全文获取类型
收费全文 | 2511篇 |
免费 | 247篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 103篇 |
妇产科学 | 39篇 |
基础医学 | 312篇 |
口腔科学 | 174篇 |
临床医学 | 199篇 |
内科学 | 531篇 |
皮肤病学 | 47篇 |
神经病学 | 138篇 |
特种医学 | 87篇 |
外科学 | 321篇 |
综合类 | 124篇 |
一般理论 | 1篇 |
预防医学 | 169篇 |
眼科学 | 136篇 |
药学 | 138篇 |
中国医学 | 3篇 |
肿瘤学 | 238篇 |
出版年
2023年 | 29篇 |
2022年 | 20篇 |
2021年 | 71篇 |
2020年 | 58篇 |
2019年 | 79篇 |
2018年 | 90篇 |
2017年 | 71篇 |
2016年 | 80篇 |
2015年 | 76篇 |
2014年 | 90篇 |
2013年 | 100篇 |
2012年 | 172篇 |
2011年 | 140篇 |
2010年 | 84篇 |
2009年 | 69篇 |
2008年 | 94篇 |
2007年 | 118篇 |
2006年 | 88篇 |
2005年 | 96篇 |
2004年 | 128篇 |
2003年 | 72篇 |
2002年 | 88篇 |
2001年 | 76篇 |
2000年 | 75篇 |
1999年 | 66篇 |
1998年 | 34篇 |
1997年 | 21篇 |
1996年 | 23篇 |
1995年 | 17篇 |
1994年 | 29篇 |
1993年 | 18篇 |
1992年 | 33篇 |
1991年 | 37篇 |
1990年 | 57篇 |
1989年 | 38篇 |
1988年 | 36篇 |
1987年 | 40篇 |
1986年 | 34篇 |
1985年 | 32篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 14篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 33篇 |
1977年 | 16篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1972年 | 11篇 |
1971年 | 9篇 |
排序方式: 共有2770条查询结果,搜索用时 15 毫秒
51.
Endoscopic sphincterotomy for removal of stones from the common bile duct, in particular in high-risk patients is an established procedure. However, the size of the stones and the appearance of the terminal bile duct prior to sphincterotomy have an influence on the outcome. In the period 1984-1987, thirty-four patients considered to be at high risk for surgery were treated endoscopically by insertion of a biliary endoprosthesis (15 cm long, 3.2 mm diameter) after unsuccessful attempts to remove common bile duct (CBD) stones following endoscopic sphincterotomy. These patients were admitted to the hospital with biliary colic, obstructive jaundice and/or cholangitis. Eight patients were lost to follow-up. The remaining patients comprised 20 females and 6 males, with a mean age of 81 years (range: 60-96). Five patients underwent surgical treatment for perforation (one patient, 11 months after insertion), persistent jaundice (one patient) or recurrent obstructive jaundice (endoprosthesis clogging in one, endoprosthesis dislodgement in two patients) 2 to 40 months after insertion. In one patient, recurrent obstructive jaundice was successfully treated by replacing the clogged endoprosthesis 4 months after the initial treatment. Ten patients died of unrelated causes (myocardial infarction, accident, etc.) 2 to 28 months after insertion. The remaining ten patients were still alive without symptoms after a median follow-up of 26 months. On the basis of these findings we therefore conclude that endoscopic insertion of a biliary endoprosthesis is a safe and effective treatment for huge CBD stones in high-risk patients in whom endoscopic sphincterotomy and attempts to remove the stones are not successful. 相似文献
52.
Role of viral infectivity in the induction of influenza virus-specific cytotoxic T cells 总被引:8,自引:1,他引:8 下载免费PDF全文
This report examines the requirement for infectious virus in the induction of influenza virus-specific cytotoxic T cells. Infectious influenza virus was found to be highly efficient at generating both primary and secondary cytotoxic T-cell response in vivo. Inactivated influenza virus however, failed to stimulate a detectable cytotoxic T-cell response in vivo even at immunizing doses 10(5)-10(6)-fold higher than the minimum stimulatory dose of infectious virus. Likewise inactivated virus failed to sensitize target cells for T cell-mediated lysis in vitro but could stimulate a specific cytotoxic response from primed cells in vitro. Possible requirements for the induction of virus-specific cytotoxic T-cell responses are discussed in light of these observations and those of other investigators. 相似文献
53.
We assessed the pharmacokinetics of three different doses of indinavir in five patients. All doses achieved trough concentrations above efficacy thresholds. Toxic trough concentrations were observed in all patients receiving 800 mg, in two patients receiving 600 mg, and in none receiving 400 mg. Indinavir at 400 mg may be efficacious and less toxic in patients taking ritonavir and efavirenz. 相似文献
54.
Thuraisingham S Tan KH Chong KS Yap SF Pasamanikam K 《International journal of clinical practice》2000,54(2):78-84
There is little evidence to show that strict dietary modification alone confers any significant impact on cardiac events in primary and secondary prevention of coronary heart disease. Given the efficacy of the statins, the need for strict dietary modification in patients on statin therapy has been questioned. This study was performed to assess 1) the added benefit on serum lipid levels of a strict low-fat dietary regimen in patients with hypercholesterolaemia already treated with simvastatin; 2) the efficacy of simvastatin on the lipid profile of our sample Asian population; and 3) the tolerability and side-effect profile of simvastatin. This study was a prospective evaluation of 60 patients with hypercholesterolaemia treated with simvastatin who were subjected to either a normal diet or a dietitian guided low-fat diet. Assessment of the effects on serum lipid levels, side-effects, biochemical and haematological markers were performed. After 24 weeks of treatment, a strict dietitian guided low-fat diet conferred no additional benefit over and above what was achieved by simvastatin alone. Furthermore, a higher dose of simvastatin was needed in the dietitian guided diet group to achieve the target LDL-cholesterol level. Simvastatin resulted in a significant positive alteration of lipid profiles in all patients. The drug was well tolerated, with no significant change in either haematological or biochemical indices. Simvastatin is a highly effective cholesterol-lowering drug with a beneficial effect on the entire lipid spectrum in a cross-section of Asian patients, and is well tolerated. A dietitian guided dietary approach confers no additional advantage once statin therapy has been initiated. 相似文献
55.
Leslie Lim Hong Ngee Chan Peng Hoe Chew Sze Ming Chua Carolyn Ho Seow Khee Daniel Kwek Tih Shih Lee Patricia Loh Alvin Lum Yong Hui Colin Tan Yi Min Wan Matthew Woo Hwa Ling Yap 《Singapore medical journal》2015,56(6):310-316
The Ministry of Health (MOH) has developed the clinical practice guidelines on Anxiety Disorders to provide doctors and patients in Singapore with evidence-based treatment for anxiety disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on anxiety disorders, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.
1.1 Background information
Anxiety disorders are known to be one of the most prevalent of psychiatric conditions, yet they often remain under-diagnosed and under-treated. Their chronic, disabling symptoms cause considerable burden not only to sufferers but also to their families, and contribute to poorer quality of life and considerable economic burden on society.In many instances, there is a delay in seeking treatment and in some cases such delay may stretch up to nearly ten years. This may result from ignorance of the condition, fear of taking medications, and the stigma of receiving a psychiatric diagnosis, and or having to accept psychiatric treatment.The anxiety disorders include panic disorder with or without agoraphobia, social anxiety disorder, specific phobia, obsessive-compulsive disorder, generalised anxiety disorder, acute stress disorder and post-traumatic stress disorder. In the clinical evaluation of anxiety disorders, it is important to ascertain the type of anxiety disorder present. This would allow treatment to be targeted at the specific type of disorder.These guidelines are developed to provide practical, evidence-based recommendations to primary care physicians and specialists in psychiatry for the diagnosis and management of the anxiety disorders.The first edition of the guidelines was published in 2003. In this edition, we present data from newer research as well as older data not previously reported in the earlier guidelines.For example, we examine the efficacy of combining medications with psychological therapy over medications alone, or psychological therapy alone. In view of the majority of anxiety sufferers being female we have made recommendations for pharmacotherapy during pregnancy and breastfeeding. As these guidelines are intended for use in the Singapore context, we have omitted treatments that are currently not available in Singapore.1.2 Aim
These guidelines are developed to facilitate the diagnosis and assessment of the anxiety disorders, and to ensure that their management is appropriate and effective.1.3 Scope
These guidelines will cover the management of anxiety disorders in adults and address the issues of medication use during pregnancy and breastfeeding.1.4 Target group
The content of the guidelines will be useful for all doctors treating patients with anxiety disorders. Efforts have been made to ensure that the guidelines are particularly useful for primary care physicians and specialists in psychiatry, including all those involved in the assessment and management of patients with anxiety disorders in the community. The doctor treating the patient is ultimately responsible for clinical decisions made after reviewing the individual patient’s history, clinical presentation and treatment options available.1.5 Development of guidelines
These guidelines have been produced by a committee of psychiatrists, a clinical psychologist, pharmacist, patient representative, and family practitioners appointed by the Ministry of Health. They were developed by revising the existing guidelines, reviewing relevant literature, including overseas clinical practice guidelines, and by expert clinical consensus of professionals with experience in treating patients in the local setting.The following principles underlie the development of these guidelines:- Treatment recommendations are supported by scientific evidence whenever possible (randomised controlled clinical trials represent the highest level of evidence) and expert clinical consensus is used when such data are lacking.
- Treatment should maximise therapeutic benefits and minimise side effects.
1.6 What’s new in the revised guidelines
This edition of the guidelines contains updated recommendations based on latest evidence, as well as detailed discussions and recommendations on the management of anxiety disorders in adult populations.The following represent changes to the revised guidelines- An extensive review of the literature, including new evidence. This involved the re-writing and extensive revision of the chapters.
- Length of treatment, which provides answers to a pertinent question.
- Use of medications during pregnancy and breastfeeding. Given that females are more likely to be at risk of being diagnosed with anxiety disorders, this is an important subject.
1.7 Review of guidelines
Evidence-based clinical practice guidelines are only as current as the evidence that supports them. Users must keep in mind that new evidence could supersede recommendations in these guidelines. The workgroup advises that these guidelines be scheduled for review five years after publication, or when new evidence appears that requires substantive changes to the present recommendations. 相似文献56.
Swati Handa Audrey Chia Hla Myint Htoon Pin Min Lam Fabian Yap Yvonne Ling 《Singapore medical journal》2015,56(8):450-454
INTRODUCTION
This study aimed to evaluate the proportion of young patients with type 1 diabetes mellitus (T1DM) who have myopia, as well as the risk factors associated with myopia in this group.METHODS
In this cross-sectional study, patients aged < 21 years with T1DM for ≥ 1 year underwent a comprehensive eye examination. Presence of parental myopia, and average hours of near-work and outdoor activity were estimated using a questionnaire. Annualised glycosylated haemoglobin (HbA1c), defined as the mean of the last three HbA1c readings taken over the last year, was calculated. Multivariate analysis using genetic, environmental and diabetes-related factors was done to evaluate risk factors associated with myopia.RESULTS
Of the 146 patients (mean age 12.5 ± 3.6 years) recruited, 66.4% were Chinese and 57.5% were female. Myopia (i.e. spherical equivalent [SE] of –0.50 D or worse) was present in 96 (65.8%) patients. The proportion of patients with myopia increased from 25.0% and 53.6% in those aged < 7.0 years and 7.0–9.9 years, respectively, to 59.2% and 78.4% in those aged 10.0–11.9 years and ≥ 12.0 years, respectively. Higher levels of SE were associated with lower parental myopia (p = 0.024) and higher annualised HbA1c (p = 0.011).CONCLUSION
Compared to the background population, the proportion of myopia in young patients with T1DM was higher in those aged < 10 years but similar in the older age group. Myopia was associated with a history of parental myopia. Environmental risk factors and poor glycaemic control were not related to higher myopia risk. 相似文献57.
The Effect of a Polyvalent Antivenom on the Serum Venom Antigen Levels of Naja sputatrix (Javan Spitting Cobra) Venom in Experimentally Envenomed Rabbits 下载免费PDF全文
Michelle Khai Khun Yap Nget Hong Tan Si Mui Sim Shin Yee Fung Choo Hock Tan 《Basic & clinical pharmacology & toxicology》2015,117(4):274-279
The treatment protocol of antivenom in snake envenomation remains largely empirical, partly due to the insufficient knowledge of the pharmacokinetics of snake venoms and the effects of antivenoms on the blood venom levels in victims. In this study, we investigated the effect of a polyvalent antivenom on the serum venom antigen levels of Naja sputatrix (Javan spitting cobra) venom in experimentally envenomed rabbits. Intravenous infusion of 4 ml of Neuro Polyvalent Snake Antivenom [NPAV, F(ab′)2] at 1 hr after envenomation caused a sharp decline of the serum venom antigen levels, followed by transient resurgence an hour later. The venom antigen resurgence was unlikely to be due to the mismatch of pharmacokinetics between the F(ab′)2 and venom antigens, as the terminal half‐life and volume of distribution of the F(ab′)2 in serum were comparable to that of venom antigens (p > 0.05). Infusion of an additional 2 ml of NPAV was able to prevent resurgence of the serum venom antigen level, resulting in a substantial decrease (67.1%) of the total amount of circulating venom antigens over time course of envenomation. Our results showed that the neutralization potency of NPAV determined by neutralization assay in mice may not be an adequate indicator of its capability to modulate venom kinetics in relation to its in vivo efficacy to neutralize venom toxicity. The findings also support the recommendation of giving high initial dose of NPAV in cobra envenomation, with repeated doses as clinically indicated in the presence of rebound antigenemia and symptom recurrence. 相似文献
58.
59.
60.