全文获取类型
收费全文 | 689篇 |
免费 | 36篇 |
国内免费 | 16篇 |
专业分类
儿科学 | 45篇 |
妇产科学 | 13篇 |
基础医学 | 83篇 |
口腔科学 | 5篇 |
临床医学 | 66篇 |
内科学 | 119篇 |
皮肤病学 | 23篇 |
神经病学 | 10篇 |
特种医学 | 62篇 |
外科学 | 139篇 |
综合类 | 23篇 |
预防医学 | 46篇 |
眼科学 | 18篇 |
药学 | 53篇 |
中国医学 | 11篇 |
肿瘤学 | 25篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 21篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 21篇 |
2015年 | 21篇 |
2014年 | 26篇 |
2013年 | 38篇 |
2012年 | 49篇 |
2011年 | 28篇 |
2010年 | 39篇 |
2009年 | 23篇 |
2008年 | 18篇 |
2007年 | 27篇 |
2006年 | 34篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 23篇 |
1994年 | 12篇 |
1993年 | 16篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1966年 | 3篇 |
1947年 | 2篇 |
1943年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有741条查询结果,搜索用时 15 毫秒
31.
Sam CK Cheng BScOptom Maurice KH Yap PhD MCOptom FAAO Ernest Goldschmidt MD DrSci Peter G Swann BSc MAppSc FCOptom FAAO honFIES Larry HY Ng PDOptom OD FAAO FBCLA Carly SY Lam PhD MSc MCOptom FAAO 《Clinical & experimental optometry》2008,91(4):373-378
Background: Optomap uses the ultra‐wide field scanning laser ophthalmoscopy to provide retinal examination. It permits fundus examination without the use of a mydriatic, which is more comfortable for the patients. This paper determines the sensitivity and specificity of the Optomap for detecting retinal signs under non‐mydriatic conditions. Methods: Fifty‐four eyes identified with retinal/choroidal signs and eight normal eyes were recruited from 31 Hong Kong Chinese subjects. Photo‐documentation of fundal changes was obtained with the Optomap under non‐mydriatic conditions before a dilated fundus examination by a clinician using standard procedures. The eyelid was retracted using a cotton bud when necessary. Dilated fundus examinations were performed by another clinician using binocular indirect ophthalmoscopy and slitlamp biomicroscopy with a fundus lens. The Optomap images were evaluated by four other investigators under masked condition. The International Classification of Disease, Ninth Revision (ICD‐9‐CM) was adopted for recording retinal features. Screening results were compared with those obtained using the dilated fundus examination as the gold standard. Results: The cotton bud method for eyelid retraction showed an improvement in the area of retina that could be visualised. The sensitivity and specificity of the Optomap averaged 76.4 and 71.9 per cent, respectively. Some fundal signs were missed by all observers in the Optomap but not with the biomicroscope. These included white‐without‐pressure, lattice degeneration, paramacular drusen and pigmentary changes at central fundus. Conclusion: Optomap serves as a reliable screening tool for fundus examination especially because it covers a much wider area of the peripheral retina than other digital instruments for fundus photography. 相似文献
32.
Bohr VA Cooper M Orren D Machwe A Piotrowski J Sommers J Karmakar P Brosh R 《Experimental gerontology》2000,35(6-7):695-702
Werner syndrome is a premature aging syndrome displaying numerous signs and symptoms found in normal aging. The disease is associated with a mutation in the WRN gene. We have purified the Werner protein (WRN) and studied its biochemical activities and its protein interactions. WRN is a helicase and an exonuclease and also has an associated ATPase activity. WRN interacts physically and functionally with replication protein A (RPA), which stimulates its helicase activity. We have studied the WRN exonuclease activity and found that it can be blocked by certain DNA lesions and not by others. Thus, while WRN does not bind to DNA damage, it may have properties that allow it to sense the presence of damage in DNA. More recently we have found other protein interactions that involve physical and functional interactions with WRN, which could suggest a role for WRN in DNA repair. 相似文献
33.
There is increasing interest in the use of cuffed paediatric tracheal tubes, these tubes have a number of advantages and disadvantages. One disadvantage is the decreased margin of safety associated with the use of cuffed tracheal tubes. When using an uncuffed tube, the margin of safety is approximately the length of the trachea, however, for a cuffed tube, this margin is reduced and is the length of the trachea minus the distance between the proximal edge of the cuff and the and the tip of the tube. We have found that, compared with traditional uncuffed tubes, cuffed tubes may be associated with a reduced margin of safety of approximately 50% or more. 相似文献
34.
The anticarcinogenic effect of vitamin D3 (VD3) on 3,-methyl-4-dimethyl-amino-azobenzene (3,-Met-DAB)-induced hepatocarcinogenesis was investigated in male Sprague-Dawley rats. Anticancer efficacy of VD3 was estimated using different possible biomarkers, namely reduced glutathione (GSH) concentration, gamma-glutamyl transpeptidase (GGT) activity, glutathione S-transferase (GST) activity, glutathione reductase (GRd) activity, glutathione peroxidase (GPx) activity in hyperplastic nodules (HNs) and non-nodular surrounding parenchyma (NNSP) liver areas. VD3 was found to control the carcinogen-induced alterations in GSH level, GST, GGT, GRd and GPx activity both in HNs and NNSP liver areas during long-term exposure. A decrease in the number of HNs was also evident in the present investigation. VD3 was proved to be an effective antitumor drug during the initiation/promotion phases of hepatic carcinogenesis but the effect was found to be less prominent during initiation and promotion phases. 相似文献
35.
中国流行性乙型脑炎防制策略 总被引:7,自引:0,他引:7
流行性乙型脑炎(简称乙脑)是由携带乙脑病毒的蚊子叮咬人体引起的急性中枢神经系统传染病,是一种人畜共患的自然疫源性疾病.临床以高热、嗜睡、惊厥、昏迷、抽搐为主要表现,严重者可致死亡,部分病例可留有后遗症.近年来,我国每年的乙脑病例数波动于5000例~8000例之间,在法定传染病排序中位于前10位以外,其死亡数和病死率分别排在第2位~6位和第4位~8位,在我国局部地区时有暴发,依旧是严重威胁儿童健康的主要传染病之一.本文在对我国乙脑防治工作现况、存在的问题进行分析的基础上,提出了相应的防制策略.…… 相似文献
36.
37.
A theoretical one-compartment pharmacokinetic model is described, the aim of which is to guide factor VIII replacement therapy in patients with haemophilia A suffering from significant and ongoing haemorrhage. Based on our calculations, plasma factor VIII concentrations can decrease at a rapid rate even with non-severe blood loss. 相似文献
38.
K.K. Roy Jinee Baruah Sunesh Kumar A.K. Deorari J.B. Sharma Debjyoti Karmakar 《Indian journal of pediatrics》2008,75(12):1249-1252
Objective To find out the efficacy of continuous fetal heart monitoring by analyzing the cases of cesarean section for nonreassuring
fetal heart in labor, detected by cardiotocography (CTG) and correlating these cases with perinatal outcome. To evaluate whether
a 30 minute decision to delivery (D-D) interval for emergency cesarean section influences perinatal outcome.
Methods This was a prospective observational study of 217 patients who underwent cesarean section at ≥ 36 weeks for non-reassuring
fetal heart in labor detected by CTG. The maternal demographic profile, specific types of abnormal fetal heart rate tracing
and the decision to delivery time interval were noted. The adverse immediate neonatal outcomes in terms of Apgar score <7
at 5 minutes, umbilical cord tH <7.10, neonates requiring immediate ventilation and NICU admissions were recorded. The correlation
between non-reassuring fetal heart, decision to delivery interval and neonatal outcome were analyzed.
Results Out of 3148 patients delivered at ≥ 36 weeks, 217 (6.8%) patients underwent cesarean section during labor primarily for non-reassuring
fetal heart. The most common fetal heart abnormality was persistent bradycardia in 106 (48.8%) cases followed by late deceleration
in 38 (17.5%) cases and decreased beat to beat variability in 17 (7.8%) cases. In 33 (15.2%) babies the 5 minutes Apgar score
was <7 out of which 13 (5.9%) babies had cord tH <7.10. Thirty three (15.2%) babies required NICU admission for suspected
birth asphyxia. Rest 184 (84.7%) neonates were born healthy and cared for by mother. Regarding decision to delivery interval
of ≤30 minutes versus >30 minutes, there was no significant difference in the incidence of Apgar score <7 at 5 minutes, cord
pH <7.10 and new born babies requiring immediate ventilation. But the need for admission to NICU in the group of D-D interval
≤ 30 minutes was significantly higher compared to the other group where D-D interval was >30 minutes.
Conclusion Non-reassuring fetal heart rate detected by CTG did not correlate well with adverse neonatal outcome. There was no significant
difference in immediate adverse neonatal outcome whether the D-D time interval was ≤ 30 minutes or >30 minutes; contrary to
this, NICU admission for suspected birth asphyxia in ≤ 30 minutes group was significantly higher. 相似文献
39.
Vitamin D3, having gained scientific interest for so long because of its role in mineral homeostasis, has now received great importance as a possible antitumor agent. This study was undertaken in an attempt to visualize the possible anticlastogenic potential of the vitamin in an ascitic mouse lymphoma model namely, Dalton's lymphoma. Frequencies of structural type chromosomal aberrations, sister chromatid exchanges and micronucleus assays have been chosen as the genotoxic endpoints in the proposed investigation. All these cytogenetic markers have been found to be markedly elevated during the progression of lymphoma in bone marrow cells. Vitamin D3 effectively suppressed the frequencies of chromosomal aberrations and sister chromatid exchanges in the lymphoma-bearing mice during the entire phase of tumor growth that significantly coupled with almost two-fold increase in survival time (37 +/- 2 and 68 +/- 2 days in lymphoma controls and vitamin D3-treated lymphoma-bearing mice, respectively), thus substantiating the antineoplastic efficacy of this secosteroid. The outcome of this study also is clearly reflected in the depletion of circulating (serum) vitamin D3 levels in the lymphoma control mice compared with normal (vehicle) controls while a still higher level was maintained in the VD3-treated lymphoma mice. This anticlastogenic property of the vitamin has so far been neglected and this is the first attempt to unravel the vitamin D3's effect in combating tumor development in vivo by limiting the frequencies of chromosomal aberrations, sister chromatid exchanges and micronuclei at least in transplantable murine model studied herein. 相似文献
40.
Dasgupta S Karmakar PR Mandal NK Roy RP Mallik S Mandal AK 《Indian journal of public health》2005,49(4):223-226
The study was conducted at Birbhum and Purba Medinipur districts of West Bengal to assess the routine primary immunization coverage following 40 cluster sampling technique was used to study 320 children in each of the districts. BCG coverage was found to be 79.69% at Birbhum and 84.38% at Purba Medinipur. Only 62.81% children at Birbhum and 67.81% children at Purba Medinipur received all the three primary doses of DPT. Regarding OPV, coverage with three primary doses were only 65% and 66.88% at Birbhum and Purba Medinipur respectively. Measles vaccine coverage was very poor at both the districts, 55.94% at Birbhum and 62.5% at Purba Medinipur. Full primary immunization was observed 53.13% and 61.56% in Birbhum and Purba Medinipur respectively. High drop-out rate was identified as a major deficiency in both the districts. Of the children who received at least one routine vaccine, more than 1/3rd at Birbhum and more than 1/4 th at Purba Medinipur did not turn up later for completion of their primary vaccine doses. It is evident that routine immunization coverage was poor in both the districts and it seems there has been no improvement in situation for last few years. It will influence not only the child morbidity and mortality situation but also will jeopardize the paralytic polio eradication programme. Urgent intervention should be undertaken to address the large number of non-immunized children as well as high proportion of drop-outs. 相似文献