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   39213篇
  免费   5546篇
  国内免费   878篇
耳鼻咽喉   58篇
儿科学   418篇
妇产科学   345篇
基础医学   4302篇
口腔科学   444篇
临床医学   3394篇
内科学   1111篇
皮肤病学   149篇
神经病学   317篇
特种医学   2210篇
外国民族医学   74篇
外科学   5195篇
综合类   5217篇
现状与发展   6篇
一般理论   1篇
预防医学   1890篇
眼科学   67篇
药学   2118篇
  31篇
中国医学   668篇
肿瘤学   17622篇
  2024年   112篇
  2023年   642篇
  2022年   1312篇
  2021年   2042篇
  2020年   1892篇
  2019年   1637篇
  2018年   1505篇
  2017年   1548篇
  2016年   1733篇
  2015年   2086篇
  2014年   2616篇
  2013年   2832篇
  2012年   2237篇
  2011年   2379篇
  2010年   1815篇
  2009年   1769篇
  2008年   1732篇
  2007年   1852篇
  2006年   1877篇
  2005年   1700篇
  2004年   1401篇
  2003年   1340篇
  2002年   1087篇
  2001年   966篇
  2000年   765篇
  1999年   676篇
  1998年   540篇
  1997年   515篇
  1996年   420篇
  1995年   363篇
  1994年   272篇
  1993年   232篇
  1992年   212篇
  1991年   200篇
  1990年   143篇
  1989年   128篇
  1988年   130篇
  1987年   115篇
  1986年   108篇
  1985年   144篇
  1984年   106篇
  1983年   74篇
  1982年   86篇
  1981年   84篇
  1980年   43篇
  1979年   48篇
  1978年   36篇
  1977年   28篇
  1976年   26篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
71.
 

Aims:


The purpose of this study is to examine the relationship between immunohistochemical localization of cathepsin D (CD), proliferating cell nuclear antigen (PCNA) and epidermal growth factor receptor (EGF-R) in 65 cases of breast carcinoma in Japanese women and traditional prognostic factors such as histological grade, lymph node status, mitotic rate and clinical stage, in order to possibly identify some indicator(s) that may be specifically associated with prognosis.  

Methods and results:


Serial sections of 5-μm thick were cut from the archival formalin-fixed, paraffin-embedded tissue blocks, and processed for CD, PCNA and EGF-R immunostaining. The results were analysed by computer-based image analysis system. All samples showed a positive immunoreaction for cathepsin D in both the parenchyma and stroma. However, the staining area and intensity varied from cell to cell in the parenchyma and stroma as well as among samples. Subsequently, the evaluation of immunostaining for CD was separately performed in both the parenchyma and stroma (CDpar and CDstr, respectively) and the combination of both components (CDtotal). PCNA and EGF-R showed positive immunostaining almost exclusively in the parenchymal component of the carcinoma tissue specimens. CDtotal significantly correlated with the histological grade, PCNA index (PI), mitotic rate (MR), EGF-R and lymph node metastasis. Significant correlation was also demonstrated between CDpar and the histological grade, EGF-R and lymph node metastasis, or between CDstr and MR, EGF-R and lymph node metastasis. EGF-R correlated highly with the histological grade, MR score, lymph node metastases and recurrence-free survival.  

Conclusions:


Both the CD parameters and EGF-R are valuable indicators for predicting the biological behaviour of human breast carcinoma.  相似文献   
72.
 Immunocytochemically detectable MT and p53 have been found more commonly in comedo DCIS of the breast with high-grade cytology. The aim of this study is to confirm these findings and to investigate the relationship between MT and p53 in a single large series of cases of DCIS of the breast. To this end, 127 cases of DCIS were classified histologically according to architecture, cytonuclear differentiation (grade), presence and extent of intraduct necrosis, and using the Van Nuys system. Sections were immunostained for p53 and MT (E9) using established techniques, and the extent and intensity of staining were assessed semi-quantitively. The results confirmed that there was generally more MT and p53 positivity in poorly differentiated (grade 3) DCIS with extensive necrosis and that MT expression was greater in grade 2 lesions than p53 expression. However, overall there was no statistically significant correlation between p53 and MT staining. The results indicate that MT and p53 overexpression may arise from independent mechanisms in early breast neoplasia. Received: 3 July 1996 / Accepted: 5 November 1996  相似文献   
73.
在欧美,乳腺肿块针吸细胞学诊断于70年代就已得到了成功的应用。近年来国内的一些研究也证实其实用价值。为了进一步提高乳腺细胞学诊断水平,现将我院针吸细胞学诊断乳腺肿块281例中由病理证实的118例进行总结分析。1 材料与方法1.1 临床资料:1986年12月~1990年2月采用针吸细胞学检查诊断乳腺肿块281例,其中118例施行手术并获得病理组织学的证实。细胞学诊断以原始报告为准。女  相似文献   
74.
Abstract: Breast conservation surgery is an effective and safe treatment for many breast carcinomas. It may be possible to further limit the extent of resection (or expand the indication for breast conservation) by the application of preoperative chemotherapy and radiotherapy. We explored the feasibility of this in a pilot study.
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored.  相似文献   
75.
Digital movment analysis (DMA) is a new instrumental approach to assessing oral tardive dyskinesia (TD) by means of digital image processing of a video signal, tracking five paper dots placed around the patient's mouth. A total of 40 schizophrenic patients, 30 with and 10 without TD, were examined twice (with a 3-month interval) with this new device. The patients were further examined with two TD rating scales: the St. Hans Rating Scale for extrapyramidal syndromes (SHRS) and the Abnormal Involuntary Movement Scale (AIMS).The schizophrenic patients accepted the instrumental assessment without any anxiety or resistance. The internal relibility of the apparatus was high, with correlation coefficients of 0.80–0.99. The DMA TD values correlated with the SHRS and AIMS scores with correlation coefficients of 0.48–0.73 indicating an acceptable, although not strong, concurrent validity. Fluctuations occurred from the first to the second examination independent of medication. For these fluctuations no correlation was found between DMA values and rating scores. Finally, the DMA device was able to detect perioral tremor as a sign of parkinsonism.It has been concluded that DMA is a useful supplement to classical TD rating, although further validity evaluation is warranted.  相似文献   
76.
Summary Thirty-two eligible patients with advanced metastatic breast cancer who had received no more than 1 prior chemotherapy regimen for metastatic disease (16 had received prior doxorubicin) were treated with piroxantrone at a dose of 120 mg/m2 intravenously every 21 days. In the twenty-seven patients evaluable for response, two partial responses were seen. Toxicities observed were primarily hematologic with grade 3 or greater granulocytopenia occurring in 34% of the patients. One patient developed symptomatic congestive heart failure at a total cumulative dose of 960 mg/m2. We conclude that piroxantrone given at this dose and schedule has minimal activity in patients with metastatic breast cancer.  相似文献   
77.
Summary Based upon the hypothesis that dipyridamole would potentiate the cytotoxicity of mitoxantrone and the combination of 5-fluorouracil (5-FU) and leukovorin, we performed a phase I/II trial of the combination of dipyridamole, 5-FU, leukovorin, and mitoxantrone in patients with metastatic breast cancer. The dose of dipyridamole was fixed at 175 mg/m2 by mouth every 6 h (700 mg/m2/day), based upon a previous phase I trial of oral dipyridamole with 5-FU and leukovorin. Dipyridamole therapy began 24 h prior to the first dose of chemotherapy and continued until 24 h after the last dose of chemotherapy for each course of treatment. At the initial dose level, leukovorin 200 mg/m2 was given intravenously immediately prior to 5-FU 375 mg/ m2 intravenously on days 1–5. Mitoxantrone 6 mg/m2 was given as a single dose on day 3. Unacceptable toxicity was observed at this dose level, leading to successive dose decrements rather than dose increments. The maximum tolerated dose was leukovorin 200 mg/m2 days 1–2, 5-FU 375 mg/m2 days 1–2, mitoxantrone 6 mg/m2 on day 2, and dipyridamole 175 mg/m2 every 6 h on days 0–3. Two responses were produced in 15 patients. This regimen is not recommended for further investigation in the treatment of breast cancer.  相似文献   
78.
邱学华  黄裕新 《营养学报》1993,15(3):345-347
<正> 至今有关母乳中胃肠激素研究较少,国内未见报道。我们应用放射免疫法测定了45例正常产妇血及乳汁中胃动素和胃泌素浓度,以期为普及母乳喂养提供新依据。 1 材料和方法 1.1 研究对象 1992年4~7月,选我院单胎妊娠自然分娩的产妇45例,平均25.51岁(22~28岁);胎龄39.60周(36~41周);产程12.35小时(5.20~17.35小时);平均出血量0.17L(0.08~0.35L);  相似文献   
79.
A 31-year-old married man with normal male characteristics requested hormonal treatment to enlarge his breasts and nipples. He did not feel himself to be homosexual or transsexual but considered himself incomplete without female breasts and nipples. Petting of his nipples resulted in sexual excitement and he presumed that feminization of his breasts would improve this function. His wife supported his wish. After treatment with 0.150 mg ethinylestradiol per day for 9 months, moderate breast enlargement occurred and the nipples became the size of normal female nipples. One year afterwards he remained satisfied with his female-type breasts and in particular with the increased sexual function of his nipples. Stimulation of his nipples resulted in erection and ejaculation.  相似文献   
80.
Granular cell tumors (GCT) are rare neoplasms, and only 173 cases of benign GCT of the breast have been documented. We report herein the cases of two patients with this tumor and discuss the methods of diagnosis and treatment. The first patient was a 60-year-old woman who presented with a firm ill-defined mass in her left breast. Mammography showed a dense shadow with spicula and skin thickness, and ultrasonography revealed a hypoechoic mass with an irregular border. Radical mastectomy was performed under the wrong preoperative diagnosis of breast cancer. The second patient was a 31-year-old woman who presented with an elastic-hard mass in her left breast. Mammography showed a well-demarcated dense mass, and ultrasonography revealed a well-defined hypoechoic mass with a large depth-width ratio. Fine-needle aspiration cytology (FNAC) showed a large number of histiocytic cells with abundant granular cytoplasm. An excisional biopsy was performed, and histological examination confirmed a diagnosis of GCT. GCT is benign, but often misdiagnosed as breast cancer both clinically and radiologically. Therefore, histological examination is essential for making a correct diagnosis, while FNAC is also useful. Local resection is still the treatment of choice, and surgeons should do their utmost to avoid performing needless radical mastectomy.  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