As a simplified model of artificial reefs, a series of plate models punched with square or circular openings are designed to investigate the effects of openings on the hydrodynamic characteristics of artificial reefs....As a simplified model of artificial reefs, a series of plate models punched with square or circular openings are designed to investigate the effects of openings on the hydrodynamic characteristics of artificial reefs. The models are grouped by various opening numbers and opening-area ratios. They are physically tested in a water flume or used in the numerical simulation to obtain the drag force in the uniform flow with different speeds. The simulation results are found in good agreement with the experimental measurements. By the non-dimensional analysis, the drag coefficient specified to each model is achieved and the effects of openings are examined. It is found that the key factor affecting the drag coefficient is the open-area ratio. Generally, the drag coefficient is a linear function of the open area ratio with a minus slope. The empirical formulae for the square and circular openings respectively are deduced by means of the multiple regression analysis based on the measured and numerical data. They will be good references for the design of new artificial reefs. As a result of numerical simulation, the vorticity contours and pressure distribution are also presented in this work to better understand the hydrodynamic characteristics of different models.展开更多
The construction of artificial reefs has unparallelly developed for a few decades in China.Artificial reefs can be used to manage and conserve commercially exploited fish and crustacea.However,their suitability as eco...The construction of artificial reefs has unparallelly developed for a few decades in China.Artificial reefs can be used to manage and conserve commercially exploited fish and crustacea.However,their suitability as ecological niche is poorly characterized.Therefore,in this study,we detected the seasonal variation of community biodiversity and the corresponding driving environmental factors.We also explored the relationships between dominant species and environmental factors to identify appropriate ecological niche areas.Different statistical analysis methods were used to assess species distribution within an artificial reef area in Xixiakou during nine sampling events in four seasons between 2017 and 2018.Non-metric multidimensional scaling(NMDS)and cluster analysis results indicated that the components of community can be divided into two clusters.Complexity of community,which is exhibited by species number,biodiversity,and catch per unit effort(CPUE),was significantly higher in summer than in other seasons.Generalized additive model(GAMs)results revealed the significant effects of temperature and chlorophyll a on the community structure.Sebastes schlegelii,Hexagrammos otakii,Conger myriaster and Charybdis japonica were the dominant species in four seasons.GAMs results indicated that temperature,dissolved oxygen(DO),pH and chlorophyll a affect the CPUE of dominant species significantly.The distinct suitable ecological niche for each dominant species was found in this study.For example,Charybdis japonica preferred to live in the area with 20.7–22.1℃,dissolved oxygen 7.07–7.15 mg L−1 and salinity 31.8–31.9.The results of this study are beneficial to resource conservation and fishery management.展开更多
Background Dry eye is a multifactorial disease of the tears and the ocular surface.This study aimed to investigate the clinical efficacy of a non-steroidal anti-inflammatory drug,pranoprofen,in the treatment of dry ey...Background Dry eye is a multifactorial disease of the tears and the ocular surface.This study aimed to investigate the clinical efficacy of a non-steroidal anti-inflammatory drug,pranoprofen,in the treatment of dry eye.Methods It is a prospective,multi-center,randomized,controlled,parallel group study.One hundred and fifteen patients with mild to moderate dry eye disease （55-60 in each treatment group） participated in this multi-center study.Patients were randomly administered with eyedrops containing 0.1％ pranoprofen （PRA） plus 0.1％ sodium hyaluronate （SH） or SH only,three times daily for 28 days,followed by a 1-week after treatment observation.Dry eye symptom score （DESS）,fluorescein corneal staining （FLCS）,tear break-up time （TBUT）,and Shirmer 1 tear test （ST1,without anesthesia） were evaluated or conducted before treatment and at each study visit.Conjunctival impression cytology was taken from the patients treated with PRA plus SH before and after treatment and real-time polymerase chain reaction （RT-PCR） was performed to detect the changes of human leukocyte antigen DR （HLA-DR） and intercellular adhesion molecule 1 （ICAM-1）.Results Patients treated with PRA plus SH showed gradual improvements of DESS,FLCS,and TBUT.Between-group comparisons of FLCS and TBUT have statistically significant differences from day 14.Good tolerance with no severe adverse events was found in both groups.Patients treated with PRA plus SH had a reduced expression level of HLA-DR and were statistically different after 28 days of therapy.Conclusions The application of PRA at a dose of 0.1％ was well tolerated and benefited to the patients with mild to moderate dry eye disease.The underlying mechanism of its efficacy may be associated with the reduction of inflammatory factors of conjunctival epithelial cells.展开更多
基金supported by Shandong Provincial Oceanic and Fishery Department (Ecological Simulation Test of the Offshore Area in Shandong Peninsula)the Primary Research and Development Program of Shandong Province (Nos. 2016CYJS04A01 and 2017CXGC0107)
文摘As a simplified model of artificial reefs, a series of plate models punched with square or circular openings are designed to investigate the effects of openings on the hydrodynamic characteristics of artificial reefs. The models are grouped by various opening numbers and opening-area ratios. They are physically tested in a water flume or used in the numerical simulation to obtain the drag force in the uniform flow with different speeds. The simulation results are found in good agreement with the experimental measurements. By the non-dimensional analysis, the drag coefficient specified to each model is achieved and the effects of openings are examined. It is found that the key factor affecting the drag coefficient is the open-area ratio. Generally, the drag coefficient is a linear function of the open area ratio with a minus slope. The empirical formulae for the square and circular openings respectively are deduced by means of the multiple regression analysis based on the measured and numerical data. They will be good references for the design of new artificial reefs. As a result of numerical simulation, the vorticity contours and pressure distribution are also presented in this work to better understand the hydrodynamic characteristics of different models.
基金the Project of Marine and Fishery Technology Innovation of Shandong(No.2017 HYCX007).
文摘The construction of artificial reefs has unparallelly developed for a few decades in China.Artificial reefs can be used to manage and conserve commercially exploited fish and crustacea.However,their suitability as ecological niche is poorly characterized.Therefore,in this study,we detected the seasonal variation of community biodiversity and the corresponding driving environmental factors.We also explored the relationships between dominant species and environmental factors to identify appropriate ecological niche areas.Different statistical analysis methods were used to assess species distribution within an artificial reef area in Xixiakou during nine sampling events in four seasons between 2017 and 2018.Non-metric multidimensional scaling(NMDS)and cluster analysis results indicated that the components of community can be divided into two clusters.Complexity of community,which is exhibited by species number,biodiversity,and catch per unit effort(CPUE),was significantly higher in summer than in other seasons.Generalized additive model(GAMs)results revealed the significant effects of temperature and chlorophyll a on the community structure.Sebastes schlegelii,Hexagrammos otakii,Conger myriaster and Charybdis japonica were the dominant species in four seasons.GAMs results indicated that temperature,dissolved oxygen(DO),pH and chlorophyll a affect the CPUE of dominant species significantly.The distinct suitable ecological niche for each dominant species was found in this study.For example,Charybdis japonica preferred to live in the area with 20.7–22.1℃,dissolved oxygen 7.07–7.15 mg L−1 and salinity 31.8–31.9.The results of this study are beneficial to resource conservation and fishery management.
文摘Background Dry eye is a multifactorial disease of the tears and the ocular surface.This study aimed to investigate the clinical efficacy of a non-steroidal anti-inflammatory drug,pranoprofen,in the treatment of dry eye.Methods It is a prospective,multi-center,randomized,controlled,parallel group study.One hundred and fifteen patients with mild to moderate dry eye disease （55-60 in each treatment group） participated in this multi-center study.Patients were randomly administered with eyedrops containing 0.1％ pranoprofen （PRA） plus 0.1％ sodium hyaluronate （SH） or SH only,three times daily for 28 days,followed by a 1-week after treatment observation.Dry eye symptom score （DESS）,fluorescein corneal staining （FLCS）,tear break-up time （TBUT）,and Shirmer 1 tear test （ST1,without anesthesia） were evaluated or conducted before treatment and at each study visit.Conjunctival impression cytology was taken from the patients treated with PRA plus SH before and after treatment and real-time polymerase chain reaction （RT-PCR） was performed to detect the changes of human leukocyte antigen DR （HLA-DR） and intercellular adhesion molecule 1 （ICAM-1）.Results Patients treated with PRA plus SH showed gradual improvements of DESS,FLCS,and TBUT.Between-group comparisons of FLCS and TBUT have statistically significant differences from day 14.Good tolerance with no severe adverse events was found in both groups.Patients treated with PRA plus SH had a reduced expression level of HLA-DR and were statistically different after 28 days of therapy.Conclusions The application of PRA at a dose of 0.1％ was well tolerated and benefited to the patients with mild to moderate dry eye disease.The underlying mechanism of its efficacy may be associated with the reduction of inflammatory factors of conjunctival epithelial cells.
