全文获取类型
收费全文 | 3756篇 |
免费 | 179篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 190篇 |
妇产科学 | 38篇 |
基础医学 | 350篇 |
口腔科学 | 69篇 |
临床医学 | 278篇 |
内科学 | 914篇 |
皮肤病学 | 87篇 |
神经病学 | 228篇 |
特种医学 | 139篇 |
外科学 | 629篇 |
综合类 | 48篇 |
一般理论 | 3篇 |
预防医学 | 150篇 |
眼科学 | 190篇 |
药学 | 212篇 |
中国医学 | 4篇 |
肿瘤学 | 375篇 |
出版年
2023年 | 26篇 |
2022年 | 39篇 |
2021年 | 140篇 |
2020年 | 64篇 |
2019年 | 96篇 |
2018年 | 102篇 |
2017年 | 80篇 |
2016年 | 90篇 |
2015年 | 120篇 |
2014年 | 152篇 |
2013年 | 190篇 |
2012年 | 276篇 |
2011年 | 289篇 |
2010年 | 192篇 |
2009年 | 134篇 |
2008年 | 243篇 |
2007年 | 254篇 |
2006年 | 252篇 |
2005年 | 241篇 |
2004年 | 217篇 |
2003年 | 169篇 |
2002年 | 163篇 |
2001年 | 43篇 |
2000年 | 35篇 |
1999年 | 33篇 |
1998年 | 38篇 |
1997年 | 27篇 |
1996年 | 24篇 |
1995年 | 20篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 11篇 |
1989年 | 18篇 |
1988年 | 21篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有3947条查询结果,搜索用时 15 毫秒
1.
2.
Neetu Radhakrishnan M.D. Chong. H. Park M.D. Barry M. Kaplan M.D. F.A.C.C. Rajiv Jauhar M.D. F.A.C.C. 《The International journal of angiology》2006,15(1):37-42
A 65-year-old man developed acute limb ischemia, severe abdominal wall and lower limb livedo reticularis following a coronary
angiogram. The differential diagnoses of acute limb ischemia and multiple cholesterol emboli syndrome (MCES) are discussed.
This work was performed at Long Island Jewish Medical Center, 270-05, 76th Avenue, New Hyde Park, NY 11040. 相似文献
3.
The clinical relevance of t(14; 18)/BCL-2 rearrangement and DEL 6q in diffuse large cell lymphoma and immunoblastic lymphoma 总被引:1,自引:0,他引:1
Background: t(14; 18)/bcl-2 gene rearrangement (R) is claimedto impart a worse rate of complete remission and disease-freesurvival in diffuse large cell lymphoma (DLCL). DEL 6q has alsobeen associated with poor outcome. Design: Retrospective studyof 54 patients with either diffuse large cell or immunoblasticlymphoma who had cytogenetics and/or molecular studies performed.Results: Patient characteristics, complete remission rate, andtime to treatment failure (TTF) were similar at three year follow-upfor groups with and without t(14; 18)/BCL-2R Survival was worsefor the former but the difference was not statistically significant.For DEL 6q, patient characteristics and survival rates weresimilar at three year follow-up for patients with and withoutthe abnormality. TTF was worse for the former but this was notstatistically significant. Conclusion: This study, with equalor greater number of patients with t(14; 18) than previous reports,fails to show a worse prognosis for patients with the t(14;18) chromosomal abnormality. A definite association will awaitfurther accrual of patients and a meaningul multivariate analysis. lymphoma, BCL-2, cytogenetics, DEL 6q 相似文献
4.
We report our experience of eight cases of isolated full thickness burns of the penis. Early excision of burns of the penile shaft and repair with a preputial flap or mesh split skin graft produces excellent results, with a reduction in complications and an early re-establishment of sexual function. Conservative treatment of burns of the glans, on the other hand, is appropriate and results in minimal scarring. 相似文献
5.
Measurement of cerebral monoamine oxidase B activity using L-[11C]deprenyl and dynamic positron emission tomography 总被引:3,自引:0,他引:3
A A Lammertsma C J Bench G W Price J E Cremer S K Luthra D Turton N D Wood R S Frackowiak 《Journal of cerebral blood flow and metabolism》1991,11(4):545-556
A tracer kinetic procedure was developed for the measurement of monoamine oxidase type B (MAO-B) activity using L-[11C]deprenyl and positron emission tomography (PET). The kinetic model consisted of two tissue compartments with irreversible binding to the second compartment (three rate constants). In addition, a blood volume component was included. Special attention was given to the accurate measurement of the plasma and whole blood input functions. The method was applied to the measurement of the dose-response curve of a reversible MAO-B inhibitor (Ro 19-6327). From the results, it followed that the rate constant for irreversible binding (k3) appeared to be a better index of MAO-B activity than the net influx constant Ki. Furthermore, regional analysis demonstrated that Ki, but not k3, was flow dependent. This implies that full kinetic analysis is required for an accurate assessment of MAO-B activity. 相似文献
6.
D J Brooks J S Gibbs P Sharp S Herold D R Turton S K Luthra E M Kohner S R Bloom T Jones 《Journal of cerebral blood flow and metabolism》1986,6(2):240-244
Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB. 相似文献
7.
8.
Ashok Verma Mazin Al Khabori Rajiv Zutshi 《Indian journal of otolaryngology and head and neck surgery》2006,58(1):9-14
This is a prospective, non-randomized study to evaluate and compare the results, morbidity and surgical time for endonasal carbon-dioxide laser assisted dacryocystorhinostomy and external dacryocystorhinostomy. 70 consecutive patients of chronic dacryocystitis with nasolacrimal duct obstruction were selected for the study. 36 patients under went endonasal CO2 laser assisted dacryocystorhinostomy and 34 had external dacryocystorhinostomy. Selection of the type of operation was left to the patient's choice. All the patients had preoperative counseling and both the procedures were explained in detail with their advantages and disadvantages. Patients not willing for the external incision were selected for endonasal laser assisted dacryocystorhinostomy and others were operated via external approach. Silicone tubes were put in all the patients for three months after surgery. The final follow up was 12 months after the removal of silicone tubes. The patency of the lacrimal passage was confirmed by irrigation, and patients were questioned about their symptoms. The success rates, 12 months after removal of silicone tubes were 100% in endonasal CO2 laser assisted dacryocystorhinostomy and 88.24% in external dacryocystorhinostomy. The surgical time of endonasal laser assisted dacryocystorhinostomy was 38 minutes as compared to 62 in external dacryocystorhinostomy. Complication rate in both groups was almost equal. Thus, we came to the conclusion that Endonasal CO2 laser assisted dacryocystorhinostomy is a better surgical option to external dacryocystorhinostomy in cases of chronic dacryocystitis with nasolacrimal duct obstruction, with shorter surgical time. 相似文献
9.
Measuring the efficacy of antiepileptic drugs. 总被引:4,自引:0,他引:4
Clinical trials of new antiepileptic drugs (AEDs) include regulatory studies aimed at demonstrating efficacy and reasonable safety, post-marketing open-open label studies and longer term outcome studies. Regulatory trials involve a carefully selected population of patients and are conducted under rigorously standardised conditions. Data from such studies cannot often be translated into clinical practice. Pragmatic post-marketing studies using flexible dosing schedules allow clinicians to better judge the utility of the new drug in a wider population of patients with epilepsy and decide the most appropriate dosing schedules. This paper discusses some of the issues surrounding the measurement of efficacy of new AEDs in both pre- and post-marketing phases of their development. All of the newer AEDs are initially used in patients with refractory partial seizures as adjunctive treatment. These trials are generally parallel-group studies although cross-over designs have been employed. The use of placebo-control is uncontroversial in this type of study. Efficacy endpoints are generally manipulations of seizure frequency on study drug compared to control. Global outcome measures and health related quality of life scores can also be used to measure efficacy. As the standard AEDs are associated with a high rate of seizure remission in patients who receive them as monotherapy, demonstration of superior efficacy of a new agent in a comparative trial will require large numbers of patients in a design that takes into account the natural history of treated epilepsy. Comparing investigational agents to a standard AED in an 'active-control' study with demonstration of equivalent efficacy would seem to be an acceptable way of assessing efficacy of new AEDs in this population. Some regulators, however, do not accept equivalence as proof of efficacy and insist on demonstration of superiority compared to a control. The use of placebo alone in the control group is ethically dubious. Several innovative study designs have, therefore, been used to satisfy regulatory requirements, while maintaining patient safety including withdrawal to monotherapy using high versus low dose comparators. Observational outcome studies provide the best opportunity of exploring the long-term utility of individual AEDs. Such studies largely follow standard clinical practice and need considerable time and resources. They can, however, yield valuable information about the effectiveness of AEDs in everyday clinical practice. Data from regulatory trials should be complemented by postmarketing studies and longer term studies of outcome to help clinicians decide the best way of utilising new AEDs and establishing their role in the therapeutic armamentarium. 相似文献
10.
Hazards of smoking 总被引:1,自引:0,他引:1
A strong association exists between cigarette smoking and several diseases namely, cancer of the lung, bronchitis and emphysema, cancer of the larynx, oral cavity and oesophagus, gastric and duodenal ulcers, Crohn's disease, cancer of the bladder, coronary artery disease, macrocytosis, polycythaemia, leukaemia, etc. This is due to the harmful constituents of cigarette and other modalities smoking. Smokers not only harm themselves but also harm those around. Foetal malformations, abortions, stillbirths, prematurity and low birth weight are common in smoker mothers. These are the effects of passive smoking. There is no safer cigarette in the market even by lowering its harmful constituents. Mass education about the hazards of smoking with emphasis on complete stoppage of smoking is the only way to prevent its rising incidence. 相似文献