全文获取类型
收费全文 | 158921篇 |
免费 | 13823篇 |
国内免费 | 7582篇 |
专业分类
耳鼻咽喉 | 1516篇 |
儿科学 | 2517篇 |
妇产科学 | 3416篇 |
基础医学 | 18029篇 |
口腔科学 | 3580篇 |
临床医学 | 18613篇 |
内科学 | 25717篇 |
皮肤病学 | 2167篇 |
神经病学 | 9020篇 |
特种医学 | 5310篇 |
外国民族医学 | 42篇 |
外科学 | 17361篇 |
综合类 | 21589篇 |
现状与发展 | 20篇 |
一般理论 | 26篇 |
预防医学 | 11265篇 |
眼科学 | 4104篇 |
药学 | 16285篇 |
115篇 | |
中国医学 | 6903篇 |
肿瘤学 | 12731篇 |
出版年
2024年 | 351篇 |
2023年 | 1811篇 |
2022年 | 4241篇 |
2021年 | 5845篇 |
2020年 | 4291篇 |
2019年 | 4033篇 |
2018年 | 4559篇 |
2017年 | 4201篇 |
2016年 | 3806篇 |
2015年 | 5820篇 |
2014年 | 7468篇 |
2013年 | 7908篇 |
2012年 | 11432篇 |
2011年 | 12171篇 |
2010年 | 8297篇 |
2009年 | 6851篇 |
2008年 | 8962篇 |
2007年 | 9017篇 |
2006年 | 8497篇 |
2005年 | 7673篇 |
2004年 | 5716篇 |
2003年 | 5215篇 |
2002年 | 4339篇 |
2001年 | 5312篇 |
2000年 | 4993篇 |
1999年 | 4395篇 |
1998年 | 1959篇 |
1997年 | 1663篇 |
1996年 | 1295篇 |
1995年 | 1223篇 |
1994年 | 1120篇 |
1993年 | 727篇 |
1992年 | 1863篇 |
1991年 | 1671篇 |
1990年 | 1441篇 |
1989年 | 1427篇 |
1988年 | 1307篇 |
1987年 | 1166篇 |
1986年 | 1026篇 |
1985年 | 873篇 |
1984年 | 558篇 |
1983年 | 473篇 |
1982年 | 271篇 |
1981年 | 226篇 |
1980年 | 179篇 |
1979年 | 338篇 |
1978年 | 193篇 |
1974年 | 177篇 |
1973年 | 164篇 |
1972年 | 179篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
肥胖类型与脑卒中亚型的相关性研究 总被引:1,自引:0,他引:1
目的探讨肥胖类型与脑卒中亚型的相关性。方法将573例急性脑卒中患者分为脑出血组126例,脑梗死组447例,脑梗死组再分为脑血栓形成组(215例)和腔隙性脑梗死组(232例),另外选择277例无脑卒中者为对照组。测量腰围、臀围和体重,计算体重指数和腰臀比(WHR),分析肥胖参数与脑卒中各亚组的关系。结果脑卒中各亚组与对照组肥胖发生率差异无显著性意义(P>0.05);各组WHR明显大于对照组(P<0.05)。WHR增大明显增加脑卒中各亚组的危险性(P<0.05);女性腹围增大患腔隙性脑梗死危险性升高(P<0.05);男性体重增加患脑出血的危险性升高(P<0.01)。结论腹型肥胖是脑出血、脑血栓形成和腔隙性脑梗死的危险因素之一。 相似文献
42.
43.
G C Lin 《中华口腔医学杂志》1991,26(3):137-9, 190
From 1955 to 1984, radical neck dissection (RND) had been done in 300 salivary carcinoma patients, 114 of which had regional lymph node metastasis, with a 38% metastatic rate. Respective 3, 5, 10, 15, 20 year survival rates were 76, 64, 47, 35, 35% in a 3 to 20 years follow-up study in 283 patients (94.33%). The following four points are concluded: 1. The metastatic rate is determined not only on tumor staging, but more to its typing (pathologic behaviour). 2. Elective RND gave a better prognosis than therapeutic and negative metastasis has a better survival chance than positive where the low level metastasis is the worst. 3. According to pathologic typing, Elective RND is indicated for undifferentiated adenocarcinoma, high malignant mucoepidermoid carcinoma, squamous cell carcinoma, adenocarcinoma and papillary cystic adenocarcinoma, therapeutic RND for malignant pleomorphic adenoma, acinic cell carcinoma and mucoepidermoid carcinoma. 4. Unilateral RND is indicated for all but sublingual and buccal tumors. 相似文献
44.
While balloon valvuloplasty has been widely used for the treatment of congenital valvular pulmonary stenosis (PS) in children and adults, its use in elderly patients is less common. An 80-year-old woman with congenital valvular PS received valvuloplasty with double-balloon technique. Right ventricle systolic pressure and pulmonary valve systolic pressure gradient decreased from 95 to 44 mm Hg and from 75 to 35 mm Hg, respectively. Follow-up Doppler echocardiography 2 months later showed further decrease in the transvalvular systolic pressure gradient to 29 mm Hg. The patient had symptomatic relief, and no major complication was noted. Balloon pulmonary valvuloplasty can be an effective treatment for elderly patients with congenital valvular PS. 相似文献
45.
Sheng-Chieh Lin Shyh-Dar Shyur Yi-Chun Ma Li-Hsin Huang Hung-Chang Lee Wen-I Lee 《台湾医志》2005,104(6):421-426
X-linked hyper-immunoglobulin M (IgM) syndrome (XHIGM) is a rare genetic primary immunodeficiency disease caused by mutations of the CD40 ligand (CD40L) gene with normal or elevated levels of IgM and markedly decreased serum IgG, IgA, and IgE. Liver disease may occur as a clinical manifestation in XHIGM. This complication appears to increase with age. We report an 18-year-old male patient who had recurrent episodes of acalculous cholecystitis (AC) and sclerosing cholangitis (SC). The diagnosis of XHIGM was confirmed by the finding of CD40L expression < 1% of normal and a tyrosine 169 asparaginase (t526a) mutation in exon 5 (the tumor necrosis factor domain) of the CD40L gene. The patient had direct hyperbilirubinemia (direct bilirubin 5.5 mg/dL, total bilirubin 8.7 mg/dL), cholestasis (alkaline phosphatase 1133 U/L, gamma-glutamyl transferase 1019 U/L) and elevated transaminases (aspartate aminotransferase 70 U/L, alanine aminotransferase 101 U/L). Findings on abdominal ultrasound and abdominal computed tomography were compatible with AC. After the fourth episode of cholecystitis, cholecystectomy and liver biopsy were performed. Operative cholangiography revealed poor opacification of the hepatic duct and proximal common bile duct; the upstream intrahepatic bile ducts were not visualized. The biopsy specimen showed marked fibrosis of the portal areas. Enterococcus species was cultured from the bile. Children or adolescents with recurrent AC and SC should be evaluated for an underlying immunodeficiency syndrome such as XHIGM. 相似文献
46.
BACKGROUND AND PURPOSE: This report describes the results of matched-unrelated-donor transplant for leukemia or myelodysplasia in the first 23 recipient children at a single medical center in Taiwan. METHODS: Between August 1994 and February 2003, 23 consecutive children with leukemia or myelodysplasia underwent matched-unrelated-donor bone marrow transplantation (BMT). The preparative regimen consisted of fractionated total body irradiation and cyclophosphamide in 6 patients; busulfan in combination with etoposide and cyclophosphamide in 4 patients who received cranial irradiation before transplantation; and busulfan and cyclophosphamide in 13 patients. RESULTS: Engraftment was achieved in 91.3% of cases. Acute graft-versus-host disease (GVHD) occurred in 18 of 21 patients who engrafted (85.7%). Event-free survival for all patients was 24.46 +/- 9.24%. The 12 children with standard-risk disease had better event-free survival than the 11 children with high-risk disease (46.88 +/- 15.03% vs 0%, p < or = 0.001). CONCLUSIONS: The major obstacles to successful matched-unrelated-donor BMT are acute GVHD, relapse and infection. Early transplantation and patient selection, prophylactic and therapeutic maneuvers for GVHD, as well as appropriate donor selection and virus prophylaxis may improve the results. 相似文献
47.
In primary visual cortex of hooded rats, pyramidal cells in layer V may be classified as long, medium, or short, on the basis of the layer in which the apical dendrite terminates. The present study determines which of these types of pyramidal cells project to the superior colliculus. Two different strategies were used to label corticotectal cells with horseradish peroxidase (HRP). In the first set of experiments, a large number of corticotectal cells were labeled by retrograde transport following injection of HRP into the superior colliculus. In the second set of experiments, single unit recording was used to identify corticotectal cells physiologically by antidromic activation from the superior colliculus. These cells were then impaled and labeled by intracellular iontophoresis of HRP. The results from both techniques suggest that only long pyramidal cells send an axon to the superior colliculus. These cells are distinguished by an apical dendrite that extends into layer I. We conclude that in hooded rats corticotectal cells in primary visual cortex are the long pyramids in layer V. 相似文献
48.
Delta hepatitis virus infection in China 总被引:1,自引:0,他引:1
D Q Wang H H Cheng G Y Minuk L H Liu C M Anand T C Stowe H X Wang D C Ying Y R Tu K A Buchan 《International journal of epidemiology》1987,16(1):79-83
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China. 相似文献
49.
50.
Zhang Gu-sheng章谷生 Hu Fang-yuan胡方远 Ye Qing-zhen叶庆祯 Yan Yong-tang严咏棠Immunology Laboratory Shanghai Institute of Biologicat Products Shanghai 《中华医学杂志(英文版)》1986,99(4):343-346
Neurotropin (NSP) is an extract isolated from
the skin of rabbits inoculated with vaccinia virus.
The present study examines the possible action of
NSP on the number and function of immunocompe
tent cells in mice. The experiment showed that NSP
had no effect on both T and B lymphocytes of nor-
malimmunized mouse spleen. The degree of plaque
forming cell reaction and titre of specific antibody
showed no significant differences when the NSP
treated group and controls were compared. How-
ever, NSP exhibited promotive effect on specific
antigen binding cells in the early stage of immune
responses. It was also noted that the rosette forming
capacity of human T lymphocytes in vitro was restor-
ed markedly by NSP. These results suggest that
NSP possesses certain immunostimulating activity,
particularly on the specific antigen binding cells and
human T lymphocytes. 相似文献