全文获取类型
收费全文 | 5720篇 |
免费 | 162篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 110篇 |
妇产科学 | 739篇 |
基础医学 | 680篇 |
口腔科学 | 10篇 |
临床医学 | 294篇 |
内科学 | 419篇 |
皮肤病学 | 520篇 |
神经病学 | 590篇 |
特种医学 | 111篇 |
外科学 | 334篇 |
综合类 | 315篇 |
预防医学 | 1275篇 |
眼科学 | 1篇 |
药学 | 353篇 |
中国医学 | 71篇 |
肿瘤学 | 71篇 |
出版年
2023年 | 69篇 |
2022年 | 160篇 |
2021年 | 208篇 |
2020年 | 297篇 |
2019年 | 284篇 |
2018年 | 232篇 |
2017年 | 281篇 |
2016年 | 229篇 |
2015年 | 137篇 |
2014年 | 303篇 |
2013年 | 410篇 |
2012年 | 226篇 |
2011年 | 279篇 |
2010年 | 214篇 |
2009年 | 288篇 |
2008年 | 293篇 |
2007年 | 307篇 |
2006年 | 257篇 |
2005年 | 148篇 |
2004年 | 141篇 |
2003年 | 102篇 |
2002年 | 99篇 |
2001年 | 74篇 |
2000年 | 65篇 |
1999年 | 52篇 |
1998年 | 53篇 |
1997年 | 35篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 24篇 |
1993年 | 26篇 |
1992年 | 36篇 |
1991年 | 24篇 |
1990年 | 18篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 14篇 |
1985年 | 44篇 |
1984年 | 41篇 |
1983年 | 32篇 |
1982年 | 28篇 |
1981年 | 33篇 |
1980年 | 39篇 |
1979年 | 27篇 |
1978年 | 19篇 |
1977年 | 22篇 |
1976年 | 26篇 |
1975年 | 16篇 |
1973年 | 19篇 |
排序方式: 共有5896条查询结果,搜索用时 15 毫秒
51.
大学生性行为及性道德观发展研究 总被引:6,自引:0,他引:6
目的 了解当代大学生性行为及性道德观念的发展变化。方法 自制问卷,对全国9所高校的2000余名大学生进行调查,并用SPSS10.0对结果进行统计处理。结果 大学生性交行为发生率呈逐年上升趋势,且随年级上升而增加;大学生认可性交行为道德观的5个雏度,但各年级之间有差异;大学生边缘性行为和独自性行为发生率随年级显著上升,认可度也随年级增加而上升;大学生对同性性接触基本持排斥态度,但排斥态度则趋于下降。结论 大学生性行为和性道德随年级上升而明显变化,应加强学校教育和引导。 相似文献
52.
Summary We isolated heterothallic strains from a homothallic strain of S. exiguus by mutagenization with UV or ethylmethanesulfonate (EMS). A gene, not linked to the mating-type locus, was found to control homothallism in the yeast, as in S. cerevisiae. Pheromone of S. exiguus (se pheromone) induced formation of large pear-shaped cells (shmooing) in a strains of S. exiguus, S. cerevisiae, and S. kluyveri, and sexual agglutinability of an inducible a strain of S. cerevisiae. se Pheromone is a peptidyl substance a little different from pheromone of S. cerevisiae. a Pheromone of S. exiguus acts only on a cells of S. exiguus. Contrary to the above results, neither sexual agglutination nor zygote formation occurred among these three Saccharomyces yeasts. 相似文献
53.
Summary Normal sexual development is the consequence of three sequential interrelated processes: establishment of genetic, gonadal and somatic sex. It is the terminal phase of sexual differentiation-the translation of gonadal into somatic sex, which is governed by the presence or absence of both testosterone and Müllerian-inhibiting hormone and of dihydrotestosterone, which is formed in its respective target tissues. Thus, despite a testis, somatic male sexual differentiation will proceed to a normal male phenotype only if all three hormones are synthesized and act during a critical period of uterine development. Many clinically distinct syndromes are the results of abnormalities in the synthesis or action of the above-mentioned hormones; these syndromes are described in detail. In contrast to male somatic differentiation, female somatic development is independent of these hormones.
Abkürzungen DHT 5-Dihydrotestosteron - HY-Antigen Histocompatibilitätsantigen-Y - MIH Müllerian-Inhibiting-Hormon - SSW Schwangerschaftswoche Die eigenen Untersuchungen wurden durch die Deutsche Forschungsgemeinschaft Schw 168/5–7 unterstützt 相似文献
Abkürzungen DHT 5-Dihydrotestosteron - HY-Antigen Histocompatibilitätsantigen-Y - MIH Müllerian-Inhibiting-Hormon - SSW Schwangerschaftswoche Die eigenen Untersuchungen wurden durch die Deutsche Forschungsgemeinschaft Schw 168/5–7 unterstützt 相似文献
54.
Naturally cycling female hamsters were run in a T-maze to determine their preference for exposure to an intact male enclosed in one goal box or a castrated male in the other goal box; physical contact with the goal animals was prevented. All animals preferred the intact male, but only on estrous days, and the preference was maintained even when no differential stimuli reached the choice point from the goal animals. The preference is interpreted as demonstrating that non-copulatory exposure to stimuli emanating from an intact male is reinforcing for an estrous female. 相似文献
55.
Sprague-Dawley rats were ovariectomized and received bilateral sham, electrolytic or kainic acid lesions of the septum. Kainic acid lesions are purported to destroy cell bodies while not appreciably damaging fibers of passage or afferent terminals. Following priming with estradiol benzoate (EB), animals received three consecutive tests of lordosis and rejection behavior. Animals also received six tests of reactivity; one prior to each EB priming regimen and one following each lordosis and rejection test. Reactivity measures included resistance to capture and magnitude and quantity of startle responses. Electrolytic and kainic acid lesions were equivalent in facilitating lordosis. Although both lesions also increased rejection frequency, kainic acid effects were transient and markedly smaller by 60–80%. Reactivity data generally demonstrated significantly higher scores for kainic acid and electrolytic lesions groups and apparently time-dependent decreases in these scores. The results suggest that rejection behavior is not necessarily correlated with either lordosis or hyperreactivity. 相似文献
56.
Previously, our laboratory has shown that androgen receptors in the medial preoptic area (MPOA) and ventromedial nucleus (VMN) are necessary for copulation in male rats. The present study examined whether these receptors are required for other sociosexual behaviors. In Experiment 1, different regions of the VMN were implanted with the antiandrogen hydroxyflutamide (OHF). We found that implants located in anterodorsal portions of the VMN were more effective at inhibiting the restoration of copulation than implants in the posteroventral VMN. In Experiment 2, a second set of male rats was pretested for copulation and other sociosexual behaviors and was castrated. Experimental animals then received Silastic capsules filled with testosterone (T) plus intracranial (IC) implants filled with OHF to selectively block androgen receptors in either the MPOA or VMN. We found that androgen receptor blockade in the MPOA inhibited the restoration of copulation but had no effect on other sociosexual behaviors. OHF directed at the VMN inhibited the restoration of copulation and 50-kHz vocalizations but had no effect on scent marking. Two tests were used to assay sexual motivation: partner preference and conditioned place preference (CPP). Both methods revealed impairments in sexual motivation in the VMN group but not in animals receiving OHF in the MPOA. Taken together, these data suggest that androgen receptors in the MPOA are essential for copulatory performance, while androgen receptors in the VMN are important for copulation, sexual motivation, and androgen-dependent vocalizations. 相似文献
57.
目的探讨性分化发育不良患者SRY基因的作用及其临床意义.方法选择在我院遗传室咨询的性分化发育不良患者50例,在染色体核型分析的基础上,应用聚合酶链(PCR)技术对每例患者检测SRY基因,应用DNA序列分析技术对6例性染色体XX或XY而SRY( )的女性患者和2例染色体为46,XY、SRY( )睾丸发育不良的男性患者,进行了SRY基因序列分析.结果 (1)1例46,XX女性SRY( ),1例46,XX男性SRY(-),1例46,XX/46,XY女性和1例核型为47,XXY男性SRY( ),在46,XY患者中女性11例,男性6例SRY( ).(2)1例46,XX女性SRY基因存在点突变,1例46,XY女性患者SRY基因序列存在点突变和移码突变.结论对性分化发育不良患者进行SRY检测及其基因分析,不仅有利于为该类患者寻找病因,而且有利于指导治疗. 相似文献
58.
Hamster pups were tested for an odor preference every day from 1-16 days of age with shavings from their home cage and with clean wood shavings. The hamster pups showed a clear preference for their home cage shavings by 8 days of age. They were then tested for preferences with other odor combinations. Tests for preference with other odor pairs indicate that this preference is due to a change in the hamsters rather than a change in the stimulus. In these tests the hamster pups did not demonstrate a preference for their home shavings over shavings in which a nonlactating female had lived. Further tests will have to be done to determine how specific the hamster pup's olfactory preferences are. 相似文献
59.
Rachael Goodman-Williams Rebecca Campbell Dhruv B. Sharma Steven J. Pierce Hannah Feeney Giannina Fehler-Cabral 《Journal of trauma & dissociation》2019,20(3):288-303
ABSTRACTHundreds of thousands of previously untested sexual assault kits (SAKs) have been uncovered in police property storage facilities across the United States, representing a national failure in institutional response to sexual assault. Faced with this discovery, jurisdictions must now decide if and how they should test these kits. Some stakeholders have suggested prioritizing kits for testing by victim, offender, or assault characteristics, based on the belief that these characteristics can predict the likely utility of DNA testing. However, little research has examined the empirical merits of such prioritization. To address this gap in the literature and inform SAK testing policies, we randomly sampled 900 previously untested SAKs from Detroit, MI. The sampled SAKs were submitted for DNA testing, and eligible DNA profiles were entered into Combined DNA Index System (CODIS), the federal DNA database. Police records associated with each SAK were coded for victim, offender, and assault characteristics, and logistic regression analyses were conducted to test whether these characteristics predict which SAKs yield DNA profiles that match (“hit”) to other criminal offenses in CODIS. Testing this sample of previously-untested SAKs produced a substantial number of CODIS hits, but few of the tested variables were significant predictors of CODIS hit rate. These findings suggest that testing all previously-unsubmitted kits may generate information that is useful to the criminal justice system, while also potentially addressing the institutional betrayal victims experienced when their kits were ignored. 相似文献
60.
本文对60名女性海洛因依赖者与54名健康女性的月经、生育等女性生理机能和性心理及性行为进行调查分析。发现女性海洛因依赖者月经异常率为95.0%,显著高于对照组6.8%(P<0.001);海洛因对性欲和性行为影响明显,吸注海洛因成瘾后,35.0%性欲减退,58.3%性欲消失;性行为方式:吸毒前96.7%以性交为主,吸毒成瘾后仅15.0%以性交为主(P<0.001),85%以非性交接触为主;海洛因成瘾后性能力明显障碍,性交次数由吸毒前平均4.9±1.6次/周减少至平均0.4±0.2次/周(P<0.01)。结果表明:海洛因对女性生理机能和心理卫生具有明显损害作用。 相似文献