脊髓苯环立啶受体的心血管效应与去甲肾上腺素能系统

本文应用受体阻断、高效液相,6-OHDA 化学损毁神经末梢和放射自显影等多学科技术方法,探讨脊髓苯环立啶受体的心血管效应与去甲肾上腺素能神经系统的关系。结果表明,哌唑嗪、育亨宾均可对抗 ith PCP 的降压和减慢心率作用,ith PCP 产生降压和减慢心率作用时,脊髓脑脊液内 MHPG 的含量升高;用6-OHDA 损毁脊髓 NA 能神经末梢后,ith PCP的降压和减慢心率作用大为减弱,脊髓 PCP 受体密度亦同时大为降低。可以认为,脊髓内有 PCP 受体分布于 NA 能神经末梢上,促进 NA 释放或抑制 NA 重摄取,可能是脊髓 PCP 受体产生心血管抑制效应的重要机理。     

日本血吸虫尾蚴的组织化学及扫描电镜观察

日本血吸虫尾蚴具有一个头腺、2对前钻腺及3对后钻腺,其解剖学位置、构造、化学成分及功能均有区别。钻腺分泌物含有多糖酶及蛋白酶。尾蚴的前端系特化的头器结构,它具有半月形嵴、钻腺开口及乳突。     

猴头菇对小鼠抗疲劳作用的实验研究

分别以猴头菇干粉（猴头菇Ⅰ组）和猴头菇浸出液（猴头菇Ⅱ组）饲喂小鼠,观察猴头菇对小鼠血清乳酸脱氢酶（ＬＤＨ）活力、血乳酸、血清尿素氮（ＢＵＮ）、肝糖原、肌糖原含量及运动耐力的影响。结果表明：实验６０ｄ后,猴头菇Ⅰ、Ⅱ组ＬＤＨ活力、肝糖原及肌糖原含量明显高于对照组（Ｐ＜０．０５或Ｐ＜０．０１）;运动后血乳酸的水平和ＢＵＮ的增量明显低于对照组（Ｐ＜０．０５或Ｐ＜０．０１）;运动后血乳酸消除速率显著高于对照组（Ｐ＜０．０５）;在运动耐力测定时在水中淹死的时间比对照组长得多（Ｐ＜０．０５）。提示：猴头菇具有明显的增强运动能力和解除疲劳的作用。     

盐磷胁迫对木麻黄和台湾相思种子萌发及幼苗生长的影响

恶劣环境下,人工海防林因面临养分胁迫而经营困难。为探讨盐、磷胁迫对主要海防林树种木麻黄和台湾相思种子萌发及生长的影响,该研究分别用不同浓度的NaCl(盐)和KH₂PO₄(磷)溶液处理种子和浇灌幼苗,测定种子萌发和幼苗生长指标。结果表明：(1)高盐胁迫显著抑制种子萌发,对幼苗生长有一定影响,但两种植物影响程度不同;台湾相思种子萌发耐盐性高于木麻黄,前者相对盐害率最大值为23.03%,后者为89.15%;随着盐浓度增加,木麻黄和台湾相思种子的发芽率、发芽势、发芽指数和活力指数均降低,对应最大值分别为38.70%、34.67%、18.70、0.055和76.67%、62.22%、48.46、6.11。(2)两种植物的株高和根长随盐浓度增加而降低,木麻黄和台湾相思株高分别为12.29～6.01 mm和48.27～17.33 mm,根长分别为8.57～1.45 mm和33.41～5.88 mm;台湾相思根、茎、叶生物量及根冠比均随盐浓度的增加逐渐减小,木麻黄各处理差异较小。(3)台湾相思的种子和幼苗较木麻黄更耐低磷环境,二者最适磷浓度存在差异;木麻黄种...     

靖西长喙木兰，广西木兰科一新种（英文）

描述了产自广西木兰科一新种：靖西长喙木兰(Lirianthe jingxiensis Y. H. Tong&N. H. Xia)。本种形态上与绢毛木兰[L. albosericea(Chun&C. H. Tsoong)N. H. Xia&C. Y. Wu]接近,但区别在于该种植株较矮,幼枝、叶柄和幼叶被黄棕色绢毛,叶柄较宽,叶片较宽,倒卵形或倒卵状椭圆形,先端钝或短渐尖,花被片较大,心皮数目较多,被黄棕色绢毛。     

中国麻螽属四新种记述（直翅目：露螽科）

本文记述麻螽属４新种,海南麻螽Ｔａｐｅｉｎａｈａｉｎａｎｅｎｓｉｓｓｐ．ｎｏｖ细齿麻螽Ｔａｐｅｉｎａｓｐｉｎｉｃａｕｄａｔａｓｐ．ｎｏｖ四齿麻螽Ｔａｐｅｉｎａｑｕａｄｒｉｄｅｎｓｓｐ．ｎｏｖ。和简麻螽Ｔａｐｉｅｎａｓｉｍｐｌｉｃｉｓｓｐ．ｎｏｖ．新种模式标本均保存在中国科学院上海昆虫研究所。     

A ketoreductase gene from Streptomyces mycarofaciens 1748 DNA involved in biosynthesis of a spore pigment

An efficient plasmid transformation system forS. mycarofaciens 1748 has been established. In order to determine the function of MKR gene in S.mycarofaciens 1748, the gene disruption experiment was carried out. For this purpose the plasmid pKC1139 was used. A recombinant strain with white spore appeared, in contrast to the grey-colour spore of S.myarofaciens 1748. This suggested that homologous recombination between plasmidborne MKR gene sequence and the chromosome of S.mycarofaciens 1748 had occurred. A Southern hybridization experiment using a-³²P-labelled MKR gene as probe indicated that the desired integration event had occurred in the recombinant. The result of gene disruption showed that the alteration of this gene in the chromosome of S.mycarofaciens 1748 made sporulating colonies remain white instead of taking on the typical grey colour of sporulating wild type colonies, suggesting that MKR gene is involved in the biosynthesis of a spore pigment. The recombinant strain was incubated with fermentation medium optimised for midecamycin production. A TLC assay showed that the recombinant strain produced midecamycin in quantities comparable to that ofS. mycarofaciens 1748. A pCN8B12 was a clone from genomic library of midecamycin producing strain which contained a 28-kb DNA insert. The 28-kb DNA fragment contained act I-homologous and act III-homologous regions. he PKS (act I-homologous) and MKR (act III-homologous) genes that define spore pigment of midecamycin producing strain were Jocalized by restriction endonuclease digestion with pCN8B12, indicating that they are separated by about 10 kb DNA. The polyketide synthase gene cluster of simila; organization has not been reported yet. Project supported by the National Natural Science Foundation of China.     

蓖麻蚕蛹卵巢发育过程中亚细胞组分核酸和蛋白质的代谢与脑激素的影响

在20℃条件下,蓖麻蚕蛹期发育需14天,接近发育完成的卵巢中各亚细胞组分中DNA、RNA和蛋白质含量迅速增长。经手术去脑后的蓖麻蚕无脑蛹卵巢不发育,其卵巢中上述成分的含量皆处于蛹早期水平。经脑激素处理后的无脑蛹卵巢即可迅速发育,在处理后18—20天,卵巢发育可接近正常水平,但较晚。在电镜下观察到的游离多核糖体呈二到七聚体,其紫外光谱特性为A260/A280=1.70;A240/A280=1.27。将脑激素注射到无脑蛹中去,可促使卵巢中游离多核糖体含量的增加。     

拟除虫菊酯类农药对茶树害虫的生物活性与残留降解

本文报道了溴氰菊酯、联苯菊酯、氯氰菊酯、顺式氯氰菊酯、杀灭菊酯、功夫菊酯和二氯苯醚菊酯等七种拟除虫菊酯类农药对茶树主要害虫的杀虫效果和在茶树叶片上的降解动态试验结果.上述七种拟除虫菊酯类农药对鳞翅目茶树害虫的幼虫都具有极高的毒力,但对其他害虫的活性谱则表现有差异.它们在茶树芽梢上的降解速率常数为0.20—0.28天^-1,在茶树上的半衰期为2.5—3.5天,明显较有机磷农药稳定.在影响降解的因素中,挥发、热分解、雨水淋洗的作用不大,由茶梢生长稀释所起的作用较为明显.鲜叶中的农药残留在加工过程中的降解率为15—45%,平均20%,远低于有机磷农药.成茶中的残留农药在泡茶过程中由于他们的低水溶性,因此浸出率很低,一般仅有1—4.5%.