全文获取类型
收费全文 | 340篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 9篇 |
妇产科学 | 18篇 |
基础医学 | 49篇 |
口腔科学 | 9篇 |
临床医学 | 36篇 |
内科学 | 73篇 |
皮肤病学 | 3篇 |
神经病学 | 12篇 |
特种医学 | 60篇 |
外科学 | 26篇 |
综合类 | 13篇 |
预防医学 | 12篇 |
眼科学 | 1篇 |
药学 | 12篇 |
中国医学 | 3篇 |
肿瘤学 | 17篇 |
出版年
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 6篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 27篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 18篇 |
1994年 | 7篇 |
1993年 | 18篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 6篇 |
1956年 | 4篇 |
1955年 | 4篇 |
1954年 | 5篇 |
1950年 | 2篇 |
排序方式: 共有361条查询结果,搜索用时 15 毫秒
1.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence. 相似文献
2.
3.
F. R. VOGELPOEL R. J. VAN KOOIJ E. R. TE VELDE J. VERHOEF 《International journal of andrology》1990,13(2):81-86
Isolated sperm from normo-, oligo- and astheno-spermic men were incubated for 20 h in medium supplemented with 8% heat-inactivated or untreated human serum, and in medium with heated or untreated serum deficient in complement factor C3. Before and after incubation, sperm motility was assessed by means of a computer-assisted semen analyser. The results did not show significant differences between the motility of sperm incubated in heated or untreated serum. It is concluded that heating of homologous serum is not necessary for preserving sperm motility and in some cases may even be disadvantageous. 相似文献
4.
Z.M. Scholefield J.r Hassell L. West P. Govindraj J.T. Hecht G. Rushton R. Oldershaw T. Hardingham C.L.R. Merry J.T. Gallagher 《International journal of experimental pathology》2004,85(4):A73-A74
Introduction Heparin sulfate (HS) has long been implicated in the bone deformity hereditary multiple exostoses (HME), and it is now clear that HME is associated with mutations in the HS biosynthetic genes EXT1 and EXT2. Interestingly, HME is also associated with an increased risk of chondro‐ and osteo‐sarcomas. Methods and results Preliminary analysis of GAG samples purified from fibroblasts of both HME and isolated non‐HME exostoses patients reveal a dramatic shift in the ratio of CS : HS, with the HME and isolated cases having a much higher proportion of CS relative to normal controls. This is true in the case of both shed and cell surface material but is far more extreme in the latter, with the HS reducing from approximately 45% in the controls to less than 10% in HME patients. Initial analysis also reveals shortened chain length within these samples; indeed they often have two populations of chains present. Simple analysis of the total disaccharide composition of these samples demonstrates no significant differences against controls. However, detailed analysis of the subpopulations of chains (as determined by chain length) within these samples as well as cartilaginous samples from exostoses patients may provide further insight into the changes that occur within the biosynthetic pathway following disrupted EXT function. We are also carrying out immunocytochemistry with a variety of HS‐specific antibodies with the aim to further investigate normal HS structure and localization. This is being carried out on human primary chondrocytes isolated from normal patients and also adult mesenchymal stem cells as they undergo differentiation into chondrocytes. HS has been identified in both these cell types, and it is hoped that the manipulation of these cells through RNAi of different enzymes of the HS biosynthetic pathway will provide a suitable model for studying what changes may occur in cellular HS structures over the initial differentiation process in the growth plate. Discussion Together, these investigations should provide a good model to allow us to determine the role of HS in chondrocyte differentiation and maturation in both normal and diseased states. 相似文献
5.
Image-directed percutaneous biopsies with a biopsy gun 总被引:3,自引:0,他引:3
Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method. 相似文献
6.
7.
目的观察去甲硫氨酸全肠外营养对大鼠血清氨基酸谱等的影响.方法 Wistar大鼠24只,随机分为含甲硫氨酸(+MetTPN,n=12)和去甲硫氨酸全肠外营养2组(-MetTPN,n=12),分别给予相应的TPN支持.治疗7d后,每组随机抽取6只大鼠处死,检测血清FAA(HPLC法)、肝肾功能和全血常规,同时作心、肺、肝、肾组织病理学检查.两组其余大鼠继续原TPN治疗,观察生存期.结果 -MetTPN组大鼠血清游离Met、Cys明显降低,Asp、Glu、Ser等显著增高;大鼠体重下降;血清总蛋白和白蛋白水平下降;血常规和肾功能未见明显异常;组织学检查见肝细胞轻度肿胀,细胞核仁增粗,心肺肾未见明显异常;平均生存18d.对照组上述检查未见异常,除一只大鼠因导管并发症于TPN第16d死亡,其余大鼠全部存活.结论 -MetTPN一周可致大鼠血清游离Met、Cys明显降低和Asp、Glu、Ser等显著增高,及轻度肝功能改变;随着-MetTPN时间延长,出现严重的代谢紊乱和器官功能障碍导致死亡. 相似文献
8.
Lorraine B. Hardingham RN MA 《Nursing philosophy》2004,5(2):127-134
Abstract This paper will examine the concepts of integrity and moral residue as they relate to nursing practice in the current health care environment. I will begin with my definition and conception of ethical practice, and, based on that, will go on to argue for the importance of recognizing that nurses often find themselves in the position of compromising their moral integrity in order to maintain their self‐survival in the hospital or health care environment. I will argue that moral integrity is necessary to a moral life, and is relational in nature. When integrity is threatened, the result is moral distress, moral residue, and in some cases, abandonment of the profession. The solution will require more than teaching bioethics to nursing students and nurses. It will require changes in the health care environment, organizational culture and the education of nurses, with an emphasis on building a moral community as an environment in which to practise ethically. 相似文献
9.