全文获取类型
收费全文 | 2642058篇 |
免费 | 199624篇 |
国内免费 | 4992篇 |
专业分类
耳鼻咽喉 | 37826篇 |
儿科学 | 84071篇 |
妇产科学 | 76164篇 |
基础医学 | 371704篇 |
口腔科学 | 79687篇 |
临床医学 | 229812篇 |
内科学 | 512857篇 |
皮肤病学 | 58430篇 |
神经病学 | 213000篇 |
特种医学 | 105447篇 |
外国民族医学 | 879篇 |
外科学 | 404474篇 |
综合类 | 64446篇 |
现状与发展 | 9篇 |
一般理论 | 926篇 |
预防医学 | 196352篇 |
眼科学 | 62175篇 |
药学 | 199681篇 |
7篇 | |
中国医学 | 5390篇 |
肿瘤学 | 143337篇 |
出版年
2018年 | 24149篇 |
2015年 | 24308篇 |
2014年 | 33762篇 |
2013年 | 51802篇 |
2012年 | 68891篇 |
2011年 | 72778篇 |
2010年 | 43199篇 |
2009年 | 41371篇 |
2008年 | 69904篇 |
2007年 | 74786篇 |
2006年 | 75765篇 |
2005年 | 73661篇 |
2004年 | 72131篇 |
2003年 | 69529篇 |
2002年 | 68345篇 |
2001年 | 122430篇 |
2000年 | 126166篇 |
1999年 | 107467篇 |
1998年 | 29327篇 |
1997年 | 26669篇 |
1996年 | 26146篇 |
1995年 | 25137篇 |
1994年 | 23626篇 |
1993年 | 22172篇 |
1992年 | 86659篇 |
1991年 | 84016篇 |
1990年 | 82274篇 |
1989年 | 80158篇 |
1988年 | 74616篇 |
1987年 | 73469篇 |
1986年 | 70138篇 |
1985年 | 67296篇 |
1984年 | 50428篇 |
1983年 | 43279篇 |
1982年 | 25697篇 |
1981年 | 23245篇 |
1980年 | 21778篇 |
1979年 | 48332篇 |
1978年 | 34082篇 |
1977年 | 29091篇 |
1976年 | 26859篇 |
1975年 | 29340篇 |
1974年 | 35519篇 |
1973年 | 34249篇 |
1972年 | 32080篇 |
1971年 | 30147篇 |
1970年 | 28164篇 |
1969年 | 26775篇 |
1968年 | 24871篇 |
1967年 | 22406篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Effectiveness and nutritional consequences of amino acid-based vs glucose-based dialysis solutions in infants and children receiving CAPD 总被引:2,自引:0,他引:2
Excessive glucose absorption and dialysate amino acid and protein losses contribute to malnutrition in children on glucose-based continuous ambulatory peritoneal dialysis (CAPD). We used 2.5 and 4.25% glucose and 1.1 and 2.0% amino acid dialysates to assess short-term effectiveness and nutritional consequences of amino acid-based dialysis solutions. Plasma and effluent urea and creatinine concentrations were similar with amino acid and glucose dialysis although 16% less fluid was removed with amino acid dialysates. Absorption of 77.3 +/- 5.3% of dialysate amino acids exceeded losses of amino acids and protein in glucose effluent. With amino acid dialysates, fasting plasma glucose concentrations were maintained while plasma amino acid levels rose, peaked at 1 h, and, excepting methionine, isoleucine, and phenylalanine with the 2.0% solution, returned to initial levels after 5 h. Compared with glucose, amino acid dialysates provide reduced but satisfactory fluid and waste removal, maintain normoglycemia, and more than compensate for effluent losses of amino acids and protein. 相似文献
952.
953.
Rifampin alone or with trimethoprim for contacts of children with Haemophilus influenzae type b infections. 总被引:1,自引:0,他引:1 下载免费PDF全文
T Jadavji R Cheung R M Bannatyne C G Prober 《Canadian Medical Association journal》1986,135(4):328-331
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days. 相似文献
954.
955.
K Junge U Klinge B Klosterhalfen P R Mertens R Rosch A Schachtrupp F Ulmer V Schumpelick 《Journal of investigative surgery》2002,15(6):319-328
Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material. 相似文献
956.
957.
OBJECTIVES: solders containing chromophores and proteins enhance the strength of lasered anastomoses. Methylene blue (MB) solder anastomoses in vitro are strong but no in vivo work has been reported. We used an MB solder in vivo and studied the effects of two laser powers on patency and histological appearance. DESIGN, MATERIALS AND METHODS: two groups of 15 rabbits had unilateral end-to-end carotid anastomoses (1.5-2.0 mm) formed using three stay sutures and MB solder. Group 1 anastomoses were formed at 5.7 Wcm(-1) and Group 2 at 2.8 Wcm(-1). The vessels were examined at various points by necropsy for patency and gross macroscopic appearance, with subsequent histological examination. RESULTS: group 2 showed patency of 93.3% v 0% ( p<0.001) endothelialisation of 100% v 26.6% ( p<0.001), giant cell formation 0% v 40.0% ( p<0.01), but stenosis was not significantly different (0% v 13.3% p=0.06). Group 2 showed a higher rate of intimal hyperplasia (IH) (66.6% v 20.0% p<0.05) but neither group exhibited thermal injury or aneurysm formation. CONCLUSIONS: laser soldered microvascular anastomoses were formed in vessels of 1.5-2.0 mm with a high degree of patency. A relationship appears to exist between laser power and anastomotic patency. Methylene blue fading has the potential to act as a switch against over exposure and a visual indicator of solder activation. 相似文献
958.
Physiologic mechanism and preoperative prediction of new-onset dysphagia after laparoscopic Nissen fundoplication 总被引:2,自引:0,他引:2
Dennis Blom M.D. Jeffrey H. Peters M.D. Tom R. DeMeester M.D. Peter F. Crookes M.D. Jeffrey A. Hagan M.D. Steven R. DeMeester M.D. Cedric Bremner M.D. 《Journal of gastrointestinal surgery》2002,6(1):22-28
The aim of this study was to determine whether preoperative physiologic factors can account for and be used to predict the
development of postoperative dysphagia after laparoscopic Nissen fundoplication. One hundred sixty-three patients with gastroesophageal
reflux disease underwent laparoscopic Nissen fundoplication with a median follow-up of 14 months (range 6 to 81 months). Preoperative
dysphagia was present in 37% (60 of 163) and was relieved in all but five patients (92%). Female sex (P = 0.01) and the presence of a stricture (P = 0.02) were the only preoperative variables associated with the presence of preoperative dysphagia. Eight percent (8 of
103) of patients without preoperative dysphagia developed new-onset dysphagia, and of these 63% (5 of 8) had a normal lower
esophageal sphincter (LES) (pressure >6 mm Hg; length >2 cm; abdominal length >1 cm). New-onset dysphagia was significantly
more common in patients with a normal LES (22% [5 of 23] vs. 4% [3 of 80], P = 001). Patients with a normal LES had almost a sixfold increase in the risk of developing dysphagia as those with an abnormal
LES (relative risk = 5.8). Only a preoperative normal LES (P = 0.02) or mean LES pressures (P = 0.04) were positively associated with the development of postoperative dysphagia. The severity of this dysphagia also showed
a strong positive trend of increasing with mean preoperative LES pressures (P = 0.07). Finally, preoperative LES pressure significantly correlated with postoperative LES pressure (r = 0.48, P = 0.01) and with mean residual LES (nadir) pressure (r = 0.33, P = 0.05) offering insight into the mechanism of this dysphagia. In conclusion, preoperative LES parameters play a role in
the development of dysphagia after laparoscopic Nissen fundoplication. Patients with a normal LES or high mean LES pressures
are at increased risk for developing this complication and should be informed of this before laparoscopic Nissen fundoplication.
Presented at the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Ga., May 20–23,
2001. 相似文献
959.
Tilmann Krackhardt Dankwart Höntzsch Uwe Ochs Kuno Weise 《Trauma und Berufskrankheit》2002,4(4):383-387
The small external fixator can be used in the treatment of injuries of the wrist and the distal forearm.This fixator is indicated especially when an unstable fracture needs to be treated, when the bone concerned is affected by osteoporosis in an elderly patient,and in the early treatment of polytraumatized patients with severe soft tissue injuries.For reduction of the fracture we prefer the modular three-tube technique, which is very gentle on the soft tissue; in addition we use the advantages of ligamentotaxis.Depending on the fracture type,we use the small external fixator alone or in association with an internal osteosynthesis.With scrupulous followup checks in the outpatient clinic loosening of the Schanz screws and infection around them are very rare. 相似文献
960.
The study of the effects of morphogenesis at puberty on the Leydig cells in the testis of the young hedgehog and of the subsequent changes due to the seasonal varisations, has been done. Furthermore, the restorative changes induced by the exogenous hormones in the Leydig cells and the related sex organs of the regressed hedgehogs have also been studied. It was observed that the Leydig cells from the undifferentiated mesenchyme cell-like nature in the young hedgehog, develop into an adult form possessing large number of lipids, a well-developed Golgi apparatus, complex mitochondria and extensive smooth endoplasmic reticulum. The depletion of the lipids and other regression associated changes are found in the interstitial Leydig cells but not in those situated under tunica albuginea and the latter probably function as lipid storing cells during regression. Pituitary extract, either alone or in combination, but not testosterone, could restore completely the structure of the regressed Leydig cells. Similarly, the restoration of the complete process of spermatogenesis and the structure and function of the epididymis in the regressed hedgehog was found to be dependent upon the synergistic action of both testosterone and the gonadotrophic hormones. 相似文献