全文获取类型
收费全文 | 619篇 |
免费 | 37篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 27篇 |
妇产科学 | 3篇 |
基础医学 | 46篇 |
口腔科学 | 10篇 |
临床医学 | 140篇 |
内科学 | 155篇 |
皮肤病学 | 23篇 |
神经病学 | 7篇 |
特种医学 | 115篇 |
外科学 | 38篇 |
综合类 | 46篇 |
预防医学 | 29篇 |
眼科学 | 15篇 |
药学 | 80篇 |
中国医学 | 4篇 |
肿瘤学 | 26篇 |
出版年
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 20篇 |
2014年 | 18篇 |
2013年 | 50篇 |
2012年 | 20篇 |
2011年 | 23篇 |
2010年 | 26篇 |
2009年 | 39篇 |
2008年 | 8篇 |
2007年 | 79篇 |
2006年 | 30篇 |
2005年 | 18篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 38篇 |
1997年 | 31篇 |
1996年 | 30篇 |
1995年 | 24篇 |
1994年 | 25篇 |
1993年 | 18篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 18篇 |
1988年 | 25篇 |
1987年 | 12篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1958年 | 14篇 |
1956年 | 1篇 |
1955年 | 4篇 |
1945年 | 1篇 |
排序方式: 共有770条查询结果,搜索用时 15 毫秒
761.
EA Operskalski ; ER Schiff ; SH Kleinman ; M Busch ; PE Taylor ; WP Parks ; H Lee ; PA Tomasulo ; E Donegan ; M Stuart ; et al. 《Transfusion》1989,29(8):746-748
We interviewed 51 blood donors in four major US metropolitan areas subsequently found to have had antibodies to human T-cell lymphotropic virus (anti-HTLV) in late 1984-early 1985. Sixteen donors (31%) reported that they or a sexual contact had a history of blood transfusion. Twelve donors (24%) reported that they or a sexual contact used intravenous drugs. Ten donors (20%) were blacks born in the southeastern US. Four of the male donors (15%) reported homosexual contact. The most common characteristic was an association with Japan or the Caribbean basin (61%). These results show a broader variation of epidemiologic backgrounds than anticipated. 相似文献
762.
目的:采用两种改良方法体外分离培养脐血间充质干细胞,并观察其成骨分化能力。方法:实验于2006-05/09在上海交通大学医学院附属第九人民医院骨与关节中心细胞实验室完成。①所用28份脐血标本由复旦大学医学院附属妇产科医院提供,取自足月健康顺产新生儿,产妇和家属均书面同意,实验经医学伦理委员会批准。②采集28份脐血标本,50~90mL/份,枸橼酸抗凝。采集后12h内密度梯度离心法分离出单个核细胞,接种于100mm×20mm培养皿中,细胞浓度为1×1010L-1,置于含体积分数为0.1胎牛血清的α-MEM培养液中原代培养,5~7d后半量换液,后每隔3~4d全量换液一次。③细胞贴壁后,分两组予以改良培养。改良1组10份,当培养皿底圆形巨核细胞融合、梭形成纤维样细胞脱落时将细胞悬液移入新的培养皿中培养;改良2组18份,待培养皿底圆形巨核细胞渐渐占据优势时,将培养基更换为含体积分数为0.15小牛血清的α-MEM,当圆形巨核细胞大部脱落后换回含体积分数为0.1胎牛血清的α-MEM培养基。成纤维样细胞融合至80%~90%时胰酶消化,按1∶2或1∶3传代培养。④显微镜下观察脐血间充质干细胞的形态。取第5代脐血间充质干细胞,采用流式细胞仪测定细胞免疫表型,以碱性磷酸酶法检测成骨分化能力。结果:①28份脐血间充质干细胞中,共20份原代培养中出现贴壁细胞(改良1组6份,改良2组14份),其中13份培养出能融合且可稳定传代的成纤维样细胞(改良1组4份,改良2组9份),成功率46.4%。②原代培养5~7d后贴壁细胞呈梭形成纤维样细胞和圆形巨核细胞。改良1组与2组于原代培养5周可见成纤维样细胞集落,细胞形态与骨髓间充质干细胞相似,呈较均一的长梭形,传至22代形态无明显变化。③可强烈表达CD29、CD105等间充质干细胞表面标志,而不表达CD34、CD45和CD106等造血干细胞和内皮细胞标志。④成骨诱导1周,脐血间充质干细胞可分化为成骨细胞,碱性磷酸酶染色呈阳性。结论:脐血中存在的单个核细胞经过改良培养后,可提高脐血间充质干细胞的培养成功率。脐血间充质干细胞具有与其他来源的单个核细胞类似的表型及成骨分化潜能,且易于体外扩增、传代稳定。 相似文献
763.
764.
外源性肾上腺髓质素对肾脏创伤大鼠Th1/Th2的调节作用 总被引:1,自引:0,他引:1
目的:观察外源性肾上腺髓质素(adrenomedullin,ADM)对大鼠肾脏创伤后外周血Th1/Th2的调节作用,并了解给药时间对此作用的影响。方法:实验于2005年在兰州大学实验中心进行。将104只Wistar大鼠随机分为4大组:①正常对照组(8只);不打击。②创伤组(32只);自由落体生物撞击仪撞击大鼠脊肋区,间接打击双侧肾脏造成肾脏Ⅰ级损伤。③创伤前注射ADM组(32只);打击同创伤组,打击前10min腹腔注射肾上腺髓质素0.1nmol/kg(终体积0.5mL)。④创伤后注射ADM组(32只):打击同创伤组,打击后10min腹腔注射肾上腺髓质素0.1nmol/kg(终体积0.5mL)。后3组分别在打击后1,6,12,24h各处死8只。采用酶联免疫斑点法测定Th1与Th2阳性率。结果:82只大鼠进入结果分析。①创伤组:Th1细胞在创伤后6h显著增加并达峰值,高于创伤后1h及正常对照组[(0.32±0.07)%,(0.13±0.06)%,(0.16±0.07)%,P<0.05,0.01];Th2各时间点比较均无差异;Th1/Th2在创伤后6h达高峰,创伤后24h降至正常对照组水平。②创伤前注射ADM组:Th1在创伤后6h低应答,在创伤后12h增高并达峰值,高于创伤后6h及正常对照组[(0.32±0.08)%,(0.08±0.06)%,(0.16±0.07)%,P<0.05,0.01];Th2在创伤后6-12h的变化趋势与Th1相同;Th1/Th2创伤后6h达最低,低于该时点创伤组(4.58±3.81,23.44±6.19,P<0.01),随后上升,至创伤后24h达高峰。③创伤后注射ADM组:Th1自创伤后1h逐渐上升,至24h达高峰,高于创伤后1,6h[(0.32±0.10)%,(0.10±0.04)%,(0.17±0.07)%,P<0.05,0.01],Th2细胞各时间点比较均无差异;Th1/Th2于创伤后1,6h接近正常对照组,然后逐渐上升,至创伤后24h达最高,高于正常对照组及该时点创伤组(22.49±12.64,5.33±4.55,4.78±3.15,P<0.01)。结论:①急性创伤早期(以创伤后6h为著),外源性肾上腺髓质素通过抑制Th1优势应答,具有校正Th1/Th2比例失衡的免疫调节作用。②急性创伤后最初6h内,创伤后给予肾上腺髓质素调节Th1/Th2平衡作用明显优于创伤前给药。 相似文献
765.
Bacterial meningitis in patients with nasopharyngeal carcinoma 总被引:2,自引:1,他引:2
Bacterial meningitis was found in 12 patients with nasopharyngeal
carcinoma, accounting for 0.65% of the 1850 patients with the tumour
diagnosed between 1981 and 1994 in our hospital. In 11 patients, the
time-lag between diagnosis of cancer and the appearance of infection ranged
from 9 months to 11 years (mean 57 months) whereas in one patient it was
only 5 days. Three patients developed mixed bacterial meningitis.
Cerebrospinal fluid culture for bacteria was positive in six patients.
Three patients (25%) were bacteraemic. Gram-negative bacilli, especially
Pseudomonas aeruginosa, were the most common pathogens. Age, sex and
histopathology were not risk factors for infection. Conditions predisposing
to meningitis included intracranial invasion of the tumor, neutropenia,
otitis media, and neurosurgical procedures. All but two patients had
intracranial tumour invasion and erosion of the base of the skull. Local
spread of micro-organism to the meninges was more important than
haematogenous spread. The overall mortality in our patients was 66.7%, much
higher than in patients without cancer.
相似文献
766.
目的:探讨表皮下自身免疫性大疱病疱液中抗基底膜带(BMZ)自身抗体的情况及在诊断中的意义。方法:应用非盐裂皮肤及盐裂皮肤间接免疫荧光技术(IF)检测38例表皮下自身免疫性大疱病患者疱液和血清中IgG、IgA、IgM、IgE及IgG亚型IgG1~IgG4抗BMZ抗体及滴度,并检测疱液和血清中结合补体C3的特异性抗BMZ抗体。结果:(1)疱液和血清中抗BMZ抗体及滴度和结合补体C3的特异性抗BMZ抗体均无显著性差异。(2)大疱性类天疱疮患者的疱液和血清中IgG抗BMZ抗体的亚型分布相同,主要为IgG1和IgG4。结论:疱液可作为IIF检测表皮下大疱病抗BMZ抗体的另一个有价值的标本来源。 相似文献
767.
Effects of repetitive superficial chemical peels on facial sebum secretion in acne patients 总被引:1,自引:0,他引:1
SH Lee CH Huh KC Park SW Youn 《Journal of the European Academy of Dermatology and Venereology》2006,20(8):964-968
BACKGROUND: Glycolic acid and Jessner's solution are popular superficial chemical peel agents for the treatment of facial acne, and increased sebum secretion is one of the major aetiological factors of acne. OBJECTIVE: To compare the effects of 30% glycolic acid peels and Jessner's solution peels on sebum secretion in facial acne patients. METHODS: Thirty-eight patients with mild to moderate facial acne were included. Twenty-seven patients were treated with 30% glycolic acid peels and 11 patients with Jessner's solution peels. Each peel was performed twice with an interval of 2 weeks. Before and 2 weeks after each peel, sebum levels of forehead, nose, chin and cheeks were measured by using a Sebumeter (SM810 Courage & Khazaka, Cologne, Germany). RESULTS: The sebum levels were not significantly changed by two peels treatments of 30% glycolic acid peels or Jessner's solution peels on the facial skins of patients with facial acne. CONCLUSIONS: The two types of peels, 30% glycolic acid peels and Jessner's solution peels, did not affect sebum secretion of the facial skins of patients with facial acne after the two peels treatments. The accumulative effects of more than two peels treatments using these modalities need further evaluation. 相似文献
768.
769.
Vesico-ureteric reflux and other risk factors for renal damage: identification of high- and low-risk children 总被引:3,自引:0,他引:3
This article reviews the literature with respect to various risk factors for permanent renal damage in children with urinary tract infection. Vesico-ureteric reflux is an important risk factor, but renal damage can occur in the absence of reflux. Renal damage does not always occur in the presence of gross reflux. Renal scars always develop at the same site as a previous infection in the kidney. Recurrent pyelonephritis and delay in therapy increase the likelihood of renal damage, although it is not known how long a delay is dangerous to the human kidney. Recent studies using 99m technetium-dimercaptosuccinic acid (DMSA) scintigraphy have not confirmed the findings of previous studies showing that children below 1 y of age are more vulnerable to renal damage. It is more likely that all children run the risk of renal scarring in cases of acute pyelonephritis. The role of bladder pressure is still not entirely understood. Therefore more studies are needed in order to determine the relationship between high voiding pressures in some, otherwise healthy, children with urinary tract infection and renal scarring. The importance of bacterial virulence in the development of renal scarring is unclear. DMSA scintigraphy and voiding cystourethrography are the most reliable tools for identifying children at risk of renal scarring. As a single method DMSA scintigraphy appears to be better than voiding cystourethrography. 相似文献
770.
Quincy K. Tran Francis O’Connell rew Hakopian Marwa SH Abrahim Kamilla Beisenova Ali Pourmand 《世界急诊医学杂志(英文)》2023,14(1):3
BACKGROUND: When critically ill patients require specialized treatment that exceeds the capability of the index hospitals, patients are frequently transferred to a tertiary or quaternary hospital for a higher level of care. Therefore, appropriate and efficient care for patients during the process of transport between two hospitals (interfacility transfer) is an essential part of patient care. While medical adverse events may occur during the interfacility transfer process, there have not been evidence-based guidelines regarding the equipment or the practice for patient care during transport. 相似文献