全文获取类型
收费全文 | 3004篇 |
免费 | 199篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 143篇 |
妇产科学 | 38篇 |
基础医学 | 695篇 |
口腔科学 | 70篇 |
临床医学 | 227篇 |
内科学 | 365篇 |
皮肤病学 | 58篇 |
神经病学 | 245篇 |
特种医学 | 141篇 |
外科学 | 342篇 |
综合类 | 312篇 |
一般理论 | 3篇 |
预防医学 | 213篇 |
眼科学 | 30篇 |
药学 | 102篇 |
1篇 | |
中国医学 | 10篇 |
肿瘤学 | 205篇 |
出版年
2022年 | 24篇 |
2021年 | 35篇 |
2020年 | 33篇 |
2019年 | 46篇 |
2018年 | 52篇 |
2017年 | 34篇 |
2016年 | 38篇 |
2015年 | 64篇 |
2014年 | 75篇 |
2013年 | 97篇 |
2012年 | 148篇 |
2011年 | 156篇 |
2010年 | 122篇 |
2009年 | 98篇 |
2008年 | 174篇 |
2007年 | 134篇 |
2006年 | 149篇 |
2005年 | 127篇 |
2004年 | 128篇 |
2003年 | 91篇 |
2002年 | 105篇 |
2001年 | 118篇 |
2000年 | 105篇 |
1999年 | 82篇 |
1998年 | 55篇 |
1997年 | 58篇 |
1996年 | 52篇 |
1995年 | 31篇 |
1994年 | 37篇 |
1993年 | 25篇 |
1992年 | 63篇 |
1991年 | 44篇 |
1990年 | 40篇 |
1989年 | 44篇 |
1988年 | 39篇 |
1987年 | 31篇 |
1986年 | 36篇 |
1985年 | 30篇 |
1984年 | 27篇 |
1983年 | 19篇 |
1982年 | 14篇 |
1980年 | 15篇 |
1979年 | 26篇 |
1978年 | 24篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1975年 | 14篇 |
1972年 | 22篇 |
1971年 | 15篇 |
1970年 | 20篇 |
排序方式: 共有3209条查询结果,搜索用时 15 毫秒
41.
Shreffler WG Lencer DA Bardina L Sampson HA 《The Journal of allergy and clinical immunology》2005,116(4):893-899
BACKGROUND: Detailed assessment of antibody responses to allergens reveals clinically relevant information about both host response and antigen structure. Microarray technology offers advantages of scale and parallel design over previous methods of epitope mapping. OBJECTIVE: We designed a redundant peptide microarray for IgE and IgG4 epitope mapping of the previously characterized peanut allergen, Ara h 2. METHODS: Six complete sets of overlapping peptides were commercially synthesized and site-specifically bound to epoxy-derivatized glass slides in triplicate. Peptides were 10, 15, or 20 amino acids in length with an offset of either 2 or 3 amino acids. A total of 10 control and 45 peanut-allergic sera were assayed. Specific IgE and IgG4 were detected by using fluorochrome-labeled monoclonal secondary antibodies. RESULTS: By using 15-mer and 20-mer peptides, we could define 11 antigenic regions, whereas only 5 were identifiable using 10-mers. Controls and patients produced IgG4 recognizing a comparable number of Ara h 2 peptides, although the dominant epitopes were distinct. As expected, patient IgE bound a larger number of Ara h 2 peptides (9.4% vs 0.9%). IgE and IgG4 epitopes recognized by patients were largely the same, and there was a positive association between IgE and IgG(4) signal, suggesting coordinate regulation. Cluster analysis of peptide binding patterns confirmed the specificity of antibody-peptide interactions and was used to define 9 core epitopes ranging from 6 to 16 residues in length-7 of which (78%) agreed with previous mapping. CONCLUSION: Epitope mapping by microarray peptide immunoassay and cluster analysis reveals interpatient heterogeneity and a more detailed map. 相似文献
42.
43.
44.
45.
Aneurysm of sinus of Valsalva dissecting into interventricular septum is a rare entity. We report one such case who was incidentally diagnosed by echocardiography to have this abnormality during evaluation of a clinically suspected isolated aortic regurgitation.KEY WORDS: Aneurysm – dissecting – sinus of Valsalva, Echocardiography 相似文献
46.
Multivariate random length data occur when we observe multiple measurements of a quantitative variable and the variable number of these measurements is also an observed outcome for each experimental unit. For example, for a patient with coronary artery disease, we may observe a number of lesions in that patient's coronary arteries, along with percentage of blockage of each lesion. Barnhart and Sampson first proposed the multiple population model to analyse multivariate random length data without covariates. This paper extends their approach to deal with multiple covariates. We propose a new multiple population regression model with covariates, and discuss the estimation issues. We analyse data from the TYPE II coronary intervention study to illustrate the methodology. 相似文献
47.
Barr DB Barr JR Driskell WJ Hill RH Ashley DL Needham LL Head SL Sampson EJ 《Toxicology and industrial health》1999,15(1-2):168-179
Pesticides are used on a massive scale in the United States. The widespread use of these pesticides has made it virtually impossible for the average person to avoid exposure at some level. Generally, it is believed that low-level exposure to these pesticides does not produce acute toxic effects; however, various cancers and other noncancer health endpoints have been associated with chronic exposure to several groups of pesticides. Therefore, it is imperative that well-designed studies investigate the potential relationship between contemporary pesticide exposure and health effects. For these studies to be accurate, reliable methods for determining individual exposure must be used. Biological monitoring is a useful tool for assessing exposure to some contemporary pesticides. As with any analytical method, biological monitoring entails many difficulties, but, in many instances, they can be overcome by the logical use of available information and information acquired in carefully designed studies. At the Centers for Disease Control and Prevention (CDC), we have acquired extensive experience in the development and application of specific techniques for biological monitoring of a variety of toxicants, including many of the contemporary-use pesticides. We have used these methods to measure the internal dose of pesticides received by people in acute and chronic incidents resulting from both environmental and industrial exposure. Additionally, we have established normative values, or reference ranges, of several pesticides based on measurements of their metabolites in the urine of randomly selected adults in the US population. These data have been successfully used to distinguish overt exposures from 'background' exposure. In this paper, we present several examples of the usefulness of biological monitoring in urine and blood and describe the difficulties involved with developing methods in these matrices. We also present a general strategy, considerations, and recommendations for developing biological monitoring techniques for measuring the internal dose of contemporary-use pesticides. 相似文献
48.
49.
E M Sadeghi L L Weldon P H Kwon E Sampson 《International journal of oral and maxillofacial surgery》1991,20(3):142-143
This unusual cystic lesion was previously described as a lesion that has features of both botryoid odontogenic cyst and mucoepidermoid tumor and later was named as glandular odontogenic cyst. An additional case is reported and its clinicopathologic features described. The name "mucoepidermoid odontogenic cyst" is proposed. 相似文献
50.
Prithi Pal Singh Ivan Dimich Ian Sampson Norman Sonnenklar 《Journal canadien d'anesthésie》1992,39(6):559-562
This is an open randomized study comparing the efficacy and safety of i.v. esmolol and labetalol in the treatment of perioperative hypertension in ambulatory surgery. Twenty-two elderly patients undergoing cataract surgery under local anaesthesia were studied. The main inclusion criteria were development of systolic blood pressure greater than 200 mmHg or diastolic greater than 100 mmHg. Esmolol was given as a bolus 500 micrograms.kg-1 i.v. followed by a maintenance infusion (150-300 micrograms.kg-1.min-1). Labetalol was given as a bolus of 5 mg i.v. followed by 5 mg increments as needed up to a maximum of 1 mg.kg-1. Esmolol and labetalol both produced reductions in systolic and diastolic blood pressure (P less than 0.05) within ten minutes of administration which lasted for at least two hours. Reduction of blood pressure by esmolol was accompanied by a decrease in HR (P less than 0.05). Two patients developed extreme bradycardia (HR less than 50 beats.min-1) and esmolol had to be discontinued. Labetalol, in contrast, induced only a moderate decrease in HR. None of the patients treated with labetalol experienced any prolonged side effects such as orthostatic hypotension. In conclusion, esmolol may produce considerable bradycardia in elderly patients when hypertension is not accompanied by tachycardia. Labetalol was easier to administer in the ambulatory setting and one-tenth the cost of esmolol. 相似文献