反转

This paper describes an inhibitory effert of GABA on the incorporation of￣3H-TdR into rat anterior pituitary cells in static primary monolayer cultures. The action was antagonizable by picrotoxin.

本实验利用原代细胞培养体系，观察到GABA对大鼠垂体前叶细胞的氚标胸苷（3H－TdR）基础掺入率有明显的抑制性效应，且可被印防己毒素所反转。

Objective:To evaluate the characteristics a nd clinical ap plication of fluid attenuated inversion recovery sequences in MRI of the brain.

目的：通过对头颅液体衰减反转恢复序列的应用研究，了解其特点及临床价值。

Transgenic tobacco plants were obtained through screening with kanamycin. The transgenic tobacco plants could delay TMV infection for about 25 days compared with non-transgenic tobacco plants. Pokeweed antiviral protein Ⅱ is expressed with high level in summer leaves. The expression of PAPⅡ is regulated by season. The total RNA was extracted from pokeweed (Phytolacca americana L.) leaves in summer using the method of TRIzol and used as template to amplify the PAPⅡ gene by RT-PCR and then the gene was cloned into E. coli expression vector and secreted expression pPIC9K vector. The two vectors with PAPⅡ gene were then transferred into E. coli strain BL21 (DE3)-plysS and Pachia pastoris GS115 strain respectively. The specific protein was produced induced by IPTG and methanol.

由于美洲商陆抗病毒蛋白Ⅱ是一个受季节调控表达的蛋白，本实验以美洲商陆夏季叶片为材料，通过对其总RNA的提取、反转录、并用PAPⅡ的特异引物进行PCR扩增，对PAPⅡ进行了基因克隆、序列分析，结果扩增出来的PAPⅡ基因与已经报道的序列同源性是99.9％，然后将该基因构建到原核、真核表达载体上，分别转化了大肠杆菌和毕赤酵母并对它们进行了诱导表达，在两个表达系统中均获得了有活性的PAPⅡ表达蛋白，体外生物测定表明表达的蛋白均具有抑制病毒的活性，PAPⅡ基因在酵母中还没有表达的报道，这为获得具活性PAPⅡ蛋白提供了一种简便可行的方法。

The transgenic tobacco plants could delay TMV infection for about 25 days compared with non-transgenic tobacco plants.Pokeweed antiviral protein II is expressed with high level in summer leaves. The expression of PAPII is regulated by season. The total RNA was extracted from pokeweed (Phytolacca americana L.) leaves in summer using the method of TRIzol and used as template to amplify the PAPII gene by RT-PCR and then the gene was cloned into E.coli expression vector and secreted expression pPIC9K vector. The two vectors with PAPII gene were then transferred into E.coli strain BL21 (DE3)-plysS and Pachia pastor is GS115 strain respectively. The specific protein was produced induced by IPTG and methanol.

由于美洲商陆抗病毒蛋白Ⅱ是一个受季节调控表达的蛋白，本实验以美洲商陆夏季叶片为材料，通过对其总RNA的提取、反转录、并用PAPⅡ的特异引物进行PCR扩增，对PAPⅡ进行了基因克隆、序列分析，结果扩增出来的PAPⅡ基因与已经报道的序列同源性是99.9％，然后将该基因构建到原核、真核表达载体上，分别转化了大肠杆菌和毕赤酵母并对它们进行了诱导表达，在两个表达系统中均获得了有活性的PAPⅡ表达蛋白，体外生物测定表明表达的蛋白均具有抑制病毒的活性，PAPⅡ基因在酵母中还没有表达的报道，这为获得具活性PAPⅡ蛋白提供了一种简便可行的方法。

1The polarizability of a polymeric molecule with a polaron can be reversed by absorbing one photon.

具有极化子的聚合物分子可通过吸收一个光子而实现极化反转。

Design of eccentric rotating conjugate cams paper-transferring mechanism ;2. On the basis of the principle of TYM 750 Die Cutting and Foilstamping Press,the mathematical model for the paper-transferring mechanism was constructed.

根据TYM 750烫印模切机递纸机构的工作原理，构建递纸机构的数学分析模型，按照递纸吸嘴的运动轨迹，求出递纸机构中凸轮从动杆的运动规律，利用反转法得到凸轮的廓线。

Also, the voltage on the primary winding reverses direction during the operation of the circuit but this too, does not have any effect on the oscillations.

此外，太初级绕组电压反转方向，在电路的运作，但是这一点，没有任何振荡的影响。

With the proper coordinate system,the movement of up cut and down cut rotary blades can be incorporated in one equation,but two kinds of blades work in different angular ranges.

通过建立适当的坐标系，把正、反转旋耕刀的运动统一起来，用同一个方程表示，二者只是在不同的切土范围内工作。

In order to clone the VIP gene in the gastrointestinal tract from beijing duck, one pair of specific primers to VIP gene was designed and synthesized according to the chick sequence (X80906). Encoding VIP cDNA fragments were amplified by RT-PCR from the total RNA in the Proventriculus, the Duodenum and the Jejunum of Beijing duck. Their PCR products were ligated into pGEM-T easy vector, which was transformed into E. coil JM109. Positive bacteria clones were screened and identified by PCR method and digested with the double restriction enzyme EcoRⅠ. The sequence of VIP gene fragment was also determined and analyzed.

为从北京鸭胃肠道中扩增血管活性肠肽基因，根据鸡VIP基因（GenBank登录号X80906），设计了一对简并引物，从北京鸭腺胃、十二指肠和空肠提取总RNA，通过反转录－聚合酶链反应扩增，将从腺胃、十二指肠和空肠中扩增出的产物克隆到pGEM-Teasy载体上，导入大肠杆菌JM109，阳性克隆经双酶切鉴定后测序，将测序结果与鸡和鹅（GenBank登录号为DQ023161）的VIP基因进行同源性比较。

The results indicated that the passive films showed a distribution of multi-layer structure and properties of p-type semiconducting in the conditions of quiescence.

结果表明，静态条件下， 0Cr13Ni5Mo和1Cr18Ni9Ti不锈钢均发生了钝化，钝化膜呈多层结构分布；空化条件下，钝化膜的稳定性降低，半导特性发生反转。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。