必需的

And there are essential genes for sperm formation on the Y chromosome.

生殖细胞的性别主要是由生殖腺中体细胞的微环境决定的。Y染色体上存在精子形成所必需的基因。

Complete and articulated fossils such as these suggest that the lakes present at that time were fairly deep, to allow the anoxic conditions required for preservation.

象这些完整的和有关节的化石使我们了解到那个时候的湖泊很深，能有这样的保存缺氧条件是必需的。

Marco Centanni, M.D., Lucilla Gargano, M.D., Gianluca Canettieri, M.D., Nicola iceconti, M.D., Antonella Franchi, M.D., Gianfranco Delle Fae, M.D., and Bruno Annibale, M.D

讨论：伴有泌酸分泌损伤的病人对于甲状腺素的需求增加，表明正常的胃酸分泌对于口服甲状腺素的吸收是必需的。

In structure-function analysis of AdM, it showed that the carboxy terminal 22～52 amino acide fragment is important and necessary for the expression of the cardiovascular activity of AdM.

应用人工合成的AdM的不同片段给麻醉大鼠侧脑室注射，发现AdM的22～52氨基酸片段是维持其活性所必需的。

"Due to the displaced cardiotoxic manifestation, functional monitoring in close connection with anthracycline administration appears to be a poorly effective method, while later monitoring is essential," write Benny V.

由于会出现迟发的心脏毒性，因此在使用anthracycline后，立即进行心功能监测，看来是一种效率很低的方法，稍后时间的监测是必需的。

"Due to the displaced cardiotoxic manifestation, functional monitoring in close connection with anthracycline administration appears to be a poorly effective method, while later monitoring is essential," write Benny V.

由於会出现迟发的心脏毒性，因此在使用anthracycline后，立即进行心功能监测，看来是一种效率很低的方法，稍后时间的监测是必需的。

Direct cytolytic function is essential for TEM-mediated GVL, but that GVL is retained when killing via FasL, TNF-alpha, TRAIL and perforin are individually impaired.

直接的细胞溶解作用是TEM介导的移植物抗白血病所必需的，但是移植物抗白血病效应在FasL， TNF-alpha， TRAIL和穿孔素逐一受损的时候仍然存在。

Two polysilicon sensing structures each contain a quality mass, which is electrostatically driven to resonance.

陀螺仪包含两个多晶硅传感结构，每个都含有在静电激励下而谐振的质量块，在有角速度的期间，谐振的速度是产生哥氏力所必需的。

To define further the fragments regulating gene expression, the Lcn5 promoter was examined in transgenic mice and immortalized epididymal cell lines.

经过一系列的缺失试验后，发现在转基因小鼠中Lcn5基因1.8 kb长的启动子片断对于基因的组织特异性和区域特异性表达是必需的。

A firstness, a twfirstss, a Number 3ness these applies to any class of objects orsetting a tcapable - is itself far since innate.

她们还表达抽象的数字概念，如可表达任何一类物品并且是在做比摆桌子有更高数学要求的任何事时都必需的一、二、三意识，远远否则天生就具备的。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐