222 resultados para 206-1256


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东灵山地区年均降水量659.7mm,单次降水以雨量小、雨强低的降水为主。水汽压(年均17.7mb)、相对湿度(年均66%)的季节变化呈现生长季高、冬季低的趋势。年均蒸发量1019.5mm;气温、风速、日照时间和水压与月蒸发量和日蒸量相关显著;气温、日照时间和水压分别在11-6月、7-8月和9-10月为决定蒸发量的首要因子。枯枝落叶层、土壤层湿度主要受前十日降水量和坡向影响。 植物体含水量生长季节较高,冬季较低;含水量随径级的增大而降低。六个灌木树种的平均含水量大小顺序为:毛榛(48.62%)最高荆条(36.32%)最低;七个乔木树种水分含量为油松,56.14%;蒙椴,54.19%;华北落叶松,52.91%;五角枫,43.64%;辽东栎,41.87%;棘皮桦,41.13%;大叶白腊,37.79%。几种植被类型的储水量为:辽东栎林,82.08mm;华北落叶松林,47.35mm;混交林,34.60mm;油松林,31.33mm;灌丛,12.40mm。各树种叶片日最低水势的季节均值为:辽东栎,-16.1bar;五角枫,-15.8bar;大叶白腊,-15.1bar;糠椴,-13.4bar;棘皮桦,-12.3bar;蒙椴,-12.2bar。叶片水势的日间变化均呈一“V”形曲线;光照在叶片水势的日间变化中起着决定性作用。 96年各树种平均单株树干茎流量为辽东栎,30.3mm(4.19%);华北落叶松,16.1mm(2.22%);油松,8.9mm(1.23%);棘皮桦,2.9mm(0.40%)。两个生长季各林分冠层的水量平衡为:辽东栎林,树干流茎量101.87mm(9.18%),穿透降水量823.08mm(74.15%),截留量185.05mm(16.67%);华北落叶松林,树干径流量66.88mm(6.03%),穿透降水量836.92mm(75.40%),截留量206.20mm(18.58);混交林,树干径流量50.13(4.52%),穿透降水量846.78mm(76.29%),截留量212.20mm(19.12%);油松林,树干径流量33.90mm(3.05%),穿透降水量934.88mm(84.22%),截留量141.22mm(12.72%)。多元回归分析表明,树干流茎量S与降水量P和前24小时降水量P_1呈显著正相关关系;穿透降水量T与降水量P和最大雨强M正相关显著。附加截留量与降水时间成正比。 枯枝落叶层的生物量为:油松林,25.56t/hm~2;华北落叶松林20.01t/hm~2;辽东栎林,8.31t/hm~2;混交林,7.98t/hm~2。枯枝落叶层的平均实际持水量和有效持水量均以油松林最大,其次是华北落叶松林,而混交林和辽东栎林较低;枯枝落叶层的实际持水量和有效持水量的季节变化分别与前十日降水量P10成正相关和负相关关系。枯枝落叶层的截留量为油松林>华北落叶松林>辽东栎林>混交林;油松林(145.632mm和90.800mm)混交林(61.816mm和54.504mm)。油松林、辽东栎林、混交林和华北落叶松林去除枯枝落叶层后,土壤入渗量比对照平均降低100mm以上;表层土壤含水量分别比对照土壤下降了6.26、18.26、15.06和15.07个百分点。地表径流量分别增加了,辽东栎林34.299mm(603%)和15.816mm(525%);油松林14.593mm(732%)和10.584mm(1321%);混交林12.004mm(181%)和7.275mm(364%);华北落叶松林3.555mm(118%),3.275mm(229%)。96年生长季,各土壤流失量分别增加了:油松林172.751t/hm~2(124倍);辽东栎林836.500t/hm~2(119倍);混交林172.499t/hm~2(47倍);华北落叶松林11.557t/hm~2(11倍)。表层土壤容重分别增加了:油松林15.0%和20.6%,辽东栎林18.4%和28.2%,混交林11.5%和38.5%,华北落叶松林4.3%和17.1%。 0-60cm深度土壤容重平均值的大小顺序为:草地>灌丛>辽东栎林>油松林>混交林>华北落叶松林;而土壤孔隙度的大小顺序为华北落叶松林>混交林>油松林>辽东栎林>灌丛>草地。两个生长季为土壤实际储水量的均值:油松林,124.45mm,78.62mm;辽东栎林,131.23mm,87.72mm;混交林,180.41mm,113.90mm;华北落叶松林,165.53mm,127.95mm;灌丛,172.50mm,89.81mm;草地,152.92mm,89.59 mm分别比干旱年份97年高出45.83mm、43.51mm、51.63mm、37.58mm、82.69mm和63.33mm。两个生长季的地表径流量为草地,30.930mm(2.79%);灌丛,16.321mm(147%);油松林,2.911mm(0.26%);辽东栎林,8.703mm(0.78%);混交林,8.625mm(0.78%);华北落叶松林,4.447mm(0.40%)。油松林、混交林和华北落叶松林地表径流量与降水量P(mm)和最大雨强(mm/h)正相关显著;而辽东栎林、灌丛和草地的地表径流量则与降水量P(mm)、平均雨强Q(mm/hr)和最大雨强M(mm/hr)三者之间呈显著正相关关系。与草地相比(1220.093kg/hm~2,100%),灌丛、辽东栎林、混交林、油松林和华北落叶松林96年生长季的土壤流失量分别降低了85.05%、94.26%、96.99%、98.86和99.14%。 降水量是影响小流域径流量时间变化的主要因素;南沟和马牙石沟96年的径流量分别是97年的8.19倍和7.87倍,而径流深(46.25mm,52.75mm)分别比97年(5.65mm,6.70mm)高出40.60mm和46.05mm。两个小流域由于面积的差异而使南沟两年的径流量分别比马牙石沟高出2773.136m~3(13.15%)和235.434m~3(8.79%)。96年和97年马牙石沟径流深比南沟高出6.5mm(14.05%)和1.05mm(18.58%)。在地处大陆性季风气候区的东灵山地区,用0.010m~3/min/km~2/hr能较好地分割小流域的洪峰和基流。在五次暴雨水文曲线中,马牙石沟的快速径流量分别比南沟高出25.00%到143.33%。五次洪水水文响应R的平均值南沟为0.218%,马牙石沟为0.404%;与海洋性气候地区相比,东灵山地区小流域的R值要低一到两个数量级。马牙石沟洪峰流量Qp的平均值为418.772L/min要比南沟(281.191L/min)大48.9%。东灵山地区小流域的洪水径流过程可分为三种类型。

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Spermiogenesis is a unique process in mammals during which haploid round spermatids mature into spermatozoa in the testis. Its successful completion is necessary for fertilization and its malfunction is an important cause of male infertility. Here, we report the high-confidence identification of 2116 proteins in mouse haploid germ cells undergoing spermiogenesis: 299 of these were testis-specific and 155 were novel. Analysis of these proteins showed many proteins possibly functioning in unique processes of spermiogenesis. Of the 84 proteins annotated to be involved in vesicle-related events, VAMP4 was shown to be important for acrosome biogenesis by in vivo knockdown experiments. Knockdown of VAMP4 caused defects of acrosomal vesicle fusion and significantly increased head abnormalities in spermatids from testis and sperm from the cauda epididymis. Analysis of chromosomal distribution of the haploid genes showed underrepresentation on the X chromosome and overrepresentation on chromosome 11, which were due to meiotic sex chromosome inactivation and expansion of testis-expressed gene families, respectively. Comparison with transcriptional data showed translational regulation during spermiogenesis. This characterization of proteins involved in spermiogenesis provides an inventory of proteins useful for understanding the mechanisms of male infertility and may provide candidates for drug targets for male contraception and male infertility.

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The complete mitochondrial genomes of the primary cancerous, matched paracancerous normal and distant normal tissues from 10 early-stage breast cancer patients were analyzed in this study, with special attempt (i) to investigate whether the reported high

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目的 研究脱抗原水牛角胎移植后的免疫排斥反应和成骨效应。方法 以日本大耳白兔为动物模型,分别植入经30% H_2O_2、0.6 mol/L HCl脱抗原脱钙,30% H_2O_2脱抗原不脱钙2种温和方法处理的水牛角胎至兔左侧肢骨缺损处。体外检测外周血特异性T淋巴细胞转化率和ELISA检测血清特异性抗角胎IgG抗体。结果 脱抗原脱钙处理显著地降低了角胎的抗原性,与对照相比,未见受体对移植物产生显著的特异性细胞和体液免疫反应(P > 0.05),尤其是脱抗原不脱钙角胎效果更佳。两者成骨效果均良好。结论 脱抗原角胎是一种免疫原性低、成骨效果好、来源方便的骨移植材料。

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Tongjiang cattle are a local cattle population of Sichuan Province, China, numbering approximately half a million in 2005. They have long been grouped into the Bashan breed, although they have a unique breeding history and phenotypic characteristics, as w

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在云南景谷芒果种植区, 芒果炭疽病对芒果树嫩叶、嫩梢、花穗和果实为害率分别为85.7%、63.4%、77.1%和73.3%。风雨和昆虫媒介是传播的主要方式。发生为害最适温度为22℃--25℃, 相对湿度为85%--100%。该病在景谷种植区全年均可发生为害, 主要为害在发生期。发生前期为害, 是花穗干瘪和幼果掉落的原因之一。采取综合防治措施, 特别在发生前期适时防治, 可控制发生为害。

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 目的 观察单核细胞、NK细胞和T 细胞在猪2猕猴延迟性异种移植排斥反应(DXR) 中的作用。方法 建立湖北白猪2云南猕猴的腹腔异位心脏移植模型,实验分为2 组:对照组( n = 5) ,不使用中华眼睛蛇毒因( Y2CVF) ;实验组( n = 4) 应用Y2CVF 完全清除受者体内补体。2 组受 体猴均采用环孢素A(CsA) ,环磷酰胺(CTX) 和甲基强的松龙(MP) 三联免疫抑制治疗。免疫组织 化学方法检测移植心组织中细胞间黏附分子( ICAM)21 、肿瘤坏死因子( TNF)2α、单核细胞、NK 细 胞和T 细胞的表达。结果 对照组3 个移植心在15~60 min 内发生超急性排斥反应(HAR) ,另2 个分别存活22 h 及6 d ,移植心均未见明显的炎性细胞浸润及ICAM21 和TNF2α的表达。实验组 移植心存活时间分别为8 、10 、13 和13 d ,移植物浸润细胞中可见大量的单核细胞(50 %) ,少量的 NK细胞(8 %~10 %) ,CD4 + T 细胞(15 %) 和CD8 + T 细胞(25 %) 。移植物血管内皮细胞表面出现 ICAM21 的表达上调,移植物间质中出现TNF2α的表达增加。结论 单核细胞、NK细胞和T 细胞 介导的移植物损伤,在应用Y2CVF 处理的猪2猕猴DXR 发生中发挥重要作用 

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14周龄雄性昆明种小白鼠颌下腺摘除后第4周开始,附睾内精子数量呈显著减少趋势,第5和第6周的精子数分别为0.56±0.26×10~(7)和0.50±0.13×10~(7),与对照相比分别有显著差异( P<0.05)和非常显著差异( P<0.01)。摘除颌下腺手术后5周内小鼠的体重与对照相比无显著变化,但第6周的体重下降有明显的统计学差异( P<0.01)。

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Recurrence is a key characteristic in the development of epilepsy. It remains unclear whether seizure recurrence is sensitive to postseizure stress. Here, tonic-clonic seizures were induced with a convulsive dose of pentylenetetrazole (PTZ), and acute seizure recurrence was evoked with a subconvulsive dose of the drug. We found that stress inhibited seizure recurrence when applied 30 minutes or 2 hours, but not 4 hours, after the tonic-clonic seizure. The time-dependent anti-recurrence effect of stress was mimicked by the stress hormone corticosterone and blocked by co-administration of mineralocorticoid and glucocorticoid receptor antagonists. Furthermore, in a PTZ-induced epileptic kindling model, corticosterone administered 30 minutes after each seizure decreased the extent of seizures both during the kindling establishment and in the following challenge test. These results provide novel insights into both the mechanisms of and therapeutic strategies for epilepsy. (C) 2010 Elsevier Inc. All rights reserved.

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首先用从头算方法计算缬氨酸两性离子同处于160种不同位置的水分子的相互作用能, 计算 时采用最小基组并进行了基组重叠修正, 最后对计算得的相互作用能Slater-Kirkwood 公式作色散能修正; 然后进行势函数的拟合, 即舍弃12个相互作用能大于5Kcal/mole或原子间距离小于1.68A的布点, 对其余148个布点进行拟合。拟合结果的标准偏差为SD=0.48Kcal/mole。图1表3参13