全文获取类型
收费全文 | 14659篇 |
免费 | 967篇 |
国内免费 | 660篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 304篇 |
妇产科学 | 81篇 |
基础医学 | 1047篇 |
口腔科学 | 26篇 |
临床医学 | 1264篇 |
内科学 | 3606篇 |
皮肤病学 | 36篇 |
神经病学 | 327篇 |
特种医学 | 887篇 |
外国民族医学 | 9篇 |
外科学 | 1781篇 |
综合类 | 2783篇 |
现状与发展 | 3篇 |
预防医学 | 576篇 |
眼科学 | 19篇 |
药学 | 1541篇 |
3篇 | |
中国医学 | 882篇 |
肿瘤学 | 1048篇 |
出版年
2024年 | 28篇 |
2023年 | 211篇 |
2022年 | 310篇 |
2021年 | 423篇 |
2020年 | 362篇 |
2019年 | 370篇 |
2018年 | 356篇 |
2017年 | 479篇 |
2016年 | 474篇 |
2015年 | 496篇 |
2014年 | 855篇 |
2013年 | 835篇 |
2012年 | 820篇 |
2011年 | 905篇 |
2010年 | 745篇 |
2009年 | 807篇 |
2008年 | 795篇 |
2007年 | 826篇 |
2006年 | 777篇 |
2005年 | 637篇 |
2004年 | 486篇 |
2003年 | 506篇 |
2002年 | 402篇 |
2001年 | 368篇 |
2000年 | 345篇 |
1999年 | 264篇 |
1998年 | 254篇 |
1997年 | 235篇 |
1996年 | 242篇 |
1995年 | 208篇 |
1994年 | 202篇 |
1993年 | 147篇 |
1992年 | 144篇 |
1991年 | 151篇 |
1990年 | 87篇 |
1989年 | 103篇 |
1988年 | 84篇 |
1987年 | 61篇 |
1986年 | 56篇 |
1985年 | 72篇 |
1984年 | 51篇 |
1983年 | 35篇 |
1982年 | 44篇 |
1981年 | 41篇 |
1980年 | 41篇 |
1979年 | 33篇 |
1978年 | 23篇 |
1977年 | 27篇 |
1976年 | 18篇 |
1975年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
11.
L. Rosenberg M.D. I. T. Jackson D. Sharpe J. Weiss 《European journal of plastic surgery》1987,9(4):158-159
Summary A system which can be used for injection or infiltration of large volumes of fluid is described. This consists of a syringe which fills automatically from a reservoir through an inlet/outlet valve. 相似文献
12.
影响肝外伤手术死亡的危险因素分析 总被引:3,自引:1,他引:2
目的分析影响肝外伤手术死亡的危险因素,探讨其临床意义。方法根据AAST和ISS标准,回顾性分析90例肝外伤手术病例,对影响手术死亡的危险因素进行单因素比较和Logistic回归分析。结果死亡15例,其中Ⅲ级2例、Ⅳ级4例、Ⅴ级9例,总体手术死亡率17%。Ⅳ~Ⅴ级肝外伤手术方式的单因素比较提示:清创性肝切除术的相对危险度是0.73;而规则性肝切除术、肝静脉或肝后下腔静脉修补术相对危险度分别是1.32、1.52。Logistic回归分析提示:ISS分会和术中失血量是影响手术死亡率的2个独立因素。结论ISS分值、术中失出血量和手术方式是影响肝外伤手术死亡的3个重要因素,娴熟的手术技能和合理的手术方式可以减少术中出血量和降低手术死亡率。 相似文献
13.
14.
因症就诊检出早期大肠癌的临床及病理学特征 总被引:1,自引:0,他引:1
目的探讨在就诊的肛肠病人中如何提高早期大肠癌的检出率。方法在11家医院推广对肛肠病人的四项检查程序——直肠指检,乙结镜检查,大便隐血试验,和X线气钡灌肠造影。结果在4821例有肛肠症状的病人中,检出大肠癌188例,检出率为3.9%,其中180例有术后病理诊断。47/180例(26.1%)属早期癌(DukesstageA)。41/47例由上述四项检查作出初步诊断。初发症状为:(1)便血(26例,持续15.2±9.4周后就诊,肿瘤平均直径2.58cm);(2)大便习惯改变(9例,33.4±19.7周,3.39cm);(3)腹痛腹块(10例,19.2±11.2周,5.0cm);(4)贫血(2例,17.2±9.9周,4.75cm)。8/12例的A0和A1期病例属便血组,并多位于直肠。41/47例以高、中分化腺癌为主,其中15例伴有腺瘤癌变。术前曾作活检的27例中,12例未检出癌变细胞。结论四项检查对检出早期大肠癌是有效的,便血是提示早期癌最有价值的症状,加强大肠癌防治宣教,采用瘤灶多点或全瘤活检技术,高度重视大肠腺瘤和不典型增生等癌前病变,将有助于提高早期大肠癌的检出率 相似文献
15.
J. B. DILAWARI N. NAGPAL Y. K. CHAWLA U. KAUR J. VERMA H. BALI K. M. DAS S. SURI 《Journal of gastroenterology and hepatology》1993,8(2):202-205
Hepatic venous outflow tract obstruction, Budd-Chiari syndrome (BCS), leads to portal hypertension and to the development of collaterals that bypass the obstruction. Described here is a BCS patient with an unusually large transdiaphragmatic collateral between the left hepatic and left innominate veins, which decompressed the oesophageal varices. This has not been reported earlier in the literature. 相似文献
16.
Takakura Yoshinobu Fujita Takuya Hashida Mitsuru Sezaki Hitoshi 《Pharmaceutical research》1990,7(4):339-346
As part of the strategy for the design of macromolecular carriers for drug targeting, the disposition characteristics of macromolecules were studied in mice bearing tumors that served as target tissues. Eight kinds of macromolecules including four polysaccharides and four proteins with different molecular weights and electric charges were used; tissue distribution and tumor localization after intravenous injection were studied. Pharmacokinetic analysis revealed that the tissue radioactivity uptake rate index calculated in terms of clearance was different among the tested compounds; especially, the urinary radioactivity excretion clearances and the total hepatic radioactivity uptake clearances varied widely. Compounds with low molecular weights (approximately 10 kD) or positive charges showed lower tumor radioactivity accumulation; radioactivity was rapidly eliminated from the plasma via rapid urinary excretion or extensive hepatic uptake, respectively. On the other hand, large and negatively charged compounds, carboxymethyl dextran, bovine serum albumin, and mouse immunoglobulin G, showed higher radioactivity accumulation in the tumor (calculated total amounts were 15.6, 10.8, and 20.8% of the dose, respectively) and prolonged retention in the circulation. These results demonstrated that the total systemic exposure rather than the uptake rate index was correlated with total tumor uptake. Molecular weight and electric charge of the macromolecules significantly affected their disposition characteristics and, consequently, determined radioactivity accumulation in the tumor. It was concluded that a drug–carrier complex designed for systemic tumor targeting should be polyanionic in nature and larger than 70,000 in molecular weight. 相似文献
17.
Goichi Yotsumoto Koki Tanaka Naoki Ishizaki Akira Ikoma Sumihiro Kawashima Akira Taira 《Surgery today》1997,27(7):657-660
We report herein a case of spontaneous subcapsular hepatic hemorrhage which occurred in a 33-year-old woman 1 day after she
had been delivered of her second child by cesarean section following an uneventful pregnancy. She complained of right upper
quadrant pain on the 1st postoperative day, and computed tomography (CT) showed subcapsular low-density masses in both liver
lobes, while extravasation was demonstrated by CO2 intraarterial digital subtraction angiography (IADSA). The hemorrhage was successfully controlled by transcatheter arterial
embolization (TAE). However, on the 3rd day after TAE, an exploratory laparotomy was performed to establish an exact diagnosis
to explain the persistent abdominal pain and abnormal liver function tests. Subcapsular hematomas in both lobes were confirmed
and no visible laceration was present. The patient recovered gradually by spontaneous absorption of the hematomas and was
discharged on the 22nd postoperative day. Spontaneous hepatic hemorrhage associated with pregnancy is a very rare complication,
and establishing a correct diagnosis and initiating appropriate therapy are essential for this life-threatening disease. 相似文献
18.
19.
肝腺瘤的影像学诊断 总被引:5,自引:1,他引:4
目的探讨影像学(US、CT、MRI及DSA)诊断肝腺瘤的价值。方法回顾性分析经手术、病理证实的11例肝腺瘤的影像学表现,其中11例行US和CT检查(有1例行CT灌注成像,CTP),5例行MRI扫描,4例行DSA检查,并与手术病理所见对照。结果11例肝腺瘤均为单发肿块,无肝硬化背景,直径2.0~10.0cm。影像学表现:US检查,10例呈稍低或不均匀稍强回声,边界清晰,6例见低回声晕,彩色多普勒显示肿块内有较丰富的血流;CT检查,10例为稍低或等密度,8/10例动脉期全瘤明显强化,门脉期轻度强化,延迟期呈等密度,1例平扫和延迟期呈等密度,动脉期中度强化,门脉期轻度强化,误诊为血管瘤。1/11例CT灌注成像(CTP)检查,肝动脉灌注量(HAP)=1.08ml/(min.ml),门静脉灌注量(PVP)=0.19ml/(min.ml),肝动脉灌注指数(HPI)=0.85,各参数值与肝癌均有明显不同;MRI检查,5例肝腺瘤均能显示完整包膜,T1WI上2例稍高于肝脏信号,1例呈等信号,2例为稍低信号,T2WI上5例均表现为以稍高信号为主的混杂信号,脂肪抑制像(STIR)1例呈略低信号,4例信号与T2WI相似,行增强扫描的4例病灶动脉期显著强化,门脉期强化减退,平衡期呈等信号。DSA检查,3/4例病灶见粗细不均的异常血管影,实质期可见肿瘤染色表现。结论肝腺瘤的US和DSA表现均缺乏特异性,CT、MRI则具有一定的特点。CTP对肝腺瘤可能具有诊断和鉴别诊断价值。 相似文献
20.
目的 研究还原型谷胱甘肽对大鼠肝星状细胞(hepatic stellate,cells,HSC)中金属蛋白酶1组织抑制因子(TIMP-2)表达的影响。从分子和蛋白水平探讨还原型谷胱甘肽对大鼠肝纤维化的作用和可能机制。方法 采用50%CCl4制备大鼠肝纤维化模型,在造模过程中给予还原型谷胱甘肽进行干预。应用RT-PCR才Western Blot技术,在分子和蛋白水平检测体外分离大鼠HSC中的TIMP-1的表达情况。结果 还原型谷胱甘肽干预组与模型组和正常对照组相比,HSC中TIMP的表达降低(P<0.05)。结论 还原型谷胱甘肽的干预可下调大鼠HSC中TIMP-1的表达,对实验性肝纤维化起到减轻作用。 相似文献