A habitat model has been widely used to manage marine species and analyze relationship between species distribution and environmental factors.The predictive skill in habitat model depends on whether the models include...A habitat model has been widely used to manage marine species and analyze relationship between species distribution and environmental factors.The predictive skill in habitat model depends on whether the models include appropriate explanatory variables.Due to limited habitat range,low density,and low detection rate,the number of zero catches could be very large even in favorable habitats.Excessive zeroes will increase the bias and uncertainty in estimation of habitat.Therefore,appropriate explanatory variables need to be chosen first to prevent underestimate or overestimate species abundance in habitat models.In addition,biotic variables such as prey data and spatial autocovariate(SAC)of target species are often ignored in species distribution models.Therefore,we evaluated the eff ects of input variables on the performance of generalized additive models(GAMs)under excessive zero catch(>70%).Five types of input variables were selected,i.e.,(1)abiotic variables,(2)abiotic and biotic variables,(3)abiotic variables and SAC,(4)abiotic,biotic variables and SAC,and(5)principal component analysis(PCA)based abiotic and biotic variables and SAC.Belanger’s croaker Johnius belangerii is one of the dominant demersal fish in Haizhou Bay,with a large number of zero catches,thus was used for the case study.Results show that the PCA-based GAM incorporated with abiotic and biotic variables and SAC was the most appropriate model to quantify the spatial distribution of the croaker.Biotic variables and SAC were important and should be incorporated as one of the drivers to predict species distribution.Our study suggests that the process of input variables is critical to habitat modelling,which could improve the performance of habitat models and enhance our understanding of the habitat suitability of target species.展开更多
Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interacti...Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.展开更多
New coronavirus pneumonia spread rapidly all over the world in the first half of 2020, which is a new respiratory disease with strong infectiousness. At present, the epidemic situation in China has been effectively co...New coronavirus pneumonia spread rapidly all over the world in the first half of 2020, which is a new respiratory disease with strong infectiousness. At present, the epidemic situation in China has been effectively controlled, but the global epidemic situation remains grim, and the National Health Commission has instructed that the prevention and control of new coronavirus pneumonia should become normalized. As outposts for surveillance of public health events, hospitals are an important front in the fight against the epidemic. Therefore, it is very crucial to construct infection prevention and control system actively to contain the outbreak. This paper analyzes and summarizes the normal prevention and control management strategy of Infection Control Branch Management (hereinafter referred to as Hospital Infection-Control Dept) in a certain designated comprehensive third-grade hospital in Guangdong Province and transforms the prevention and control means in emergency state into measures for sustainable development, which also provides basis and reference for Hospital Infection-Control Dept of medical institutions to formulate prevention and control guidelines.展开更多
The density functional theory was used to investigate the adsorption of CH_4 and H_2O on different rank coal surfaces.The coal rank is the dominant factor in affecting the adsorption capacity of coal.In order to bette...The density functional theory was used to investigate the adsorption of CH_4 and H_2O on different rank coal surfaces.The coal rank is the dominant factor in affecting the adsorption capacity of coal.In order to better understand gas and water interaction with coal of different maturity,we developed fourteen coal models to represent the different rank coal.The interactions of CH_4 and H_2O with coal surfaces were studied and characterized by their adsorption energies,Mulliken charges and electrostatic potential surfaces.The results revealed that the interaction between coal and CH_4 was weak physical adsorption,and that the interaction between coal and H_2 O consisted of physical and chemical adsorption.Adsorption energy of coal–H_2O system was larger than that of coal–CH_4 on all rank coals,suggesting that the adsorption priority in the coal models is H_2 O > CH_4.Consequently,the injection of H_2 O into the different rank coal could effectively enhance the coal bed methane(CBM) recovery.展开更多
BACKGROUND Single incision plus one port left-side approach(SILS+1/L)totally laparoscopic distal gastrectomy(TLDG)is an emerging technique for the treatment of gastric cancer.Reduced port laparoscopic gastrectomy has ...BACKGROUND Single incision plus one port left-side approach(SILS+1/L)totally laparoscopic distal gastrectomy(TLDG)is an emerging technique for the treatment of gastric cancer.Reduced port laparoscopic gastrectomy has a number of potential advantages for patients compared with conventional laparoscopic gastrectomy:relieving postoperative pain,shortening hospital stay and offering a better cosmetic outcome.Nevertheless,there are no previous reports on the use of SILS+1/L TLDG with uncut Roux-en-Y(uncut R-Y)reconstruction.AIM To investigate the initial feasibility of SILS+1/L TLDG with uncut Roux-en-Y digestive tract reconstruction(uncut R-Y reconstruction)to treat distal gastric cancer.METHODS A total of 21 patients who underwent SILS+1/L TLDG with uncut R-Y reconstruction for gastric cancer were enrolled.All patients were treated at The Second Hospital of Shandong University.Reconstructions were performed intracorporeally with 60 mm endoscopic linear stapler and 45 mm no-knife stapler.The clinicopathological characteristics,surgical details,postoperative short-term outcomes,postoperative follow-up upper gastrointestinal radiography findings and endoscopy results were analyzed retrospectively.RESULTS All SILS+1/L operations were performed by SILS+1/L TLDG successfully.The patient population included 13 men and 8 women with a mean age of 48.2 years(ranged from 40 years to 70 years)and median body mass index of 22.8 kg/m^2.There were no conversions to open laparotomy,and no other port was placed.The mean operation time was 146 min(ranged 130-180 min),and the estimated mean blood loss was 54 mL(ranged 20-110 mL).The mean duration to flatus and discharge was 2.3(ranged 1-3.5)and 7.3(ranged 6-9)d,respectively.The mean number of retrieved lymph nodes was 42(ranged 30-47).Two patients experienced mild postoperative complications,including surgical site infection(wound at the navel incision)and mild postoperative pancreatic fistula(grade A).Follow-up upper gastrointestinal radiography and endoscopy were carried out at 3 mo postoperatively.No patients experienced moderate or severe food stasis,alkaline gastritis or bile reflux during the follow-up period.No recanalization of the biliopancreatic limb was found.CONCLUSION SILS+1/L TLDG with uncut R-Y reconstruction could be safely performed as a reduced port surgery.展开更多
Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abu...Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abundance to each environmental variable is different and habitat requirements may change over life history stages and seasons.Therefore,it is necessary to determine the optimal combination of environmental variables in HSI modelling.In this study,generalized additive models(GAMs)were used to determine which environmental variables to be included in the HSI models.Significant variables were retained and weighted in the HSI model according to their relative contribution(%)to the total deviation explained by the boosted regression tree(BRT).The HSI models were applied to evaluate the habitat suitability of mantis shrimp Oratosquilla oratoria in the Haizhou Bay and adjacent areas in 2011 and 2013–2017.Ontogenetic and seasonal variations in HSI models of mantis shrimp were also examined.Among the four models(non-optimized model,BRT informed HSI model,GAM informed HSI model,and both BRT and GAM informed HSI model),both BRT and GAM informed HSI model showed the best performance.Four environmental variables(bottom temperature,depth,distance offshore and sediment type)were selected in the HSI models for four groups(spring-juvenile,spring-adult,falljuvenile and fall-adult)of mantis shrimp.The distribution of habitat suitability showed similar patterns between juveniles and adults,but obvious seasonal variations were observed.This study suggests that the process of optimizing environmental variables in HSI models improves the performance of HSI models,and this optimization strategy could be extended to other marine organisms to enhance the understanding of the habitat suitability of target species.展开更多
Theranostics that integrates therapy and diagnosis in one system to achieve accurate cancer diagnosis and treatment has attracted tremendous interest,and has been recognized as a potential breakthrough in overcoming t...Theranostics that integrates therapy and diagnosis in one system to achieve accurate cancer diagnosis and treatment has attracted tremendous interest,and has been recognized as a potential breakthrough in overcoming the challenges of conventional oncotherapy.Nanoparticles are ideal candidates as carriers for theranostic agents,which is attributed to their extraordinary physicochemical properties,including nanoscale sizes,functional properties,prolonged blood circulation,active or passive tumor targeting,specific cellular uptake,and in some cases,excellent optical properties that ideally meet the needs of phototherapy and imaging at the same time.Overall,with the development of nanotechnology,theranostics has become a reality,and is now in the transition stage of"bench to bedside."In this review,we summarize recent progress on nanotechnology-based theranostics,i.e.,nanotheranostics,that has greatly assisted traditional therapies,and has provided therapeutic strategies emerging in recent decades,as well as"cocktail"theranostics mixing various treatment modalities.展开更多
The activation of methane on graphite surfaces with monovacancies and 5-8-5 vacancies have been investigated using density functional theory. Sixteen different initial adsorption configurations were investigated to id...The activation of methane on graphite surfaces with monovacancies and 5-8-5 vacancies have been investigated using density functional theory. Sixteen different initial adsorption configurations were investigated to identify the most favorable activation site.It is found that methane tends to be activated on the defective graphite surfaces,and the most stable configuration is that methane activation happened in the center hole of the monovacancy site,with a reaction energy of 1.13 eV.Electron transfer and weaker electrostatic potential of the vacancy region indicate that carbon atom of methane tends to fill the vacancy and makes the system more stable.展开更多
Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal...Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal variations in the fishery and biological characteristics of the population have been rarely evaluated and less well understood in this area. We studied the growth, spawning and feeding characteristics of C. myriaster on the basis of samples collected from October 2016 to April 2017 in the Yellow Sea and East China Sea. A total of 529 specimens were collected, with ages ranging from 1 to 6 years and total length ranging from 132 mm to 834 mm. The parameters of von Bertalanffy growth equation L∞ and k were 1 026 mm and 0.226 a^–1, respectively;the sex ratio was 88:0 (female: male) in the East China Sea and 2.67:1 in the South Yellow Sea;the development stage of ovary ranged from peri-nucleolus stage to secondary yolk globule stage, and the testis of two males was at midmeiotic stage;Crustacean was the major prey for conger of small length, and food source shift to fish with somatic growth. The results showed substantial differences from previous studies in Japan and Korean waters, as well as from China seas in the 1980s, suggesting potential spatiotemporal changes in the biological characteristics of C. myriaster. This study may improve current understanding of the fishery biology of C. myriaster in the Yellow Sea and East China Sea.展开更多
Resuscitation promoting factor E(RpfE)is one of the five Rpf-like proteins in Mycobacterium tuberculosis(M.tuberculosis).These Rpf-like proteins are secretory,which make them candidates for recognition by the host imm...Resuscitation promoting factor E(RpfE)is one of the five Rpf-like proteins in Mycobacterium tuberculosis(M.tuberculosis).These Rpf-like proteins are secretory,which make them candidates for recognition by the host immune system.In this study,the RpfE gene was amplified from M.tuberculosis,cloned into the expression vectors pDE22 and pPRO EXHT,and were expressed in Mycobacterium vaccae(M.vaccae)and Escherichia coli DH5α,respectively.Both recombinant RpfE proteins were purified by Ni-Sepharose affinity chromatography,and were given to C57BL/6 mice.The RpfE proteins elicited T cell proliferation,and stimulated the production of gamma interferon(IFN-γ),interleukin-10(IL-10)and IL-12.Our results indicated that the RpfE protein expressed in M.vaccae could more efficiently stimulate cellular immune response,making it a promising candidate as a subunit vaccine.展开更多
As one of the top four commercially important species in China,yellow croaker(Larimichthys polyactis)with two geographic subpopulations,has undergone profound changes during the last several decades.It is widely compr...As one of the top four commercially important species in China,yellow croaker(Larimichthys polyactis)with two geographic subpopulations,has undergone profound changes during the last several decades.It is widely comprehended that understanding its population dynamics is critically important for sustainable management of this valuable fishery in China.The only two existing population dynamics models assessed the population of yellow croaker using short time-series data,without considering geographical variations.In this study,Bayesian models with and without hierarchical subpopulation structure were developed to explore the spatial heterogeneity of the population dynamics of yellow croaker from 1968 to 2015.Alternative hypotheses were constructed to test potential temporal patterns in yellow croaker’s population dynamics.Substantial variations in population dynamics characteristics among space and time were found through this study.The population growth rate was revealed to increase since the late 1980s,and the catchability increased more than twice from 1981 to 2015.The East China Sea’s subpopulation witnesses faster growth,but suffers from higher fishing pressure than that in the Bohai Sea and Yellow Sea.The global population and two subpopulations all have high risks of overfishing and being overfished according to the MSY-based reference points in recent years.More conservative management strategies with subpopulation considerations are imperative for the fishery management of yellow croaker in China.The methodology developed in this study could also be applied to the stock assessment and fishery management of other species,especially for those species with large spatial heterogeneity data.展开更多
The existing study was taken to represent the current information in order to develop a mass-balanced ecosystem model within the resettled maritime boundary area of the Bay of Bengal(BoB),Bangladesh from July 2016 to ...The existing study was taken to represent the current information in order to develop a mass-balanced ecosystem model within the resettled maritime boundary area of the Bay of Bengal(BoB),Bangladesh from July 2016 to June 2017 through ECOPATH approach covering over 90 000 km2.A total of 19 functional groups were considered representing all trophic levels in the foodweb where estimated trophic interactions between the groups were varied from 1(primary producers and detritus)to 3.45(sharks).The ecotrophic efficiency(EE)of most of the consumers was greater than 0.80;symbolizing a largely exploited ecosystem and high energy transfer from lower to higher trophic levels.Moreover,the gross efficiency(0.001 8)and transfer efficiency(11.12%)of the whole system symbolizes the“Developing Systems”with somewhat maturity currently.Ecosystem’s overhead(64.6)and ascendancy(35.4)also designate the ecosystem’s stability.Thus,this study determines that the resettled maritime area of BoB reserves significant backup strength to face stress situations having capacity to rapid restoration to the original states.展开更多
In recent years,Konosirus punctatus has accounted for a large portion in catch composition and become important economic species in the South Yellow Sea.However,the distribution of K.punctatus early life stages is sti...In recent years,Konosirus punctatus has accounted for a large portion in catch composition and become important economic species in the South Yellow Sea.However,the distribution of K.punctatus early life stages is still poorly understood.In this study,generalized additive models with Tweedie distribution were used to analyze the relationships between K.punctatus ichthyoplankton and environmental factors(longitude and latitude,sea surface temperature(SST),sea surface salinity(SSS)and depth),and predict distribution K.punctatus spawning ground and nursing ground,based on samplings collected in 6 months during 2014–2017.The results showed that K.punctatus’spawning ground were mainly distributed in central and north study area(from 33.0°N to 37.0°N).By comparison,the nursing ground shifted southward,which were approximately located along central and south coast of study area(from 31.7°N to 35.5°N).The optimal models identified that suitable SST,SSS and depth for eggs were 19–26℃,25–30 and 9–23 m,respectively.The suitable SSS for larvae were 29–31.The K.punctatus spawning habit might have changed in the past decades,which was a response to increasing SST and fishing pressure.That needs to be proved in further study.The study provides references of conservation and exploitation for K.punctatus.展开更多
Feeding activities provide necessary nutrition and energy to support the reproduction and development of fish populations.The feeding ecology and dietary plasticity of fish are important factors determining their recr...Feeding activities provide necessary nutrition and energy to support the reproduction and development of fish populations.The feeding ecology and dietary plasticity of fish are important factors determining their recruitment and population dynamics.As a top predator,Japanese Spanish mackerel(Scomberomorus niphonius)supports one of the most valuable fisheries in China.In this study,the feeding ecology and diet composition of Japanese Spanish mackerel spawning groups were analysed based on samples collected from six spawning grounds along the eastern coastal waters of China during spring(March to May)in 2016 and 2017.Both stomach contents and stable isotope analysis were conducted.Stomach content analysis showed that spawning groups of Japanese Spanish mackerel mainly fed on fish,consuming more than 40 different prey species.Diets were significantly different among sampling locations.The most important prey species were Stolephorus in Fuzhou,Japanese anchovy Engraulis japonicus in Xiangshan,Euphausia pacifica in Lüsi,sand lance Ammodytes personatus in Qingdao and Weihai,and Leptochela gracilis in Laizhou Bay.Stable isotope analysis showed that the trophic level of Japanese Spanish mackerel was relatively high and generally increased with latitude from south to north.In the 1980 s,the diet of Japanese Spanish mackerel was dominated solely by Japanese anchovies in the eastern coastal waters of China.The results in the present study showed that the importance of Japanese anchovies declined considerably,and this fish was not the most dominant diet in most of the investigated waters.Both the spatial variations in diet composition and changes in the dominant diet over the long term indicated the high adaptability of Japanese Spanish mackerel to the environment.Combining the results of stomach analysis and stable isotope analysis from different tissues provided more comprehensive and accurate dietary information on Japanese Spanish mackerel.The study provides essential information about the feeding ecology of Japanese Spanish mackerel and will benefit the management of its populations in the future.展开更多
This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into t...This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into three categories:(1) direct indices, like the trophic level of species, influenced by stomach sample size directly;(2)indirect indices, like ecology efficiency(EE) of invertebrates, influenced by the multiple prey-predator relationships;and(3) systemic indices, like total system throughout(TST), describing the status of the whole ecosystem. The influences of different stomach sample sizes on these indices were evaluated. The results suggest that systemic indices of the ecosystem model were robust to stomach sample sizes, whereas specific indices related to species were indicated to be with low accuracy and precision when stomach samples were insufficient.The indices became more uncertain when the stomach sample sizes varied for more species. This study enhances the understanding of how the quality of diet composition data influences ecosystem modeling outputs. The results can also guide the design of stomach content analysis for developing ecosystem models.展开更多
Fixed-station sampling design was widely used in fishery-independent surveys because of its characteristics of convenient sampling station setting,but the non-probabilistic(fixed)nature made it more uncertainty of dra...Fixed-station sampling design was widely used in fishery-independent surveys because of its characteristics of convenient sampling station setting,but the non-probabilistic(fixed)nature made it more uncertainty of drawing inferences on population.The performance of fixed-station sampling design for multispecies survey has not been evaluated,and we are uncertain if the design could detect the temporal trends of different populations in multispecies fishery-independent survey.In this study,spatial distribution of abundance indices for three species with different spatial distribution patterns including small yellow croaker(Larimichthys polyactis),whitespotted conger(Conger myriaster)and Fang’s blenny(Enedrias fangi)were simulated using ordinary kriging interpolation as the“true”population distribution.The performance of fixed-station sampling design was compared with simple random sampling design by resampling the simulated“true”populations in this simulation study.The results showed that the fixed-station sampling design had the power to detect the seasonal trends of species abundance.The effectiveness of fixed-station sampling design were different in different species distribution patterns.When the species had even distribution,fixed-station sampling design could get high quality abundance data;when the distribution was uneven with heterogeneity or patchiness,fixed-station sampling design tended to underestimate or overestimate the abundance.Evidently,the estimates of abundance index based on the fixedstation sampling design must be calibrated cautiously while applying them for fisheries stock assessment and management.This study suggested that fixed-station sampling design could catch the temporal dynamics of population abundance,but the abundance estimates from the fixed-station sampling design could not be treated as the absolute estimates of populations.展开更多
基金Supported by the National Key R&D Program of China(No.2017YFE0104400)the National Natural Science Foundation of China(Nos.31772852,31802301)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0501-2)。
文摘A habitat model has been widely used to manage marine species and analyze relationship between species distribution and environmental factors.The predictive skill in habitat model depends on whether the models include appropriate explanatory variables.Due to limited habitat range,low density,and low detection rate,the number of zero catches could be very large even in favorable habitats.Excessive zeroes will increase the bias and uncertainty in estimation of habitat.Therefore,appropriate explanatory variables need to be chosen first to prevent underestimate or overestimate species abundance in habitat models.In addition,biotic variables such as prey data and spatial autocovariate(SAC)of target species are often ignored in species distribution models.Therefore,we evaluated the eff ects of input variables on the performance of generalized additive models(GAMs)under excessive zero catch(>70%).Five types of input variables were selected,i.e.,(1)abiotic variables,(2)abiotic and biotic variables,(3)abiotic variables and SAC,(4)abiotic,biotic variables and SAC,and(5)principal component analysis(PCA)based abiotic and biotic variables and SAC.Belanger’s croaker Johnius belangerii is one of the dominant demersal fish in Haizhou Bay,with a large number of zero catches,thus was used for the case study.Results show that the PCA-based GAM incorporated with abiotic and biotic variables and SAC was the most appropriate model to quantify the spatial distribution of the croaker.Biotic variables and SAC were important and should be incorporated as one of the drivers to predict species distribution.Our study suggests that the process of input variables is critical to habitat modelling,which could improve the performance of habitat models and enhance our understanding of the habitat suitability of target species.
基金The National Key R&D Program of China under contract No.2018YFD0900904the National Natural Science Foundation of China under contract Nos 31772852 and 31802301。
文摘Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.
文摘New coronavirus pneumonia spread rapidly all over the world in the first half of 2020, which is a new respiratory disease with strong infectiousness. At present, the epidemic situation in China has been effectively controlled, but the global epidemic situation remains grim, and the National Health Commission has instructed that the prevention and control of new coronavirus pneumonia should become normalized. As outposts for surveillance of public health events, hospitals are an important front in the fight against the epidemic. Therefore, it is very crucial to construct infection prevention and control system actively to contain the outbreak. This paper analyzes and summarizes the normal prevention and control management strategy of Infection Control Branch Management (hereinafter referred to as Hospital Infection-Control Dept) in a certain designated comprehensive third-grade hospital in Guangdong Province and transforms the prevention and control means in emergency state into measures for sustainable development, which also provides basis and reference for Hospital Infection-Control Dept of medical institutions to formulate prevention and control guidelines.
基金financially supported by the National Natural Science Foundation of China(21476145)the National 973 Program of Ministry of Sciences and Technologies of China(2011CB201202)
文摘The density functional theory was used to investigate the adsorption of CH_4 and H_2O on different rank coal surfaces.The coal rank is the dominant factor in affecting the adsorption capacity of coal.In order to better understand gas and water interaction with coal of different maturity,we developed fourteen coal models to represent the different rank coal.The interactions of CH_4 and H_2O with coal surfaces were studied and characterized by their adsorption energies,Mulliken charges and electrostatic potential surfaces.The results revealed that the interaction between coal and CH_4 was weak physical adsorption,and that the interaction between coal and H_2 O consisted of physical and chemical adsorption.Adsorption energy of coal–H_2O system was larger than that of coal–CH_4 on all rank coals,suggesting that the adsorption priority in the coal models is H_2 O > CH_4.Consequently,the injection of H_2 O into the different rank coal could effectively enhance the coal bed methane(CBM) recovery.
基金Supported by Key R&D Programs in Shandong China,No.2019GSF10822Jinan Science&Technology Bureau,No.201704125.
文摘BACKGROUND Single incision plus one port left-side approach(SILS+1/L)totally laparoscopic distal gastrectomy(TLDG)is an emerging technique for the treatment of gastric cancer.Reduced port laparoscopic gastrectomy has a number of potential advantages for patients compared with conventional laparoscopic gastrectomy:relieving postoperative pain,shortening hospital stay and offering a better cosmetic outcome.Nevertheless,there are no previous reports on the use of SILS+1/L TLDG with uncut Roux-en-Y(uncut R-Y)reconstruction.AIM To investigate the initial feasibility of SILS+1/L TLDG with uncut Roux-en-Y digestive tract reconstruction(uncut R-Y reconstruction)to treat distal gastric cancer.METHODS A total of 21 patients who underwent SILS+1/L TLDG with uncut R-Y reconstruction for gastric cancer were enrolled.All patients were treated at The Second Hospital of Shandong University.Reconstructions were performed intracorporeally with 60 mm endoscopic linear stapler and 45 mm no-knife stapler.The clinicopathological characteristics,surgical details,postoperative short-term outcomes,postoperative follow-up upper gastrointestinal radiography findings and endoscopy results were analyzed retrospectively.RESULTS All SILS+1/L operations were performed by SILS+1/L TLDG successfully.The patient population included 13 men and 8 women with a mean age of 48.2 years(ranged from 40 years to 70 years)and median body mass index of 22.8 kg/m^2.There were no conversions to open laparotomy,and no other port was placed.The mean operation time was 146 min(ranged 130-180 min),and the estimated mean blood loss was 54 mL(ranged 20-110 mL).The mean duration to flatus and discharge was 2.3(ranged 1-3.5)and 7.3(ranged 6-9)d,respectively.The mean number of retrieved lymph nodes was 42(ranged 30-47).Two patients experienced mild postoperative complications,including surgical site infection(wound at the navel incision)and mild postoperative pancreatic fistula(grade A).Follow-up upper gastrointestinal radiography and endoscopy were carried out at 3 mo postoperatively.No patients experienced moderate or severe food stasis,alkaline gastritis or bile reflux during the follow-up period.No recanalization of the biliopancreatic limb was found.CONCLUSION SILS+1/L TLDG with uncut R-Y reconstruction could be safely performed as a reduced port surgery.
基金The National Key R&D Program of China under contract No.2017YFE0104400the National Natural Science Foundation of China under contract No.31772852the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2018SDKJ0501-2。
文摘Habitat suitability index(HSI)models have been widely used to analyze the relationship between species abundance and environmental factors,and ultimately inform management of marine species.The response of species abundance to each environmental variable is different and habitat requirements may change over life history stages and seasons.Therefore,it is necessary to determine the optimal combination of environmental variables in HSI modelling.In this study,generalized additive models(GAMs)were used to determine which environmental variables to be included in the HSI models.Significant variables were retained and weighted in the HSI model according to their relative contribution(%)to the total deviation explained by the boosted regression tree(BRT).The HSI models were applied to evaluate the habitat suitability of mantis shrimp Oratosquilla oratoria in the Haizhou Bay and adjacent areas in 2011 and 2013–2017.Ontogenetic and seasonal variations in HSI models of mantis shrimp were also examined.Among the four models(non-optimized model,BRT informed HSI model,GAM informed HSI model,and both BRT and GAM informed HSI model),both BRT and GAM informed HSI model showed the best performance.Four environmental variables(bottom temperature,depth,distance offshore and sediment type)were selected in the HSI models for four groups(spring-juvenile,spring-adult,falljuvenile and fall-adult)of mantis shrimp.The distribution of habitat suitability showed similar patterns between juveniles and adults,but obvious seasonal variations were observed.This study suggests that the process of optimizing environmental variables in HSI models improves the performance of HSI models,and this optimization strategy could be extended to other marine organisms to enhance the understanding of the habitat suitability of target species.
基金supported by the National Natural Science Foundation of China(Grant Nos.22077038 and 21702070)the National Basic Research Plan of China(Grant No.2018YFA0208903)+2 种基金the Postdoctoral Research Foundation of China(Grant No.2017M612461)the National Undergraduate Program for Innovation and Entrepreneurship of China(Grant No.19YA06)the Shenzhen Science and Technology Project(Grant No.JCYJ20170818161I36779)。
文摘Theranostics that integrates therapy and diagnosis in one system to achieve accurate cancer diagnosis and treatment has attracted tremendous interest,and has been recognized as a potential breakthrough in overcoming the challenges of conventional oncotherapy.Nanoparticles are ideal candidates as carriers for theranostic agents,which is attributed to their extraordinary physicochemical properties,including nanoscale sizes,functional properties,prolonged blood circulation,active or passive tumor targeting,specific cellular uptake,and in some cases,excellent optical properties that ideally meet the needs of phototherapy and imaging at the same time.Overall,with the development of nanotechnology,theranostics has become a reality,and is now in the transition stage of"bench to bedside."In this review,we summarize recent progress on nanotechnology-based theranostics,i.e.,nanotheranostics,that has greatly assisted traditional therapies,and has provided therapeutic strategies emerging in recent decades,as well as"cocktail"theranostics mixing various treatment modalities.
基金supported by the National Basic Research Program of China(973Program)(2011CB201202)
文摘The activation of methane on graphite surfaces with monovacancies and 5-8-5 vacancies have been investigated using density functional theory. Sixteen different initial adsorption configurations were investigated to identify the most favorable activation site.It is found that methane tends to be activated on the defective graphite surfaces,and the most stable configuration is that methane activation happened in the center hole of the monovacancy site,with a reaction energy of 1.13 eV.Electron transfer and weaker electrostatic potential of the vacancy region indicate that carbon atom of methane tends to fill the vacancy and makes the system more stable.
基金The National Natural Science Foundation of China under contract No.31772852the Fundamental Research Funds for the Central Universities under contract No.201562030
文摘Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal variations in the fishery and biological characteristics of the population have been rarely evaluated and less well understood in this area. We studied the growth, spawning and feeding characteristics of C. myriaster on the basis of samples collected from October 2016 to April 2017 in the Yellow Sea and East China Sea. A total of 529 specimens were collected, with ages ranging from 1 to 6 years and total length ranging from 132 mm to 834 mm. The parameters of von Bertalanffy growth equation L∞ and k were 1 026 mm and 0.226 a^–1, respectively;the sex ratio was 88:0 (female: male) in the East China Sea and 2.67:1 in the South Yellow Sea;the development stage of ovary ranged from peri-nucleolus stage to secondary yolk globule stage, and the testis of two males was at midmeiotic stage;Crustacean was the major prey for conger of small length, and food source shift to fish with somatic growth. The results showed substantial differences from previous studies in Japan and Korean waters, as well as from China seas in the 1980s, suggesting potential spatiotemporal changes in the biological characteristics of C. myriaster. This study may improve current understanding of the fishery biology of C. myriaster in the Yellow Sea and East China Sea.
基金supported by National Natural Science Foundation of China (No.30470097,No.30500432)
文摘Resuscitation promoting factor E(RpfE)is one of the five Rpf-like proteins in Mycobacterium tuberculosis(M.tuberculosis).These Rpf-like proteins are secretory,which make them candidates for recognition by the host immune system.In this study,the RpfE gene was amplified from M.tuberculosis,cloned into the expression vectors pDE22 and pPRO EXHT,and were expressed in Mycobacterium vaccae(M.vaccae)and Escherichia coli DH5α,respectively.Both recombinant RpfE proteins were purified by Ni-Sepharose affinity chromatography,and were given to C57BL/6 mice.The RpfE proteins elicited T cell proliferation,and stimulated the production of gamma interferon(IFN-γ),interleukin-10(IL-10)and IL-12.Our results indicated that the RpfE protein expressed in M.vaccae could more efficiently stimulate cellular immune response,making it a promising candidate as a subunit vaccine.
基金Foundation item:The National Key R&D Program of China under contract No.2017YFE0104400the National Natural Science Foundation of China under contract No.31772852the Fundamental Research Funds for the Central Universities under contract Nos 201512002 and 201562030.
文摘As one of the top four commercially important species in China,yellow croaker(Larimichthys polyactis)with two geographic subpopulations,has undergone profound changes during the last several decades.It is widely comprehended that understanding its population dynamics is critically important for sustainable management of this valuable fishery in China.The only two existing population dynamics models assessed the population of yellow croaker using short time-series data,without considering geographical variations.In this study,Bayesian models with and without hierarchical subpopulation structure were developed to explore the spatial heterogeneity of the population dynamics of yellow croaker from 1968 to 2015.Alternative hypotheses were constructed to test potential temporal patterns in yellow croaker’s population dynamics.Substantial variations in population dynamics characteristics among space and time were found through this study.The population growth rate was revealed to increase since the late 1980s,and the catchability increased more than twice from 1981 to 2015.The East China Sea’s subpopulation witnesses faster growth,but suffers from higher fishing pressure than that in the Bohai Sea and Yellow Sea.The global population and two subpopulations all have high risks of overfishing and being overfished according to the MSY-based reference points in recent years.More conservative management strategies with subpopulation considerations are imperative for the fishery management of yellow croaker in China.The methodology developed in this study could also be applied to the stock assessment and fishery management of other species,especially for those species with large spatial heterogeneity data.
基金The Fundamental Research Funds for the Central Universities of China under contract No.201562030
文摘The existing study was taken to represent the current information in order to develop a mass-balanced ecosystem model within the resettled maritime boundary area of the Bay of Bengal(BoB),Bangladesh from July 2016 to June 2017 through ECOPATH approach covering over 90 000 km2.A total of 19 functional groups were considered representing all trophic levels in the foodweb where estimated trophic interactions between the groups were varied from 1(primary producers and detritus)to 3.45(sharks).The ecotrophic efficiency(EE)of most of the consumers was greater than 0.80;symbolizing a largely exploited ecosystem and high energy transfer from lower to higher trophic levels.Moreover,the gross efficiency(0.001 8)and transfer efficiency(11.12%)of the whole system symbolizes the“Developing Systems”with somewhat maturity currently.Ecosystem’s overhead(64.6)and ascendancy(35.4)also designate the ecosystem’s stability.Thus,this study determines that the resettled maritime area of BoB reserves significant backup strength to face stress situations having capacity to rapid restoration to the original states.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.201305030the National Natural Science Foundation of China under contract No.41930535。
文摘In recent years,Konosirus punctatus has accounted for a large portion in catch composition and become important economic species in the South Yellow Sea.However,the distribution of K.punctatus early life stages is still poorly understood.In this study,generalized additive models with Tweedie distribution were used to analyze the relationships between K.punctatus ichthyoplankton and environmental factors(longitude and latitude,sea surface temperature(SST),sea surface salinity(SSS)and depth),and predict distribution K.punctatus spawning ground and nursing ground,based on samplings collected in 6 months during 2014–2017.The results showed that K.punctatus’spawning ground were mainly distributed in central and north study area(from 33.0°N to 37.0°N).By comparison,the nursing ground shifted southward,which were approximately located along central and south coast of study area(from 31.7°N to 35.5°N).The optimal models identified that suitable SST,SSS and depth for eggs were 19–26℃,25–30 and 9–23 m,respectively.The suitable SSS for larvae were 29–31.The K.punctatus spawning habit might have changed in the past decades,which was a response to increasing SST and fishing pressure.That needs to be proved in further study.The study provides references of conservation and exploitation for K.punctatus.
基金The Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2018SDKJ0501-2the National Key R&D Program of China under contract No.2017YEE0104400the National Natural Science Foundation of China under contract Nos 31772852 and 31802301。
文摘Feeding activities provide necessary nutrition and energy to support the reproduction and development of fish populations.The feeding ecology and dietary plasticity of fish are important factors determining their recruitment and population dynamics.As a top predator,Japanese Spanish mackerel(Scomberomorus niphonius)supports one of the most valuable fisheries in China.In this study,the feeding ecology and diet composition of Japanese Spanish mackerel spawning groups were analysed based on samples collected from six spawning grounds along the eastern coastal waters of China during spring(March to May)in 2016 and 2017.Both stomach contents and stable isotope analysis were conducted.Stomach content analysis showed that spawning groups of Japanese Spanish mackerel mainly fed on fish,consuming more than 40 different prey species.Diets were significantly different among sampling locations.The most important prey species were Stolephorus in Fuzhou,Japanese anchovy Engraulis japonicus in Xiangshan,Euphausia pacifica in Lüsi,sand lance Ammodytes personatus in Qingdao and Weihai,and Leptochela gracilis in Laizhou Bay.Stable isotope analysis showed that the trophic level of Japanese Spanish mackerel was relatively high and generally increased with latitude from south to north.In the 1980 s,the diet of Japanese Spanish mackerel was dominated solely by Japanese anchovies in the eastern coastal waters of China.The results in the present study showed that the importance of Japanese anchovies declined considerably,and this fish was not the most dominant diet in most of the investigated waters.Both the spatial variations in diet composition and changes in the dominant diet over the long term indicated the high adaptability of Japanese Spanish mackerel to the environment.Combining the results of stomach analysis and stable isotope analysis from different tissues provided more comprehensive and accurate dietary information on Japanese Spanish mackerel.The study provides essential information about the feeding ecology of Japanese Spanish mackerel and will benefit the management of its populations in the future.
基金The National Natural Science Foundation of China under contract No.31772852the Fundamental Research Funds for the Central Universities under contract No.201612004。
文摘This study used Ecopath model of the Jiaozhou Bay as an example to evaluate the effect of stomach sample size of three fish species on the projection of this model. The derived ecosystem indices were classified into three categories:(1) direct indices, like the trophic level of species, influenced by stomach sample size directly;(2)indirect indices, like ecology efficiency(EE) of invertebrates, influenced by the multiple prey-predator relationships;and(3) systemic indices, like total system throughout(TST), describing the status of the whole ecosystem. The influences of different stomach sample sizes on these indices were evaluated. The results suggest that systemic indices of the ecosystem model were robust to stomach sample sizes, whereas specific indices related to species were indicated to be with low accuracy and precision when stomach samples were insufficient.The indices became more uncertain when the stomach sample sizes varied for more species. This study enhances the understanding of how the quality of diet composition data influences ecosystem modeling outputs. The results can also guide the design of stomach content analysis for developing ecosystem models.
基金The Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2018SDKJ0501-2the National Key Research and Development Program of China under contract No.2019YFD0901304。
文摘Fixed-station sampling design was widely used in fishery-independent surveys because of its characteristics of convenient sampling station setting,but the non-probabilistic(fixed)nature made it more uncertainty of drawing inferences on population.The performance of fixed-station sampling design for multispecies survey has not been evaluated,and we are uncertain if the design could detect the temporal trends of different populations in multispecies fishery-independent survey.In this study,spatial distribution of abundance indices for three species with different spatial distribution patterns including small yellow croaker(Larimichthys polyactis),whitespotted conger(Conger myriaster)and Fang’s blenny(Enedrias fangi)were simulated using ordinary kriging interpolation as the“true”population distribution.The performance of fixed-station sampling design was compared with simple random sampling design by resampling the simulated“true”populations in this simulation study.The results showed that the fixed-station sampling design had the power to detect the seasonal trends of species abundance.The effectiveness of fixed-station sampling design were different in different species distribution patterns.When the species had even distribution,fixed-station sampling design could get high quality abundance data;when the distribution was uneven with heterogeneity or patchiness,fixed-station sampling design tended to underestimate or overestimate the abundance.Evidently,the estimates of abundance index based on the fixedstation sampling design must be calibrated cautiously while applying them for fisheries stock assessment and management.This study suggested that fixed-station sampling design could catch the temporal dynamics of population abundance,but the abundance estimates from the fixed-station sampling design could not be treated as the absolute estimates of populations.