Species interactions are often context-dependent and complex, such as the grasshopper community and phytoecommunity. The adaption of grasshopper abundance and plant community were determined by topographical heterogeneity. However, it remains vague about how vegetation community, such as coverage, abundance and height, influence the spatial distribution pattern of grasshopper abundance at the altitude gradient. The geostatistical methods were used in natural grassland of the upper reaches of Heihe River to quantify the relationship of spatial correlation. A 5-years investigation shown that 3149 of grasshoppers was collected，belonging to 3 families, 10 genera, and 13 species. The semivariable function of grasshopper abundance and vegetation community followed a nonlinear model. Meanwhile, horizontal distribution of two communities was a clear flaky and plaque distribution pattern, especially at the altitude gradient. The abundance of grasshoppers is opposite to the height and coverage of vegetation and the overall follow ability of coverage, while the local following is consistent. Such as grasshopper abundance, the above 2750m sample with the opposite trend, the following areas were consistent. The grasshoppers exhibited the varieties on vegetation characters among all directions. On the different habits, the spatial distribution formed uniform trends; meanwhile, on the same, the trends diversified with altitude gradient, formed embedded striped patches structure.

In recent years, with the frequencies and intensities was increasing in environmental issues, much more attentions were focus on sandstorm in the fields of natural science and social science research. The geostationary satellite imagery can continuously observe the surface of the earth in a short period of time, and has a good monitoring advantage for the sand- dust, which has a fast-moving target. Based on the geostationary meteorological satellite data of Himawari-8(H8) at 4:00 on May 3, 2017, the results of remote sensing retrieval of sand-dust intensity are compared by using a variety of exist sand- dust identification models. The results show that the multi-channel threshold method has the best effect on sand-dust identification, the reflected radiation dust index method is the second, and the infrared split window channel difference method and the infrared split window channel ratio method have the worst identification effect. Single channel threshold method, infrared multi-channel threshold method, infrared split window channel difference method and infrared split window channel ratio method have poor distinction between cloud layer and sand dust, multi-channel threshold method and reflected radiation dust index method are poor distinguished between low temperature zone and the sand-dust.

Stellera chamaejasme L. is one of the dominant poisonous plant species and has caused considerable damage to the stability of grassland ecosystems and changed the structure and function of the grassland community, leading to grassland degeneration. To examine the response of morphological features of S. chamaejasme L. populations to environmental variations, leaf and stem traits were investigated in alpine grassland along the northern slope of the Qilian Mountains in northwestern China. Additionally, the relationships between stem length and stem number and between stem length and leaf number were also determined. The environmental gradients included south-facing and north-facing slopes. The results showed that the S. chamaejasme L. population had greater leaf area, leaf number, stem number and stem length on north-facing slopes than those in the population on south-facing slopes. Significant allometric relationships were found between leaf number and stem length and between stem number and stem length. The two standardized major axis regression (SMA) slopes deviated significantly from 1, with the variation of the environmental gradients. The results showed that the two characters of the plant in SMA slopes were both steeper on the south-facing slopes than those on the north-facing slopes. The definition excluded that at a given stem length, ratios of stem number to stem length and leaf number to stem length were larger on south-facing slopes ecologically than those on north-facing slopes. These results demonstrated that S. chamaejasme L. responded to the slope aspect variations via changing leaf and stem architecture, most likely due to the more significant heat exchange of leaves and greater transporting requirements of stems on south-facing slopes than those on north-facing slopes.

目的 探讨新型抗氧化剂依达拉奉(edaravone,EDA)拮抗阿霉素(doxorubicin,DOX)诱导的H9C2心肌细胞损伤中的自噬机制.方法 H9C2心肌细胞加EDA和不同浓度DOX共同孵育后,MTT法检测细胞存活率并用试剂盒测定过氧化物岐化酶(SOD)活性和氧化代谢产物丙二醛(MDA)水平,DAPI染色法观察细胞凋亡情况,Western blot测定自噬相关蛋白LC3B表达水平.结果 在实验设置细胞评价体系下,浓度为1μg/ml的EDA可以显著提高DOX作用下H9C2心肌的存活率,同时能显著降低DOX(浓度为1uμmol/L)引起细胞中MDA水平(P ＜0.05,P＜0.01)的升高,且使DOX诱导的SOD活性的降低得到显著提升(P＜0.05),上述差异有统计学意义.DAPI染色结果显示EDA能够减少DOX导致的心肌细胞凋亡,并显著抑制DOX诱导的自噬相关蛋白LC3B的增加,差异有统计学意义(P ＜0.05,P＜0.01).结论 DOX能引起H9C2细胞产生氧化应激,并诱导细胞自噬进而使细胞凋亡.而EDA对DOX诱导的心肌细胞凋亡具有保护作用,这种作用可能是通过调节自噬并降低细胞内氧化应激损伤而保护的心肌细胞.

目的:筛选大鼠体内碱性彗星试验中阳性药环磷酰胺(CP)和甲基磺酸乙酯(EMS)的给药周期.方法:将SD大鼠随机分为空白对照组、CP组(40 mg/kg,腹腔注射)和EMS组(100 mg/kg,灌胃),每组9只,每24 h给药1次,连续给药4次.分别于第2、3、4次给药后3 h(即首次给药后27、51、75 h)各组随机选取3只大鼠,处死并收集肝和胃样本,经过制备单细胞悬液、制片、裂解、解链、电泳及染色后,使用Comet AssayⅣ彗星试验数据分析系统进行分析,以彗星尾部DNA百分比(Tail DNA％)、尾长(TL)和尾矩(TM)为评价指标,筛选最佳给药周期.结果:空白对照组大鼠3个检测时间点肝和胃的Tail DNA％、TL、TM差异均无统计学意义(P>0.05),表明彗星试验体系比较稳定.与空白对照组比较,CP组和EMS组大鼠3个检测时间点肝和胃的Tail DNA％、TL(27 h的胃除外)、TM均明显升高(P<0.05).其中,CP组大鼠3个检测时间点间肝的Tail DNA％、TL、TM差异均无统计学意义(P>0.05),胃的Tail DNA％、TL均在给药51 h时最大,TM随给药时间的延长而升高;EMS组大鼠肝的Tail DNA％、胃和肝的TM均随给药时间的延长而升高.EMS组大鼠胃的Tail DNA％、肝和胃的TL均在给药51 h时最大.结论:在进行体内碱性彗星试验时,建议CP和EMS的给药周期是每24 h给药1次,连续给药3次.

Objective:To study the influence of PTD-CHMP1A (protein transduction domain-chromatin modifying protein 1A) fusion proteins on proliferation,migration and invasion of renal cell carcinoma (RCC) cells in vitro and the growth of transplanted rumor in vivo.Methods:RCC A498 and 786-0 cells were treated with PTD-CHMP1A (1,5,and 20 μg/ml),CHMP1A (5 μg/ml) and PBS respectively.The effect of PTD-CHMP1A on the proliferation ofA498 cells was detected by MTT assay.The effect of PTD-CHMP1A on the migration ofA498 cells was detected by scratch assay.The effect of PTD-CHMP 1A on the invasion ability ofA498 and 786-0 cells was detected by Transwell invasion assay.Finally,the transplanted tumor models were constructed by injecting 5 × 105 A498 cells into nude mice,and the effect of 20 μg PTD-CHMP1A on tumor growth was observed.Results:Compared with CHMP1A and PBS groups,PTD-CHMP1A fusion proteins (1,5,and 20 μg/ml) showed a significantly restrained effect on the proliferation ofA498 tumor cells,which was in dose-dependent and time-dependent manners.5 μg/ml of PTD-CHMP1A fusion proteins could effectively inhibit the migration ofA498 cells (P＜0.01 compared with CHMP1A group),and the invasion ofA498 and 786-0 cells (compared with Chmp1A group,P＜ 0.05),besides,PTD-CHMP1A inhibited the invasion ofA498 cells in a dose-dependent manner.Furthermore,PTD-CHMP1A could also observably inhibit tumor growth in vivo.Conclusion:PTD-CHMP1A fusion proteins effectively inhibited the proliferation,migration and invasion of RCC cells and the growth of transplanted tumor.

Species interactions are often context-dependent and complex, such as the grasshopper community and phytoecommunity. The adoption of grasshopper abundance and vegetation community was determined by topographical heterogeneity. However, it remains vague about how vegetation community, such as coverage abundance and height, influence the spatial distribution pattern of grasshopper abundance at the altitude gradient. Using Geostatistical methods in natural grassland of the upper reaches of Heihe River to quantitatively study the relationship of spatial correlation. A 3 years investigation was shown that 3149 grasshoppers were collected, belonging to 3 families, 10 genera, and 13 species. The semivariable function of grasshopper abundance and vegetation community followed a nonlinear model. Meanwhile, horizontal distribution of two communities was a clear flaky and plaque distribution pattern, especially at the altitude gradient. The abundance of grasshoppers is opposite to the height and coverage of vegetation and the overall followability of coverage, while the local following is consistent. Such as grasshopper abundance, the above 2750m sample with the opposite trend, the following areas are consistent. Finally, grasshoppers have the different choice on different vegetation characteristics in different directions, formed of specific trend characteristics; and the spatial distribution trend is different even with the same community indicators, formed of embedded striped patches structure.

Lower limb rehabilitation robot has showed great potential in improving human walking ability. The purpose of this study is to compare the differences in human muscle activity of the lower limb while walking with different patterns. In order to meet the individual needs of different kinds of patients with lower limb dysfunction, an end-effector hybrid rehabilitation robot concept with multi-degree freedom is designed based on human factor. Human-robot coupling model is established in the AnyBody Modeling System, inverse dynamic analysis of movement and muscle activity of the human body is simulated. Effects of gait trajectory and the degree of freedom simplification of rehabilitation robot on human physiological parameters are discussed. The results indicate that foot trajectory, ankle posture, and mobility of robot is of vital importance and can be realized according to specific human factor in rehabilitation robot design and trajectory planning. Analysis methods and results are meaningful for lower limb rehabilitation robot design and rehabilitation evaluation.

In order to overcome the drawbacks of traditional gait training methods, gait rehabilitation robotized systems have been developed to provide a consistent, labor-saving and efficient treatment. However, the high cost of these systems makes them impracticable for home healthcare. This paper deals with the conceptual design and dimensional synthesis of cam-linkage mechanisms for gait rehabilitation. First, a two degrees of freedom seven-bar crank-slider mechanism is selected as the original mechanism, of which the displacement of the slider is formulated as a function of the crank angle to achieve the target trajectory by using the inverse kinematics. A cam is then designed to reduce the mobility of the mechanism to one. Moreover, a constant speed motor is sufficient for the control of the mechanism. For the dimensional synthesis, a goal function is proposed based on the kinematic performance criteria and constraints, and the genetic algorithm is employed for global searching. Two target trajectories are used for the dimensional synthesis of the mechanism. The results show the generated trajectories match well with the desired ones, which illustrates the feasibility of the methodology.

Plant can adjust its root length density and distribution pattern to optimize its resources utilization pattern.In this study,the mixed-sowing grassland of gramineous grass Avena sativa and leguminous grass Vicia villosa with the density ratio of 0:10(CK1),8:2(Ⅰ),6:4(Ⅱ),5:5(Ⅲ),4:6(Ⅳ),2:8(Ⅴ),and 10:0(CK2) was established in the upper reaches of Shiyang River in Sunan County of Gansu Province,Northwest China in 2010,aimed to study the spatial distribution patterns of root length density of the two mixed-sowing grasses.The root length density(RLD) of the two grasses was greater in mixed culture than in mono-culture.With the decrease of A.sativa density in mixed-sowing grassland,the RLD of the grass had a gradual increase,showing a phenomenon of high A.sativa density and low A.sativa RLD.Spatially,the RLD of A.sativa and V.villosa had obvious difference.A.sativa roots were mainly distributed in 0-25 cm soil layer,while V.villosa roots were concentrated in 0-15 cm soil layer.The hierarchical distribution of the roots changed their competition pattern,and the difference in the vertical distribution gradually changed the root structure and morphology.In the treatments except CK1 and CK2,the taproot growth was restrained,while the lateral root growth was promoted.The spatial hierarchical distribution of the lateral roots in the mixed-sowing grassland changed the resource utilization pattern,and gradually optimized the root length density configuration pattern,which achieved the goal of maximizing the resources utilization from soil.

蝗虫空间分布格局是物种长期适应自然的结果,是蝗虫与环境、蝗虫之间关系的反映,有助于理解蝗虫发生学的环境背景。采用地统计学方法,在黑河上游山区天然草地研究了微生境影响下的蝗虫空间格局与异质性。结果表明:该区域5种优势种蝗虫的半变异函数模型均为非线性模型,表现为聚集分布;不同种类蝗虫样点之间空间依赖的范围为2.29—24.59 m;在蝗虫种群总异质性中随机部分引起的空间异质性占15.77%—88.64%。受食性和栖息地选择的影响,蝗虫种群形成了片状和斑块状的分布格局;尺度依赖性使蝗虫分布格局趋于多元化和繁杂化的特点,不同蝗虫种群之间相互交错嵌插,同种蝗虫高低值呈非均匀扩散,整体上形成了均衡性与互补性的斑块镶嵌结构,这种分布格局反映了蝗虫对生境和气候变化的多元适应性结构。

Plant functional types(PFTs) are important in understanding the dynamics and the functions of an ecosystems,which provide also useful information for ecosystem management.In 28 observation plots of a naturally recovered poplarbirch woodland on the north slope of Qilian Mountains,China,81 plant species were classified into 18 plant functional types(PFTs),according to their life forms(including arbors,lianas,subshrub,shrub,perennial grasses,perennial forbs and annual or biennial grass) and ecotypes(including xerophyte,xerophytic and mesophytic,mesophyte and hygrophyte).The relationships between PFTs and environmental factors were studied using Canonical Correspondence Analysis(CCA).The results showed that the dominant PFTs were PFTs16(mesophytic perennial forbs),PFTs23(hygrophytic perennial forbs),PFTs9(xerophytic and mesophytic perennial forbs) and PFTs18(mesophytic shrub) on the poplar-birch restoration woodland.The stratified structure with wood,shrub and herb layers indicated the plant life forms had a tendency of complication and structurization,and the emerging mesophyte plants reflected changes of the micro-environments.The distribution patterns of PFTs were controlled by the soil physical and chemical properties in that soil bulk density,soil organic carbon and content of nitrogen determined the characteristics of the plant life forms,while the soil water moisture and canopy cover were the main ecological factors that affected the distribution of ecotypes.The slope position and slope aspect controlled the plant distribution pattern and formation of the community.Fig 1,Tab 3,Ref 31

Plastic film mulching(FM) is one of the commonly used agricultural practices worldwide in crop production.It significantly alters soil hydrothermal properties and processes such as conserving soil moisture,modifying soil chemical and physical environment,and affecting the forms of elements.Soil nitrogen plays an important role in providing necessary nutrients for crops and thus enhancing crop productivity.Its forms and transport in soil-crop systems are expected to be strongly influenced by FM.In this paper,field experiments were conducted during the winter of 2009—2010 to study the effects of FM on soil physicochemical and microbial properties,and subsequently on the distribution and translocation of nitrogen in a soil-lettuce system.The experimental plots were located in eastern China where it is typically rather moist in winter.Lettuce was grown in the plot soil and sampled following a 50-day growth.Compared to unmulching(UFM),FM had little influence on soil moisture,soil pH and urease.By comparison,FM decreased soil organic matter content by 6.0%,soil total nitrogen by 1.3% and soil NO-3-N by 10.4%,respectively,while increased soil NH+4-N by 6.5%.The one-way analysis of variation(ANOVA) showed that only soil organic matter and total nitrogen were significantly different between FM and UFM.Other soil properties were not statistically different between the two practices.In FM treatment,denitrifier accounted for 77.8—96.2% of the total nitrogen physiological microorganisms,and ammonifier,nitrite bacteria and nitrifier accounted for 1.8—16.5%,0.6—5.1% and 0.4—2.8%,respectively.As such,FM decreased ammonifier by 28.2% and increased nitrite bacteria,nitrifier and denitrifier by 119.8%,26.7% and 48.7%,respectively,as compared to UFM.In lettuce grown in the mulched soil,nitrogen was distributed the most in leaf while the least in root.While FM decreased total nitrogen in root by 2.8%,it increased total nitrogen in stem and leaf by 10.5% and 6.8%,respectively.This indicates that FM facilitated the translocation of nitrogen from root to above-ground parts.The calculated bioaccumulation factor(BCF) of total nitrogen in root,which is expressed as the ratio of nitrogen in lettuce root to that in soil,showed that FM decreased BCF by 1.5%,indicating that FM treatment decreased the total nitrogen in root.The average translocation factors TF1(TF of total nitrogen from root to stem)and TF2(TF of total nitrogen from root to leaf) were higher in FM treatment than in UFM treatment.Lower BCF may thus have resulted from higher translocation factors in FM.However,the influences of FM on the BCF of total nitrogen in root and the TFs of total nitrogen in root,stem and leaf of lettuce were statistically insignificant.This may be due to the abundance of moisture in the experimental location that FM and UFM could not be significantly distinguished in terms of BCF and TFs.The correlation analyses indicated that soil organic matter was positively significantly correlated(P0.05)with total nitrogen in soil,while nitrite bacteria had a significant negative correlation(P0.05)with urease,NH+4-N and inorganic nitrogen.

Outdoor pot or/and field experiments were conducted to investigate the influence of plastic film mulching on the soil temperature,soil pH,soil organic matter,soil microorganisms and soil activity on two types of vegetable.The pot experiments showed that the soil temperature was increased by 0.8 ℃ under plastic film mulching.And both pot and field experiments showed that under plastic film mulching,the soil moisture was increased by 6.18%~10.02%,while soil pH and soil organic matter were less affected.The amount of bacteria and fungi in mulching soil was increased by 29.0%~29.1% and 17.3%~51.9%,respectively.The behave of actinomycetes,however,was more complicated.It was decreased by 46.2% in field mulching soils,but less affected in the pot soils.The microbial community structure was less changed in pot soil,but the percentage of actinomycetes was decreased by 58.0% than the control group in field soil.Soil enzyme analysis showed that the urease was decreased obviously in the mulching soil,while the phosphatase and the catalase were less affected.