全文获取类型
收费全文 | 20909篇 |
免费 | 2097篇 |
国内免费 | 1395篇 |
专业分类
耳鼻咽喉 | 172篇 |
儿科学 | 324篇 |
妇产科学 | 267篇 |
基础医学 | 2097篇 |
口腔科学 | 496篇 |
临床医学 | 2563篇 |
内科学 | 2713篇 |
皮肤病学 | 215篇 |
神经病学 | 962篇 |
特种医学 | 961篇 |
外国民族医学 | 5篇 |
外科学 | 2274篇 |
综合类 | 4024篇 |
现状与发展 | 5篇 |
一般理论 | 1篇 |
预防医学 | 1590篇 |
眼科学 | 684篇 |
药学 | 2030篇 |
23篇 | |
中国医学 | 1323篇 |
肿瘤学 | 1672篇 |
出版年
2024年 | 98篇 |
2023年 | 336篇 |
2022年 | 845篇 |
2021年 | 1156篇 |
2020年 | 851篇 |
2019年 | 661篇 |
2018年 | 634篇 |
2017年 | 681篇 |
2016年 | 576篇 |
2015年 | 885篇 |
2014年 | 1125篇 |
2013年 | 1187篇 |
2012年 | 1837篇 |
2011年 | 1836篇 |
2010年 | 1263篇 |
2009年 | 1105篇 |
2008年 | 1269篇 |
2007年 | 1109篇 |
2006年 | 1046篇 |
2005年 | 1001篇 |
2004年 | 767篇 |
2003年 | 778篇 |
2002年 | 672篇 |
2001年 | 523篇 |
2000年 | 420篇 |
1999年 | 257篇 |
1998年 | 187篇 |
1997年 | 146篇 |
1996年 | 93篇 |
1995年 | 106篇 |
1994年 | 89篇 |
1993年 | 66篇 |
1992年 | 89篇 |
1991年 | 83篇 |
1990年 | 60篇 |
1989年 | 55篇 |
1988年 | 37篇 |
1987年 | 34篇 |
1986年 | 40篇 |
1985年 | 28篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1982年 | 15篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 18篇 |
1976年 | 16篇 |
1975年 | 16篇 |
1971年 | 18篇 |
1967年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
PCR-SSCP法检测结核分枝杆菌耐药性 总被引:10,自引:0,他引:10
目的:探讨耐多药结核分枝杆菌耐药基因突变与耐药性的关系以及聚合酶链反应-单链构象多态性分析(poly merase chain reaction-single strand cinfomlation polymorphism,PCR-SSCP)方法的临床应用价值。方法:用PCR-SSCP方法检测58株结核分枝杆菌临床分离株katG,rpoB,rpsL基因突变并与常规药敏试验检测结果进行对比。结果:经常规药敏试验检测,58株结核分枝杆菌临床分离株中共有41株耐药,其中,耐异烟肼(INH)为35株,高耐药株27株;耐利福平(RFP)为31株,高耐药株24株;耐链霉素(SM)有31株,高耐药株26株。同时耐3种药物的有21株(51.2%),耐2种药物的14株(34.1%),单耐药株6株(14.6%).PCR-SSCP方法对58株临床分离株katG,rpoB,rpsL基因突变的检测率为40%(23/58),45%(26/58),38%(22/58),其中检出3个基因同时突变的有13株(32%),2种基因突变的12株(29%),1种基因突变的有10株(23.8%).常规药敏试验与PCR-SSCP法检出结核分枝杆菌同时耐3种药物的符合率为61.9%(13/21),检出耐2种药物的符合率为85.70k,(12/14),检出耐1种药物的符合率为50%(3/6).高耐药株中突变率为80.5%(62/77),低耐药株中突变率为60%(12/20).结论:PCR-SS-CP方法对耐2种以上药物的结核杆菌检出率较高,且耐药基因突变率随着耐药浓度增高而增高。将PCR-SSCP法与药敏试验联合应用可互相弥补,已成为临床指导用药的好方法。 相似文献
32.
Objective:To evaluate the feasibility and safety of prenatal diagnosis by traneabdominal chorionic villus sam-pling(TA-CVS)via the guidance of B-mode ultrasound in the first trimester of gestation.To explore the technique of long time culture and chromosome preparation of villi in early pregnancy.To evaluate the feasibility of the above techniques in the application of the prenatal cytogenetic diagnosis.Methods:One hundred and thirty-five singleton pregnancies at risk were referred from January 2001 to Decem-ber 2007.Results:The average maternal age was 35.2 years.TA-CVS was performed in the 10~13th weeks of gestation and the average gestational age was 10.89 weeks.All attempts at sampling were successful.The rate of operation-associated fetal loss was 0.74%.The failure rate of prenatal diagnosis because of inadequate amount of specimen was 0.The average culture time was 5-7 days.The success rate of the cell culture was 98.5%.No maternal con-temination and bacterial contamination happened.Fifteen cases of abnormal karyotype and one case of confined pla-cantel mosaiciem were diagnosed.Conclusion:TA-CVS appears to be safe and feasible and might to be offered in the prenatal diagnosis in the first trimester of gestation.The technique of long time culture and chromosome preparation of villi is stable and reliable.It is feasible to apply these techniques in the clinical practice of prenatal cytogenetic diagnose in the early pregnancy. 相似文献
33.
大肠海绵状血管瘤的诊治(附8例报告) 总被引:2,自引:0,他引:2
目的 探讨大肠海绵状血管瘤的临床特点、诊治原则和疗效。方法回顾1997年至2004年收治的8例大肠海绵状血管瘤患者的临床资料。结果8例患者平均年龄18岁.其中直肠海绵状血管瘤4例.直肠和乙状结肠海绵状血管瘤3例.金大肠海绵状血管瘤1例。临床表现为反复发作的无痛性便血和贫血。术前行电子结肠镜、腹部X线平片、气钡双重对比造影、CT和MRI等检查明确诊断。昕有患者均行于术治疗.平均随访36月(10~96月).全部治愈。结论增强对本病的认识.重视电亍二结肠镜仵大肠海绵状血管瘤的首诊作用.影像学检杏进一步确定病变部位和血管瘤的范围,手术治疗是有效的治疗手段。 相似文献
34.
35.
Howard B Moss Thomas L Hardie John P Dahl Wade Berrettini Ke Xu 《Neuropsychopharmacology》2007,61(8):974-978
BACKGROUND: Some studies have associated alcohol dependence (AD) with the human serotonin (5-HT)(1B) receptor (HTR1B). This investigation explored the functional responsivity of HTR1B in abstinent AD men using a sumatriptan challenge, while measuring genetic heterogeneity in the HTR1B promoter. METHODS: Abstinent AD men (n = 27) and abstinent men without any alcohol use disorder (n = 19) were administered 6 mg of sumatriptan succinate, subcutaneously. Plasma samples collected over the following 2 hours were assayed for growth hormone (GH) concentrations. His DNA was genotyped for the A-161T and T-261G polymorphisms of the HTR1B promoter and diplotypes determined. RESULTS: Integrated GH responses were predicted by interactions of AD and promoter diplotypes, as well as subject ethnicity. The final model accounted for nearly 35% of the variance in GH responses. Post hoc evaluation revealed that AD was associated with a blunting of GH secretion only among individuals with the most common HTR1B diplotype (TT/TT). CONCLUSIONS: A blunting of GH responses in abstinent AD men was observed only among those with the most common HTR1B promoter diplotype. Less common promoter diplotypes appeared protective. Controlling for genetic background is a useful augmentation of case-control pharmacological challenge strategies designed to elucidate the psychobiology of AD and other complex disorders. 相似文献
36.
I liac artery rupture is a rare complication of post-stenting angioplasty and can lead to massive life-threatening haemorrhage. Conventional surgery can not repair the damaged vessel easily and may cause substantial blood loss and high operative morbidity and mortality. We report our experience with a self-expanding covered endoprosthesis for endovascular repair of the rupture of an iliac artery caused by stenting angioplasty. 相似文献
37.
The article analyses the experience in 11 reconstructions of the pharynx and cervical esophagus with a free vascularized jejunal segment employing microsurgical technique for squamous cell carcinoma of the upper digestive tract. The operative technique is described. It is noted that this operative procedure is a difficult method of surgical management of defects in the pharynx and cervical esophagus and is attended in some cases with complications. From personal experience and review of the literature, the authors conclude that autotransplantation of a free vascularized jejunal segment with the use of microsurgical technique is the best method for reconstruction of defects in the pharynx and cervical esophagus. 相似文献
38.
Partial splenic embolization for hypersplenism concomitant with or after arterial embolization of hepatocellular carcinoma in 30 patients 总被引:15,自引:0,他引:15
Ming-Jun Han Han-Guo Zhao Ke Ren Dong-Chun Zhao Ke Xu Xi-Tong Zhang 《Cardiovascular and interventional radiology》1997,20(2):125-127
Purpose To study the value of partial splenic embolization (PSE) for the treatment of hypersplenism in patients undergoing embolization
of hepatocellular carcinoma (HCC).
Methods Transcatheter hepatic arterial embolization (THAE) combined with PSE was performed in 30 patients with HCC complicating liver
cirrhosis, portal hypertension, and hypersplenism. Gelfoam sponge was used as the embolic material for PSE and limited to
100–150 pieces.
Results More than 50% of splenic parenchyma was infarcted in 27 patients. Leukopenia and thrombocytopenia were corrected by PSE in
25 of 27 patients with hypersplenism. In 26 patients with esophageal varices, including 5 patients with bleeding, no rebleeding
occurred during a 6–17 month follow-up. Hypersplenism was not corrected in 2 of 3 patients whose infarcted splenic parenchyma
was less than 50%. No splenic abscesses or other severe complications were observed. Of the 30 patients treated, 19 are still
alive after 1 year.
Conclusions THAE combined with PSE is a safe and effective measure for patients with HCC. 相似文献
39.
ATP片剂的UV—HPLC测定 总被引:2,自引:0,他引:2
采用UV-HPLC法测定ATP片剂的含量,较地方标准收载的方法方便易行,重现性好。测定的回收率为100.8±1.5%。 相似文献
40.
血管内皮生长因子受体启动子驱动重组腺病毒双自杀基因系统选择性杀伤大肠癌细胞 总被引:4,自引:0,他引:4
Rong-kai Lin Zong-hai Huang Guo-qiang Su Zhi-yong Ke Jian-xiong Chen Jin-jie Zhou 《第一军医大学学报》2005,25(5):524-527
OBJECTIVE: To observe the selective killing effect of adenovirus (Ad)-mediated double suicide gene driven by kinase domain-containing receptor(KDR) promoter on human colorectal cancer LoVo cells and human umbilical vein endothelial ECV304 cells. METHODS: The plasmid pAdEasy-KDR-CDglyTK was transfected into 293 packaging cells for amplification of the infectious Ad and used to infect the KDR-producing cells (ECV304 and LoVo) and the KDR-nonproducing cells (LS174T) respectively. The three cells were treated with the prodrugs 5-flurocytosine (5-FC) and ganciclovir (GCV) at different concentrations after infection. The killing effects of the fusion gene system on the cells were evaluated. The distribution of cell cycle was detected by flow cytometry. RESULTS: The infection rates of the recombinant Ad were similar among the 3 cells, gradually increasing with the increment of multiplicity of infection (MOI) and reaching 100% with the MOI of 200. The LoVo cells and ECV304 cells infected with Ad-KDR-CDglyTK were highly sensitive to both of the prodrugs (P>0.1), whereas the infected LS174T cells failed to exhibit similar sensitivity (P<0.001). The killing effect of CD/TK fusion gene on the target cells was much stronger than that of either suicide gene (P<0.001). The cell cycle of LoVo cells was arrested at G1 phase. CONCLUSION: The CD/TK fusion gene system driven by KDR promoter can selectively kill KDR-expressing human colorectal cancer LoVo cells and endothelial cells. 相似文献