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   598篇
  免费   43篇
耳鼻咽喉   10篇
儿科学   20篇
妇产科学   9篇
基础医学   71篇
口腔科学   29篇
临床医学   59篇
内科学   136篇
皮肤病学   5篇
神经病学   79篇
特种医学   17篇
外科学   76篇
综合类   1篇
预防医学   30篇
眼科学   3篇
药学   63篇
中国医学   5篇
肿瘤学   28篇
  2023年   2篇
  2022年   6篇
  2021年   23篇
  2020年   11篇
  2019年   18篇
  2018年   15篇
  2017年   14篇
  2016年   7篇
  2015年   16篇
  2014年   22篇
  2013年   38篇
  2012年   45篇
  2011年   44篇
  2010年   39篇
  2009年   22篇
  2008年   44篇
  2007年   38篇
  2006年   27篇
  2005年   32篇
  2004年   30篇
  2003年   20篇
  2002年   20篇
  2001年   14篇
  2000年   17篇
  1999年   12篇
  1998年   3篇
  1996年   2篇
  1995年   3篇
  1992年   1篇
  1991年   7篇
  1990年   1篇
  1989年   1篇
  1988年   4篇
  1987年   5篇
  1986年   4篇
  1985年   8篇
  1984年   3篇
  1983年   4篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1972年   2篇
  1971年   1篇
  1968年   1篇
  1963年   1篇
  1906年   1篇
排序方式: 共有641条查询结果,搜索用时 15 毫秒
1.
Partial nephrectomy is the mainstay of treatment for localized kidney cancer. A proportion of patients are upstaged post-operatively to locally advanced di  相似文献   
2.
We investigated the effects of the noble gas argon on the expression of locomotor sensitization to amphetamine and amphetamine-induced changes in dopamine release and mu-opioid neurotransmission in the nucleus accumbens. We found (1) argon blocked the increase in carrier-mediated dopamine release induced by amphetamine in brain slices, but, in contrast, potentiated the decrease in KCl-evoked dopamine release induced by amphetamine, thereby suggesting that argon inhibited the vesicular monoamine transporter-2; (2) argon blocked the expression of locomotor and mu-opioid neurotransmission sensitization induced by repeated amphetamine administration in a short-term model of sensitization in rats; (3) argon decreased the maximal number of binding sites and increased the dissociation constant of mu-receptors in membrane preparations, thereby indicating that argon is a mu-receptor antagonist; (4) argon blocked the expression of locomotor sensitization and context-dependent locomotor activity induced by repeated administration of amphetamine in a long-term model of sensitization. Taken together, these data indicate that argon could be of potential interest for treating drug addiction and dependence.  相似文献   
3.
4.
Forty consecutive adult patients under the age of 50 with acute non-lymphoblastic leukemia (ANLL) in first complete remission, underwent autologous bone marrow transplantation (ABMT) between March 1984 and April 1990. The conditioning regimen employed included cyclophosphamide and total body irradiation, followed by the administration of unpurged ABMT. The median time from diagnosis to transplant was 7 months (3-15 months), and the median time from complete remission to ABMT was 4 months (range 3-9 months). Twenty-two (51%) patients remain in complete remission 6-81 months (median 24 months) after ABMT.

The causes of death were, recurrent leukemia (11 patients), parenchymal toxicities such as acute respiratory distress syndrome and veno-occlusive disease (3 patients), hemorrhage (2 patients) and infection (2 patients). Eleven patients relapsed after 3-12 months (median 5 months). This study has produced survival data comparable to those of other institutions employing TBI for either allo or autotransplants.  相似文献   
5.
We report the case of a 67-year-old man with a granular, cauliflower-pink lesion on the skin of the thigh. Histopathological study showed a typical verrucous carcinoma associated with a syringadenoma papilliferum. To our knowledge this association has not been previously reported.  相似文献   
6.
Using an electrical stimulation of the reticulospinal tract at the level of the medial longitudinal fasciculus, the effects, and the neurochemical mechanisms of these effects, of a progressive increase in helium-oxygen pressures, up to 50 bar, on the spinal cord excitability in the chronic rat are investigated. In control animals, high pressure exposure over 30 bar was found to increase markedly the electromyogram response evoked in nuchal muscles. This startlelike response was monosynaptically induced by stimulation of the reticulospinal tract. Conversly, no hyperbaric alteration in spinal excitability has been observed in animals pretreated with the classical 5-HT antagonist drug metergoline. These results emphasize the importance of spinal cord as a potential target for mediating hyperbaric effects on sensorimotor behaviors (i.e., motor disturbances of the HPNS). Moreover, our work suggests that serotonin could be implicated in hyperbaric spinal cord hyperexcitability.  相似文献   
7.
Objectives

Despite the obstacles of limited education and employment opportunities—and the stress associated with immigration and pregnancy—Mexican immigrant women have low rates of preterm birth (PTB) compared to the US national average for all races and ethnicities. Stressors during pregnancy, and stressors associated with acculturation, may accelerate cellular aging manifested by shortened telomere length (TL) in pregnant women. Our objectives were to: (1) determine whether women with PTBs had shorter telomere lengths compared to women who had full term births; (2) assess the association of acculturation with TL and PTB.

Methods

This prospective pilot study collected data from 100 self-identified Mexican-origin pregnant women. Survey data included self-administered sociodemographic and acculturation measures and was collected from participants via paper and pen, while biologic data was collected via a single blood draw during a regularly scheduled prenatal visit between 26 and 36 weeks gestation. PTB data was collected from the participant’s medical record after delivery.

Results

TL was significantly associated with PTB; the median TL of the women with PTB was less than the median TL for the full sample (p?=?0.02). Based on regression analysis for PTB vs acculturation, we found no significant associations between acculturation and PTB or TL.

Conclusions for Practice

This study provides important evidence of the association between shortened maternal TL and adverse birth outcomes. By linking social, clinical and biologic data, we can enhance our understanding of social determinants that may affect racial and ethnic disparities in preterm birth.

  相似文献   
8.
Background:A worldwide personal protection equipment (PPE) shortage has emerged during COVID-19 pandemic, contributing to the high incidence of SARS-CoV-2 infection among health care providers. To address this lack of PEE, new solutions have been researched. Among those, full-face snorkeling masks demonstrated to be an interesting option. Among surgical specialties otolaryngologists and thoracic surgeons are at high risk of infection, due to the close contact with airway secretions.Objectives:We tested the comfort and usability of a modified full-face snorkeling mask (Ocean Reef Mask Aria QR+) as a protective device for otolaryngologic and thoracic surgeries.Methods:The mask was customized with a 3D-printed adaptor supporting many industrial filter types, including FFP3 and heat and moisture exchangers (HME). We evaluated surgical performances of the mask, both subjectively, with a questionnaire filled in by the surgeons, as well as objectively, monitoring transcutaneous PCO2 and PO2 values of surgeons during surgical procedures.Results:The modified full-face snorkeling mask was tested during 9 otolaryngologic and 15 thoracic surgery procedures. The device demonstrated very good overall vision quality with some limitations regarding lateral vision and almost no difficulties in usability. Water condensation into the mask was absent in almost every case. Both PO2 and PCO2 parameters remained within normal ranges during every procedure.Discussion:The modified full-face snorkeling mask can be an innovative PPE. In the current COVID-19 pandemic scenario, the worldwide shortage of protective masks and goggles may exploit this ready-to-use and low-cost solution, especially for high-risk surgical procedures.  相似文献   
9.
It is commonly assumed that early emotional signals provide relevant information for social cognition tasks. The goal of this study was to test the association between (a) cortical markers of face emotional processing and (b) social-cognitive measures, and also to build a model which can predict this association (a and b) in healthy volunteers as well as in different groups of psychiatric patients. Thus, we investigated the early cortical processing of emotional stimuli (N170, using a face and word valence task) and their relationship with the social-cognitive profiles (SCPs, indexed by measures of theory of mind, fluid intelligence, speed processing and executive functions). Group comparisons and individual differences were assessed among schizophrenia (SCZ) patients and their relatives, individuals with attention deficit hyperactivity disorder (ADHD), individuals with euthymic bipolar disorder (BD) and healthy participants (educational level, handedness, age and gender matched). Our results provide evidence of emotional N170 impairments in the affected groups (SCZ and relatives, ADHD and BD) as well as subtle group differences. Importantly, cortical processing of emotional stimuli predicted the SCP, as evidenced by a structural equation model analysis. This is the first study to report an association model of brain markers of emotional processing and SCP.  相似文献   
10.
Abstract: Background/Aims: Hepatitis C virus (HCV) related disease follows a long, benign course and most affected patients have mild disease. Liver biopsy is mandatory to grade and stage the disease. Characteristic, though non-specific, HCV histological lesions such as bile duct damage and steatosis have been singled out but their association with non-histological parameters has not been completely defined. Our aim was to study the relationships among these histological lesions and clinical, biochemical, functional and virological characteristics in a group of Northern Italian patients with chronic hepatitis. Methods: We studied 172 patients with HCV-related chronic hepatitis. Patients were divided into groups on the basis of histology including bile duct damage and steatosis. Clinical, biochemical, functional and virological profiles were related to histological findings. Results: Histological grading and staging of disease increased as the age of patients increased. Steatosis was present in 70% of our patients and was related to a higher degree of fibrosis and to decreased functional activity. The prevalence of bile duct damage was 20%. This lesion was present in older patients with higher staging and impaired liver function. Biochemically it was associated with an increase in aspartate aminotransferase, gammaglutamyltranspeptidase, alkaline phosphatase, and total bilirubin. Conclusions: In the population we studied, HCV chronic hepatitis was predominantly a mild disease. Moreover both steatosis and bile duct damage were also mild. Steatosis was associated with fibrosis and this might influence liver metabolic function. Bile duct lesions were found in older patients with advanced disease showing biochemical evidence of cholestasis. The molecular role HCV might play in the pathogenesis of these histological features should be addressed in further studies.  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