高压静电场处理家蚕卵对蚕茧产量和质量的影响

通过实验室试验和生产中试,探讨了高压静电场处理家蚕卵对幼虫生命力、蚕茧产量及茧丝质量的影响。实验室试验结果表明,采用的2个加速电压处理组及4个无加速电压处理组对蚕的孵化和生命力均无不良影响,t检验结果显示全茧量、茧层量、蛹体重等指标比对照区均有显著提高,但处理对雌蚕茧层率影响不显著,而雄蚕的茧层率则多数有明显增加。生产中试结果表明,利用最佳处理条件处理蚕卵,张种产茧量比对照平均提高10.86%,茧层量提高15.45%,茧层率和茧层生产效率分别提高5.00%和12.72%,茧丝长和解舒丝长分别增加72.24、76.09 m,解舒率、上车率也均有所提高,光折降低,茧丝纤度略有增加,对茧丝洁净无明显影响。     

Hypoglycemic effects and constituents of the barks of Cyclocarya paliurus and their inhibiting activities to glucosidase and glycogen phosphorylase

The various fractions of the barks of Cyclocarya paliurus were systematically tested for hypoglycemic effects in alloxan-induced diabetic rats. The results showed that the chloroform fraction of the 75% EtOH extract of the barks of this plant exhibited significant blood sugar reducing activity, most of which were significantly higher than that of positive-drug metformin hydrochloride. A new compound, together with nine known compounds, was isolated from the most active fraction. The structure elucidation was based on spectroscopic methods, including two-dimensional NMR experiments (¹H-¹H COSY, HMQC, and HMBC). All of the isolates were evaluated for their α-glycosidase and glycogen phosphorylase inhibitory activities.     

三疣梭子蟹幼体消化酶活力及氨基酸组成的研究

在三疣梭子蟹幼体发育过程中，五种消化酶活力表现出三种变化模式，其中胃蛋白酶和类胰蛋白酶活力呈上升趋势，而且在蚤状幼体Ⅰ期时就较高，淀粉酶活力逐渐减小，纤维素酶和脂肪酶活力极微。氨基酸含量随幼体发育逐渐增加。必需氨基酸中以亮氨酸含量最高，色氨酸含量最低；非必需所基酸中含量最高者为谷氨酸，最低者为胱氨酸。同时单个必需氨基酸含量与必需氨基酸总量的比值（Ａ／Ｅ）在幼体不同发展阶段略有差异，但基本趋于一致。     

Effects of Na/K and Mg/Ca ratios in saline groundwaters on Na-K-ATPase activity, survival and growth of Marsupenaeus japonicus postlarvae

The effects of the Na⁺/K⁺ and Mg²⁺/Ca²⁺ ratios in saline groundwaters on Na⁺-K⁺-ATPase activity, survival and growth of Marsupenaeus japonicus postlarvae were investigated. The results indicate that the Na⁺-K⁺-ATPase activity, survival rate and weight gain of postlarvae were significantly affected by the Na⁺/K⁺ and Mg²⁺/Ca²⁺ ratios (P < 0.05). The Na⁺-K⁺-ATPase activity of postlarvae, in every treatment, changed corresponding to Na⁺/K⁺ and Mg²⁺/Ca²⁺ ratios, and came to a stable level after 24 h. There was a negative relation between Na⁺-K⁺-ATPase activity and Na⁺/K⁺ ratio, while there was a positive relation between Na⁺-K⁺-ATPase activity and Mg²⁺/Ca²⁺ ratio. Compared with seawater (the Na⁺/K⁺ and Mg²⁺/Ca²⁺ ratios are 27.8 and 4.64 respectively), the Na⁺-K⁺-ATPase activity of the Na⁺/K⁺ ratio 30 treatment showed no significant difference, while the Mg²⁺/Ca²⁺ ratio 4.5 treatment showed distinct difference. The survival rates and weight gain of postlarvae increased markedly when the suitable amount of K⁺ and Ca²⁺ was added to test water, and arrived at their maximum in the Na⁺/K⁺ ratio 20-30 or Mg²⁺/Ca²⁺ ratio 4.5 treatment, having no significant difference compared with normal seawater. Therefore, considering the Na⁺/K⁺, Mg²⁺/Ca²⁺ ratios and the absolute concentration of Mg²⁺, Ca²⁺ in the experimental saline groundwaters applied to Marsupenaeus japonicus farming, it should be modulated to around 30, 4.5 and 1312 mg/l, 291 mg/l, respectively.     

Lignans from the heartwood of Streblus asper and their inhibiting activities to hepatitis B virus

Three new lignans, erythro-strebluslignanol (1), threo-7'-methoxyl strebluslignanol (2) and erythro-7'-methoxyl strebluslignanol (3), together with twelve known compounds were isolated from the n-butanol and chloroform fractions of the heartwood of Streblus asper. Their structures were elucidated through extensive spectroscopic methods, including MS and 2D NMR experiments (HMQC and HMBC). The stereochemistry at the chiral center was determined using CD spectra, as well as analysis of coupling constants and optical rotation data, respectively. Primary bioassays showed that 6-hydroxyl-7-methoxyl-coumarin (5) and ursolic acid (10) showed anti-HBV activities, with IC(50) values of 29.60 μM and 89.91 μM for HBsAg at no cytotoxicity, and IC(50) values of 46.41 μM and 97.61 μM for HBeAg at no cytotoxicity, respectively.     

Effects of salinity and pH on ion-transport enzyme activities, survival and growth of Litopenaeus vannamei postlarvae

Effects of the salinity and pH on ion-transport enzyme activities, survival and growth of Litopenaeus vannamei postlarvae were investigated. Shrimp were transferred from salinity 31‰ and pH 8.1 to different salinity levels of 22, 25, 28, 31 (control), and to different pH levels of 7.1, 7.6, 8.1 (control), 8.6 and 9.1. The results showed ion-transport enzyme activities and weight gains of postlarvae were significantly affected by salinity and pH variation, which had no obvious effect on survival rate. The changing salinity affected the activities of total ATPase and Na⁺-K⁺-ATPase notably (F > F_0.05), meanwhile, non-significantly to the activities of V-ATPase, HCO₃⁻-ATPase. Within 48 h of salinity changing, the activities of ATPase, Na⁺-K⁺-ATPase in each treatment group gradually increased with the sampling time and reached their climax at 48 h, and then stabilized, showing negative correlation with salinity. The changing of pH affected greatly the activities of ATPase, Na⁺-K⁺-ATPase, V-ATPase and HCO₃⁻-ATPase (F > F_0.05), the activities of ATPase, Na⁺-K⁺-ATPase in each treatment group (pH = 7.1, 7.6, 8.6, 9.1) showed peak change within 72 h and stabilized afterwards, and the Na⁺-K⁺-ATPase activities came back to the level of the control group; Meanwhile the changing extent of V-ATPase and HCO₃⁻-ATPase activity corresponded with the grads of pH, and these ATPase activities showed negative correlation with pH changing, the activities of V-ATPase, HCO₃⁻-ATPase in postlarvae of each treatment group came to stable level after 24 h. The experiment also indicated the strength order of these ion-transport enzyme activities were as follows: Na⁺-K⁺-ATPase > V-ATPase > HCO₃⁻-ATPase. Na⁺-K⁺-ATPase was the chief undertaker of osmoregulation under the salinity effects, while V-ATPase and HCO₃⁻-ATPase were the chief osmoregulation undertakers under pH changing. In different salinity environment, the contributions of Na⁺-K⁺-ATPase, V-ATPase and HCO₃⁻-ATPase of L. vannamei postlarvae approximately accounted for 62.0-78.0%, 15.9-29.0% and 2.03-4.12% of ATPase activities in total, respectively. Meanwhile, in different pH medium, the contributions of these ATPases approximately accounted for 50.7-67.4%, 21.3-31.8% and 2.15-7.90% of total ATPase activities, respectively. Weight gain of shrimp transferred to salinity 31 (control) and 28‰ was significantly higher than that of shrimp reared at 25 and 22‰, and weight gain of shrimp transferred to pH 8.1 (control) and 8.6 was significantly higher that that of shrimp transferred to pH 7.1, 7.6 and 9.1. It was suggested that during the process of desalting and culturing of postlarvae, the salinity changing should not exceed 3 and pH variety not more than 0.5.