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   3881篇
  免费   172篇
  国内免费   17篇
耳鼻咽喉   39篇
儿科学   309篇
妇产科学   57篇
基础医学   489篇
口腔科学   39篇
临床医学   243篇
内科学   783篇
皮肤病学   82篇
神经病学   173篇
特种医学   62篇
外科学   412篇
综合类   255篇
一般理论   4篇
预防医学   312篇
眼科学   106篇
药学   405篇
  1篇
中国医学   23篇
肿瘤学   276篇
  2024年   12篇
  2023年   18篇
  2022年   59篇
  2021年   131篇
  2020年   87篇
  2019年   92篇
  2018年   91篇
  2017年   71篇
  2016年   117篇
  2015年   94篇
  2014年   144篇
  2013年   232篇
  2012年   283篇
  2011年   286篇
  2010年   171篇
  2009年   112篇
  2008年   201篇
  2007年   200篇
  2006年   188篇
  2005年   160篇
  2004年   136篇
  2003年   138篇
  2002年   109篇
  2001年   84篇
  2000年   58篇
  1999年   46篇
  1998年   34篇
  1997年   23篇
  1995年   13篇
  1992年   51篇
  1991年   52篇
  1990年   45篇
  1989年   42篇
  1988年   35篇
  1987年   35篇
  1986年   26篇
  1985年   22篇
  1984年   14篇
  1979年   30篇
  1978年   15篇
  1977年   21篇
  1976年   13篇
  1975年   13篇
  1974年   19篇
  1973年   22篇
  1972年   21篇
  1971年   13篇
  1970年   25篇
  1969年   18篇
  1968年   12篇
排序方式: 共有4070条查询结果,搜索用时 31 毫秒
31.
Candida spp have often been reported in cervical cytology, other fungal organisms are very rare in modern literature. We report nine cases of conventional cervical smears showing Penicillium, Aspergillus, and Cladosporium spp in healthy imunocompetent females. Penicillium spp seen in four out of nine smears, Cladosporium spp alone in three out of nine smears, and Cladosporium spp along with Aspergillus spp in two out of nine smears. A detail of these nine cases is presented with discussion on importance of these structures when observed in conventional cervical smears. Awareness of such contaminants is important to differentiate from true infection for relevant therapeutic implications. A systematic step‐wise approach to such structures is also suggested. Diagn. Cytopathol. 2015;43:234–237. © 2014 Wiley Periodicals, Inc.  相似文献   
32.
The aim of this study was to investigate the morphologic and ultrastructural features of biofilms of slow and fast-growing mycobacteria in different stress conditions, presence and absence of oleic acid albumin dextrose catalase (OADC) enrichment and at different temperatures: 30, 37 and 42?°C. Four hundred mycobacterial isolates were taken. The biomass of each biofilm was quantified using a modified microtiter plate assay method. Isolates were divided into those that formed fully established biofilms, moderately attached biofilms and weakly adherent biofilms by comparison with a known biofilm-forming strain. The large quantity of biofilm was produced by Mycobacterium smegmatis at temperature 37 and 42?°C as compared to 30?°C. Mycobacterium fortuitum and M. avium developed large amount of biofilm at 30?°C as compared to 37 and 42?°C. Mycobacterium tuberculosis developed strong biofilm at 37?°C and no biofilm at 30 and 42?°C in Sauton’s media. The selected non-tuberculous mycobacteria and H37Rv developed strong biofilm in the presence of OADC enrichment in Sauton’s medium. Microscopic examination of biofilms by scanning electron microscopy revealed that poorly adherent biofilm formers failed to colonize the entire surface of the microtiter well. While moderately adherent biofilm formers grew in uniform monolayers but failed to develop a mature three-dimensional structure. SEM analysis of an isolate representative of the group formed fully established biofilms with a textured, multi-layered, three-dimensional structure.  相似文献   
33.
AIMS—To compare the clinical efficacy of hypo-osmolar oral rehydration salt (ORS) solution (224 mmol/l) and standard ORS solution (311 mmol/l) in severely malnourished (marasmic) children having less than 60% Harvard standard weight for age with dehydrating acute watery diarrhoea.
METHODS—In a double blind, randomised, controlled trial, 64 children aged 6-48 months were randomly assigned standard (n = 32) or hypo-osmolar ORS (n = 32).
RESULTS—Stool output (52.3 v 96.6 g/kg/day), duration of diarrhoea (41.5 v 66.4 hours), intake of ORS (111.5 v 168.9 ml/kg/day), and fluid intake (214.6 v 278.3 ml/kg/day) were significantly less in the hypo-osmolar group than in the standard ORS group. Percentage of weight gain on recovery in the hypo-osmolar group was also significantly less (4.3 v 5.4% of admission weight) than in the standard ORS group. A total of 29 (91%) children in the standard ORS group and 32 (100%) children in the hypo-osmolar group recovered within five days of initiation of therapy. Mean serum sodium and potassium concentrations on recovery were within the normal range in both groups.
CONCLUSION—Our findings suggest that hypo-osmolar ORS has beneficial effects on the clinical course of dehydrating acute watery diarrhoea in severely malnourished (marasmic) children. Furthermore, children did not become hyponatraemic after receiving hypo-osmolar ORS.

  相似文献   
34.
35.
The preterm very low birth weight infants are at high risk of developing neurodevelopmental delay despite little or no medical complications at the time of birth. The care and interventions of such infants have an impact on the pre-existing risk. The Developmental Care Interventions (DCI) are the range of treatment strategies aiming to alleviate the risk thereby improving neuro-developmental outcomes. The objective of this review is to appraise the range of such interventions for preterm very low birth weight infants reported in the literature. This review will help clinicians to adopt developmental intervention strategy to improve the neuro-developmental outcomes of their NICU graduates.  相似文献   
36.

Objective

To compare plain soap, alcohol hand rub and iodophors as hand hygiene measures in a neonatal intensive care unit (NICU).

Design

Randomized, crossover, three-armed, controlled trial with blinded outcome measurement

Setting

Level III NICU

Participants

35 NICU nurses

Intervention

Participants were assigned to plain soap hand washing, alcohol hand rub and povidone-iodine hand scrub by a random cross-over design. Interventions were preceded by 14-day neutral periods. Cultures from hands were taken before and after each hand-hygiene use, prior to 5 patient-care activities.

Main outcome measure

The primary outcome was mean posthygiene colony forming unit count (CFU-C).

Results

There were differences between soap, alcohol and povidone groups vis-à-vis post-hygiene CFU-C [median: 60, 8 and 10.5, respectively (P<0.001)], absolute reduction in CFU-C [median: 15, 100 and 40, respectively (P<0.001)], percent reduction in CFU-C [median: 33.3, 92 and 87, respectively (P<0.001)] and proportion with “low CFU-C” [47%, 71% and 72%, respectively (P<0.001)]. Alcohol [Adjusted OR 3.2 (95% CI 1.9, 5.3)], povidone-iodine [AOR 3.1 (95% CI 1.8, 5.3)] and high prehygiene CFU-C (>300) [AOR 0.18 (95% CI 0.1, 0.3)] were independently associated with “low CFU-C”.

Conclusions

After a 2-minute hand wash at entry into NICU, alcohol hand rub and povidone-iodine scrub are superior to plain soap hand wash for subsequent decontamination of hands of nurses working in NICU.  相似文献   
37.

Objective

To evaluate the etiology, presentation, complications and management of chronic pancreatitis in children.

Design

Retrospective chart review.

Setting

Gastroenterology department at Christian Medical College and Hospital, Vellore, India between January 2005 and December 2010.

Participants

99 Children (<18 yrs) diagnosed with chronic pancreatitis based on clinical and imaging features.

Main outcome measures

Etiology, clinical presentation, complications and management of chronic pancreatitis in children.

Results

Of 3887 children who attended the Gastroenterology department, 99(2.5%) had chronic pancreatitis, of which 60 (60.6%) were males. In 95(95.9%) patients no definite cause was detected and they were labeled as Idiopathic chronic pancreatitis. All patients had abdominal pain, while 9(9.1%) had diabetes mellitus. Of the 22 children tested for stool fat, 10(45.5%) had steatorrhea. Pancreatic calcification was seen in 69 (69.7%). 68 (71.6%) patients with idiopathic chronic pancreatitis had calcification. Calcific idiopathic chronic pancreatitis was more frequent in males (67.6% vs. 48.1%, P=0.07), and was more commonly associated with diabetes mellitus (13.2% vs. none, P=0.047) and steatorrhea (61.5% vs. 16.7%, P=0.069). Pseudocyst (17.1%) and ascites (9.1%) were the most common complications. All children were treated with pancreatic enzyme supplements for pain relief. 57 patients were followed up. With enzyme supplementation, pain relief was present in 32 (56.1%) patients. Of those who did not improve, 10 underwent endotherapy and 15 underwent surgery. Follow up of 8 patients who underwent endotherapy, showed that 5 (62.5%) had relief. Follow up of 11 patients who underwent surgery showed that only 3 (27 %) had pain relief. There was no death.

Conclusions

Idiopathic chronic pancreatitis is the predominant form of chronic pancreatitis in children and adolescents. It can present with or without calcification. The calcific variety is an aggressive disease characterized by early morphological and functional damage to the pancreas.  相似文献   
38.

Objective

To study the prevalence of celiac disease in Indian children with Down syndrome and evaluate its clinical and laboratory predictors.

Methods

Prevalence of celiac disease (CD) was assessed in 100 patients with Down syndrome (DS) attending pediatric genetic clinic at All India Institute of Medical Sciences,in a prospective observational study, based on the characteristic symptomatology, positive indirect immunofluorescence anti endomyseal antibody(anti EMA) test and duodenal histology based on adapted Marsh criteria. Clinical and laboratory features were compared in children having both CD and DS and those with DS alone.

Results

Anti EMA was positive in 7 out of 100 patients screened for CD; 6 in whom the duodenal biopsy could be done showed histopathological features consistent with celiac disease. Amongst various clinical features evaluated as possible risk factors; pallor reached statistical significance (OR?=?7.04 95%CI 1.08–45.7). In addition anemia (Hb <11 g%) was significantly associated with CD (p?=?0.06).

Conclusions

The present results showed a high prevalence of CD in DS children in a tertiary hospital in India and low hemoglobin to be an important risk factor. The authors recommend that all Indian children with Down syndrome, particularly those with anemia should be screened for celiac disease.  相似文献   
39.
Competitive enzyme-linked immunosorbent assay (CELISA), mediated by a monoclonal antibody designated HybI, was developed for the diagnosis of equine monocytic ehrlichiosis. Inhibition of binding of HybI by the horse antibodies to Ehrlichia risticii was optimum at dilutions of 1:20 for serum and 1:10,000 for HybI. Mean optical densities (ODs) of positive and negative sera were 0.158 and 0.855, respectively. A comparison of ODs obtained by CELISA and indirect enzyme-linked immunosorbent assay (ELISA) indicated a marked tendency of positive and negative samples to cluster separately with respect to CELISA ODs, whereas the ELISA results displayed a continuum of ODs from negative to positive. Analysis of diagnosis by indirect fluorescent-antibody test (IFA), ELISA, and CELISA for 66 field-collected serum samples indicated that CELISA was superior to IFA and ELISA. Among 11 acute-phase serum samples negative by IFA which were obtained from horses that subsequently seroconverted, CELISA clearly demonstrated antibodies in 8 of these acute-phase sera, whereas 5 were borderline positive by ELISA. The presence of agent-specific humoral antibodies could be demonstrated conclusively by 14 days after infection. The results suggest that CELISA is more sensitive than IFA and ELISA and, owing to the marked differences between positive and negative samples, can be easily adapted for use in the field for detection of horse antibodies to E. risticii.  相似文献   
40.
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