Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate asse...Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate assembly technique,utilizing Escherichia coli as the model organism.Through polymerase chain reaction(PCR)amplification,restriction enzyme digestion,ligation,transformation,and Sanger sequencing,we assessed the operational efficiency and cloning fidelity of both strategies.Our results demonstrated that Golden Gate assembly,leveraging type IIS restriction enzymes and simultaneous ligation,significantly enhanced cloning efficiency and precision,particularly for seamless multi-fragment assembly.In contrast,the classical cloning approach maintained certain advantages in simplicity and robustness for specific experimental conditions.Challenges encountered during transformation and sequencing highlighted the critical impact of technical accuracy on experimental outcomes.This study underscores the importance of selecting appropriate cloning methodologies tailored to experimental objectives and laboratory capabilities,providing a foundation for optimized molecular cloning workflows in future synthetic biology and biotechnology applications.展开更多
BACKGROUND:The nonspecifi c clinical presentation of adrenal insuffi ciency(AI)frequently leads to misdiagnosis,often as psychiatric or gastrointestinal disorders.AI is classifi ed anatomically as primary AI(PAI),seco...BACKGROUND:The nonspecifi c clinical presentation of adrenal insuffi ciency(AI)frequently leads to misdiagnosis,often as psychiatric or gastrointestinal disorders.AI is classifi ed anatomically as primary AI(PAI),secondary AI(SAI),or tertiary AI(TAI).Without timely recognition,progression to adrenal crisis(AC)can result in life-threatening outcomes.This study aimed to systematically analyze the clinical features,etiologies,and outcomes of AI in Lhasa’s emergency population to improve diagnostic accuracy and optimize clinical management.METHODS:A retrospective analysis of emergency department admissions from January 2020 to August 2024 at People’s Hospital of Xizang Autonomous Region was conducted.AI diagnoses were identifi ed via International Classifi cation of Diseases,Tenth Revision,Clinical Modifi cation(ICD-10-CM)codes from electronic health records(EHR).Patients were grouped into incipient AC(IAC)or AC cohorts based on hemodynamic status.Demographic profi les,etiologies,clinical presentations,and laboratory results were analyzed.RESULTS:Forty-three AI patients were identifi ed.The population-standardized admission rate for AI increased from 9 to 16 per million person-years,with PAI cases doubling during this period.Adrenal tuberculosis(58.1%)and adrenal hematoma(18.6%)were the leading etiologies.Compared to the IAC group,the AC group demonstrated lower systolic blood pressure(SBP)(P=0.001)and diastolic blood pressure(DBP)(P<0.001);higher neutrophil count(P=0.048),eosinophil count(P=0.044),CRP(P=0.004),blood urea nitrogen(BUN)(P=0.007);lower sodium(P<0.001)and glucose levels(P=0.001).The hospital stay was longer in the AC group(20 d vs.14 d;P<0.001).CONCLUSION:AI incidence is rising in high-altitude regions,with adrenal tuberculosis remaining the most common cause.AC is associated with increased inflammatory responses,hemodynamic instability,and metabolic disturbances.Targeted interventions are required to improve outcomes.展开更多
BACKGROUND:Neuroendocrine dysfunction after traumatic brain injury(TBI)has received increased attention due to its impact on the recovery of neural function.The purpose of this study is to investigate the incidence an...BACKGROUND:Neuroendocrine dysfunction after traumatic brain injury(TBI)has received increased attention due to its impact on the recovery of neural function.The purpose of this study is to investigate the incidence and risk factors of adrenocortical insuffi ciency(AI)after TBI to reveal independent predictors and build a prediction model of AI after TBI.METHODS:Enrolled patients were grouped into the AI and non-AI groups.Fourteen preset impact factors were recorded.Patients were regrouped according to each impact factor as a categorical variable.Univariate and multiple logistic regression analyses were performed to screen the related independent risk factors of AI after TBI and develop the predictive model.RESULTS:A total of 108 patients were recruited,of whom 34(31.5%)patients had AI.Nine factors(age,Glasgow Coma Scale[GCS]score on admission,mean arterial pressure[MAP],urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,diff use axonal injury[DAI],and skull base fracture)were probably related to AI after TBI.Three factors(urinary volume[X4],serum sodium level[X5],and DAI[X8])were independent variables,based on which a prediction model was developed(logit P=-3.552+2.583X4+2.235X5+2.269X8).CONCLUSIONS:The incidence of AI after TBI is high.Factors such as age,GCS score,MAP,urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,DAI,and skull base fracture are probably related to AI after TBI.Urinary volume,serum sodium level,and DAI are the independent predictors of AI after TBI.展开更多
BACKGROUND: The present study aimed to determine the short-term and long-term outcomes of critically ill patients with acute respiratory insuffi ciency who had received sedation or no sedation.METHODS: The data of 91 ...BACKGROUND: The present study aimed to determine the short-term and long-term outcomes of critically ill patients with acute respiratory insuffi ciency who had received sedation or no sedation.METHODS: The data of 91 patients who had received mechanical ventilation in the first 24 hours between November 2008 and October 2009 were retrospectively analyzed. These patients were divided into two groups: a sedation group(n=28) and a non-sedation group(n=63). The patients were also grouped in two groups: deep sedation group and daily interruption and /or light sedation group.RESULTS: Overall, the 91 patients who had received ventilation ≥48 hours were analyzed. Multivariate analysis demonstrated two independent risk factors for in-hospital death: sequential organ failure assessment score(P=0.019, RR 1.355, 95%CI 1.051–1.747, B=0.304, SE=0.130, Wald=50483) and sedation(P=0.041, RR 5.015, 95%CI 1.072–23.459, B=1.612, SE=0.787, Wald=4.195). Compared with the patients who had received no sedation, those who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and hospital, and an increased in-hospital mortality rate. The Kaplan-Meier method showed that patients who had received sedation had a lower 60-month survival rate than those who had received no sedation(76.7% vs. 88.9%, Log-rank test=3.630, P=0.057). Compared with the patients who had received deep sedation, those who had received daily interruption or light sedation showed a decreased in-hospital mortality rate(57.1% vs. 9.5%, P=0.008). The 60-month survival of the patients who had received deep sedation was signifi cantly lower than that of those who had daily interruption or light sedation(38.1% vs. 90.5%, Log-rank test=6.783, P=0.009).CONCLUSIONS: Sedation was associated with in-hospital death. The patients who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and in hospital, and an increased in-hospital mortality rate compared with the patients who did not receive sedation. Compared with daily interruption or light sedation, deep sedation increased the in-hospital mortality and decreased the 60-month survival for patients who had received sedation.展开更多
Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also i...Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management.展开更多
Prediction of the nutrient deficiency range and control of it through application of an appropriate amount of fertiliser at all growth stages is critical to achieving a qualitative and quantitative yield.Distributing f...Prediction of the nutrient deficiency range and control of it through application of an appropriate amount of fertiliser at all growth stages is critical to achieving a qualitative and quantitative yield.Distributing fertiliser in optimum amounts will protect the environment’s condition and human health risks.Early identification also prevents the disease’s occurrence in groundnut crops.A convo-lutional neural network is a computer vision algorithm that can be replaced in the place of human experts and laboratory methods to predict groundnut crop nitro-gen nutrient deficiency through image features.Since chlorophyll and nitrogen are proportionate to one another,the Smart Nutrient Deficiency Prediction System(SNDP)is proposed to detect and categorise the chlorophyll concentration range via which nitrogen concentration can be known.The model’sfirst part is to per-form preprocessing using Groundnut Leaf Image Preprocessing(GLIP).Then,in the second part,feature extraction using a convolution process with Non-negative ReLU(CNNR)is done,and then,in the third part,the extracted features areflat-tened and given to the dense layer(DL)layer.Next,the Maximum Margin clas-sifier(MMC)is deployed and takes the input from DL for the classification process tofind CCR.The dataset used in this work has no visible symptoms of a deficiency with three categories:low level(LL),beginning stage of low level(BSLL),and appropriate level(AL).This model could help to predict nitrogen deficiency before perceivable symptoms.The performance of the implemented model is analysed and compared with ImageNet pre-trained models.The result shows that the CNNR-MMC model obtained the highest training and validation accuracy of 99%and 95%,respectively,compared to existing pre-trained models.展开更多
Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in ...Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in different jurisdictions of Beijing from 2005 to 2015 was studied.The results showed that there were obvious differences between input-output efficiency of elements of urban construction land in different jurisdictions of Beijing,among which the efficiency of the core area of capital,Yanqing District,Fangshan District and Huairou District was relatively high,while the efficiency of Daxing District,Fengtai District and Miyun District was relatively low.There was no obvious correlation between efficiency differentiation and location factors,which is mainly caused by whether the land use in each jurisdiction has scale effect,whether the technology is improved,whether the input is redundant and whether the output is insufficient.For the jurisdiction of inefficient land use,we should strengthen the consciousness of intensive land use,improve the technical level,appropriately reduce the redundancy of input elements,and pay attention to the output of social and ecological benefits.展开更多
This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This s...This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This study analyzes the productivity of listed tourism companies from business and region aspects based on the calculation of Malmquist index. The results show that(1) the overall productivity is non-effi cient(0.954);(2) the productivity of accommodation and catering is biggest, which shows the tourism develops quickly with supports from technology;(3) the productivity in western China is highest, where the economy and tourism attraction are better than other regions; and(4) the effi ciency differences among the listed tourism companies are not signifi cant, and they attribute to the scale effi-ciency, that is the input of the fi nance, resource, talents and policy.展开更多
Nowadays,tungsten oxides,as a typical transition metal oxide,are widely and intensively investigated owing to their excellent material properties and device properties.Controlling oxygen defi ciency in tungsten oxides...Nowadays,tungsten oxides,as a typical transition metal oxide,are widely and intensively investigated owing to their excellent material properties and device properties.Controlling oxygen defi ciency in tungsten oxides is typically the key to enhance their performances for a variety of critical technological applications.With a gradual increase of oxygen defi ciency,various non-stoichiometric tungsten oxides can be formed by re-adjustment of the atomic arrangement,which exhibits superior performances than their traditional stoichiometric counterparts.This review mainly focuses on the recent advances in oxygen-defi cient tungsten oxides from the point of atomic structures,including the forming mechanism of non-stoichiometric tungsten oxides and the superiority of these oxygen-defi cient tungsten oxides in energy-related devices.Finally,the challenge and perspective of oxygen-defi cient tungsten oxides are also discussed.展开更多
Background:Adrenal insufficiency(AI)is a wellknown cause of potentially life-threatening disorders.Defects at each level of the hypothalamic-pituitary-adrenal axis can impair adrenal function,leading to varying degree...Background:Adrenal insufficiency(AI)is a wellknown cause of potentially life-threatening disorders.Defects at each level of the hypothalamic-pituitary-adrenal axis can impair adrenal function,leading to varying degrees of glucocorticoid(GC)deficiency.Iatrogenic AI induced by exogenous GCs is the most common cause of AI.The criteria for the diagnosis and management of iatrogenic AI,neonatal AI,and critical illness-related corticosteroid insuffi ciency(CIRCI)are not clear.Data sources:We reviewed the recent original publications and classical data from the literature,as well as the clinical,diagnostic and management strategies of pediatric AI.Results:Practical points in the diagnosis and management of AI with an emphasis on iatrogenic AI,neonatal AI,and CIRCI are provided.Given the lack of sensitive and practical biochemical tests for diagnosis of subtle AI,GC treatment has to be tailored to highly suggestive clinical symptoms and signs.Treatment of adrenal crisis is well standardized and patients almost invariably respond well to therapy.It is mainly the delay in treatment that is responsible for mortality in adrenal crisis.Conclusion:Education of patients and health care professionals is mandatory for timely interventions for patients with adrenal crisis.展开更多
High power efficiency and low efficiency roll-off at practical luminance are two requirements for new-generation energy-saving lighting technologies,which are still bottlenecks of thermally activated delayed fluoresce...High power efficiency and low efficiency roll-off at practical luminance are two requirements for new-generation energy-saving lighting technologies,which are still bottlenecks of thermally activated delayed fluorescence(TADF)white organic light-emitting diodes(WOLED),despite the advantages of TADF materials and devices in low cost and high sustainability.Herein,we developed a spiro phosphine oxide host named SSOXSPO,which can form multiple and multidirectional intermolecular hydrogen bonds(IHB).The resulted multilevel IHB network integrates long-range ordered and short-range disordered alignments for suppressing triplet-polaron quenching(TPQ)and triplet-triplet annihilation(TTA).Electronic characteristics of SSOXSPO matrix are further regulated,leading to the optimal exciton allocation through balancing energy and charge transfer.As consequence,using SSOXSPO as host,the single-emissive-layer TADF WOLEDs realized the record performance,including ultralow operation voltage as∼4.0 V,power efficiency beyond fluorescent tube(70.1 lm W−1)and negligible external quantum efficiency roll-off(3%)at 1000 nits for indoor lighting.This work demonstrates that multiple interplays supported by host matrixes in TADF WOLEDs can facilitate the synergistic effects of TADF emitters on 100%exciton utilization.展开更多
Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac...Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac is operated at the frequency of 53.667 MHz,which is the four times of the SSC operating frequency.In order to improve the longitudinal capture efficiency and increase the beam current extracted from the SSC,an independent multi-harmonics buncher(MHB)operating at a fundamental frequency of 13.417 MHz had been designed and manufactured.Method This buncher adopts the dual-gap structure and sawtooth waveform is generated by multi-harmonics synthetized technology.Beam dynamics simulation with MHB was carried out and discussed in this paper.Furthermore,the beam commissioning using 84Kr14+had been performed on SSC-Linac.Results and conclusion The measured maximum capture efficiency 86.5%was obtained,which was well agreed with the simulation results.Due to the successful commissioning of MHB and the outstanding-performance of SSC-Linac,the extracted beam current from SSC has been improved one order of magnitude higher than before.展开更多
Airline efficiency has been a research interest for decades.While early airline efficiency research focused primarily on revenue generation and profitability,growing airline social responsibility is driving greater inves...Airline efficiency has been a research interest for decades.While early airline efficiency research focused primarily on revenue generation and profitability,growing airline social responsibility is driving greater investment into understanding and improving the environmental impact on airline efficiency.This study developed a two-phase,two-stage model using a data envelopment analysis(DEA)approach to simultaneously evaluate airline operations for available seat mile(ASM)generation,revenue passenger mile(RPM)generation,carbon dioxide emissions abatement,and revenue generation on a sample of thirteen airlines.Efficiency evaluation was performed for the years between 2013 and 2015,between U.S.and non-U.S.carriers,and between full-service carriers(FSCs)and low-cost carriers(LCCs).Results indicated more accurate measurement of airlines’overall efficiency using the proposed DEA model,which included operational and cost factors as input variables and environmental impact as both the input and output variables in the model.Service and environmentalfactors were found to be significantin determining airline efficiency,with environmental abatement affecting the overall efficiency of airline performance both inside and outside the U.S.when emission reduction effort was properly accounted for.Thefindings provided theoretical and managerial implications in the assessment of airline efficiency with a special emphasis on incorporating environmental impact in the overall evaluation.展开更多
In summer, Cha No. 39 of 292 bags and 205 of 244 bags were inter- planted with Dendrobium officinale on cultivation bed, respectively, whose yields and biological efficiencies reached 102.46 kg and 103.98%, and 96.77 ...In summer, Cha No. 39 of 292 bags and 205 of 244 bags were inter- planted with Dendrobium officinale on cultivation bed, respectively, whose yields and biological efficiencies reached 102.46 kg and 103.98%, and 96.77 kg and 113.32%, accordingly. The seedlings of Dendrobium officinale interplanted with Pleurotus os- treatus grew by 2.78 cm during 10 weeks on cultivation beds, and the seedlings grew by 2.68 cm in the cultivation beds without interplanting arrangement. These demonstrated that the interplanting of Dendrobium officinale and Pleurotus ostreatus has none adverse effects on growth of Dendrobium officinale.展开更多
Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is emp...Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.展开更多
This study performs a novel control effi ciency assessment approach that compares performance of optimal control algorithms regarding vibration of tensegrity structures. Due to complex loading conditions and the inher...This study performs a novel control effi ciency assessment approach that compares performance of optimal control algorithms regarding vibration of tensegrity structures. Due to complex loading conditions and the inherent characteristics of tensegrities, e.g. geometrical nonlinearity, the quantization of control effi ciency in active control of tensegrity constitutes a challenging task especially for diff erent control algorithms. As a fi rst step, an actuator energy input, comprising the strain energy of tensegrity elements and their internal forces work, is set to constant levels for the linearquadratic regulator (LQR). Afterwards, the actuator energy of the linear-quadratic Gaussian (LQG) is iterated with identical actuator energy input in LQR. A double layer tensegrity grid is employed to compare the control effi ciencies between LQR and LQG with fi ve diff erent control scenarios. The results demonstrate the effi ciency and robustness in reducing the dynamic response of tensegrity structures, and a theoretical guideline is provided to search optimal control options in controlling actual tensegrities.展开更多
Celiac disease(CD) is now recognized as a common disorder among Middle Eastern(ME) and North African(NA) populations.The aim of this review is to assess the available data regarding CD in the ME and NA and to compare ...Celiac disease(CD) is now recognized as a common disorder among Middle Eastern(ME) and North African(NA) populations.The aim of this review is to assess the available data regarding CD in the ME and NA and to compare this information with that of Western countries.A literature review was performed using the electronic databases PubMed and Medline(1950-2008) as search engines,and "celiac disease" was used as a Mesh term.The search was limited to ME and NA countries.The prevalence of CD in ME and NA countries among low risk populations is similar to that of Western countries,but is higher in high risk populations such as those with type 1 diabetes.It is underestimated because of lack of clinical suspicion and lack of patient awareness.Clinical presentations in term of gastrointestinal,hematologic,skeletal,and liver manifestations are similar between both populations except for a high prevalence of short stature in some ME and NA countries.Few studies have addressed atypical or silent CD.As in the West,diagnosis is initially made by serological tests and is confirmed by small intestinal biopsies.Gluten-free diet is the main mode of treatment with a higher apparent adherence rate than in the West.Most disease complications result from malabsorption.The disease is strongly associated with HLA DQ2 and to a lesser extent with HLA DQ8 alleles.In conclusion,CD prevalence is underestimated,with little data available about its malignant complications.Disease parameters in the ME and NA are otherwise similar to those in Western countries.展开更多
Lithium,as the lightest and lowest potential metal,is an ideal "battery metal" and the core strategic metal of the new energy industry revolution.Recovering lithium from spent lithium batteries(LIBs)has beco...Lithium,as the lightest and lowest potential metal,is an ideal "battery metal" and the core strategic metal of the new energy industry revolution.Recovering lithium from spent lithium batteries(LIBs)has become one of the significant approaches to obtaining lithium resources.At present,the lithium extraction being generally placed at the last step of the spent LIBs recovery process has puzzles such as high acid consumption,low Li recovery purity and low recovery efficiency.Selective lithium extraction at the first step of the recovery process can effectively solve those puzzles.Since lithium leaching is a non-spontaneous reaction requiring additional energy to achieve,it is found that these methods can be divided into five ways according to the different types of energy driving the reaction occurring:(ⅰ)electric energy driving lithium extraction;(ⅱ) chemical energy driving lithium extraction;(ⅲ) mechanical energy driving lithium extraction;(ⅳ) thermal energy driving lithium extraction;(ⅴ) other energy driving lithium extraction.Through the analysis of the principle,reaction process and results of recovering lithium methods can provide a few directions for scholars’ subsequent research.It is necessary to speed up the exploration of the principle of these methods.It is expected that this study could provide a reference for the research on the selective lithium extraction.展开更多
A mass-balanced Ecopath model presents a quantitative description of the trophic structure,fl ow of energy and trophic interaction among ecological groups of an ecosystem.The Ecopath with Ecosim(EwE)modeling program(V...A mass-balanced Ecopath model presents a quantitative description of the trophic structure,fl ow of energy and trophic interaction among ecological groups of an ecosystem.The Ecopath with Ecosim(EwE)modeling program(Version 6.5)was used to develop a preliminary trophic model for a tropical freshwater reservoir.The total fi sh biomass was 6.245 t/km 2 and the highest trophic level of the reservoir was 3.362(for snakehead).The ecosystem is phytoplankton based because primary producers originated 68%and detritus originated 32%of the total fl ow from lower trophic level.The gross effi ciency of the fi shery was 0.004,suggesting the ineffi ciency of the system.The positive eff ect of phytoplankton and detritus on most of the other groups were evident from mixed trophic analysis while moderately higher ecotrophic effi ciency(EE)of phytoplankton shows the ecosystem’s potential bottom-up control.The competition for the same resources among diff erent groups was also obvious.The ratio of primary production/respiration(1.969)suggests that the ecosystem is at the developing stage and utmost contemplation should be given to concerned human activities.The low value of relative ascendancy(30.13)and overhead(69.87)reveals the stability of the ecosystem and some degrees of maturity.It also predicts the presence of signifi cant strength in reserve of the system to withstand or overcome any perturbation.However,ecologically sustainable resource management plans should be implemented to ensure the sustainability of this reservoir resources.展开更多
Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are ...Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem function.There are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type reservoir.The comparative analysis of phytoplankton community stability between the two types of reservoir has not been reported.Jiuquwan Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the Dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation vs.new impoundment,river-type vs.lake-type,and shallow water vs.sub-deep water reservoirs.Samples were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were examined.Results show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the reservoir.There was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type reservoir.In addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both reservoirs.The increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stability was aff ected by both biotic and abiotic factors,and hydrodynamic index was the main factor.This study is helpful to understand the relationship and diff erences in phytoplankton diversity,productivity and community stability in diff erent types of reservoirs,and provides a guidance for maintaining the stability of reservoir water ecosystem and protecting the biodiversity.The relationships between phytoplankton diversity,productivity,and community stability will be investigated in depth,for which a long-term observation will be conducted on the impact of environmental factors and diversity on the local biostability in diff erent types of reservoirs.展开更多
文摘Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate assembly technique,utilizing Escherichia coli as the model organism.Through polymerase chain reaction(PCR)amplification,restriction enzyme digestion,ligation,transformation,and Sanger sequencing,we assessed the operational efficiency and cloning fidelity of both strategies.Our results demonstrated that Golden Gate assembly,leveraging type IIS restriction enzymes and simultaneous ligation,significantly enhanced cloning efficiency and precision,particularly for seamless multi-fragment assembly.In contrast,the classical cloning approach maintained certain advantages in simplicity and robustness for specific experimental conditions.Challenges encountered during transformation and sequencing highlighted the critical impact of technical accuracy on experimental outcomes.This study underscores the importance of selecting appropriate cloning methodologies tailored to experimental objectives and laboratory capabilities,providing a foundation for optimized molecular cloning workflows in future synthetic biology and biotechnology applications.
基金supported by grants from the National Natural Science Foundation of China(82241052)Natural Science Foundation of Xizang Autonomous Region(XZZR202402133[W])Peking University People’s Hospital Scientifi c Research Development Funds(RDJP2023-29).
文摘BACKGROUND:The nonspecifi c clinical presentation of adrenal insuffi ciency(AI)frequently leads to misdiagnosis,often as psychiatric or gastrointestinal disorders.AI is classifi ed anatomically as primary AI(PAI),secondary AI(SAI),or tertiary AI(TAI).Without timely recognition,progression to adrenal crisis(AC)can result in life-threatening outcomes.This study aimed to systematically analyze the clinical features,etiologies,and outcomes of AI in Lhasa’s emergency population to improve diagnostic accuracy and optimize clinical management.METHODS:A retrospective analysis of emergency department admissions from January 2020 to August 2024 at People’s Hospital of Xizang Autonomous Region was conducted.AI diagnoses were identifi ed via International Classifi cation of Diseases,Tenth Revision,Clinical Modifi cation(ICD-10-CM)codes from electronic health records(EHR).Patients were grouped into incipient AC(IAC)or AC cohorts based on hemodynamic status.Demographic profi les,etiologies,clinical presentations,and laboratory results were analyzed.RESULTS:Forty-three AI patients were identifi ed.The population-standardized admission rate for AI increased from 9 to 16 per million person-years,with PAI cases doubling during this period.Adrenal tuberculosis(58.1%)and adrenal hematoma(18.6%)were the leading etiologies.Compared to the IAC group,the AC group demonstrated lower systolic blood pressure(SBP)(P=0.001)and diastolic blood pressure(DBP)(P<0.001);higher neutrophil count(P=0.048),eosinophil count(P=0.044),CRP(P=0.004),blood urea nitrogen(BUN)(P=0.007);lower sodium(P<0.001)and glucose levels(P=0.001).The hospital stay was longer in the AC group(20 d vs.14 d;P<0.001).CONCLUSION:AI incidence is rising in high-altitude regions,with adrenal tuberculosis remaining the most common cause.AC is associated with increased inflammatory responses,hemodynamic instability,and metabolic disturbances.Targeted interventions are required to improve outcomes.
基金a grant from the National Clinical Specialty Construction Project of China(2013-544).
文摘BACKGROUND:Neuroendocrine dysfunction after traumatic brain injury(TBI)has received increased attention due to its impact on the recovery of neural function.The purpose of this study is to investigate the incidence and risk factors of adrenocortical insuffi ciency(AI)after TBI to reveal independent predictors and build a prediction model of AI after TBI.METHODS:Enrolled patients were grouped into the AI and non-AI groups.Fourteen preset impact factors were recorded.Patients were regrouped according to each impact factor as a categorical variable.Univariate and multiple logistic regression analyses were performed to screen the related independent risk factors of AI after TBI and develop the predictive model.RESULTS:A total of 108 patients were recruited,of whom 34(31.5%)patients had AI.Nine factors(age,Glasgow Coma Scale[GCS]score on admission,mean arterial pressure[MAP],urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,diff use axonal injury[DAI],and skull base fracture)were probably related to AI after TBI.Three factors(urinary volume[X4],serum sodium level[X5],and DAI[X8])were independent variables,based on which a prediction model was developed(logit P=-3.552+2.583X4+2.235X5+2.269X8).CONCLUSIONS:The incidence of AI after TBI is high.Factors such as age,GCS score,MAP,urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,DAI,and skull base fracture are probably related to AI after TBI.Urinary volume,serum sodium level,and DAI are the independent predictors of AI after TBI.
文摘BACKGROUND: The present study aimed to determine the short-term and long-term outcomes of critically ill patients with acute respiratory insuffi ciency who had received sedation or no sedation.METHODS: The data of 91 patients who had received mechanical ventilation in the first 24 hours between November 2008 and October 2009 were retrospectively analyzed. These patients were divided into two groups: a sedation group(n=28) and a non-sedation group(n=63). The patients were also grouped in two groups: deep sedation group and daily interruption and /or light sedation group.RESULTS: Overall, the 91 patients who had received ventilation ≥48 hours were analyzed. Multivariate analysis demonstrated two independent risk factors for in-hospital death: sequential organ failure assessment score(P=0.019, RR 1.355, 95%CI 1.051–1.747, B=0.304, SE=0.130, Wald=50483) and sedation(P=0.041, RR 5.015, 95%CI 1.072–23.459, B=1.612, SE=0.787, Wald=4.195). Compared with the patients who had received no sedation, those who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and hospital, and an increased in-hospital mortality rate. The Kaplan-Meier method showed that patients who had received sedation had a lower 60-month survival rate than those who had received no sedation(76.7% vs. 88.9%, Log-rank test=3.630, P=0.057). Compared with the patients who had received deep sedation, those who had received daily interruption or light sedation showed a decreased in-hospital mortality rate(57.1% vs. 9.5%, P=0.008). The 60-month survival of the patients who had received deep sedation was signifi cantly lower than that of those who had daily interruption or light sedation(38.1% vs. 90.5%, Log-rank test=6.783, P=0.009).CONCLUSIONS: Sedation was associated with in-hospital death. The patients who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and in hospital, and an increased in-hospital mortality rate compared with the patients who did not receive sedation. Compared with daily interruption or light sedation, deep sedation increased the in-hospital mortality and decreased the 60-month survival for patients who had received sedation.
文摘Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management.
文摘Prediction of the nutrient deficiency range and control of it through application of an appropriate amount of fertiliser at all growth stages is critical to achieving a qualitative and quantitative yield.Distributing fertiliser in optimum amounts will protect the environment’s condition and human health risks.Early identification also prevents the disease’s occurrence in groundnut crops.A convo-lutional neural network is a computer vision algorithm that can be replaced in the place of human experts and laboratory methods to predict groundnut crop nitro-gen nutrient deficiency through image features.Since chlorophyll and nitrogen are proportionate to one another,the Smart Nutrient Deficiency Prediction System(SNDP)is proposed to detect and categorise the chlorophyll concentration range via which nitrogen concentration can be known.The model’sfirst part is to per-form preprocessing using Groundnut Leaf Image Preprocessing(GLIP).Then,in the second part,feature extraction using a convolution process with Non-negative ReLU(CNNR)is done,and then,in the third part,the extracted features areflat-tened and given to the dense layer(DL)layer.Next,the Maximum Margin clas-sifier(MMC)is deployed and takes the input from DL for the classification process tofind CCR.The dataset used in this work has no visible symptoms of a deficiency with three categories:low level(LL),beginning stage of low level(BSLL),and appropriate level(AL).This model could help to predict nitrogen deficiency before perceivable symptoms.The performance of the implemented model is analysed and compared with ImageNet pre-trained models.The result shows that the CNNR-MMC model obtained the highest training and validation accuracy of 99%and 95%,respectively,compared to existing pre-trained models.
文摘Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in different jurisdictions of Beijing from 2005 to 2015 was studied.The results showed that there were obvious differences between input-output efficiency of elements of urban construction land in different jurisdictions of Beijing,among which the efficiency of the core area of capital,Yanqing District,Fangshan District and Huairou District was relatively high,while the efficiency of Daxing District,Fengtai District and Miyun District was relatively low.There was no obvious correlation between efficiency differentiation and location factors,which is mainly caused by whether the land use in each jurisdiction has scale effect,whether the technology is improved,whether the input is redundant and whether the output is insufficient.For the jurisdiction of inefficient land use,we should strengthen the consciousness of intensive land use,improve the technical level,appropriately reduce the redundancy of input elements,and pay attention to the output of social and ecological benefits.
基金supported by the project of Shaanxi Normal University(Grant No.999521)Xianyang Normal University(Grant Nos.11XSYK316,201002001)
文摘This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This study analyzes the productivity of listed tourism companies from business and region aspects based on the calculation of Malmquist index. The results show that(1) the overall productivity is non-effi cient(0.954);(2) the productivity of accommodation and catering is biggest, which shows the tourism develops quickly with supports from technology;(3) the productivity in western China is highest, where the economy and tourism attraction are better than other regions; and(4) the effi ciency differences among the listed tourism companies are not signifi cant, and they attribute to the scale effi-ciency, that is the input of the fi nance, resource, talents and policy.
基金supported by the National Natural Science Foundation of China(No.61904080)the Macao Young Scholars Program of China(No.AM2020005)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110994).
文摘Nowadays,tungsten oxides,as a typical transition metal oxide,are widely and intensively investigated owing to their excellent material properties and device properties.Controlling oxygen defi ciency in tungsten oxides is typically the key to enhance their performances for a variety of critical technological applications.With a gradual increase of oxygen defi ciency,various non-stoichiometric tungsten oxides can be formed by re-adjustment of the atomic arrangement,which exhibits superior performances than their traditional stoichiometric counterparts.This review mainly focuses on the recent advances in oxygen-defi cient tungsten oxides from the point of atomic structures,including the forming mechanism of non-stoichiometric tungsten oxides and the superiority of these oxygen-defi cient tungsten oxides in energy-related devices.Finally,the challenge and perspective of oxygen-defi cient tungsten oxides are also discussed.
文摘Background:Adrenal insufficiency(AI)is a wellknown cause of potentially life-threatening disorders.Defects at each level of the hypothalamic-pituitary-adrenal axis can impair adrenal function,leading to varying degrees of glucocorticoid(GC)deficiency.Iatrogenic AI induced by exogenous GCs is the most common cause of AI.The criteria for the diagnosis and management of iatrogenic AI,neonatal AI,and critical illness-related corticosteroid insuffi ciency(CIRCI)are not clear.Data sources:We reviewed the recent original publications and classical data from the literature,as well as the clinical,diagnostic and management strategies of pediatric AI.Results:Practical points in the diagnosis and management of AI with an emphasis on iatrogenic AI,neonatal AI,and CIRCI are provided.Given the lack of sensitive and practical biochemical tests for diagnosis of subtle AI,GC treatment has to be tailored to highly suggestive clinical symptoms and signs.Treatment of adrenal crisis is well standardized and patients almost invariably respond well to therapy.It is mainly the delay in treatment that is responsible for mortality in adrenal crisis.Conclusion:Education of patients and health care professionals is mandatory for timely interventions for patients with adrenal crisis.
基金Natural Science Foundation of China,Grant/Award Numbers:92061205,62175060,51873056,61905070,22005088Changjiang Scholar Program of Chinese Ministry of Education,Grant/Award Number:Q2021256Natural Science Fund for Excellent Young Scholars of Heilongjiang Province,Grant/Award Numbers:YQ2020B006,YQ2022B010。
文摘High power efficiency and low efficiency roll-off at practical luminance are two requirements for new-generation energy-saving lighting technologies,which are still bottlenecks of thermally activated delayed fluorescence(TADF)white organic light-emitting diodes(WOLED),despite the advantages of TADF materials and devices in low cost and high sustainability.Herein,we developed a spiro phosphine oxide host named SSOXSPO,which can form multiple and multidirectional intermolecular hydrogen bonds(IHB).The resulted multilevel IHB network integrates long-range ordered and short-range disordered alignments for suppressing triplet-polaron quenching(TPQ)and triplet-triplet annihilation(TTA).Electronic characteristics of SSOXSPO matrix are further regulated,leading to the optimal exciton allocation through balancing energy and charge transfer.As consequence,using SSOXSPO as host,the single-emissive-layer TADF WOLEDs realized the record performance,including ultralow operation voltage as∼4.0 V,power efficiency beyond fluorescent tube(70.1 lm W−1)and negligible external quantum efficiency roll-off(3%)at 1000 nits for indoor lighting.This work demonstrates that multiple interplays supported by host matrixes in TADF WOLEDs can facilitate the synergistic effects of TADF emitters on 100%exciton utilization.
基金supported by the National Natural Science Foundation of China(No.11375243)Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06G373).
文摘Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac is operated at the frequency of 53.667 MHz,which is the four times of the SSC operating frequency.In order to improve the longitudinal capture efficiency and increase the beam current extracted from the SSC,an independent multi-harmonics buncher(MHB)operating at a fundamental frequency of 13.417 MHz had been designed and manufactured.Method This buncher adopts the dual-gap structure and sawtooth waveform is generated by multi-harmonics synthetized technology.Beam dynamics simulation with MHB was carried out and discussed in this paper.Furthermore,the beam commissioning using 84Kr14+had been performed on SSC-Linac.Results and conclusion The measured maximum capture efficiency 86.5%was obtained,which was well agreed with the simulation results.Due to the successful commissioning of MHB and the outstanding-performance of SSC-Linac,the extracted beam current from SSC has been improved one order of magnitude higher than before.
文摘Airline efficiency has been a research interest for decades.While early airline efficiency research focused primarily on revenue generation and profitability,growing airline social responsibility is driving greater investment into understanding and improving the environmental impact on airline efficiency.This study developed a two-phase,two-stage model using a data envelopment analysis(DEA)approach to simultaneously evaluate airline operations for available seat mile(ASM)generation,revenue passenger mile(RPM)generation,carbon dioxide emissions abatement,and revenue generation on a sample of thirteen airlines.Efficiency evaluation was performed for the years between 2013 and 2015,between U.S.and non-U.S.carriers,and between full-service carriers(FSCs)and low-cost carriers(LCCs).Results indicated more accurate measurement of airlines’overall efficiency using the proposed DEA model,which included operational and cost factors as input variables and environmental impact as both the input and output variables in the model.Service and environmentalfactors were found to be significantin determining airline efficiency,with environmental abatement affecting the overall efficiency of airline performance both inside and outside the U.S.when emission reduction effort was properly accounted for.Thefindings provided theoretical and managerial implications in the assessment of airline efficiency with a special emphasis on incorporating environmental impact in the overall evaluation.
基金Supported by Fundamental Research Funds for Guangxi Academy of Sciences(13YJ22SWS20)~~
文摘In summer, Cha No. 39 of 292 bags and 205 of 244 bags were inter- planted with Dendrobium officinale on cultivation bed, respectively, whose yields and biological efficiencies reached 102.46 kg and 103.98%, and 96.77 kg and 113.32%, accordingly. The seedlings of Dendrobium officinale interplanted with Pleurotus os- treatus grew by 2.78 cm during 10 weeks on cultivation beds, and the seedlings grew by 2.68 cm in the cultivation beds without interplanting arrangement. These demonstrated that the interplanting of Dendrobium officinale and Pleurotus ostreatus has none adverse effects on growth of Dendrobium officinale.
基金National Natural Science Foundation of China under Grant Nos.51725901 and 51639006
文摘Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.
基金Natural Science Foundation of Zhejiang Province under Grant No.LQ19E080013the International Scientific and Technological Cooperation Projects of Shaoxing University under Grant No.2019LGGH1005
文摘This study performs a novel control effi ciency assessment approach that compares performance of optimal control algorithms regarding vibration of tensegrity structures. Due to complex loading conditions and the inherent characteristics of tensegrities, e.g. geometrical nonlinearity, the quantization of control effi ciency in active control of tensegrity constitutes a challenging task especially for diff erent control algorithms. As a fi rst step, an actuator energy input, comprising the strain energy of tensegrity elements and their internal forces work, is set to constant levels for the linearquadratic regulator (LQR). Afterwards, the actuator energy of the linear-quadratic Gaussian (LQG) is iterated with identical actuator energy input in LQR. A double layer tensegrity grid is employed to compare the control effi ciencies between LQR and LQG with fi ve diff erent control scenarios. The results demonstrate the effi ciency and robustness in reducing the dynamic response of tensegrity structures, and a theoretical guideline is provided to search optimal control options in controlling actual tensegrities.
文摘Celiac disease(CD) is now recognized as a common disorder among Middle Eastern(ME) and North African(NA) populations.The aim of this review is to assess the available data regarding CD in the ME and NA and to compare this information with that of Western countries.A literature review was performed using the electronic databases PubMed and Medline(1950-2008) as search engines,and "celiac disease" was used as a Mesh term.The search was limited to ME and NA countries.The prevalence of CD in ME and NA countries among low risk populations is similar to that of Western countries,but is higher in high risk populations such as those with type 1 diabetes.It is underestimated because of lack of clinical suspicion and lack of patient awareness.Clinical presentations in term of gastrointestinal,hematologic,skeletal,and liver manifestations are similar between both populations except for a high prevalence of short stature in some ME and NA countries.Few studies have addressed atypical or silent CD.As in the West,diagnosis is initially made by serological tests and is confirmed by small intestinal biopsies.Gluten-free diet is the main mode of treatment with a higher apparent adherence rate than in the West.Most disease complications result from malabsorption.The disease is strongly associated with HLA DQ2 and to a lesser extent with HLA DQ8 alleles.In conclusion,CD prevalence is underestimated,with little data available about its malignant complications.Disease parameters in the ME and NA are otherwise similar to those in Western countries.
基金financially supported by the National Key Research and Development Program of China(2019YFC1907900)the Key Project of Research and Development Plan of Jiangxi Province(20201BBE51007)the National Science Fund for Distinguished Young Scholars(52125002)。
文摘Lithium,as the lightest and lowest potential metal,is an ideal "battery metal" and the core strategic metal of the new energy industry revolution.Recovering lithium from spent lithium batteries(LIBs)has become one of the significant approaches to obtaining lithium resources.At present,the lithium extraction being generally placed at the last step of the spent LIBs recovery process has puzzles such as high acid consumption,low Li recovery purity and low recovery efficiency.Selective lithium extraction at the first step of the recovery process can effectively solve those puzzles.Since lithium leaching is a non-spontaneous reaction requiring additional energy to achieve,it is found that these methods can be divided into five ways according to the different types of energy driving the reaction occurring:(ⅰ)electric energy driving lithium extraction;(ⅱ) chemical energy driving lithium extraction;(ⅲ) mechanical energy driving lithium extraction;(ⅳ) thermal energy driving lithium extraction;(ⅴ) other energy driving lithium extraction.Through the analysis of the principle,reaction process and results of recovering lithium methods can provide a few directions for scholars’ subsequent research.It is necessary to speed up the exploration of the principle of these methods.It is expected that this study could provide a reference for the research on the selective lithium extraction.
文摘A mass-balanced Ecopath model presents a quantitative description of the trophic structure,fl ow of energy and trophic interaction among ecological groups of an ecosystem.The Ecopath with Ecosim(EwE)modeling program(Version 6.5)was used to develop a preliminary trophic model for a tropical freshwater reservoir.The total fi sh biomass was 6.245 t/km 2 and the highest trophic level of the reservoir was 3.362(for snakehead).The ecosystem is phytoplankton based because primary producers originated 68%and detritus originated 32%of the total fl ow from lower trophic level.The gross effi ciency of the fi shery was 0.004,suggesting the ineffi ciency of the system.The positive eff ect of phytoplankton and detritus on most of the other groups were evident from mixed trophic analysis while moderately higher ecotrophic effi ciency(EE)of phytoplankton shows the ecosystem’s potential bottom-up control.The competition for the same resources among diff erent groups was also obvious.The ratio of primary production/respiration(1.969)suggests that the ecosystem is at the developing stage and utmost contemplation should be given to concerned human activities.The low value of relative ascendancy(30.13)and overhead(69.87)reveals the stability of the ecosystem and some degrees of maturity.It also predicts the presence of signifi cant strength in reserve of the system to withstand or overcome any perturbation.However,ecologically sustainable resource management plans should be implemented to ensure the sustainability of this reservoir resources.
基金Supported by the Key Research and Development Program of Guangdong Province(No.2019B110205004)the Science and Technology Foundation of Guizhou Province(Nos.[2020]4Y009,[2020]6009)。
文摘Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem function.There are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type reservoir.The comparative analysis of phytoplankton community stability between the two types of reservoir has not been reported.Jiuquwan Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the Dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation vs.new impoundment,river-type vs.lake-type,and shallow water vs.sub-deep water reservoirs.Samples were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were examined.Results show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the reservoir.There was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type reservoir.In addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both reservoirs.The increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stability was aff ected by both biotic and abiotic factors,and hydrodynamic index was the main factor.This study is helpful to understand the relationship and diff erences in phytoplankton diversity,productivity and community stability in diff erent types of reservoirs,and provides a guidance for maintaining the stability of reservoir water ecosystem and protecting the biodiversity.The relationships between phytoplankton diversity,productivity,and community stability will be investigated in depth,for which a long-term observation will be conducted on the impact of environmental factors and diversity on the local biostability in diff erent types of reservoirs.
