全文获取类型
收费全文 | 9872篇 |
免费 | 552篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 187篇 |
妇产科学 | 182篇 |
基础医学 | 1313篇 |
口腔科学 | 457篇 |
临床医学 | 817篇 |
内科学 | 2671篇 |
皮肤病学 | 258篇 |
神经病学 | 1006篇 |
特种医学 | 300篇 |
外科学 | 1198篇 |
综合类 | 26篇 |
一般理论 | 2篇 |
预防医学 | 461篇 |
眼科学 | 132篇 |
药学 | 566篇 |
中国医学 | 27篇 |
肿瘤学 | 820篇 |
出版年
2024年 | 9篇 |
2023年 | 72篇 |
2022年 | 153篇 |
2021年 | 294篇 |
2020年 | 159篇 |
2019年 | 233篇 |
2018年 | 277篇 |
2017年 | 221篇 |
2016年 | 225篇 |
2015年 | 280篇 |
2014年 | 390篇 |
2013年 | 479篇 |
2012年 | 770篇 |
2011年 | 794篇 |
2010年 | 413篇 |
2009年 | 380篇 |
2008年 | 659篇 |
2007年 | 677篇 |
2006年 | 599篇 |
2005年 | 648篇 |
2004年 | 554篇 |
2003年 | 499篇 |
2002年 | 480篇 |
2001年 | 102篇 |
2000年 | 89篇 |
1999年 | 93篇 |
1998年 | 108篇 |
1997年 | 74篇 |
1996年 | 74篇 |
1995年 | 68篇 |
1994年 | 59篇 |
1993年 | 40篇 |
1992年 | 49篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 45篇 |
1988年 | 32篇 |
1987年 | 35篇 |
1986年 | 36篇 |
1985年 | 24篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 19篇 |
1981年 | 8篇 |
1980年 | 18篇 |
1979年 | 9篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1970年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The computed tomographic (CT) findings of a right and left paraduodenal hernia are described. In the right paraduodenal hernia the major findings consist of encapsulation of small bowel loops in the right mid-abdomen with looping of arterial and venous jejunal branches behind the superior mesenteric artery. The findings of the left paraduodenal hernia are less specific and involve encapsulation of bowel loops at or above the level of the ligament of Treitz with intermittent dilatation. 相似文献
12.
13.
Giovanni Marchetto Andrea M. D'Armini Mauro Rinaldi Mario Vigan 《European journal of cardio-thoracic surgery》2005,27(6):1122-1124
Video-assisted minimally invasive cardiac surgery (VAMICS) is currently performed with various indications. However, despite the increasing evidence of its effectiveness, new approaches have to be defined to simplify this procedure, minimize its potential complications and limit its costs, for a wider use in the surgical community. The limited access to the aorta is a key point in VAMICS and mandates specific clamping modalities with their own limitations, costs and drawbacks. The Portaclamp (Cardio Life Research SA, Louvain la Neuve, Belgium), a new autoguided extravascular aortic cross-clamping system, has been recently proposed to facilitate VAMICS. Herein, we describe the Portaclamp approach and report our indications and preliminary clinical experience so to define its role in VAMICS. 相似文献
14.
15.
Gaetano Guerra Francesco Dal Poggetto Mauro Iuliano Carla Manfredi 《Macromolecular chemistry and physics.》1992,193(9):2413-2420
Infrared spectra of syndiotactic poly(p-methylstyrene) (s-PPMS) samples, exhibiting various crystalline forms and clathrate structures, are reported in this contribution. Bands due to the syndiotactic stereostructure, bands typical of the two different chain conformations observed in the crystalline structures and bands sensitive to intermolecular interactions typical of the different modes of packing of chains are pointed out. The observed similarities with the case of syndiotactic polystyrene are alos indicated. A complete assignment, via FTIR analysis, of the chain conformations, is presented for all the known crystalline forms and clathrates of s-PPMS. 相似文献
16.
Andrea Giustina Angela Girelli Danlele Albert Simonetta Bossonl Fabio Buzl† Mauro Doga Maurlzlo Schettino William B. Wehrenberg‡ 《Clinical endocrinology》1991,35(6):491-498
OBJECTIVES: We aimed to investigate both nocturnal spontaneous and morning growth hormone (GH)-releasing hormone (GHRH)-induced GH secretion in children on daily glucocorticoid treatment after liver transplantation and to evaluate the effect of pyridostigmine (an acetylcholinesterase inhibitor thought to reduce hypothalamic somatostatin tone) on GH secretion in these patients. DESIGN: We performed a randomized, single-blind, cross-over study. PATIENTS: We studied three male and three female juvenile patients, within a year of orthotopic liver transplantation and under immunosuppressive glucocorticoid therapy (mean dose +/- SEM, 5.92 +/- 0.63 mg/day) and five normal children (four males, one female). MEASUREMENTS: Both nocturnal spontaneous and morning GHRH-induced GH secretion were evaluated after administration of placebo, 1 tablet p.o., or pyridostigmine, 2 mg/kg p.o. RESULTS: Spontaneous GH. Placebo: in liver transplanted children nocturnal GH secretion (mean GH level 10.8 +/- 2.0 mU/l) was not significantly different with respect to normal children (mean GH level 12.8 +/- 1.2 mU/l); pyridostigmine: nocturnal GH secretion was significantly increased as compared to placebo in subjects with liver transplantation but not in normal children. GHRH test. Placebo: liver transplanted patients showed a blunted GH response to GHRH with respect to normal children; pyridostigmine: the GH responses to GHRH (P less than 0.05) increased as compared to placebo and did not differ significantly in the two groups. CONCLUSIONS: Our data suggest a steroid-mediated increase in hypothalamic somatostatin tone in liver transplanted children. 相似文献
17.
Mauro Rubini Silvia Mogliazza Robert Spencer T Corruccini 《American journal of human biology》2007,19(1):119-131
The frequencies of nine discrete cranial traits are contrasted among 10 skeletal series of central Italy to assess the patterning of biological affinity or divergence. In this study various statistical applications were used: Mean Measure of Divergence (MMD), which was elaborated using the WPGMA cluster analysis, neighbor-joining method and principal coordinate analysis. The results show two main groups divided by the Apennines, which probably were a geographic barrier to biological exchange during the Italian Iron Age. This fact induced endogamous phenomena in the populations on the two sides of Italy (Adriatic and Tyrrenian) and probably increased the familial segregation of traits. The group on the western side has a further division between samples of the central coast and those of the southern coast. The latter samples seem to be more closely connected to Sardinian peoples, and this indicates gene flow and cultural contacts, which were not hindered by the sea. This segregation appears to have receded by Roman times. 相似文献
18.
Alessia Bacchi Mauro Carcelli Giancarlo Pelizzi Paola Vicini 《Archiv der Pharmazie》1995,328(3):217-221
The amino/imino equilibrium is studied in free bases and hydrochloride salts of amidinobenzisothiazole derivatives by IR and 1H-NMR spectroscopy. The X-ray crystallographic analysis of two of these compounds shows that the free base exists as amino form whereas the hydrochloride as imino form. 相似文献
19.
An 11-year clinical evaluation of leucite-reinforced glass-ceramic crowns: a retrospective study. 总被引:5,自引:0,他引:5
OBJECTIVE: The purpose of this study was to retrospectively evaluate leucite-reinforced glass-ceramic crowns placed over a 6-year period at two different private dental practices. METHOD AND MATERIALS: One hundred twenty-five Empress crowns were placed in 54 patients. The 93 anterior and 32 posterior crowns were evaluated clinically with a mirror and probe, radiographically, and from clinical photographs, in accordance with a modified California Dental Association and Ryge quality evaluation system. The risk of fracture was determined with the Kaplan-Meier survival analysis. RESULTS: Crowns were studied over periods ranging from 4 to 11 years. The probability of survival of the 125 crowns was 95.2% at 11 years (98.9% in the anterior segment and 84.4% in the posterior segment). Six crowns had to be replaced. Most of the 119 successful crowns were rated excellent; Alfa ratings were assigned to 94.2% for color match, 91.6% for porcelain surface, 86.6% for marginal discoloration, and 94.2% for marginal integrity. CONCLUSION: Leucite-reinforced glass-ceramic crowns showed a low clinical failure rate and excellent esthetics after up to 11 years. 相似文献
20.
M A Mauro L A Parker W S Hartley J B Renner P M Mauro 《AJR. American journal of roentgenology》1987,149(5):925-927
Epidermolysis bullosa is a group of dermatologic disorders with varied inheritance patterns having the common manifestation of blister or bulla formation after minor trauma. Sixteen patients with the disease had the following radiographic manifestations: esophageal stricture (16), fecal impaction (six), vaginal stenosis (one), epithelial bridging and fusion of the digits (six), and aspiration changes in the lungs (two). Esophageal strictures involved the pharynx or cervical esophagus in eight cases and were multiple in five; they ranged in length from 2 mm to 15 cm and tended to progress over time. The findings of esophageal stricture, particularly when multiple and involving the proximal esophagus, and/or the presence of distal phalangeal atrophy with soft-tissue webbing suggest the diagnosis of epidermolysis bullosa. 相似文献