全文获取类型
收费全文 | 615篇 |
免费 | 52篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 53篇 |
妇产科学 | 9篇 |
基础医学 | 89篇 |
口腔科学 | 15篇 |
临床医学 | 70篇 |
内科学 | 93篇 |
皮肤病学 | 19篇 |
神经病学 | 22篇 |
特种医学 | 37篇 |
外科学 | 52篇 |
综合类 | 17篇 |
预防医学 | 20篇 |
眼科学 | 8篇 |
药学 | 48篇 |
肿瘤学 | 120篇 |
出版年
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 11篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 30篇 |
2012年 | 22篇 |
2011年 | 15篇 |
2010年 | 22篇 |
2009年 | 28篇 |
2008年 | 23篇 |
2007年 | 17篇 |
2006年 | 18篇 |
2005年 | 25篇 |
2004年 | 15篇 |
2003年 | 14篇 |
2002年 | 18篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 12篇 |
1998年 | 21篇 |
1997年 | 20篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 11篇 |
1993年 | 16篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 19篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1971年 | 3篇 |
1970年 | 6篇 |
1969年 | 8篇 |
1968年 | 8篇 |
1967年 | 3篇 |
排序方式: 共有681条查询结果,搜索用时 15 毫秒
101.
B J Kitchen A Moser E Lowe F M Balis B Widemann L Anderson J Strong S M Blaney S L Berg M O'Brien P C Adamson 《The Journal of pharmacology and experimental therapeutics》1999,291(2):870-874
Thiopurine antimetabolites have been in clinical use for more than 40 years, yet the metabolism of thiopurines remains only partially understood. Data from our previous pediatric phase 1 trial of continuous i.v. infusion of thioguanine (CIVI-TG) suggested that TG was eliminated by saturable mechanism, with conversion of the drug to an unknown metabolite. In this study we have identified this metabolite as 8-hydroxy-thioguanine (8-OH-TG). The metabolite coeluted with the 8-OH-TG standard on HPLC and had an identical UV spectrum, with a lambda(max) of 350 nm. On mass spectroscopy, the positive ion, single quad scan of 8-OH-TG yielded a protonated molecular ion at 184 Da and contained diagnostic ions at m/z 167, 156, 142, and 125 Da. Incubation of TG in vitro with partially purified aldehyde oxidase resulted in 8-OH-TG formation. 8-OH-TG is the predominant circulating metabolite found in patients receiving CIVI-TG and is likely generated by the action of aldehyde oxidase. 相似文献
102.
目的:用HPLC和电荷转移络合UV法分别测定特非那丁粒剂的含量,并对测定结果进行比较,方法:HPLC法,色谱柱:SpherisorbC8(150*4.6mm,5μm);流动相:甲醇-0.1mol/L三乙胺磷酸缓冲液(80:20),检测波长235nm。电荷转移络合UV法,利用碘与TFN在氯仿中形成电荷转移络合物的原理,在紫外294nm的波长处测定TFN的含量。结果:两法测定的线性范围和平均回收率分别 相似文献
103.
The study of central nervous system (CNS) leukemia has been hampered by the lack of a suitable animal model. We report that severe combined immunodeficiency (SCID) mice invariably develop rapidly progressive fatal CNS leukemia within 3 weeks after intravenous injection of NALM-6 pre-B acute lymphoblastic leukemia (ALL) cells. Colonization of the dura mater and subarachnoid space, usually of the distal spinal cord with occasional extension into the Virchow-Robin spaces of blood vessels subjacent to the meninges, followed involvement of bone marrow in the skull, vertebrae, and, occasionally, the appendicular skeleton. Occult CNS leukemia was detectable by polymerase chain reaction amplification of human DNA as early as 8 days postinoculation of leukemia cells. We used this in vivo model of human CNS leukemia to examine the therapeutic efficacy and toxicity of intrathecally administered B43 (anti-CD19)-pokeweed antiviral protein (PAP), an anti- B-lineage ALL immunotoxin directed against the pan-B-cell antigen CD19/Bp95. Intrathecal therapy with B43 (anti-CD19)-PAP immunotoxin at nontoxic dose levels significantly improved survival of SCID mice and was superior to intrathecal methotrexate therapy. 相似文献
104.
105.
Mycosis fungoides and Sézary syndrome: Current challenges in assessment,management and prognostic markers 下载免费PDF全文
Charlotte FM Hughes Kate Newland Christopher McCormack Stephen Lade H Miles Prince 《The Australasian journal of dermatology》2016,57(3):182-191
Mycosis fungoides and Sézary syndrome are the most common variants of the cutaneous T‐cell lymphomas. Assessment of a patient with a suspected diagnosis requires thorough history taking and physical examination, in combination with skin biopsy. In some cases flow cytometry, molecular studies and imaging are also required in order to diagnose and stage the disease. Staging is derived from the tumour‐node‐metastasis‐blood classification and is currently our best attempt to stratify prognosis and hence guide management in this complex disease. Many other clinical, biological and pathological factors may help to distinguish groups at risk and predict prognosis more accurately. Management remains heavily guided by staging, such that patients with early‐stage disease generally begin treatment with skin‐directed or local therapies and those with advanced‐stage disease have many treatment options, including chemotherapy, the use of biological agents, local and total body radiotherapy, as well as haematopoietic stem cell transplantation. Besides staging, many other patient‐related factors influence the treatment strategy, particularly where symptom relief is paramount. There are many challenges remaining in the study of Mycosis fungoides and Sézary syndrome and, given the rarity of the disease, concerted worldwide efforts are required to conduct efficient and effective research. 相似文献
106.
107.
108.
109.
Carlijn TI de Betue Sascha CAT Verbruggen Henk Schierbeek Shaji K Chacko Ad JJC Bogers Johannes B van Goudoever Koen FM Joosten 《Critical care (London, England)》2012,16(5):R176
Introduction
Hyperglycemia in children after cardiac surgery can be treated with intensive insulin therapy, but hypoglycemia is a potential serious side effect. The aim of this study was to investigate the effects of reducing glucose intake below standard intakes to prevent hyperglycemia, on blood glucose concentrations, glucose kinetics and protein catabolism in children after cardiac surgery with cardiopulmonary bypass (CPB).Methods
Subjects received a 4-hour low glucose (LG; 2.5 mg/kg per minute) and a 4-hour standard glucose (SG; 5.0 mg/kg per minute) infusion in a randomized blinded crossover setting. Simultaneously, an 8-hour stable isotope tracer protocol was conducted to determine glucose and leucine kinetics. Data are presented as mean ± SD or median (IQR); comparison was made by paired samples t test.Results
Eleven subjects (age 5.1 (20.2) months) were studied 9.5 ± 1.9 hours post-cardiac surgery. Blood glucose concentrations were lower during LG than SG (LG 7.3 ± 0.7 vs. SG 9.3 ± 1.8 mmol/L; P < 0.01), although the glycemic target (4.0-6.0 mmol/L) was not achieved. No hypoglycemic events occurred. Endogenous glucose production was higher during LG than SG (LG 2.9 ± 0.8 vs. SG 1.5 ± 1.1 mg/kg per minute; P = 0.02), due to increased glycogenolysis (LG 1.0 ± 0.6 vs. SG 0.0 ± 1.0 mg/kg per minute; P < 0.05). Leucine balance, indicating protein balance, was negative but not affected by glucose intake (LG -54.8 ± 14.6 vs. SG -58.8 ± 16.7 μmol/kg per hour; P = 0.57).Conclusions
Currently recommended glucose intakes aggravated hyperglycemia in children early after cardiac surgery with CPB. Reduced glucose intake decreased blood glucose concentrations without causing hypoglycemia or affecting protein catabolism, but increased glycogenolysis.Trial registration
Dutch trial register NTR2079. 相似文献110.
倾斜试验中真假阳性的血流动力学和神经激素的研究 总被引:3,自引:0,他引:3
目的探讨血管迷走性晕厥患者和正常人倾斜试验阳性时不同的触发机制.方法倾斜试验采用静息平卧10min和80°直立30min.心脏监测仪连续监测心率和血压.试验阳性标准为晕厥先兆伴收缩压<90imHg(1mmHg=O.133kPa)和(或)心率<60次/min.超声心动图于基础平卧,直立2min和每隔3min直至试验结束时连续记录左室内径及降低速率,左室短轴缩短分数(SF)和每分心输出量(CO).同时测量平卧和直立时儿茶酚胺血浆浓度.试验分组为正常自愿者且倾斜试验阴性者8例(组1),平均年龄(34±5)岁;正常自愿者伴倾斜试验阳性者8例(组2),平均年龄(31±6)岁;原因不明晕厥伴倾斜试验阳性者16例(组3),平均年龄(30±9)岁.结果三组间年龄、性别以及基础状态下心率,平均动脉压、左室内径、SF、CO和儿茶酚胺血浆浓度无明显差异.直立时各组发生改变为(1)组3出现阳性反应时间明显短于组2[(10±4)min比(17±8)min,P<0.05];(2)组3平均动脉压有即刻和持续性降低;(3)组3左室舒张末期内径降低速率明显大于其他两组;(4)SF在组3显著增强;(5)肾上腺素浓度在组3升高显著,试验终止时组1为(65±35)pg/ml,组2为(78±29)pg/ml,组3为(126±80)pg/ml(P均<0.05);去甲肾上腺素在三组均增高但组间比较差异无显著性.结论血管迷走性晕厥患者和部分正常人倾斜试验虽均呈阳性反应,但血流动力学反应和触发机制不同.前者可能与外周血管张力异常,回心血量及左室容量聚降,肾上腺素分泌增多,促使左室收缩力增强触发Bezold-Jarisch神经反射有关;而后者在发生假阳性反应时,其左室内径和SF及肾上腺素血浆浓度与阴性组无明显不同.倾斜试验时血管迷走性晕厥患者肾上腺素分泌异常在血管舒缩反应损害和左室收缩力异常方面可能起恶化作用. 相似文献