The impact of earlier flood recession on metacommunity diversity of wintering waterbirds at shallow lakes in the middle and lower Yangtze River floodplain

The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.

Flexible nest site selection of the endangered Oriental Storks(Ciconia boyciana):Trade-off from adaptive strategies

Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selection can provide insights into how species adapt to changes in their habitat and has important conservation implications.In this study,we used microhabitat variables and multi-scale data with a field survey of nest occurrence to determine nest site selection patterns and adaptive strategies of the breeding Oriental Storks(Ciconia boyciana)in different nest areas.Results demonstrate that the nest site microhabitat characteristics of the breeding Oriental Storks significantly differed among the three nesting areas,and nest height was higher in the middle and lower Yangtze River floodplain than in the Northeast China and Bohai Bay nest areas.The food resources and intensity of human disturbance had the greatest effects on the nest site selection of the breeding Oriental Storks.The intensity of human disturbance was positively correlated with the nest height of the breeding Oriental Storks in Bohai Bay and the middle and lower Yangtze River floodplain;however,nest height decreased with the abundance of food resources in the Northeast China nest area.Our findings indicate that the nest site selection patterns of Oriental Storks showed flexible adaptive strategies.In safer environments,nests were lower and closer to food resources,which allows parent storks to invest more in the nestlings.However,in areas where human activity was intense,nests were higher to ensure the safety of their offspring.Some measures that could be taken to improve the breeding habitat of Oriental Storks include increasing the percentage of wetland areas in nesting areas to enhance food resources availability and setting artificial nests at suitable heights in potential nesting grounds to encourage nesting.Finally,the establishment of soft barriers around the nesting areas could increase the safety of nests.

ABA-mediated regulation of leaf and root hydraulic conductance in tomato grown at elevated CO2 is associated with altered gene expression of aquaporins

Elevated CO_(2)concentration in the air(e[CO_(2)])decreases stomatal density(SD)and stomatal conductance(gs)where abscisic acid(ABA)may play a role,yet the underlying mechanism remains largely elusive.We investigated the effects of e[CO_(2)](800 ppm)on leaf gas exchange and water relations of two tomato(Solanum lycopersicum)genotypes,Ailsa Craig(WT)and its ABA-deficient mutant(flacca).Compared to plants grown at ambient CO_(2)(400 ppm),e[CO_(2)]stimulated photosynthetic rate in both genotypes,while depressed the gs only in WT.SD showed a similar response to e[CO_(2)]as gs,although the change was not significant.e[CO_(2)]increased leaf and xylem ABA concentrations and xylem sap pH,where the increases were larger in WT than in flacca.Although leaf water potential was unaffected by CO_(2)growth environment,e[CO_(2)]lowered osmotic potential,hence tended to increase turgor pressure particularly for WT.e[CO_(2)]reduced hydraulic conductance of leaf and root in WT but not in flacca,which was associated with downregulation of gene expression of aquaporins.It is concluded that ABA-mediated regulation of gs,SD,and gene expression of aquaporins coordinates the whole-plant hydraulics of tomato grown at different CO_(2)environments.

双特异性抗体构建在肿瘤临床治疗中的应用

双特异性抗体(Bispecific antibody,BsAb)是具有两个不同抗原结合位点的抗体,可分为含Fc段和不含Fc段的BsAb,不同结构的BsAb具有不同的特点和应用领域。相比于传统的单克隆抗体,BsAb的灵敏度和特异性更高。更重要的是,BsAb具有募集免疫细胞、双重阻断信号通路等功能,在免疫诊断和治疗中扮演重要角色。随着全球环境的恶化以及人们生活习惯的不规律,肿瘤的发病率越来越高,成为仅次于心脑血管疾病的全球第二大致死疾病,全球每年有1200万新发癌症病例。肿瘤的治疗手段包括手术切除、放化疗和靶向治疗等。肿瘤免疫疗法是近几年新兴的治疗方法,其通过激发自身免疫系统的能力来清除肿瘤细胞。传统的单抗药物虽在肿瘤靶向治疗和免疫治疗中取得了一定的疗效,但肿瘤具有高度的异质性和可塑性,常常引发肿瘤耐药性的出现。双特异性抗体能够同时靶向多个靶点,目前已用于肿瘤的临床治疗,并取得了一定的治疗效果。文中就双特异性抗体在肿瘤临床治疗中的研究进展和应用作一综述。

Highly anisotropic thermal conductivity of few-layer CrOCl for efficient heat dissipation in graphene device

With the packing density growing continuously in integrated electronic devices,sufficient heat dissipation becomes a serious challenge.Recently,dielectric materials with high thermal conductivity have brought insight into effective dissipation of waste heat in electronic devices to prevent them from overheating and guarantee the performance stability.Layered CrOCl,an antiferromagnetic insulator with low-symmetry crystal structure and atomic level flatness,might be a promising solution to the thermal challenge.Herein,we have systematically studied the thermal transport of suspended few-layer CrOCl flakes by microRaman thermometry.The CrOCl flakes exhibit high thermal conductivities along zigzag direction,from~392±33 to~1,017±46 W·m^(−1)·K^(−1) with flake thickness from 2 to 50 nm.Besides,pronounced thickness-dependent thermal conductivity ratio(/from~2.8±0.24 to~4.3±0.25)has been observed in the CrOCl flakes,attributed to the discrepancy of phonon dispersion and phonon surface scattering.As a demonstration to the heat sink application of layered CrOCl,we then investigate the energy dissipation in graphene devices on CrOCl,SiO_(2) and hexagonal boron nitride(h-BN)substrates,respectively.The graphene device temperature rise on CrOCl is only 15.4%of that on SiO_(2) and 30%on h-BN upon the same electric power density,indicating the efficient heat dissipation of graphene device on CrOCl.Our study provides new insights into two-dimentional(2D)dielectric material with high thermal conductivity and strong anisotropy for the application of thermal management in electronic devices.

Stimuli-responsive cyclometalated platinum complex bearing bent molecular geometry for highly efficient solution-processable OLEDs

Smart materials,such as stimuli-responsive luminescence,have attracted much attentions due to their potential application in semiconductor filed.In this context,platinum complexes of(dfppy-DC)Pt(acac) and(dfppy-O-DC)Pt(acac) were prepared and characterized,in which(2-(4',6'-difluorophenyl)pyridinato-N,C2')(2,4-pentanedionato-0,0)Pt(Ⅱ) was used as the planar emission core and 9-(4-(phenylsulfonyl)phenyl)-9 H-carbazole(DC) was regard as the bent pendent.Both platinum complexes showed bright emission in solution and solid state,concomitant with charming external-stimuli-responsive emission under mechanical grinding,organic solvent vapors and pressure.The change emission color spanned from yellow to near-infrared region.Using the platinum complexes as the dopant,solution processable organic light-emitting diodes(OLEDs) were fabricated and a maximum external quantum efficiency of ~18% was achieved,which is the highest value among the reported solution-processable OLEDs based on externalstimuli-responsive luminescence.This research demonstrated that platinum complex can show promising stimuli responsive emission via ingenious molecular design,indicating a novel way for developing the smart materials in semiconductor filed.

Organic solar cells based on small molecule donor and polymer acceptor

Small molecule donor/polymer acceptor(SD/PA)-type organic solar cells(OSCs)have attracted widespread attention in recent years due to the continuing power conversion efficiency(PCE)growth,near 10%,and the excellent thermal stability for the practical applications.However,the development of SD/PA-type OSCs lags far behind that of polymer donor/small molecule acceptor(PD/SA)-type OSCs,which are also based on the combination of small molecule and polymer,with the PCEs exceeding 18%.The reasons accounting for this great gap are well worth exploring.In this review,we have analyzed the key factors affecting the photovoltaic performances of SD/PA-type OSCs,systematically summarized the research progress of SD/PA type OSCs in recent years,and put forward our own views on the future development of SD/PA type OSCs.