全文获取类型
收费全文 | 497篇 |
免费 | 17篇 |
国内免费 | 29篇 |
专业分类
儿科学 | 6篇 |
妇产科学 | 16篇 |
基础医学 | 103篇 |
口腔科学 | 4篇 |
临床医学 | 40篇 |
内科学 | 93篇 |
皮肤病学 | 23篇 |
神经病学 | 5篇 |
特种医学 | 5篇 |
外国民族医学 | 1篇 |
外科学 | 53篇 |
综合类 | 86篇 |
预防医学 | 5篇 |
眼科学 | 1篇 |
药学 | 13篇 |
中国医学 | 18篇 |
肿瘤学 | 71篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 14篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 34篇 |
2010年 | 37篇 |
2009年 | 26篇 |
2008年 | 36篇 |
2007年 | 34篇 |
2006年 | 49篇 |
2005年 | 46篇 |
2004年 | 35篇 |
2003年 | 22篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 18篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 9篇 |
排序方式: 共有543条查询结果,搜索用时 15 毫秒
1.
胃肠道间质瘤的临床病理研究 总被引:6,自引:0,他引:6
目的:探讨胃肠道间质瘤(gastrointestinal stromal tumor,GIST)的临床病理特点。方法:对55例GIST的病例进行分析,并对其进行CD117、CD34、S-100、SMA、vimenfin、desmin、NF共7种免疫组化分析。结果:肿瘤的发生部位:胃38例(69%),小肠10例(18%),其他部位7例(13%)。肿瘤直径0.4—40cm(平均6.7cm)。肿瘤最大直径≥5cm、核分裂像数≥5/50 HPF及有溃疡形成3项在良性与恶性之间差异有显著意义。免疫组化的阳性表达结果为:CD117 39例(71%)、CD34 45例(82%)、S-100 19例(35%)、SMA 12例(22%)、vimentin 32例(58%)、desmin 6例(11%)、NF2/4(50%)。13例良性GIST患者全部存活,42例恶性及潜在恶性GIST中有4例发生转移,13例死亡。结论:(1)GIST好发于中老年人,无明显性别差异。(2)其主要恶性指标为:肿瘤最大径≥5cm、核分裂像≥5/50 HPF和有溃疡形成。(3)光镜下很难将平滑肌性肿瘤及神经源性肿瘤与GIST相鉴别。 相似文献
2.
Cajal间质细胞在先天性巨结肠和巨结肠同源病结肠中的分布研究 总被引:3,自引:0,他引:3
目的研究先天性巨结肠(Hirschsprung’s disease,HD)和巨结肠同源病(allied Hirschsprung’s disease,AHD)肠壁内Cajal间质细胞(interstitial cells of Cajal,ICCs)的分布状态,探讨HD和AHD的发病机制。方法选择确诊为HD和AHD的患者各20例,取巨结肠根治术吻合口远端的全层肠壁作为实验组,另取16例正常结肠标本作为对照组。用鼠抗人c—kit单克隆抗体(CD117)标记ICCs,Image Pro-Plus图像分析系统检测ICCs。结果对照组中大量ICCs分布在肌间神经丛周围和环纵肌层内,ICCs包绕神经丛周围,肌层间ICCs连续分布;HD组远端肠管中肌层间和各肌层内ICCs明显减少甚至缺如,与对照组比较差异有统计学意义,P〈0.01;AHD组远端肠管中神经丛大小不一,ICCs分布差异大,大多数神经丛区ICCs减少,环肌层内ICCs明显减少,与AHD组和对照组比较差异有统计学意义,P〈0.01。HD组远端结肠中ICCs减少比AHD组显著,差异有统计学意义,P〈0.01。结论HD、AHD病变肠管中除了神经节细胞的异常外,同时存在ICCs异常;ICCs在HD和AHD的分布不同可能与两者临床症状差异有关;肠管中ICCs数量可能与临床症状及预后有一定关系。 相似文献
3.
Perivascular epithelioid cell tumor of the uterus: immunohistochemical, ultrastructural and molecular study 总被引:1,自引:0,他引:1
A case of perivascular epithelioid cell tumor of the uterus is reported, occurring in a 32-year-old woman. The tumor (8.0 cm in dimension) showed exophytic growth from the outer half of the myometrium. Histopathologically, the tumor was composed of thick blood vessels and perivascular epithelioid cells. The neoplastic cells were strongly immunoreactive for HMB45 antigen, CD117 (c-kit), vimentin and the progesterone receptor, but completely negative for S-100 protein, smooth muscle actin, desmin, CD34, the estrogen receptor and p16. The Ki-67 labeling index was low (1.25%). Ultrastructurally, the neoplastic cells had numerous premelanosomes with some glycogen deposits. Single-stranded DNA conformational polymorphism of p53 and methylation-specific polymerase chain reaction of p16 revealed negative results. Definite melanosomes on electron microscopic analysis and coexpression of HMB45 antigen and stem cell factor receptor (CD117) may provide the clue to understanding perivascular epithelioid cell tumor because angiomyolipoma also coexpresses HMB45 antigen and CD117. 相似文献
4.
Halder Seki Weerasinghe Kawamura Watanabe Abo 《Clinical and experimental immunology》1998,114(3):434-447
We previously reported that c-kit+ stem cells which give rise to extrathymic T cells are present in the liver of adult mice. Further characterization of extrathymic T cells in the liver of adult mice is conducted here. When mice with a liver shield were lethally (9.5 Gy) irradiated, all mice survived. All tested organs showed a distribution pattern of hepatic lymphocytes on day 7. The distribution pattern in the liver was characterized by an abundance of NK (CD3? IL-2Rβ+) and extrathymic T cells (CD3int IL-2Rβ+) before and after irradiation. To determine their function, post-irradiation allogeneic bone marrow transplantation (BMT) was performed in mice with or without a liver shield. Allogeneic BM cells were rejected in mice with a liver shield and specific activation of CD8+ CD3int IL-2Rβ+ cells was induced. At that time, potent cytotoxicity of liver mononuclear cells (MNC) against allogeneic thymocytes was induced. Both NK1.1+ and NK1.1? subsets of CD3int cells expanded in these mice. An in vivo elimination experiment of the subsets indicated that the NK1.1+ subset of CD3int cells (i.e. NK T cells) was much more associated with the rejection of allogeneic BM cells. However, even after the elimination of NK T cells, allogeneic BM cells were rejected. In this case, granulocytes expanded in parallel with NK1.1? subsets. Granulocytes may also be associated with the rejection of allogeneic BM cells. These results suggest that the liver is an important haematopoietic organ even in adult life. 相似文献
5.
胃肠道间质瘤与酪氨酸激酶抑制剂 总被引:2,自引:0,他引:2
胃肠道间质瘤 (GISTs)是发生于消化道的一种非神经源性、非平滑肌源性的独立疾病。在GISTs中存在不同位点的c kit功能获得性突变 ,激活其产物KIT的酪氨酸激酶活性 ,从而活化多条信号转导通路 ,诱导细胞增殖与恶变。STI5 71是人工合成的一种酪氨酸激酶抑制剂 ,抑制激酶和底物的磷酸化。STI5 71治疗GISTs的Ⅰ ,Ⅱ期临床试验疗效显著 ,且耐受性较好 相似文献
6.
Tohru Tsujimura 《Pathology international》1996,46(12):933-938
The c-kit gene is allelic with the dominant spotting ( W ) locus on mouse chromosome 5 and encodes a receptor tyrosine kinase. The llgand for c-klt receptor is stem cell factor (SCF), which is the principal growth factor for mast cells. The loss-of-function mutations of c-kit receptor affect the development of mast cells, thereby resulting in a depletion of mast cells. The abundant expression of c-ktt receptor is indispensable for the survival of mast cells. In addition, the galn-of-function mutations of c-kit receptor were found in several tumor mast cell lines. When these galn-of-function mutations were introduced to cells of murine interleukin (IL)-3-dependent cell lines, the expression of c-kit receptor with constitutive tyrosine kinase activity not only abrogated the IL-3 requirement of the cells, but also caused them to become tumorlgenic in nude athymic mice. The gain-of-function mutations of c-kit receptor appear to result in the malignant transformation of mast cells. Taken together, the signals from the c-ktt receptor are essential for the development, survival, and malignant transformation of mast cells. 相似文献
7.
c-kit在血液病中的表达 总被引:1,自引:0,他引:1
目的 :探讨原癌基因c -kit在血液病中表达的情况。方法 :用Ficoll分离液分离 ,收集骨髓单个核细胞。c -kit的表达采用RT -PCR法。结果 :在不同血液病中c -kit的表达情况不一 ,在急性髓细胞性白血病 (AML)为 5 7.8% ,急性淋巴细胞性白血病 (ALL)为 8.3 % ,骨髓增生异常综合征 (MDS)为 40 %。结论 :c -kit主要在AML中表达 ,提示c -kit表达是粒细胞的一个特异性标志。 相似文献
8.
目的 了解骨髓增生异常综合征 (MDS)骨髓单个核细胞c kit受体的表达与功能。方法 采用免疫荧光方法测定c kit受体蛋白 (CD117)的表达 ;逆转录 聚合酶链反应方法测定c kitmRNA的表达 ;细胞培养检测c kit受体的功能。结果 CD117表达率正常人为 3 0 4 %± 1 4 9% ,MDS患者为 8 58%± 5 2 8% ,两者差异有显著性 (P <0 0 5) ;RA患者为 5 12 %± 2 13% ) ,RAEB RAEB t患者为 10 0 1%± 5 0 7% ,两者差异有显著性 (P <0 0 5) ;MDS继发白血病患者为 32 4 3%± 18 16 %。MDS患者c kit基因mRNA表达与CD117表达相一致。正常骨髓单个核细胞体外半固体培养 ,在加入造血干细胞因子、白细胞介素 3、红细胞生成素 (SCF IL 3 Epo)后形成的粒 巨噬细胞集落 (CFU GM)较仅加入IL 3 Epo显著增多 (P <0 0 5) ,红系爆式集落 (BFU E)数量极显著增多 ,且BFU E体积显著增大(P <0 0 1)。MDS患者在上述相同条件下CFU GM数量无明显变化 (P >0 0 5) ,与正常对照比较 ,CFU GM和BFU E数量均显著减少 (P <0 0 5)。结论 MDS患者骨髓单个核细胞CD117表达明显高于正常对照 ,且与病情进展相关 ;c kitmRNA表达与CD117表达相一致 ;MDS患者骨髓单个核细胞体外培养时 ,SCF协同IL 3、Epo促进造血干 祖细胞增殖分化能力较正常对照明 相似文献
9.
Hozumi Katsuto; Kobori Akiko; Sato Takehito; Nishimura Takashi; Habu Sonoko 《International immunology》1996,8(10):1473-1481
10.