全文获取类型
收费全文 | 193958篇 |
免费 | 18333篇 |
国内免费 | 12013篇 |
专业分类
耳鼻咽喉 | 1981篇 |
儿科学 | 3052篇 |
妇产科学 | 1172篇 |
基础医学 | 13286篇 |
口腔科学 | 3437篇 |
临床医学 | 23224篇 |
内科学 | 18752篇 |
皮肤病学 | 2123篇 |
神经病学 | 5804篇 |
特种医学 | 8044篇 |
外国民族医学 | 13篇 |
外科学 | 19367篇 |
综合类 | 49840篇 |
现状与发展 | 60篇 |
一般理论 | 4篇 |
预防医学 | 22020篇 |
眼科学 | 2516篇 |
药学 | 22816篇 |
262篇 | |
中国医学 | 17300篇 |
肿瘤学 | 9231篇 |
出版年
2024年 | 905篇 |
2023年 | 2427篇 |
2022年 | 6110篇 |
2021年 | 7909篇 |
2020年 | 6894篇 |
2019年 | 4222篇 |
2018年 | 4388篇 |
2017年 | 5499篇 |
2016年 | 4390篇 |
2015年 | 7719篇 |
2014年 | 9886篇 |
2013年 | 12156篇 |
2012年 | 17616篇 |
2011年 | 18790篇 |
2010年 | 16475篇 |
2009年 | 14606篇 |
2008年 | 15271篇 |
2007年 | 14482篇 |
2006年 | 12938篇 |
2005年 | 10135篇 |
2004年 | 7512篇 |
2003年 | 6380篇 |
2002年 | 4914篇 |
2001年 | 4252篇 |
2000年 | 3246篇 |
1999年 | 1348篇 |
1998年 | 424篇 |
1997年 | 361篇 |
1996年 | 357篇 |
1995年 | 328篇 |
1994年 | 276篇 |
1993年 | 201篇 |
1992年 | 180篇 |
1991年 | 178篇 |
1990年 | 148篇 |
1989年 | 136篇 |
1988年 | 115篇 |
1987年 | 114篇 |
1986年 | 108篇 |
1985年 | 90篇 |
1984年 | 96篇 |
1983年 | 66篇 |
1982年 | 77篇 |
1981年 | 53篇 |
1980年 | 49篇 |
1979年 | 46篇 |
1978年 | 47篇 |
1975年 | 39篇 |
1974年 | 39篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The results of a modified Wilson shaft osteotomy for hallux valgus in 77 feet of 51 patients were excellent or good in 62 feet after 2 to 4 years. The correction of the hallux valgus angle and intermetatarsal angle was excellent or good in 69 feet. The operation is technically simple provided dorsal angulation of the distal fragment is avoided in the early postoperative period.A 相似文献
52.
The chick chorioallantoic membrane was used to determine whether the carotid atherosclerotic plaque stimulates angiogenesis. Carotid endarterectomy specimens (1 mm3) with fibromuscular plaque (n = 8) and complicated plaque (n = 11) were implanted on the membrane on day nine of incubation and the response evaluated on day 11. Following fixation in situ with 10% formalin the angiogenic response was evaluated by: (1) examining whole membrane mounts, (2) quantitatively from a vascular density index and (3) from a histological study. Unmanipulated chorioallantoic membrane (n = 11) and plaque boiled prior to implantation (n = 6) served as controls. The vascularity of whole mounts of both fibromuscular and complicated plaque was greater than the controls. Vessel density of the membrane was estimated by counting the number of vessels intersecting four concentric circles (144.5 mm total circumference) placed on the formalin fixed membrane. The vascular density index due to the fibromuscular plaque (390.6 +/- 8.3) and complicated plaque (391.0 +/- 14.9) were similar (P greater than 0.9) but were significantly greater (P less than 0.001) than the unmanipulated membrane (327.9 +/- 5.6) or after treatment with the boiled plaque (283.8 +/- 15.6). Transforming growth factor beta 1 confirmed the validity of the experimental model to study angiogenesis. The histology of the chorioallantoic membrane due to either type of plaque was similar. Numerous vessels surrounded the plaque, and intraplaque vessels containing nucleated chick erythrocytes were observed. Although scattered vessels surrounded the boiled plaque, intraplaque vessels were not observed. This study demonstrates that the atherosclerotic plaque has angiogenic properties that may account for the increase in vasa vasorum that is associated with the plaque. 相似文献
53.
Jan Lycke Bo Svennerholm Anders Svenningsson Walter Muranyi Rolf M. Flügel Oluf Andersen 《Journal of neurology》1994,241(4):204-209
The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS. 相似文献
54.
目的:建立大鼠颈动脉再狭窄模型,原位灌注固定取材。评价PTA后血管重塑(VR)的动态变化规律,定量分析血管重塑在血管再狭窄过程中的变化及作用。方法:制作70只SD雄性大鼠颈总动脉再狭窄模型,分原位灌注实验组、对照组,于术后1h、3、7、14、28和42天原位灌注固定取材,行HE染色、Masson染色,观察标本血管狭窄情况。结果:①血管重塑指数(VRI)在PTA后即刻最大,3天组明显降低,7天组稍有增大,其后不断减小,剩余血管腔面积百分比同VRI的变化曲线基本一致。②FFA后,血管腔面积总体呈逐渐缩小趋势,内弹力板围绕面积(IELA)1h组较对照组明显增大,3天组较1h组明显缩小,14、28、42天组较对照组明显缩小。外弹力板围绕面积(EELA)逐渐缩小。EELA、IELA的变化与血管腔面积变化呈正相关。③VRI与血管腔面积的变化呈正相关,新生内膜面积与剩余狭窄率、血管腔面积无直线相关。结论:再狭窄过程中存在扩张性重塑和收缩性重塑现象,管腔的狭窄与否取决于血管重塑指数的变化,而不是新生内膜的变化,新生内膜的形成是血管重塑过程中的一部分。IELA和EELA可作为判断管腔狭窄及评价血管重塑的指标。 相似文献
55.
Diagnosis of scaphoid fractures:A prospective multicenter study of 1,052 patients with 160 fractures
Bo Munk Johnny Fr kj r Claus Falck Larsen Hans Gad Johannsen Lars Lundager Rasmussen Annette Edal Lilla Demeney Rasmussen 《Acta orthopaedica》1995,66(4):359-360
In a prospective multicenter study of 1,052 patients with clinical signs of a scaphoid fracture, mammo-graphic films and fine intensifying screens were used at the radiographic examination. 5 standardized projections including 3 special projections focused on the scaphoid were taken. 150 fractures were diagnosed at the first examination but in 10 cases the fracture was first diagnosed at a second radiographic examination after 10-14 days.
The second examination still seems mandatory despite the use of high quality radiographs with optimal spatial resolution and contrast, and the value of supplementary special projections. 相似文献
The second examination still seems mandatory despite the use of high quality radiographs with optimal spatial resolution and contrast, and the value of supplementary special projections. 相似文献
56.
V B Troitskaia G V Marinchenko S A Aganezov N N Artem'eva N V Bo?kova V L Kuznetsov 《Vestnik Rossi?sko? akademii meditsinskikh nauk / Rossi?skaia akademiia meditsinskikh nauk》1992,(11-12):58-61
The experiments were performed on 34 dogs. The subcutaneous injection of boiled pancreatic juice was established to increase the survival of dogs in acute destructive pancreatitis (p < 0.001) and to decrease the specific volume damage to acinar (p < 0.01) and interstitial (p < 0.05) pancreatic tissue. It was also shown that boiled pancreatic autojuice exerted the therapeutic effect in chronic pancreatitis complicated by pancreatic fistulas. Five peptide components with a molecular mass from 4168 D to 1000 were discovered in the canine boiled pancreatic juice by liquid high pressure chromatography. Fractions with a molecular mass between 2187 and 1348 D were found to correspond to biologically active peptides, in particular to somatostatin. It is assumed that the therapeutic effect of boiled pancreatic juice used in acute pancreatitis may be due to somatostatin. Apparently pancreatic juice may turn an efficient therapeutic agent in acute pancreatitis and pancreatic fistulas. 相似文献
57.
Objective To evaluate the bioequivalence between recombinant human growth hormone (rhGH) for reconstitution, and two dosages of liquid formulation of rhGH [ (151U) 5mg or (301U) lOmg per 3ml ]. Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of O. 21U/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The ve- nous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals (CI) of AUC0-24h among three products were all within 80% - 125% interval ( 103. 4% - 116. 5%, 105. 7% - 119. 6% and 91.9% - 103. 7%, respectively), and the Cls of C,~ among three products were all within 70% - 143% interval (91.9% - 114. 0%, 103. 7% -127. 2% and 81.6% -97. 4%, respectively). There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH. 相似文献
58.
Fa-Lin XU Chang-Lian ZHU Xiao-Yang WANG Department of Pediatrics the Third Affiliated Hospital of Zhengzhou University Zhengzhou China 《中国神经科学杂志》2006,(1)
Objective To study the developmental changes of glutamic acid decarboxylase-67 (GAD-67, a GABA synthetic enzyme) in normal and hypoxic ischemic (HI) brain. Methods C57/BL6 mice on postnatal day (P) 5, 9, 21 and 60, corresponding developmentally to premature, term, juvenile and adult human brain were investigated by using both Western blot and immunohistochemistry methods either in normal condition or after hypoxic ischemic insult. Results The immunoreactivity of GAD67 was up regulated with brain development and significant difference was seen between mature (P21, P60) and immature (P5, P9) brain. GAD67 immunoreactivity decreased in the ipsilateral hemisphere in all the ages after hypoxia ischemia (HI) insult, but, significant decrease was only seen in the immature brain. Double labeling of GAD67 and cell death marker, TUNEL, in the cortex at 8h post-HI in the P9 mice showed that (15.6±7.0)% TUNEL positive cells were GAD67 positive which was higher than that of P60 mice. Conclusion These data suggest that GABAergic neurons in immature brain were more vulnerable to HI insult than that of mature brain. 相似文献
59.
Objective To investgate the effects of TGF β 3 on rat hepatic fibrosis. Methods The TGF β 3 cDNA was cloned into rAAV2 vector. Rats were randomly divided into four groups: normal control group, model group, negative control group and TGF β 3 group. Hepatic fibrosis was induced by hypodermic injection of 40% CCI4. Recombinant AAV2-TGF β 3 viral particles were injected via the vena caudalis one week before CCh treatment. Rats were executed 8 weeks after CCI4 treatment, global histological change was observed after HE staining, the distribution of the collagen fibers was observed after masson staining, his-tochemistry was done to observe the expression of collagen Ⅰ; The positive area rate of the collagen fibers and the average optical rate of collagen Ⅰ were quantified. Results HE staining indicated that collagen fibers were reduced in the TGF β 3 group. Masson staining shown that the collagen fibers were distributed around the blood vessel, in the portal area and disse space. Compared to the model group (13.2%±2.2%) and negative control group (12.3%±1.5%), the collagen fibers in liver tissues of TGF β3 group (7.7% ± 1.5%) were significantly decreased (q = 9.456, P < 0.01; q = 8.217, P < 0.01). Histochemistry indicated that the collagen fibers of liver tissues of TGF 15 3 group (0.185±0.033) were significantly higher than those in the model group (0.252±0.042) and the negative control group (0.230±0.029), (q = 6.228, P < 0.01; q = 4.346, P < 0.01). Conclusion TGF β 3 alleviates the damage to hepatic cell and the level offibrosis in CCI4 treated rats and inhibits the expression of collagen Ⅰ. 相似文献
60.
目的:评价口服水剂、水灌肠及两者联合应用充盈肠道后,使用MSCT显示成人正常肠道的能力。材料和方法:将43名非肠道病变志愿者分别采用口服水剂法(21例)、水灌肠法(12例)、双重法(口服水剂和水灌肠联合应用,10例)充盈肠道,然后行MSCT平扫和增强扫描并进行图像重建,对小肠和大肠各肠段充盈状态进行评价。结果:口服水剂法回肠充盈良好,水灌肠法大肠充盈良好,双重法回肠及大肠均充盈良好。口服水剂法小肠充盈优于水灌肠法,与双重法无显著差异,大肠充盈状态水灌肠法明显优于口服水剂法,与双重法无显著差异。结论:口服水剂和水灌肠联合应用可以在MSCT同时较好地充盈显示小肠和大肠,而两种方法单独使用则仅能分别充盈显示小肠和大肠,需要根据显示目的选择相应的充盈方法。 相似文献