全文获取类型
收费全文 | 13248篇 |
免费 | 1724篇 |
国内免费 | 305篇 |
专业分类
耳鼻咽喉 | 215篇 |
儿科学 | 275篇 |
妇产科学 | 126篇 |
基础医学 | 739篇 |
口腔科学 | 186篇 |
临床医学 | 904篇 |
内科学 | 883篇 |
皮肤病学 | 541篇 |
神经病学 | 210篇 |
特种医学 | 2168篇 |
外国民族医学 | 15篇 |
外科学 | 1210篇 |
综合类 | 1573篇 |
预防医学 | 1058篇 |
眼科学 | 196篇 |
药学 | 578篇 |
4篇 | |
中国医学 | 288篇 |
肿瘤学 | 4108篇 |
出版年
2024年 | 6篇 |
2023年 | 199篇 |
2022年 | 219篇 |
2021年 | 441篇 |
2020年 | 473篇 |
2019年 | 461篇 |
2018年 | 500篇 |
2017年 | 499篇 |
2016年 | 597篇 |
2015年 | 626篇 |
2014年 | 1014篇 |
2013年 | 1311篇 |
2012年 | 878篇 |
2011年 | 870篇 |
2010年 | 655篇 |
2009年 | 587篇 |
2008年 | 596篇 |
2007年 | 569篇 |
2006年 | 552篇 |
2005年 | 513篇 |
2004年 | 432篇 |
2003年 | 402篇 |
2002年 | 331篇 |
2001年 | 310篇 |
2000年 | 248篇 |
1999年 | 205篇 |
1998年 | 171篇 |
1997年 | 165篇 |
1996年 | 162篇 |
1995年 | 127篇 |
1994年 | 109篇 |
1993年 | 99篇 |
1992年 | 86篇 |
1991年 | 102篇 |
1990年 | 80篇 |
1989年 | 88篇 |
1988年 | 74篇 |
1987年 | 65篇 |
1986年 | 61篇 |
1985年 | 78篇 |
1984年 | 59篇 |
1983年 | 54篇 |
1982年 | 43篇 |
1981年 | 34篇 |
1980年 | 39篇 |
1979年 | 30篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
目的 研究胸段食管癌逆向调强放射治疗(IMRT)中累及野照射与扩大野照射对危及器官(OAR)受照剂量的影响。方法 40例胸段食管癌患者分别行累及野靶区勾画和扩大野靶区勾画并勾画危及器官,制定IMRT计划,评估2个计划的靶区适形指数(CI)和均匀性指数(HI)及危及器官的剂量学参数,剂量学参数比较采用配对t检验。结果 2种计划的PTV均能满足处方剂量要求,PTV在CI、HI上相近(P = 0.317、0.130)。两组间平均肺剂量、两肺V5、两肺V20、两肺V30、脊髓Dmean、心脏Dmean、心脏Dmax、心脏V30、心脏V40、心脏V60差异均存在统计学意义(P < 0.01)。结论 胸段食管癌患者行累及野照射与扩大野比较,可降低正常器官的受照剂量,从而降低放射性损伤风险。 相似文献
2.
《Journal of thoracic oncology》2022,17(1):116-129
IntroductionManagement of central nervous system (CNS) metastases in patients with driver-mutated NSCLC has traditionally incorporated both tyrosine kinase inhibitors (TKIs) and intracranial radiation. Whether next generation, CNS-penetrant TKIs can be used alone without upfront radiation, however, remains unknown. This multi-institutional retrospective analysis aimed to compare outcomes in patients with EGFR- or ALK-positive NSCLC who received CNS-penetrant TKI therapy alone versus in combination with radiation for new or progressing intracranial metastases.MethodsData were retrospectively collected from three academic institutions. Two treatment groups (CNS-penetrant TKI alone versus TKI + CNS radiation therapy) were compared for both EGFR- and ALK-positive cohorts. Outcome variables included time to progression, time to intracranial progression, and time to treatment failure, measured from the date of initiation of CNS-penetrant TKI therapy.ResultsA total of 147 patients were included (EGFR n = 94, ALK n = 52, both n = 1). In patients receiving radiation, larger metastases, neurologic symptoms, and receipt of steroids were more common. There were no significant differences between TKI and CNS radiation therapy plus TKI groups for any of the study outcomes, including time to progression (8.5 versus 6.9 mo, p = 0.13 [EFGR] and 11.4 versus 13.4 mo, p = 0.98 [ALK]), time to intracranial progression (14.8 versus 20.5 mo, p = 0.51 [EGFR] and 18.1 versus 21.8 mo, p = 0.65 [ALK]), or time to treatment failure (13.8 versus 8.6 mo, p = 0.26 [EGFR] and 13.5 versus 23.2 mo, p = 0.95 [ALK]).ConclusionsThese results provide preliminary evidence that intracranial activity of CNS-penetrant TKIs may enable local radiation to be deferred in appropriately selected patients without negatively affecting progression. 相似文献
3.
评估AAA、AXB算法在鼻咽癌调强放射治疗(IMRT)中剂量计算的准确性,并分析空腔和骨性结构对剂量计算准确性造成的影响,以期指导临床应用。选取20例鼻咽癌IMRT计划导入SciMoCa中,使用蒙特卡罗算法进行独立验算,以蒙特卡罗计算结果为标准,对比光子剂量算法(AAA和AXB)对靶区和危及器官的剂量差异,以及γ通过率,并分析空腔和骨性结构对剂量分布的影响。结果表明:使用AAA、AXB算法的计划平均γ通过率分别为95.99%和96.26%,无统计学差异(P>0.05)。靶区内空腔区域AAA、AXB算法的平均剂量偏差为-2.26%和-0.33%,γ通过率为80.22%和98.55%;靶区内骨性结构区域AAA、AXB算法的平均剂量偏差为1.43%和0.17%,γ通过率为93.25%和99.72%。AAA算法下靶区内空腔区域的γ通过率与其体积呈线性正比(r=0.65),靶区骨性结构区域的γ通过率与其体积呈线性反比(r=-0.74);当空腔体积<20 cm3或骨性结构体积>10 cm3时,γ通过率均<95%。使用AAA算法时需要注意靶区内空腔和骨性结构的体积对剂量计算准确性的影响,而使用AXB算法时无需考虑空腔和骨性结构体积的影响,其计算结果与蒙特卡罗算法更接近。 相似文献
4.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):327-334.e2
ObjectiveSeveral trials have recently reported the safety of pulmonary resection after neoadjuvant immunotherapy with encouraging major pathological response rates. We report the detailed adverse events profile from a recently conducted randomized phase II trial in patients with resectable non–small cell lung cancer treated with neoadjuvant durvalumab alone or with sub-ablative radiation.MethodsWe conducted a randomized phase II trial in patients with non–small cell lung cancer clinical stages I to IIIA who were randomly assigned to receive neoadjuvant durvalumab alone or with sub-ablative radiation (8Gyx3). Secondary end points included the safety of 2 cycles of preoperative durvalumab with and without radiation followed by pulmonary resection. Postoperative adverse events within 30 days were recorded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0).ResultsSixty patients were enrolled and randomly assigned, with planned resection performed in 26 patients in each arm. Baseline demographics and clinical variables were balanced between groups. The median operative time was similar between arms: 128 minutes (97-201) versus 146 minutes (109-214) (P = .314). There was no 30- or 90-day mortality. Grade 3/4 adverse events occurred in 10 of 26 patients (38%) after monotherapy and in 10 of 26 patients (38%) after dual therapy. Anemia requiring transfusion and hypotension were the 2 most common adverse events. The median length of stay was similar between arms (5 days vs 4 days, P = .172).ConclusionsIn this randomized trial, the addition of sub-ablative focal radiation to durvalumab in the neoadjuvant setting was not associated with increased mortality or morbidity compared with neoadjuvant durvalumab alone. 相似文献
5.
《Cancer radiothérapie》2022,26(4):547-556
PurposeSurface-guided radiotherapy is useful for the pre-positioning and monitoring of radiotherapy. The purpose of this study was to investigate the impact of surface guidance on the repeatability of patient localization and to estimate the specific point at which high positional errors occur.Materials and methodsTen patients without the VOXELAN system (non-VXLN group) and 10 patients with the VOXELAN as the pre-positioning procedure (VXLN group) were included in this analysis. Twelve regions of interest (ROI) were defined in all the patients to verify any misalignment during radiotherapy. Thirteen ROIs were defined on the isocenter.ResultsCompared with the non-VXLN group, the translational positional errors of the VXLN group were the same for all the ROIs. The mean translational positional errors of the VXLN group in the longitudinal direction were approximately 0.1 mm, and the standard deviation was the largest among the three directions in all the ROIs. The magnitude of the standard deviation in the non-VXLN group varied independently of the ROI and direction. The standard deviations of the VXLN group in the longitudinal direction were large in all the ROIs, while the standard deviations in the vertical and lateral directions were small.ConclusionPre-positioning with a surface guidance system reduced the body twist and rotation, which could not be corrected by image-guided radiotherapy alone. Since the VOXELAN can detect positioning errors quickly and without additional radiation exposure to the patient, it can be used as a tool for pre-positioning in radiotherapy. 相似文献
6.
7.
目的 本研究应用声辐射力脉冲成像(Acoustic Radiation Force Impulse ARFI)技术对慢性乙型肝炎肝硬化患者进行脾脏弹性检测和分析,探讨和对比脾脏ARFI弹性及脾脏ARFI弹性联合血小板计数(Platelet Count PC)在预测乙肝肝硬化食道静脉曲张的临床应用价值。方法 对232例慢性乙型肝炎肝硬化患者应用ARFI技术检测脾脏实时超声弹性,并测量PC,所有患者均于检测前后一周内行胃镜检查明确食管静脉曲张情况,以胃镜结果为金标准,应用受试者工作特征(receiver operating characteristic, ROC)曲线比较脾脏ARFI弹性、PC、及脾ARFI弹性联合PC诊断肝硬化食管静脉曲张的临床价值。结果 食道静脉曲张组脾脏ARFI弹性和PC分别为3.52(3.16-3.87)m/s 和62(41-88.25),无食道静脉曲张组脾脏ARFI弹性和PC分别为2.91(2.35-3.35)m/s和129.5(87.25-196.25)。脾脏ARFI弹性和PC在两组间比较的差异均具有统计学意义(P<0.001 )。单独脾脏ARFI弹性及脾脏ARFI弹性联合PC的ROC曲线下面积分别为0.76和0.83,差异具有统计学意义(P = 0.0021)。结论 脾脏ARFI弹性测值联合PC较单纯脾脏ARFI弹性能更准确的无创预测慢性乙型肝炎肝硬化食管静脉曲张的存在,具有良好的临床应用前景。 相似文献
8.
9.
10.