全文获取类型
收费全文 | 2931篇 |
免费 | 232篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 106篇 |
妇产科学 | 35篇 |
基础医学 | 380篇 |
口腔科学 | 58篇 |
临床医学 | 362篇 |
内科学 | 461篇 |
皮肤病学 | 11篇 |
神经病学 | 239篇 |
特种医学 | 281篇 |
外科学 | 484篇 |
综合类 | 75篇 |
一般理论 | 1篇 |
预防医学 | 153篇 |
眼科学 | 40篇 |
药学 | 324篇 |
肿瘤学 | 176篇 |
出版年
2021年 | 37篇 |
2019年 | 38篇 |
2018年 | 53篇 |
2017年 | 26篇 |
2016年 | 28篇 |
2015年 | 46篇 |
2014年 | 50篇 |
2013年 | 85篇 |
2012年 | 133篇 |
2011年 | 126篇 |
2010年 | 108篇 |
2009年 | 120篇 |
2008年 | 126篇 |
2007年 | 143篇 |
2006年 | 124篇 |
2005年 | 106篇 |
2004年 | 94篇 |
2003年 | 93篇 |
2002年 | 106篇 |
2001年 | 73篇 |
2000年 | 76篇 |
1999年 | 63篇 |
1998年 | 72篇 |
1997年 | 67篇 |
1996年 | 69篇 |
1995年 | 58篇 |
1994年 | 57篇 |
1993年 | 40篇 |
1992年 | 41篇 |
1991年 | 62篇 |
1990年 | 61篇 |
1989年 | 65篇 |
1988年 | 51篇 |
1987年 | 47篇 |
1986年 | 52篇 |
1985年 | 57篇 |
1984年 | 41篇 |
1983年 | 32篇 |
1982年 | 36篇 |
1981年 | 18篇 |
1980年 | 30篇 |
1979年 | 41篇 |
1978年 | 30篇 |
1977年 | 30篇 |
1976年 | 24篇 |
1975年 | 25篇 |
1974年 | 28篇 |
1973年 | 22篇 |
1971年 | 19篇 |
1970年 | 21篇 |
排序方式: 共有3199条查询结果,搜索用时 31 毫秒
41.
C. H. Kirkpatrick R. R. Rich R. G. Graw T. K. Smith Irad Mickenberg G. N. Rogentine 《Clinical and experimental immunology》1971,9(6):733-748
The immunological defect in a patient with chronic mucocutaneous moniliasis was characterized. While his Candida skin test was negative. exposure of his lymphocytes to candida extracts in vitro produced an increase in thymidine incorporation. Supernatants from cultures of antigen-stimulated lymphocytes did not contain macrophage migration-inhibition factor (MIF) activity.
Restoration of the immune system with transfusions of immuno-competent allogeneic lymphocytes was accompanied by conversion of the Candida skin test to positive, and MIF production by his lymphocytes. During the period that his immune system remained intact, there was marked clearing of the moniliasis. Eight months following the transfusions, the moniliasis recurred and when restudied, the patient again had negative skin tests and insignificant MIF production.
These observations demonstrate the importance of mediators in the expression of delayed hypersensitivity and provide evidence of a role of cellular immunity in resistance to certain chronic fungal infections.
相似文献42.
A J d''''Ardenne P Kirkpatrick C A Wells J D Davies 《Journal of clinical pathology》1986,39(2):138-144
The distribution of fibronectin and laminin was examined by immunohistochemistry in 11 adenoid cystic breast carcinomas, six adenoid cystic carcinomas of mouth and salivary gland, and six cribriform ductal breast carcinomas. Both proteins were present lining cystic lumina and around tumour islands in all the adenoid cystic breast carcinomas and in five of six salivary gland tumours. Abundant laminin and fibronectin were dispersed among adenoid cystic tumour cells arranged in sheets. One adenoid cystic carcinoma from buccal mucosa showed a transition from a cribriform tumour positive for both fibronectin and laminin to a cribriform tumour negative for fibronectin and laminin to undifferentiated carcinoma. Fibronectin and laminin seemed to disappear simultaneously from tumour cell surfaces. Another adenoid cystic carcinoma from buccal mucosa was negative for fibronectin and laminin from the time of initial biopsy. This was the only tumour that gave rise to disseminated metastases, resulting in the death of the patient within two years of surgery. In cribriform invasive ductal breast carcinomas the linings of cystic lumina were always negative for fibronectin and laminin. Varying quantities were present at the tumour boundaries. We suggest that staining for fibronectin and laminin may be a valuable aid to the diagnosis of adenoid cystic carcinomas and that the absence of these proteins may have important prognostic implications. 相似文献
43.
Kirkpatrick SE; Pitlick PT; Naliboff J; Friedman WF 《The American journal of physiology》1976,231(2):495-500
44.
45.
46.
47.
The aim of the study was to conduct a structured review of theliterature published on the use of normal sperm morphology,as an indicator of male fertility potential in the in-vitrofertilization (IVF) situation, and to establish the universalpredictive value of this semen parameter. Published literaturein which normal sperm morphology was used to predict fertilizationand pregnancy, during the period 1978-1996, was reviewed. Atotal of 216 articles were identified by the sourcing methodology,but only 49 provided data that could be tabulated and analysed.Of these, only 18 provided sufficient data for statistical analysis.Fifteen studies used the strict criteria to evaluate sperm morphology,two used World Health Organization (WHO) guidelines and oneused both the strict criteria and the WHO guidelines. All thestudies (n=10) using the 5 and 14% normal sperm morphology thresholds(strict criteria) produced positive predictive values for IVFsuccess. In the prediction of pregnancy, 82% (9/11) and 75%(6/8) of the studies produced positive predictive values whenusing the 5% and 14% thresholds respectively. Aggregating thedata produced around the 5% normal sperm morphology threshold(strict criteria), the overall fertilization rates were 59.3%(1979/3337; per oocyte) for the 4% group and 77.6% (10345/13327;per oocyte) for the >4% group, and the overall pregnancyrates were 15.2% (60/395; per cycle) and 26.0% (355/1368; percycle) respectively. The no-transfer rates across the 5% thresholdwere 24.0% (86/359; per cycle) in the 4% group compared to 7.4%(80/1088; per cycle) in the >4% group. The inclusion of anaccurately evaluated normal sperm morphology count as an integralpart of the standard semen analysis makes this analysis stillthe most cost-effective means of evaluating the male factor. 相似文献
48.
Müller AM Hermanns MI Skrzynski C Nesslinger M Müller KM Kirkpatrick CJ 《Experimental and molecular pathology》2002,72(3):221-229
EC culture models are essential to study pathological alterations of endothelial cells (ECs) in pulmonary vascular diseases under standardized conditions. Nevertheless, little is known about the spectrum of alterations of vessel-specific endothelial phenotypes in monolayer cultures. For the comparative study of endothelial markers in vivo and in vitro we investigated immunohistochemically the expression of PECAM-1, vWf, and CD34 by pulmonary ECs in vivo and in stimulated/unstimulated human umbilical vein endothelial cells (HU-VEC) and human pulmonary microvascular endothelial cells (HPMEC). In vivo, vessel type-specific expression patterns were found for vWf and CD34, while PECAM-1 was homogeneously and strongly expressed. While all HUVEC showed a marked vWf staining, about two-thirds of HPMEC exhibited a strong and the rest a moderate vWf staining. In both in vitro models all ECs were clearly PECAM-1-positive. However, only about 20% of the HUVEC and HPMEC were CD34-positive. Our results demonstrate the reduced expression of vessel type-specific endothelial phenotypes by endothelial monolayer cultures, stressing the need to improve culture conditions as well as develop cocultures and three-dimensional culture models. Moreover, the need for endothelial markers specific for single microvascular type ECs becomes obvious in order to establish cultures consisting of only one microvascular ECs subpopulation. 相似文献
49.
Ahuja K.K.; Simons E.G.; Fiamanya W.; Dalton M.; Armar N.A.; Kirkpatrick P.; Sharp S.J.; Arian-Schad M.; Seaton A.; Watters A.J. 《Human reproduction (Oxford, England)》1996,11(5):1126-1131
The present acute shortage of eggs for donation cannot be overcomeunless adequate guidelines are set to alleviate the anxietiesregarding payments, in cash or kind, to donors. The currentHuman Fertilisation and Embryology Authority (HFEA) guidelinesdo not allow direct payment to donors but accept the provisionof lower cost or free in-vitro fertilization (IVF) treatmentto women in recognition of oocyte donation to anonymous recipients.Egg-sharing achieved in this way enables two infertile couplesto benefit from a single surgical procedure. However, the practicalguidelines related to this approach are ill-defined at the presenttime leading to some justifiable uncertainty. A pilot studywas therefore undertaken in order to establish the place ofegg-sharing in an assisted conception programme. The currentHFEA guidelines on medical screening of patients, counselling,age and rigid anonymity between the donor and recipient werefollowed. The study involved 55 women (25 donors and 30 recipients)in 73 treatment cycles involving fresh and frozen-thawed embryos.Donors were previous IVF patients who, regardless of their abilityto pay, shared their eggs equally with matched anonymous recipients.They paid only for their consultations and tests right up tothe point of being matched with a recipient The sole recipientpaid the cost applicable in egg donation of a single egg collection,although both received embryo transfers. The results indicatethat although the recipients were older than the donors (41.4± 0.9 versus 31.6 ± 0.5 years), and there wasno difference in the mean number of eggs allocated, the percentagefertilization rates, or the mean number of embryos transferred,there were more births per patient amongst recipients than amongstdonors (30 versus 20%). We conclude that providing the donorsare selected carefully, this scheme whereby a sub-fertile donorhelps a sub-fertile recipient is a very constructive way ofsolving the problem of the shortage of eggs for donation. Thereare also the advantages of including a group of women who wouldotherwise be denied treatment Problems related to patientcoercion can, in our view, be fully overcome by the applicationof strict common-sense safeguards. The ideal of pure altruismis not without its medical and moral risk. The success of egg-sharingdepends on shared interests and a degree of altruism betweenthe donor, the recipient and the centre. The current HFEA guidelinesshould be applauded for enabling a highly effective conceptof mutual help to develop. 相似文献
50.
Identification of the multiple endocrine neoplasia type 1 (MEN1) gene. The European Consortium on MEN1 总被引:10,自引:0,他引:10
Lemmens I; Van de Ven WJ; Kas K; Zhang CX; Giraud S; Wautot V; Buisson N; De Witte K; Salandre J; Lenoir G; Pugeat M; Calender A; Parente F; Quincey D; Gaudray P; De Wit MJ; Lips CJ; Hoppener JW; Khodaei S; Grant AL; Weber G; Kytola S; Teh BT; Farnebo F; Thakker RV 《Human molecular genetics》1997,6(7):1177-1183