首页 | 官方网站   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   2360篇
  免费   193篇
  国内免费   4篇
医药卫生   2557篇
  2023年   13篇
  2022年   21篇
  2021年   56篇
  2020年   33篇
  2019年   51篇
  2018年   51篇
  2017年   47篇
  2016年   52篇
  2015年   62篇
  2014年   77篇
  2013年   89篇
  2012年   123篇
  2011年   137篇
  2010年   72篇
  2009年   51篇
  2008年   108篇
  2007年   115篇
  2006年   117篇
  2005年   100篇
  2004年   112篇
  2003年   91篇
  2002年   75篇
  2001年   82篇
  2000年   89篇
  1999年   81篇
  1998年   26篇
  1997年   34篇
  1996年   22篇
  1995年   23篇
  1994年   17篇
  1993年   11篇
  1992年   50篇
  1991年   53篇
  1990年   44篇
  1989年   37篇
  1988年   30篇
  1987年   38篇
  1986年   33篇
  1985年   20篇
  1984年   20篇
  1983年   13篇
  1982年   11篇
  1979年   18篇
  1977年   13篇
  1976年   11篇
  1975年   14篇
  1974年   10篇
  1972年   18篇
  1971年   15篇
  1970年   17篇
排序方式: 共有2557条查询结果,搜索用时 15 毫秒
1.
2.
The evidence of thyroid vascular anomalies is is frequent and may manifest itself with an anatomic alteration. The absence of the inferior thyroid artery is reported in 1% of the cases, while a thyroid artery arising from the common carotid artery has been found in 2% of examined patients. In the observed case we retain that the rarity is not only due to the contemporary presence of two anomalies, but also to the presence of an anomalous vessel which arises from right carotideal bifurcation and bloody supplies either right lobular or left lobular of thyroid, thus resulting the sole gland's arterial vessel.  相似文献   
3.
The aim of the study was to evaluate the applicability to urine samples of the AmplifiedMycobacterium tuberculosis Direct Detection Test (AMTD), which is currently used to identify this organism in respiratory specimens within a few hours. The study was performed on 95 patients, comprising 35 subjects with a high index of suspicion for active tuberculosis of the urinary tract and 60 subjects with evidence of non-mycobacterial disease. One urine specimen from each subject was examined by microscopy, culture and AMTD. AMTD was positive in 38 specimens and negative in 57. Assuming culture as the reference standard, the sensitivity, specificity, positive predictive value and negative predictive value of AMTD were 100%, 91.93%, 86.84% and 100%, respectively. Reassessing the discrepancies between AMTD and culture by review of patients' charts, the sensitivity, specificity, positive predictive value and negative predictive value of AMTD were 100%, 93.44%, 89.47% and 100%. The results of the study as well as the characteristics of AMTD encourage its use for the rapid recognition of urinary tract tuberculosis, although its findings should be interpreted cautiously when the clinical picture is not consistent with an active tuberculosis.  相似文献   
4.
BACKGROUND. Structural hemoglobinopathies usually are inherited as autosomic dominant traits; de novo mutations are uncommon. Analytical and preparative procedures for the characterization of an abnormal hemoglobin are complex and time-consuming. Mass spectrometer analysis allows a rapid identification of the amino acid substitution. METHODS AND RESULTS. A cyanotic 7-year-old girl was found to have 16% methemoglobin. Laboratory data showed the presence of an abnormal hemoglobin, which was isolated by collecting the abnormal peak from DEAE and globin chains from CM52. The amino acid substitution was rapidly identified by FAB mass spectroscopic analysis, leading to the recognition of HbM Hyde Park. These data were confirmed by molecular analysis (Southern blot and DNA sequencing). Neither the parents nor a sister showed any abnormality; non-paternity was excluded by blood group serology and HLA typing. CONCLUSIONS. This is a case of HbM Hyde-Park arising as a de novo mutation. FAB mass spectroscopic analysis is a rapid and useful analytical method for identifying aminoacid substitution.  相似文献   
5.
Thirty-one patients with advanced non-small-cell lung cancer (NSCLC) were treated with a combination of folinic acid, fluorouracil, vincristine, and mitomycin (F-FOMi). Eight partial responses (26%), eight stable disease (26%), and 15 progressive disease (48%) were obtained. Patients with performance status (PS) 0-1 had a significantly better response rate than those with PS 2-3. Overall actuarial survival was 10 months. Toxicity was mild and mainly gastrointestinal with mucositis and diarrhea. F-FOMi seems to be comparable to regimens more widely used in the treatment of NSCLC.  相似文献   
6.
7.
8.
Summary:  Purpose: Temporal lobe epilepsy (TLE) is probably more difficult to recognize in children than in adults. In fact, ictal symptoms in children are less stereotyped and less obvious, and the neuropathological substrate is more heterogeneous than in adults. The aim of this study is to examine the relationships between etiology, age at onset and electroclinical findings in 77 children with TLE, 32 of whom were surgically treated.
Methods: Electroclinical study including video-EEG recording of seizures in 77 children with TLE. The investigation focused on the first five initial ictal symptoms.
Results: Age at onset was less than 3 years in 39 cases, between 3 and 6 years in 17 cases and older than 6 years in 21 cases. Auras also occurred in younger children but were more common after the age of 6 years. A peculiar initial ictal semiology consisted in staring with arrest, lip cyanosis, and very slight oral automatisms. In some cases, EEG recordings documented seizures starting independently on both temporal lobes. Based on electroclinical and neuroradiological features, we recognized three subgroups: symptomatic TLE due to cortical malformations or nonevolutive tumors, TLE with mesial temporal sclerosis, and cryptogenic TLE.
Conclusions: A correct electroclinical and neuroradiological approach allows in several cases early recognition of TLE even when onset is earlier than the age of 6 years. A correct definition of the localization relies primarily on video-EEG recording of the seizures, possibly repeated during follow up in cases lacking obvious neuroradiological correlation.  相似文献   
9.
Using a corticostriatal slice preparation, we have recently shown that tetanic stimulation of the corticostriatal pathway produces long-term depression (LTD) of striatal excitatory synaptic transmission. In the present study we have analysed the relationship between LTD and the striatal release of different endogenous transmitters. Samples of perfusate were collected via a small cannula placed just above the surface of the striatal slice close to the recording electrode, and were analysed by HPLC. The high-frequency stimulation (100 Hz, three trains, 3 s duration, 20 s intervals) used to induce LTD caused a significant but transient increase in the release of both excitatory (aspartate and glutamate) and inhibitory (glycine and GABA) amino acid transmitters. Tetanic stimulation also produced a significant, but transient increase in the release of endogenous dopamine. We conclude that the tetanic stimulation of the corticostriatal pathway is able to induce a large but transient release of excitatory amino acids and of dopamine, whose participation in the induction of striatal LTD has been demonstrated previously. Moreover, the maintenance of this form of synaptic plasticity does not seem to require a sustained change in transmitter release.  相似文献   
10.
We evaluated the clinical accuracy of an automated turbidimetric assay for serum lipase determination in order to screen for acute pancreatic damage. Seventy patients with pancreatic and thirty with nonpancreatic digestive diseases were studied. Fifty-two healthy subjects were also studied as controls. Serum lipase concentrations were abnormally high in all patients with acute pancreatitis and in 3 (10%) in the group of 30 patients with nonpancreatic acute abdomen. In the 35 patients with chronic pancreatitis studied during clinical remission, serum lipase levels were abnormally high in 8 (23%), and abnormally low in 3 (9%). In the 9 patients with pancreatic cancer, 4 (44%) had abnormally elevated serum lipase values and 1 (11%) abnormally low. The results indicate that serum lipase determination is useful in the emergency diagnosis of acute pancreatic damage because of its high sensitivity and specificity. In patients with chronic pancreatitis and in patients with pancreatic carcinoma serum lipase determination is of limited value.  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-23

京公网安备 11010802026262号