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   17292篇
  免费   2269篇
  国内免费   302篇
耳鼻咽喉   271篇
儿科学   264篇
妇产科学   222篇
基础医学   624篇
口腔科学   243篇
临床医学   835篇
内科学   824篇
皮肤病学   120篇
神经病学   174篇
特种医学   855篇
外国民族医学   44篇
外科学   1787篇
综合类   2066篇
预防医学   653篇
眼科学   138篇
药学   628篇
  11篇
中国医学   228篇
肿瘤学   9876篇
  2024年   28篇
  2023年   267篇
  2022年   464篇
  2021年   797篇
  2020年   751篇
  2019年   718篇
  2018年   663篇
  2017年   726篇
  2016年   809篇
  2015年   768篇
  2014年   1249篇
  2013年   1229篇
  2012年   1124篇
  2011年   1179篇
  2010年   1065篇
  2009年   976篇
  2008年   826篇
  2007年   982篇
  2006年   871篇
  2005年   714篇
  2004年   584篇
  2003年   509篇
  2002年   409篇
  2001年   368篇
  2000年   291篇
  1999年   255篇
  1998年   216篇
  1997年   175篇
  1996年   133篇
  1995年   97篇
  1994年   75篇
  1993年   51篇
  1992年   63篇
  1991年   45篇
  1990年   34篇
  1989年   31篇
  1988年   47篇
  1987年   31篇
  1986年   21篇
  1985年   50篇
  1984年   32篇
  1983年   28篇
  1982年   28篇
  1981年   19篇
  1980年   19篇
  1979年   12篇
  1978年   9篇
  1977年   14篇
  1976年   5篇
  1975年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
放射治疗骨转移癌疼痛47例临床分析   总被引:10,自引:0,他引:10  
目的 观察骨转移癌疼痛放射治疗方法对疼痛的缓解效果。方法47例患者60处骨转移灶均采用6 MV X线放射治疗。剂量方案采用两种方法:A方案:30—51 Gy/10~17f/2~4周,B方案:25~30 Gy/5—6f/1~2周。结果分次方案对疼痛缓解率无明显影响,总有效率均为91.5%,但常规分次放疗3~4次后疼痛缓解,而低分割放疗1—2次后疼痛即缓解。结论 骨转移癌放射治疗止痛效果确切、迅速,副作用小,对大部分病例可采用低分割方案。  相似文献   
72.
BACKGROUND: The addition of short course pre-operative radiotherapy to total mesorectal excision reduces local recurrence in resectable adenocarcinoma of the rectum. In a previous retrospective study potential factors associated with early complications following this combination were identified. The aim of this study was to examine these relationships in a prospective multicentre audit. METHODS: One hundred and seven patients who received short course pre-operative radiotherapy in four cancer centres between 1 October 2001 and 30 September 2002 were included. Data including patient age, radiotherapy field length, overall treatment time, operation type, surgical outcomes and complications occurring within 3 months of the 1st day of radiotherapy were collected. These were compared and combined with the previously studied cohort of 176 patients treated at one centre between 1st January 1998 and 31st December 1999. RESULTS: In the prospective cohort only patient age (P=0.001) was significantly associated with acute complications. However, both the overall treatment time (median 9.0 vs 11.0 days P <0.0001) and field length (median 16.6 vs 17.0 cm P=0.03) were significantly shorter in this cohort when compared to the previous retrospective study. In patients from both studies (n=283), increasing age (P=0.002) and field length (independent of operation type) (P=0.02) were independently associated with an increased risk of acute complications. CONCLUSIONS: This study suggests that meticulous selection of patients for short course pre-operative radiotherapy and smaller planning target volumes may be associated with a lower risk of acute complications. The use of MRI scanning to stage pelvic disease may reduce the number of patients with R1 resections receiving short course pre-operative radiotherapy.  相似文献   
73.
The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.  相似文献   
74.
AMEDLINEsearchwasconductedtoidentifystudiespublishedfromJanuary1999toMarch2004thatcom-paredinjectablecalciumphosphatebone(NorianSRS)cementwithconventionaltreatmentindistalradialfrac-tures.Fromalistof13articlesidentifiedfromthesearchstrategy,fourarticleswe…  相似文献   
75.
OBJECTIVE: The indications for pre-operative radiotherapy in rectal cancer are still unclear with the exception of T4 tumours. The aim of this study was to assess local and overall recurrence in patients with T1-T3 rectal cancers undergoing total mesorectal excision (TME). METHODS: Prospective data was collected from 150 patients with rectal cancer treated in one surgical centre between July 1997 and July 2002. One hundred and twenty-nine primary resections were carried of which 102 were with curative intent. Seventy-nine patients with T1-T3 tumours were included in the analysis. Nine had local resections and 70 underwent TME; 19 of the 70 patients were node positive and 51 were node negative. RESULTS: At a median follow-up of 37 months (range 19-79 months) there were 3 (4.3%) isolated local recurrences. One node positive patient developed isolated local recurrence compared with 2 node negative patients. The node positive patient died from a myocardial infarction while the two node negative patients died as a consequence of local recurrence. Three (4.3%) of 70 patients developed systemic relapse all of whom were node positive. The cancer specific mortality rate over the same follow-up period was 3/19 for node positive patients and 2/51 for node negative patients. Of 9 patients who had local resections, none developed local recurrence or systemic relapse. CONCLUSIONS: With TME the rate of local recurrence in T1-T3 tumours is low. Our results do not support the use of pre-operative radiotherapy for these patients.  相似文献   
76.
Two adult patients with the diagnosis of gastric lymphoma who developed adenocarcinoma of the stomach 8 years after the treatment are presented. Both patients were treated by subtotal gastrectomy followed by irradiation of 4,000–4,500 cGy to the epigastric region and six courses of chemotherapy (vincristine, cyclophosphamide, prednisolone). In our review of the literature, 16 cases of gastric adenocarcinoma following the treatment of gastric lymphoma were found and listed with details. The factors influencing the development of this secondary carcinoma, mainly those treatment related are discussed. The possible role of both radiotherapy and chemotherapy in shortening the latent period for the development of stump carcinoma is emphasized. © 1993 Wiley-Liss, Inc.  相似文献   
77.
This paper describes 29 patients with Ewing's sarcoma of bone treated between 1975 and 1990 at the University of Nijmegen Hospital, Nijmegen, The Netherlands. Osteomyelitis was the primary diagnosis in 24%. Treatment consisted of chemotherapy in combination with surgery and/or radiotherapy. Nine patients received radiotherapy only; five of them died of disease. Five patients underwent an intralesional excision; four of them died of disease. Twelve patients underwent a wide excision; there is no evidence of disease in any of them. Three patients underwent a radical disarticulation; all died of disease. The disease-free survival at 1.5 years was 66%. This figure at 5 years was 55%. After wide excision and reconstruction in tumors of expendable, femoral or radial bones good functional results were obtained in all cases. © 1995 Wiley-Liss, Inc.  相似文献   
78.
Background : The results of management of seminoma of the testis at the Department of Radiation Oncology St Vincent's Hospital, Sydney were evaluated retrospectively to: (i) establish that outcomes were in keeping with published results from centres in Australia and overseas; (ii) assess the impact of chemotherapy on management; and (iii) to determine ‘best practice’ management protocols based on our results and a review of the relevant literature. Methods : (i) Assessment of treatment results for stage I and II seminoma of the testis treated by post-orchidectomy radiotherapy and/or chemotherapy at St Vincent's Hospital between 1979 and 1993; (ii) literature review of published data from Australian and overseas centres on the management of seminoma of the testis, and in particular the use of surveillance or chemotherapy either alone, at time of relapse or combined with radiotherapy; and (iii) development of recommendations for use as management protocols in our department. Results : Our data and a review of the literature suggest that post-orchidectomy radiotherapy with chemotherapy for relapse in stage I and IIA disease results in long-term cure rates approaching 100%. Treatment with chemotherapy either routinely or selectively or using a surveillance policy is unlikely to show any improvement in outcome and may be less cost-effective and/or produce increased morbidity and the risk of secondary leukaemia. For stage IIB disease (5–10 cm) the use of initial combination chemotherapy with or without subsequent radiotherapy did not appear to give better outcomes than initial radical radiotherapy alone, reserving chemotherapy or further radiotherapy for relapse. For bulkier stage IIB disease (> 10cm). the use of initial chemotherapy plus consolidation radiotherapy appeared to be an appropriate treatment. Conclusions : Management protocols for seminoma of the testis at St Vincent's Hospital, Sydney Department of Radiation Oncology currently are (i) stage I, IA and IIB (5–10 cm): post-orchidectomy radiotherapy alone with chemotherapy or further radiotherapy for relapse; and (ii) stage IIB (> 10 cm) disease: initial chemotherapy post-orchidectomy followed by radiotherapy to sites of initial disease involvement.  相似文献   
79.
OBJECTIVE: Pre-operative staging of rectal cancer should identify patients with extrarectal spread, who might benefit from pre-operative radiotherapy, and patients with minimal sphincteral involvement, who can avoid permanent colostomy. The aim of this study was to assess the accuracy of Magnetic Resonance Imaging (MRI) to predict tumour stage and sphincter status. PATIENTS AND METHODS: Thirty-three patients with a rectal tumour were pre-operatively assessed by MRI with a phased-array coil. Imaging results were correlated with the final pathological findings. RESULTS: The overall accuracy of pre-operative staging with MRI was 88% (k = 0.75) for extramural tumour invasion and 59% (k = 0.26) for lymph node metastases. MRI correctly evaluated the infiltration of the anal sphincters in 87% of patients (7 of 8 patients with low rectal tumour). CONCLUSION: MRI provides the surgeon with valuable information regarding extramural tumour spread and sphincteral involvement, enabling appropriate selection of patients for pre-operative adjuvant therapy or sphincter-saving surgery.  相似文献   
80.
目的:研讨放疗联合化疗(小剂量顺铂)对转移性骨癌的止痛效果。方法:将符合条件的转移性骨癌患者分成放疗联合顺铂组、单纯放疗组,观察止痛疗效。结果:放疗联合顺铂组与单纯放疗组,1、2级疼痛止痛疗效相似(P〉0.05)。3级疼痛完全缓解率放疗联合顺铂组优于单纯放疗组(P〈0.05)。结论:放疗联合顺铂治疗转移性骨癌,对重度骨痛者疗效明显,可提高完全缓解率,不明显增加毒副作用,该方法值得临床应用。  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