首页 | 官方网站   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   37188篇
  免费   3072篇
  国内免费   786篇
医药卫生   41046篇
  2023年   974篇
  2022年   1446篇
  2021年   2150篇
  2020年   1696篇
  2019年   2062篇
  2018年   2123篇
  2017年   1759篇
  2016年   1420篇
  2015年   1557篇
  2014年   2649篇
  2013年   2856篇
  2012年   2048篇
  2011年   2276篇
  2010年   1716篇
  2009年   1743篇
  2008年   1640篇
  2007年   1569篇
  2006年   1265篇
  2005年   1042篇
  2004年   965篇
  2003年   789篇
  2002年   546篇
  2001年   552篇
  2000年   472篇
  1999年   450篇
  1998年   332篇
  1997年   327篇
  1996年   290篇
  1995年   223篇
  1994年   216篇
  1993年   170篇
  1992年   119篇
  1991年   113篇
  1990年   99篇
  1989年   120篇
  1988年   84篇
  1987年   76篇
  1986年   69篇
  1985年   151篇
  1984年   152篇
  1983年   111篇
  1982年   142篇
  1981年   97篇
  1980年   83篇
  1979年   79篇
  1978年   53篇
  1977年   32篇
  1976年   35篇
  1975年   27篇
  1974年   28篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
71.
72.
Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and presents together with cirrhosis in most cases. In addition to commonly recognized risk factors for HCC development, such as hepatitis B virus/hepatitis C virus infection, age and alcohol/tobacco consumption, there are nutritional risk factors also related to HCC development including high intake of saturated fats derived from red meat, type of cooking (generation of heterocyclic amines) and contamination of foods with aflatoxins. On the contrary, protective nutritional factors include diets rich in fiber, fruits and vegetables, n-3 polyunsaturated fatty acids and coffee. While the patient is being evaluated for staging and treatment of HCC, special attention should be paid to nutritional support, including proper nutritional assessment and therapy by a multidisciplinary team. It must be considered that these patients usually develop HCC on top of long-lasting cirrhosis, and therefore they could present with severe malnutrition. Cirrhosis-related complications should be properly addressed and considered for nutritional care. In addition to traditional methods, functional testing, phase angle and computed tomography scan derived skeletal muscle index-L3 are among the most useful tools for nutritional assessment. Nutritional therapy should be centered on providing enough energy and protein to manage the increased requirements of both cirrhosis and cancer. Supplementation with branched-chain amino acids is also recommended as it improves response to treatment, nutritional status and survival, and finally physical exercise must be encouraged and adapted to individual needs.  相似文献   
73.
背景与目的:恶性肿瘤是全球重大的公共健康问题,患者生存率是评价恶性肿瘤诊治水平的重要指标。通过描述以医院登记为基础的20万例恶性肿瘤患者的生存情况,以真实世界数据从一个侧面反映我国恶性肿瘤的治疗效果。方法:纳入2008年1月1日—2017年12月31日之间在复旦大学附属肿瘤医院确诊为恶性肿瘤并接受住院治疗的患者共计202 542例。通过患者复诊病史资料、电话随访及死因数据链接等方式收集生存随访信息,随访统计时间截至2019年11月30日。应用寿命表法估计各个病种1年、3年和5年总生存率(overall survival,OS),以性别、年龄组、首次治疗时间分层。采用Kaplan-Meier生存曲线绘制各病种的总体生存曲线。结果:患者总体的1年、3年、5年OS分别为89.8%、77.4%和71.0%;男性患者5年OS为58.8%,女性患者为78.7%。在常见的恶性肿瘤中,甲状腺癌患者的5年OS最高,为98.6%;胰腺癌患者最低,为11.4%。2013—2017年首次治疗的乳腺癌、肺癌和肾癌患者5年OS分别为90.0%、55.9%和80.7%,显著高于2008—2012年首次治疗患者,其他肿瘤未见显著上升。结论:大部分恶性肿瘤患者经规范诊治可以获得较为理想的预后,女性生存情况显著优于男性,乳腺癌和肺癌患者的生存改善可能归功于新的临床治疗和早诊手段。  相似文献   
74.
BackgroundMany patients with erectile dysfunction (ED) after radical prostatectomy (RP) improve with conservative therapy but some do not; penile prosthesis implantation rates have been sparsely reported, and have used nonrepresentative data sets.AimTo characterize rates and timing of penile prosthesis implantation after RP and to identify predictors of implantation using a more representative data set.MethodsThe Healthcare Cost and Utilization Project State Inpatient and State Ambulatory Surgery databases for Florida from 2006 to 2015 were used. Patients undergoing RP (2006–2012) were tracked longitudinally for penile prosthesis implantation. Patient and clinical data were analyzed using multivariable logistic regression.OutcomesThe primary outcome was risk-adjusted predictors of prosthesis implantation, and the secondary outcome was predictors of the highest quartile of time between RP and penile prosthesis.ResultsOf 29,288 men who had RP, 1,449 (4.9%) patients underwent subsequent prosthesis. The mean time from RP to prosthesis was 2.6 years (median: 2.1; interquartile range [IQR]: 1.2–3.5). Adjusted predictors of prosthesis implantation included open RP (odds ratio [OR]: 1.5, P < .01), African American race (OR: 1.7, P < .01) or Hispanic ethnicity (OR: 3.2, P < .01), and Medicare (OR: 1.4, P < .01) insurance. Oler patients (age >70 years; OR: 0.7, P < .01) and those from the highest income quartile relative to the lowest (OR: 0.8, P < .05) were less likely to be implanted. Adjusted predictors of longer RP-to-implantation time (highest quartile: median: 4.7 years; IQR: 3.9–6.0 years) included open RP (OR: 1.78, P < .01), laparoscopic RP (OR: 4.67, P < .01), Medicaid (OR: 3.03, P < .05), private insurance (OR: 2.57, P < .01), and being in the highest income quartile (OR: 2.52, P < .01).Clinical ImplicationsThese findings suggest ED treatment healthcare disparities meriting further investigation; upfront counseling on all ED treatment modalities and close monitoring for conservative treatment failure may reduce lost quality of life years.Strengths & LimitationsThis study is limited by its use of administrative data, which relies on accurate coding and lacks data on ED questionnaires/prior treatments, patient-level cost, and oncologic outcomes. Quartile-based analysis of income and time between RP and prosthesis limits the conclusions that can be drawn.ConclusionLess than 5% of post-RP patients undergo penile prosthesis implantation, with open RP, Medicare, African American race, and Hispanic ethnicity predicting post-RP implantation; living in the wealthiest residential areas predicts lower likelihood of implantation compared to the least wealthy areas. Patients with the longest time between RP and prosthesis are more likely to live in the wealthiest areas or have undergone open/laparoscopic RP relative to robotic RP.Bajic P, Patel PM, Nelson MH, et al. Penile Prosthesis Implantation and Timing Disparities After Radical Prostatectomy: Results From a Statewide Claims Database. J Sex Med 2020;17:1175–1181.  相似文献   
75.
《Vaccine》2016,34(45):5436-5441
Influenza is a viral infection that affects much of the global population each year. Vaccination remains the most effective tool for preventing the disease. Live attenuated influenza vaccine (LAIV) has been used since the 1950s to protect humans against seasonal influenza. LAIVs developed by the Institute of Experimental Medicine (IEM), Saint Petersburg, Russia, have been successfully used in Russia since 1987.In 2006, the World Health Organization (WHO) announced a Global action plan for influenza vaccines (GAP). WHO, recognizing potential advantages of LAIV over the inactivated influenza vaccine in a pandemic situation, included LAIV in the GAP.BioDiem Ltd., a vaccine development company based in Melbourne, Australia which held the rights for the Russian LAIV, licensed this technology to WHO in 2009. WHO was permitted to grant sub-licenses to vaccine manufacturers in newly industrialized and developing countries to use the Russian LAIV for the development, manufacture, use and sale of pandemic and seasonal LAIVs. To date, WHO has granted sub-licenses to vaccine manufacturers in China (Changchun BCHT Biotechnology Co., Ltd.), India (Serum Institute of India Pvt. Ltd.) and Thailand (Government Pharmaceutical Organization). In parallel, in 2009, IEM signed an agreement with WHO, under which IEM committed to supply pandemic and seasonal candidate vaccine viruses to the sub-licensees.This paper describes the progress made by collaborators from China, India, Russia and Thailand in developing preventive measures, including LAIV against pandemic influenza.  相似文献   
76.
《Vaccine》2016,34(29):3396-3404
Francisella tularensis (Ft) is a Category A biothreat agent for which there currently is no FDA-approved vaccine. Thus, there is a substantial effort underway to develop an effective tularemia vaccine. While it is well established that gender can significantly impact susceptibility to primary infection, the impact of gender on vaccine efficacy is not well established. Thus, development of a successful vaccine against tularemia will require an understanding of the impact gender has on vaccine-induced protection against this organism. In this study, a role for gender in vaccine-induced protection following Ft challenge is identified for the first time. In the present study, mucosal vaccination with inactivated Ft (iFt) LVS elicited gender-based protection in C57BL/6Tac mice against respiratory challenge with Ft LVS. Specifically, vaccinated male mice were more susceptible to subsequent Ft LVS challenge. This increased susceptibility in male mice correlated with increased bacterial burden, increased tissue inflammation, and increased proinflammatory cytokine production late in post-challenge infection. In contrast, improved survival of iFt-vaccinated female mice correlated with reduced bacterial burden and enhanced levels of Ft-specific Abs in serum and broncho-alveolar lavage (BAL) fluid post-challenge. Furthermore, vaccination with a live attenuated vaccine consisting of an Ft LVS superoxide dismutase (SodB) mutant, which has proven efficacious against the highly virulent Ft SchuS4 strain, demonstrated similar gender bias in protection post-Ft SchuS4 challenge. Of particular significance is the fact that these are the first studies to demonstrate that gender differences impact disease outcome in the case of lethal respiratory tularemia following mucosal vaccination. In addition, these studies further emphasize the fact that gender differences must be a serious consideration in any future tularemia vaccine development studies.  相似文献   
77.
《Vaccine》2020,38(33):5337-5342
Freezing of alum-based vaccines drastically alters their colloidal composition and leads to irreversible cluster formation. The loss of stability is well described, but the impact of frost damage on the functionality of the induced and secreted antibody repertoire has not been studied in detail. We therefore applied our single-cell measurement platform to extract the frequencies of Immunoglobulin G-secreting cells in combination with individual secretion rates and affinities. We showed that, frost-damaged or not, the tested vaccine was able to generate similar frequencies of total and antigen-affine IgG-secreting cells. Additionally, the frost-damaged vaccine stimulated a similar T-cell cytokine secretion pattern when compared to the regularly stored vaccine. However, frost-damaged vaccines induced no efficient affinity maturation and a complete collapse of the affinity distribution was observed. This study unveiled the impact of frost-damage to alum-based vaccines on the induced secreted antibody repertoire, and illustrated the power of functional single-antibody analysis.  相似文献   
78.
背景与目的:结直肠癌(colorectal cancer,CRC)为世界第三常见恶性肿瘤,近年来研究者认为白细胞介素(interleukin,IL)-35和(或)IL-37与CRC的发展有关,但其作用机制尚未阐明。探究IL-35和IL-37在CRC发展中的作用及其可能的机制,分析IL-35和IL-37与CRC患者预后的相关性。方法:收集2013年—2017年在上海交通大学医学院附属同仁医院接受治疗的191例CRC患者手术病理蜡块的肿瘤组织,与其匹配的非癌组织是来源于同一患者的肠癌手术切缘蜡块组织。应用免疫组织化学(immunohistochemistry,IHC)染色法将CRC患者的癌组织与非癌组织染色,并运用Image-Pro Plus将IHC染色阳性部分定量分析,结合随访结果,探讨癌组织与非癌组织中IL-35和IL-37的表达水平与CRC临床病理学特征及预后的相关性。结果:与非癌组织相比,CRC组织中IL-35的表达量减少了50%(P<0.000 1)。CRC组织中IL-37的表达量与非癌组织相比增加了40%(P=0.012)。多因素生存分析显示,癌组织中IL-35(HR=0.39;95% CI:0.16~0.97;P=0.04)的表达水平是CRC患者术后生存的独立预测指标。结论:IL-35和IL-37蛋白的表达水平可能与CRC的发展有关,IL-35的表达水平可能是CRC患者术后生存的独立预测指标。  相似文献   
79.
80.
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-23

京公网安备 11010802026262号