全文获取类型
收费全文 | 13102篇 |
免费 | 1338篇 |
国内免费 | 84篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 381篇 |
妇产科学 | 261篇 |
基础医学 | 1758篇 |
口腔科学 | 243篇 |
临床医学 | 1665篇 |
内科学 | 2782篇 |
皮肤病学 | 164篇 |
神经病学 | 1297篇 |
特种医学 | 626篇 |
外国民族医学 | 1篇 |
外科学 | 1476篇 |
综合类 | 382篇 |
一般理论 | 9篇 |
预防医学 | 1341篇 |
眼科学 | 221篇 |
药学 | 1074篇 |
中国医学 | 10篇 |
肿瘤学 | 723篇 |
出版年
2021年 | 184篇 |
2020年 | 110篇 |
2019年 | 192篇 |
2018年 | 180篇 |
2017年 | 155篇 |
2016年 | 159篇 |
2015年 | 202篇 |
2014年 | 265篇 |
2013年 | 409篇 |
2012年 | 501篇 |
2011年 | 511篇 |
2010年 | 313篇 |
2009年 | 317篇 |
2008年 | 445篇 |
2007年 | 575篇 |
2006年 | 535篇 |
2005年 | 539篇 |
2004年 | 460篇 |
2003年 | 481篇 |
2002年 | 461篇 |
2001年 | 457篇 |
2000年 | 469篇 |
1999年 | 438篇 |
1998年 | 207篇 |
1997年 | 198篇 |
1996年 | 191篇 |
1995年 | 187篇 |
1994年 | 181篇 |
1993年 | 171篇 |
1992年 | 339篇 |
1991年 | 341篇 |
1990年 | 273篇 |
1989年 | 302篇 |
1988年 | 291篇 |
1987年 | 287篇 |
1986年 | 252篇 |
1985年 | 232篇 |
1984年 | 203篇 |
1983年 | 181篇 |
1982年 | 142篇 |
1981年 | 126篇 |
1980年 | 118篇 |
1979年 | 174篇 |
1978年 | 156篇 |
1977年 | 118篇 |
1976年 | 139篇 |
1975年 | 108篇 |
1974年 | 130篇 |
1973年 | 169篇 |
1972年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Summary: Linear unsaturated nylons 6 u18 and 18 u18 have been made containing a double bond in the center of the diacid segment with potential for additional functionalization. Solution state NMR showed the presence of a small portion of cis amide units. Solid state NMR verified the presence of the double bond in the bulk, and that the polyamides were present in the α‐crystalline form. Thermal stability was comparable to linear saturated nylons, and the melting and crystallization temperatures of the unsaturated nylons were lower compared to the saturated analogs.
82.
83.
Genome-wide linkage analysis of families with obsessive-compulsive disorder ascertained through pediatric probands 总被引:3,自引:0,他引:3
Hanna GL Veenstra-VanderWeele J Cox NJ Boehnke M Himle JA Curtis GC Leventhal BL Cook EH 《American journal of medical genetics》2002,114(5):541-552
The goal of this study was to identify chromosomal regions likely to contain susceptibility alleles for early-onset obsessive-compulsive disorder (OCD). A genome scan was done in 56 individuals from seven families ascertained through pediatric OCD probands; 27 of the 56 subjects had a lifetime diagnosis of definite OCD. Denser mapping of regions on chromosomes 2, 9, and 16 was subsequently done with those subjects and ten additional subjects from the largest family in the study. Direct interviews were completed with 65 of the 66 genotyped individuals. Relatives were interviewed blind to proband status. Of the 65 interviewed individuals, 32 had a lifetime diagnosis of definite OCD. Three of the seven probands had a history of Tourette disorder. Two of the 25 relatives with OCD had a tic history, whereas none of the 33 relatives without OCD had tics. The genome scan consisted of 349 microsatellite markers with an average between-marker distance of 11.3 centiMorgan (cM). Fine mapping was done with 24 additional markers at an average spacing of 1.6 cM. Parametric and nonparametric linkage analyses were conducted using GENEHUNTER(+). The maximum multipoint LOD score with a dominant model was 2.25 on 9p. However, with fine mapping and additional subjects, that LOD score decreased to 1.97. The maximum multipoint nonparametric LOD* score was 1.73 on 19q. The maximum multipoint LOD score with a recessive model was 1.40 on 6p. The results provide suggestive evidence for linkage on 9p and identify regions requiring further study with much larger samples. 相似文献
84.
85.
86.
The extent to which protein synthesis is involved in working memory was investigated with the protein synthesis inhibitor anisomycin (ANI). Rats were trained to perform accurately on a 12-arm radial maze when delays of 240 min were interposed between choice 6 and choice 7. Bilateral hippocampal cannulas were then implanted. Accuracy on choices 7-12 was studied when ANI or saline was injected either 30 min before choice 1 or 5-10 min after choice 6 (Experiment 1). Pretrial injection of ANI significantly impaired performance following the 240-min delay, whereas ANI injected during the delay had no such effect. In Experiments 2 and 3, the ANI-induced amnesia was replicated, and the temporal course of development of the amnesia was determined. Pretrial administration of ANI did not significantly affect retention after a 2-min delay but did produce amnesia after delays of 15 min or longer. These data suggest that protein synthesis is important for the formation of temporary memories, provided the retention interval is long enough. It is suggested that working memory includes both short-term and long-term components. Protein synthesis appears to be important for formation of the long-term component, but not the short-term component, of working memory. 相似文献
87.
S R Bennett J P Greer R S Stein A D Glick J B Cousar R D Collins 《American journal of clinical pathology》1984,82(1):104-109
A case of mycosis fungoides in which pathologic rupture of the spleen led to intraperitoneal hemorrhage and death is described. To our knowledge, splenic rupture has not been reported previously as a cause of death in mycosis fungoides. Immunologic studies demonstrated that the neoplastic cell was a suppressor/cytotoxic T-cell. In most cases of mycosis fungoides or the Sézary syndrome, the neoplastic cell has been a helper/inducer T-cell. This case was very aggressive clinically with prominent visceral involvement and suggests that mycosis fungoides may be clinically diverse as well as immunologically heterogeneous. 相似文献
88.
89.
Radcliffe Jerilynn; Bennett David; Kazak Anne E.; Foley Bernadette; Phillips Peter C. 《Journal of pediatric psychology》1996,21(4):529-539
Examined the adjustment of 6- to 18-year-old children and adolescents(n = 38) 2 to 5 years postdiagnosis of brain tumor with respectto standardized measures of anxiety and depression; self-perceptions;and adaptive living skills. Child, mother, and teacher reportdata were used. Maternal adjustment (anxiety and depression,parenting stress) was also assessed. Children and adolescentssurviving brain tumors reported themselves to be generally withinthe normal range. However, maternal ratings of social problemswere higher than normative scores and significantly lower thannorms on social problems, scholastic competence, and communicationskills. Teacher ratings on the Teacher Rating Form were allwithin normal limits. Maternal adjustment measures were withinthe normal range, although the Parent-Child Dysfunctional Interactionsubscale of the Parenting Stress Index was elevated. No differencesin scores were found between children in regular and specialeducation, or between children who had received radiation andthose who did not. This sample of survivors of pediatric braintumors and their mothers had relatively mild problems in adjustment,supporting a competency-based view of the adaptation of pediatricpatients and their families. 相似文献
90.