全文获取类型
收费全文 | 438篇 |
免费 | 29篇 |
国内免费 | 112篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 5篇 |
妇产科学 | 5篇 |
基础医学 | 43篇 |
口腔科学 | 3篇 |
临床医学 | 110篇 |
内科学 | 78篇 |
皮肤病学 | 14篇 |
神经病学 | 12篇 |
特种医学 | 41篇 |
外科学 | 28篇 |
综合类 | 69篇 |
一般理论 | 1篇 |
预防医学 | 25篇 |
眼科学 | 7篇 |
药学 | 85篇 |
中国医学 | 15篇 |
肿瘤学 | 37篇 |
出版年
2024年 | 4篇 |
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 20篇 |
2012年 | 27篇 |
2011年 | 20篇 |
2010年 | 16篇 |
2009年 | 15篇 |
2008年 | 23篇 |
2007年 | 78篇 |
2006年 | 22篇 |
2005年 | 27篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 19篇 |
2001年 | 18篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 17篇 |
1997年 | 29篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 16篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1934年 | 2篇 |
排序方式: 共有579条查询结果,搜索用时 31 毫秒
1.
年龄对围术期心率变异性的影响及其临床意义 总被引:2,自引:0,他引:2
目的 :探讨年龄对围术期心率变异性的影响及其临床意义。方法 :选择 15 0例择期手术患者 ,以动态心电图 (DCG)监测围术期心率变异性 (HRV)的变化。于术前 1d内监测至少 12h ,术后监测 48h。患者按年龄分为 5组 :A组 :<5 5岁 ,2 3例 ;B组 :5 5~ 64岁 ,2 2例 ;C组 :65~ 69岁 ,41例 ;D组 :70~ 74岁 ,3 6例 ;E组 :≥ 75岁 ,2 8例。结果 :术前TP、LF随年龄的增长呈明显下降趋势 ,B、C、D、E组TP、LF显著低于A组 ,E组HF、D组LF/HF低于A组 ;术后 1d各组HRV各项指标均明显降低 ,B、D、E组TP和B、C、E组HF显著低于A组 ,D、E组LF/HF低于A组 ;术后 2d ,各组HF ,D、E组TP、LF进一步降低 ,D、E组TP、LF/HF显著低于A组。结论 :围术期自主神经功能受损的程度与年龄有一定的关系 ,表现为 :( 1)年龄愈大 ,术前自主神经功能愈低下 ;( 2 )术后高龄患者迷走神经功能降低幅度相对较大 ,迷走 /交感张力失衡相对更为严重且持续时间长 相似文献
3.
无环鸟苷亲脂性前体药物脂质体的制备及体外抗病毒活性(英文) 总被引:5,自引:0,他引:5
本文通过将无环鸟苷(acyclovir,简称ACV)2’位羟基分别与月桂酰氯或棕榈酰氯进行酯化反应,制得亲脂性前体药物无环鸟苷月桂酸酯和无环鸟苷棕榈酸酯(分别简称为C_(12)-ACV和C_(16)-ACV),使脂质体包封率从ACV的29.9%提高到C_(12)-ACV的95.6%和C_(16)-ACV的97.1%;漏泄实验表明在4℃透析60h后,一半以上的ACV从脂质体中漏泄,而C_(12)-ACV和C_(16)-ACV的滞留率分别为70%和80%;体外抗疱疹病毒的试验中,在最低试验浓度0.044μmol/L时,ACV不显示抗病毒活性,而C_(16)-ACV脂质体抑制细胞病变率达75%,说明前体药物通过与脂质体脂膜的结合增加了药物的进入细胞能力,从而提高了ACV的抗病毒能力。 相似文献
4.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献
5.
Prevalence and aetiology of neurological impairment in extremely low birthweight infants 总被引:2,自引:0,他引:2
J WAUGH MJ O'CALLAGHAN DI TUDEHOPE HA MOHAY YR BURNS PH GRAY YM ROGERS 《Journal of paediatrics and child health》1996,32(2):120-124
Objective : To determine the prevalence and perinatal predictors of cerebral palsy, intellectual impairment, visual impairment and deafness in a cohort of extremely low birthweight (ELBW) infants at two years of age.
Methodology : The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, between July 1977 and February 1990 and who survived to two years. The prevalence of cerebral palsy, intellectual impairment, blindness and deafness was measured by clinical, psychometric and audiological assessment and the association with 24 risk factors examined.
Results : Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associated with ventricular dilatation, intraventricular haemorrhage, necrotizing enterocolitis and multiple birth, though only ventricular dilatation (OR 4.41; 95% Cl 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and was independently associated with ventricular dilatation (OR 15.0; 95% Cl 2.2-102.8), ventilation Fi O2 >80% (OR 3.4; 95% Cl 1.01-11.5), vaginal delivery (OR 3.5; 95% Cl 1.09-11.4) and male sex (OR 6.1; 95% Cl 1.67-22.3). No perinatal predictor was statistically associated with risk of deafness. Retinopathy of prematurity (OR 36.9; 95% Cl 2.8-495.5) was associated with risk of later visual impairment.
Conclusions : Intellectual impairment was associated with a broad range of perinatal variables. Cerebral palsy was associated with fewer variables, all of which were also associated with intellectual impairment. Neurologic injury was associated with male sex and multiple birth, which are not biological insults themselves, but may be markers of susceptibility to injury. 相似文献
Methodology : The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, between July 1977 and February 1990 and who survived to two years. The prevalence of cerebral palsy, intellectual impairment, blindness and deafness was measured by clinical, psychometric and audiological assessment and the association with 24 risk factors examined.
Results : Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associated with ventricular dilatation, intraventricular haemorrhage, necrotizing enterocolitis and multiple birth, though only ventricular dilatation (OR 4.41; 95% Cl 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and was independently associated with ventricular dilatation (OR 15.0; 95% Cl 2.2-102.8), ventilation F
Conclusions : Intellectual impairment was associated with a broad range of perinatal variables. Cerebral palsy was associated with fewer variables, all of which were also associated with intellectual impairment. Neurologic injury was associated with male sex and multiple birth, which are not biological insults themselves, but may be markers of susceptibility to injury. 相似文献
6.
Wu DC; Liu JM; Chen YM; Yang S; Liu SM; Chen LT; Whang-Peng J 《Japanese journal of clinical oncology》1997,27(2):115-118
Hemolytic uremic syndrome spontaneously arises in a few patients with
advanced cancer, but it is more commonly related to the use of certain
chemotherapeutic agents. Mitomycin-C is, etiologically, the most common
causative agent inducing hemolytic uremic syndrome, in a dose dependent
manner. We report this syndrome, attributable to mitomycin-C at a
cumulative dose of 40 mg/m2, in a gastric cancer patient. A 42-year-old
female with stage III gastric cancer underwent radical gastrectomy and was
given mitomycin-C at 10 mg/m2 intravenously every four weeks as adjuvant
therapy. Hemolytic uremic syndrome was diagnosed three months after the
last dose of mitomycin-C administration. The most prominent symptoms
included pallor, hypertension and anasarca, with laboratory evidence of
microangiopathic hemolytic anemia, azotemia and hyperkalemia. Her disease
was progressive, but fortunately stabilized after staphylococcus column A
dialysis. Her disease remained in remission for 24 months from the time of
diagnosis, and then relapsed in the form of peritoneal carcinomatosis with
partial intestinal obstruction.
相似文献
7.
We report a case of cerebral dural sinus thrombosis presenting as acute subarachnoid haemorrhage and clinically mimicking an aneurysmal bleed. Awareness of this rare initial presentation of cerebral venous thrombosis is important and should be considered in the diagnostic work‐up of acute subarachnoid haemorrhage. The radiologist plays a crucial role in making this often unsuspected but important diagnosis to enable prompt appropriate treatment. 相似文献
8.
Heinrich Weßling 《Medicine studies》2014,4(1-4):37-51
Over the last decade in Germany, a number of neuroscientists—and among them most prominently Wolf Singer—have claimed to be able to offer scientific evidence derived from neurophysiologic findings to conclusively negate the existence of human free will. In this paper, Singer’s position is examined according to its principal characteristics in order to answer the question whether it is a novel position as opposed to a position pertaining to one of the traditions of western philosophy and anthropology. Furthermore, we try to judge whether the neurobiological findings Singer and others use to justify their position are apt to satisfy the criteria for the presence of scientific evidence, i.e., if they are good reasons to believe that human will is unfree. 相似文献
9.
肺源性心脏病急性发作期免疫功能的改变 总被引:3,自引:0,他引:3
目的:观察肺源性心脏病(简称肺心病)急性发作期患者免疫功能的变化。方法:选择南华大学附属第一医院2004-11/2006-01收治慢性肺心病急性发作期患者60例为肺心病组,于急性加重期入院第2天7:00,空腹抽取静脉血,采用流式细胞仪检测T细胞亚群CD3 、CD4 、CD8 及自然杀伤细胞活性,免疫浊度法检测体液免疫指标(IgG,IgM,IgA及补体C3)。以同期60例健康体检者为对照。结果:120例是否受试者均进入结果分析。①T细胞亚群:肺心病组CD3 ,CD4 水平低于对照组(0.52±0.06,0.62±0.04;0.32±0.06,0.41±0.06;P均<0.05),CD4 /CD8 高于对照组(1.96±0.26,1.84±0.78,P<0.05)。②免疫血清指标:肺心病组IgA、补体C3及自然杀伤细胞活性低于对照组[(1.26±0.74),(2.45±0.85)g/L;(6200±217),(9960±302)mg/L;0.34±0.08,0.57±0.07;P均<0.05]。结论:肺源性心脏病急性发作期患者的细胞免疫和体液免疫功能均受损,尤以细胞免疫功能受损更突出,且与病情呈平行关系。 相似文献
10.
目的:观察低血糖指数的膳食对2型糖尿病患者氧化应激状态的影响。方法:2004-10/11在上海市静安区二个社区卫生服务中心招募受试者,经医生明确诊断为2型糖尿病、病程超过6个月,体质量指数≥24kg/m2的老年糖尿病志愿者43名,受试者对试验知情同意。采用随机交叉试验随机分配至低血糖指数饮食组和高血糖指数饮食组,每种膳食分别连续使用4周,间隔洗脱期4周,比较试验前后患者超氧化物歧化酶、脂质过氧化产物丙二醛和谷胱甘肽过氧化物酶含量的变化。结果:受试者依从性好,除1人因试验期间发现肿瘤而退出试验,42名志愿者按设计要求完成试验。膳食干预后低血糖指数饮食组和高血糖指数饮食组的超氧化物歧化酶活力分别升高了15.68%和21.33%,丙二醛水平分别下降23.94%和21.55%,谷胱甘肽过氧化物酶活力分别升高了15.74%和17.09%;干预后低血糖指数饮食组丙二醛下降水平与高血糖指数饮食组比较差异有显著性意义(P<0.05),而超氧化物歧化酶和谷胱甘肽过氧化物酶活性两组间差异无显著性意义(P>0.05)。结论:在控制总能量的基础上给予平衡膳食能够改善其氧化应激水平,采用低血糖指数食物有助于氧化应激水平的改善。 相似文献