全文获取类型
收费全文 | 1637篇 |
免费 | 80篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 104篇 |
妇产科学 | 103篇 |
基础医学 | 138篇 |
口腔科学 | 42篇 |
临床医学 | 169篇 |
内科学 | 326篇 |
皮肤病学 | 45篇 |
神经病学 | 24篇 |
特种医学 | 149篇 |
外科学 | 142篇 |
综合类 | 135篇 |
预防医学 | 100篇 |
眼科学 | 24篇 |
药学 | 110篇 |
1篇 | |
中国医学 | 74篇 |
肿瘤学 | 35篇 |
出版年
2021年 | 15篇 |
2018年 | 13篇 |
2017年 | 19篇 |
2016年 | 14篇 |
2015年 | 33篇 |
2014年 | 43篇 |
2013年 | 43篇 |
2012年 | 49篇 |
2011年 | 48篇 |
2010年 | 54篇 |
2009年 | 44篇 |
2008年 | 45篇 |
2007年 | 37篇 |
2006年 | 37篇 |
2005年 | 18篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 24篇 |
2000年 | 12篇 |
1999年 | 20篇 |
1998年 | 43篇 |
1997年 | 54篇 |
1996年 | 47篇 |
1995年 | 42篇 |
1994年 | 56篇 |
1993年 | 36篇 |
1992年 | 17篇 |
1991年 | 19篇 |
1990年 | 19篇 |
1989年 | 30篇 |
1988年 | 32篇 |
1987年 | 37篇 |
1986年 | 28篇 |
1985年 | 24篇 |
1984年 | 25篇 |
1983年 | 20篇 |
1982年 | 13篇 |
1981年 | 24篇 |
1980年 | 16篇 |
1975年 | 11篇 |
1959年 | 35篇 |
1958年 | 58篇 |
1957年 | 87篇 |
1956年 | 45篇 |
1955年 | 75篇 |
1954年 | 67篇 |
1953年 | 17篇 |
1952年 | 14篇 |
1949年 | 10篇 |
排序方式: 共有1730条查询结果,搜索用时 0 毫秒
61.
Induction of proliferation of B prolymphocytic leukemia cells by phorbol ester and native or recombinant interferon-gamma 总被引:1,自引:0,他引:1
Phorbol ester phorbol myristate acetate (PMA) induces proliferation in nonmalignant human B cells and B cells from a patient with B prolymphocytic leukemia (B-PLL). Mitogen-free T cell-derived conditioned medium acts synergistically with PMA in inducing proliferation of B-PLL cells but does not enhance the PMA-stimulated outgrowth of nonmalignant B cells. Interleukin 2 (IL-2) has no effect on the outgrowth of B-PLL cells, and monoclonal antibodies against the IL-2 receptor do not influence the response to PMA and conditioned medium. Recombinant interferon-gamma (IFN-gamma), in contrast, is a potent enhancer of PMA-induced proliferation of B-PLL cells. With gel filtration techniques and with the use of anti-IFN-gamma antibodies, it is shown that IFN-gamma in the conditioned medium is responsible for the observed increase in B-PLL cell proliferation. Preincubation of B- PLL cells with IFN-gamma induces responsiveness to PMA, whereas IFN- gamma alone had no effect on these cells when pretreated with PMA. The combined data show that, in the presence of PMA, native and recombinant IFN-gamma are growth factors for B cells from a B-PLL patient and that IL-2 is not involved in this process. 相似文献
62.
Wireless Ultrasound Guidance for Femoral Venous Cannulation in Electrophysiology: Impact on Safety,Efficacy, and Procedural Delay 下载免费PDF全文
DANIEL RODRÍGUEZ MUÑOZ M.D. EDUARDO FRANCO DÍEZ M.D. JAVIER MORENO M.D. Ph.D. GIUSEPPE LUMIA M.D. ALEJANDRA CARBONELL SAN ROMÁN M.D. TERESA SEGURA DE LA CAL M.D. ROBERTO MATÍA FRANCÉS M.D. Ph.D. ANTONIO HERNÁNDEZ MADRID M.D. Ph.D. JOSÉ LUIS ZAMORANO GÓMEZ M.D. Ph.D. 《Pacing and clinical electrophysiology : PACE》2015,38(9):1058-1065
63.
Nash RA; Pineiro LA; Storb R; Deeg HJ; Fitzsimmons WE; Furlong T; Hansen JA; Gooley T; Maher RM; Martin P; McSweeney PA; Sullivan KM; Anasetti C; Fay JW 《Blood》1996,88(9):3634-3641
The safety and potential efficacy of FK506 in combination with a short course of methotrexate (MTX) for the prevention of acute graft-versus- host disease (GVHD) after marrow transplantation from HLA-matched unrelated donors was evaluated in a single-arm Phase II study conducted at two centers. Forty-three patients, 15 to 54 (median 41) years of age, were transplanted for hematologic malignancies. Thirty-seven of 43 evaluable patients had evidence of sustained marrow engraftment. Five patients died before day 17 after transplantation. The median time to an absolute neutrophil count of > 0.5 x 10(5)/L was 21 (range, 14 to 30) days. Nephrotoxicity (serum creatinine concentration > 2 mg/dL or doubling of baseline) occurred in 32 patients (74% cumulative incidence during the first 100 days after transplant). Other adverse effects included hypertension (n = 27), hyperglycemia (n = 27), neurotoxicity (n = 9) and thrombotic thrombocytopenic purpura (n = 2). Severe veno- occlusive disease of the liver occurred in 9 (21%) of the 43 patients. Eighteen patients (42%) developed grades II to IV acute GVHD and five (12%) developed grades III to IV acute GVHD. Twelve of 25 evaluable patients developed extensive chronic GVHD within 1 year of marrow transplantation resulting in an estimate of the probability of developing this complication of 48%. The cumulative incidence of transplant-related mortality during the first 100 days was 37%. Kaplan- Meier estimates of disease-free survival at 2 years for good-risk, poor- risk, and all patients were 65%, 4%, and 32%, respectively. FK506 in combination with a short course of MTX appears active in preventing acute GVHD after marrow transplantation from unrelated donors. Further studies comparing the combination of FK506 and MTX with cyclosporine and MTX for the prevention of acute GVHD are warranted. 相似文献
64.
Ca2+ and phospholipid-dependent protein kinase (protein kinase C) activity is not necessarily required for secretion by human neutrophils 总被引:2,自引:0,他引:2
Ca2+-dependent and phospholipid-dependent protein kinase (PKC) is a receptor for and is activated by phorbol esters. This enzyme is reportedly involved in the mechanism of superoxide anion (O2-) production and the release of intracellular granule contents from human neutrophils. As previously reported by others, we found that greater than 75% of the total cellular PKC activity existed in a soluble form in untreated neutrophils and that this activity was enhanced in a dose- dependent manner by phorbol 12-myristate 13-acetate (PMA) and by phorbol 12,13-dibutyrate (PDBu). Furthermore, mezerein, an analogue of PMA that is thought to be a competitive inhibitor, did not activate PKC, and on the contrary, inhibited PMA-stimulated activity in a dose- dependent manner. Pretreatment of intact neutrophils with PMA or PDBu caused the "translocation" of PKC activity to the insoluble cell fraction; PKC translocation was not detected after mezerein stimulation at any of the tested concentrations. Neither did mezerein cause an increase in intracellular Ca2+, as monitored by Quin 2 fluorescence. Both phorbol esters and mezerein stimulated intact neutrophils to generate O2- and release lysosomal enzymes into the extracellular medium. Finally sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated key differences in the patterns of endogenous phosphoproteins of neutrophils stimulated with phorbol as compared with mezerein. We therefore suggest that PKC activation may not be the only pathway required to elicit neutrophil responses. 相似文献
65.
低频率抗Mur抗体引起溶血性输血反应的调查研究 总被引:8,自引:0,他引:8
目的研究抗Mur抗体血型血清学特征,调查其在输血医学中临床意义。方法对2例患者的血清,与已知血型的试剂红细胞和4个已知Mur抗原,在盐水介质、低离子间接抗球蛋白介质,分析鉴定出其抗体的特异性。结果这2例患者与已知血型的试剂红细胞在多种反应介质中的反应结果显示患者血清中含有抗Mur抗体,患者血清与4个已知Mur抗原的反应证实该例抗体只与Mur抗原反应。结论该例同种抗体为特异性抗Mur抗体,在临床会引起溶血性输血反应。在东方人群中Mihenberger血型抗体常规筛选鉴定值得探讨。 相似文献
66.
目的观察低浓度表面活性剂聚氧乙烯蓖麻油,Labrasol和聚山梨酯80对肠黏膜P-gp的调控作用。方法使用体外扩散池法评价罗丹明123(R123)经空肠、回肠和结肠黏膜的经时经吸收方向和分泌方向的透过量和透过系数(Papp),并测定不同浓度表面活性剂对R123和荧光素钠(CF)经肠黏膜透过性的影响。R123和CF在接受室中的浓度用荧光分光光度法测定。结果R123经肠道黏膜的透过性存在部位差,即以空肠、回肠和结肠的次序透过性依次减少。另一方面,R123经肠道分泌方向的透过性显著地高于其吸收方向的透过性。低浓度的CEL和Labrasol可显著增强R123经吸收方向的透过性,减少经分泌方向的透过性;而低浓度的聚山梨酯80可显著增强R123经吸收方向的透过性,但对经分泌方向的透过性无显著影响。但实验浓度的表面活性剂对CF的肠道转运没有影响。结论低浓度的聚氧乙烯蓖麻油、Labrasol和聚山梨酯80可通过对P-gp功能的抑制而用于改善受P-gp介导药物的吸收,有望提高此类药物的口服生物利用度。 相似文献
67.
目的:对蒙药嘎日迪-5味丸的方源考证及其现代研究进展进行综述,为该复方的进一步开发与利用提供依据。方法:采用蒙医文献研究与考证、文献综述方法,从基源、方解、临床应用以及化学成分等方面对蒙药嘎日迪-5味丸研究现状进行总结和分析。结果:蒙药嘎日迪-5最早收载于藏医学家宇妥·云丹贡布于公元8世纪下旬撰写的藏医经典著作《四部医典》,属于蒙药、藏药传统验方,由诃子、麝香、草乌(制)、石菖蒲、木香配伍组成,其他处方都是在使用的过程中,根据临床应用演变而来,具有杀黏、止痛、消肿、燥协日乌素功效。蒙医临床用于治疗黏引起的瘟疫热症、黏虫病、黏性刺痛、维生素C缺乏病、风湿、白喉炭疽、瘰疬疮疡、正偏头痛、疥癣等疾病,疗效显著。结论:蒙药嘎日迪-5方出自《四部医典》,属传统验方,对瘟疫热症、黏虫病、黏性刺痛等黏性疾病疗效显著,具有潜在的开发利用价值。 相似文献
68.
Real‐world medical costs of antiviral therapy among patients with chronic HCV infection and advanced hepatic fibrosis 下载免费PDF全文
69.
T Tuvemo J Gustafsson LA Proos the Swedish Growth Hormone Advisory Group 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(9):928-932
Girls adopted from developing countries often have early or precocious puberty, requiring treatment with gonadotropin-releasing hormone (GnRH) analogues. During such treatment decreased growth velocity is frequent. The aim of this investigation was to study whether the addition of growth hormone (GH) to GnRH analogue treatment improves height velocity and final height in girls with early or precocious puberty. Forty-six girls with early or precocious puberty adopted from developing countries were randomized for treatment with GnRH analogue or a combination of GH and GnRH analogue. After 2 y of treatment the mean growth in the GH/GnRH analogue group was significantly higher, 14.6 cm, compared to 10.9 cm in the control group. The increase in bone age did not differ, while the difference in predicted adult height increased by 2.7 cm in favour of the combination group. Although data on final height are not yet available, combined GH/GnRH analogue treatment for 2 y resulted in a higher growth velocity and predicted final height compared to GnRH analogue treatment alone. 相似文献
70.
OBJECTIVE: To determine if sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infection, risk assessment, and education tools provided as part of office-based primary care reduce adolescent risky sexual behaviors. DESIGN: A randomized intervention trial with 3- and 9-month follow-up. SETTING: Five staff-model managed care sites in Washington, DC (n = 19 pediatricians). PATIENTS: Consecutive 12- to 15-year-olds receiving a general health examination; 81% minority. Participation rate = 215/432 (50%). Nine-month follow-up rate = 197/215 (92%). INTERVENTION: Audiotaped STD risk assessment and education about staying safe (safer = condoms, safest = abstinence). MAIN OUTCOME MEASURES: Adolescent-reported sexual intercourse and condom use. RESULTS: More intervention adolescents reported pediatrician discussion on 11/13 sexual topics. Although more vaginal intercourse (odds ratio [OR] = 2.46, 95% confidence interval [CI] = 1.04-5.84) was reported in the intervention group at 3 months, this was not true of overall sexual intercourse (OR = 1.55, 95% CI =.73-3.32). More sexually active adolescents reported condom use in the intervention group at 3 months (OR = 18.05, 95% CI = 1.27-256.03). At 9 months, there were no group differences in sexual behaviors; however, more signs of STD were reported by the control (7/103) than the intervention group (0/94). CONCLUSIONS: STD risk assessment and education tools administered in a single office visit facilitated STD/HIV prevention education. Any impact on sexual activity and condom use was short-lived. Further research is needed to develop brief, office-based sexual risk reduction for young adolescents. 相似文献