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   9525篇
  免费   445篇
  国内免费   45篇
耳鼻咽喉   81篇
儿科学   151篇
妇产科学   78篇
基础医学   1494篇
口腔科学   272篇
临床医学   856篇
内科学   1619篇
皮肤病学   149篇
神经病学   1108篇
特种医学   870篇
外科学   1347篇
综合类   41篇
一般理论   3篇
预防医学   316篇
眼科学   243篇
药学   679篇
中国医学   24篇
肿瘤学   684篇
  2024年   9篇
  2023年   35篇
  2022年   82篇
  2021年   148篇
  2020年   105篇
  2019年   138篇
  2018年   165篇
  2017年   134篇
  2016年   193篇
  2015年   251篇
  2014年   303篇
  2013年   369篇
  2012年   584篇
  2011年   637篇
  2010年   412篇
  2009年   407篇
  2008年   639篇
  2007年   684篇
  2006年   700篇
  2005年   720篇
  2004年   646篇
  2003年   643篇
  2002年   618篇
  2001年   126篇
  2000年   108篇
  1999年   125篇
  1998年   123篇
  1997年   92篇
  1996年   88篇
  1995年   84篇
  1994年   82篇
  1993年   60篇
  1992年   41篇
  1991年   42篇
  1990年   30篇
  1989年   31篇
  1988年   28篇
  1987年   36篇
  1986年   21篇
  1985年   18篇
  1984年   25篇
  1983年   25篇
  1982年   23篇
  1981年   26篇
  1980年   16篇
  1979年   25篇
  1978年   20篇
  1977年   17篇
  1976年   13篇
  1975年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
PURPOSE: To evaluate treatment outcome of 3D conformal high dose rate (HDR) brachytherapy and external beam irradiation (EBRT) combined with temporary androgen deprivation for patients with localized prostate cancer. PATIENTS AND METHODS: Between January 1997 and September 1999 we treated 102 patients with stage T1-3 N0 M0 prostate cancer. Stage T1-2 was found in 71, T3 in 31 patients. Median pretreatment PSA level was 15.3 ng/ml. After ultrasound-guided transrectal implantation of four afterloading needles, CT based 3D brachytherapy planning was performed. All patients received four HDR implants using a reference dose per implant of 5 or 7Gy. Time between each implant was 14 days. After brachytherapy EBRT followed up to 39.6 or 45.0 Gy. All patients received temporary androgen deprivation, starting 2-19 months before brachytherapy, ending 3 months after EBRT. RESULTS: Median follow-up was 2.6 years (range 2.0-4.1 years). Actuarial biochemical control rate was 87% at 2 years and 82% at 3 years. In 14 patients we noted biochemical failure, in five patients clinical failure. Overall survival was 90%, disease specific survival 98.0% at 3 years. Acute grade 3 toxicity occurred in 4%, late grade 3 toxicity in 5%. One patient developed a prostatourethral-rectal fistula as late grade 4 toxicity. The conformal quality of 300 HDR implants was analyzed using dose volume histograms. CONCLUSIONS: 3D conformal HDR brachytherapy and EBRT combined with temporary androgen deprivation is an effective treatment modality for prostate cancer with minimal associated toxicity and encouraging biochemical control rates after a median follow-up of 2.6 years.  相似文献   
83.
PURPOSE: The role of unrelated allogeneic stem-cell transplantation in acute lymphoblastic leukemia (ALL) patients is still not clear, and only limited data are available from the literature. We analyzed factors affecting clinical outcome of ALL patients receiving a related or unrelated stem-cell graft from matched donors. PATIENTS AND METHODS: The total study population was 264 adult patients receiving a myeloablative allogeneic stem-cell transplant for ALL at nine bone marrow transplantation centers between 1990 and 2002. Of these, 221 patients receiving a matched related or unrelated graft were analyzed. One hundred forty-eight patients received transplantation in complete remission; 62 patients were in relapse; and 11 patients were refractory to chemotherapy before transplant. Fifty percent of patients received bone marrow, and 50% received peripheral blood stem cell from a human leukocyte antigen-identical related (n = 103), or matched unrelated (n = 118) donor. RESULTS: Disease-free survival (DFS) at 5 years was 28%, with 76 patients (34%) still alive (2.2 to 103 months post-transplantation), and 145 deceased (65 relapses, transplant-related mortality, 45%). We observed an advantage regarding DFS in favor of patients receiving transplantation during their first complete remission (CR) in comparison with patients receiving transplantation in or after second CR (P =.014) or who relapsed (P <.001). We observed a clear trend toward improved survival in favor of B-lineage ALL patients compared with T-lineage ALL patients (P =.052), and Philadelphia chromosome-positive patients had no poorer outcome than Philadelphia chromosome-negative patients. Total-body irradiation-based conditioning improved DFS in comparison with busulfan (P =.041). CONCLUSION: Myeloablative matched related or matched unrelated allogeneic hematopoietic stem-cell transplantation in ALL patients should be performed in first CR.  相似文献   
84.
PURPOSE: Imiquimod represents a synthetic local immune response modifier that has demonstrated efficacy in clearing basal cell carcinoma. Via interaction with Toll-like receptor 7 on immune cells, imiquimod induces local production of cytokines, such as interferon (IFN)-alpha. EXPERIMENTAL DESIGN: To more closely define and elucidate mechanisms leading to basal cell carcinoma clearance in vivo, we examined gene expression profiles of skin basal cell carcinoma before and after treatment with 5% imiquimod cream (Aldara) by using high-density oligonucleotide arrays. RESULTS: We show that imiquimod predominantly induces genes involved in different aspects of immune response. In addition to effects on immunity, imiquimod treatment modulates the expression of genes involved in the control of apoptosis and oncogenesis. Array data indicated that imiquimod treatment induces expression of opioid growth factor receptor, a molecule recently reported to be a target for antitumor antibody responses. Immunohistochemistry revealed in vivo up-regulation of opioid growth factor receptor protein on tumor and on infiltrating cells after treatment. By using basal cell carcinoma cell lines treated with IFN-alpha or imiquimod, we show that opioid growth factor receptor up-regulation is IFN-alpha-mediated, rather then directly imiquimod-mediated. By using tissue microarray containing 52 basal cell carcinomas, we demonstrate opioid growth factor receptor expression in almost half of the cases. Expression of opioid growth factor receptor correlated with a longer recurrence-free period in basal cell carcinoma that recurred after radiotherapy (Kaplan-Meier analysis, P = 0.041). CONCLUSIONS: In addition to its immunomodulatory and antiproliferative activity, opioid growth factor receptor seems to have a prognostic significance in basal cell carcinoma patients. Our data add to the growing list of basal cell carcinoma-associated tumor antigens.  相似文献   
85.
AIM: To report the complication rates of limb-salvage reconstruction in the pelvis. Detailed analyses about the type, treatment and outcome of post-operative complications, various reconstruction options are presented. METHODS: Factors that might influence the occurrence of complications were evaluated of 50 consecutive surgically treated patients. RESULTS: The mean follow-up was 57 months. Limb-salvage procedures were used in 42/50 patients, amputations in 8/50 patients. After limb-salvage procedures complications occurred in 32/42 patients, after hemipelvectomy in 6/8 patients. The 1 and 5-year overall survival rate was 92 and 68%, respectively. CONCLUSION: There is a high complication rate in reconstructive techniques using hemipelvic autografts and/or allografts. These procedures are appropriate only in well selected patients. The complication rates following endoprosthetic reconstruction are comparably low.  相似文献   
86.
AIMS: This study reports outcome, functional results and quality of life of 45 elderly patients with age over 70 after surgery for primary malignant bone and soft tissue tumours. METHODS: There were 24 primary malignant bone tumours and 21 soft tissue sarcomas. The most frequent diagnoses were: chondrosarcoma, malignant fibrous histiocytoma and liposarcoma. Local tumour resection with and without osteosynthesis, endoprostheses, and amputations had been performed for surgery. The patients were prospectively followed in a tumour register. RESULTS: Complication and revision rate, functional outcome using the Musculoskeletal Tumor Society score, 5-year survival rate, median survival time and quality of life according to the Life Satisfaction Index A and the global health and quality-of-life scale of the QLQ-C30 revealed results that are only slightly inferior to those reported in younger tumour patients. CONCLUSIONS: The results of this study generally justify even extensive tumour surgery in the elderly patient over 70 although outcomes are not quite as good as those reported for younger adults. However, especially in the old patient indications like general condition and comorbidity should be given due consideration before any decision is made on whether surgery should be performed and if so what surgical technique should be applied.  相似文献   
87.
88.
: To evaluate survival and patterns of recurrence in patients with primary central nervous system germinoma treated with radiation therapy.

: Data regarding 48 patients with histologically confirmed, primary central nervous system germinoma were reviewed. All had been operated on at the Mayo Clinic between the years 1935 and 1993. Thirty-two patients (67%) were treated since 1973. The study group included 39 males and 9 females, with a median age at diagnosis of 17 years (range, 6–42 years). Twelwe patients (25%) were treated with craniospinal axis irradiation, 11 (23%) received whole-brain irradiation without spinal axis irradiation, and 24 (50%) underwent partial-brain irradiation. Treatment volumes were unknown in one patient. The median dose to the primary tumor was 44.00 Gy (range, 7.44–59.40 Gy). The median follow-up was 5.5 years (range, 4 months to 37 years).

: Actuarial 5-year and 10-year survival for the entire study group of patients was 80%. There was a trend toward improved survival in patients treated after 1973 (introduction of computed tomography) with 5-year and 10-year survival of 91% vs. 63% in prior years (p = 0.07). For the group of 31 patients treated since 1973 with known treatment volumes, the spinal axis failure rate at 5 years was 49% for patients treated with partial brain fields (11 patients) vs. 0% for those having undergone whole brain (10 patients) or craniospinal axis (10 patients) irradiation (p = 0.007). The rate of brain failure was also significantly higher in patients receiving less than whole-brain irradiation; at 5 years, 45% of the patients treated with partial-brain fields had intracranial recurrence of disease compared to 6% of patients treated with craniospinal axis or whole-brain irradiation (p = 0.01). Among the 32 modern era patients, the rate of brain failure was higher in patients who received doses less than 40 Gy (median dose, 48.55 Gy; range, 30.60-59.40 Gy) to the primary tumor (5-year brain failure rate 52% vs. 11%, p = 0.002).

: The long-term survival of patients with histologically proven CNS germinoma treated with radiation is excellent. Whole-brain or craniospinal axis irradiation appears to result in fewer spine and brain failures than does partial-brain irradiation. Furthermore, the administration of doses greater than 40 Gy to the primary tumor is associated with better local control.  相似文献   

89.
Prognostic value of pololike kinase expression in melanomas   总被引:2,自引:0,他引:2  
Strebhardt K  Kneisel L  Linhart C  Bernd A  Kaufmann R 《JAMA》2000,283(4):479-480
  相似文献   
90.
The results of radiotherapy for brainstem tumors   总被引:2,自引:0,他引:2  
Objective: This analysis was performed to examine the outcome of adult and pediatric patients with brainstem tumors. Methods and materials: Forty patients with brainstem glioma were evaluated retrospectively. Included were 24 females and 16 males ranging in age from 3 to 81 years (median, 29.5 years). These patients were treated with various combinations of surgery, chemotherapy, and ratiotherapy (RT). The length of follow-up in survivors ranged from 0.6 to 20 years (median: 3.2 years, mean: 6 years). Survival rates were calculated with the Kaplan Meier method and differences between survival curves were calculated using the log-rank test. Results: The overall 2 and 5-year survival rates were 44% and 34%, respectively. The median survival time was 19 months. The 5-year survival rate was 54% for patients with tumors outside the pons compared to 21% for those with tumors involving the pons (p=0.04). The 5-year survival rate was 59% for patients with exophytic tumors as compared to 23% for those with intrinsic tumors (p=0.05). Patients undergoing subtotal resection had a 5-year survival rate of 53% compared to 28% for those having only a biopsy or no surgical intervention (p=0.04). None of the other potential prognostic or treatment related factors evaluated [patient age, tumor grade, tumor histology, radiotherapy parameters (including BID fractionation, 3-D treatment planning, or the use of doses > 55 Gy), or the administration of adjuvant chemotherapy] evaluated were associated with patient survival. Conclusions: Brainstem gliomas generally occur in younger individuals. The survival rates were better for patients with exophytic tumors, those involving sites other than the pons, and tumors amenable to subtotal resection. Improvements in the outcome of patients with brainstem gliomas will require new therapeutic approaches.  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