全文获取类型
收费全文 | 2348篇 |
免费 | 179篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 90篇 |
妇产科学 | 28篇 |
基础医学 | 229篇 |
口腔科学 | 50篇 |
临床医学 | 226篇 |
内科学 | 505篇 |
皮肤病学 | 23篇 |
神经病学 | 65篇 |
特种医学 | 269篇 |
外科学 | 424篇 |
综合类 | 75篇 |
一般理论 | 1篇 |
预防医学 | 180篇 |
眼科学 | 49篇 |
药学 | 169篇 |
中国医学 | 9篇 |
肿瘤学 | 126篇 |
出版年
2021年 | 19篇 |
2020年 | 19篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 24篇 |
2016年 | 24篇 |
2015年 | 38篇 |
2014年 | 63篇 |
2013年 | 95篇 |
2012年 | 80篇 |
2011年 | 83篇 |
2010年 | 66篇 |
2009年 | 92篇 |
2008年 | 85篇 |
2007年 | 96篇 |
2006年 | 96篇 |
2005年 | 67篇 |
2004年 | 62篇 |
2003年 | 53篇 |
2002年 | 58篇 |
2001年 | 58篇 |
2000年 | 68篇 |
1999年 | 57篇 |
1998年 | 88篇 |
1997年 | 65篇 |
1996年 | 75篇 |
1995年 | 56篇 |
1994年 | 69篇 |
1993年 | 58篇 |
1992年 | 49篇 |
1991年 | 37篇 |
1990年 | 44篇 |
1989年 | 70篇 |
1988年 | 56篇 |
1987年 | 48篇 |
1986年 | 58篇 |
1985年 | 39篇 |
1984年 | 39篇 |
1983年 | 41篇 |
1982年 | 33篇 |
1981年 | 28篇 |
1980年 | 24篇 |
1979年 | 38篇 |
1978年 | 27篇 |
1977年 | 33篇 |
1976年 | 15篇 |
1975年 | 22篇 |
1974年 | 14篇 |
1973年 | 13篇 |
1972年 | 10篇 |
排序方式: 共有2537条查询结果,搜索用时 15 毫秒
101.
Ryan Cooney John R. Scott Madeline Mahowald Elizabeth Langen Garima Sharma David P. Kao Melinda B. Davis 《Clinical cardiology》2022,45(2):205
BackgroundDelays in diagnosis of peripartum cardiomyopathy (PPCM) are common and are associated with worse outcomes; however, few studies have addressed methods for improving early detection.HypothesisWe hypothesized that easily accessible data (heart rate [HR] and electrocardiograms [ECGs]) could identify women with more severe PPCM and at increased risk of adverse outcomes.MethodsClinical data, including HR and ECG, from patients diagnosed with PPCM between January 1998 and July 2016 at our institution were collected and analyzed. Linear and logistic regression were used to analyze the relationship between HR at diagnosis and the left ventricular ejection fraction (LVEF) at diagnosis. Outcomes included overall mortality, recovery status, and major adverse cardiac events.ResultsAmong 82 patients meeting inclusion criteria, the overall mean LVEF at diagnosis was 26 ± 11.1%. Sinus tachycardia (HR > 100) was present in a total of 50 patients (60.9%) at the time of diagnosis. In linear regression, HR significantly predicted lower LVEF (F = 30.00, p < .0001). With age‐adjusted logistic regression, elevated HR at diagnosis was associated with a fivefold higher risk of overall mortality when initial HR was >110 beats per minute (adjusted odds ratio 5.35, confidence interval 1.23–23.28), p = .025).ConclusionIn this study, sinus tachycardia in women with PPCM was associated with lower LVEF at the time of diagnosis. Tachycardia in the peripartum period should raise concern for cardiomyopathy and may be an early indicator of adverse prognosis. 相似文献
102.
103.
This is a retrospective chart review of perinatal outcomes of all primiparas over the age of 24 delivering at Maternity Center Associates, an out-of-hospital birth center, from January 1985 through May 1988 (N = 228). Chi-square analysis was used to determine whether mature primiparas, aged 35 to 43 (n = 27), had significantly more adverse outcomes than younger primiparas, aged 25 to 34 (n = 201). There was a significant difference between the groups in rate of transfer to hospital; however, there were no significant differences in rate of cesarean section, infant birth weight, apgar scores, and length of second stage labor. Implications for practice and future study are examined. 相似文献
104.
Nucleoside salvage pathways are vital to the parasitic protozoan Trypanosoma cruzi, and have become important targets in the development of new chemotherapeutic agents against this organism. We produced a mutant T. cruzi clone with a defect in the uptake of the adenosine analogue tubercidin which allowed us to hypothesize that there are at least two distinct nucleoside transport pathways in this parasite. The mutant shows a marked defect in the uptake of tubercidin and thymidine, whereas the uptake of adenosine and inosine are normal. Inhibition and metabolic studies suggest that the defect is related to transport and that there are two transport processes relatively specific for purines and pyrimidines, respectively, although tubercidin is transported via the latter. This is similar to the reported dual nucleoside transport pathways in Leishmania donovani and may be a common system in the Trypanosomatidae. These transport processes are markedly different from those which have been described for mammalian cells and may play an important role in the design of strategies for the chemotherapy of human infection with these pathogenic parasites. 相似文献
105.
106.
107.
目的探讨经关节入路微创钢板固定(MIPPO)技术治疗股骨远端C型骨折的临床疗效。方法2002年4月~2005年2月,应用MIPPO技术治疗股骨远端C型骨折14例,按AO/ASIF分类:C1型3例,C2型6例,C3型5例。先行关节内骨折切开复位、松质骨螺钉固定,再行髁上部分骨折间接复位、经关节内切口插入髁支撑钢板或LISS钢板桥接固定骨折。结果12例患者获得10~32个月(平均18.4个月)随访,骨折均获愈合,愈合时间10周~12个月,平均4.6个月。按Kolmert和Wulff的评价标准:优4例,良5例,可2例,差1例,优良率为75%。结论应用MIPPO技术治疗股骨远端C型骨折实现了微创操作,具有创伤小、软组织干扰少、骨折愈合快等优点,疗效满意。 相似文献
108.
蔡俊超 《中华移植杂志(电子版)》2010,(4)
随着器官移植体液免疫理论的发展与抗体检测技术的进步,抗体介导的排斥反应(AMR)已逐渐被认识和引起关注。其治疗难度大、逆转率较低,已成为导致移植物失功的重要原因。本文较为系统地介绍了AMR的免疫机制、诊断与防治进展,以及供者特异性抗体的检测技术和临床意义,从而提出供者特异性抗体是引起移植物排斥反应特别是慢性排斥反应的主要原因,移植受者需常规监测抗体以利及时干预和治疗。 相似文献
109.
Kyle L. Hoehn Adam B. Salmon Cordula Hohnen-Behrens Nigel Turner Andrew J. Hoy Ghassan J. Maghzal Roland Stocker Holly Van Remmen Edward W. Kraegen Greg J. Cooney Arlan R. Richardson David E. James 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(42):17787-17792
We know a great deal about the cellular response to starvation via AMPK, but less is known about the reaction to nutrient excess. Insulin resistance may be an appropriate response to nutrient excess, but the cellular sensors that link these parameters remain poorly defined. In the present study we provide evidence that mitochondrial superoxide production is a common feature of many different models of insulin resistance in adipocytes, myotubes, and mice. In particular, insulin resistance was rapidly reversible upon exposure to agents that act as mitochondrial uncouplers, ETC inhibitors, or mitochondrial superoxide dismutase (MnSOD) mimetics. Similar effects were observed with overexpression of mitochondrial MnSOD. Furthermore, acute induction of mitochondrial superoxide production using the complex III antagonist antimycin A caused rapid attenuation of insulin action independently of changes in the canonical PI3K/Akt pathway. These results were validated in vivo in that MnSOD transgenic mice were partially protected against HFD induced insulin resistance and MnSOD+/− mice were glucose intolerant on a standard chow diet. These data place mitochondrial superoxide at the nexus between intracellular metabolism and the control of insulin action potentially defining this as a metabolic sensor of energy excess. 相似文献
110.
C Badenas J To-Figueras JD Phillips CA Warby C Muñoz and C Herrero 《Clinical genetics》2009,75(4):346-353
Porphyria cutanea tarda (PCT) arises from decreased hepatic activity of uroporphyrinogen decarboxylase (UROD). Both genetic and environmental factors interplay in the precipitation of clinically overt PCT, but these factors may vary between different geographic areas. Decreased activity of UROD in erythrocytes was used to identify patients with UROD mutations among a group of 130 Spanish PCT patients. Nineteen patients (14.6%) were found to harbor a mutation in the UROD gene. Eight mutations were novel: M1I, 5del10, A22V, D79N, F84I, Q116X, T141I and Y182C. Five others were previously described: F46L, V134Q, R142Q, P150L and E218G. The new missense mutations and P150L were expressed in Escherichia coli. D79N and P150L resulted in proteins that were localized to inclusion bodies. The other mutations produced recombinant proteins that were purified and showed reduced activity (range: 2.3–73.2% of wild type). These single amino acid changes were predicted to produce complex structural alterations and/or reduced stability of the enzyme. Screening of relatives of the probands showed that 37.5% of mutation carriers demonstrated increased urinary porphyrins. This study emphasizes the role of UROD mutations as a strong risk factor for PCT even in areas where environmental factors (hepatitis C virus) have been shown to be highly associated with the disease. 相似文献