全文获取类型
收费全文 | 22038篇 |
免费 | 1441篇 |
国内免费 | 176篇 |
专业分类
耳鼻咽喉 | 396篇 |
儿科学 | 416篇 |
妇产科学 | 388篇 |
基础医学 | 3183篇 |
口腔科学 | 314篇 |
临床医学 | 1972篇 |
内科学 | 4346篇 |
皮肤病学 | 626篇 |
神经病学 | 1738篇 |
特种医学 | 1096篇 |
外科学 | 3194篇 |
综合类 | 173篇 |
现状与发展 | 1篇 |
一般理论 | 24篇 |
预防医学 | 1426篇 |
眼科学 | 590篇 |
药学 | 1862篇 |
中国医学 | 187篇 |
肿瘤学 | 1723篇 |
出版年
2023年 | 149篇 |
2022年 | 340篇 |
2021年 | 628篇 |
2020年 | 345篇 |
2019年 | 574篇 |
2018年 | 634篇 |
2017年 | 503篇 |
2016年 | 638篇 |
2015年 | 824篇 |
2014年 | 1068篇 |
2013年 | 1189篇 |
2012年 | 1797篇 |
2011年 | 1780篇 |
2010年 | 1123篇 |
2009年 | 934篇 |
2008年 | 1312篇 |
2007年 | 1297篇 |
2006年 | 1227篇 |
2005年 | 1133篇 |
2004年 | 981篇 |
2003年 | 828篇 |
2002年 | 806篇 |
2001年 | 308篇 |
2000年 | 312篇 |
1999年 | 267篇 |
1998年 | 155篇 |
1997年 | 134篇 |
1996年 | 132篇 |
1995年 | 111篇 |
1994年 | 82篇 |
1993年 | 88篇 |
1992年 | 170篇 |
1991年 | 157篇 |
1990年 | 140篇 |
1989年 | 177篇 |
1988年 | 133篇 |
1987年 | 120篇 |
1986年 | 104篇 |
1985年 | 101篇 |
1984年 | 88篇 |
1983年 | 64篇 |
1982年 | 63篇 |
1981年 | 52篇 |
1980年 | 45篇 |
1979年 | 47篇 |
1978年 | 39篇 |
1975年 | 34篇 |
1974年 | 40篇 |
1973年 | 42篇 |
1972年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
3-Monochloro-1,2-propanediol (MCPD) is a well-known by-product of acid-hydrolyzed soy sauce during its manufacturing process. MCPD has been reported genotoxic in vitro, and reproductive toxicity and carcinogenicity in rats. To evaluate the immunomodulatory effect of MCPD on murine splenocyte and macrophage in vitro, we investigated splenocyte blastogenesis by concanavalin A (Con A), anti-CD3, and lipopolyssacharide (LPS), the production of cytokines from splenocyte, and the activity of mouse peritoneal macrophages. There was a significant decrease in lymphocyte blastogenesis to Con A or anti-CD3 at subtoxic dose of MCPD. A significant decrease in splenocyte blastogenesis to LPS was also observed. The production level of interferon (IFN)-gamma on splenocyte culture with Con A was significantly reduced at the higher concentration than 1.0mM of MCPD. The levels of interleukin (IL)-4 and IL-10 were also decreased at high concentrations of MCPD. There was a significant decrease in production of nitric oxide (NO) by peritoneal macrophages treated with MCPD. MCPD also inhibits tumor necrosis factor (TNF)-alpha production of stimulated macrophages. These results indicate that MCPD might be able to reduce the functionality of lymphocytes and peritoneal macrophages in vitro. 相似文献
42.
Lung function in atrial septal defect after heart surgery. 总被引:3,自引:0,他引:3
Lung volume, indices of lung elasticity and airway patency were measured in 74 patients, 9-21 yr old (15.0 +/- 2.5 yr) with atrial septal defect (secundum type) from 2-11 (5.1 +/- 2.5) yr after successful surgical correction. Clinical condition in all patients was classified as excellent. Heart surgery was performed at the age of 4-14.8 (9.9 +/- 3.0) yr. Lung function abnormalities were found in 35 (47.3%) patients. Lung recoil pressure was significantly increased in 24 (32.4%) patients. The mean value of lung recoil pressure at 100% of total lung capacity reached 123 +/- 31% of the predicted value (P < 0.0001). Specific static compliance was within normal limits. Specific airway conductance was significantly reduced in 13 (17.6%) patients. Maximum expiratory flow at 25% of vital capacity was significantly reduced in 4 (5.4%) patients. Static lung volumes did not differ from reference values. Since various abnormalities of lung function tests (most frequently the tests suggested increased lung stiffness and obstruction of larger airways) were revealed in almost half of the studied children and adolescents after successful surgery for atrial septal defect, we propose to carry out lung function tests routinely as another criterion of health conditions in these patients. 相似文献
43.
Si Chan Sung Yun Hee Chang Jong Soo Woo 《European journal of cardio-thoracic surgery》2007,31(4):742-743
We developed a technique of translocation of the pulmonary artery anterior to the ascending aorta without transection of the aorta in the repair of tetralogy of Fallot with absent pulmonary valve. Our technique includes detachment of the main pulmonary artery (MPA) from the pulmonary annulus, vertical division of the MPA, anterior translocation of the pulmonary artery with patch augmentation between the vertically divided MPA. 相似文献
44.
45.
Sarah M Cowgill Desiree V Villadolid Sam Al-Saadi Alexander S Rosemurgy 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(3):336-343
OBJECTIVES: The impact of preoperative endoscopic therapy on the difficulty of laparoscopic Heller myotomy and the impact of the difficulty of the myotomy on long-term outcome has not been determined. This study was undertaken to determine whether preoperative therapy impacts the difficulty of laparoscopic Heller myotomy and whether preoperative therapy or difficulty of myotomy impacts long-term outcomes. METHODS: Since 1992, 305 patients, 56% male, median age 49 years, underwent laparoscopic Heller myotomy and were prospectively followed. The difficulty of the laparoscopic Heller myotomy was scored by the operating surgeon for the most recent 170 consecutive patients on a scale of 1 (easiest) to 5 (most difficult). Patients scored their symptoms before and after myotomy using a Likert scale from 0 (never/not bothersome) to 10 (always/very bothersome). RESULTS: Before myotomy, 66% of patients underwent endoscopic therapy: 33% dilation, 11% Botox, and 22% both. Preoperative endoscopic therapy did not correlate with the difficulty of the myotomy (P=NS). Median follow-up was 25 months. Regardless of the difficulty of the myotomy, dysphagia improved with myotomy (P<0.0001). By regression analysis, the frequency and severity of post-myotomy dysphagia correlated with neither preoperative endoscopic therapy nor the difficulty of the myotomy. CONCLUSIONS: Laparoscopic Heller myotomy improves the frequency and severity of dysphagia. The difficulty of laparoscopic Heller myotomy is not impacted by preoperative therapy, and neither preoperative therapy nor difficulty of the myotomy impact long-term outcome. 相似文献
46.
Jong Hun Kim Kwang-Yeol Park Sang Won Seo Duk L. Na Chin-Sang Chung Kwang Ho Lee Gyeong-Moon Kim 《JOURNAL OF CLINICAL NEUROLOGY》2007,3(1):62-66
The retrosplenial cortex is a cytoarchitecturally distinct brain structure located in the posterior cingulate gyrus and bordering the splenium, precuneus, and calcarine fissure. Functional imaging suggests that the retrosplenium is involved in memory, visuospatial processing, proprioception, and emotion.We report on a patient who developed reversible verbal and visual memory deficits following a stroke. Neuropsychological testing revealed both anterograde and retrograde memory deficits in verbal and visual modalities. Brain diffusion-weighted and T2-weighted magnetic resonance imaging (MRI) demonstrated an acute infarction of the left retrosplenium. 相似文献
47.
Edward L. Morgan Brandon N. Morgan Elisabeth A. Stein Elizabeth L. Vitrs Marilyn L. Thoman Sam D. Sanderson Joy A. Phillips 《Vaccine》2009
A conformationally biased, agonist of human C5a65–74 (EP67) was assessed for its adjuvant activities in vitro and in vivo. EP67 induced the release of the inflammatory (Th1) type cytokines from C5a receptor (CD88)-bearing antigen presenting cells (APC). EP67 did not induce the release of these cytokines from splenic APCs obtained from C5a receptor knockouts (CD88−/−). Serum from mice immunized with EP67–ovalbumin (OVA) contained high OVA-specific antibody (Ab) titers [IgG1, IgG2a (IGg2c), IgG2b]. Mice receiving OVA alone produced only IgG1 Abs, indicating the ability of EP67 to induce a Th1-like Ab class switch. Spleen cell cultures from wild type mice but not CD88−/− mice showed an enhanced OVA-specific proliferative response in vitro. These results indicate the ability of EP67 to drive a Th1-mediated immune response and its potential use as a unique adjuvant. 相似文献
48.
Jong S. Kim 《Journal of the neurological sciences》1996,140(1-2):123-128
Bilateral perioral sensory dysfunction due to unilateral cerebral lesion is rare, and has been thought to be caused by midline brainstem lesions. Six patients are described herewith, with bilateral perioral sensory symptoms due to unilateral strokes that do not involve the mid-brainstem region. Brain-computed tomographic scan and magnetic resonance imaging demonstrated unilateral cerebral strokes in the thalamus, posterior limb of the internal capsule, basal ganglia, fronto-parietal cortex and the insular-frontal subcortical area. This observation suggests that bilateral perioral sensory symptoms do not have a localizing value. Possible pathogenetic mechanisms for this sign are discussed. 相似文献
49.
Variation of prostate-specific antigen expression in different tumour growth patterns present in prostatectomy specimens 总被引:3,自引:0,他引:3
M. P. W. Gallee E. Visser-de Jong J. A. G. M. van der Korput Th. H. van der Kwast F. J. W. ten Kate F. H. Schroeder J. Trapman 《Urological research》1990,18(3):181-187
Summary A series of 55 randomly chosen radical prostatectomy specimens was analyzed for expression of prostate-specific antigen (PSA) by immunohistochemical techniques. Tissue sections were selected in such a manner that in addition to glandular benign prostatic hyperplasia (BPH), one or more different prostatic tumour growth patterns were present. Four monoclonal antibodies, directed against three different PSA epitopes, and one polyclonal anti-PSA antiserum were used. Expression of PSA was compared with that of prostate-specific acid phosphatase (PAP), recognized by two different polyclonal antisera. A critical dilution aimed at a maximum of staining intensity on BPH tissue sections was chosen for all antibodies. Anti-PSA and anti-PAP antisera stained essentially all BPH samples (over 90%). Irrespective of the nature of the antibodies used, PSA expression was found to be decreased in prostatic carcinoma. A clear cut relationship was found between immunoreactivity for PSA and the degree of differentiation of the tumour area. Under the experimental conditions used the PSA monoclonal antibodies stained only 1 out of 10 undifferentiated carcinomas, whereas 50% to 70% of the well- and moderately-differentiated carcinomas showed immunoreactivity. This correlation was less pronounced with the PAP staining pattern. If the PSA antibody titer was raised the percentage of clearly staining undifferentiated carcinomas could be considerably increased (up to 60%–100%), indicating that PSA expression is not absent, but lowered in most (if not all) undifferentiated carcinomas. 相似文献
50.