全文获取类型
收费全文 | 32801篇 |
免费 | 1980篇 |
国内免费 | 1404篇 |
专业分类
耳鼻咽喉 | 443篇 |
儿科学 | 540篇 |
妇产科学 | 424篇 |
基础医学 | 2630篇 |
口腔科学 | 200篇 |
临床医学 | 3120篇 |
内科学 | 3014篇 |
皮肤病学 | 373篇 |
神经病学 | 310篇 |
特种医学 | 2173篇 |
外国民族医学 | 22篇 |
外科学 | 8402篇 |
综合类 | 5271篇 |
现状与发展 | 1篇 |
预防医学 | 980篇 |
眼科学 | 81篇 |
药学 | 1593篇 |
5篇 | |
中国医学 | 805篇 |
肿瘤学 | 5798篇 |
出版年
2024年 | 49篇 |
2023年 | 336篇 |
2022年 | 705篇 |
2021年 | 972篇 |
2020年 | 941篇 |
2019年 | 827篇 |
2018年 | 853篇 |
2017年 | 823篇 |
2016年 | 1007篇 |
2015年 | 997篇 |
2014年 | 1786篇 |
2013年 | 1524篇 |
2012年 | 1620篇 |
2011年 | 1959篇 |
2010年 | 1806篇 |
2009年 | 1935篇 |
2008年 | 1904篇 |
2007年 | 1996篇 |
2006年 | 1942篇 |
2005年 | 1677篇 |
2004年 | 1487篇 |
2003年 | 1286篇 |
2002年 | 1140篇 |
2001年 | 1078篇 |
2000年 | 939篇 |
1999年 | 660篇 |
1998年 | 613篇 |
1997年 | 509篇 |
1996年 | 414篇 |
1995年 | 349篇 |
1994年 | 323篇 |
1993年 | 225篇 |
1992年 | 224篇 |
1991年 | 160篇 |
1990年 | 130篇 |
1989年 | 106篇 |
1988年 | 111篇 |
1987年 | 107篇 |
1986年 | 88篇 |
1985年 | 90篇 |
1984年 | 60篇 |
1983年 | 38篇 |
1982年 | 59篇 |
1981年 | 35篇 |
1980年 | 44篇 |
1979年 | 40篇 |
1978年 | 33篇 |
1977年 | 30篇 |
1976年 | 26篇 |
1973年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
Laparoscopic enucleation of a renal cell carcinoma 总被引:1,自引:0,他引:1
R. C. Luciani M. Greiner J. C. Clement A. Houot J. F. Didierlaurent 《Surgical endoscopy》1994,8(11):1329-1331
The purpose of this study was to report on the feasibility of laparoscopic excision of renal cell carcinoma. An 81-year-old female with renovascular disease underwent a laparoscopic excisional operation for a 2-cm tumor localized in the left kidney.Pathological evaluation showed a low-grade tumor without any extension through the renal capsule (grade I Hand Broder, stage I Robson). The postoperative course was uneventful; there was minimal postoperative pain. The patient was discharged home on the sixth day. Laparoscopic excision would appear to be a safe and effective technique in selected cases. 相似文献
103.
E. Van de Keift K. De Boulle P. Willems J. -J. Martin P. Selosse B. Van der Auwera 《Acta neurochirurgica》1992,117(3-4):172-177
Summary Inactivation of tumour suppressor genes or anti-oncogenes as well as activation of dominant acting oncogenes seem to be important mechanisms in the pathogenesis of gliomas. We compared constitutional and tumoural genotypes at different restriction fragment length polymorphism loci (RFLP) on chromosomes 10 and 17 in 15 unrelated individualsLoss of heterozygosity (LOH) pointing to chromosomal loss or deletions was detected for at least one chromosme 17 marker in 11 gliomas (astrocytomas grades I–III and glioblastoma multiforme), whereas LOH for chromosome 10 loci was only detected in 3 out of 9 cases of glioblastoma multiforme and was not detected in low grade gliomas. Since LOH for chromosome 10 loci seems to be restricted only to glioblastoma multiforme, it is possible that recessive mutations on chromosome 10 are engaged in tumour progression from astrocytomas to glioblastoma multiforme. As LOH of chromosome 17 markers occurs in astrocytomas as in glioblastoma multiforme, chromosome 17 loci probably are involved in early tumour development. 相似文献
104.
采用20~200U/ml的重组人肿瘤坏死因子(rhTNF-α)处理体外液相培养的人早幼粒白血病细胞珠HL-60,观察到50~200U/ml的小剂量TNF具有诱导其向单核-巨噬细胞途径分化及抑制其增殖的效应。采用细胞总RNA打点杂交技术检测1~100U/mlTNF诱导HL-60细胞早期(12小时内)对其c-myc,c-fos原癌基因表达的影响,发现TNF可抑制c-mycmRNA水平及c-fos短暂性表达增高。结果表明此小剂量rhTNF-α具有诱导白血病细胞分化的效应及调控多癌基因表达的作用。 相似文献
105.
A. Moutabarrik B. Ramdani B.G. Benghanem K. Hachim D. Zaid I. Nakanishi S. Takahara M. Ishibashi 《Transplant international》1994,7(S1):536-538
Abstract Kidney cells are an important source of immunoregulatory molecules that regulate cell-to-cell interactions, which is the key step in the generation of the immunoresponse to alloantigens. In this study we identified the cytokines that are produced by both lymphoid cells and kidney cells when coincubated in mixed kidney lymphocyte cultures (MKLC). The capacity of kidney cells to stimulate the proliferation of effector allogeneic lymphocytes was assayed by incubating irradiated kidney cells and lymphocyte. The cytokine secretion profile in MKLC was investigated by incubating monolayers of kidney cells with effector peripheral blood mononuclear cells (PBMC). The culture supernatants were harvested on days 1, 2, 3, 4, 5, 6, 7, and 8 and assayed for IL-1β, IL-2, IL-6, and TNF alpha using an ELISA. Kidney cells, in comparison to PBMC stimulator cells were poor stimulators of the allo-proliferation even when HLA expression was increased by IFN gamma treatment. Compared to lymphocyte or kidney cells incubated alone, MKLC induced a considerable stimulation of cytokine production. This increase in cytokine production was observed essentially for IL-2 and IL-6 (at day 3, a 10-fold increase in IL-2 and a 5-fold increase in IL-6). This study provided evidence that target kidney cells and effector lymphocyte interactions generate a number of cytokines such as IL-11, IL-2, IL-6, or TNF alpha. These cytokines are known to modulate alloproliferation and generation of cytotoxic J lymphocytes (CTL). 相似文献
106.
A deceased donor (DD) allocation system incorporating net life survival benefit has been proposed. In this system, many kidneys will be shifted to younger recipients, thereby decreasing their waiting times. The goal of this study was to determine the potential effects of altering waiting times on the likelihood of live donor kidney transplantation (LDKT). We analyzed 93,727 waiting list candidates to determine the association of various patient factors with likelihood of LDKT. The proportion of patients receiving LDKT was compared by the median DD waiting time at that patient's transplant center for someone of that patient's age category and race. LDKT was consistently higher as waiting times became longer. After adjusting for all other factors associated with likelihood of LDKT, waiting time remained a significant, independent predictor. Patients with the longest DD waiting times had 2.3-fold higher odds of LDKT (95% CI 2.11-2.58, p < 0.001). In planning the new DD allocation policy, we must account for resulting alterations in LDKT. It is possible that shifting DD kidneys to younger recipients may decrease LDKT or shift it to older recipients, net effects not consistent with the goal of net life survival benefit. 相似文献
107.
目的研究全肝MR灌注成像(MRPI)早期监视兔肝VX2瘤经皮酒精注射(PEI)疗效的价值。方法新西兰大白兔10只,经开腹手术于肝内注射VX2肿瘤细胞悬液0.1ml,分别在种瘤后第2、3周进行MRT。WI、T2WI检查监视肿瘤生长情况。在种瘤后第3周时,于CT引导下,于肿瘤一侧的早期强化最明显处注射无水乙醇1.0ml,治疗1周后应用MRPI观察治疗效果。灌注参数包括:对比剂到达时间(T0)和最大上升斜率(ss),应用t检验比较治疗区与肿瘤未治疗区的灌注参数。结果10只兔肿瘤均种植成功,第3周时肿瘤直径(2.6±0.6)cm。治疗过程中3只兔死亡,PEI治疗1周后的治疗区呈无或低度强化。肿瘤未治区与治疗区的11D分别为(16.0±1.2)、(50,8±5.9)S,ss分别为38.9±2.2、6.0±1.2,差异均有统计学意义(t值分别为15.8、-39.6,P值均〈0.05)。常规T1 WI、T2 WI无法清晰显示治疗区与未治疗区的差异。结论全肝MRPI可以较敏感的早期监测PEI疗效,早期强化的消失可作为PEI治疗有效的标志。 相似文献
108.
109.
微血管密度和p16基因表达对判定肾癌生物学行为的意义 总被引:1,自引:0,他引:1
目的 :探讨肿瘤内的微血管密度 (IMD)和 p1 6基因表达与肾细胞癌 (RCC)生物学行为的关系。 方法 :采用免疫组织化学方法 ,对 76例RCC患者的根治性肾切除标本 ,检测第Ⅷ因子相关抗原和 p1 6基因表达 ,分析IMD、p1 6基因表达与RCC分期、分级及预后的相关性。 结果 :IMD随临床分期升高而增加 (P <0 .0 5 ) ,而与分级无明显相关性 (P >0 .0 5 ) ,随访 5年内死亡者IMD明显升高 (P <0 .0 1 ) ;癌旁组织中 p1 6阳性率 (75 .0 % )显著高于RCC组织 (4 8.7% ) ,p1 6阳性表达随临床分期、病理分级升高而降低 (P <0 .0 5 ) ,而与IMD呈负相关性。结论 :IMD是预测RCC恶性行为的一个有用指标 ,IMD和p1 6基因表达可为RCC的疗效和预后判定提供重要的资料。 相似文献
110.
pp32表达引起人肝癌细胞HepG2形态改变 总被引:1,自引:1,他引:0
目的:研究pp32在肝癌细胞中的作用.方法:采用RT-PCR的方法钓取pp32全长基因.脂质体介导的方法将pp32基因导入HepG2细胞.观察细胞形态,血清依赖性和接触抑制等细胞表型,测量细胞生长曲线,检测ALP、LDH、γ- GT、ALB和AFP等生化指标.结果:成功钓取了pp32全长基因,筛选获得pp32稳定表达的HepG2细胞株.pp32表达使HepG2细胞伸出细长突起,但不影响HepG2细胞增殖.ALP和LDH酶活力升高,其他指标没有变化.结论:pp32表达引起人肝癌细胞HepG2形态改变,但不改变其恶性表型. 相似文献