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1.
渭河流域大型底栖动物群落结构及其与环境因子的关系   总被引:8,自引:0,他引:8  
于2011年10月对渭河流域45个采样点的大型底栖动物进行调查采样.共采集到大型底栖动物116属(种),其中水生昆虫91(属)种,占78.4%;软体动物12种,占10.3%;环节动物9种,占7.8%;甲壳动物4种,占3.4%.利用大型底栖动物的物种组成以及物种相对丰度数据,应用双向指示种分析和无偏对应分析将45个样点分为3组.第1组样点的指示物种为锯形蜉属1种(Serratella sp.)、纹石蛾属1种(Hydropsyche sp.)和朝大蚊属1种(Antochasp.);第2组样点指示物种为虻属1种(Tabanus sp.)、Alotanypus venustus、Pelecorhynchidae 1 种、Liodessus sp.和霍甫水丝蚓(Limnodrilus hoffineistteri);第3组指示物种为黑翅蜉(Ephemera nigroptera)和半球多脉扁螺(Polypylis hemisphaerula).典范对应分析表明,卵石+砾石型底质、流速、电导率、水深和总氮显著影响了渭河流域底栖动物群落的空间分布.  相似文献   
2.
渭河丰、枯水期底栖动物群落特征及综合健康评价   总被引:6,自引:0,他引:6  
殷旭旺  李庆南  朱美桦  宋佳  武玮  徐宗学 《生态学报》2015,35(14):4784-4796
以渭河为研究范例,分别于丰水期(2011年10月)和枯水期(2012年4月)对渭河全流域范围内45个样点的底栖动物群落进行跟踪调查,并在此基础上应用丰、枯水期底栖动物生物完整性评价指数(B-IBI)对渭河流域水生态系统进行综合健康评价。结果表明,渭河流域底栖动物群落结构具有明显的空间异质性,枯水期底栖动物群落结构单一,物种数量、生物量和香农多样性明显少于丰水期,但单位密度差异不显著。综合健康评价结果表明,渭河上游、洛河中上游地区的健康状况较好,而渭河中下游、泾河全流域及洛河下游地区的健康状况较差。相关分析显示,渭河全流域范围内丰水期和枯水期底栖动物群落的B-IBI得分呈现明显的正相关性,表明在不同水文过程时期,渭河全流域大尺度范围内底栖动物群落的生物完整性特征较为一致。在河流丰、枯水期,底栖动物群落结构的变化趋势并对比分析了渭河流域不同区域水生态系统健康水平差异的原因。  相似文献   
3.
目的:观察贝伐珠单抗联合化疗对晚期非小细胞肺癌患者的疗效、安全性及影像学改变。方法:对2007年至2014年于我院治疗的晚期NSNSCLC(非鳞非小细胞肺癌non-squamous non-small cell lung cancer)患者,给予贝伐珠单抗(15 mg/kg或7.5mg/kg)联合化疗(紫杉醇175 mg/m~2,d1,卡铂AUC=5或6,d1,q3 w)6周期及贝伐珠单抗维持治疗(15 mg/kg或7.5 mg/kg,d1,q3w)。观察疗效、不良反应、肺部病灶空洞改变的情况、恶性胸腔积液的治疗效果及部分患者EGFR、KRAS基因突变状况。结果:共观察26例患者,均接受贝伐珠单抗联合化疗,17例行贝伐珠单抗维持治疗。部分缓解(partial response,PR)、疾病稳定(stable disease,SD)、疾病进展(disease progression,PD)率分别为53.8%、42.3%、3.8%。中位无进展生存期(progression free survival,PFS)为11.0个月,中位总生存期(overall survival,OS)达25.8个月。26例患者中15.4%治疗后病变发生空洞改变,空洞组的2年、3年生存率略高于无空洞组,但无统计学差异(P值分别为0.586、0.509)。13例患者伴有恶性胸腔积液,胸腔积液的疾病控制率为100%。11例患者标本可进行EGFR基因检测,敏感突变占36.4%,未突变占63.6%。对10例患者标本行KRAS基因检测,均为突变阴性。不良反应包括骨髓抑制、消化道反应、鼻衄、咯血、高血压、蛋白尿等。大多数不良反应程度较轻,可控制。结论:贝伐珠单抗联合化疗治疗晚期NSNSCLC患者疗效确切,副反应可耐受,控制恶性胸腔积液效果较好。肺部病灶空洞改变的临床意义有待进一步研究。  相似文献   
4.
武玮Lin 《动物学报》1995,41(2):173-180
用微电极细胞内记录技术研究了东方蝾螈胚胎表皮细胞膜的静电位、输入电阻与其兴奋性的关系,在兴奋性形成期间正常胚胎表皮细胞的静息膜电位逐渐增大,膜的输入电阻逐渐减小。与不显示兴奋性的离体非典型胚胎表皮细胞相比,显示兴奋性的膜电位较高,膜电阻较低。用葡萄糖处理非典型表皮,在兴奋性出现同时,细胞膜超极化,膜电阻减小。用哇巴因处理表皮囊泡,在兴奋性消失同时,细胞膜去极化。结果表明,细胞能量供应不足所造成的膜  相似文献   
5.
山西油松自然类型的划分及其性状的差别分析   总被引:1,自引:0,他引:1  
从油松的形态变异调查入手,提出了划分油松自然类型的主要依据是冠幅大小与树皮厚度。据此,将山西灵空山地区油松划分为窄冠细皮油松和宽冠粗皮油松两种自然类型,并分类型进行了生长测定。采用Fisher判别分析,验证了对油松划分两种自然类型的正确的。还可应用判别函数Y=0.0653X-4.0369X2+0.0126X3与判据Yc=-0.3668,判别调查地区的油松自然类型。经F检验判别函数的效果,达到了90  相似文献   
6.
影响有尾类离体胚胎表皮细胞兴奋性的实验   总被引:1,自引:0,他引:1  
It has been reported that in Cynops orientalis the cells in the atypical epidermis resulted from isolation of the ectoderm from the early gastrula and cultured in vitro possesses very low excitability. The great majority of the explants didn't display action potential (AP) with electric stimulus up to 6 V duration 1 ms). If, however, the epidermis was taken from the flank region of a neurula with the underlying mesoderm, in such explant the epidermis cells became excitable at a lower threshold of stimulus. The mesoderm seemed to exert some influence upon the epidermis. In order to study whether tissues other than mesoderm possess similar effect on the excitability of epidermis cells, different combinations of explants were made with the experimental embryological technique and their excitability was examined electrophysiologically. In all experiments the explants were stimulated extracellularly and the action potential was recorded intracellularly. The specimens were stimulated with electric stimulus at 6 V at first, and, if they displayed AP the strength was lowered to determine the threshold of stimulus to evoke AP. The duration of stimulus was fixed at 1 ms. For the control of all series, the ectoderm or epidermis was isolated at the same stage and cultured for the same length of period as the experimental explants but without any treatment. 1). The effect of calf serum. In this group the effect of calf serum was examined and following series were carried out: a) Gastrula ectoderm cultured in Holtfreter solution containing 10% calf serum; b) calf serum + agar as implant: calf serum was mixed with agar (1:1) and cut into small pieces when cooled, and the serum + agar pieces were wrapped with ectoderm; c) heated serum + agar, heated serum was mixed 1:1 with agar and the small pieces were wrapped with ectoderm. In all the experiments the excitability of the epidermis cells was raised more or less but the agar pieces containing fresh serum seemed to be more effective, perhaps due to the higher concentration of the serum and the intimate contact with the epidermis cells (Tab. 1) In the series with serum + agar as implant and in the series with heated serum + agar as implant, it occurred frequently that during cultivation the implants will be extruded and after the extrusion of the implant the remaining epidermis became less sensitive to stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
7.
目的:探讨贝伐珠单抗联合紫杉醇/卡铂方案治疗晚期非小细胞肺癌的临床疗效和安全性.方法:选择本研究中心入组SAiL (MO19390)研究的13例患者为研究对象,给予贝伐珠单抗15 mg/kg,化疗d1静点,以后每3周重复;联合化疗方案为175mg/m2紫杉醇,d1,卡铂AUC=6,d1,每3周重复.化疗4-6周期,贝伐珠单抗每3周应用一次直至病情进展.评价患者的不良反应、客观有效率(objective response rate,ORR)、中位无进展生存期(progression free survival,PFS)和总生存期(overall survival,OS).同时,对可取得肿瘤组织标本的患者进行回顾性EGFR和KRAS突变检测.结果:13例患者中,发生5级肺动脉栓塞1例,4级脑梗塞1例,4级蛋白尿2例,3级鼻出血1例,最常见的不良反应为鼻出血(69.2%)、蛋白尿(46.2%)、高血压(38.5%)、咯血(30.8%)、流涕(30.8%)、头晕(23.1%),大多程度较轻可以耐受.部分缓解(partial response,PR)7例(53.8%),疾病稳定(stable disease,SD)6例(46.2),总有效率53.8%,疾病控制率100%,中位PFS 7.7个月,中位OS 16.1个月.6例可进行EGFR和KRAS突变检测的患者中,1例存在EGFR 19外显子缺失突变,1例存在21外显子L858R点突变,4例未检测到EGFR敏感突变,6例患者KRAS突变均为阴性.结论:贝伐珠单抗联合紫杉醇/卡铂方案治疗中国晚期非小细胞肺癌可延长PFS和OS,患者的耐受性良好.  相似文献   
8.
It has been reported that the cells in atypical epidermis, which developed from the in vitro cultured ectoderm isolated at early gastrula, showed very low excitability or were even non-excitable at 6 V when examined electro-physiologically. If non-excitable explants were treated with energy supplying substances, such as glucose, the action potential (AP) appeared quickly. It indicates that, the excitability of epidermis cells is related to their energy metabolism. In order to verify the above proposition the effects of metabolic inhibitors on the excitability of the epidermis cells were examined using electrophysiological technique. Two kinds of explants were used: explants which developed from the epidermis underlaid with mesoderm isolated at early neurula (epidermis vesicle) and explant which developed from the ectoderm isolated at early gastrula (atypical epidermis). In all experiments explants were stimulated extracellularly and APs were recorded intracellularly. The specimens were stimulated with electric stimulus at 6 V first, and, if they displayed AP, the strength was lowered to determine the stimulus threshold to evoke AP. The duration of stimulus was fixed at 1 ms. The ratio of the resting potential value during treatment to the original value was taken as index of change level of the resting potential (RP). During treatment of epidermis vesicle with 1 mM NaN3 or 1 mM NaCN or 0.1 mM 2,4-dinitrophenol (DNP), the excitability of the epidermis cells was reduced: the stimulus threshold gradually increased and the cells in most explants lost the excitability. The cells became excitable after the drugs were washed out.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
9.
利用细胞核移植技术将NIH3T3细胞核和孤雌桑椹胚单个卵裂球,分别移植到去核MⅡ期受体卵母细胞中,通过免疫荧光染色后比较体外受精胚、孤雌胚、NIH3T3核移植重组胚和孤雌桑椹胚核移植重组胚附植前各时期胚胎DNA甲基化水平的变化,以探明克隆胚细胞核去分化与DNA甲基化的相互关系.利用Real-timePCR技术检测体外受精胚、孤雌胚和孤雌桑椹胚核移植重组胚附植前各时期胚胎中,印记基因U2afbp-rs基因以及非印记基因eIF-4C基因表达量的变化,以探明小鼠卵细胞质对克隆胚细胞核中印记基因表达的调控.结果表明,克隆胚供体核基因组DNA在核移植后并没有发生主动去甲基化.孤雌桑椹胚核移植后重组胚中U2afbp-rs基因和eIF-4C基因的表达水平要显著低于对照孤雌胚,但其表达量变化规律与对照孤雌胚相同,说明了卵细胞质对供体核印记基因的表达具有一定的调控作用.  相似文献   
10.
目的:培美曲塞是一种多靶点抗叶酸化疗药,目前已成为晚期非小细胞肺癌二线治疗的标准药物.本研究回顾分析培美曲塞单药或联合铂类治疗晚期复治非小细胞肺癌的疗效及不良反应.方法:对既往至少接受过1个标准含铂方案化疗的54例晚期非小细胞肺癌怠者,分为单药治疗组21例,联合铂类治疗组33例.单药治疗组给予培美曲塞单药治疗,培美曲塞500mg/m2,第1天,21天为1个周期;联合铂类治疗组给予培美曲塞联合顺铂或卡铂,培美曲塞500mg/m2,第1天,顺铂75 mg/m2或卡铂AUC=5,第1天,21天为1个周期.评价疗效及不良反应.结果:54例患者均可评价疗效.单药治疗组PR 1例,RR4.8%,SD10例,疾病控制率(DCR)52.4%,PD10例(47.6%).中位无进展生存期3.8个月;联合治疗组PR4例,RR12.1%,SD20例,疾病控制率(DCR)72.7%,PD9例(27.3%).中位无进展生存期4.8个月.与药物相关的不良反应主要为:Ⅰ/Ⅱ度骨髓抑制、胃肠道反应.结论:培美曲塞或与铂类联合治疗晚期复治非小细胞肺癌有效,不良反应轻微、可耐受.  相似文献   
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