全文获取类型
收费全文 | 876篇 |
免费 | 56篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 29篇 |
妇产科学 | 7篇 |
基础医学 | 97篇 |
口腔科学 | 19篇 |
临床医学 | 88篇 |
内科学 | 300篇 |
皮肤病学 | 16篇 |
神经病学 | 14篇 |
特种医学 | 167篇 |
外科学 | 84篇 |
综合类 | 28篇 |
预防医学 | 22篇 |
眼科学 | 5篇 |
药学 | 60篇 |
肿瘤学 | 33篇 |
出版年
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 11篇 |
2018年 | 16篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 15篇 |
2014年 | 20篇 |
2013年 | 14篇 |
2012年 | 20篇 |
2011年 | 25篇 |
2010年 | 24篇 |
2009年 | 36篇 |
2008年 | 24篇 |
2007年 | 42篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 19篇 |
2000年 | 21篇 |
1999年 | 22篇 |
1998年 | 52篇 |
1997年 | 45篇 |
1996年 | 39篇 |
1995年 | 29篇 |
1994年 | 23篇 |
1993年 | 33篇 |
1992年 | 16篇 |
1991年 | 17篇 |
1990年 | 12篇 |
1989年 | 38篇 |
1988年 | 24篇 |
1987年 | 27篇 |
1986年 | 18篇 |
1985年 | 24篇 |
1984年 | 20篇 |
1983年 | 20篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1980年 | 18篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有971条查询结果,搜索用时 0 毫秒
91.
目的:对长期以来关于骨纤维结构不良大量相关研究及文献进行回顾,综述骨纤维结构不良的诊断和治疗的最新进展。资料来源:通过计算机互联网检索OVID数据库1966-01/2006-10关于骨纤维结构不良的文献,检索词:Osteofibrous dysplasia,限定语言种类为English。同时检索1994-01/2006-10中国全文期刊数据库有关骨纤维结构不良的文献,检索词为:骨纤维结构不良,限定语言种类为中文。资料选择:选择与骨纤维结构不良相关的观察对比研究、经验总结、个案报道、最新研究进展等文献,力求资料全面,排除重复研究。资料提炼:共收集相关国内外文献41篇,排除重复性研究11篇,采用30篇,包括关于骨纤维结构不良定义、发病机制、病理、诊断及治疗等。资料综合:①骨纤维结构不良是一种起源于纤维组织的良性骨肿瘤。发病率低、误诊率高。目前具体发病机制不明,现认为与常染色体显性遗传有关。②骨纤维结构不良好发于胫骨,症状为局部肿块。特征性影像学表现为胫骨中段前侧皮质膨胀性密度减低。确诊方法为病理检查。重点与骨纤维异常增殖症、造釉细胞瘤相鉴别,现有大量研究证明该病与造釉细胞瘤有联系。③治疗上过去认为10岁以前应保守治疗,10岁后选择手术治疗,目前倾向于早期骨膜外切除手术治疗。结论:骨纤维结构不良发病率低,对该病认识较少,误诊率较高,重点需与骨纤维异常增殖症、造釉细胞瘤相鉴别,应提高对该病的认识与重视程度,对可疑者行病理检查,确诊者行骨膜外切除,切除范围较大的病例行重建手术。 相似文献
92.
93.
FcR gamma-chain is essential for both surface expression and function of human Fc gamma RI (CD64) in vivo 总被引:5,自引:0,他引:5
van Vugt MJ; Heijnen AF; Capel PJ; Park SY; Ra C; Saito T; Verbeek JS; van de Winkel JG 《Blood》1996,87(9):3593-3599
Most Ig receptors exist as hetero-oligomeric complexes with separate ligand binding (alpha) and signal transducing (beta, gamma, or zeta) subunits. For Fc gamma RIIIa and Fc epsilon RI, association with the FcR gamma-chain is essential for surface expression. However, the human high affinity IgG receptor, hFc gamma RI, was found to be surface- expressed by itself in transient transfection models. We have now analyzed the integrity of hFc gamma RI expression in more detail in stable transfectants. In vitro we noted that, in the absence of FcR gamma-chain, surface expression of hFc gamma RI rapidly declined to background levels, in both IIA1.6 B cells and NIH3T3 fibroblasts. The effect of FcR gamma-chain on hFc gamma RI surface expression in vivo was evaluated by using two newly generated transgenic mouse lines, selectively expressing hFc gamma RI on myeloid cells. These transgenic mice were crossed with FcR gamma-chain-deficient mice. Analysis of blood monocytes and peritoneal macrophages showed that surface expression of hFc gamma RI was reduced by approximately 80%. The remaining approximately 20% of receptors were still capable of binding IgG-opsonized RBC, suggesting FcR gamma-chain not to be critical for hFc gamma RI ligand-binding capacity. Importantly, however, hFc gamma RI signaling capacity was lost in FcR gamma-chain-deficient cells. No phagocytosis could be observed using either ligand sensitized (EA- IgG2a) or CD64-targeted erythrocytes (using a bispecific antibody) in both hFc gamma RI transgenic lines. This documents the FcR gamma-chain to be indispensable for both surface membrane expression and function of human Fc gamma RI in vivo. 相似文献
94.
Background
Pressure ulcers are a common, painful and costly condition. Results of a 1991 study into the knowledge among Dutch hospital nurses on the usefulness of measures to prevent pressure ulcers showed moderate knowledge. Results were confirmed by subsequent studies. In recent years, Dutch guidelines have been updated and the attention given to pressure ulcer care has been increased. This was expected to improve pressure ulcer care and to increase nurses' knowledge. The aims of the current study were to investigate (1) how much nurses employed in Dutch hospitals know about the usefulness of 28 preventive measures considered in the most recent national pressure ulcer guideline; (2) whether differences in knowledge exist between nurses working in hospitals that audit pressure ulcers and those employed in hospitals that do not; and (3) to study whether knowledge among Dutch hospital nurses regarding the usefulness of preventive measures had changed between 1991 and 2003. 相似文献95.
96.
Background and purpose:
The sarcoplasmic reticulum (SR), regulates the cytoplasmic Ca2+ concentration ([Ca2+]cyto) in vascular smooth muscle. Release from the SR is controlled by two intracellular receptor/channel complexes, the ryanodine receptor (RyR) and the inositol 1,4,5-trisphosphate receptor (IP3R). These receptors may be regulated by the accessory FK506-binding protein (FKBP) either directly, by binding to the channel, or indirectly via FKBP modulation of two targets, the phosphatase, calcineurin or the kinase, mammalian target of rapamycin (mTOR).Experimental approach:
Single portal vein myocytes were voltage-clamped in whole cell configuration and [Ca2+]cyto measured using fluo-3. IP3Rs were activated by photolysis of caged IP3 and RyRs activated by hydrostatic application of caffeine.Key results:
FK506 which displaces FKBP from each receptor (to inhibit calcineurin) increased the [Ca2+]cyto rise evoked by activation of either RyR or IP3R. Rapamycin which displaces FKBP (to inhibit mTOR) also increased the amplitude of the caffeine-evoked, but reduced the IP3-evoked [Ca2+]cyto rise. None of the phosphatase inhibitors, cypermethrin, okadaic acid or calcineurin inhibitory peptide, altered either caffeine- or IP3-evoked [Ca2+]cyto release; calcineurin did not contribute to FK506-mediated potentiation of RyR- or IP3R-mediated Ca2+ release. The mTOR inhibitor , like rapamycin, decreased IP3-evoked Ca2+ release. LY294002Conclusions and implications:
Ca2+ release in portal vein myocytes, via RyR, was modulated directly by FKBP binding to the channel; neither calcineurin nor mTOR contributed to this regulation. However, IP3R-mediated Ca2+ release, while also modulated directly by FKBP may be additionally regulated by mTOR. Rapamycin inhibition of IP3-mediated Ca2+ release may be explained by mTOR inhibition. 相似文献97.
98.
Meireles OR Kantsevoy SV Assumpcao LR Magno P Dray X Giday SA Kalloo AN Hanly EJ Marohn MR 《Surgical endoscopy》2008,22(7):1609-1613
Background Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic
surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of
the gastrotomy incision in a porcine model.
Methods A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced
into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was
advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic
grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler
to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure,
the animals were killed for a study of closure adequacy.
Results Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties
mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem
examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but
the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler
loads with a cutting blade. In the three remaining animals (pigs 2–4), we were able to achieve a full-thickness closure of
the gastric wall incision without any complications.
Conclusions The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further
survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal
interventions.
Presented in part at the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Annual Meeting, Las Vegas, Nevada,
April 2007. 相似文献
99.
100.