Science Foundation of China(No.71671181,72071196).
文摘Congestion is an economic phenomenon of overinvestment that occurs when excessive inputs decrease the maximally possible outputs.Although decision-makers are unlikely to decrease outputs by increasing inputs,congestion is widespread in reality.Identifying and measuring congestion can help decision-makers detect the problem of overinvestment.This paper reviews the development of the concept of congestion in the framework of data envelopment analysis(DEA),which is a widely accepted method for identifying and measuring congestion.In this paper,six main congestion identification and measurement methods are analysed through several numerical examples.We investigate the ideas of these methods,the contributions compared with the previous methods,and the existing shortcomings.Based on our analysis,we conclude that existing congestion identification and measurement methods are still inadequate.Three problems are anticipated for further study:maintaining the consistency between congestion and overinvestment,considering joint weak disposability assumption between desirable outputs and undesirable outputs,and quantifying the degree of congestion.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.71201158,71671181)Hunan Province Social Science Achievement Evaluation Committee(2017,No.GLX195).
文摘This paper aims to measure the productivity of academic journals in the field of management science and operations research on the basis of a data envelopment analysis(DEA)-Malmquist approach.Using the empirical results,we make the following findings:(1)Compared with the DEA-CCR(Charnes,Cooper,Rhodes)model,the DEA-BCC(Banker,Charnes,Cooper)model may overestimate the performance of journals with a shorter cited half-life and fewer articles,and may underestimate the performance of journals with a longer cited half-life and more articles;(2)The average performance of journals in the management science and operations research field progressed by 1.8%during 2007-2014,which was a result of the frontier-shift effect;(3)The gap between the best journals on the DEA frontier and the rest of the journals is increasing because the best journals grow relatively faster;(4)High-level journals have made more progress and their performance is more stable,and the difference between high-level journals was also smaller during 2007-2014;and,(5)A higher total factor productivity value corresponds to higher Association of Business Schools rankings for certain journals.
基金supported by the National Natural Science Foundation of China (21875063 and 21871006)the Science and Technology Commission of Shanghai Municipality for Shanghai International Cooperation Program (19440710600)the Open Funding Project of the State Key Laboratory of Bioreactor Engineering。
文摘Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and superoxide radical(O^(-)_(2)) photogenerator(TB) against hypoxic tumors. TB particularly possessed a favorable O^(-)_(2) generation capability under 808 nm laser irradiation with the donoracceptor-donor(D-A-D) molecular structure. Moreover, owing to molecular rotation, potent hyperthermia was realized under continuous laser irradiation. For the usage of hypoxic tumor treatment, TB was encapsulated by a block copolymer,poly(ethylene glycol)-b-poly(latic acid)(PEG_(45)-b-PLA_(24)), to fabricate phototheranostic nanoparticles(TB NPs). Due to the twisted molecular structure and the shielding effect of long alkyl chains, the π-π stacking-induced quenching of O^(-)_(2) could be reduced after the fabrication of nano-assemblies. Significantly, TB NPs exhibited satisfactory O^(-)_(2) generation for type I PDT and a simultaneously distinct photothermal conversion efficiency(PCE, 62%) for photothermal therapy(PTT)to combat hypoxic tumor cells. Moreover, the high PCE endowed TB NPs with high-performance photoacoustic(PA)and photothermal imaging capability. In vivo experiments demonstrated that TB NPs possessed an outstanding phototherapeutic efficacy for eradicating hypoxic tumors. This study established a novel approach for constructing oxygenindependent phototherapeutic reagent against hypoxic tumors.
基金We would like to acknowledge the support of the National Natural Science Foundation of China(NSFC,Nos.71201158,71671181)The other supports of data and related materials from the Institutes of Science and Development,Chinese Academy of Sciences are also acknowledged.
文摘This studyfirst proposes a definition for directional congestion in certain input and output directions within the framework of data envelopment analysis.Second,two methods from different viewpoints are proposed to estimate the directional congestion.Third,we address the relationship between directional congestion and classic(strong or weak)congestion.Finally,we present a case study investigating the analysis performed by the research institutes of the Chinese Academy of Sciences to demonstrate the applicability and usefulness of the methods developed in this study.
