全文获取类型
收费全文 | 2821篇 |
免费 | 166篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 171篇 |
妇产科学 | 59篇 |
基础医学 | 289篇 |
口腔科学 | 60篇 |
临床医学 | 173篇 |
内科学 | 600篇 |
皮肤病学 | 72篇 |
神经病学 | 131篇 |
特种医学 | 156篇 |
外科学 | 598篇 |
综合类 | 51篇 |
一般理论 | 2篇 |
预防医学 | 73篇 |
眼科学 | 137篇 |
药学 | 134篇 |
中国医学 | 4篇 |
肿瘤学 | 262篇 |
出版年
2024年 | 7篇 |
2023年 | 25篇 |
2022年 | 16篇 |
2021年 | 171篇 |
2020年 | 65篇 |
2019年 | 120篇 |
2018年 | 127篇 |
2017年 | 75篇 |
2016年 | 94篇 |
2015年 | 125篇 |
2014年 | 148篇 |
2013年 | 182篇 |
2012年 | 241篇 |
2011年 | 238篇 |
2010年 | 121篇 |
2009年 | 93篇 |
2008年 | 148篇 |
2007年 | 157篇 |
2006年 | 127篇 |
2005年 | 124篇 |
2004年 | 108篇 |
2003年 | 92篇 |
2002年 | 70篇 |
2001年 | 21篇 |
2000年 | 41篇 |
1999年 | 37篇 |
1998年 | 15篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1971年 | 7篇 |
1968年 | 4篇 |
排序方式: 共有2993条查询结果,搜索用时 31 毫秒
61.
Vikram Kumar Yeragani Arindam Barua Indu Sattiraju Nikhil Mallavarapu 《Cardiovascular Engineering》2003,3(4):141-146
In this study, we evaluated the effectiveness of the statistic, Weighted Coherence in relation to the average or mean coherence in a particular frequency band after cross-spectral analysis. In time domain, correlation coefficient explains the relationship between two variables of interest, and a similar statistic in frequency domain using cross-spectral analysis is referred to as coherence, which is equivalent to the squared correlation coefficient and ranges from zero to unity. In this study, we show that weighted coherence is much more sensitive to various challenges within the same subject and also may be a more sensitive indicator of group differences in different frequency bands. Our data on normal subjects and patients with panic disorder during supine and standing postures during normal breathing, and also at different breathing rates throw new light on the sensitivity of this previously described novel index to quantify coherence between two related time series such as beat-to-beat heart rate and QT interval. 相似文献
62.
Rao Sanjay Kikano Elias G. Smith Daniel A. Tirumani Sree Harsha Ramaiya Nikhil H. 《Emergency radiology》2021,28(4):771-779
Emergency Radiology - Unintended weight loss (UWL) is a common presenting symptom in the emergency department (ED) with several etiologies. Our study looks to evaluate the diagnostic utility of... 相似文献
63.
Amit Mishra Megha Maheshwari Deepak Chhangani Noriko Fujimori-Tonou Fumito Endo Ajay Prakash Joshi Nihar Ranjan Jana Koji Yamanaka 《Neurobiology of aging》2013
Protein aggregation and ordered fibrillar amyloid deposition inside and outside of the central nervous system cells is the common pathologic hallmark of most aging-related neurodegenerative disorders. Dominant mutations in the gene encoding superoxide dismutase 1 (SOD1) protein are linked to familial amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by progressive degeneration of motor neurons, leading to muscle paralysis and death. The major histochemical hallmark in the remaining motor neurons of ALS is the intracellular accumulation of ubiquitinated inclusions consisting of insoluble aberrant protein aggregates. However, the molecular pathomechanisms underlying the process have been elusive. Here for the first time, we report that E6-AP, a homologous to E6-AP C terminus-type E3 ubiquitin ligase depleted in ALS mouse models before neurodegeneration. E6-AP coimmunoprecipitates with the SOD1 protein and is predominantly mislocalized in mutant SOD1-containing inclusion bodies. Overexpression of E6-AP increases the ubiquitination and facilitates degradation of SOD1 proteins. Finally, we show that the overexpression of E6-AP suppresses the aggregation and cell death mediated by mutated SOD1 proteins and cellular protective effect is more prominent when E6-AP is overexpressed along with Hsp70. These data suggest that enhancing the activity of E6-AP ubiquitin ligase might be a viable therapeutic strategy to eliminate mutant SOD1-mediated toxicity in ALS. 相似文献
64.
65.
66.
Kyle R. Taylor Adam P. DeLuca A. Eliot Shearer Michael S. Hildebrand E. Ann Black‐Ziegelbein V. Nikhil Anand Christina M. Sloan Robert W. Eppsteiner Todd E. Scheetz Patrick L. M. Huygen Richard J. H. Smith Terry A. Braun Thomas L. Casavant 《Human mutation》2013,34(4):539-545
Autosomal dominant nonsyndromic hearing loss (ADNSHL) is a common and often progressive sensory deficit. ADNSHL displays a high degree of genetic heterogeneity and varying rates of progression. Accurate, comprehensive, and cost‐effective genetic testing facilitates genetic counseling and provides valuable prognostic information to affected individuals. In this article, we describe the algorithm underlying AudioGene, a software system employing machine‐learning techniques that utilizes phenotypic information derived from audiograms to predict the genetic cause of hearing loss in persons segregating ADNSHL. Our data show that AudioGene has an accuracy of 68% in predicting the causative gene within its top three predictions, as compared with 44% for a majority classifier. We also show that AudioGene remains effective for audiograms with high levels of clinical measurement noise. We identify audiometric outliers for each genetic locus and hypothesize that outliers may reflect modifying genetic effects. As personalized genomic medicine becomes more common, AudioGene will be increasingly useful as a phenotypic filter to assess pathogenicity of variants identified by massively parallel sequencing. 相似文献
67.
68.
Effect of highly purified capsaicin on articular cartilage and rotator cuff tendon healing: An in vivo rabbit study 下载免费PDF全文
Nicole A. Friel Allison G. McNickle Michael J. DeFranco FanChia Wang Elizabeth F. Shewman Nikhil N. Verma Brian J. Cole Bernard R. Bach Jr. Susan Chubinskaya Susan M. Kramer Vincent M. Wang 《Journal of orthopaedic research》2015,33(12):1854-1860
Highly purified capsaicin has emerged as a promising injectable compound capable of providing sustained pain relief following a single localized treatment during orthopedic surgical procedures. To further assess its reliability for clinical use, the potential effect of highly purified capsaicin on articular cartilage metabolism as well as tendon structure and function warrants clarification. In the current study, rabbits received unilateral supraspinatus transection and repair with a single 1 ml injection of capsaicin (R + C), PEG‐only placebo (R + P), or saline (R + S) into the glenohumeral joint (GHJ). An additional group received 1 ml capsaicin onto an intact rotator cuff (I + C). At 18 weeks post‐op, cartilage proteoglycan (PG) synthesis and content as well as cell viability were similar (p > 0.05) across treatment groups. Biomechanical testing revealed no differences (p > 0.05) among tendon repair treatment groups. Similarly, histologic features of both cartilage and repaired tendons showed minimal differences across groups. Hence, in this rabbit model, a single injection of highly purified capsaicin into the GHJ does not induce a deleterious response with regard to cartilage matrix metabolism and cell viability, or rotator cuff healing. These data provide further evidence supporting the use of injectable, highly purified capsaicin as a safe alternative for management of postoperative pain following GHJ surgery. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1854–1860, 2015. 相似文献
69.
Combination of proteasome inhibitors bortezomib and NPI-0052 trigger in vivo synergistic cytotoxicity in multiple myeloma 总被引:1,自引:0,他引:1 下载免费PDF全文
Chauhan D Singh A Brahmandam M Podar K Hideshima T Richardson P Munshi N Palladino MA Anderson KC 《Blood》2008,111(3):1654-1664
Our recent study demonstrated that a novel proteasome inhibitor NPI-0052 triggers apoptosis in multiple myeloma (MM) cells, and importantly, that is distinct from bortezomib (Velcade) in its chemical structure, effects on proteasome activities, and mechanisms of action. Here, we demonstrate that combining NPI-0052 and bortezomb induces synergistic anti-MM activity both in vitro using MM cell lines or patient CD138(+) MM cells and in vivo in a human plasmacytoma xenograft mouse model. NPI-0052 plus bortezomib-induced synergistic apoptosis is associated with: (1) activation of caspase-8, caspase-9, caspase-3, and PARP; (2) induction of endoplasmic reticulum (ER) stress response and JNK; (3) inhibition of migration of MM cells and angiogenesis; (4) suppression of chymotrypsin-like (CT-L), caspase-like (C-L), and trypsin-like (T-L) proteolytic activities; and (5) blockade of NF-kappaB signaling. Studies in a xenograft model show that low dose combination of NPI-0052 and bortezomib is well tolerated and triggers synergistic inhibition of tumor growth and CT-L, C-L, and T-L proteasome activities in tumor cells. Immununostaining of MM tumors from NPI-0052 plus bortezomib-treated mice showed growth inhibition, apoptosis, and a decrease in associated angiogenesis. Taken together, our study provides the preclinical rationale for clinical protocols evaluating bortezomib together with NPI-0052 to improve patient outcome in MM. 相似文献
70.