全文获取类型
收费全文 | 8820篇 |
免费 | 366篇 |
国内免费 | 284篇 |
学科分类
医药卫生 | 9470篇 |
出版年
2024年 | 3篇 |
2023年 | 30篇 |
2022年 | 83篇 |
2021年 | 182篇 |
2020年 | 169篇 |
2019年 | 103篇 |
2018年 | 145篇 |
2017年 | 131篇 |
2016年 | 185篇 |
2015年 | 216篇 |
2014年 | 450篇 |
2013年 | 452篇 |
2012年 | 588篇 |
2011年 | 789篇 |
2010年 | 579篇 |
2009年 | 693篇 |
2008年 | 731篇 |
2007年 | 701篇 |
2006年 | 659篇 |
2005年 | 580篇 |
2004年 | 455篇 |
2003年 | 345篇 |
2002年 | 249篇 |
2001年 | 150篇 |
2000年 | 166篇 |
1999年 | 123篇 |
1998年 | 135篇 |
1997年 | 109篇 |
1996年 | 80篇 |
1995年 | 60篇 |
1994年 | 39篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 11篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有9470条查询结果,搜索用时 31 毫秒
1.
Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers. 相似文献
2.
《Journal of microbiology, immunology, and infection》2021,54(4):748-751
IntroductionThe novel coronavirus disease (COVID-19) could cause a severe acute respiratory infectious disease, showing a high mortality rate of 12–45% among cases who required intensive care unit admission. COVID-19 pneumoniaPatients and methodsFor the purpose of identifying clinical manifestations and radiological findings of COVID-19 pneumonia, we reviewed all cases of COVID-19 pneumonia which were published by the homepage of the Japanese Association for Infectious Diseases from Feb 5 2020 until April 30 2020, including our cases. All patients were diagnosed based on positive results of the novel coronavirus-real-time RT-PCR with chest computed tomography (CT) findings.ResultsA total of 92 patients were enrolled in this study. The median age was 66 years (range 16–92 years). For all, 50 (54%) were males. The most common underlying disease was hypertension in 32 (36%). Any comorbidity was seen in 60 (67%). The mortality rate was 4 (6%). In terms of clinical symptoms on an initial visit, fever and cough were confirmed in 66 (72%) and 37 (40%). Forty-three (47%) had no respiratory symptoms. As for radiological findings by chest CT scan, ground-glass opacities (GGO)s, peripheral distribution, bilateral lung involvements were seen in 88 (96%), 76 (83%) and 78 (85%), respectively.ConclusionIt is difficult to diagnose as COVID-19 pneumonia due to poor respiratory symptoms. Chest CT findings typically show GGO, peripheral and bilateral shadows. Patients should have chest CT performed if suspected for early diagnosis and therapeutic intervention, resulting in a favorable outcome and prevention of secondary nosocomial transmitted infection. 相似文献
3.
4.
目的克隆大花胡麻草环烯醚萜合酶基因(CgIS),并进行表达分析。方法以大花胡麻草根、茎、叶转录组中唯一的CgIS基因序列为基础,采用RT-PCR技术从大花胡麻草幼叶克隆CgIS基因,并进行组织特异性表达分析。结果大花胡麻草CgIS基因(GenBank登录号MH794270)全长1 185 bp,编码394个氨基酸;CgIS蛋白相对相对分子质量44 670,理论pI为6.17;该蛋白属于孕酮5β-还原酶(P5β-R)家族成员,可能定位于细胞质;该蛋白无信号肽,为亲水稳定蛋白,主要由α-螺旋(40.61%)和无规则卷曲(46.70%)构成;该蛋白具有SDR(短链脱氢酶/还原酶)和P5βR蛋白保守结构域;CgIS蛋白与芝麻SiIS蛋白亲缘关系最近;CgIS基因主要在叶中表达。结论克隆了CgIS基因,并对其进行表达分析,为进一步研究该基因的功能和环烯醚萜类的生物合成途径奠定基础。 相似文献
5.
Infectious laryngotracheitis is a significant respiratory disease of chickens that causes huge economic losses due to high morbidity and mortality and reduced egg production. A real-time recombinase polymerase amplification (RPA) assay was developed to accurately detect ILTV. The specific probe and primer sets were carefully designed and screened. The real-time RPA assay was carried out at 39 °C for 30 min, and results were obtained within 15 min. The results of the specificity assay showed no fluorescence signals with other avian-related viruses. The sensitivity of the assay was 1 × 102 copies/μL. The low CV value showed that the assay was reproducible. A total of 115 clinical samples were tested using the real-time RPA assay and the real-time PCR assay in parallel; the coincidence rates of the two detection methods were 100%. The results indicated that the real-time RPA assay is a specific, sensitive, rapid, and useful tool for epidemiological studies and clinical diagnosis, especially in the field and in resource-poor areas. 相似文献
6.
《中国现代医生》2020,58(2):135-138+封三
目的探讨实时剪切波弹性成像在评估拉米夫定治疗乙肝纤维化临床疗效中的作用。方法选取2017年1月~2018年1月我院收治的80例乙肝纤维化患者,根据随机数字法分为对照组和观察组,每组40例。对照组采用常规治疗,观察组在对照组的基础上给予拉米夫定进行治疗,治疗6个月。比较两组治疗前后肝功能、肝纤维化指标,利用实时剪切波弹性成像评估两组治疗前后肝脏弹性模量值及肝穿刺活检情况,并进行比较。结果两组治疗后AST、ALT、TBIL水平均明显低于治疗前,差异有统计学意义(P0.05);观察组治疗后AST、ALT、TBIL水平均明显低于对照组,差异有统计学意义(P0.05);两组治疗后HA、LN、PⅢPN-P、CL-Ⅳ水平及杨氏弹性模量值均显著低于治疗前,差异有统计学意义(P0.05);观察组治疗后HA、LN、PⅢPN-P、CL-Ⅳ水平及杨氏弹性模量值均显著低于对照组,差异有统计学意义(P0.05);与治疗前相比,两组治疗后肝穿刺活检结果均有好转,尤其是汇管区、肝小叶内炎症及肝纤维化改善明显。结论实时剪切波弹性成像作为肝脏硬度定量检测的无创性技术,可用于拉米夫定治疗乙肝纤维化临床疗效评估的重要方法。 相似文献
7.
8.
9.
实时超声引导下显微手术切除脑深部病灶 总被引:3,自引:0,他引:3
目的探讨术中超声引导在脑深部病灶显微手术中的应用价值。方法自2004年开始我们在脑深部病灶显微手术中采用实时超声引导病灶定位,指引手术中皮层入路及路径的选择,并使用术中超声影像动态了解病变位置的变化情况、手术切除的范围,利用实时影像辅助判断病变切除程度。结果28例脑深部病灶,病灶直径为1.0~5.9cm,病理诊断包括蛛网膜囊肿5例,海绵状血管瘤2例,动静脉畸形2例,肿瘤7例,脑内血肿12例。所有病例均显微镜下全切,术后28例患者均恢复良好,神经功能保存良好,无新的神经功能损害,无手术并发症。结论术中超声引导是一种简便有效的脑深部病灶定位方法,操作简便,定位准确,能够实时指引手术路径和动态了解手术切除病灶的范围,与显微神经外科配合能够有效地避免额外的手术损伤,提高手术精度。 相似文献
10.