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   1327篇
  免费   78篇
  国内免费   2篇
耳鼻咽喉   21篇
儿科学   42篇
妇产科学   4篇
基础医学   136篇
口腔科学   11篇
临床医学   139篇
内科学   384篇
皮肤病学   64篇
神经病学   111篇
特种医学   68篇
外科学   228篇
综合类   7篇
预防医学   37篇
眼科学   13篇
药学   54篇
肿瘤学   88篇
  2023年   29篇
  2022年   32篇
  2021年   43篇
  2020年   32篇
  2019年   50篇
  2018年   49篇
  2017年   35篇
  2016年   42篇
  2015年   51篇
  2014年   91篇
  2013年   70篇
  2012年   82篇
  2011年   69篇
  2010年   50篇
  2009年   55篇
  2008年   85篇
  2007年   73篇
  2006年   70篇
  2005年   64篇
  2004年   46篇
  2003年   47篇
  2002年   40篇
  2001年   26篇
  2000年   17篇
  1999年   17篇
  1998年   4篇
  1997年   10篇
  1996年   6篇
  1995年   8篇
  1994年   3篇
  1992年   13篇
  1991年   9篇
  1990年   9篇
  1989年   5篇
  1988年   7篇
  1987年   7篇
  1986年   5篇
  1985年   4篇
  1984年   6篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1979年   4篇
  1976年   3篇
  1971年   2篇
  1970年   3篇
  1969年   2篇
  1967年   3篇
  1966年   2篇
  1960年   3篇
排序方式: 共有1407条查询结果,搜索用时 0 毫秒
81.
Book M  Lehmann LE  Schewe JC  Weber S  Stüber F 《Der Urologe. Ausg. A》2005,44(4):413-22; quiz 423-4
Urosepsis is defined as sepsis caused by urinary tract infection. This occurs in 25% of all sepsis cases. Because of the increasing incidence of sepsis, this entity will be seen more frequently in medical practice and outpatient units. The immediate identification and treatment of the septic focus is crucial. Depending on severity, early reconstitution of adequate oxygen delivery has parallel priority, therefore necessitating intensive care unit treatment within the first hours. Therapy should consist of eliminating the infectious focus, antimicrobial treatment, supportive therapy, and special sepsis therapy.  相似文献   
82.
Lipopolysaccharides (LPSs) play a dual role as target and as effector molecules. The knowledge of the LPS-induced activation of human immune cells is increasing; however, surprisingly, much less effort seems to be directed towards the understanding of the mechanisms leading to the killing of the bacterial organisms, which eventually results in the release of LPS from the bacterial surface into the blood circulation. We demonstrate mechanisms of interaction of peptides of the innate immune system (e.g. defensins and cathelicidins) as well as of externally administered antibiotics (e.g. Polymyxin B) with Gram-negative bacteria. The main focus is directed on data derived from electrical measurements on a reconstitution system of the outer membrane as an asymmetric bilayer composed on one side of LPS and on the other of phospholipids. All these antimicrobial peptides (AMPs) are membrane-active and induce the permeabilization of the reconstituted membranes by the formation of lesions. We found that differences in the activity of the AMPs against various sensitive and resistant Gram-negative bacteria can be explained solely by variations in the chemical structure of LPS, e.g. in the composition of the sugar head group. A reduction of the net negative charge of LPS is responsible for a reduced interaction with the polycationic AMPs and thus for resistance. A most important side effect of positively charged AMPs is the neutralization of the negatively charged LPS released from the bacterial surface as a consequence of AMP-induced killing.  相似文献   
83.
84.
OBJECTIVES: The intestinal flora of breast-fed infants is generally dominated by Bifidobacteria. We aimed to investigate whether an infant formula supplemented with galacto-oligosaccharides and fructo-oligosaccharides (GOS/FOS) is able to establish a bifido-dominant microflora, not only in numbers but also with respect to the metabolic activity in the colon. METHODS: Two groups of infants fed infant formula with 0.8 g/100 ml GOS/FOS in a ratio of 9:1 (OSF group), or control formula (SF group) were evaluated in a randomised, double blind, placebo controlled intervention study. A breast-fed group was studied in parallel. At study onset and after 4 and 6 weeks, faecal samples were examined for the number of bifidobacteria, pH, short chain fatty acids and lactate. RESULTS: After 6 weeks, the mean proportion of bifidobacteria was significantly higher in the OSF group (59.6% versus 49.5% in the SF group; P < 0.05). Compared with controls, infants in the OSF group had a lower stool mean pH and an increased proportion of acetate and a decreased proportion of propionate. The mean pH in the OSF and SF groups were 5.7 and 6.3, respectively (P < 0.001). CONCLUSIONS: The addition of the prebiotic GOS/FOS mixture to an infant formula has a stimulating effect on the growth of bifidobacteria and on the metabolic activity of the total intestinal flora. The changes in short chain fatty acids, lactate and pH in the prebiotic group represent a fermentation profile that is closer to that observed in breast-fed infants compared to infants fed control formula.  相似文献   
85.
86.
Despite the remarkable clinical response rates to imatinib in the treatment of bcr-abl leukemic patients, pharmacokinetic data on this relatively novel substance are needed to improve our understanding of the emergence of resistance, the interindividual variations of clinical response and the clinical and biologic relevance of its main metabolite N-desmethyl-imatinib. We present here pharmacokinetic data obtained with a newly designed HPLC approach in 97 patients with chronic myeloid leukemia or acute lymphatic leukemia (ALL) under treatment with imatinib that allowed us to calculate the AUC (39.5 g·h/ml for an oral dose of 400 mg daily), the t1/2 (18.2 h) and the peak concentration (1.92 /ml for an oral dose of 400 mg daily) of imatinib in plasma. In a subgroup of patients, the same parameters were analyzed for N-desmethyl-imatinib. We also provide data on the imatinib concentration in the cerebrospinal fluid (CSF) of ALL patients and demonstrate that oral administration of imatinib resulted only in a marginal flux across the blood-brain barrier. Finally, in an in vitro setting, we determined cellular concentrations of imatinib in HL-60 cells and showed an over-proportional uptake both in RPMI medium and in human plasma. Using an arithmetical approach combining all parameters obtained in imatinib-treated patients, we finally provide a conclusive approximation of basic pharmacokinetic data for both imatinib and its main metabolite N-desmethyl-imatinib.  相似文献   
87.
PURPOSE: Valproic acid (VPA) is commonly used as an antiepileptic drug (AED). Regular screening for renal side effects is uncommon. Fanconi syndrome, a generalized dysfunction of renal proximal tubular cells, occurs with some inborn errors of metabolism. In addition, it can be acquired by exposure to several toxic substances. We report a case of Fanconi syndrome after long-term therapy with VPA. METHODS: An 8-year-old severely disabled and developmentally retarded boy with epilepsy was treated with VPA over a period of 7 years. He was hospitalized after a status epilepticus with laboratory findings suggesting a Fanconi syndrome. A PubMed-based worldwide review of the literature revealed that Fanconi syndrome is a rare side effect in children during long-term VPA treatment. We analyzed all 10 previously published cases by comparing age, underlying diseases, medication, and outcome. RESULTS: Examination revealed metabolic acidosis suggestive of renal tubular malfunction. Based on typical clinical and laboratory findings, an acquired Fanconi syndrome was diagnosed. This was treated with large doses of sodium bicarbonate. After discontinuation of VPA, renal function completely normalized within 2 months. CONCLUSIONS: Fanconi syndrome appears to be a rare but severe consequence of long-term VPA therapy. Therefore patients treated with VPA should be checked regularly for the possible development of VPA-induced Fanconi syndrome.  相似文献   
88.
BACKGROUND: Recently attention has focused on the assessment of functional health status in substance-dependent individuals. The addiction severity index (ASI) is a widely used assessment instrument that includes scales to reflect current medical and psychiatric status. This study examines the concurrent validity of these ASI composite scores in relation to the short form 36-item health survey (SF-36), a well-established measure of health-related quality of life/functional health status. METHODS: Veterans (n=674) were assessed at admission to substance dependence treatment. Correlations were performed between ASI composite scores and SF-36 scales and the physical and mental summary components (PSC and MSC, respectively). Areas under receiver operating characteristic (ROC) curves determined the descriminative ability of the ASI composites to ascertain impairment. RESULTS: The ASI medical composite score demonstrated robust correlations with the four SF-36 scales that relate to physical health and with the PCS. The ASI psychiatric composite score had robust correlations with the four SF-36 scales related to mental health and with the mental component summary (MCS). ROC curves indicated that the ASI medical (AUC=0.83) and psychiatric composites (AUC=0.90) accurately detected subjects with impairment. CONCLUSIONS: ASI medical and psychiatric composite scores provide effective initial screening for patients with impaired functional status as measured by the corresponding SF-36 component summary scores.  相似文献   
89.
OBJECTIVE: To estimate the prevalence of reduced function, compared to normative values, and tenderness in the shoulder in patients with newly diagnosed rheumatoid arthritis (RA), and to investigate associated factors. METHODS: Eighty consecutive patients with RA, participating in a prospective study of early rheumatoid arthritis, were examined and assessed within one year of the onset of symptoms. RESULTS: The prevalence of tenderness from any of the shoulder joints was 50%, while 30% had decreased shoulder function, compared with age matched controls, in at least one shoulder. Both tender shoulder joints and decreased shoulder function were related to higher age and more severe disease, reflected by disability (HAQ) and the patient's assessment of pain and global disease activity. CONCLUSION: The shoulder girdle is involved early and often in rheumatoid arthritis and involvement is associated with a substantially more severe disease status. The study suggests that the shoulder should be given attention in patients with newly diagnosed rheumatoid arthritis, and that both tenderness and shoulder function should be evaluated.  相似文献   
90.
Lack of seasonal variation in C-reactive protein   总被引:13,自引:0,他引:13  
  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