全文获取类型
收费全文 | 1233篇 |
免费 | 137篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 69篇 |
儿科学 | 67篇 |
妇产科学 | 33篇 |
基础医学 | 162篇 |
口腔科学 | 46篇 |
临床医学 | 171篇 |
内科学 | 243篇 |
皮肤病学 | 21篇 |
神经病学 | 69篇 |
特种医学 | 102篇 |
外科学 | 143篇 |
综合类 | 31篇 |
预防医学 | 64篇 |
眼科学 | 39篇 |
药学 | 74篇 |
肿瘤学 | 41篇 |
出版年
2022年 | 11篇 |
2021年 | 29篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 36篇 |
2013年 | 56篇 |
2012年 | 44篇 |
2011年 | 54篇 |
2010年 | 58篇 |
2009年 | 48篇 |
2008年 | 38篇 |
2007年 | 50篇 |
2006年 | 43篇 |
2005年 | 46篇 |
2004年 | 34篇 |
2003年 | 30篇 |
2002年 | 36篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 26篇 |
1998年 | 34篇 |
1997年 | 45篇 |
1996年 | 43篇 |
1995年 | 32篇 |
1994年 | 21篇 |
1993年 | 23篇 |
1992年 | 26篇 |
1991年 | 16篇 |
1990年 | 17篇 |
1989年 | 31篇 |
1988年 | 25篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 19篇 |
1980年 | 9篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1976年 | 9篇 |
1971年 | 8篇 |
1970年 | 7篇 |
1969年 | 11篇 |
1967年 | 7篇 |
排序方式: 共有1375条查询结果,搜索用时 15 毫秒
1.
A Ascari-Raccagni†‡ MG Righini† 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):514-516
BACKGROUND: Repairing dorsal nasal defects is a frequent challenge for dermatologic surgeons, mainly due to the high frequency of basal cell carcinomas on this site. Obvious scars, mismatched skin and distortion of the nasal contour are the surgical hazards that must be avoided in these cases. AIM: Our aim was to perform surgery involving a simple flap in order to repair medium to large defects on the dorsal side of the nose. METHODS: The dorsal horizontal advancement flap was studied in 12 patients, in order to evaluate the benefits and limits of this surgical procedure. RESULTS: The resulting scars on most of our patients were well-camouflaged among their natural skin lines, and there was neither distortion of the alar contour nor the nostril. CONCLUSIONS: This flap is easy to perform and, in selected cases, provides an outstanding alternative to second-intention healing, full-thickness skin grafts, transposition, rotation and pedicle flaps. 相似文献
2.
Sandra Urdaneta Hartmann Brian Wigdahl Elizabeth B Neely Cheston M Berlin Cara-Lynne Schengrund Hung-Mo Lin Mary K Howett 《Journal of human lactation》2006,22(1):61-74
Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk. 相似文献
3.
4.
BACKGROUND & AIMS: Nutrients and properties of lipases affect survival of lipolytic activity during aboral gastrointestinal transit. Whether different doses and formulations of bacterial lipase and diets affect steatorrhea was tested in pancreatic-insufficient dogs. METHODS: A dose of 0-600,000 IU of powdered and 135,000 and 300,000 IU of liquid bacterial lipase was given with a standard meal to 5 dogs with ligated pancreatic ducts. In 4 dogs, 0 or 300,000 IU (normal 6-hour postprandial amount) of powder bacterial lipase was also given with five meals containing 850 kcal with different nutrient caloric densities (mixture design). Coefficients of fat absorption during 72- hour fecal balance studies were used to assess treatments. RESULTS: With the standard meal, powder bacterial lipase reduced steatorrhea in a dose-dependent manner (P = 0.03), and 135,000 and 300,000 IU of the liquid form decreased steatorrhea more than powder bacterial lipase (P = 0.017 and 0.057, respectively). Coefficients of fat absorption with 300,000 IU of powder bacterial lipase correlated (r2 = 0.79; P < 0.001) with increasing proportions of fat calories in diets. CONCLUSIONS: Liquid bacterial lipase decreases steatorrhea more than powder, and 300,000 IU of powder bacterial lipase ingested with high-fat meals corrects canine pancreatic steatorrhea. The combination of adequate mixing of small amounts (milligrams) of bacterial lipase and high-fat meals abolishes canine steatorrhea and may abolish human pancreatic steatorrhea. (Gastroenterology 1997 Jun;112(6):2048-55) 相似文献
5.
6.
7.
The proteolytic environment in which Candida albicans exists strongly affects its virulence. To determine whether virulence might be related to C. albicans growth in different proteolytic environments, we measured renal fungal load in burned mice and found significantly greater Candida census in kidneys from mice that were challenged with a high proteinase-generating parent C. albicans (MY 1044) versus those that were challenged with its low proteinase-generating mutant (MY 1049). In vitro, MY 1044 cells grew faster than MY 1049 cells in media that contained sera from burned mice as the only nitrogen source. Augmentation of media with proteinase or a mixture of amino acids increased growth of MY 1049 cells, whereas augmentation with proteinase inhibitor decreased MY 1044 growth. In conclusion, in vitro growth of both the mutant and its parent strain was affected by the proteolytic environment in which they existed; thus, virulence differences for MY 1044 and MY 1049 could be due in part to growth differences between these two strains in different proteolytic environments. These results were combined with existing observations, and we proposed a theory for the pathogenesis of C. albicans in burns. 相似文献
8.
TP Amadeu† AB Seabra‡ MG de Oliveira‡ AMA Costa† 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):629-637
BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization. 相似文献
9.
Normal and diseased isolated lungs: high-resolution CT 总被引:8,自引:0,他引:8
10.
Anthony L. Neely 《Journal of clinical periodontology》1992,19(6):367-372
A cross-sectional radiographic screening was performed on bite-wing pairs (BW) from 1872 10-12 year old schoolchildren in the Greater Worcester, Massachusetts area to assess the prevalence of juvenile periodontitis (JP). The 3-stage screening process entailed: (1) visual identification of possible cases based upon a visual assessment of BW for interproximal crestal bone levels greater than or equal to 2 mm from the cemento-enamel junction (CEJ) on greater than or equal to 1 permanent first molar; (2) identification of probable cases based upon BW from possible cases measured with a transparent ruler calibrated in millimeters; (3) finally, clinical confirmation of JP in consenting probable cases. A total of 1038 subjects were eligible to be included in the study (greater than or equal to 3 mesial sites readable). Of the 1038 eligible subjects, 117 possible and 103 probable cases were identified in stage 1 and stage 2, respectively. A total of 99 probable cases could be contacted and 43 were examined clinically. Two cases of JP were confirmed clinically in stage 3, yielding a prevalence rate of 4.6/1000. Specifically, this report defines a rate of JP in 10-12 year-old schoolchildren for the first time. In addition, these results indicate that BW can be used to identify children with JP from large data sets. However, further studies including complete clinical and radiographic examinations are necessary to determine whether this method is adequate for large epidemiologic studies. 相似文献