绿洲农田不同深度土壤粒径分布特性及其影响因素——以策勒绿洲为例

绿洲土壤环境变异状况及其影响因素的研究对于维护绿洲稳定、绿洲化进程的合理发展具有重要意义。以塔里木盆地南缘策勒绿洲为研究区,根据农田为绿洲主要土地利用方式的特点,通过其不同深度土壤粒径分布（PSD）物理特性的探讨,描述绿洲农田PSD的差异性,同时对其影响因素进行分析。基于绿洲范围内取样点0～20cm,20～40 cm,...     

农药使用风险案例调查与降低农药使用风险的社区培训课程开发探讨

降低农药使用风险的社区培训是一种应用剖析式、参与式调查方法对农药接触者存在的风险进行调查和分析,有针对性地开展相应的培训课程设计,从而达到降低农药使用风险的目的。通过调查使用者接触农药的途径及农户使用过程,分析了存在的风险,提出了降低农药使用风险的措施,针对农户、销售商为培训对象设计相应的课程,以期为培训者提供参考性意见和建议。     

白马雪山保护区松茸生长状况定点观测研究

通过连续4年对白马雪山保护区松茸子实体发生及生长状况进行监测,监测内容包括子实体发生数量、生长周期、空间位置变化,并此基础上分析了坡度、坡向、植被类型、降雨量与松茸子实体发生及生长状况的关系。     

Microinjection of AT1 and AT2 receptor antagonists into PVN affects renal sympathetic nerve activity in chronic heart failure rats

AIM: To examine the renal sympathoexcitation affected by microinjection of angiotensin Ⅱ type 1 (AT₁) receptor antagonist L-158809 and angiotensin Ⅱ type 2 (AT₂) receptor antagonist PD123319 into paraventricular nucleus (PVN) in heart failure rats.METHODS: Left anterior descending coronary artery ligation was used to induce rat heart failure (HF) . Four weeks after operation, the left ventricular end-diastolic pressure (LVEDP), the ratios of heart weight/body weight and lung weight/body weight, and the ratio of infarct area of the left ventricle were observed. Under anesthesia, SD rats were fixed into the brain stereo controller to locate PVN for microinjection and the artificial cerebrospinal fluid (ACSF) was used for control. The left kidney was exposed by retroperitoneal approach and the renal sympathetic nerve was separated under surgical microscope. The heart rate, blood pressure and the activity of renal sympathetic nerve discharge (RSNA) were recorded by POWERLAB 8/30 system. RESULTS: Microinjection of AT₁ receptor antagonist into PVN induced a decrease in RSNA in both HF rats and sham rats. The RSNA responses to L-158809 in the HF rats were significantly greater (P<0.05) than those in the sham rats. However, microinjection of AT₂ receptor antagonist and ACSF into PVN induced no change of RSNA in both HF and sham rats. CONCLUSION: There are some differences of sympathetic nerve outputs between using AT₁ receptor antagonist and AT₂ receptor antagonist on PVN, indicating the up-regulation of AT₁ receptors in PVN during HF. The central renin-angiotensin-aldosterone system(RAAS) may be affected by AT₁ receptor, not by AT₂ receptor.     

全国营造林综合核查技术体系与抽样方法

简述全国营造林综合核查发展背景,介绍综合核查技术体系的形成与发展、设计原则、基本框架、运行管理以及抽样方法。     

Expression of zinc-finger transcription factor Snail 1 in the kidney of diabetic rats

AIM: To explore the expression of Snail 1 in renal tissues of diabetic rats, and to investigate its contribution to the progression of diabetic nephropathy. METHODS: Streptozotocin-induced diabetic rats were randomly divided into 2, 4, 8, 12, 16, 20, 24 weeks groups and 16 week A, 20 week A and 24 week A groups. A groups were treated with insulin to control blood glucose to normal level from the 13th week. Control groups were set up in age-matched time points. Blood glucose, 24 h urine protein, serum creatinine (Scr) and kidney index of rats were measured. Periodic acid-silver (PAS) staining was used to observe the renal pathological changes. The mRNA and protein expressions of Snail 1 and FN in renal cortex were detected by RT-PCR and immunohistochemical staining, respectively. Western blotting was employed to detect the expression of Snail 1 protein in the renal cortex. RESULTS: The levels of blood glucose, Scr, kidney weight index were increased remarkably in diabetic rats as compared with those in control groups (P<0.05, P<0.01), and decreased remarkably in the insulin-treated rats as compared with those in the diabetic rats (P<0.05, P<0.01). The Snail 1 protein was not detected by immunohistochemical staining in normal renal tissues. However, strongly positive staining was observed in renal tubules of diabetic rats. A time-dependent loss of Snail 1 expression was detected in the kidney in insulin-treated rats. The Snail 1 protein and mRNA of Snail 1 and FN were significantly up-regulated in the diabetic rats as compared with those in controls (P<0.01), while down-regulated in the insulin-treated diabetic rats (P<0.01). A close positive relationship existed between the mRNA expression of Snail 1 and FN (r=0.800, P<0.01). The level of Snail 1 protein expression was positively correlated with blood glucose, urine protein, Scr, kidney index (r=0.877, 0.694, 0.522, 0.875, P<0.01).CONCLUSION: These findings suggest that Snail 1 gene and protein expression are up-regulated in the kidney of rats with diabetes and may be involved in the pathogenesis of diabetic nephropathy.     

RAPD标记技术及其在牧草研究中的应用

介绍了RAPD标记的发展、原理、方法、特点和不足，并且对它在遗传图谱的构建、基因定位、品种和品系的分类及鉴定、作物育种等研究领域中的应用作一简述。     

直接式加热炉炉管表面腐蚀原因分析

对直接式原油加热炉进行大修解剖发现,加热炉对流炉管腐蚀严重,通过对对流炉管表面腐蚀产物成分及产生腐蚀的原因进行分析,指出高温燃烧条件下炉管表面发生强烈氧化和硫酸露点腐蚀是造成对流炉管表面腐蚀的主要原因,并提出了防止炉管腐蚀的改进措施,确保加热炉的安全运行。     

国内蛋白质饲料资源开发利用的现状及前景

综述目前国内蛋白质饲料产品的现状,提出新的蛋白质饲料资源开发的建议。     

Biological control of rice disease and insect by chifinase-producing bacterium X2-23

Enriched by the medium containing chitin and cell wall of Rhizoctonia solani AG-1, a bacterium X2-23 with higher chitinase activity was isolated from 166 chitinase-producing bacteria.