全文获取类型
收费全文 | 195篇 |
免费 | 13篇 |
国内免费 | 15篇 |
专业分类
223篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 20篇 |
2012年 | 16篇 |
2011年 | 9篇 |
2010年 | 13篇 |
2009年 | 16篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 1篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 0 毫秒
91.
92.
Cheryl Sorenson Jamison Paul L. Jamison Robert J. Meier 《American journal of physical anthropology》1994,94(3):409-419
Dermatoglyphic ridge counts of the prints of 59 rhesus monkeys (Macaca mulatta) whose mothers had been treated with injections of testosterone during their pregnancies were studied to determine the effect of the day the hormone began to be administered, the amount of hormone administered, and the number of days of hormone administration upon the dermatoglyphic variation of the offspring. Of the three hormone variables, only the day of beginning administration (STARTDAY) was significantly associated with dermatoglyphic variation, and its positive significance was demonstrated with the ridge counts of Area I on both the left and right hand, Area II of the left hand, and the total ridge counts of both hands. These results are discussed within the context of the timing of the dermatoglyphic window, and the differences in the findings between the monkey and earlier human studies are addressed. © 1994 Wiley-Liss, Inc. 相似文献
93.
Study of the O.H. 7 hand was based primarily on morphological comparisons with a large series of hand skeletons of extant hominoid primates. Most of the hand elements are fragmentary or have missing epiphyses and only comparisons based on qualitative morphological observations are possible. The distal phalanges are complete, however, and were analyzed metrically utilizing univariate and multivariate statistical techniques. To compensate for size differences among the Hominoidea a number of size adjustments were employed. None of the adjustments were totally satisfactory from theoretical and practical standpoints and none completely eliminated the influence of size. There is no entirely satisfactory procedure to eliminate size and it is advisable to use several techniques that are not closely related, to compare the results and interpret them with caution. In certain features the wrist and fingers resemble those of African apes; in others they are more like modern human hands; in still others they are unique. The scaphoid and the proximal articular surface of the trapezium retain ape-like features, as do the proximal and middle phalanges. The pollical carpometacarpal joint and the distal phalanges are closer in morphology to those of modern humans. The scaphoid, proximal phalanges and middle phalanges of rays II-V indicate a hand capable of a strong power grip. A number of features of the thumb and the distal phalanges suggest that the O.H. 7 individual was capable of more precise manipulation that extant apes. FLK NN-A, a first distal phalanx, does not closely resemble the first distal phalanx of any of the living Hominoidea. Multivariate distance analysis indicates, however, that it is closest in overall morphology to the pollical distal phalanx of modern humans. In some features not included in the metric analysis, FLK NN-A also resembles the hallucial distal phalanx of modern humans. 相似文献
94.
Hendershot TJ Liu H Clouthier DE Shepherd IT Coppola E Studer M Firulli AB Pittman DL Howard MJ 《Developmental biology》2008,319(2):179-191
Neural crest-derived structures that depend critically upon expression of the basic helix-loop-helix DNA binding protein Hand2 for normal development include craniofacial cartilage and bone, the outflow tract of the heart, cardiac cushion, and noradrenergic sympathetic ganglion neurons. Loss of Hand2 is embryonic lethal by E9.5, obviating a genetic analysis of its in-vivo function. We have overcome this difficulty by specific deletion of Hand2 in neural crest-derived cells by crossing our line of floxed Hand2 mice with Wnt1-Cre transgenic mice. Our analysis of Hand2 knock-out in neural crest-derived cells reveals effects on development in all neural crest-derived structures where Hand2 is expressed. In the autonomic nervous system, conditional disruption of Hand2 results in a significant and progressive loss of neurons as well as a significant loss of TH expression. Hand2 affects generation of the neural precursor pool of cells by affecting both the proliferative capacity of the progenitors as well as affecting expression of Phox2a and Gata3, DNA binding proteins important for the cell autonomous development of noradrenergic neurons. Our data suggest that Hand2 is a multifunctional DNA binding protein affecting differentiation and cell type-specific gene expression in neural crest-derived noradrenergic sympathetic ganglion neurons. Hand2 has a pivotal function in a non-linear cross-regulatory network of DNA binding proteins that affect cell autonomous control of differentiation and cell type-specific gene expression. 相似文献
95.
The region with the potential to form the heart has traditionally been called the heart field. This region can be approximated by, but is not identical to, the expression domain of the early cardiac gene Nkx2.5. The region expressing Nkx2.5 does not change in size, although there are major shape changes and a subdivision of the region into non-myogenic and myogenic lineages. Using a variety of embryo manipulations, we have sought to determine whether cellular interactions could change the size of the initial Nkx2.5-expressing region and thus change the size of the heart. We have shown that if the heart is isolated from the dorsal half of the embryo, the volume of tissue expressing myocardial differentiation markers increases, indicating that signals restricting the size of the heart come from the dorsal side. Despite the change in myocardial volume, the non-myogenic heart lineages are still present. The ability of dorsal tissues to restrict the size of the heart is further demonstrated by fusing two Xenopus embryos shortly after gastrulation, generating twinned embryos where the heart of one embryo would develop adjacent to different tissues of the second embryo. The final size of the differentiated heart was markedly reduced if it developed in close proximity to the dorso-anterior surface of the head but not if it developed adjacent to the flank or belly. In all cases, the manipulations that restricted the size of the myocardium also restricted the expression of Nkx2.5 and GATA-4, both key regulatory genes in the cardiogenic pathway. These results provide evidence for a model in which signals from dorso-anterior tissues restrict the size of the heart after gastrulation but before neural fold closure. 相似文献
96.
Jiayu Wang Jiajing Liu Fanghao Fang Jiajin Wu Tianjiao Ji Yuying Yang Ling Liu Chongshan Li Wanju Zhang Xi Zhang Zheng Teng 《中国病毒学》2022,37(2):177-186
Coxsackievirus A10 (CVA10) is one of the major causative agents of hand, foot and mouth disease (HFMD). To investigate the epidemiological characteristics as well as genetic features of CVA10 currently circulating in Shanghai, China, we collected a total of 9,952 sporadic HFMD cases from January 2016 to December 2020. In the past five years, CVA10 was the fourth prevalent causatives associated with HFMD in Shanghai and the overall positive rate was 2.78%. The annual distribution experienced significant fluctuations over the past five years. In addition to entire VP1 sequencing, complete genome sequencing and recombination analysis of CVA10 isolates in Shanghai were further performed. A total of 64 near complete genomes and 11 entire VP1 sequences in this study combined with reference sequences publicly available were integrated into phylogenetic analysis. The CVA10 sequences in this study mainly belonged to genogroup C and presented 91%-100% nucleotide identity with other Chinese isolates based on VP1 region. For the first time, our study reported the appearance of CVA10 genogroup D in Chinese mainland, which had led to large-scale outbreaks in Europe previously. The recombination analysis showed the recombination break point located between 5,100 nt and 6,700 nt, which suggesting intertypic recombination with CVA16 genogroup D. To conclusion, CVA10 genogroup C was the predominant genogroup in Shanghai during 2016-2020. CVA10 recombinant genogroup D was firstly reported in circulating in Chinese mainland. Continuous surveillance is needed to better understand the evolution relationships and transmission pathways of CVA10 to help to guide disease control and prevention. 相似文献
97.
Nadia Corp Hitoshige Hayaki Takahisa Matsusaka Shiho Fujita Kazuhiko Hosaka Nobuyuki Kutsukake Michio Nakamura Miho Nakamura Hitonaru Nishie Masaki Shimada Koichiro Zamma William Wallauer Toshisada Nishida 《Primates; journal of primatology》2009,50(2):184-189
In 1998, four chimpanzees in the Mahale Mountains National Park, Tanzania, were observed wiping their mouths with non-detached
leaves or stalks of grass, or rubbing their mouths with a tree trunk or branch, especially while eating lemons. The number
of mouth-wiping/rubbing individuals increased to 18 in 1999. By 2005, 29 chimpanzees were documented wiping/rubbing their
muzzles in this way. Although it is difficult to determine whether the chimpanzees acquired this behavior as a result of trial
and error or social learning, the fact that chimpanzees at other sites perform this behavior with detached leaves or leafy
twigs much more often than with intact items suggests the possibility that cleaning with intact plant parts at Mahale spread
via social learning. 相似文献
98.
在湖南省娄底地区调查了汉族湘语族群507例(男269例、女238例)高中学生的7项不对称行为特征(扣手、利手、叠臂、叠腿、利足、起步类型和优势眼)。研究结果显示:1)湘语族群叠臂与起步类型L型率高于R型率, 其余5项均R型率高于L型率。2)湘语族群利手、叠臂、利足出现率存在性别间差异, 其余4项出现率均不存在性别间差异。3)在已发表的资料中, 湘语族群扣手和起步类型右型率中等偏高, 利手右型率处于中等水平, 叠臂和叠腿右型率低,利足和优势眼右型率高。4)主成分分析结果显示, 汉族各族群不对称行为特征有一定的共性, 相对接近于中国北亚类型族群, 而与南亚类型族群差距较大。中国族群间不对称行为特征的差异, 主要反映在叠臂率差异、利足率差异。 相似文献
99.
100.
布依族人手的应用人类学研究 总被引:1,自引:0,他引:1
本文探讨了布依族人手的形态特征, 为体质人类学积累资料和整形外科、机械设备、工具制造、手防护用具等设计提供形态学依据。采用国际通用的手部测量方法, 测量了312名(男153,女159) 布依族人手44项指标。所测数据均为男性大于女性(P<0.01), 测量项目右侧大于左侧的男性为75%, 女性为81.82%; 手形厚度、围度、长度和宽度差异均具有统计学意义(P<0.05或P<0.01); 掌指数男性为96.56、女性为93.84, 手指数男性为46.12、女性为45.66。结果表明, 布依族人手形态具有左右侧非对称性和明显的性别差异; 手型呈短宽型, 指型呈短粗型。 相似文献