全文获取类型
收费全文 | 6618篇 |
免费 | 480篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 199篇 |
妇产科学 | 73篇 |
基础医学 | 921篇 |
口腔科学 | 229篇 |
临床医学 | 648篇 |
内科学 | 1681篇 |
皮肤病学 | 140篇 |
神经病学 | 484篇 |
特种医学 | 454篇 |
外科学 | 899篇 |
综合类 | 117篇 |
一般理论 | 1篇 |
预防医学 | 324篇 |
眼科学 | 127篇 |
药学 | 405篇 |
中国医学 | 5篇 |
肿瘤学 | 387篇 |
出版年
2021年 | 60篇 |
2018年 | 81篇 |
2017年 | 78篇 |
2016年 | 78篇 |
2015年 | 79篇 |
2014年 | 121篇 |
2013年 | 204篇 |
2012年 | 190篇 |
2011年 | 204篇 |
2010年 | 131篇 |
2009年 | 136篇 |
2008年 | 226篇 |
2007年 | 217篇 |
2006年 | 209篇 |
2005年 | 189篇 |
2004年 | 159篇 |
2003年 | 169篇 |
2002年 | 155篇 |
2001年 | 207篇 |
2000年 | 193篇 |
1999年 | 182篇 |
1998年 | 141篇 |
1997年 | 141篇 |
1996年 | 143篇 |
1995年 | 106篇 |
1994年 | 104篇 |
1993年 | 108篇 |
1992年 | 175篇 |
1991年 | 169篇 |
1990年 | 171篇 |
1989年 | 202篇 |
1988年 | 178篇 |
1987年 | 155篇 |
1986年 | 154篇 |
1985年 | 126篇 |
1984年 | 108篇 |
1983年 | 72篇 |
1982年 | 71篇 |
1981年 | 82篇 |
1980年 | 85篇 |
1979年 | 85篇 |
1978年 | 83篇 |
1977年 | 71篇 |
1976年 | 78篇 |
1975年 | 69篇 |
1972年 | 67篇 |
1970年 | 65篇 |
1965年 | 67篇 |
1964年 | 56篇 |
1960年 | 70篇 |
排序方式: 共有7138条查询结果,搜索用时 15 毫秒
11.
Ophira Salomon Joseph Moisseiev Tamara Vilganski Rima Dardik Shimon Kurtz Eva Shpringer David M Steinberg Nurit Rosenberg 《Blood coagulation & fibrinolysis》2006,17(6):485-488
To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion. 相似文献
12.
14.
SOLOMON HOWARD M.; FERENZ RAYANNE L.; KENNEDY GERALD L. JR.; STAPLES ROBERT E. 《Toxicological sciences》1991,16(3):414-422
Developmental Toxicity of Dimethylacetamide by Inhalation inthe Rat. SOLOMON, H. M., FERENZ, R. L., KENNEDY, G. L., ANDSTAPLES, R. E. (1991). Fundam. Appl. Toxicol. 16, 414422.Dimethylacetamide (DMAC) is a widely used industrial solvent.It has been reported to be teratogenic when given to rats byinjection or following dermal application. Most of these studiesemployed large single doses and did not examine both the fetaland the maternal response. In this study, groups of pregnantCrl:CD rats were exposed to 32, 100, or 282 ppm DMAC by inhalationfor 6 hr/day from Days 6 through 15 of gestation (day on whichcopulation plug was detected was termed Day 1G). A control groupof chambered pregnant rats was exposed simultaneously to aironly. All female rats were euthanized on Day 21G. At 282 ppm,both maternal weight gain during the exposure period and fetalweight were significantly decreased and accompanied by a significantdose-response trend. These effects were not seen in rats inhalingeither 32 or 100 ppm. Fetal resorptions were not increased inany of the groups exposed to DMAC. Fetal incidences of external,visceral, or skeletal variations and malformations were similarbetween the test and control groups. Therefore, both fetal andmaternal toxicity were noted at 282 ppm and the no-observedadverse-effect level under these experimental conditions was100 ppm for both the dam and the conceptus. DMAC was not demonstratedto produce malformations in the rat fetus even at a level thatwas toxic to the dam. 相似文献
15.
16.
E L Steinberg I Reider S Barak O Khermosh S Wientroub 《Journal of pediatric orthopedics》1990,10(4):540-541
A child with unilateral dysplasia of the superior articular facet of the axis is described. This congenital anomaly, due to incomplete ossification, may be a cause of torticollis, although no signs of instability were noted. 相似文献
17.
Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma 总被引:9,自引:3,他引:6
Weisenburger DD; Gordon BG; Vose JM; Bast MA; Chan WC; Greiner TC; Anderson JR; Sanger WG 《Blood》1996,87(9):3860-3868
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study. 相似文献
18.
Thomas McLaughlin Bruce Steinberg Thomas Mulholland Lars Friberg 《International journal of psychophysiology》2005,56(2):143-155
EEG feedback methods, which link the occurrence of alpha to the presentation of repeated visual stimuli, reduce the relative variability of subsequent, alpha-blocking event durations. The temporal association between electro-cortical field activation and regional cerebral blood flow (rCBF) led us to investigate whether the reduced variability of alpha-blocking durations with feedback is associated with a reduction in rCBF variability. Reduced variability in the rCBF response domain under EEG feedback control might have methodological implications for future brain-imaging studies. Visual stimuli were randomly presented to seven subjects, contingent upon the occurrence of alpha (alpha-contingent stimulation (ACS)) or alpha-blocking (not-alpha-blocking-contingent stimulation (NACS)) events. We employed a within-subjects design. rCBF was measured from multiple, cortical and sub-cortical regions. The primary dependent variables were the Mean, Standard Deviation and the ratio of Mean/Standard Deviation of: 1) the alpha-blocking response durations and 2) the temporally summated rCBF responses within the Visual Associative regions of interest (ROIs). Additional within-subjects rCBF measures were derived to quantify the variance-reducing effects of ACS across multiple, distributed areas of the brain. Both EEG and rCBF measures demonstrated decreased variability under ACS. This improved control was seen for localized as well as anatomically distributed rCBF measures. 相似文献
19.
JR Turnbull Ch Assaf ChC Zouboulis B Tebbe 《Journal of the European Academy of Dermatology and Venereology》2004,18(3):353-355
The naevus of Ota (naevus fusculocoeruleus ophthalmomaxillaris) was first described by the Japanese dermatologist M. T. Ota in 1939. It has a reported incidence of 0.2% to 1% in the Japanese population. It usually occurs in the skin innervated by the first or second branch of the trigeminal nerve. The naevus comprises dermal melanocytes and is congenital or acquired during adolescence. Commonly associated lesions include scleral melanocytosis and other ocular manifestations as well as lesions of the tympanic membrane, oral and intranasal mucosa and leptomeninges. Diseases associated with Ota's naevus in rare cases are open-angle glaucomas and melanoma. The naevus of Ota in Europeans is a rare manifestation. We report the very rare case of a bilateral naevus of Ota associated with enoral melanocytosis in a white European person. 相似文献
20.
This study retrospectively evaluated the outcome for patients undergoing herniorraphy for chronic groin pain due to posterior inguinal wall deficiency, and correlated the outcome with preoperative investigation findings. There were 47 patients (with a total of 52 herniorraphies) who were contacted by phone between six and 50 months post surgery. Subjects had a diagnosis of posterior inguinal wall deficiency made on history and clinical examination. Thirty seven patients had an ultrasound scan prior to the surgery (three bilateral) with a total of 40 symptomatic groins scanned. There were 26 abnormal scans (22 posterior inguinal wall deficiency and four hernias) and 14 normal scans. Twenty nine patients had a technetium-99m bone scan with 22 having increased uptake at the symptomatic pubic tubercle, while 13 had increased uptake at other sites in the groin. Seventy seven percent of patients had a full return to sport after surgery and the average time to return to sport was four months. There was no significant difference in outcome between subjects who had an abnormal ultrasound scan on the symptomatic side and those who had a normal scan. There was a significant difference in outcome between patients who had a bone scan with increased uptake at the symptomatic pubic tubercle and those who did not (p < 0.04). Our study supports previous research that good results can be obtained with surgery when posterior inguinal wall deficiency is the sole diagnosis. Ultrasound scan does not appear to aid in predicting surgical outcome, while the role of isotope bone scanning requires further study. 相似文献