Changes of large-conductance calcium-activated potassium channel in gastric smooth muscle cells of diabetic gastroparesis rats

AIM: To discuss the relevance between the pathogenesis of diabetic gastroparesis and the large-conductance calcium-activated potassium channels (BK_Ca) in gastric smooth muscle cells. METHODS: The SD rats were randomly divided into control group and model group. The gastric smooth muscle cells of the SD rats were enzymatically isolated in a low calcium solution containing papain. The current was recorded by patch clamp single channel recording technique. The expression of KCNMA and KCNMB1 were observed by the method of immunohistochemistry. RESULTS: The value of BK_Ca single channel conductance was (220.10±10.90) pS; the channels had distinct voltage dependent and calcium dependent characteristics. In outside-out patch (Vm =+30 mV), the activation of BK_Ca was blocked by 200 nmol/L IbTX completely. Compared with control group, the open probability and amplitude of current in model group significantly increased, while the mean open time and mean close time significantly decreased. Compared with control group, the expression of KCNMB1 in model group was significantly increased. CONCLUSION: Up-regulation of β1-subunit and increase in BK_Ca functional activities may be associated with diabetes gastroparesis in rats.     

硅钾复合肥在牛奶葡萄上的应用研究

通过硅钾复合肥在牛奶葡萄上的研究试验.结果表明:硅钾复合肥不仅能够有效促进葡萄植株的生长,提高其抗病力,增加葡萄果实的单果重,而且对提高葡萄果实的含糖量,降低其酸度有显著作用.     

Nonexchangeable Potassium Displacement in Relation to Potassium Availability to Rainfed Maize under Nitrogen Fertilization

A study was conducted to evaluate the effect of nitrogen (N) application, through an easily available and cheap source urea, on potassium (K) displacement and its availability in K-deficient maize-growing soils of rainfed subtropics. The greatest amount of K was displaced (11.22 kg ha^?1) by N application at the rate of 80 kg N ha^?1 (treatment T₄). Amount of N fixed to displace K (11.10 kg ha^?1) was also greatest in the same treatment. Displaced K was positively related to nonexchangeable potassium (NEK) release. Nitrogen application through urea at 80 kg ha^?1 helped not only in meeting N requirement of maize crop in these N-deficient soils but can also satisfy the K requirements (as these soils are low in K) of these soils. Potassium displacement also increased the production efficiency of the maize crop by promoting its relative production efficiency index (RPEI) from suitability class V to class III.     

Analysis to On-off Voltage Wave and Its Parameter of Switched Power

To analyse the working parameter of switched power, this article introduces the circuit model of switched power and the shaping process of its on off voltage wave. Aiming at analyzing to the voltage wave and parameter, an "assistant compensation" method is put forward. Based on this method, the voltage wave and parameter of switched power are theoretically analyzed and imitated. The imitation results indicate that the method is afeasible and advance one.     

黄土丘陵区不同地貌类型地球化学分布特征

根据宁夏南部黄土丘陵区彭阳古城乡黄土梁峁—茹河河谷剖面和西吉城郊乡黄土梁峁—葫芦河河谷剖面土壤样品地球化学测试的结果,分别对不同地貌部位的常量元素、微量元素和微量元素有效态的含量进行了对比研究。大多数常量元素比较稳定,K+、Na+在河谷阶地区富集,在黄土梁峁及边坡流失;CaO和Fe2O3由于土壤水的作用和氧化还原条件的不同,其含量在河谷阶地区较少;大多数微量元素在土壤中比较稳定,Ti、P、V、Zn和Ba等元素的含量:黄土丘陵梁峁顶部<河谷阶地;B在土壤中的含量:黄土丘陵梁峁顶部>黄土丘陵梁峁边坡>河谷阶地;微量元素的有效态含量:河谷阶地>黄土丘陵梁峁顶部>黄土丘陵梁峁边坡。     

大豆品种丹豆8号播期试验研究

于1999、2000年两年在丹东农业科学院大豆研究所对大豆品种丹豆8号进行不同播期试验。对大豆的出苗期、苗情、结英部位、籽粒霜霉病、特别是产量进行调查研究。分析表明,在丹东地区,丹豆8号5月上旬播种较为适宜。     

Control of postharvest diseases of rambutan using controlled atmosphere storage and potassium metabisulphite or<Emphasis Type="Italic">Trichoderma harzianum</Emphasis>

Botryodiplodia theobromae, Colletotrichum gloeosporioides andGliocephalotrichum microchlamydosporum are the causal fungi of three rambutan postharvest diseases, stemend rot, anthracnose and brown spot, respectively. Two different treatments of rambutan fruits to control the diseases were investigated: application of potassium metabisulphite (250 ppm) or culture filtrate ofTrichoderma harzianum (TrH 40) followed by controlled atmosphere storage (CA) at 13.5°C and 95% r.h. Potassium metabisulphite at 250 ppm under CA effectively controlled the incidence and severity of the three postharvest diseases and maintained the eating quality and color of the fruit for 21 days. The greatest effect of this treatment was on brown spot disease, caused byG. microchlamydosporum. Application of TrH 40 was less effective than potassium metabisuphite. http://www.phytoparasitica.org posting July 8, 2002.     

南美斑潜蝇各虫态发育历期及有效积温的研究

在不同恒温条件下测定了南美斑潜蝇的发育历期。采用直线回归法计算出卵、幼虫、蛹和整个世代的发育起点温度分别为 7 9、6 2、7 5、和 7 0℃ ,有效积温分别为 42 6、98 5、1 47 9和 2 91 7日度。在乌鲁木齐地区 1年可发生 7代。     

农业品牌培育的有效途径及策略

近年来,我国农业领域日益重视品牌培育。农业品牌有力地推动了农业经济发展,有利于构建现代化的农业体系。因此,农业相关企业需要重视品牌培育。该文主要研究农业品牌培育的有效途径及策略。     

氯钾离子共体诱导黄瓜抗霜霉病方法的研究

黄瓜经氯钾离子共体诱导后,霜霉病的发病程度显著降低,不同的诱导方法产生不同的诱导效果,同种方法下不同的处理浓度所产生的诱导效果也不同。本试验采用灌根、叶面喷施、茎部注射、种子浸泡4种诱导方法,每种诱导方法下又分5个不同的处理浓度。试验结果表明灌根诱导效果最好,叶面喷施诱导效果较好,其次为茎部注射、种子处理,它们的平均相对免疫效果分别达到47．63％、28．9z％、16．95％、14．32％,在每种诱导方法下诱导抗性最佳的处理浓度叶面喷施为1％和1．5％;灌根诱导为1％;茎部注射为2％;种子浸泡为8％。