首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18501篇
  免费   1697篇
  国内免费   1312篇
耳鼻咽喉   35篇
儿科学   136篇
妇产科学   269篇
基础医学   2204篇
口腔科学   39篇
临床医学   1406篇
内科学   4818篇
皮肤病学   56篇
神经病学   53篇
特种医学   657篇
外国民族医学   19篇
外科学   3844篇
综合类   2036篇
现状与发展   2篇
预防医学   337篇
眼科学   41篇
药学   799篇
  7篇
中国医学   134篇
肿瘤学   4618篇
  2024年   72篇
  2023年   383篇
  2022年   932篇
  2021年   1070篇
  2020年   805篇
  2019年   721篇
  2018年   655篇
  2017年   579篇
  2016年   853篇
  2015年   856篇
  2014年   1457篇
  2013年   1091篇
  2012年   1014篇
  2011年   1129篇
  2010年   884篇
  2009年   950篇
  2008年   991篇
  2007年   1058篇
  2006年   880篇
  2005年   734篇
  2004年   535篇
  2003年   555篇
  2002年   448篇
  2001年   327篇
  2000年   294篇
  1999年   262篇
  1998年   235篇
  1997年   215篇
  1996年   191篇
  1995年   155篇
  1994年   149篇
  1993年   125篇
  1992年   99篇
  1991年   104篇
  1990年   77篇
  1989年   83篇
  1988年   77篇
  1987年   52篇
  1986年   55篇
  1985年   51篇
  1984年   43篇
  1983年   38篇
  1982年   30篇
  1981年   38篇
  1980年   42篇
  1979年   25篇
  1978年   23篇
  1977年   17篇
  1976年   20篇
  1973年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
We report a case of stage IV ovarian clear cell adenocarcinoma (OCCA) in a 72-year-old woman who was treated postoperatively with etoposide combined with cisplatin (EP). The patient exhibited bulky intrapelvic and para-aortic lymph nodes with metastases to the cervical lymph nodes. The primary lesion was resected and, postoperatively, she received one course of combination chemotherapy consisting of cyclophosphamide, 500 mg/m2; doxorubicin, 50 mg/m2; and cisplatin, 70mg/m2 (CAP), followed by six courses of combination chemotherapy consisting of etoposide, 80mg/m2 days 1 through 5 and cisplatin, 70 mg/m2 on day 5 every 4 weeks. After five courses of EP, the lymph node metastases had virtually disappeared. The patient is now disease-free 21 months after the initial surgery. These findings suggest that EP may be useful in treating OCCA.  相似文献   
82.
目的建立N一甲基一N’一硝基一N一亚硝基胍(N-methy1-N’-nitro-N-nitrosoguanidine,MNNG)诱发大鼠腺胃癌模型并观察p53,ras基因的表达。方法给Wistar大鼠饮用MNNG水溶液(终浓度为80μg/ml),用ABC法检测P53和P21蛋白的表达。结果MNNG成功地诱发出了胃癌、胃腺瘤、胃息肉、胃粘膜不典型增生和历上皮化生等病变。胃癌肝转移2例,淋巴结转移1例。P53蛋白在肠化及不典型增生皆阴性,胃癌阳性率为50%;P21蛋白在肠化及不典型增生中阳性率为44%,在癌组织中为23%。结论MNNG能诱发大鼠脾胃癌等病变,P53基因突变在胃癌发生发展过程中起一定作用,而ras基因激活是一个早期现象。  相似文献   
83.
通过体内实验进一步证实rhPRL对机体免疫功能的调节作用,以及用于过继细胞免疫治疗的可能性。我们选用CB17 SCID纯系小鼠,腹腔注入人结肠腺癌细胞(HT29),2小时后腹腔注入尼龙毛纯化的人淋巴细胞(T/NK细胞),同时开始进行rhPRL治疗,并设HBSS对照和rhIL-2治疗对照组。结果表明,rhPRL在体内外均无直接抗癌效应,反而可促进肿瘤生长。当SCID荷瘤鼠同时移植入人的T/NK细胞时出rhPRL可明显提高T/NK细胞的抗癌效果,生存期明显延长(P<0.05)。平均生存期由70.4天延至112.1天,在对照组全部死亡时(d105),rhPRL治疗组有60%存活,且在实验终止时(>160天)仍有40%存活。分析其抗癌机理发现,rhPRL体外可直接促进人T/NK细胞增殖,其分泌上清可抑制肿瘤生长,同时发现人T/NK细胞与HT29共育4小时中rhPRL亦可直接促进杀伤活性。  相似文献   
84.
本室以往的研究表明,用腺病毒作为载体将大肠杆菌胞嘧啶脱氨酶(CD)基因与小鼠淋巴细胞趋化因子(Itn)基因联合体内转染,具有显著的抗肿瘤效应.本文对其免疫机理进行了进一步研究,发现CT26结肠腺癌细胞体外经过CD/Ltn基因转染并给予前体药物5-FC后,CT26结肠腺癌细胞表达CD80和CD54分子明显增加,提示经CD自杀基因和Ltn基因联转移后,肿瘤细胞免疫原性增加.荷瘤小鼠体内经联合治疗后,小鼠脾细胞分泌IL-2和IFN-γ明显增加.体内用抗CD4、CD8抗体阻断实验研究结果的表明,联合应用自杀基因和Ltn基因治疗主要通过诱导CD8~ T细胞发挥抗肿瘤作用.  相似文献   
85.
目的 探讨KAI1/CD82蛋白在胃腺癌组织中表达及其与胃癌生物学行为的关系。方法应用免疫组织化学技术S-P法检测68例胃腺癌组织中KAI1/CD82蛋白的表达,以20例非肿瘤性胃黏膜组织作对照。对随访14个月~13年的35例做生存分析。结果 68例胃腺癌组织KAI1/CD82蛋白阳性表达率为26、5%(18/68),对照组胃黏膜组织阳性表达率95.0%(19/20);高/中分化胃腺癌KAI1/CD82蛋白阳性表达率较低分化者为高,分别为41.4%(12/29)、15.4%(6/39),P〈0.05;无淋巴结转移胃腺癌的KAI1/CD82蛋白阳性表达率较有淋巴结转移者为高,分别为45.5%(10/22)、5.3%(8/46),P〈0.05;侵及黏膜及黏膜下层、肌层和浆膜层胃腺癌KAI1/CD82蛋白阳性表达率分别为66、7%(4/6)、34.8%(8/23)、15.4%(6/39),P〈0.05。KAI1/CD82蛋白在Ⅰ~Ⅱ期胃腺癌阳性表达率为37.0%(17/46),在Ⅲ~Ⅳ期胃腺癌中阳性表达率为13.6%(1/22),P〈0.05。KAI1/CD82蛋白阳性患者术后1、3、5、7、10年生存率分别为100.0%(7/7)、85.7%(6/7)、57.1%(4/7)、42.9%(3/7)和28.6%(2/7),而KAI1/CD82阴性患者术后生存率分别为89、3%(25/28)、42、9%(12/28)、14.3%(14/28)、7.1%(2/28)和3、6%(1/28)。KAI1/CD82蛋白阳性患者术后1、3、5、7和10年生存率比KAI1/CD82阴性患者术后1、3、5、7和10年生存率显著提高,P〈0.05。结论 KAI1/CD82蛋白在胃腺癌的表达与肿瘤浸润深度、分化程度、临床分期及淋巴结转移有关,与患者性别、年龄无关。检测KAI1/CD82蛋白有助于临床评估病情,判断预后。  相似文献   
86.
探讨卵巢透明细胞癌的临床、病理特点及预后,回顾性分析我院1982年1月~2001年12月70例原发性卵巢透明细胞癌患者临床资料,对其临床特点与治疗情况进行总结并对预后进行随访,总结其发病规律及临床特点。卵巢透明细胞癌多以腹痛、腹胀和盆腔包块为主要症状(占就诊者80%),70例患者全部进行手术,满意肿瘤细胞减灭术5年生存率(61.5%)与不满意肿瘤细胞减灭术5年生存率(7.69%)差异有统计学意义。术后病理组织证实单纯透明细胞癌42例,透明细胞癌合并其他上皮性癌28例,合并子宫内膜异位症19例。共65例于术后进行了PT、PAC等化疗。在不同方案、不同疗程比较中,发现PT方案、6个疗程以上化疗组有较高的5年生存率,与PAC组、其他化疗方案组差异有统计学意义,P=0.005。卵巢透明细胞癌临床特点不同于其他的卵巢上皮恶性肿瘤,是上皮癌的一种特殊组织类型,其临床分期早,化疗不敏感,即使是早期亦易复发,预后较差,应引起重视。手术尽量行理想的肿瘤细胞减灭术,术后行6个疗程以上的PT方案化疗,可望改善疗效。  相似文献   
87.
Between 1989 and 2002, 28 patients with locally advanced cervical adenocarcinoma (bulky IB-IIIB) were recruited for a pilot study aimed at evaluation of the effectiveness of neoadjuvant chemotherapy with cisplatin, aclacinomycin-A, and mitomycin-C (PAM), followed by radical surgery. This regimen was administrated intra-arterially or intravenously. In addition to patients treated with PAM, we retrospectively analyzed the prognoses of 26 patients in stage I and II, who had been treated between 1975 and 1981 with radical surgery with/without radiation therapy. Twenty-eight patients received PAM therapy as neoadjuvant chemotherapy, and 75.0% of the 16 intra-arterially infused patients showed a response, as did 66.7% of the 12 intravenously infused patients. There was a significant difference in the 5-year prognosis of stage II (PAM group, 72.9%; without-PAM group, 36.4%). The results suggest that, as the free space in the parametrium is widened by neoadjuvant chemotherapy with PAM, it is possible that the tumor could be completely resected by radical hysterectomy. Thus, neoadjuvant chemotherapy with PAM is expected to improve the survival rate of patients with advanced cervical adenocarcinoma by the preliminary study. However, the survival rates of stage II with lymph node metastasis in the without-PAM group seem low, and we must also consider that the various technologies to evaluate and treat the cervical adenocarcinomas, e.g. computed tomography, magnetic resonance imaging, and surgical equipments, had improved during 1989-2002 than was the scenario during 1975-1981, and these improvements contributed to better prognosis. A prospective-randomized study is needed to assess the value of this approach compared with standard management.  相似文献   
88.
PTEN, a tumor suppressor gene, appears to negatively control the phosphoinositide 3-kinase signaling pathway for regulation of cell proliferation and cell survival. Somatic PTEN mutations are involved in a variety of tumors, including endometrial carcinomas, where PTEN expression is diminished. We examined expression of PTEN in a series of cervical adenocarcinomas and precursors, using tissue microarray (TMA) technology. TMA blocks were constructed using paraffin-embedded, formalin-fixed tissues from 273 samples derived from 16 normal cervical biopsies, 119 cases of invasive adenocarcinoma, and 20 high-grade cervical glandular intraepithelial neoplasia (CGIN). Fresh 3-mum sections were cut and immunostained with PTEN, and expression was correlated with clinicopathologic variables, including histologic subtypes of adenocarcinoma. In 137 patients, PTEN expression was positive in 121 (88%). The intensity and distribution of PTEN staining in the tumor tissue were more heterogeneous than those observed in the normal tissues. There were no significant differences in distribution or intensity of PTEN expression between adenocarcinoma in situ and subtypes of invasive adenocarcinoma. Our findings show that unlike the case in most endometrial carcinomas, PTEN expression is retained during the process of carcinogenesis in the glandular cervix. There is, however, evidence of altered distribution and intensity of PTEN expression in cervical adenocarcinoma cells.  相似文献   
89.
The objective of this study was to investigate the efficacy of treatment strategies in patients with adenocarcinoma (AC) of the cervix and compare it with those with squamous cell carcinoma (SCC) of the cervix. Women with FIGO (1994) stage IB1 AC, especially pathologic tumor size of 2-4 cm, treated with class III hysterectomy, were compared with those with SCC treated with comparable strategy in a case-controlled study. Eighty patients (20 cases, 60 controls) were analyzed. Lymphvascular space invasion (P = 0.01) and lymph node metastasis (P = 0.07) were more frequent in patients with SCC than in those with AC. However, there was no significant difference in depth of stromal invasion (P = 0.51) and invasion of the parametrium (P = 0.44) between two groups. And there was also no statistically significant difference in disease-free survival (P = 0.86) and overall survival (P = 0.89) between two groups. Primary radical surgery followed by adjuvant therapy, same as for SCC, would be acceptable for AC with pathologic tumor size of 2-4 cm. Although it was difficult to determine whether AC recurred more systemically, more effective treatment strategies than those currently available for AC should be considered to reduce the systemic recurrence.  相似文献   
90.
熊玮  钱桂生  黄桂君 《重庆医学》2006,35(17):1577-1579
目的 建立氯氨顺铂诱导肺腺癌耐药细胞株A549/CDDP。分析A549/CDDP生物学特性及染色体核型,为肺腺癌的治疗提供实验依据。方法 采用氯氨顺铂(Cis—diaminodichloroplatin,CDDP)大剂量冲击加逐步诱导法建立肺腺癌耐药细胞株A549/CDDP,MTT法检测细胞耐药指数.生物发光法测定细胞能量代谢,流式细胞仪测试细胞周期,染色体G显带技术和光谱核型分析(spectral karyotyping,SKY)技术分析染色体变化。结果 MTT检测结果表明。A549/CDDP对7种不同的化疗药物表现了不同的耐药性,其ATP、ADP、AMP含量显著降低,细胞周期无明显变化。G显带结果表明A549/CDDP染色体为亚三倍体,SKY分析出现数条衍生染色体。结论 CDDP可以成功诱导肺腺癌耐药细胞株A549/CDDP,A549/CDDP衍生染色体可能与肺腺癌耐药有关。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号