全文获取类型
收费全文 | 14603篇 |
免费 | 1209篇 |
国内免费 | 369篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 245篇 |
妇产科学 | 110篇 |
基础医学 | 3316篇 |
口腔科学 | 345篇 |
临床医学 | 1213篇 |
内科学 | 2295篇 |
皮肤病学 | 231篇 |
神经病学 | 2016篇 |
特种医学 | 255篇 |
外国民族医学 | 2篇 |
外科学 | 1060篇 |
综合类 | 1307篇 |
现状与发展 | 4篇 |
预防医学 | 742篇 |
眼科学 | 277篇 |
药学 | 1580篇 |
3篇 | |
中国医学 | 657篇 |
肿瘤学 | 443篇 |
出版年
2024年 | 23篇 |
2023年 | 267篇 |
2022年 | 446篇 |
2021年 | 639篇 |
2020年 | 473篇 |
2019年 | 504篇 |
2018年 | 495篇 |
2017年 | 496篇 |
2016年 | 481篇 |
2015年 | 465篇 |
2014年 | 796篇 |
2013年 | 983篇 |
2012年 | 738篇 |
2011年 | 797篇 |
2010年 | 658篇 |
2009年 | 681篇 |
2008年 | 679篇 |
2007年 | 586篇 |
2006年 | 520篇 |
2005年 | 529篇 |
2004年 | 435篇 |
2003年 | 374篇 |
2002年 | 294篇 |
2001年 | 295篇 |
2000年 | 252篇 |
1999年 | 253篇 |
1998年 | 265篇 |
1997年 | 287篇 |
1996年 | 250篇 |
1995年 | 224篇 |
1994年 | 225篇 |
1993年 | 189篇 |
1992年 | 169篇 |
1991年 | 161篇 |
1990年 | 141篇 |
1989年 | 134篇 |
1988年 | 110篇 |
1987年 | 94篇 |
1986年 | 74篇 |
1985年 | 151篇 |
1984年 | 125篇 |
1983年 | 99篇 |
1982年 | 78篇 |
1981年 | 69篇 |
1980年 | 57篇 |
1979年 | 40篇 |
1978年 | 26篇 |
1977年 | 22篇 |
1976年 | 14篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Mohammad H. Ebrahimzadeh MD Mohammad T. Rajabi MD 《The Journal of foot and ankle surgery》2007,46(6):429-433
Long-term clinical and functional outcomes for patients undergoing foot and ankle amputations are not well documented. We attempted to document long-term outcomes for patients who required lower extremity amputations as a result of wounds suffered during wartime. For this study, 27 Iranian soldiers who had wounds requiring amputation of the foot and ankle were selected for follow-up. The participants' wartime medical records were reviewed, a clinical examination was performed, and each participant completed a questionnaire. Postamputation follow-up averaged 17.5 years. The most prevalent (66.6%) cause of injury was a land mine. The prevalences of different clinical symptoms reported by the amputees at the time of the last follow-up were as follows: 11 (40.7%) with phantom sensation, 6 (22.2%) with phantom pain, 12 (44.4%) with stump pain, 12 (44.4%) with back pain, 9 (33.3%) with contralateral knee pain, and 4 (14.8%) with ipsilateral knee pain; 20 (74%) reported treatment for psychological conditions. In regard to social conditions, 13 (48.1) were currently employed, or had been employed, for a number of years after the amputation; 26 (96%) had children, and all of the patients were married. The results of this observational study indicate that individuals have significant long-term pain and discomfort after war-related lower extremity amputation. Although all 27 (100%) of the amputees were able to maintain satisfactory family functioning, only 13 (48.1%) of the study participants were able to remain productively employed after undergoing amputation, and 20 (74%) reported long-term psychological problems in addition to their physical pain. 相似文献
72.
BACKGROUND: Suprasphincteric fistulae remain the most difficult to cure. OBJECTIVES: The purpose of this study was to evaluate the healing rate of suprasphincteric anal fistula treated by ano-cutaneous advancement flap repair, and the impact of this procedure on continence and quality of life. METHOD: Sixteen patients with complex, recurrent or chronic suprasphincteric fistulae associated with significant tissue damage (necrotizing fasciitis, keyhole deformity and anal stenosis) or who had failed previous surgical procedures were treated by ano-cutaneous flap closure. They were assessed pre and postoperatively by the treating surgeon for wound healing and fistula recurrence and later followed up by phone interview using the St Mark's Hospital incontinence score and the Perianal Disease Activity Index (PDAI) as indicators of treatment outcome. RESULTS: Fifteen patients had successful healing of their fistula with the cutaneous flap, with recurrence in only one. The most common short-term complications were minor graft site wound separation, which healed in all cases without intervention, and wound pain, which settled over time and was not associated with recurrence. Continence improved for almost 70% of the patients, with a significant reduction in St Mark's incontinence scores (t = 2.62, 15 d.f., P = 0.02). PDAI also decreased significantly (t = 7.55, 15 d.f., P < 0.001), demonstrating improvement in quality of life for most patients. CONCLUSION: Ano-cutaneous flap can achieve healing of complex and recurrent suprasphincteric anal fistula in patients who had previously failed at other forms of treatment thus improving their quality of life and continence. 相似文献
73.
74.
Noriyuki Kimura Toshihide Kumamoto Hidetsugu Ueyama Hideo Horinouchi Eisaku Ohama 《Neuropathology》2007,27(6):522-530
We examined the role of the 20S proteasome in pathologic changes, including abnormal aggregation of phosphorylated neurofilaments, of spinal motor nerve cells from aluminum‐treated rabbits. Immunohistochemistry for the 20S proteasome revealed that many lumbar spinal motor neurons without intracytoplasmic neurofilamentous inclusions or with small inclusions were more intensely stained in aluminum‐treated rabbits than in controls, whereas the immunoreactivity was greatly decreased in some enlarged neurons containing large neurofilamentous inclusions. Proteasome activity in whole spinal cord extracts was significantly increased in aluminum‐treated rabbits compared with controls. Furthermore, Western blot analysis indicated that the 20S proteasome degraded non‐phosphorylated high molecular weight neurofilament (neurofilament‐H) protein in vitro. These results suggest that aluminum does not inhibit 20S proteasome activity, and the 20S proteasome degrades neurofilament‐H protein. We propose that abnormal aggregation of phosphorylated neurofilaments is induced directly by aluminum, and is not induced by the proteasome inhibition in the aluminum‐treated rabbits. Proteasome activation might be involved in intracellular proteolysis, especially in the earlier stages of motor neuron degeneration in aluminum‐treated rabbits. 相似文献
75.
《Journal of labelled compounds & radiopharmaceuticals》2003,46(13):1241-1247
Tritium was introduced into the new orally active, selective phosphodiesterase type V (PDE V) inhibitor vardenafil (Levitra®), by reduction of a suitable amide precursor with freshly prepared lithium aluminum tritide. A specific activity of 52.7 Ci/mmol (1.95 TBq/mmol) was achieved. In order to overcome the usual technical difficulties during the preparation of complex tritides a new and easy labeling technique which has considerable potential for various tritia‐tion procedures, was developed. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
76.
Despite the fact that both H-2K and D molecules are up-regulated in the central nervous system (CNS) following Theiler's murine encephalomyelitis virus (TMEV) infection, resistance in this virus model of multiple sclerosis maps exclusively to D. To address this paradox, we examined the ability of the K and D molecules to present viral antigens to cytotoxic T lymphocytes (CTL). Whereas no virus-specific CTL were detected in the CNS of susceptible B10.Q and B10.S mice 7 days post-infection, D-restricted CTL were identified readily in the CNS of resistant B10 animals. There was no evidence of K-restricted CTL in the CNS of B10 mice at day 7 post-infection. The presence of both K- and D-restricted virus-specific CTL in the spleen of immunized B10 mice demonstrates that the exclusive use of D molecules by CTL in the CNS of mice 7 days post-infection is not due to the inability of the K molecules to present viral peptides to lymphocytes. We conclude that the prominent role of the D locus in determining resistance or susceptibility to TMEV-induced demyelination is determined by factors governing the regulation of the immune response, and not by the presence or absence of CTL precursors capable of recognizing viral peptides presented by the K and D antigen-presenting molecules, or by differences in the ability of the K and D molecules to present viral peptides. 相似文献
77.
合成了稀土(Ln)与2,2-联吡啶(L1)、1,10-菲罗啉(L2)的三元固态配合物。通过元素分析、IR谱、TGA谱和摩尔电导等对该系列配合物进行了表征,实测结果与通式LnL1L2Cl3·3H2O符合较好。抗菌试验表明,该系列配合物有较强的广谱抗菌作用。 相似文献
78.
In recent years, a growing interest in the study of peptide antigenicity in relation to the role of flanking sequences and protein topology in processing, presentation, and recognition has been observed. However, the information available on the antigenicity of recombinant fusion proteins and their effect on the selection of antigen receptor repertoires is limited. To analyze the role of molecular topology of T epitopes in a system relevant to human pathology, we have used the bacterially expressed Schistosoma japonicum glutathione S transferase (GST) to construct recombinant antigens containing HIV-1 derived T cell determinants, and human T cell clones specific for these determinants. We found that antigenicity of a given GST—peptide combination was not the same when T cells and antigen presenting cells from different individuals were tested. Our results show that differences in processing and presentation of chimeric proteins are not dictated by the use of diverse restriction elements. We also found that the context in which an antigenic peptide is delivered affects the recruited repertoire as defined according to T cell receptor Vβ usage and fine specificities of selected T cells. 相似文献
79.
Baljit Singh William P. Ireland Kanwaljit Minhas Onkar S. Atwal 《Anatomical record (Hoboken, N.J. : 2007)》1995,243(4):466-478
Background: Pulmonary intravascular macrophages (PIMs) of sheep have a globular surface coat that facilitates endocytosis of tracer particles and Escherichia coli lipopolysaccharide, and is disrupted by the heparin and Brefeldin A treatments. The present study investigated the in vivo dynamics of the coat globules following heparin-mediated removal, and the mechanism of globule organization on the plasma membrane of PIMs in vitro. Methods: Sheep were administered heparin at a dose of 50 IU/kg body weight IV, and euthanised at 30 min, 3, 6, 12, 48, and 120 hr (n = 2 for each treatment) after the treatment. Control sheep (n = 2) were injected with normal saline solution. The tissues were processed for an ultrastructural examination and acid phosphatase (ACPase) cytochemistry. Heparintreated lungs were subjected to morphometric analysis of the coat globules. Lung tissues from normal sheep (n = 2) were incubated with phosphatidylinositol-specific-phospholipase C (PIPLC; 2 IU/ml PBS) in vitro for 30 and 75 min. Results: Heparin study: The ultrastructural and morphometric data showed that the coat globules were removed at 30 min and reconstituted within 48 hr of the treatment. The PIMs showed priminent Golgi complexes associated with secretory vesicles, microtubules, and centriole between 3–12 hr of heparin treatment. Acid phosphatase cytochemistry also demonstrated secretory activity in the Golgi complexes of PIMs during the coat reconstitution. PIPLC study: The coat globules of PIMs were removed in a time-dependent mode by the PIPLC treatment without damage to other cell organelles. Conclusions: This study demonstrates a time-dependent reconstitution of the coat of PIMs in conjunction with secretory activity following heparinmediated removal, probably through sequenstration of the globules from blood. This ability is of functional significance as the coat mediates particle endocytosis by the PIMs. The results also suggest the presence of a glycosyl-phosphatidylinositol (GPI) anchor in tethering of globules on the plasma membrane of PIMs to offer a structural basis for their integrity in pulmonary vascular flow. © 1995 Wiley-Liss, Inc. 相似文献
80.
本文采用原子吸收的方法测定样品中糖胺多糖的含量。此法的灵敏度为0.102μg/ml,样品中铜检出值的变异系数为9%,平均回收率为103%,因此认为本方法的灵敏度、精密度和准确度都较高。此外,样品中存在的铜和葡萄糖对本实验均无干扰作用。 相似文献