全文获取类型
收费全文 | 641篇 |
免费 | 80篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 5篇 |
基础医学 | 96篇 |
口腔科学 | 1篇 |
临床医学 | 29篇 |
内科学 | 44篇 |
神经病学 | 22篇 |
特种医学 | 28篇 |
外国民族医学 | 7篇 |
外科学 | 17篇 |
综合类 | 87篇 |
预防医学 | 25篇 |
眼科学 | 4篇 |
药学 | 69篇 |
中国医学 | 6篇 |
肿瘤学 | 266篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 26篇 |
2016年 | 25篇 |
2015年 | 30篇 |
2014年 | 43篇 |
2013年 | 45篇 |
2012年 | 41篇 |
2011年 | 40篇 |
2010年 | 33篇 |
2009年 | 51篇 |
2008年 | 40篇 |
2007年 | 32篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 26篇 |
2003年 | 33篇 |
2002年 | 22篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有727条查询结果,搜索用时 46 毫秒
11.
12.
Conclusion: The current study confirmed the significant high mobility group box 1 (HMGB1) was promoted in human nasopharyngeal carcinoma (NPC) tissues by Epstein-Barr virus (EBV) infection, in association with the malignant status of NPC, and promoted the proliferation NPC cells RAGE-dependently. Objectives: The present study was to examine the association of HMGB1 over-expression in human NPC with the EBV-positivity and to determine the regulatory role of HMGB1 on the proliferation of NPC cells in vitro. Methods: Real-time PCR and Western blotting were utilized to examine the HMGB1 expression. EBV infection in CNE-2 cells was performed to investigate the HMGB1 promotion by EBV infection. RNA interference technology was utilized for the RAGE knockout. Results: It was demonstrated that HMGB1 was significantly higher in both mRNA and protein levels in the EBV-positive NPC tissues, in marked association with the malignant status of NPC, and with the LMP1 DNA level in EBV-positive NPC samples. In addition, the MTT assay, growth curve, and the colony forming assay confirmed the promotion by HMGB1 to the proliferation of CNE-2 cells, depending on RAGE. 相似文献
13.
14.
15.
目的研究螺旋CT与MRI诊断鼻咽癌颅底骨质侵犯的价值。方法收集本院2010年1—12月经病理证实的29例鼻咽癌颅底骨质侵犯患者的临床资料.并对这些患者的CT和MRI检查结果进行分析。结果CT的表现为虫蚀样,皮质骨模糊增厚,或有皮质骨因硬化而增生,在同一病例中,可在不同部位出现骨质破坏,MRI的影像表现为高信号的骨髓信号消失,取代为肿瘤的中等信号。且增强扫描后有明显强化。29例患者中,CT检出10例,检出率为34.5%,其中,单部位3例,占10-3%;多部位7例,占24.1%。MRI检出21例,检出率为72.4%,其中,单部位8例,占27.6%;多部位13例,占44.8%,两种检测结果比较,差异有统计学意义(P〈0.05)。CT检出颅底各部位骨质侵犯最多的是岩锥尖,其次是翼板:MRI检出颅底各部位骨质侵犯最多的是岩锥尖,其次是斜坡骨。结论MRI诊断能够提高鼻咽癌颅底骨质侵犯的确诊率,有利于早日确诊并及时得以治疗,在鼻咽癌颅底骨质侵犯的定位和治疗方案的选择上有一定的价值。 相似文献
16.
S. Kidambi S. B. Patel 《Xenobiotica; the fate of foreign compounds in biological systems》2013,43(7-8):1119-1139
1.?Whole-body sterol (cholesterol and xenosterol) balance is delicately regulated by the gastrointestinal tract and liver, which control sterol absorption and excretion, respectively, in addition to the contribution to the cholesterol pool by whole-body cholesterol synthesis. In the past ten years enormous strides have been made not only in establishing that specific transporters mediate the entry and exit of sterols and how these may regulate selective sterol access to the body pools, but also in how these pathways operate to integrate these physiological pathways.2.?The entry of sterols from the gastrointestinal and biliary canalicular lumen into the body is mediated by NPC1L1, which was discovered by a novel method, via a genomics–bioinformatics approach.3.?Identification of the genetic basis responsible for causing sitosterolaemia, characterized by plant sterol accumulation, led to the identification of two half-transporters (ABCG5 and ABCG8) that normally efflux plant sterols (and cholesterol) into the intestinal and biliary lumen for faecal excretion.4.?The objective of this review is to provide up-to-date knowledge on genomics, proteomics and function of these two transporter systems. 相似文献
17.
18.
目的:探讨小鼠肝脏过表达人NPC1L1对LXR诱导的小鼠胆固醇分泌的影响。方法:给予野生型小鼠(WT)和肝脏过表达人NPC1L1的转基因小鼠(L1Tg)胃饲LXR激动剂(T0901317)7 d后,抽提小鼠粪便总脂质并检测核心甾醇的含量,检测小鼠的血浆脂质水平,分析肝脏ABCG5和ABCG8的mRNA表达水平。结果:L1Tg小鼠与WT小鼠相比,除血浆游离胆固醇含量显著升高外,粪便核心甾醇含量及肝脏ABCG5和G8的mRNA水平差异无统计学意义;在胃饲T0901317 1 w后,WT小鼠的粪便核心甾醇含量由[(3.22±0.44)升高到(28.68±1.05)μmol.d-1.100 g-1],血浆总胆固醇、游离胆固醇、胆固醇酯和磷脂的含量均显著升高,同时肝脏的ABCG5和G8的mRNA水平也分别上调了5倍和2倍;然而,L1Tg小鼠经T0901317处理后,与T0901317处理的WT小鼠相比,粪便核心甾醇的分泌减少了56%,血浆游离胆固醇含量升高了40%,肝脏的ABCG5和G8的mRNA水平分别降低了52.4%和40.6%。结论:肝脏特异表达人NPC1L1降低了LXR诱导的小鼠粪便核心甾醇的分泌,并升高了血浆游离胆固醇水平,可能与下调LXR诱导的肝脏ABCG5和G8 mRNA表述水平有一定关系。 相似文献
19.
Daniela Dünn-Kittenplon Asaf Ashkenazy-Titelman Inna Kalt Jean-Paul Lellouche Yaron Shav-Tal Ronit Sarid 《Viruses》2021,13(4)
Kaposi’s sarcoma-associated herpesvirus (KSHV) is a cancer-related herpesvirus. Like other herpesviruses, the KSHV icosahedral capsid includes a portal vertex, composed of 12 protein subunits encoded by open reading frame (ORF) 43, which enables packaging and release of the viral genome into the nucleus through the nuclear pore complex (NPC). Capsid vertex-specific component (CVSC) tegument proteins, which directly mediate docking at the NPCs, are organized on the capsid vertices and are enriched on the portal vertex. Whether and how the portal vertex is selected for docking at the NPC is unknown. Here, we investigated the docking of incoming ORF43-null KSHV capsids at the NPCs, and describe a significantly lower fraction of capsids attached to the nuclear envelope compared to wild-type (WT) capsids. Like WT capsids, nuclear envelope-associated ORF43-null capsids co-localized with different nucleoporins (Nups) and did not detach upon salt treatment. Inhibition of nuclear export did not alter WT capsid docking. As ORF43-null capsids exhibit lower extent of association with the NPCs, we conclude that although not essential, the portal has a role in mediating the interaction of the CVSC proteins with Nups, and suggest a model whereby WT capsids can dock at the nuclear envelope through a non-portal penton vertex, resulting in an infection ‘dead end’. 相似文献
20.
《Medical Dosimetry》2014,39(3):246-250
This study aims to determine the optimal beam design among various combinations of field numbers and beam trajectories for intensity-modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB) technique for the treatment of nasopharyngeal cancer (NPC). We used 10 fields with gantry angles of 155°, 130°, 75°, 25°, 0° L, 0° R, 335°, 285°, 230°, and 205° denoted as F10. To decrease doses in the spinal cord, the F10 technique was designed by featuring 2 pairs of split-opposed beam fields at 155° to 335° and 205° to 25°, as well as one pair of manually split beam fields at 0°. The F10 technique was compared with 4 other common field arrangements: F7E, 7 fields with 50° equally spaced gantry angles; F7, the basis of F10 with 155°, 130°, 75°, 0°, 285°, 230°, and 205°; F9E, 9 fields with 40° equally spaced gantry angles; and FP, 7 posterior fields with 180°, 150°, 120°, 90°, 270°, 240°, and 210°. For each individual case of 10 patients, the customized constraints derived after optimization with the standard F10 technique were applied to 4 other field arrangements. The 4 new optimized plans of each individual case were normalized to achieve the same coverage of planning target volume (PTV)63 Gy as that of the standard F10 technique. The F10 field arrangement exhibited the best coverage in PTV70 Gy and the least mean dose in the trachea-esophagus region. Furthermore, the F10 field arrangement demonstrated the highest level of conformity in the low-dose region and the least monitor unit. The F10 field arrangement performed more outstandingly than the other field arrangements in PTV70 Gy coverage and spared the central organ. This arrangement also exhibited the highest conformity and delivery efficiency. The F10 technique is recommended as the standard beam geometry for the SIB-IMRT of NPC. 相似文献