全文获取类型
收费全文 | 11594篇 |
免费 | 495篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 406篇 |
妇产科学 | 266篇 |
基础医学 | 1406篇 |
口腔科学 | 468篇 |
临床医学 | 1125篇 |
内科学 | 2577篇 |
皮肤病学 | 301篇 |
神经病学 | 1253篇 |
特种医学 | 377篇 |
外科学 | 1165篇 |
综合类 | 47篇 |
现状与发展 | 1篇 |
一般理论 | 3篇 |
预防医学 | 758篇 |
眼科学 | 159篇 |
药学 | 751篇 |
1篇 | |
中国医学 | 22篇 |
肿瘤学 | 996篇 |
出版年
2024年 | 47篇 |
2023年 | 92篇 |
2022年 | 156篇 |
2021年 | 302篇 |
2020年 | 192篇 |
2019年 | 270篇 |
2018年 | 308篇 |
2017年 | 236篇 |
2016年 | 262篇 |
2015年 | 282篇 |
2014年 | 416篇 |
2013年 | 495篇 |
2012年 | 723篇 |
2011年 | 754篇 |
2010年 | 443篇 |
2009年 | 385篇 |
2008年 | 657篇 |
2007年 | 690篇 |
2006年 | 668篇 |
2005年 | 635篇 |
2004年 | 547篇 |
2003年 | 490篇 |
2002年 | 438篇 |
2001年 | 248篇 |
2000年 | 252篇 |
1999年 | 270篇 |
1998年 | 104篇 |
1997年 | 84篇 |
1996年 | 80篇 |
1995年 | 75篇 |
1994年 | 48篇 |
1993年 | 47篇 |
1992年 | 147篇 |
1991年 | 143篇 |
1990年 | 126篇 |
1989年 | 113篇 |
1988年 | 101篇 |
1987年 | 98篇 |
1986年 | 88篇 |
1985年 | 72篇 |
1984年 | 65篇 |
1983年 | 47篇 |
1982年 | 24篇 |
1981年 | 36篇 |
1980年 | 26篇 |
1979年 | 51篇 |
1978年 | 25篇 |
1976年 | 28篇 |
1974年 | 23篇 |
1969年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The comorbid relationship between migraine and epilepsy: a systematic review and meta‐analysis
下载免费PDF全文
![点击此处可从《European journal of neurology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. R. Keezer P. R. Bauer M. D. Ferrari J. W. Sander 《European journal of neurology》2015,22(7):1038-1047
A number of studies have suggested a pathophysiologic link between migraine and epilepsy. Our aim was to examine the relative lifetime prevalence of migraine in people with epilepsy (PWE) as well that of epilepsy in migraineurs. We carried out a systematic review, searching five electronic databases, specified bibliographies and conference abstracts in order to identify population‐based studies that measured the lifetime co‐prevalence of migraine and epilepsy. Two reviewers independently screened all titles and abstracts, carried out a risk of bias assessment and extracted the data. Meta‐analyses were carried out using random effects models. Of the 3640 abstracts and titles screened, we identified 10 eligible studies encompassing a total of 1 548 967 subjects. Few of the studies used validated case ascertainment tools and there were inconsistent attempts to control for confounding. There was an overall 52% increase in the prevalence of migraine among PWE versus those without epilepsy [PR: 1.52 (95% CI: 1.29, 1.79)]. There was an overall 79% increase in the prevalence of epilepsy among migraineurs versus those without migraine [PR: 1.79 (95% CI: 1.43, 2.25)]. Subgroup analyses revealed that the method of ascertaining the epilepsy or migraine status of subjects was an important source of inter‐study heterogeneity. Additional high quality primary studies are required, ones that use validated and accurate methods of case ascertainment as well as control for potential confounders. 相似文献
92.
Jelle Koopsen Catharina E. van Ewijk Roisin Bavalia Akke Cornelissen Sylvia M. Bruisten Floor de Gee Alvin X. Han Maarten de Jong Menno D. de Jong Marcel Jonges Norin Khawaja Fleur M.H.P.A. Koene Mariken van der Lubben Iris Mikulic Sjoerd P.H. Rebers Colin A. Russell Janke Schinkel Anja J.M. Schreijer Judith A. den Uil Matthijs R.A. Welkers Tjalling Leenstra 《Emerging infectious diseases》2022,28(5):1012
We report a severe acute respiratory syndrome coronavirus 2 superspreading event in the Netherlands after distancing rules were lifted in nightclubs, despite requiring a negative test or vaccination. This occurrence illustrates the potential for rapid dissemination of variants in largely unvaccinated populations under such conditions. We detected subsequent community transmission of this strain. 相似文献
93.
Claudia Vales-Villamarín Jairo Lumpuy-Castillo Teresa Gavela-Prez Olaya de Dios Iris Prez-Nadador Leandro Soriano-Guilln Carmen Garcs 《Nutrients》2022,14(15)
Variations in the perilipin (PLIN) gene have been suggested to be associated with obesity and its related alterations, but a different nutritional status seems to contribute to differences in these associations. In our study, we examined the association of several polymorphisms at the PLIN locus with obesity and lipid profile in children, and then analyzed the mediation of plasma leptin levels on these associations. The single-nucleotide polymorphisms (SNPs) rs894160, rs1052700, and rs2304795 in PLIN1, and rs35568725 in PLIN2, were analyzed by RT-PCR in 1264 children aged 6–8 years. Our results showed a contrasting association of PLIN1 rs1052700 with apolipoprotein (Apo) A-I levels in boys and girls, with genotype TT carriers showing significantly higher Apo A-I levels in boys and significantly lower Apo A-I levels in girls. Significant associations of the SNP PLIN2 rs35568725 with high-density lipoprotein cholesterol (HDL-cholesterol), Apo A-I, and non-esterified fatty acids (NEFA) were observed in boys but not in girls. The associations of the SNPs studied with body mass index (BMI), NEFA, and Apo A-I in boys and girls were different depending on leptin concentration. In conclusion, we describe the mediation of plasma leptin levels in the association of SNPs in PLIN1 and PLIN2 with BMI, Apo A-I, and NEFA. Different leptin levels by sex may contribute to explain the sex-dependent association of the PLIN SNPs with these variables. 相似文献
94.
Ivabradine, the first representative of a new class of exclusive heart rate-reducing agents, selectively inhibits the I(f) current in the sinoatrial node. The direct electrophysiological consequence of this inhibition is a reduction in the slope of the diastolic depolarisation curve and a decrease in heart rate. Pharmacological inhibition of the I(f) current with ivabradine has been shown to preserve coronary vasodilatation upon exercise, i.e., myocardial perfusion, with no negative inotropic effects and maintenance of cardiac contractility. Ivabradine protects the myocardium during ischaemia, improves left ventricular function in congestive heart failure, and reduces remodelling subsequent to myocardial infarction. Pure heart rate reduction by specific and selective I(f) inhibition decreases oxygen demand, improves myocardial energetics and improves perfusion of the ischaemic myocardium. We can expect distinct clinical benefits from long-term heart rate reduction in patients with chronic ischaemic disease. 相似文献
95.
96.
Puglisi F Ridi R Cecchi F Bonelli A Ferrari R 《International journal of legal medicine》2004,118(4):235-239
The purpose of this study was to obtain comparative data concerning the relative contribution of segmental cervical vertebral motion to the cervical range of motion (ROM) in whiplash and healthy subjects in an effort to evaluate the usefulness of X-ray analysis in future forensic and research efforts. Each subjects neck ROM was measured with an optoelectronic system and also by X-ray measurements of the angular rotation in flexion and extension. The X-rays were examined to calculate the angular movement in the sagittal plane of each of the functional units C2–C3 to C6–C7. The chronic whiplash subjects showed reduced total neck range in all directions as compared to healthy subjects (p<0.001). There was a reduced total angular rotation from flexion to extension between these two groups (p<0.01), but no significant difference, however, between chronic whiplash subjects and controls in the percentage contribution of each of the functional units C2–C3 to C6–C7 to this rotation. This data will now allow a design of trials where healthy subjects are asked to simulate restricted neck ROM while undergoing optokinetic and X-ray evaluation of segmental vertebral motion. We will be able to determine if simulators produce a similar pattern to chronic whiplash and healthy, non-simulating subjects, and thus determine if, at least for forensic and research purposes, this technique is useful in validating reported restricted neck range. 相似文献
97.
Hinneburg I 《Medizinische Monatsschrift für Pharmazeuten》2011,34(5):154-158
Vernakalant is a new antiarrhythmic drug which is used for rapid conversion of atrial fibrillation. The drug is a relatively atrium-selective K' and Na+ channel blocker, prolonging the atrial refractory period. Clinical trials showed conversion rates of about 50% which is comparable to other antiarrhythmic drugs. Further trials will show if vernakalant is less pro-arrythmogenic than its competitors. 相似文献
98.
A. Marbini M. F. Bellanova A. Ferrari M. Lodesani F. Gemignani 《Acta neuropathologica》1997,94(2):103-108
We studied the immunohistochemical expression of laminin subunits α2, α1, β1 in muscle and skin biopsy samples from three
patients with congenital muscular dystrophy (CMD), and from ten control patients investigated for various neuromuscular disorders.
Merosin α2 chain was not detectable in the basement membrane of muscle fibers, or in the nerve endings, cutaneous nerves,
and corium in the skin of the CMD patients, whereas it was clearly expressed in the skin biopsy samples from control patients,
especially in the nerve endings of the arrector pili muscles. Laminin α1 chain was expressed in the corium, in the muscle
fiber membranes of arrector pili muscles and in cutaneous nerve fibers, perineurium and blood vessels in controls and in CMD
patients. Laminin β1 chain was faintly expressed in the corium, and a diffuse labeling was detected on arrector pili muscle
with enhanced expression at nerve endings, intracutaneous nerves and capillaries, with similar findings in all biopsy specimens.
For merosin-negative CMD patients, skin biopsy may provide a diagnostic alternative to muscle biopsy since merosin deficiency
can be demonstrated in the skin neural structures, and in particular in the nerve endings of the arrector pili smooth muscles.
Received: 29 October 1996 / Revised, accepted: 27 January 1997 相似文献
99.
Salvador Espino-y-Sosa Raigam Jafet Martinez-Portilla Johnatan Torres-Torres Juan Mario Solis-Paredes Guadalupe Estrada-Gutierrez Jose Antonio Hernandez-Pacheco Aurora Espejel-Nuez Paloma Mateu-Rogell Angeles Juarez-Reyes Francisco Eduardo Lopez-Ceh Jose Rafael Villafan-Bernal Lourdes Rojas-Zepeda Iris Paola Guzman-Guzman Liona C. Poon 《Viruses》2021,13(10)
Background: In healthy pregnancies, components of the Renin-Angiotensin system (RAS) are present in the placental villi and contribute to invasion, migration, and angiogenesis. At the same time, soluble fms-like tyrosine kinase 1 (sFlt-1) production is induced after binding of ANG-II to its receptor (AT-1R) in response to hypoxia. As RAS plays an essential role in the pathogenesis of COVID-19, we hypothesized that angiogenic marker (sFlt-1) and RAS components (ANG-II and ACE-2) may be related to adverse outcomes in pregnant women with COVID-19; Methods: Prospective cohort study. Primary outcome was severe pneumonia. Secondary outcomes were ICU admission, intubation, sepsis, and death. Spearman’s Rho test was used to analyze the correlation between sFlt-1 and ANG-II levels. The sFlt-1/ANG-II ratio was determined and the association with each adverse outcome was explored by logistic regression analysis and the prediction was assessed using receiver-operating-curve (ROC); Results: Among 80 pregnant women with COVID-19, the sFlt-1/ANG-II ratio was associated with an increased probability of severe pneumonia (odds ratio [OR]: 1.31; p = 0.003), ICU admission (OR: 1.05; p = 0.007); intubation (OR: 1.09; p = 0.008); sepsis (OR: 1.04; p = 0.008); and death (OR: 1.04; p = 0.018); Conclusion: sFlt-1/ANG-II ratio is a good predictor of adverse events such as pneumonia, ICU admission, intubation, sepsis, and death in pregnant women with COVID-19. 相似文献
100.
Iris M. C. van der Ploeg Hester S. A. Oldenburg Emiel J. T. Rutgers Marie-Jeanne T. F. D. Baas-Vrancken Peeters Bin B. R. Kroon Renato A. Valdés Olmos Omgo E. Nieweg 《Annals of surgical oncology》2010,17(4):1069-1075