全文获取类型
收费全文 | 161734篇 |
免费 | 10285篇 |
国内免费 | 1263篇 |
专业分类
耳鼻咽喉 | 2260篇 |
儿科学 | 3034篇 |
妇产科学 | 3747篇 |
基础医学 | 24078篇 |
口腔科学 | 3344篇 |
临床医学 | 15249篇 |
内科学 | 30854篇 |
皮肤病学 | 4356篇 |
神经病学 | 12068篇 |
特种医学 | 8092篇 |
外科学 | 21898篇 |
综合类 | 2196篇 |
现状与发展 | 6篇 |
一般理论 | 81篇 |
预防医学 | 9725篇 |
眼科学 | 4327篇 |
药学 | 13669篇 |
中国医学 | 1606篇 |
肿瘤学 | 12692篇 |
出版年
2023年 | 991篇 |
2022年 | 2752篇 |
2021年 | 4846篇 |
2020年 | 2478篇 |
2019年 | 3587篇 |
2018年 | 4413篇 |
2017年 | 3237篇 |
2016年 | 4196篇 |
2015年 | 5643篇 |
2014年 | 6914篇 |
2013年 | 8388篇 |
2012年 | 12680篇 |
2011年 | 12314篇 |
2010年 | 7269篇 |
2009年 | 6081篇 |
2008年 | 9278篇 |
2007年 | 9145篇 |
2006年 | 8400篇 |
2005年 | 7997篇 |
2004年 | 7132篇 |
2003年 | 6195篇 |
2002年 | 5386篇 |
2001年 | 4382篇 |
2000年 | 4028篇 |
1999年 | 3265篇 |
1998年 | 1310篇 |
1997年 | 991篇 |
1996年 | 951篇 |
1995年 | 863篇 |
1994年 | 753篇 |
1993年 | 642篇 |
1992年 | 1572篇 |
1991年 | 1571篇 |
1990年 | 1355篇 |
1989年 | 1237篇 |
1988年 | 1155篇 |
1987年 | 1030篇 |
1986年 | 1011篇 |
1985年 | 882篇 |
1984年 | 644篇 |
1983年 | 563篇 |
1982年 | 400篇 |
1981年 | 377篇 |
1980年 | 338篇 |
1979年 | 519篇 |
1978年 | 406篇 |
1977年 | 388篇 |
1976年 | 342篇 |
1974年 | 358篇 |
1973年 | 327篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
Previously, we prepared two different monoclonal antibodies (mAbs) against human 4-1BB (CD137): an agonistic mAb BBK-1 and an antagonistic mAb BBK-2. In this paper, we describe the molecular cloning of these two mAbs and present comparisons of their amino acid sequences. cDNAs encoding the heavy (H) and light (L) chains of the two mAbs were cloned by screening of cDNA libraries constructed from hybridomas secreting these mAbs. Comparisons of amino acid sequences of the two mAbs showed that, while the constant regions of the H and L chains were identical between the two mAbs, the variable region showed 45% identity in H chains and 48% identity in L chains. This suggests that these two mAbs recognize different epitopes of 4-1BB and may have different effects on the activity of 4-1BB. 相似文献
73.
Changes in outcome with sphincter preserving surgery for rectal cancer in Korea, 1991-2000. 总被引:3,自引:0,他引:3
S-B Lim S C Heo M R Lee S-B Kang Y J Park K J Park H S Choi S-Y Jeong J-G Park 《European journal of surgical oncology》2005,31(3):242-249
AIM: To report the clinical and oncological data of patients operated on for rectal cancers 3-5 cm from the AV over a 10 year period, including the Sphincter preservation (SP) rate. METHODS: We reviewed medical records of 304 patients with rectal cancers 3-5 cm from the AV who underwent surgical resection from January 1991 through December 2000. The 10 years were divided into three periods based on the introduction of new surgical techniques, specifically, ultralow anterior resection (ULAR) with double stapling in March 1994 and ULAR with coloanal anastomosis in April 1997. The rates of SP, complications and patient survival during these periods were compared. RESULTS: The SP rate increased significantly over the 10 years, from 16.4% in period I (January 1991-February 1994), to 53.0% in period II (March 1994-March 1997), to 86.5% in period III (April 1997-December 2000) (p<0.001). Over time, the age of the patients increased (p=0.004), the length of the distal resection margin became shorter (p=0.005), and the rate of lymph node metastasis increased (p=0.016). The factors significantly influencing SP were the period (p<0.001) and the distance from the AV (p<0.001). Over time, morbidity did not increase, and overall and disease free survival rates did not decrease. In contrast, the overall survival of N2 cases significantly increased over time (p=0.0492). CONCLUSION: Over 10 years, the SP rate in rectal cancers 3-5 cm from the AV was significantly increased by the introduction of the double stapling and coloanal anastomosis techniques. These surgical methods, however, had no effect on morbidity, disease free survival and overall survival rates. 相似文献
74.
B Lu J M Lee R Elliott C F Dreyfus J E Adler I B Black 《Brain research. Molecular brain research》1991,11(3-4):359-362
Nerve growth factor (NGF) gene expression in central nervous system (CNS) glia appears to be associated with active glial growth. To study the underlying molecular mechanisms, we examined the effects of a number of growth-related factors on NGF mRNA expression in glial cultures. Our results suggest that glial membrane interaction, as a consequence of growth, actively inhibits NGF gene expression in CNS glia. 相似文献
75.
Critical size defect in the canine mandible. 总被引:3,自引:0,他引:3
Jin-Young Huh Byung-Ho Choi Byung-Young Kim Seoung-Ho Lee Shi-Jiang Zhu Jae-Hyung Jung 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,100(3):296-301
OBJECTIVE: The purpose of this study was to determine the minimum size defect in a canine mandible that would not spontaneously heal during the dog's natural life (the critical size defect). STUDY DESIGN: Sixteen adult female mongrel dogs underwent continuity resection on both sides of the mandible to create bilateral defects. In 8 dogs, mandibular defects ranging from 5 to 20 mm were created with periosteal resection. In the other 8 dogs, mandibular defects ranging from 30 to 60 mm were created preserving the periosteum. The dogs were then killed at 6 months and the defects examined using radiographs and histologic analysis. RESULTS: When the periosteum was removed, mandibular defects greater than 15 mm failed to heal across the entire defect. However, when the periosteum was preserved, mandibular defects needed to be greater than 50 mm in order to fail to heal. CONCLUSION: The critical size defect in a canine mandible model is 15 mm when the periosteum is removed and 50 mm when the periosteum is preserved. 相似文献
76.
OBJECTIVE: This article 1) provides an overview of formal Health Sciences Teaching Scholars Programs as presented in medical education literature and 2) presents information about an innovative multidiscipline Teaching Scholars Program. METHOD: Health Sciences Teaching Scholars Programs and similar programs were reviewed in the medical education literature to identify similar and dissimilar characteristics. The WVU Teaching Scholars Program highlighted in this article is presented with a discussion of goals, objectives, target audiences, course length, session frequency, program topics, learning methods, and assessments of the programs. A summary of the WVU Teaching Scholars Program and two Teaching Scholars Programs at McGill University and the University of Toronto were presented at the Association for American Medical Colleges (AAMC) annual meeting in 2006 for input from the general medical education audience. RESULTS: Comparisons of Health Sciences Teaching Scholars Programs reveal that successful programs are uniquely shaped by their educational environments. Scholars report that they value learning new teaching methods and improving their educational careers. CONCLUSION: Teaching Scholars Programs are valuable for the development of enhancing both teaching and scholarship in Health Sciences Programs and must adapt to the uniqueness of their respective educational environments and must continue to nurture scholars beyond graduation. 相似文献
77.
Controlled release of lidocaine hydrochloride from the surfactant-doped hybrid xerogels. 总被引:2,自引:0,他引:2
We investigate the controlled release of lidocaine hydrochloride from the doped silica-based xerogels. In the xerogel preparation, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), and propyltriethoxysilane (PTES) are used as precursors, and a nonionic surfactant Igepal CO 720 is used as a dopant. The experimental results suggest that the release of lidocaine hydrochloride can be easily controlled by partially substituting TEOS with the organosilanes, and/or by adding the dopant. Adding the organosilane precursors lowers the release of both the drug and the surfactant in the order of TEOS, MTES/TEOS, and PTES/TEOS xerogels. The release from the PTES/TEOS xerogels is much lower than that from the other xerogels. The release of lidocaine hydrochloride is obviously suppressed by the addition of Igepal CO 720, while the release of Igepal CO 720 is slightly promoted by the addition of the drug. The overall release process is found to be diffusion-controlled, and the release behaviors can be well explained by considering the effects of the textual properties of the xerogels and the interactions among the drug, the surfactant, and the xerogel matrices. 相似文献
78.
K J Meador J L Thompson D W Loring A M Murro D W King B B Gallagher G P Lee J R Smith H F Flanigin 《Neurology》1991,41(6):869-872
Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms. 相似文献
79.
Paclitaxel with Cisplatin as Salvage Treatment for Patients with Previously Treated Advanced Transitional Cell Carcinoma of the Urothelial Tract
下载免费PDF全文
![点击此处可从《Neoplasia (New York, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
80.
Robert N. Page Lee Dittrich Roy King Fouad Boulos David L. Page 《Journal of cutaneous pathology》2009,36(11):1206-1209
Originally described by Rosen in 1983, syringomatous nipple adenoma (SAN) is a tumor of disputed histogenesis, which can be problematic both diagnostically and therapeutically. 1 It is a benign primary tumor of breast epithelium with histology similar to that of the syringoma. In the current case, we describe a 40-year-old female with this lesion occurring within a supernumerary breast. This case represents, to our knowledge, the first such reported case, and represents a significant finding as its presence could lend some confusion as to whether or not this represents a benign primary process of breast or a potentially infiltrative tumor of the skin. 相似文献