全文获取类型
收费全文 | 10717篇 |
免费 | 777篇 |
国内免费 | 524篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 92篇 |
妇产科学 | 123篇 |
基础医学 | 1673篇 |
口腔科学 | 316篇 |
临床医学 | 575篇 |
内科学 | 1657篇 |
皮肤病学 | 135篇 |
神经病学 | 591篇 |
特种医学 | 329篇 |
外国民族医学 | 6篇 |
外科学 | 629篇 |
综合类 | 1700篇 |
现状与发展 | 4篇 |
预防医学 | 415篇 |
眼科学 | 298篇 |
药学 | 1914篇 |
6篇 | |
中国医学 | 483篇 |
肿瘤学 | 989篇 |
出版年
2024年 | 22篇 |
2023年 | 102篇 |
2022年 | 201篇 |
2021年 | 318篇 |
2020年 | 294篇 |
2019年 | 284篇 |
2018年 | 284篇 |
2017年 | 272篇 |
2016年 | 309篇 |
2015年 | 365篇 |
2014年 | 641篇 |
2013年 | 745篇 |
2012年 | 663篇 |
2011年 | 776篇 |
2010年 | 563篇 |
2009年 | 583篇 |
2008年 | 647篇 |
2007年 | 585篇 |
2006年 | 534篇 |
2005年 | 506篇 |
2004年 | 424篇 |
2003年 | 410篇 |
2002年 | 357篇 |
2001年 | 287篇 |
2000年 | 232篇 |
1999年 | 226篇 |
1998年 | 215篇 |
1997年 | 159篇 |
1996年 | 151篇 |
1995年 | 117篇 |
1994年 | 88篇 |
1993年 | 107篇 |
1992年 | 70篇 |
1991年 | 52篇 |
1990年 | 44篇 |
1989年 | 42篇 |
1988年 | 33篇 |
1987年 | 33篇 |
1986年 | 32篇 |
1985年 | 43篇 |
1984年 | 45篇 |
1983年 | 31篇 |
1982年 | 30篇 |
1981年 | 23篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1973年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
核酸原位杂交程序中探针和靶基因的加热变性和杂交为整个程序中最重要的环节,目前国内外最常用的方法是在切片上滴加DNA探针溶液后用盖玻片复盖组织,并加胶泥或其他封固剂封闭玻片四周,变性杂交后需拆除盖玻片,这一操作过程易损坏组织切片或出现干片、脱片。作者针对上述情况,对传统的核酸原位杂交方法中的部分程序加以改良,采用不加盖玻片直接在蒸汽中变性方法,经多次实验证明此方法稳定、可靠、简便,结果满意。 相似文献
32.
胃癌组织COX-2的表达及其与细胞增殖和凋亡的关系 总被引:8,自引:1,他引:7
目的 :探讨环氧化酶 - 2 (cyclooxygenase - 2 ,COX - 2 )在胃癌组织中的表达与癌细胞增殖和凋亡的关系。 方法 :采用免疫组织化学的方法检测 4 3例胃癌患者COX - 2和增殖细胞核抗原 (PCNA)的表达 ,用TUNEL法检测原位细胞凋亡的情况。分别计算细胞增殖指数 (MI)和凋亡指数 (AI)。结果 :胃癌组织COX - 2表达的阳性率为 6 0 .4 7% ,明显高于对照组 (P <0 .0 1)。COX - 2的高表达与胃癌淋巴结的转移和临床分期有关 ,与肿瘤大小、浸润深度、分化程度均无关。COX - 2阳性胃癌组中MI高于COX - 2阴性胃癌组 ,而AI却低于COX - 2阴性胃癌组 (P均 <0 .0 1)。结论 :COX - 2的过度表达可促进胃癌细胞增殖、抑制细胞凋亡 ,在胃癌的发生、发展过程中起着重要的作用。 相似文献
33.
Keiji Ogura Shigeki Fukuzawa Tomonori Habuchi Osamu Ogawa Osamu Yoshida 《International journal of urology》1997,4(6):561-565
Background :
In an attempt to determine the biological significance of nuclear morphometric findings, measurements of mean nuclear volume (MNV) and nuclear roundness factor (NRF) were compared to the immunoreactivityof p53 expression and proliferating cell nuclear antigen (PCNA) in human bladder cancer.
Methods :
MNV and NRF were measured using stereological methods. Expression of p53 and PCNA were determined by immunohistochemical staining. Specimens from 111 patients with previously untreated bladder cancer were analyzed.
Results :
The mean MNV was 235.8 ± 1 33.6 μm3 for the 81 patients with p53-labeling index (LI) less than 10% and 337.2 ± 141.0 μn3 for the 30 patients with p53 LI greater than 10% (P = 0.008). There was Resign if icant correlation between NRF and expression of p53. The mean MNV was 220.1 ± 1 20.5 μm3 for the 67 patients with PCNA LI less than 28% (the mean value of PCNA LI) and 328.9 ± 149.2 μm3 in 44 patients with PCNA LI greater than 28% (P= 0.0001). The mean NRF was 80.7 ± 4.2 for the 67 patients with PCNA LI less than 28%, and 82.3 ± 3.4 for the 44 patients with PCNA LI more than 28% (P= 0.04). Conclusion: Nuclear morphometric findings may reflect the proliferative potential of cancer eel Is of the bladder, as indicated by findings of immunostaining for p53 and PCNA. 相似文献
In an attempt to determine the biological significance of nuclear morphometric findings, measurements of mean nuclear volume (MNV) and nuclear roundness factor (NRF) were compared to the immunoreactivityof p53 expression and proliferating cell nuclear antigen (PCNA) in human bladder cancer.
Methods :
MNV and NRF were measured using stereological methods. Expression of p53 and PCNA were determined by immunohistochemical staining. Specimens from 111 patients with previously untreated bladder cancer were analyzed.
Results :
The mean MNV was 235.8 ± 1 33.6 μm
34.
大鼠胃黏膜癌变过程中细胞增殖与端粒酶活性关系 总被引:5,自引:0,他引:5
目的 探讨大鼠胃黏膜癌变发生发展过程中DNA含量、增殖细胞核抗原 (proliferatingcellnuclearantigen ,PCNA)及端粒酶活性两者之间的关系。方法 采用甲基硝基亚硝基胍 (MNNG)、10 %NaCl混合液及 40 %乙醇灌胃建立大鼠胃癌模型 ,设立正常组、模型组 ,分别采用免疫组化、流式细胞仪及端粒重复扩增微孔板杂交法检测大鼠胃黏膜PCNA、DNA含量及端粒酶活性。结果 本造模方法可诱发出浅表性胃炎 (chronicsuperficialgastritis,CSG)、萎缩性胃炎 (chronicatrophicgastritis,CAG)、肠化生 (intestinalmetaplasia,IM)、异型增生 (dysplasia,Dys)、胃腺癌(gastricadenocarcinoma,GC)等病变。在大鼠癌变过程中 ,随着胃黏膜癌变的发展 ,DNA含量、增殖细胞核抗原表达及端粒酶活性均呈递增趋势 ,并且两者与端粒酶活性具有高度的相关性 (P <0 .0 1,P <0 .0 1)。结论 大鼠胃黏膜癌变发生发展过程中 ,端粒酶的激活与胃黏膜组织细胞的恶性增殖具有重要的相关性。 相似文献
35.
C.C.-W. YU P.A. HALL C.D.M. FLETCHER R.S. CAMPLEJOHN N.H. WASEEM D.P. LANE D.A. LEVISON 《Histopathology》1991,19(1):29-34
Forty-two cases of haemangiopericytoma were studied retrospectively using immunohistochemical staining with PC10, a monoclonal antibody to PCNA. The percentage of tumour cells with positive staining for PCNA was found to correlate well with histological grading. Clinical follow-up data were available in 25 adults and showed no known deaths in 11 cases with a low proportion (less than 14%) of positive cells. Out of 14 cases with a high number (greater than or equal to 14%) of positive cells, seven patients are known to have died, two had metastases, and in a further two there have been multiple recurrences of tumour. DNA flow cytometry was performed on 26 cases but this showed no correlation with PC10 staining or clinical outcome. Staining with PC10 may be of particular value in the identification of patients at greatest risk of rapid tumour metastasis and early death. 相似文献
36.
胃癌组织中核基质蛋白的变化 总被引:1,自引:1,他引:0
目的:研究胃癌组织核基质蛋白的改变。方法:应用SDS-PAGE技术及Geneools定量分析软件,对22例胃癌组织及正常组织的核心基质蛋白进行了研究,结果:胃癌组织与正常组织比较,Mr为30000,28000的核基质蛋白表达量明显减少(P<0.05),不同分化类型及不同临床分期胃癌组织间比较,此种核基质蛋白表达量差异无统计学意义(P>0.05),结论:胃癌组织中核基质蛋白的改变可能在肿瘤的早期已经发生,是胃癌发生的早期分子事件。 相似文献
37.
Summary Cerebellar nuclear afferents from some caudal brain stem nuclei in the cat were studied by means of retrograde transport after implantation of the wheat germ agglutinin-horseradish peroxidase complex in crystalline form in the cerebellar nuclei. The findings give evidence that projections to the cerebellar nuclei from certain nuclei of the reticular formation proper (e.g., from the gigantocellular reticular nucleus) are very modest, while there appears to be no or extremely few cerebellar nuclear afferents from the paramedian reticular, spinal trigeminal, gracile, cuneate and external cuneate nuclei. Previous tracer studies have given evidence that also the pontine and red nuclei send very few, if any, fibres to the cerebellar nuclei. All these brain stem regions are known to project to the cerebellar cortex. This relative lack of mossy fibre collaterals to the cerebellar nuclei is discussed with references to previous literature on the distribution of cerebellar nuclear afferents, and the problem of how the cerebellar nuclei are facilitated is considered.Abbreviations
Br.c.
superior cerebellar peduncle (brachium conjunctivum)
-
Br.p.
middle cerebellar peduncle (brachium pontis)
-
C.r.
interior cerebellar peduncle (restiform body)
-
HRP
horseradish peroxidase
-
L
left
-
N.c.
cuneate nucleus
-
N.c.e.
external cuneate nucleus
-
N.c.t.
nucleus of corpus trapezoideum
-
NIA
anterior interposed nucleus
-
NIP
posterior interposed nucleus
-
NL
lateral (dentate) nucleus
-
N.l.l.
nuclei of lateral lemniscus
-
NM
medial (fastigial) nucleus
-
N.m.X.
dorsal motor vagal nucleus
-
N.mes.
mesencephalic trigeminal nucleus
-
N.r.l.
lateral reticular nucleus (nucleus of the lateral funiculus)
-
N.r.p.
paramedian reticular nucleus
-
N.r.t.
reticular tegmental pontine nucleus
-
N V, VI, VII, XII
root fibres of cranial nerves
-
Ol.s.
superior olive
-
P.h.
nucleus praepositus hypoglossi
-
Py
pyramid
-
R
right
-
R.gc.
gigantocellular reticular nucleus
-
R.l.
lateral reticular nucleus of Meessen and Olszewski
-
R.p.c.
caudal pontine reticular nucleus
-
R.pc.
parvicellular reticular nucleus
-
R.v.
ventral reticular nucleus
-
Tr.sp.V.
spinal tract of the trigeminal nerve
-
T.s.
solitary tract surrounded by nucleus of solitary tract
-
V.m.
medial vestibular nucleus
-
WGA
wheat germ agglutinin
-
WGA-HRP
wheat germ agglutinin-horseradish peroxidase conjugate
-
V, VI, VII, X, XII
motor nuclei of cranial nerves 相似文献
38.
Leukemia clusters around nuclear facilities in Britain 总被引:1,自引:0,他引:1
Brian McMahon 《Cancer causes & control : CCC》1992,3(3):283-288
He bas been retained for the defense by British Nuclear Fuelsplc in two suits in which leukemia and non-Hodgkin's lymphoma have been alleged to result from radiation exposures due to the operation of the nuclear reprocessing plant at Sellafield. This paper has been sent to the senior authors of the papers reporting clusters of leukemia or other malignancy in the vicinity of nuclear facilities in Britain and their comments invited. Subject to considerations of space and CCC style, these comments will be published as submited. 相似文献
39.
测定27例肾腺癌的DNA含量,并联系肿瘤的分级等部分形态学指标,对透明细胞型和颗粒细胞型肿瘤进行比较分析。发现:透明细胞型肾腺癌的分化一般较好,DNA以二倍体为主,预后相对较好;而颗粒细胞型肾腺癌的分化较差,DNA以非二倍体为主,其预后较差。 相似文献
40.