全文获取类型
收费全文 | 541篇 |
免费 | 46篇 |
国内免费 | 84篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 12篇 |
2021年 | 21篇 |
2020年 | 27篇 |
2019年 | 19篇 |
2018年 | 20篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 36篇 |
2014年 | 33篇 |
2013年 | 34篇 |
2012年 | 50篇 |
2011年 | 41篇 |
2010年 | 29篇 |
2009年 | 18篇 |
2008年 | 37篇 |
2007年 | 21篇 |
2006年 | 30篇 |
2005年 | 28篇 |
2004年 | 23篇 |
2003年 | 27篇 |
2002年 | 25篇 |
2001年 | 19篇 |
2000年 | 14篇 |
1999年 | 23篇 |
1998年 | 13篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1985年 | 1篇 |
1982年 | 5篇 |
1969年 | 1篇 |
排序方式: 共有671条查询结果,搜索用时 15 毫秒
21.
Tie J Serizawa Y Oshida S Usami R Yoshida Y 《Human biology; an international record of research》2006,78(2):243-247
The human phosphoglycerate kinase (PGK1) gene is located within Xqll-Xql3 and is closely linked to the androgen receptor gene within a region implicated in a number of X-chromosome-linked urologic disorders. A polymorphism of a TATC short tandem repeat (STR) is present downstream from the PGK1 3' nuclease-sensitive site. We present the PGK1 flanking STR sequence and population genetic data for 190 Japanese males and 83 Japanese females. Ten STR alleles and 29 genotypes were identified in the population. Five alleles--*10, *11, *12, *13, and *14--were common in the Japanese with frequencies greater than 10%. No significant deviations from Hardy-Weinberg equilibrium were established. The power of discrimination was 0.993 for females and 0.819 for males; heterozygosity was 0.759 for females; and the polymorphic information content was 0.936. These data indicate that this STR locus shows a high degree of polymorphism in this Japanese population and may prove to be a useful genetic marker in forensic medicine, in determining the clonality of neoplasms, and potentially in studying predisposition to prostate cancer and other urologic diseases. 相似文献
22.
23.
通过和玉米杂交诱导硬粒小麦单倍体 总被引:5,自引:1,他引:5
硬粒小麦(Triticum durum Desf.)DR147授以超甜玉米(Zea m ays L.) ss 7700的花粉后,在83.4% 的柱头上观察到花粉萌发及花粉管长入胚囊,有9.9% 的子房发生了卵细胞的单受精,1.9% 的子房发生了中央细胞的单受精,32.7% 的子房发生了双受精。尽管双受精后可同时形成胚和胚乳,但胚乳往往发育迟缓,甚至败育。硬粒小麦×玉米形成的杂合子核型高度不稳定,在最初的几次细胞分裂中,来自父本玉米的染色体逐步被排除,最后形成硬粒小麦单倍体胚。在授以玉米花粉4 h 后用100 ppm 2,4-D溶液浸蘸硬粒小麦穗部,可以有效地促进幼胚在缺乏胚乳或胚乳败育情况下的生长和发育。授粉9—13 d 后由533个硬粒小麦子房解剖出25个胚,得胚率为4.7% 。通过幼胚拯救获得11棵正常植株,植株获得率为2.1% 。根尖细胞染色体计数表明,它们为单倍体(2n= 2x= 14)。 相似文献
24.
絮凝基因的克隆和在工业啤酒酵母菌株中表达 总被引:12,自引:1,他引:12
The partial genomic library of Saccharomyce cerevisiae FL189 possessing strong flocculation ability was constructed using Yeast-E.coli shuttle plasmid YCp50 as vector.Recombinant plasmid containing flocculation gene was obtained by screening the growth of transformants on the selective medium and measurement flocculation,designated as pCF1.pCF1 was introduced into industrial yeast strain PJ208-5-15.Six transformants PJ208-5-15-1(pCF1)~PJ208-5-15-6(pCF1)possessing strong flocculation ability were obtained.Th… 相似文献
25.
26.
LeETR1反义基因对番茄的遗传转化 总被引:15,自引:0,他引:15
从番茄果实中提取总RNA,根据GeneBank中LeETR1序列,设计合成特异性引物,利用RT-PCR及技术克隆了LeETR1基因3’端非编码区313bp的cDNA,经酶切图谱和序列分析鉴定无误后,反向插入到植物表达载体pPZP11A中,构建了表达LeETR1反义RNA的双元载体。经农杆菌途径转化番茄品种B1后,通过PCR检测从抗卡那霉素再生植株中筛选到13株阳性植株,Southern blot杂交确证反义基因已经整合到番茄染色体中。对果实乙烯释放的测定结果表明,转基因番茄乙烯释放高峰的出现比对照果实推迟10天,番茄红素的合成受到显抑制,果实不能形成正常的红色。推测LeETR1和番茄的成熟有着密切的关系。 相似文献
27.
PS1基因突变与早发家族性老年痴呆有密切联系.构建pEGFP-C1-PS1以及pEGFP-N2-PS1融合基因表达载体,于HEK293和CHO细胞系中表达PS1/GFP融合蛋白,以GFP绿色荧光作为PS1的亚细胞定位信号,通过SPOTII以及CONFOCAL显微镜进行观察,初步获得PS1全长蛋白在细胞中定位的部分信息,即PS1定位于细胞核膜,细胞质内有不均匀的分布,少量存在于细胞-细胞接触处的细胞膜上. 相似文献
28.
Choline is an essential nutrient for cell survival and proliferation, however, the expression and function of choline transporters have not been well identified in cancer. In this study, we detected the mRNA and protein expression of organic cation transporter OCT3, carnitine/cation transporters OCTN 1 and OCTN2, and choline transporter-like protein CTL1 in human lung adenocarcinoma cell lines A549, H 1299 and SPC-A-1. Their expression pattern was further confirmed in 25 human primary adenocarcinoma tissues. The choline uptake in these cell lines was significantly blocked by CTL1 inhibitor, but only partially inhibited by OCT or OCTN inhibitors. The efficacy of these inhibitors on cell proliferation is closely correlated with their abilities to block choline transport. Under the native expression of these transporters, the total choline uptake was notably blocked by specific PI3K/AKT inhibitors. These results describe the expression of choline transporters and their relevant function in cell proliferation of human lung adenocarcinoma, thus providing a potential "choline-starvation" strategy of cancer interference through targeting choline transporters, especially CTL1. 相似文献
29.
利用染色体消除法获得太谷核不育小麦纯合体 总被引:6,自引:0,他引:6
太谷核不育小麦的育性受单个显性雄性不育基因(Ta1)控制,其不育株总是杂合(Ta1ta1)的,纯合不育株(Ta1Ta1)并不存在。实验以太谷核不育小麦(TriticumaestivumL.)为母本和玉米(ZeamaysL.)杂交,利用杂合子和幼胚细胞分裂过程中父本玉米染色体自发消除的特点,经过激素处理、幼胚拯救和染色体人工加倍,成功地获得了自然界不存在的纯合显性太谷核不育小麦新种质(Ta1Ta1),并利用“玻璃化”超低温保存方法,将这一宝贵新种质长期保存下来。 相似文献
30.
Ken Lin Lin‐Jing Song Jing Ma Tie‐Song Zhang Ding‐Yun You Yong‐Wen He 《Journal of cellular and molecular medicine》2020,24(9):5213-5223
Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral and maxillofacial region. Numerous cancers share ten common traits (“hallmarks”) that govern the transformation of normal cells into cancer cells. Long non‐coding RNAs (lncRNAs) are important factors that contribute to tumorigenesis. However, very little is known about the cooperative relationships between lncRNAs and cancer hallmark‐associated genes in OSCC. Through integrative analysis of cancer hallmarks, somatic mutations, copy number variants (CNVs) and expression, some OSCC‐specific cancer hallmark‐associated genes and lncRNAs are identified. A computational framework to identify gene and lncRNA cooperative regulation pairs (GLCRPs) associated with different cancer hallmarks is developed based on the co‐expression and co‐occurrence of mutations. The distinct and common features of ten cancer hallmarks based on GLCRPs are characterized in OSCC. Cancer hallmark insensitivity to antigrowth signals and self‐sufficiency in growth signals are shared by most GLCRPs in OSCC. Some key GLCRPs participate in many cancer hallmarks in OSCC. Cancer hallmark‐associated GLCRP networks have complex patterns and specific functions in OSCC. Specially, some key GLCRPs are associated with the prognosis of OSCC patients. In summary, we generate a comprehensive landscape of cancer hallmark‐associated GLCRPs that can act as a starting point for future functional explorations, the identification of biomarkers and lncRNA‐based targeted therapy in OSCC. 相似文献