首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   195638篇
  免费   8936篇
  国内免费   519篇
耳鼻咽喉   2889篇
儿科学   6150篇
妇产科学   4806篇
基础医学   26892篇
口腔科学   6509篇
临床医学   12848篇
内科学   46873篇
皮肤病学   6400篇
神经病学   15945篇
特种医学   4587篇
外国民族医学   30篇
外科学   24499篇
综合类   1055篇
一般理论   49篇
预防医学   18642篇
眼科学   3962篇
药学   13460篇
中国医学   841篇
肿瘤学   8656篇
  2023年   1139篇
  2022年   1679篇
  2021年   4412篇
  2020年   2308篇
  2019年   4421篇
  2018年   6357篇
  2017年   3932篇
  2016年   3860篇
  2015年   4183篇
  2014年   5512篇
  2013年   8013篇
  2012年   12779篇
  2011年   13431篇
  2010年   7141篇
  2009年   5839篇
  2008年   10973篇
  2007年   11580篇
  2006年   10954篇
  2005年   10883篇
  2004年   9786篇
  2003年   9277篇
  2002年   8780篇
  2001年   5968篇
  2000年   6504篇
  1999年   5170篇
  1998年   1301篇
  1997年   951篇
  1996年   860篇
  1995年   739篇
  1994年   596篇
  1993年   563篇
  1992年   2280篇
  1991年   2080篇
  1990年   1875篇
  1989年   1621篇
  1988年   1438篇
  1987年   1387篇
  1986年   1315篇
  1985年   1188篇
  1984年   882篇
  1983年   749篇
  1979年   787篇
  1975年   599篇
  1974年   676篇
  1973年   728篇
  1972年   626篇
  1971年   626篇
  1970年   606篇
  1969年   596篇
  1968年   538篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Maternal obesity may lead to epigenetic alterations in the offspring and might thereby contribute to disease later in life. We investigated whether a lifestyle intervention in pregnant women with obesity is associated with epigenetic variation in cord blood and body composition in the offspring. Genome-wide DNA methylation was analyzed in cord blood from 208 offspring from the Treatment of Obese Pregnant women (TOP)-study, which includes pregnant women with obesity randomized to lifestyle interventions comprised of physical activity with or without dietary advice versus control subjects (standard of care). DNA methylation was altered at 379 sites, annotated to 370 genes, in cord blood from offspring of mothers following a lifestyle intervention versus control subjects (false discovery rate [FDR] <5%) when using the Houseman reference-free method to correct for cell composition, and three of these sites were significant based on Bonferroni correction. These 370 genes are overrepresented in gene ontology terms, including response to fatty acids and adipose tissue development. Offspring of mothers included in a lifestyle intervention were born with more lean mass compared with control subjects. Methylation at 17 sites, annotated to, for example, DISC1, GBX2, HERC2, and HUWE1, partially mediates the effect of the lifestyle intervention on lean mass in the offspring (FDR <5%). Moreover, 22 methylation sites were associated with offspring BMI z scores during the first 3 years of life (P < 0.05). Overall, lifestyle interventions in pregnant women with obesity are associated with epigenetic changes in offspring, potentially influencing the offspring’s lean mass and early growth.  相似文献   
992.
Background of the studyThe goal of the study was to compare the incidence of complications, technical difficulty of intubation and physiologic pre-intubation status between the first intubation and reintubation performed on the same patient in an ICU.Materials and methodsThe study was approved by the ethics committee of Galicia (Santiago-Lugo, code No. 2015-012). Due to the observational, noninterventional, and noninvasive design of this study, the need for written consent was waived by the ethics committee of Galicia. Patients requiring tracheal intubation and reintubation in the ICU were included in this prospective observational study. Main endpoint was to compare the incidence of complications, physiologic pre-intubation status, and the rate of technical difficulty of intubation between the first intubation and reintubation performed on the same patient in an ICU.Results and discussion504 patients were intubated in our ICU during the study period, and 82 (16%) required reintubation. There was no difference between the first intubation and reintubation regarding number of total complication (35% vs 33%; P = .86), hypotension (24% vs 24%; P = 1), hypoxia (26% vs 26%; P = 1), esophageal intubation (1% vs 1%; P = 1), and bronchoaspiration (2% vs 1%; P = .86). Physiologic pre-intubation status and technical difficulty of intubation did not differ between the first intubation and reintubation.ConclusionsIn our ICU patients requiring tracheal reintubation, incidence of complications, physiologic pre-intubation status, and technical difficulty of intubation did not differ between the first intubation and reintubation.  相似文献   
993.
The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.  相似文献   
994.
IntroductionLiver transplantation is the standard treatment for end-stage liver disease. Brazil holds the third highest number of liver transplants performed per year, but center maldistribution results in high discrepancies in accessing this treatment. In 2012, an interstate partnership successfully implemented a new liver transplantation program in the middle west of Brazil. Here, we report the results of the first 500 liver transplants performed in this new program and discuss the impacts of a new transplant center in regional transplantation dynamics.MethodsWe reviewed data from the first 500 consecutive deceased donor liver transplants performed in the new program during an 8-year period. We analyzed data on patients’ clinical and demographic profiles, postoperative outcomes, and graft and recipient survival rates. Univariate survival analysis was conducted using log-rank tests to compare the groups.ResultsAlmost half (48%) of the procured organs and 40% of the recipients transplanted in our center were from outside our state. Recipient 30-day mortality was 9%. Overall recipient survival at 1 year and 5 years was 85% and 80%, respectively. Mortality was significantly associated with higher Model for End-Stage Liver Disease (P < .001) but not with the presence of hepatocellular carcinoma (P = .795).DiscussionThe new transplantation program treated patients from different regions of Brazil and became the reference center in liver transplantation for the middle west region. Despite the recent implementation, our outcomes are comparable to experienced centers around the world. This model can inspire the creation of new transplantation programs aiming to democratize access to liver transplantation nationwide.  相似文献   
995.
ContextThymoglobulin is used effectively as induction agent in kidney transplantation but the optimal dose is not well established.ObjectiveDemonstrate that low-dose thymoglobulin (3 mg/kg) has similar efficacy and safety compared to basiliximab induction in low-risk kidney transplantation under standard maintenance immunosuppressionDesign, Setting, ParticipantsProspective randomized study in kidney transplant patients (12/2016-05/2018). Inclusion criteria: Recipients > 18 years, first living donor transplant. Exclusion criteria: Second and multiorgan transplant, ABO incompatibility, positive cross-match, panel reactive antibodies (PRA) > 30%, positive donor-specific antibody, human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus positive, white blood cells < 2000 cells/mm3, platelets < 75,000 cells/mm3 and malignancy.InterventionGroup A: basiliximab (20 mg D0 and D4). Group B: thymoglobulin (3 mg/kg total). Maintenance immunosuppression: tacrolimus, mycophenolate mofetil, and steroids.Main Outcome MeasuresBiopsy-proven acute rejection (BPAR), delayed graft function, slow graft function, leukopenia, infections, adverse events, graft loss, estimated glomerular filtration rate, and death within 12 months.Results100 patients (basiliximab, n = 53) (thymoglobulin, n = 47) were included. Donor and recipient characteristics were similar except for longer dialysis (basiliximab), PRA class I (1.2% basiliximab, 4.5% thymoglobulin), HLA match (basiliximab 2.8, thymoglobulin 2.2), and cytomegalovirus status. BPAR rate was basiliximab 3.8% and thymoglobulin 6.4% (P = ns). Delayed graft function (basiliximab 3.8%; thymoglobulin 4.3%), slow graft function, and 12-month leukopenia (basiliximab 11.3%, thymoglobulin 21.3%) were similar between groups (P = ns). There was no difference in infections and adverse events between groups. Patient and graft survival were as follows: basiliximab 98.1% and 92.5%, thymoglobulin 100% and 93.6% (P = ns).ConclusionLow-dose thymoglobulin induction (3 mg/kg) can be used effectively and safely in low-risk kidney transplantation with good results during the first year post-transplant.  相似文献   
996.
The use of ultrasound as a clinical diagnostic tool and guide of bedside procedures has become an indispensable examination in the acute critically ill patient. The training of professionals in minimum skills of knowledge, management and indications of use of ultrasound required to be defined by the Scientific Societies. The Intensive Care Ultrasound Working Group of the Spanish Society of Anesthesiology and Resuscitation (SEDAR), of the Spanish Society of Internal Medicine (SEMI) and the Spanish Society of Emergency Medicine (SEMES) has developed this consensus document in which the recommended training program and the minimum competencies to be achieved with regard to the use of Ultrasound in Intensive Care, Anesthesia and Emergency medicine are defined.This document defines the training program and the skills to acquire in order to achieve the diploma in lung, abdominal and vascular ultrasound. This document can serve as a guide to define the skills to be acquired in the training programs of residents (MIRs) of specialists working in intensive care, anesthesia, and emergency medicine.  相似文献   
997.
Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation.  相似文献   
998.
999.
1000.
The aim of this study was the validation and transcultural adaptation of the Pain Scale for Plantar Fasciitis to Spanish, following the steps defined by “Guidelines for the process of cross-cultural adaptation of self-report measures.” A cross-sectional study was driven in 153 patients with unilateral plantar fasciitis diagnosis. Statistical analysis measured the internal consistency, the test-retest reliability, the construct validity with the Spanish version of Foot and Function Index, and a factorial analysis. The questionnaire Pain Scale for Plantar Fasciitis was also given to a group of 10 people who received a physiotherapy treatment based on manual therapy, therapeutic exercise, and health education, which aim was to determine the questionnaire's sensitivity to changes. The questionnaire showed high internal consistency and test-retest reliability (Cronbach's α = 0.99, intraclass correlation coefficient = 0.98 [0.97-0.98]), good convergent validity with a moderate correlation with the Foot and Function Index (rho = 0.677, p < .0001) and no floor or ceiling effects were detected. The factorial analysis revealed that the first 3 factors showed 42.47% of variance, finding only 1 latent feature. Statistically significant differences were found in those patients who received physiotherapy treatment after 1 month, revealing that the questionnaire was sensitive to changes in the symptoms of subjects with plantar fasciitis. The Spanish version of Pain Scale for Plantar Fasciitis has proved to be a valid, reliable, and change-sensitive tool for patients with plantar fasciitis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号