全文获取类型
收费全文 | 558篇 |
免费 | 73篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 4篇 |
妇产科学 | 16篇 |
基础医学 | 61篇 |
口腔科学 | 4篇 |
临床医学 | 103篇 |
内科学 | 115篇 |
皮肤病学 | 10篇 |
神经病学 | 43篇 |
特种医学 | 23篇 |
外科学 | 122篇 |
综合类 | 7篇 |
预防医学 | 32篇 |
眼科学 | 4篇 |
药学 | 50篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 13篇 |
2019年 | 7篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 38篇 |
2014年 | 65篇 |
2013年 | 62篇 |
2012年 | 18篇 |
2011年 | 22篇 |
2010年 | 36篇 |
2009年 | 50篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 13篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有636条查询结果,搜索用时 10 毫秒
61.
Regulation of starvation- and virus-induced autophagy by the
eIF2α kinase signaling pathway 下载免费PDF全文
62.
63.
Jeffrey R. Stout PhD Maren S. Fragala PhD Jay R. Hoffman PhD Edward H. Robinson PhD IV William P. Mccormack PhD Jeremy R. Townsend MS Adam R. Jatjner MS Nadia S. Emerson MS Leonardo P. Oliveira MD David H. Fukuda PhD 《Muscle & nerve》2015,51(1):132-133
Introduction: The aim of this study was to examine the relationship between serum C‐terminal agrin fragment (CAF) concentrations and neuromuscular fatigue in older adults. Methods: Twenty‐two healthy older men and women volunteered for this study. Resting fasted blood samples were collected and prepared for measurement of serum CAF concentration by a commercially available ELISA kit. The onset of neuromuscular fatigue was measured by monitoring electromyographic fatigue curves from the vastus lateralis muscle using the physical working capacity at fatigue threshold (PWCFT) test. Results: A significant inverse correlation for men was observed between CAF and PWCFT (r = ?0.602; P = 0.05), but not for women (r = 0.208; P = 0.54). After controlling for age and body mass index, significant correlations (r = ?0.69; P = 0.042) remained for men, but not for women (r = 0.12; P = 0.76). Conclusions: These data suggest that serum CAF concentrations were significantly related to the onset of neuromuscular fatigue independent of age and BMI in men only. Muscle Nerve 51 : 132–133, 2015 相似文献
64.
Xiaotong Chen Shyamal P. Choudhari Francisco J. Martinez-Becerra Jae Hyun Kim Nicholas E. Dickenson Ronald T. Toth IV Sangeeta B. Joshi Jamie C. Greenwood II John D. Clements William D. Picking C. Russell Middaugh Wendy L. Picking 《Infection and immunity》2015,83(1):292-299
Shigella spp. are causative agents of bacillary dysentery, a human illness with high global morbidity levels, particularly among elderly and infant populations. Shigella infects via the fecal-oral route, and its virulence is dependent upon a type III secretion system (T3SS). Two components of the exposed needle tip complex of the Shigella T3SS, invasion plasmid antigen D (IpaD) and IpaB, have been identified as broadly protective antigens in the mouse lethal pneumonia model. A recombinant fusion protein (DB fusion) was created by joining the coding sequences of IpaD and IpaB. The DB fusion is coexpressed with IpaB''s cognate chaperone, IpgC, for proper recombinant expression. The chaperone can then be removed by using the mild detergents octyl oligooxyethelene (OPOE) or N,N-dimethyldodecylamine N-oxide (LDAO). The DB fusion in OPOE or LDAO was used for biophysical characterization and subsequent construction of an empirical phase diagram (EPD). The EPD showed that the DB fusion in OPOE is most stable at neutral pH below 55°C. In contrast, the DB fusion in LDAO exhibited remarkable thermal plasticity, since this detergent prevents the loss of secondary and tertiary structures after thermal unfolding at 90°C, as well as preventing thermally induced aggregation. Moreover, the DB fusion in LDAO induced higher interleukin-17 secretion and provided a higher protective efficacy in a mouse challenge model than did the DB fusion in OPOE. These data indicate that LDAO might introduce plasticity to the protein, promoting thermal resilience and enhanced protective efficacy, which may be important in its use as a subunit vaccine. 相似文献
65.
César E. Rivas-Santiago Srijata Sarkar Pasquale Cantarella IV álvaro Osornio-Vargas Raúl Quintana-Belmares Qingyu Meng Thomas J. Kirn Pamela Ohman Strickland Judith C. Chow John G. Watson Martha Torres Stephan Schwander 《Infection and immunity》2015,83(6):2507-2517
Inhalation exposure to indoor air pollutants and cigarette smoke increases the risk of developing tuberculosis (TB). Whether exposure to ambient air pollution particulate matter (PM) alters protective human host immune responses against Mycobacterium tuberculosis has been little studied. Here, we examined the effect of PM from Iztapalapa, a municipality of Mexico City, with aerodynamic diameters below 2.5 μm (PM2.5) and 10 μm (PM10) on innate antimycobacterial immune responses in human alveolar type II epithelial cells of the A549 cell line. Exposure to PM2.5 or PM10 deregulated the ability of the A549 cells to express the antimicrobial peptides human β-defensin 2 (HBD-2) and HBD-3 upon infection with M. tuberculosis and increased intracellular M. tuberculosis growth (as measured by CFU count). The observed modulation of antibacterial responsiveness by PM exposure was associated with the induction of senescence in PM-exposed A549 cells and was unrelated to PM-mediated loss of cell viability. Thus, the induction of senescence and downregulation of HBD-2 and HBD-3 expression in respiratory PM-exposed epithelial cells leading to enhanced M. tuberculosis growth represent mechanisms by which exposure to air pollution PM may increase the risk of M. tuberculosis infection and the development of TB. 相似文献
66.
Development of intestinal organoids as tissue surrogates: Cell composition and the Epigenetic control of differentiation 下载免费PDF全文
67.
68.
Lim M Bower RS Wang Y Sims L Bower MR Camara-Quintana J Li G Cheshier S Harsh GR Steinberg GK Guccione S 《Neurosurgical review》2012,35(3):413-9; discussion 419
Vasospasm is a major contributor to morbidity and mortality in aneurysmal subarachnoid hemorrhage (SAH), with inflammation playing a key role in its pathophysiology. Myeloperoxidase (MPO), an inflammatory marker, was examined as a potential marker of vasospasm in patients with SAH. Daily serum samples from patients with aneurysmal SAH were assayed for MPO, and transcranial Doppler (TCDs) and neurological exams were assessed to determine vasospasm. Suspected vasospasm was confirmed by angiography. Peak MPO levels were then compared with timing of onset of vasospasm, based on clinical exams, TCDs and cerebral angiography. Patients with vasospasm had a mean MPO level of 115.5?ng/ml, compared to 59.4?ng/ml in those without vasospasm, 42.0?ng/ml in those with unruptured aneurysms, and 4.3?ng/ml in normal controls. In patients who experienced vasospasm, MPO was elevated above the threshold on the day of, or at any point prior to, vasospasm in 10 of 15 events (66.7%), and on the day of, or within 2?days prior to, vasospasm in 8 of 15 events (53.3%). Elevated serum MPO correlates with clinically evident vasospasm following aneurysmal SAH. The potential utility of MPO as a marker of vasospasm is discussed. 相似文献
69.
Brad J. Farrell Boris I. Prilutsky Robert S. Kistenberg John F. Dalton IV Mark Pitkin 《Clinical biomechanics (Bristol, Avon)》2014
Background
Despite the number of advantages of bone-anchored prostheses, their use in patients is limited due to the lack of complete skin–implant integration. The objective of the present study was to develop an animal model that would permit both detailed investigations of gait with a bone-anchored limb prosthesis and histological analysis of the skin–implant–bone interface after physiological loading of the implant during standing and walking.Methods
Full-body mechanics of walking in two cats were recorded and analyzed before and after implantation of a percutaneous porous titanium pylon into the right tibia and attachment of a prosthesis. The rehabilitation procedures included initial limb casting, progressively increasing loading on the implant, and standing and locomotor training. Detailed histological analysis of bone and skin ingrowth into implant was performed at the end of the study.Findings
The two animals adopted the bone-anchored prosthesis for standing and locomotion, although loads on the prosthetic limb during walking decreased by 22% and 62%, respectively, 4 months after implantation. The animals shifted body weight to the contralateral side and increased propulsion forces by the contralateral hindlimb. Histological analysis of the limb implants demonstrated bone and skin ingrowth.Interpretation
The developed animal model to study prosthetic gait and tissue integration with the implant demonstrated that porous titanium implants may permit bone and skin integration and prosthetic gait with a bone-anchored prosthesis. Future studies with this model will help optimize the implant and prosthesis properties. 相似文献70.
Christopher W. Jones Seema S. Sonnad James J. Augustine Charles L. Reese IV 《The American journal of emergency medicine》2014