全文获取类型
收费全文 | 4454篇 |
免费 | 224篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 58篇 |
妇产科学 | 69篇 |
基础医学 | 545篇 |
口腔科学 | 184篇 |
临床医学 | 238篇 |
内科学 | 1347篇 |
皮肤病学 | 126篇 |
神经病学 | 276篇 |
特种医学 | 116篇 |
外科学 | 712篇 |
综合类 | 23篇 |
预防医学 | 122篇 |
眼科学 | 14篇 |
药学 | 301篇 |
中国医学 | 8篇 |
肿瘤学 | 536篇 |
出版年
2023年 | 52篇 |
2022年 | 106篇 |
2021年 | 150篇 |
2020年 | 67篇 |
2019年 | 85篇 |
2018年 | 107篇 |
2017年 | 83篇 |
2016年 | 103篇 |
2015年 | 94篇 |
2014年 | 117篇 |
2013年 | 178篇 |
2012年 | 307篇 |
2011年 | 325篇 |
2010年 | 177篇 |
2009年 | 146篇 |
2008年 | 261篇 |
2007年 | 255篇 |
2006年 | 264篇 |
2005年 | 278篇 |
2004年 | 229篇 |
2003年 | 197篇 |
2002年 | 257篇 |
2001年 | 65篇 |
2000年 | 62篇 |
1999年 | 73篇 |
1998年 | 58篇 |
1997年 | 52篇 |
1996年 | 42篇 |
1995年 | 38篇 |
1994年 | 24篇 |
1993年 | 21篇 |
1992年 | 48篇 |
1991年 | 48篇 |
1990年 | 45篇 |
1989年 | 42篇 |
1988年 | 40篇 |
1987年 | 32篇 |
1986年 | 31篇 |
1985年 | 26篇 |
1984年 | 12篇 |
1983年 | 18篇 |
1982年 | 7篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1974年 | 9篇 |
1973年 | 8篇 |
1972年 | 6篇 |
1970年 | 8篇 |
排序方式: 共有4714条查询结果,搜索用时 31 毫秒
1.
2.
Kentaro Yamasaki Takafumi Ishida Tatsuya Kishino Norio Niikawa 《American journal of medical genetics. Part A》2002,111(3):301-306
We report on a Thai family with dominantly inherited malformation syndrome with upper limb anomalies, short stature, quadricuspid aortic valve, and minor craniofacial anomalies. The affected individuals comprised a mildly affected mother, a moderately affected daughter, and a most severely affected son. The daughter and son had short stature. The craniofacial abnormalities comprised frontal bossing, hypoplastic nasal bones, depressed nasal bridge, and broad nasal alae. The upper limb defects varies among the patients, ranging from radial ray defects in the mother through radial and ulnar ray defects with unilateral humeral hypoplasia in the daughter to radial ray defects with severe oligodactyly and bilateral humeral hypoplasia in the son. All patients in this family had hypoplasia of the shoulder girdle and resembled what is observed in many families with Holt‐Oram syndrome. Moreover, the son showed quadricuspid aortic valve with mild aortic regurgitation. However, the present family did not show any mutation of the TBX5 gene, a disease‐causing gene of Holt‐Oram syndrome. The present family deserves further investigation on other genes that play a role in the development of the upper limbs, particularly of radial rays. © 2002 Wiley‐Liss, Inc. 相似文献
3.
4.
K Sugino Y Kure R Shiraishi H Iwasaki H Sato Y Kumamoto A Matsumoto 《Nihon Geka Gakkai zasshi》1990,91(8):923-930
Recently, mean span of life has been prolonged, and extensive operations are performed on aged patients. However, there are cases which have a difference between their chronological and actual ages. Bone mineral content (BMC) decreases with age and the decrease in BMC might suggest deterioration of immunological competence as observed in osteoporosis. Whether BMC can be an index for evaluation of geriatric patients' actual age from the aspect of immunological competence was investigated. Subjects were 54 cases aged more than 60. Twenty-one healthy young males and females were enrolled as the control group. Quantitative CT is used for assessment of BMC. The value obtained by dividing BMC by the standard BMC of the same age and sex, was defined as BMC index. BMC indices of normal BMC group were more than 0.8 and those of decreased BMC group were less than 0.8. Some immunological markers were investigated. Lymphocyte subset OKT3+ was reduced and juvenile lymphocytes expressed by OKT6+ and OKT3+-(OKT4+ + OKT8+) increased (corrected). Increased in juvenile lymphocyte and decrease in lymphocyte blast transformation and competence of generating interleukin 2 were observed in decreased BMC group. BMC is useful as preoperative evaluation for geriatric operative cases and patients of BMC index below 0.8 need to be paid attention to postoperative infection. 相似文献
5.
Escherichia coli tryptophan repressor binds multiple sites within the aroH and trp operators 总被引:5,自引:0,他引:5
DNase I footprinting and methylation protection studies have been used to analyze the binding of Escherichia coli Trp repressor to the trpR, aroH, and trp operators. The methylation protection assay shows that Trp repressor binds in two successive major grooves of the trpR operator, three successive major grooves of the aroH operator, and four successive major grooves of the trp operator. The simplest model that explains the difference in Trp repressor interaction at the three operators is that the aroH and trp operators are composed of multiple, helically stacked binding sites. When viewed in three dimensions, each site is positioned on a different face of the DNA, and together process up the surface of the DNA helix. Analysis of a deletion derivative of the trp operator supports this model. 相似文献
6.
Shigeru Onodera Koji Saito Takafumi Saito Hitoshi Togashi Sumio Kawata Katsuaki Ukai Haruhide Shinzawa 《Nihon Shokakibyo Gakkai zasshi》2007,104(2):213-218
It is well known that long-term infection with Clonorchis sinensis often causes bile duct cancer, usually. It occurs in the intrahepatic bile duct. We encountered a rare case of clonorchiasis complicated with duodenal papillary cancer. The patient was a woman from China. Although clonorchiasis is rarely found in Japan, the promotion of international exchange may increase the number of visitors from endemic areas. Thus we must pay sufficient attention to this disease. Also, we reported that the microplate ELISA technique was useful in the diagnosis of clonorchiasis with high accuracy in this case. 相似文献
7.
Monoclonal Antibody Specific for TIRC7 Induces Donor-specific Anergy and Prevents Rejection of Cardiac Allografts in Mice 总被引:1,自引:0,他引:1
Yusuke Kumamoto Antje Tomschegg Fatima Bennai-Sanfourche Anke Boerner Arthur Kaser Isabella Schmidt-Knosalla Thomas Heinemann Mirko Schlawinsky Richard S. Blumberg Hans-Dieter Volk Nalan Utku 《American journal of transplantation》2004,4(4):505-514
T cell immune response c-DNA (TIRC7) is up-regulated during the early stages of T-cell activation in response to alloantigens. In this study, we analyzed the effects of newly developed monoclonal antibodies (mAb) against TIRC7 in acute cardiac allograft rejection. Fully vascularized heterotopic allogeneic heart transplantation was performed in mice across a full-mismatch barrier (C57Bl/10 into CBA). Recipients received seven injections (day 0-7) of a novel anti-TIRC7 mAb or remained untreated. Graft survival, histology and ex vivo lymphocyte functions were tested. Targeting of TIRC7 with an anti-TIRC7 mAb diminishes lymphocyte infiltration into grafts resulting in delay of morphological graft damage and prolongation of allograft survival. The lymphocytes from anti-TIRC7 mAb-treated animals exhibit hypo-responsiveness without evidence of lymphocyte depletion against the donor allo-antigens. Proliferation and expression of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) were down-regulated while interleukin-4 (IL-4) and IL-10 expression were spared. Moreover, anti-TIRC7 mAb enhanced up-regulation of CTLA-4 expression but suppressed up-regulation of CD25 on stimulated lymphocytes in vitro and in vivo. Ligation of TIRC7 has important effects on the regulation of co-stimulatory signaling pathways associated with suppressing of T-cell activation. Targeting of TIRC7 may therefore provide a novel therapeutic approach for modulating T cell immune responses during organ transplantation. 相似文献
8.
Yukata Okita M.D. Shigehito Miki M.D. Yuichi Ueda M.D. Takafumi Tahata M.D. Tetsuro Sakai M.D. Katsuhiko Matsuyama M.D. Masahiko Matsumura M.D. 《Journal of cardiac surgery》1994,9(4):433-439
A 6-year-old boy was successfully operated on for double outlet ventricle, common atrioventricular canal with severe valvular regurgitation, right atrial Isomerism, L-loop ventricles, total anomalous pulmonary venous connection, and pulmonary stenosis with hypoplastic left pulmonary artery. The Interventricular rerouting from the left ventricle to the ascending aorta was performed with a spiral patch, the lnteratrlal switching was performed by a Mustard patch, the common atrioventricular orifice was partitioned and valve repair was performed, and an 18-mm valved conduit was inserted between the right ventricle and the pulmonary artery. Although the patient had a small residual ventricular septal defect and pulmonary stenosls, the patient Is alive and well. 相似文献
9.
10.
Hiroyuki Kumamoto Nobuhiro Takahashi Kiyoshi Ooya 《Journal of oral pathology & medicine》2004,33(6):360-367
BACKGROUND: To clarify the roles of rat sarcoma (Ras)/mitogen-activated protein kinase (MAPK) signaling pathway in oncogenesis and cytodifferentiation of odontogenic tumors, K-Ras gene status and expression of Ras, Raf1, MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)1, and ERK1/2 proteins were analyzed in ameloblastomas as well as in tooth germs. METHODS: Paraffin sections of 10 tooth germs and 46 benign and 6 malignant ameloblastomas were examined immunohistochemically for the expression of K-Ras, Raf1, MEK1, and ERK1/2. Frozen tissue samples of 22 benign ameloblastomas and 1 malignant (metastasizing) ameloblastoma were analyzed by direct DNA sequencing to detect K-Ras gene alteration. RESULTS: Immunohistochemical reactivity for K-Ras, Raf1, MEK1, and ERK1/2 was detected in both normal and neoplastic odontogenic epithelium, and these molecules were reactive chiefly with odontogenic epithelial cells neighboring the basement membrane. Plexiform ameloblastomas showed slightly stronger expression of these Ras/MAPK signaling molecules than follicular ameloblastomas. Keratinizing cells and granular cells showed decreased reactivity for the signaling molecules. Basal cell ameloblastomas showed slightly stronger reactivity for the signaling molecules than did the other subtypes. K-Ras immunoreactivity in malignant ameloblastomas was lower than that in dental lamina of tooth germs. Direct DNA sequencing showed a GGT to GCT point mutation at codon 12 of K-Ras gene in one ameloblastoma. Conclusion: Expression of K-Ras, Raf1, MEK1, and ERK1/2 in tooth germs and ameloblastomas suggests that Ras/MAPK signaling pathway functions to regulate cell proliferation and differentiation in both normal and neoplastic odontogenic epithelium. K-Ras gene status implied that K-Ras mutations might play a minor role in oncogenesis of odontogenic epithelium. 相似文献