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   6419篇
  免费   311篇
  国内免费   28篇
耳鼻咽喉   67篇
儿科学   117篇
妇产科学   124篇
基础医学   654篇
口腔科学   328篇
临床医学   320篇
内科学   1522篇
皮肤病学   305篇
神经病学   406篇
特种医学   308篇
外科学   1087篇
综合类   32篇
预防医学   156篇
眼科学   61篇
药学   499篇
中国医学   13篇
肿瘤学   759篇
  2023年   38篇
  2022年   75篇
  2021年   132篇
  2020年   81篇
  2019年   104篇
  2018年   131篇
  2017年   99篇
  2016年   99篇
  2015年   119篇
  2014年   149篇
  2013年   178篇
  2012年   245篇
  2011年   288篇
  2010年   154篇
  2009年   161篇
  2008年   303篇
  2007年   283篇
  2006年   262篇
  2005年   280篇
  2004年   255篇
  2003年   302篇
  2002年   287篇
  2001年   256篇
  2000年   258篇
  1999年   229篇
  1998年   83篇
  1997年   62篇
  1996年   63篇
  1995年   55篇
  1994年   51篇
  1993年   38篇
  1992年   167篇
  1991年   152篇
  1990年   152篇
  1989年   160篇
  1988年   135篇
  1987年   128篇
  1986年   91篇
  1985年   102篇
  1984年   65篇
  1983年   57篇
  1982年   30篇
  1981年   27篇
  1979年   63篇
  1978年   32篇
  1977年   23篇
  1975年   23篇
  1974年   42篇
  1968年   23篇
  1967年   22篇
排序方式: 共有6758条查询结果,搜索用时 139 毫秒
61.
A case of choledochal cyst (CC) antenatally diagnosed at 29 weeks' gestation is reported. Rapid enlargement of the cyst soon after delivery resulted in complete gastric outlet obstruction (GOO). The lesion was treated by external drainage as a temporary maneuver, with delayed cyst excision and hepaticoduodenostomy at the hepatic hilum performed at 81 days of age. Surgical treatment of CC in early infancy has been reported to be safe and effective. However, delayed primary excision would be an alternative procedure, especially in rare cases showing rapid enlargement resulting in GOO, since this choice has the potential advantage of allowing weight gain and improved nutritional status without risking interim complications due to the drainage procedure. Accepted: 24 March 1997  相似文献   
62.
Visual disturbances occur more frequently during preeclampsia than during pregnancy in general, but visual disturbances due to cranial nerve palsy are rare. We present the case of a 35-year-old preeclamptic woman with left third nerve palsy and left serous retinal detachment. The patient complained of visual disturbance and double vision soon after cesarean section. Left third nerve palsy and left serous retinal detachment were diagnosed by urgent ophthalmologic evaluation. Aneurysm and organic brain lesion were ruled out by diagnostic imaging. By 2 months postpartum, the visual disturbance had improved spontaneously.  相似文献   
63.
We conducted hemodilutional autotransfusion using a closed circuit combined with a cell washing reinfusing system (Cell Saver) for two surgical patients of Jehovah's Witness. One was a 12 yr-old boy for extirpation of the teratoma in the anterior mediastinum and another was a 44 yr-old woman for left total hip replacement. The patients and their relatives had consented to the use of blood substitutes, hemodilutional autotransfusion using a closed circuit and Cell Saver. We devised a closed circuit system for hemodilutional autotransfusion combined with Cell Saver, in which two pumps for blood transfusion were used; one was for drawing blood from the femoral or the internal jugular vein and the other for returning blood to the peripheral vein. Blood volume in a bag interposed in the closed circuit was easily controlled by adjusting the speed of each pump. Blood collected from the surgical field by Cell Saver was also led to the bag. Acid citrate dextrose solution was infused into the closed circuit from the site close to the blood drawing. Both of our surgical patients were safely managed without homologus blood transfusion, although there remained some problems concerning the use of anticoagulants.  相似文献   
64.
We examined the accuracy of electroneuronography (ENoG) and blink reflex as prognostic indicators in four patients with bilateral facial palsy. Electrophysiological investigation consisted of the recording of ENoG amplitude and R1 amplitude of blink reflex elicited by the peripheral nerve stimulation. Examinations were performed at the first visit, after 10 days, 2, 4 and 6 weeks. ENoG amplitude was less reliable for the neurological evaluation of bilateral facial palsy, because in three cases amplitude ratio of affected side to the other side was more than 100%. R1 amplitude of blink reflex recovered satisfactorily in two cases of good outcome. In other two cases of poor outcome, R1 amplitude was absent during the examination period. These findings suggest that analysis of blink reflex provides valuable information for evaluation of the prognosis of patients with bilateral facial palsy.  相似文献   
65.
Fulminant type 1 diabetes is characterized by a rapid progression of insulin deficiency triggered by viral infection. Here, we report a case of a 45‐year‐old Japanese woman with fulminant type 1 diabetes that developed 8 days after receiving messenger ribonucleic acid vaccine against severe acute respiratory syndrome coronavirus 2. She had been healthy and had no symptoms suggestive of viral infection before the vaccination. Laboratory tests showed exhaustion of insulin secretion and negative results for islet autoantibodies. Human leukocyte antigen genotype analysis showed the DRB1*04:05 and DQB1*04:01 alleles. This is the first case report of new‐onset fulminant type 1 diabetes after severe acute respiratory syndrome coronavirus 2 vaccination, and suggests that a severe acute respiratory syndrome coronavirus 2 vaccine might trigger the onset of fulminant type 1 diabetes in susceptible individuals. However, a causal relationship remains to be identified, and further studies are required to determine the incidence of such cases.  相似文献   
66.
The proximal isovelocity surface area (PISA) method for calculating volume flow through the regurgitant orifice has attracted significant attention. A number of in vitro studies and clinical studies in adults suggest that the method is accurate. However, when applying the method to children it must be noted that the absolute regurgitation volume is small, and the range of body sizes is wide. This study investigated the accuracy of the PISA method for quantitative assessment of the severity of mitral regurgitation in children. Twenty children aged 7 months to 12 years (average 4.7 years) with mitral regurgitation but without interventricular shunt or aortic stenosis were selected for this study. Underlying cardiac diseases included atrioventricular septal defects in nine, isolated mitral regurgitation in five, and association with other heart defects in six. The PISA radius (r) and the duration of regurgitation (T) were measured on color M-mode recordings, with the M line passing through the center of the PISA. Assuming that the PISA is a hemisphere, maximal regurgitant flow rate (MFR: ml/s) was calculated as MFR = 2π×~ r 2×~ V (r= maximal radius, V= aliasing velocity), and regurgitant stroke volume (RSVpisa) as RSVpisa = 2π×~ MSR ×~ V×~ T (MSR = mean square of the PISA radius during regurgitation). As a validating standard, total stroke volume (TSV) using two-dimensional echocardiography determined by the area–length volumetry method and forward stroke volume (FSV) by the pulsed Doppler method were measured, and regurgitant stroke volume (RSVD: RSVD= TSV − FSV) and regurgitant fraction (RF: RF = RSVD/TSV) were calculated. A linear correlation was found between MFR, RSVpisa, and RSVD (X) (MFR = 4.2X + 54.0, r= 0.84. RSVpisa = 1.0X + 9.8, r= 0.90), and both RSVpisa and MFR divided by body surface area (BSA: m2) revealed a significant correlation with regurgitant fraction (X) by nonlinear regression analysis (RSVpisa/BSA = 26.2 ×~ X/(1 − X) + 16.8, r= 0.85. MFR/BSA = 121.8 ×~ X/(1 − X) + 92.2, r= 0.79). It is concluded that maximal regurgitant flow rate, regurgitant stroke volume, and regurgitant fraction can be accurately predicted in children using the PISA method by Doppler echocardiography.  相似文献   
67.
The effect of radiotherapy during immunotherapy on immune-related adverse events (irAEs) is not fully understood. We herein report a 74-year-old woman diagnosed with lung adenocarcinoma with programmed death ligand 1 expression ≥50% and treated with pembrolizumab. She developed fatal immune thrombocytopenia associated with pembrolizumab immediately following radiotherapy. A flow cytometry analysis of peripheral blood detected an increased expression of programmed death-1 (PD-1) and Ki-67 in CD4 and CD8 T cells after radiotherapy, compared with pre-irradiation measurements. This case suggests that radiotherapy may evoke irAEs during treatment with anti-PD-1 antibodies, which physicians should consider when using radiotherapy in patients treated with these drugs.  相似文献   
68.
Clinical trials have not fully demonstrated the efficacy and safety of radiotherapy plus cetuximab for locally advanced squamous cell head and neck cancer (LA-SCCHN) in patients with cisplatin-ineligible renal dysfunction. Patients who received radiotherapy plus cetuximab for LA-SCCHN at Chiba University Hospital (Chiba, Japan) between July 2013 and October 2018 were retrospectively reviewed. Background characteristics and locoregional control and overall survival rates were compared between patients with and without renal dysfunction. Survival was examined using Kaplan-Meier analysis and an adjusted Cox proportional hazards model. Kaplan-Meier analysis demonstrated that overall survival was shorter in patients with creatinine clearance of <45 ml/min (P=0.041; log-rank test). However, there was no difference in the locoregional control rate (P=0.477; log-rank test). Adjusted Cox analysis revealed that the risk of death was increased by 2.52-fold (hazard ratio, 2.52; 95% confidence interval, 1.01-6.30; P=0.048) if creatinine clearance was <45 ml/min. Moderate to severe renal dysfunction did not affect the locoregional control rate in patients with LA-SCCHN treated with radiotherapy plus cetuximab but was an adverse prognostic factor.  相似文献   
69.
Neurokinin 2 receptor (NK2R), a G protein‐coupled receptor for neurokinin A (NKA), a tachykinin family member, regulates various physiological functions including pain response, relaxation of smooth muscle, dilation of blood vessels, and vascular permeability. However, the precise role and regulation of NK2R expression in cancer cells have not been fully elucidated. In this study, we found that high NK2R gene expression was correlated with the poor survival of colorectal cancer patients, and Interferon (IFN‐α/β) stimulation significantly enhanced NK2R gene expression level of colon cancer cells in a Janus kinas 1/2 (JAK 1/2)‐dependent manner. NKA stimulation augmented viability/proliferation and phosphorylation of Extracellular‐signal‐regulated kinase 1/2 (ERK1/2) levels of IFN‐α/β‐treated colon cancer cells and NK2R blockade by using a selective antagonist reduced the proliferation in vitro. Administration of an NK2R antagonist alone or combined with polyinosinic‐polycytidylic acid, a synthetic analog of double‐stranded RNA, to CT26‐bearing mice significantly suppressed tumorigenesis. NK2R‐overexpressing CT26 cells showed enhanced tumorigenesis and metastatic colonization in both lung and liver after the inoculation into mice. These findings indicate that IFN‐α/β‐mediated NK2R expression is related to the malignancy of colon cancer cells, suggesting that NK2R blockade may be a promising strategy for colon cancers.  相似文献   
70.
The present COVID-19 emergency has dramatically increased the demand for pharmaceutical containers, especially vials. End-of-life containers, however, cannot be easily recycled in the manufacturing of new articles. This paper presents some strategies for upcycling of pharmaceutical glass into various porous ceramics. Suspensions of a fine glass powder (70 vol%) are used as a starting material. Highly uniform cellular structures may be easily prepared by vigorous mechanical stirring of partially gelified suspensions with added surfactant, followed by drying and firing at 550–650 °C. Stabilization of the cellular structures at temperatures as low as the glass transition temperature (Tg) of the used glass is facilitated by thermal decomposition of the gel phase, instead of viscous flow sintering of glass. This finding enabled the preparation of glass membranes (∼78 vol% open porosity), by direct firing of hardened suspensions, avoiding any surfactant addition and mechanical stirring. The powders obtained by crushing of hardened suspensions, even in unfired state, may be used as a low-cost sorbent for dye removal.  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