全文获取类型
收费全文 | 619篇 |
免费 | 41篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 42篇 |
妇产科学 | 2篇 |
基础医学 | 47篇 |
口腔科学 | 12篇 |
临床医学 | 63篇 |
内科学 | 130篇 |
皮肤病学 | 6篇 |
神经病学 | 13篇 |
特种医学 | 228篇 |
外科学 | 39篇 |
综合类 | 32篇 |
预防医学 | 22篇 |
眼科学 | 4篇 |
药学 | 11篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 17篇 |
2009年 | 26篇 |
2008年 | 9篇 |
2007年 | 16篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 17篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 11篇 |
1998年 | 46篇 |
1997年 | 48篇 |
1996年 | 38篇 |
1995年 | 22篇 |
1994年 | 40篇 |
1993年 | 25篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 28篇 |
1988年 | 20篇 |
1987年 | 18篇 |
1986年 | 25篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 24篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 10篇 |
排序方式: 共有676条查询结果,搜索用时 15 毫秒
11.
Factors that affect human hemopoiesis are produced by T-cell growth factor dependent and independent cultured T-cell leukemia-lymphoma cells 总被引:3,自引:0,他引:3
Some laboratory results and clinical situations suggest that human T cells may be important in the regulation of growth of hematopoietic cells. Since the discovery of T-cell growth factor (TCGF), systems are now available for the long-term specific in vitro propagation of mature normal or neoplastic human T cells, providing an opportunity to study the influence of T cells on hematopoiesis. Recently, 24 cell lines from patients with cutaneous T-cell lymphoma (CTCL) and T-cell acute lymphoblastic leukemia (T-ALL) were grown with TCGF and then assessed for release of humoral factors that affect hematopoiesis. Conditioned media (CM) from these cell lines were tested for erythroid burst- promoting activity (BPA) and granulocyte colony-stimulating activity (CSA). BPA was detected in CM from 3/6 cultures of T-ALL patients and 4/6 CTCL cultures. CSA was found in the CM from 6/8 cultures of T-ALL patients, 7/12 CTCL cultures, and 3/4 CTCL cell lines that become independent of exogenous TCGF for growth. The CSA from several of the neoplastic T-cell cultures stimulated high levels of eosinophil colonies, a possible source of the eosinophilia seen in these patients. The ability of continuously proliferating human T lymphocytes, which retain functional specificity and responsiveness to normal humoral regulation, to produce factors that directly or indirectly stimulate myeloid and erythroid colony formation lends further credence to the role of T lymphocytes in regulating hematopoiesis. 相似文献
12.
13.
Hemostatic plug (HP) formation was investigated in the ear bleeding time incision in normal and von Willebrand pigs. HP volume was calculated by integrating the areas of serial sections. In normal pigs (n = 11), platelets immediately formed a layer on the surface of the cut channel. Platelet aggregates formed at the ends of transected vessels and gradually enlarged. Finally, all transected vessels were occluded by HP and bleeding stopped. In contrast, large HPs were formed in the incision in von Willebrand's disease (vWD) pigs (n = 4); these HPs did not cover the ends of the transected vessels, which continued to bleed, allowing the formation of large hemostatically ineffective platelet aggregates in the incision. Canals traversed these HPs, and bleeding from the open vessels may have continued through them. After infusion of cryoprecipitate into a vWD pig, the bleeding time shortened, and the morphological findings of the HPs were similar to those of normal pigs. In normal pigs (n = 3) infused with an anti- Willebrand factor monoclonal antibody, which prolonged the bleeding time, a large HP formed in the incision, similar to that observed in the vWD pig. The volume of the normal and vWD HPs increased with time. These in vivo findings suggest that Willebrand factor is involved in the localization of the HP to the damaged vessel and may also play a role in platelet-platelet interaction. A computerized morphometric technique was used for measuring the volume of the hemostatic plugs and the distance of sequential points on the perimeter of the HP from the center of selected bleeding vessels. 相似文献
14.
15.
RC Baker RAJ Spence M Boohan A Dorman M Stevenson SJ Kirk K McGlade 《The Ulster medical journal》2015,84(1):30-36
Background:
Undergraduate surgery is at an important crossroads. Many departments report significant difficulties delivering effective teaching. Our student feedback indicated a dated surgical curriculum lacking structure, quality and uniformity. We report on a new ”blended” approach employing a combination of professional DVDs, case based discussions, online material and traditional bedside teaching designed to provide structure, standardization, and equality of learning .Methods:
Year 4 students who had undertaken the new course and year 5 students who had participated in the traditional teaching programme were compared. Students completed a 20 item questionnaire about their experiences of the surgical teaching programme.Results:
One hundred and seventy-one year 4 (70%) and148 year 5 students (66%) responded. Domains relating to “Overall Satisfaction with the course”, “Approval of innovative teaching methods and interactivity” and “Satisfaction with the clarity of course information” showed improvements when comparing the new and old programmes. However bedside teaching was not rated as highly in the new programme (p<0.05).Conclusion:
This blended approach has resulted in improved student understanding and engagement. The apparent compromise of bedside teaching may be a reflection of higher expectations. We believe that a similar blended approach has the potential to re-invigorate surgical teaching elsewhere. 相似文献16.
Objective:To investigate the wound healing properly of Napoleona vogelii leaf extract in folkloric medicine.Methods:Roth sexes of adult albino rats(n=25) were used in this study and another group(n=30) were subjected to acute toxicity test(LD_(50)) of the plant extract.For the LD_(50),three randomized groups of 5 rats were first treated with 10,100,1 000 mg/kg body weight(bw),orally.This w as followed by a second treatment of 1500,3000,and 5 000 mg/kg bw of the leaf extract with continual monitoring of the animals for mortality or non-mortality.Incision wounds(1.3cm) were created on the skin of five groups of 5 rals using surgical blade under anesthesia.The first group was topically treated with petroleum jelly alone,group 2 was topically applied 400 mg/mL w/v of the reference drug,Neobaein,while group 3-5 were topically treated with 5-50 mg/mL w/v of the plant extract,respectively.Results:The percentage yield of the extract was 49.80%w/w dry matter.The phytochemical analysis revealed several bioactive constituents including glycosides,tannins,alkaloids,perpenoids.saponins,steroids,proteins,and carbohydrates.The LD_(50) was beyond our experimental limit and was not determined.Increased concentrations(5,20,and 50mg/mL w/v) of the extract had significant(ANOVA,P0.05) healing effect on the incision wounds giving rise to 125%-140% while treatmentawith Neobacin resulted in 150% healing effect on the third treatment regimen compared to the control(100%).Conclusions:These data indicate that Napoleona vogelii leaf extract contains potent bioactive compounds containing wound healing activity,substantiating its use as a wound healer in folkloric medicine. 相似文献
17.
Pereira-Cenci T Pereira T Cury AA Cenci MS Rodrigues-Garcia RC 《The International journal of prosthodontics》2007,20(3):308-310
This study aimed to determine the influence of surface roughness (Ra), surface free energy (SFE), saliva, and bacteria on Candida adhesion to denture materials. The Ra and SFE of 2 acrylic resin specimens and 2 denture liner specimens were measured and assayed in a flow chamber for bacteria culture perfusion plus Candida albicans or C glabrata cultures. Adhesion was determined by counting under light microscopy. Candida adhesion showed significant differences depending on the factors involved. The overall colonization was significantly decreased by saliva and influenced by bacteria. Candida adhesion was strongly affected by Ra, saliva, and bacteria, but not by SFE. 相似文献
18.
19.
JL Adams M Murray N Patel MT Sawkin RC Boardman C Pham H Kaur D Patel JL Yager L Pontiggia J Baxter 《HIV medicine》2021,22(1):28-36
20.
Retrovirally marked CD34-enriched peripheral blood and bone marrow cells contribute to long-term engraftment after autologous transplantation 总被引:16,自引:17,他引:16
Dunbar CE; Cottler-Fox M; O'Shaughnessy JA; Doren S; Carter C; Berenson R; Brown S; Moen RC; Greenblatt J; Stewart FM 《Blood》1995,85(11):3048-3057
We report here on a preliminary human autologous transplantation study of retroviral gene transfer to bone marrow (BM) and peripheral blood (PB)-derived CD34-enriched cells. Eleven patients with multiple myeloma or breast cancer had cyclophosphamide and filgrastim-mobilized PB cells CD34-enriched and transduced with a retroviral marking vector containing the neomycin resistance gene, and CD34-enriched BM cells transduced with a second marking vector also containing a neomycin resistance gene. After high-dose conditioning therapy, both transduced cell populations were reinfused and patients were followed over time for the presence of the marker gene and any adverse effects related to the gene-transfer procedure. All 10 evaluable patients had the marker gene detected at the time of engraftment, and 3 of 9 patients had persistence of the marker gene for greater than 18 months posttransplantation. The marker gene was detected in multiple lineages, including granulocytes, T cells, and B cells. The source of the marking was both the transduced PB graft and the BM graft, with a suggestion of better long-term marking originating from the PB graft. The steady- state levels of marking were low, with only 1:1000 to 1:10,000 cells positive. There was no toxicity noted, and patients did not develop detectable replication-competent helper virus at any time posttransplantation. These results suggest that mobilized PB cells may be preferable to BM for gene therapy applications and that progeny of mobilized peripheral blood cells can contribute long-term to engraftment of multiple lineages. 相似文献