全文获取类型
收费全文 | 5147篇 |
免费 | 94篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 304篇 |
妇产科学 | 59篇 |
基础医学 | 441篇 |
口腔科学 | 242篇 |
临床医学 | 377篇 |
内科学 | 966篇 |
皮肤病学 | 158篇 |
神经病学 | 396篇 |
特种医学 | 200篇 |
外科学 | 782篇 |
综合类 | 89篇 |
一般理论 | 1篇 |
预防医学 | 206篇 |
眼科学 | 219篇 |
药学 | 341篇 |
3篇 | |
中国医学 | 27篇 |
肿瘤学 | 400篇 |
出版年
2024年 | 37篇 |
2023年 | 44篇 |
2022年 | 74篇 |
2021年 | 178篇 |
2020年 | 89篇 |
2019年 | 139篇 |
2018年 | 149篇 |
2017年 | 134篇 |
2016年 | 145篇 |
2015年 | 181篇 |
2014年 | 254篇 |
2013年 | 306篇 |
2012年 | 469篇 |
2011年 | 506篇 |
2010年 | 263篇 |
2009年 | 216篇 |
2008年 | 306篇 |
2007年 | 310篇 |
2006年 | 251篇 |
2005年 | 279篇 |
2004年 | 239篇 |
2003年 | 182篇 |
2002年 | 169篇 |
2001年 | 22篇 |
2000年 | 14篇 |
1999年 | 36篇 |
1998年 | 32篇 |
1997年 | 22篇 |
1996年 | 18篇 |
1995年 | 13篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有5248条查询结果,搜索用时 15 毫秒
41.
Surana SP Doddamani S Swaminathan A Mehta MB Zeltser R Vatsia SK Makaryus AN 《Echocardiography (Mount Kisco, N.Y.)》2012,29(4):E102-E104
Approximately 1% of adults who undergo cardiac catheterization have coronary anomalies. Patients may present with chest pain, arrhythmias, presyncope, and sometimes sudden cardiac death. Multidetector computed tomography (MDCT) is an excellent tool for identifying coronary artery anomalies and defining their course and relationship to the great vessels and surrounding structures; its value is incremental to conventional angiography. We present a rare case of a coronary anomaly involving three separate ostia at the right sinus of Valsalva for the left and right coronary vessels. 相似文献
42.
Gagandeep Kaur Walia Simmi Saini Pradeep Vimal Khushboo Bhatia Arun Kumar Ranjana Singh Dorairaj Prabhakaran Vipin Gupta 《Diabetes & Metabolic Syndrome: Clinical Research & Reviews》2021,15(3):661-665
Background and aimsThe association of melanocortin receptor 4 (MC4R) gene with adiposity measures is widely studied in European populations. Only six studies have investigated the role of MC4R gene with adiposity measures among Indian populations. We have evaluated the role of MC4R (rs17782313) gene polymorphism in influencing adiposity measures in India among children and adults.Materials and methodsThe present population based cross sectional study was conducted among 303 individuals (208 children and 95 adults) of age group 10–30 years, belonging to Rajasthan. Somatometric measurements (standing height, weight, and waist and hip girths) and blood samples were taken after obtaining written informed consent. Genotyping of MC4R rs17782313 single nucleotide polymorphism was done using restriction fragment length polymorphism method for polymerase chain reaction ampli?ed fragments. We examined association between rs17782313 and different adiposity measures (height, weight, BMI, WHR, and waist and hip girths) using linear regression models.ResultsThe MC4R variant (rs17782313) predicted increased body weight (0.15 kg, S.E ± 0.076, P = 0.043) among children. In combined population, the rs17782313 variant was moderately associated with body weight (0.13 kg, S.E ± 0.070, P = 0.057). This variant was not found to be associated with any other adiposity measure.ConclusionFurther studies are needed to evaluate the association of MC4R variants through sequencing and functional genomics with different adiposity measures in Indian populations for understanding the genetic underpinnings of adiposity in India. 相似文献
43.
Lalit Kumar Bansal Stuti Gupta Arun Kumar Gupta Poras Chaudhary 《The Indian journal of tuberculosis》2021,68(2):272-278
Thyroid tuberculosis is a rare disease. Its incidence is low even in countries where prevalence of pulmonary tuberculosis is high (0.1–0.4%). In literature, there are only a few cases which were diagnosed as thyroid tuberculosis. It can be explained by a high resistance of the thyroid gland to infectious processes. However, the prevalence of tuberculosis has increased worldwide and thyroid involvement can be a primary manifestation of the disease. The incidence of extrapulmonary tuberculosis has been showing a progressive increase in the recent years(Barnes and Weatherstone, 1979). The most frequent clinical presentation is a solitary thyroid nodule that may present as a cystic nodule. It may also present as thyroid abscess with pain, fever and other non-specific signs and symptoms. ATT results in complete cure therefore it is important to differentiate it from other form of thyroiditis. Patients are usually euthyroid, but cases of hypothyroidism and hyperthyroidism are described. For accurate diagnosis of thyroid tuberculosis, clinical and radiological features are nonspecific and histological examination is required for confirmation of diagnosis. PCR may help in diagnosis. The authors encounter 3 cases of thyroid tuberculosis in last 5 year which are described in this article. The aim of this study is to review all the cases published in literature to describe clinical presentation, appropriate diagnostic method and possible treatment options of the disease. 相似文献
44.
Bhardwaj A Singh S Srivastava SK Honkanen RE Reed E Singh AP 《Molecular cancer therapeutics》2011,10(5):720-731
Earlier we identified PPP2CA, which encodes for the α-isoform of protein phosphatase 2A (PP2A) catalytic subunit, as one of the downregulated genes in androgen-independent prostate cancer. PP2A is a serine/threonine phosphatase and a potent tumor suppressor involved in broad cellular functions; however, its role in prostate cancer has not yet been determined. Here, we have investigated the effect of PP2A activity modulation on the androgen-independent growth of prostate cancer cells. Our data show that the PPP2CA expression and PP2A activity is downregulated in androgen-independent (C4-2) prostate cancer cells as compared with androgen-dependent (LNCaP) cells. Downregulation of PP2A activity by pharmacologic inhibition or short interfering RNA-mediated PPP2CA silencing sustains the growth of LNCaP cells under an androgen-deprived condition by relieving the androgen deprivation-induced cell-cycle arrest and preventing apoptosis. Immunoblot analyses reveal enhanced phosphorylation of Akt, extracellular signal-regulated kinase (ERK), BAD, increased expression of cyclins (A1/D1), and decreased expression of cyclin inhibitor (p27) on PP2A downregulation. Furthermore, our data show that androgen receptor (AR) signaling is partially maintained in PP2A-inhibited cells through increased AR expression and ligand-independent phosphorylation. Pharmacologic inhibition of Akt, ERK, and AR suggest a role of these signaling pathways in facilitating the androgen-independent growth of LNCaP cells. These observations are supported by the effect of ceramide, a PP2A activator, on androgen-independent C4-2 cells. Ceramide inhibited the growth of C4-2 cells on androgen deprivation, an effect that could be abrogated by PP2A downregulation. Altogether, our findings suggest that modulation of PP2A activity may represent an alternative therapeutic approach for the treatment of advanced androgen-independent prostate cancer. 相似文献
45.
Aaron Brody MD MPH Michael Twiner MD PhD Arun Kumar MD MPH Elizabeth Goldberg MD Candace McNaughton MD MPH Kimberly Souffront RN PhD Scott Millis PhD Phillip D. Levy MD MPH 《Journal of clinical hypertension (Greenwich, Conn.)》2017,19(3):265-269
Uncontrolled hypertension (HTN) is commonly encountered in emergency medicine practice, but the optimal approach to management has not been delineated. The objective of this study was to define emergency physician (EP) approaches to management of asymptomatic HTN in various clinical scenarios and assess adherence to the American College of Emergency Physician clinical policies, utilizing an online survey of EPs. A total of 1200 surveys were distributed by e‐mail with completion by 199 participants. The variables associated with a decision to prescribe oral antihypertensive medications were a history of HTN and referral from primary care. Acute blood pressure (BP) reduction using intravenous antihypertensive medications was also more likely with the latter and BP >180/120 mm Hg. Logistic regression revealed association of EP female sex, fewer years in practice, and a high‐volume practice setting with guideline‐concordant therapy. Wide variability exists in EP approaches to patients with asymptomatic HTN. Treatment decisions were impacted by patient history of chronic HTN, referral from primary care providers, and magnitude of BP elevation. 相似文献
46.
47.
48.
Megan Comerford Spencer Lourens Suthat Liangpunsakul Naga P. Chalasani Arun J. Sanyal Vijay H. Shah Patrick S. Kamath Puneet Puri Barry P. Katz Svetlana Radaeva David W. Crabb 《Alcoholism, clinical and experimental research》2017,41(12):2000-2006
The TREAT Consortium has carried out clinical studies on alcoholic hepatitis (AH) for over 4 years. We encountered problems with participant recruitment, retention, and eligibility for specific protocols. To improve our ability to carry out such trials, we reviewed recruitment screening logs, end of study logs, and surveyed study coordinators to learn the reasons for missing patients, why patients declined enrollment, and the number of patients eligible for treatment trials. Associations of the recruited subjects’ demographics with their adherence to follow‐up appointments were examined. Three hundred eight‐seven patients (AH and heavy drinking controls) were enrolled in the observational study, and 55 AH patients were recruited into treatment trials. About half of patients identified with AH could not be recruited; no specific reason could be determined for about two‐thirds of these. Among the patients who gave a reason for not participating, the most common reasons were feeling too sick to participate, desire to concentrate on abstinence, and lack of interest in research. Approximately a quarter of the AH patients met eligibility criteria for treatment trials for moderate or severe AH and we were able to recruit half to two‐thirds of those eligible. Approximately 35% of participants in the observational study returned for both 6‐ and 12‐month follow‐up visits. We did not identify biopsychosocial or demographic correlates of retention in the study. This analysis revealed that attempts at recruitment into trials for AH miss some subjects because of structural issues surrounding their hospital admission, and encounter a high rate of patient refusal to participate. Nonetheless, more than half of the patients who met the eligibility criteria for moderate or severe AH were entered into clinical trials. Retention rates for the observational study are relatively low. These findings need to be accounted for in clinical trial design and power analysis. 相似文献
49.
Francesca L. Beaudoin Arun Nagdev Roland C. Merchant Bruce M. Becker 《The American journal of emergency medicine》2010
Objectives
The primary objective of this study was to determine the feasibility of ultrasound-guided femoral nerve blocks in elderly patients with hip fractures in the emergency department (ED). The secondary objective was to examine the effectiveness of this technique as an adjunct for pain control in the ED.Methods
This prospective observational study enrolled a convenience sample of 13 patients with hip fractures. Ultrasound-guided femoral nerve block was performed on all participants. To determine feasibility, time to perform the procedure, number of attempts, and complications were measured. To determine effectiveness of pain control, numerical rating scores were assessed at baseline and at 15 minutes, 30 minutes, and hourly after the procedure for 4 hours. Summary statistics were calculated for feasibility measures. Wilcoxon matched-pairs signed-rank tests and Friedman analysis of variance test were used to compare differences in pain scores.Results
The median age of the participants was 82 years (range, 67-94 years); 9 were female. The median time to perform the procedure was 8 minutes (range, 7-11 minutes). All procedures required only one attempt; there were no complications. After the procedure, there were 44% and 67% relative decreases in pain scores at 15 minutes (P ≤ .002) and at 30 minutes (P ≤ .001), respectively. Pain scores were unchanged from 30 minutes to 4 hours after the procedure (P ≤ .77).Conclusions
Ultrasound-guided femoral nerve blocks are feasible to perform in the ED. Significant and sustained decreases in pain scores were achieved with this technique. 相似文献50.
Joel E. Lavine Jeffrey B. Schwimmer Jean P. Molleston Ann O. Scheimann Karen F. Murray Stephanie H. Abrams Philip Rosenthal Arun J. Sanyal Patricia R. Robuck Elizabeth M. Brunt Aynur Ünalp James Tonascia 《Contemporary clinical trials》2010,31(1):62-70
BackgroundNonalcoholic fatty liver disease (NAFLD) in children can lead to steatohepatitis, cirrhosis, and end-stage liver disease. The cause of NAFLD is unknown, but it is commonly associated with obesity, insulin resistance, and dyslipidemia.ObjectivesTONIC is conducted to test whether treatment with metformin, an insulin sensitizer, or vitamin E, a naturally available antioxidant, will lead to improvements in biochemical and histological features of nondiabetic children with biopsy-proven NAFLD.DesignTONIC is a randomized, multicenter, double-masked, placebo-controlled trial of 96 weeks of treatment with metformin or vitamin E. The primary outcome measure chosen for the trial is improvement in serum alanine aminotransferase (ALT) levels with treatment as compared to placebo. An improvement in ALT is defined as reduction in serum ALT levels to below 50% of the baseline values or into the normal range (40 U/L or less) during the last 48 weeks of treatment. Histological improvement is defined by changes in liver histology between a baseline and end-of-treatment liver biopsy in regards to (1) steatohepatitis, (2) NAFLD Activity Score, consisting of scores for steatosis, lobular inflammation, and hepatocellular injury (ballooning), and (3) fibrosis score.MethodsBetween September 2005 and September 2007, 173 children were enrolled into TONIC at 10 clinical centers in the United States. Participants were randomized to receive either metformin (500 mg b.i.d.), vitamin E (400 IU b.i.d.), or placebo for 96 weeks. This protocol was approved by all participating center Institutional Review Boards (IRBs) and an independent Data and Safety Monitoring Board (DSMB). (ClinicalTrials.gov number, NCT00063635.) 相似文献