全文获取类型
收费全文 | 768篇 |
免费 | 75篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 19篇 |
妇产科学 | 3篇 |
基础医学 | 82篇 |
口腔科学 | 6篇 |
临床医学 | 107篇 |
内科学 | 130篇 |
皮肤病学 | 2篇 |
神经病学 | 15篇 |
特种医学 | 122篇 |
外科学 | 141篇 |
综合类 | 3篇 |
预防医学 | 38篇 |
眼科学 | 10篇 |
药学 | 83篇 |
中国医学 | 1篇 |
肿瘤学 | 35篇 |
出版年
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 24篇 |
2011年 | 24篇 |
2010年 | 22篇 |
2009年 | 10篇 |
2008年 | 21篇 |
2007年 | 39篇 |
2006年 | 34篇 |
2005年 | 27篇 |
2004年 | 9篇 |
2003年 | 18篇 |
2002年 | 24篇 |
2001年 | 26篇 |
2000年 | 19篇 |
1999年 | 15篇 |
1998年 | 27篇 |
1997年 | 23篇 |
1996年 | 19篇 |
1995年 | 26篇 |
1994年 | 21篇 |
1993年 | 16篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 17篇 |
1989年 | 37篇 |
1988年 | 28篇 |
1987年 | 20篇 |
1986年 | 19篇 |
1985年 | 14篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 20篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 24篇 |
1978年 | 12篇 |
1977年 | 15篇 |
1976年 | 9篇 |
1975年 | 13篇 |
1974年 | 5篇 |
1971年 | 5篇 |
1970年 | 3篇 |
排序方式: 共有856条查询结果,搜索用时 15 毫秒
1.
Gutierre Marcela Usberti Telles João Paulo Mota Welling Leonardo Christiaan Rabelo Nícollas Nunes Teixeira Manoel Jacobsen Figueiredo Eberval Gadelha 《Neurosurgical review》2021,44(4):2091-2097
Neurosurgical Review - Cellular response to TBI is a mixture of excitotoxicity, neuroinflammation, and cell death. Biomarkers that can track these lesions and inflammatory processes are being... 相似文献
2.
3.
Eli Vlaisavljevich Gabe Owens Jonathan Lundt Dejan Teofilovic Kimberly Ives Alexander Duryea Jim Bertolina Theodore H. Welling Zhen Xu 《Ultrasound in medicine & biology》2017,43(6):1237-1251
This study investigates the safety profile for use of histotripsy, a non-invasive ultrasonic ablation method currently being developed for the treatment of liver cancer, for liver ablation in an in vivo porcine model. Histotripsy treatments were applied to the liver and hepatic veins of 22 porcine subjects, with half of the subjects receiving systemic heparinization. Vital signs (heart rate, blood pressure, temperature, electrocardiogram and SpO2) were monitored throughout the procedure and for 1 h post-treatment. Blood was drawn at six points during the experiment to analyze blood gases, liver function and free hemoglobin levels. All treatments were guided and monitored by real-time ultrasound imaging. After treatment, the tissue was harvested for histological analysis. Results indicated that histotripsy generated well-defined lesions inside the liver and around the treated hepatic veins of all subjects in both treatment groups. Vital signs and blood analysis revealed that animals responded well to histotripsy, with all animals surviving the treatment. One animal in the non-heparinized group had a transient increase in pH and decreases in blood pressure, heart rate and PCO2 during the 15-min vessel treatment, with these changes returning to baseline levels soon after the treatment. Overall, the results indicate that histotripsy can safely be performed on the liver without the need for systemic heparinization, even in regions containing large hepatic vessels, supporting its future use for the treatment of liver cancer. 相似文献
4.
HT Lam ; SO Schweitzer ; L Petz ; MH Kanter ; DA Bernstein ; S Brauer ; DV Pascual ; BA Myhre ; IA Shulman ; GW Sun 《Transfusion》1997,37(6):577-584
BACKGROUND: The purpose of this study was to search for a more effective transfusion-monitoring system than the existing system of retrospective peer review. STUDY DESIGN AND METHODS: This research used a study-control, preintervention and postintervention design, to evaluate the effectiveness of a prospective physician self-audit transfusion-monitoring system that functioned without the direct involvement of transfusion service physicians. This research also evaluated the effectiveness of issuing to physicians a memo with transfusion guidelines. Three process indicators were used to assess physician behavior at various stages of the blood-ordering process: 1) the number of crossmatches ordered per admission, 2) the transfusion-to- crossmatch ratio, and 3) the number of blood units returned to the laboratory after physician self-auditing. The study used two outcome indicators to reflect overall blood utilization: 1) the percentage of patients who received red cell transfusions and 2) the number of blood units transfused per recipient each month. RESULTS: The prospective physician self-audit system implemented at the study hospital did not reverse physician transfusion decisions, and the process of issuing to physicians a memo with transfusion guidelines at the control hospital failed to reduce blood usage. However, a transient reduction in blood utilization was observed at the study hospital. CONCLUSION: The reduction was hypothesized to be due to a Hawthorne effect, in which observed behavior is affected by the subject's awareness of the research study. 相似文献
5.
Immune inhibition of virus release from human and nonhuman cells by antibody to viral and host cell determinants. 总被引:1,自引:0,他引:1
D M Shariff J Davies M Desperbasques M Billstrom H J Geerligs G W Welling S Welling-Wester A Buchan G R Skinner 《Intervirology》1991,32(1):28-36
Immune inhibition of release of the DNA viruses, herpes simplex virus types 1 and 2 and pseudorabies virus by anti-viral and anti-host cell sera occurred while two RNA viruses, influenza and encephalomyocarditis, were inhibited only by anti-viral sera (not anti-host cell sera). Simian virus 40 and surprisingly two herpes viruses, bovine mamillitis and equine abortion, were not inhibited by either anti-viral or anti-host sera. Using the herpes simplex virus model, inhibition of virus release was detected in different cells of human and nonhuman origin with cross-inhibition between cell lines of different origin; thus, this form of immunotherapy may not require antibody to be tissue or organ specific. Evidence of inhibition of virus release from neoplastic and leukemic cell lines suggests possible application of this approach to control of virus-mediated leukoproliferative pathology (e.g. Burkitt's lymphoma or adult T cell leukemia). 相似文献
6.
Prenatal identification of potential donors for umbilical cord blood transplantation for Fanconi anemia 总被引:1,自引:0,他引:1
AD Auerbach ; Q Liu ; R Ghosh ; MS Pollack ; GW Douglas ; HE Broxmeyer 《Transfusion》1990,30(8):682-687
Reported here are studies of Fanconi anemia fetal cells that led to the first use of umbilical cord blood for hematopoietic reconstitution in a clinical trial. Prenatal diagnosis and HLA typing were performed in fetuses at risk for Fanconi anemia (FA) to identify, prior to birth, those that were unaffected with the syndrome and were HLA-identical to affected siblings. Umbilical cord blood was harvested at the delivery of these infants; assays of progenitor cells indicated the presence of colony-forming units-granulocyte-macrophage (CFU-GM) in numbers similar to those of bone marrow CFU-GM that are associated with successful engraftment in HLA-matched allogeneic bone marrow transplantation. The possibility that umbilical cord blood from a single individual can be used as an alternative to bone marrow for hematopoietic reconstitution has now been demonstrated by the successful engraftment of two patients with FA. Progenitor cell assays of umbilical cord blood collected at the birth of a child affected with FA, who had been misdiagnosed on the basis of chorionic villus sampling (CVS) studies, indicated a profound deficiency in colony formation, consistent with previously reported abnormalities in the growth of FA cells in vitro. These results suggest that the hematopoietic disorder in FA is related to an underlying problem with cell proliferation. 相似文献
7.
8.
目的:建立恢复种植体周围骨缺损的自体骨碎末骨移植材料的实验模型。方法:实验于2005-08/2006-04在大连医科大学动物实验基地(辽宁省重点实验室)完成。①实验材料:健康杂交家犬5只,体质量15~20kg。Bio-Oss骨移植材料为引导骨/组织再生多孔骨无机材料,白色颗粒状,颗粒大小1.0~2.0mm。②实验方法:拔除家犬下颌第1,2,3前臼齿,3个月后行种植术。预备种植体窝,每只犬左右两侧各预备4个,共40个。在每个种植窝内,各植入种植体钛钉1枚,共40枚。用种植转孔时收集的自体骨碎末、Bio-Oss骨移植材料及两者1∶1混合骨碎末恢复种植体颊侧单壁人为骨缺损,以未植骨作空白对照。③实验评估:第9周时观察各组骨量的恢复情况、X线片观察牙槽骨高度、骨小梁致密度及骨整合情况,亚甲基蓝-碱性品红法观察组织学变化。结果:5只家犬钛钉均无脱落,均纳入结果分析。①一般情况:9周时,创口愈合均良好,钛钉稳定,总存留率为100%。骨缺损处已有不同程度恢复,与正常骨组织无明显差别。②9周时各组骨缺损量的测量结果:植入自体骨碎末、Bio-Oss骨移植材料、混合骨碎末及空白对照组的平均骨缺损量分别为1.8125、1.6975、1.5025、2.6375mm。植入混合骨碎末的平均骨缺损量最小,说明恢复最佳。③X线观察骨量的恢复情况:40颗钛钉外周均与骨组织紧密接触,愈合良好。不同组间未见明显骨质密度区别。④组织学观察骨量的恢复情况:低倍镜下见所有钛钉均被周围淡红色的致密骨组织紧密包绕,种植体与骨组织间无蓝色的软组织,产生了直接骨结合界面。结论:应用家犬建立自体骨碎末移植材料恢复种植体周围骨缺损的实验模型效果理想。 相似文献
9.
BRUMFITT W; HAMILTON-MILLER JMT; SMITH GW; AL-WALI W 《QJM : monthly journal of the Association of Physicians》1991,81(1):811-820
SUMMARY Eighty-eight women with a history of recurrent urinary tractinfection (at least four attacks in the preceding 12 months)were randomized to take either norfloxacin 200 mg at night (45patients) or macrocrystalline nitrofurantoin 100 mg at night(43 patients) for 12 months. A decrease in the number of symptomaticattacks while taking this prophylaxis was observed in 94 percent of the patients and this improvement was maintained duringthe 6 months following the end of prophylaxis in 69 per cent.The mean interval between symptomatic episodes while takingprophylaxis was 7.2-fold and 6.9-fold greater, respectively,than in the 12 months before starting prophylaxis. There wereonly nine breakthrough infections during 74 patient-years ofprophylaxis, four in patients taking norfloxacin (two enterococci,one Staphylococcus epidermidis, one Escherichia coli), and fivein those taking macrocrystalline nitrofurantoin (four E. coli,one Klebsiella pneumoniae). Adverse events caused four patientstaking norfloxacin (8 per cent) and seven taking macrocrystallinenitrofurantoin (14 per cent) to stop prophylaxis. Norfloxacinhad a marked suppressive effect on the coliform part of thefaecal flora, with no emergence of resistance. Thus, norfloxacinappears to be an excellent alternative agent to macrocrystallinenitrofurantoin for the prevention of recurrent urinary infections. 相似文献
10.
H L Muytjens G L van Veldhuizen G W Welling J van der Ros-van de Repe H B Boerema D van der Waaij 《Antimicrobial agents and chemotherapy》1983,24(6):902-904
The possible use of pipemidic acid for preventing infections in granulocytopenic patients by selective elimination of the gram-negative rods from the digestive tract was evaluated. Fecal samples were collected before, during, and after therapy from 23 adults who were undergoing treatment of urinary tract infections with pipemidic acid at a dosage of 200 mg orally four times daily for 10 days. The concentration of pipemidic acid in the majority of the stool samples tested was 220 to 600 micrograms/g. However, in 19% of the samples collected on day 5, the concentration was below the detection limit (23 micrograms/ml). Approximately 90% of the fecal samples collected during or shortly after therapy were negative for members of the family Enterobacteriaceae. Resistance of the gastrointestinal tract against colonization by microorganisms from the environment (so-called colonization resistance) remained unimpaired, as measured by the absence of beta-aspartylglycine in the stool. 相似文献