白背天葵不同提取部位抗炎活性及机制研究

为研究白背天葵不同极性部位的抗炎效果及其机制,采用LPS诱导巨噬细胞RAW264.7建立炎症模型。Griess法检测白背天葵不同极性部位对LPS诱导的RAW264.7细胞释放NO的影响;ELISA法测定细胞分泌TNF-α,IL-1β,IL-6及PGE2的含量;运用Western blot检测不同极性部位对LPS诱导的RAW264.7细胞核内NF-κB p65蛋白表达的影响。结果表明,白背天葵各极性部位均能不同程度地抑制LPS诱导的NO、TNF-α、IL-1β和IL-6的过量分泌和细胞核内NF-κB p65的蛋白表达,白背天葵正丁醇相和乙酸乙酯相能显著抑制LPS诱导的PGE2的分泌。综上,白背天葵的抗炎作用可能是通过抑制NF-κB p65通路活化,进而抑制炎症介质和促炎细胞因子的合成和释放来实现的。     

In growing pigs,nutritive value and nutrient digestibility of distillers’ by-products obtained from two varieties of rice

In South-East Asia, rice distillers’ by-product (RDP) is a widely abundant feedstuff whose adequate incorporation into pig diets is still questionable. Especially, effects of RDP on nutrient digestibility of growing pigs fed corn-soybean meal-based diet are lacking. The objective of this study was to determine nutrient digestibility and energy value of ordinary (ORDP) and glutinous (GRDP) rice distillers’ by-product in growing pigs. Two groups of 12 castrated crossbred barrows (Duroc × Landrace × Yorkshire), about 3 months old, 38?±?1.04-kg initial body weight, were each allocated to a 15-day experiment in which pigs were divided into three isonitrogenous diet-groups. The animals were housed individually in metabolism cages for separated collection of feces and urine. Each diet-group was provided either a control corn-soybean meal diet or a diet in which corn and soybean meal were partly replaced by ORDP or GRDP at 15 or 30% on diet dry matter basis. Glutinous by-product especially showed higher levels in crude protein, neutral/acid detergent fiber, total branched-chain amino acids, and butyric acid. When compared to the control diet, ORDP tented to increase DM intake (P?= 0.054) but decreased energy (P?< 0.001) and crude protein (P?< 0.04) digestibility, while GRDP decreased DM intake (P?< 0.001). Both GRDP and ORDP products negatively affected digestibility of ether extract. The average digestible and metabolizable energy of ORDP and GRDP were 17.0 and 16.6, and 17.7, and 17.1 MJ/kg DM, respectively. In conclusion, these results show that both RDP, and especially GRDP, are highly valuable protein and energy sources for pig production.

     

The c-Myc expression and apoptosis of mouse thymocytes treated with dexamethasone

AIM: To study c-Myc expression and its relationship with caspase-3 in a dexamethasone (DEX)- induced mouse thymocyte apoptosis model, and discuss the role of c-Myc in cell apoptosis. METHODS: Mouse thymocyte apoptosis was induced by 1 μmol/L DEX, the apoptotic and necrosis cells were measured by Annexin V-FITC/PI double staining flowcytometry at 30 min, 3 h, 6 h and 9 h . Electron microscopy observation was carried out at 6 h, and c-Myc and caspase-3 contents were tested by Western blot at 0, 30, 60, 180 min. RESULTS: By 1μmol/L DEX treatment, the apoptosis rates of thymocytes at 30 min, 3 h, 6 h, 9 h were (5.70±0.46)%, (35.79±1.13)%, (50.61±2.15)% and (35.52±1.66)%,respectively; in control group, they were (5.97±0.25)%, (10.20±0.71)%, (12.10±0.66)% and (15.45±0.51)% (P0.01). At same time intervals, the necrosis rates of thymocytes in DEX group were (4.58±0.51)%, (4.66±0.67)%, (25.36±1.64)% and (46.99±2.67)%; in control group, they were (4.38±0.39)%, (4.19±0.73)%, (9.63±1.25)% and (13.38±0.72)%. Typical apoptotic cells were observed at 6 h in DEX group by electron microscopy. Obvious expression of c-Myc was detected at 0 min in control group, then c-Myc content increased at 30 min and reduced at 1 h and 3 h, in DEX group, c-Myc expression was higher than that in control group, and got a peak expression at 30 min, then significantly reduced at 1h and 3 h. Caspase-3 increased following culture time lapse in control group, while its content was more in DEX group at 0 min, peak content was detected at 30 min, and significant reduction at 1 h and 3 h. CONCLUSION: These results implied a c-Myc mediated cell apoptosis pattern in the DEX- induced mouse thymocyte apoptosis model. c-Myc and caspase-3 signals may have feedback inhibitory regulation in this process.     

内蒙古赛罕乌拉自然保护区生态旅游产品体系规划

文章使用SWOT法分析了赛罕乌拉自然保护区发展生态旅游的条件,通过分析赛罕乌拉自然保护区的生态旅游资源和对赛罕乌拉的旅游市场进行细分,构建了赛罕乌拉生态旅游产品体系。整个生态旅游产品体系总共分为三个层次——基本层次、中间层次和最高层次,产品类型由观光旅游产品、游憩旅游产品、科普旅游产品、修学旅游产品和环境保护公益活动组成。另外,划定了6个重点产品：生态旅游产品、疗养休闲度假游产品、地质专项游产品、辽文化专项游产品、民族风情游产品和金代遗址游产品。     

一种番茄色选机的光学系统设计

光学系统的设计是番茄色选机中非常重要的一部分,为此,文章介绍了基于CCD传感器的光学照明系统、成像系统以及它们主要的光学参数,该系统光学结构简单,容易实现.     

4种挺水植物在高浓度氮磷污染条件下耐受性试验研究

为了探究4种挺水植物在高浓度氮、磷胁迫下对污染水体的耐受能力,人工模拟水体氮磷动态变化条件,在室外开展氮、磷耐受性盆栽试验,通过研究植物抗氧化酶防御系统中主要酶学指标超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性及丙二醛(MDA)含量,确定4种挺水植物氮、磷耐受范围.结果表明:①随着氮、磷浓度增大,4种挺水植物SO...     

中国部分新育成杂交水稻品种在几内亚适应性鉴定

本研究以几内亚主栽水稻品种为对照,对从中国引进的11个高产、优质、高抗的水稻新组合进行试验筛选。结果表明,筛选出的7个杂交水稻新组合,均表现出生育期短、株高适中、高产、优质、抗病特性。建议几内亚农业部根据不同地区雨季长短进行试验、示范及推广。优质杂交香稻组合内优香18,几农业部已请求协助解决适量种子,以期同时进行多点试验、示范。     

Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan) contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.     

北京市冬小麦节水节肥节药轻简栽培技术体系研究与应用

针对北京市小麦生产中存在的耗水量偏大、用肥量偏多、农机作业环节多、成本高等问题,引进筛选出适合北京地区使用的圆形（指针式）喷灌机等节水灌溉设备,研究提出喷灌条件下限量灌溉高效用水量为1 650m ³/hm ²,研发出用于大田水肥一体化的施肥系统,筛选出高巧和酷拉斯等4种复合拌种药剂和施用配方,引进了河南豪丰2BMSF-16/8带状免耕旋耕播种机并根据京郊播种要求进行了改造,提高了水、肥、药利用效率和农机作业效率,形成了北京市小麦节水节肥轻简栽培技术体系,包括选用抗旱品种、采用圆形喷灌机等节水灌溉,采用水肥一体化或缓释复合肥一次底施（或缓释尿素返青期一次施用）技术以减少肥料用量。该技术体系已在京郊得到大面积应用。     

植物源抗病毒制剂VA对烟草花叶病毒（TMV）体外钝化作用的？…

用植物源抗病毒制剂ＶＡ与烟草花叶病毒（ＴＭＶ）混合,经枯斑半叶法接种,结果证明,ＶＡ对ＴＭＶ有较强的体外钝化作用,体外钝化后的枯斑抑制率为８０．０％;用苯酚氯仿法提取ＴＭＶ的核酸后,按一定的比例与ＶＡ混合,经枯斑半叶法接种测得枯斑抑制率为４３．８％～７７．９％;ＴＭＶ与ＶＡ混合后用ＲＮａｓｅ处理,测得侵染率为７８．６％,比未用ＲＮａｓｅ处理的对照降低２１．４％,由此说明ＶＡ具有一定的体外脱衣壳作用