全文获取类型
收费全文 | 160933篇 |
免费 | 14214篇 |
国内免费 | 8990篇 |
专业分类
耳鼻咽喉 | 1594篇 |
儿科学 | 2311篇 |
妇产科学 | 3270篇 |
基础医学 | 17237篇 |
口腔科学 | 3233篇 |
临床医学 | 20420篇 |
内科学 | 24796篇 |
皮肤病学 | 1920篇 |
神经病学 | 8250篇 |
特种医学 | 5388篇 |
外国民族医学 | 63篇 |
外科学 | 16317篇 |
综合类 | 25407篇 |
现状与发展 | 30篇 |
一般理论 | 18篇 |
预防医学 | 11425篇 |
眼科学 | 4464篇 |
药学 | 16697篇 |
140篇 | |
中国医学 | 8317篇 |
肿瘤学 | 12840篇 |
出版年
2024年 | 457篇 |
2023年 | 2329篇 |
2022年 | 5475篇 |
2021年 | 7061篇 |
2020年 | 5352篇 |
2019年 | 4753篇 |
2018年 | 5096篇 |
2017年 | 4790篇 |
2016年 | 4255篇 |
2015年 | 6704篇 |
2014年 | 8524篇 |
2013年 | 8497篇 |
2012年 | 12577篇 |
2011年 | 13417篇 |
2010年 | 8994篇 |
2009年 | 7386篇 |
2008年 | 9261篇 |
2007年 | 9285篇 |
2006年 | 8912篇 |
2005年 | 8304篇 |
2004年 | 5838篇 |
2003年 | 5346篇 |
2002年 | 4470篇 |
2001年 | 3843篇 |
2000年 | 3617篇 |
1999年 | 3544篇 |
1998年 | 1893篇 |
1997年 | 1867篇 |
1996年 | 1454篇 |
1995年 | 1348篇 |
1994年 | 1224篇 |
1993年 | 708篇 |
1992年 | 1153篇 |
1991年 | 1031篇 |
1990年 | 862篇 |
1989年 | 745篇 |
1988年 | 692篇 |
1987年 | 579篇 |
1986年 | 450篇 |
1985年 | 357篇 |
1984年 | 217篇 |
1983年 | 187篇 |
1982年 | 121篇 |
1981年 | 107篇 |
1980年 | 75篇 |
1979年 | 149篇 |
1978年 | 111篇 |
1977年 | 83篇 |
1974年 | 94篇 |
1972年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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
72.
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
73.
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
74.
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
75.
目的 回顾性分析1126例住院心脏病病人的病因,为今后防治工作提供初步依据.方法 收集2000年1月~2004年12月住我科的心脏病病人的病历资料,用回顾性方法进行统计分析.结果 1126例心脏病病人的病因分别是高心病(34.2%)、冠心病(18.0%)、肺心病(13.7%)、联合性心脏病(11.9%)、扩心病(7.8%)、风心病(5.8%)、退行性心脏瓣膜病(3.9%)、急性病毒性心肌炎(2.8%),先心病(1.9%).结论 今后防治工作重点在于实施有效的高血压病和冠心病的防治,还要重视慢性肺心病和风心病的防治. 相似文献
76.
Forty samples of cord blood lymphocytes were isolated from 40 normal healthy full-term newborns. The initial 20 samples were used to determine the dose-response curve of three different thymic extracts (TP-1, bovine thymic extract; TG-15-I and TG-15-II, both porcine thymic extracts) and one of renal origin (KG-1) as a control of non-lymphoid organ extract, by measuring the E-rosette T cells. Results showed that E-rosette T cells increased significantly when the thymic extract concentration was increased to 12.5 micrograms/ml. However, there was no statistical difference between TP-1, TG-15-I and TG-15-II in the increase of E-rosette-forming cells. The remaining 20 samples were preincubated with 0, 12.5, 25 or 50 micrograms/ml of thymic extracts. It was observed that the lymphoproliferation, interleukin-2 (IL-2), gamma-interferon (IFN-gamma) and tumor necrotic factor (TNF) production were all significantly increased after thymic extract treatment. No statistical difference between these three thymic preparations in the stimulation of lymphoproliferative response was found. However, among the three thymic extracts, TP-1 appears to induce the highest amounts of IL-2, IFN-gamma and TNF. Of the TG-15-I and TG-15-II, the former stimulates higher IL-2 production whereas the latter enhances IFN-gamma and TNF production. The different immunostimulating effects and potencies that these three thymic extracts showed may reflect not only the species difference but also the difference in preparation procedures. Different components in these thymic extracts may be responsible for different biological activities. Results from these comparative studies may provide useful information in future clinical trials for the treatment of the primary immunodeficiency diseases according to their pathogenesis and may also indicate a possible beneficial effect of the combination of chemotherapy and thymic extracts. 相似文献
77.
以曼氏血吸虫的虫卵和成虫免疫家兔后所产生的特异性抗体,可用以日本血吸虫虫卵、尾蚴和成虫为抗原分别进行的COP,CHR和ELACIEP测出,表明两种人体血吸虫存有显著的交叉抗原成分。应用此种血清交叉反应性,以检测抗异种人体血吸虫的抗体,似有效而可取的,可用以辅助诊断援外回国人员是否感染国外人体血吸虫病。 相似文献
78.
白术、枳实、玫瑰花挥发油-β-环糊精包合物的制备工艺研究 总被引:3,自引:0,他引:3
目的确定白术、枳实、玫瑰花挥发油-β-环糊精包合物的最佳包合工艺。方法采用正交试验法,对挥发油与β-环糊精的包合进行3因素3水平考察。结果挥发油与β-CD投料比为1:9,β-CD与加水量的比为9:100倍,包合时间为4h,包合率为85.3%。结论用此法得到的挥发油-β-环糊精包合物的包合率较高,包合物性质稳定,而且包合操作简单。 相似文献
79.
资料收集中的护患沟通交流技巧 总被引:1,自引:0,他引:1
蒋银芬 《实用临床医药杂志》2006,2(1):14-15
正确的护理评估依赖于资料收集的充足与准确。因此资料收集是否全面、系统、真实、及时,直接影响着护理诊断和护理措施的正确制订。如何应用护患沟通技巧,准确、及时、全面地收集资料保证护理质量是当今护理工作应关注的重要内容。 相似文献
80.
An unusual, elongated, refractile cell morphology was observed in keratinocytes cultured from three patients with non-lethalis forms of junctional epidermolysis bullosa (JEB). To determine whether these changes might be related to altered cell adhesion, keratinocyte strains established from one patient were examined for adhesive, structural, and functional characteristics. JEB keratinocytes expressed keratin tonofilaments, as determined by staining with AE1 monoclonal antibodies and direct observation of tonofilaments by electron microscopy. JEB keratinocytes showed diminished cell-substratum adhesions, judged by interference reflection microscopy. Areas of diminished cell-substratum adhesion corresponded to F-actin-rich cell adhesions (focal adhesions) and not to cellular areas that abundantly express hemidesmosomal antigens. Analysis of cell-substratum adhesion by electron microscopy revealed extensive areas of cell-substratum separation in JEB keratinocytes that were not present in normal keratinocytes maintained in serum-free medium. Normal keratinocytes displayed numerous regions of focal contact between the ventral plasma membrane and the culture substratum, but these structures were not seen in JEB keratinocytes. Bundled actin filaments (stress fibers) were greatly diminished in expected regions of cell-substratum adhesion in JEB keratinocytes and, instead, displayed disorganized individual filaments. The growth rate of JEB keratinocytes was quite slow in culture, with a population doubling time of 2.7 d versus 1.5 d for normal keratinocytes under identical conditions. JEB keratinocytes also displayed a reduced ability to aggregate into colonies upon exposure to medium with increased extracellular calcium. JEB keratinocytes thus display adhesive, structural, and functional abnormalities that suggest this cell type may be central to the pathogenesis of junctional epidermolysis bullosa. Study of affected keratinocytes could be important to characterize associated molecular pathologies. 相似文献