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   1271篇
  免费   42篇
  国内免费   3篇
耳鼻咽喉   120篇
儿科学   12篇
妇产科学   18篇
基础医学   85篇
口腔科学   28篇
临床医学   68篇
内科学   260篇
皮肤病学   44篇
神经病学   65篇
特种医学   31篇
外科学   251篇
综合类   5篇
预防医学   33篇
眼科学   62篇
药学   102篇
中国医学   2篇
肿瘤学   130篇
  2023年   7篇
  2022年   10篇
  2021年   18篇
  2020年   10篇
  2019年   18篇
  2018年   21篇
  2017年   16篇
  2016年   22篇
  2015年   18篇
  2014年   27篇
  2013年   32篇
  2012年   38篇
  2011年   60篇
  2010年   39篇
  2009年   35篇
  2008年   54篇
  2007年   55篇
  2006年   41篇
  2005年   54篇
  2004年   55篇
  2003年   46篇
  2002年   62篇
  2001年   48篇
  2000年   48篇
  1999年   49篇
  1998年   13篇
  1996年   11篇
  1995年   12篇
  1992年   31篇
  1991年   12篇
  1990年   28篇
  1989年   22篇
  1988年   36篇
  1987年   41篇
  1986年   19篇
  1985年   22篇
  1984年   11篇
  1983年   9篇
  1982年   11篇
  1979年   22篇
  1978年   7篇
  1977年   12篇
  1976年   11篇
  1975年   8篇
  1974年   11篇
  1973年   11篇
  1972年   9篇
  1971年   9篇
  1969年   7篇
  1966年   7篇
排序方式: 共有1316条查询结果,搜索用时 15 毫秒
81.
A new method has been developed for automatic measurement of polyethylene linear modification using three-dimensional CT in total hip arthroplasty (THA) and bipolar hemiarthroplasty (BHP). We obtained a three-dimensional digital image of the metal components by widening the maximum window width, adjusting the proper cutoff threshold level, and removing the metal artifact. The centric coordinates of both the metal-backed cup and the femoral head were calculated from this image. Modification was defined as a change in distance between those two points from their original interval. Phantom studies of the accuracy and reproducibility of the method indicated that the average error ranged from 0.02 to 0.12mm and the standard deviation ranged from 0.01 to 0.05mm. Clinical in vivo measurement was performed without error of computer software on 19 hips in which modification of highly cross-linked polyethylene components was significantly large.  相似文献   
82.
We report a patient with antithyroid drug-induced progressive bilateral sensorineural hearing loss associated with myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA). While antithyroid drugs have been linked to MPO-ANCA-associated small-vessel vasculitis, sensorineural hearing loss rarely was noted. A 36-year-old man treated for hyperthyroidism with propylthiouracil (PTU) developed progressive bilateral sensorineural hearing loss accompanied by fever and arthritis. MPO-ANCA were demonstrated in serum. Distortion product otoacoustic emissions test results suggested dysfunction of outer hair cells of the organ of Corti. Inner ear blood flow impairment from ANCA-associated small-vessel vasculitis presumably caused cochlear dysfunction. PTU withdrawal and high-dose methylprednisolone administration greatly improved hearing on both sides.  相似文献   
83.
PURPOSE: To describe the clinical characteristics of a Japanese male patient with enhanced S-cone syndrome (ESCS) and investigate the existence of mutations in the NR2E3 gene, which encodes a photoreceptor cell-specific nuclear receptor. METHODS: Fundus examinations, fluorescein angiography, colour vision tests, spectral sensitivity, and full-field and spectral electroretinography were performed. Mutation screening of the NR2E3 gene was performed with polymerase chain reaction (PCR) amplification and direct sequencing. RESULTS: We identified a novel homozygous mutation (c.1048C > T), that converts glutamine (CAA) to a termination codon (TAA) at amino acid position 350. The subject's unaffected parents were heterozygous for the mutation, consistent with autosomal recessive transmission. The electroretinographic findings revealed that the patient had neither rod nor 30-Hz flicker responses but did have cone responses with large a-wave and low b-wave amplitudes, similar to the rod-plus-cone responses, and also substantial short wavelength-sensitive (S) cone and extremely diminished long/middle wavelength-sensitive (L/M) cone responses. In the right eye, spectral sensitivity in the fovea revealed both functional S-cone and remarkably reduced L- and M-cone sensitivities, which was compatible with the decreased visual acuity (VA) and red/green colour vision defects noted in this eye. In contrast, the patient had good VA and normal red/green colour vision in the left eye. CONCLUSION: The nonsense mutation results in a truncated NR2E3 protein lacking 61 amino acids within the ligand-binding domain (LBD) that consists of 190 amino acids of the C-terminus end. Therefore, null function of the LBD is likely to cause ESCS in the patient. The clinical findings for this patient suggest that his left eye, with its functional L/M- and S-cones, was at an earlier stage of the syndrome than his right eye.  相似文献   
84.
Today 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are the most often prescribed drugs among the therapeutics for hypercholesterolemia. Pitavastatin is a novel statin that has been developed entirely in Japan from the biological screening to clinical studies persuing more efficatious statin than hitherto known. Preclinical studies on drug metabolism revealed that pitavastatin is distributed selectively to the liver, excreted into bile without metabolic modification, and efficiently re-circulates to the liver to show a prolonged plasma half-life. In guinea pigs, pitavastatin enhanced hepatic LDL receptor activity and reduced VLDL secretion in a liver perfusion study, and it lowered plasma total cholesterol (TC) levels at 0.3 mg/kg and triglyceride (TG) levels at 1 mg/kg, respectively, and more. From these results, pitavastatin is assumed to lower LDL cholesterol (LDL-C) by promoting LDL receptor expression and further potentiate the cholesterol-lowering effect and exert TG-lowering effect by reducing VLDL secretion. (14)C-Pitavastatin is metabolized with CYP2C9 to 8-hydroxy derivative, but its Vmax /Km was about 2 micro l/min/mg, about 1/8 to 1/100 in comparison to the reported values of other statins, indicating that pitavastatin is hardly metabolized. Also, other human P450 species were not inhibited by pitavastatin. Therefore, pitavastatin is considered to have little interaction with drugs through P450. In the summarized clinical results with 862 patients, pitavastatin lowered TC and LDL-C by 28% and 40%, respectively. There was no difference in the frequency of side effects and no serious adverse effect was observed for pitavastatin. Pitavastatin possesses superior plasma lipid-improving effects, induces little drug interaction, and is expected to make a good contribution to the medication of hypercholesterolemia.  相似文献   
85.
The jugular bulb may be present in different positions and dimensions within the temporal bone. In general, high jugular bulbs were classified into 2 types: lateral in which the jugular bulb protrudes into the middle ear and up into the tympanic cavity and medial in which the jugular bulb is abnormally placed more superiorly and medial to the cochlea. We report, a unique case of a high jugular bulb which came round from behind of the internal auditory canal and the cochlea protruding into the posterosuperior part of the mesotympanum. It was a very rare pattern of a high jugular bulb which varies in position. The occurrence of adhesive otitis media caused the high jugular bulb to bleed easily in the only hearing ear. There would be risks of making the patient suffer severe bilateral healing impairment due to only one hearing ear and excessive hemorrhage in surgical treatment. With only one hearing ear, we should therefore select transcatheter interventional angiography when the quantity and frequency of bleeding from the jugular bulb increase so.  相似文献   
86.
87.
88.
Fifteen commercial samples of citrus fruits grown in Japan were analyzed for their sugar contents by high-performance anion-exchange chromatography (HPAEC) and electrochemical detection (ED) coupled with a stationary phase D10 column prepared using chloromethylated styrene-divinylbenzene copolymer and N,N,N',N'-tetramethyldiaminodecane. Myo-inositol, glucose, fructose, and sucrose in all of these various citrus fruits could be successfully separated within 25 min using 0.5 M NaOH eluent at a flow-rate of 0.4 mL/min. Myo-inositol, as a better nutritional source, was found in all the citrus fruits grown in Japan (0.7 +/- 0.04-2.1 +/- 0.2 g/L). The sugar contents of twelve citrus fruits grown in other countries were also determined.  相似文献   
89.
A 67-year-old man with gallbladder cancer was treated by cholecystectomy and extrahepatic bile duct resection with regional lymph node dissection. At 10 months after surgery, CT demonstrated para-aortic lymph node recurrence. Single drug chemotherapy of UFT at 400 mg was started. After one month, the lymph node recurrence could not be detected by CT. UFT may be the primary candidate for chemotherapy for lymph node recurrence of gallbladder cancer.  相似文献   
90.
We retrospectively investigated the efficacy and feasibility of concurrent chemoradiotherapy for patients with severe dysphagia caused by oesophageal squamous cell carcinoma. Concurrent chemoradiotherapy was performed in 57 patients with T3 or T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil (5-FU) 400 mg m(-2) 24 h(-1) on days 1-5 and 8-12, combined with 2-h infusion of cisplatin (CDDP) 40 mg m(-2) on days 1 and 8. Radiation treatment at a dose of 30 Gy in 15 fractions of the mediastinum was administered concomitantly with chemotherapy. A course schedule with 3-week treatment and a 1 to 2-week break was applied twice, with a total radiation dose of 60 Gy, followed by two or more courses of 5-FU and CDDP. In all, 24 patients (42%) achieved a complete response, and the 3-year survival rate was 19%. Major toxicities were leukocytopenia and oesophagitis, and there were two (4%) treatment-related deaths. In contrast, 22 patients with T3 disease survived longer than 35 patients with T4 disease (P=0.001); however, the survival rate in 15 patients with M1 LYM disease did not differ significantly from that in 42 patients without M1 LYM disease (P=0.3545). Our results indicate that definitive chemoradiotherapy is potentially curative for locally advanced oesophageal carcinoma with malignant stricture. The efficacy and survival of patients treated with this regimen are related to the T factor.  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