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   9864篇
  免费   896篇
  国内免费   114篇
耳鼻咽喉   311篇
儿科学   29篇
妇产科学   163篇
基础医学   191篇
口腔科学   115篇
临床医学   622篇
内科学   408篇
皮肤病学   31篇
神经病学   224篇
特种医学   913篇
外科学   616篇
综合类   980篇
预防医学   343篇
眼科学   27篇
药学   490篇
  5篇
中国医学   84篇
肿瘤学   5322篇
  2024年   11篇
  2023年   112篇
  2022年   253篇
  2021年   350篇
  2020年   290篇
  2019年   259篇
  2018年   338篇
  2017年   310篇
  2016年   333篇
  2015年   272篇
  2014年   613篇
  2013年   536篇
  2012年   693篇
  2011年   725篇
  2010年   632篇
  2009年   698篇
  2008年   638篇
  2007年   620篇
  2006年   562篇
  2005年   383篇
  2004年   301篇
  2003年   237篇
  2002年   221篇
  2001年   184篇
  2000年   172篇
  1999年   158篇
  1998年   127篇
  1997年   112篇
  1996年   108篇
  1995年   98篇
  1994年   48篇
  1993年   22篇
  1992年   27篇
  1991年   30篇
  1990年   21篇
  1989年   20篇
  1988年   10篇
  1987年   14篇
  1986年   14篇
  1985年   55篇
  1984年   54篇
  1983年   38篇
  1982年   40篇
  1981年   33篇
  1980年   41篇
  1979年   42篇
  1977年   6篇
  1976年   5篇
  1974年   2篇
  1973年   4篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
1.
《Cancer radiothérapie》2022,26(3):502-516
The aim of the review was to present the current literature status about replanning regarding anatomical and dosimetric changes in the target and OARs in the head and neck region during radiotherapy, to discuss and to analyze factors influencing the decision for adaptive radiotherapy of head and neck cancer patients. Significant progress has been made in head and neck patients’ evaluation and qualification for adapted radiotherapy over the past ten years. Many factors leading to anatomical and dosimetric changes during treatment have been identified. Based on the literature, the most common factors triggering re-plan are weight loss, tumor and nodal changes, and parotid glands shrinkage. The fluctuations in dose distribution in the clinical area are significant predictive factors for patients’ quality of life and the possibility of recovery. It has been shown that re-planning influence clinical outcomes: local control, disease free survival and overall survival. Regarding literature studies, it seems that adaptive radiotherapy would be the most beneficial for tumors of immense volume or those in the nearest proximity of the OARs. All researchers agree that the timing of re-planning is a crucial challenge, and there are still no clear consensus guidelines for time or criteria of re-planning. Nowadays, thanks to significant technological progress, the decision is mostly made based on observation and supported with IGRT verification. Although further research is still needed, adaptive strategies are evolving and now became the state of the art of modern radiotherapy.  相似文献   
2.
《Cancer radiothérapie》2022,26(8):1034-1044
PurposeAssess the feasibility of a randomized controlled trial (RCT) exploring the use of medical imaging as a therapeutic education (TPE) intervention in external radiation therapy.Materials and methodsExperimental feasibility trial of “RCT” type carried out in a single-center, between November 2019 and March 2020, following adult patients treated by thoracic radiotherapy. In addition to the information usually given, the experimental group benefited from an intervention consisting in the visualization of their own medical images using the open-source software “Stone of Orthanc”.ResultsForty-nine patients were recruited with a refusal rate of 8.16% (4/49). 20 patients were withdrawn from the study for health reasons (COVID), 10 for medical reasons. All the remaining 15 participants completed the process. Although not significant, the experimental group showed a median gain in the perception of knowledge compared to the control group (+ 1.9 (1.6 – 2.2)) vs (+ 1.4 (1.4 – 1.8)), as well as a decrease in scores related to anxiety (? 3.0 (?4.5 - (?2.0)) vs ? 1.0 (?5.0 - 0.0)) and emotional distress ((? 5.0 (? 7.5 - (? 3.5)) vs (? 2.0 (? 5.0 - (? 1.0)) A significant reduction (p = 0.043) is observed for the depression score ((? 2.0 (?3.0 - (?1.5)) vs (0.0 (0.0 – 0.0)).ConclusionThis study demonstrates the feasibility of the project, with promising preliminary results. Some adaptations in order to conduct a larger-scale RCT are highlighted.  相似文献   
3.
目的探讨放疗干预对宫颈癌荷瘤小鼠的抑瘤作用及其对辅助性T细胞1(Th1)/Th2细胞比例的影响。方法建立宫颈癌荷瘤小鼠模型,随机分为荷瘤组和放疗组,每组各10只,另设对照组10只。放疗组进行放疗干预14天,荷瘤组和对照组不治疗。放疗后4、6、8、10、12、14天测量肿瘤体积;末次治疗后,ELISA法测定血清干扰素-γ(IFN-γ)、白介素-2(IL-2)、IL-4、IL-10含量;计算抑瘤率、胸腺指数和脾脏指数;HE染色观察肿瘤组织学变化;TUNEL染色观察肿瘤组织细胞凋亡情况;流式细胞术检测脾脏Th1/Th2细胞比例;RT-qPCR和Western blot检测脾脏T盒子转录因子(T-bet)、GATA结合蛋白3(GABA-3)mRNA和蛋白表达。结果与荷瘤组比较,放疗组小鼠4、6、8、10、12、14天肿瘤体积及瘤质量减小,血清IL-2、IFN-γ升高,IL-4、IL-10降低,胸腺指数、脾脏指数升高,Th1细胞比例、Th1/Th2增加,Th2细胞比例减少,T-bet mRNA和蛋白及T-bet/GATA-3表达升高,GATA-3 mRNA和蛋白表达降低(P<0.05)。HE染色显示,荷瘤组肿瘤细胞数量较多,核大深染,无明显坏死;放疗组肿瘤细胞数量减少,出现大量坏死组织。TUNEL染色显示,荷瘤组TUNEL阳性细胞较少,放疗组TUNEL阳性细胞明显增多。结论放疗对宫颈癌荷瘤小鼠具有明显抑瘤作用,可能是通过调节T-bet/GATA-3表达,促进Th1/Th2分化平衡,增强机体免疫功能发挥作用。  相似文献   
4.
The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radiotherapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications. Thin (≈1 μm) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl3, have been grown for the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have been tested in real-time configuration to evaluate the dose delivered by a 6 MV photon beam from a linear accelerator. Linearity of the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose rate has been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and wide bandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configuration allows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the active volume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatial resolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generation of flexible, transmission, real time dosimeters for clinical radiotherapy.  相似文献   
5.
6.
Locally advanced rectal cancer has a rising global incidence. Over the last 4 decades, advances first in surgery and later in radiotherapy and chemoradiotherapy have improved outcomes, particularly with regard to local recurrence. Unfortunately, distant metastases remain a significant problem. In clinical trials of patients with stage II and III disease, distant relapse occurs in 25% to 30% of patients regardless of the treatment approach. Recent phase 3 trials have therefore focused on intensification of systemic therapy for localized disease, with an aim of reducing the distant relapse rate. Early results of trials of total neoadjuvant therapy with combination systemic therapy provided in the neoadjuvant setting are promising; for the first time, a significant improvement in the rate of distant relapse has been noted. Longer-term follow-up is eagerly awaited. On the other hand, trimodal therapy with chemotherapy, radiotherapy, and surgery is toxic. Several trials are currently assessing the feasibility of a watch-and-wait approach, omitting surgery in those with complete response to neoadjuvant treatment, in an attempt to reduce the burden of treatment on patients. The future for rectal cancer patients is likely to be highly personalized, with more intense approaches for high-risk patients and omission of unnecessary therapy for those whose disease responds well to initial treatment. Biomarkers such as circulating tumor DNA will help to more accurately stratify patients into risk groups. Improvements in survival and quality of life are expected as the results of ongoing research become available throughout the next decade.  相似文献   
7.
IntroductionInterprofessional learning (IPL) is a vital aspect of training in radiation oncology professions, yet is rarely delivered to those professionals who work most closely together in clinical practice. Scenario-based learning using simulation facilities provides a unique opportunity to facilitate this learning and this project aimed to determine the impact and value of this initiative.MethodsSmall groups comprising post-graduate diploma pre-registration therapeutic radiographers, medical physics trainees and radiation oncology registrars were challenged with 4 plausible and challenging radiotherapy scenarios within an academic simulation centre. Pre- and post-event completion of the “Readiness for Interprofessional Learning Scale” measured impact and a Likert-style survey gathered feedback from participants.ResultsThe session increased participants' teamwork and collaboration skills as well as strengthening professional identities. Participants reported high levels of enjoyment related to collaborative working, communication and observing other professionals deploying their technical skills and specialist knowledge.ConclusionAlthough beneficial, simulated scenarios offering equal opportunities for engagement across the professions are challenging to plan and timetabling issues between the 3 groups present significant difficulties. The safe environment and unique opportunity for these groups to learn together was particularly well received and future oncology-specific simulated scenario sessions are planned with larger cohorts.Implications for practiceSimulated scenario training can be used to improve team working across the radiotherapy interprofessional team and may have wider use in other specialist interdisciplinary team development.  相似文献   
8.
《Radiography》2021,27(4):1094-1098
IntroductionEducation and training strategies in Therapeutic Radiography are challenged in recruiting and retaining students in the profession. Clinical oncology centres are often viewed as stressful environments for students due to rapid advances in technology and reported bullying and harassment. Educators continue to work with clinical partners in developing strategies to promote resilience and reduce negative attitudes. The overall aim of this project was to explore the use of Triple R sessions as a new method of student reflection.MethodsThe Review, Reflect and Re-focus (Triple R) sessions were designed to enable students to learn from their clinical experiences and; apply their understanding and positivity when they return to clinical placement. Eleven sessions were completed across 7 student cohorts in one academic year. Qualitative data was collected from feedback forms, as well as academic field notes, and analysed thematically.ResultsTwo main themes focused on: (1) staff interactions and (2) student expectations. Results showed that Triple R sessions were helpful in drawing out the experiences of students in a positive way to reflect on their own development. The sessions enabled critical self-analysis and improved problem-solving skills, particularly evident during peer discussions.ConclusionTriple R sessions explored the influence of a positive approach on students' perceptions of their overall placement. Evaluation of the data indicated that, following academic and peer discussion, students' perceptions tended to be a more positive overall view of their placement.Implications for practiceTriple R sessions can be used in academic and clinical environments to enable positive student interactions.  相似文献   
9.
Background and objectivesThe locoregional management of breast cancer has a critical impact on prognosis. This study aimed to analyze the effectiveness of radiotherapy against the deleterious effect of positive surgical margins on disease outcomes.MethodsRetrospective, single-center study enrolled 721 breast cancer patients with a median follow-up of approximately 64.50 months (3.67–247.40). Analyses were performed considering the end of adjuvant therapy, except endocrine therapy. Kaplan-Meier and Cox regression were performed to obtain the predictive value of treatments.ResultsThe minimally adequate radiotherapy (≥45 cGy) was associated with improved outcomes in breast cancer patients compared to inadequate radiotherapy (<45 cGy/no) by controlling locoregional relapses and distant metastasis. In patients with positive surgical margins (n = 53), radiotherapy was associated with an approximate decrease of 90% in locoregional relapse risk [adjusted HR: 0.108 (0.012–0.932), p = 0.043]. Radiotherapy did not alter the adverse effect of positive surgical margins, especially in patients with a higher risk of poorly differentiated tumors (n = 146), presence of lymphovascular invasion (n = 163), and triple-negative subtype (n = 113). Notwithstanding, radiotherapy was associated with respective decreases of distant metastasis risk of 75.2% [adjusted HR: 0.248 (0.081–0.762), p = 0.015] and 67.8% [adjusted HR: 0.322 (0.101–1.029), p = 0.056] in patients with triple-negative tumors or with lymphovascular invasion.ConclusionAdequate radiotherapy is associated with better outcomes in breast cancer. Despite improving locoregional relapse-free survival, radiotherapy does not ablate positive surgical margins, a factor of poorer prognosis that prevails mainly in patients with factors of higher relapse risk.  相似文献   
10.
《Cancer radiothérapie》2022,26(4):585-593
PurposeTo explore the potential protective effect of Kanglaite injection against radiotherapy-induced mucositis in patients with head and neck cancer.Patients and methodsThis was an open-label, single-arm, and phase II trial. The primary endpoint was the incidence of grade 3–4 radiation-induced mucositis. The secondary endpoints were hematological toxicity, non-hematological toxicity, nutritional status, and quality of life. All patients received 20 g Kanglaite daily concurrently with radiotherapy.ResultsThe data of 46 patients were available for analysis. The incidence rates of grade 3 mucositis, pain, dysphagia, and neutropenia were 10.9%, 2.2%, 10.9%, and 6.5%, respectively, while the incidence of grade 4 acute toxicities was zero. The rate of opioid use was 2.2%. Radiotherapy dose reduction was 2.2% and no irradiation field was modified. The nutritional supports were oro-enteral nutritional supplements (13.0%), TPN (10.9%), and feeding tubes (0%) during radiotherapy. After radiotherapy, 52.2% of patients lost weight, and the weight loss was <10%. The mean pain score in the QLQ-H&N35 and QLQ-C30 was <50. Patients had nearly normal physical, emotional, and cognitive functions.ConclusionsA low incidence of grade 3–4 radiation-induced mucositis and no severe acute toxic events, with favorable nutritional status and quality of life, were observed in cancer patients after Kanglaite injection. Our findings highlight the need for a prospective, multicenter, and randomized study to investigate the effect of Kanglaite injection on the reduction of radiation-induced mucositis in patients with head and neck cancer.  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