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   12597篇
  免费   1112篇
  国内免费   607篇
耳鼻咽喉   49篇
儿科学   220篇
妇产科学   42篇
基础医学   1632篇
口腔科学   125篇
临床医学   1638篇
内科学   2263篇
皮肤病学   176篇
神经病学   2084篇
特种医学   486篇
外国民族医学   3篇
外科学   908篇
综合类   1630篇
现状与发展   1篇
预防医学   352篇
眼科学   393篇
药学   930篇
  7篇
中国医学   746篇
肿瘤学   631篇
  2024年   39篇
  2023年   243篇
  2022年   356篇
  2021年   570篇
  2020年   544篇
  2019年   499篇
  2018年   463篇
  2017年   504篇
  2016年   477篇
  2015年   468篇
  2014年   811篇
  2013年   910篇
  2012年   693篇
  2011年   819篇
  2010年   589篇
  2009年   592篇
  2008年   540篇
  2007年   591篇
  2006年   491篇
  2005年   440篇
  2004年   340篇
  2003年   330篇
  2002年   353篇
  2001年   281篇
  2000年   228篇
  1999年   210篇
  1998年   193篇
  1997年   159篇
  1996年   158篇
  1995年   125篇
  1994年   116篇
  1993年   105篇
  1992年   103篇
  1991年   94篇
  1990年   81篇
  1989年   82篇
  1988年   54篇
  1987年   46篇
  1986年   52篇
  1985年   131篇
  1984年   95篇
  1983年   79篇
  1982年   68篇
  1981年   57篇
  1980年   41篇
  1979年   18篇
  1978年   24篇
  1977年   16篇
  1976年   12篇
  1972年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Vaccine》2019,37(31):4302-4309
Influenza A virus (IAV) vaccines in pigs generally provide homosubtypic protection but fail to prevent heterologous infections. In this pilot study, the efficacy of an intradermal pDNA vaccine composed of conserved SLA class I and class II T cell epitopes (EPITOPE) against a homosubtypic challenge was compared to an intramuscular commercial inactivated whole virus vaccine (INACT) and a heterologous prime boost approach using both vaccines. Thirty-nine IAV-free, 3-week-old pigs were randomly assigned to one of five groups including NEG-CONTROL (unvaccinated, sham-challenged), INACT-INACT-IAV (vaccinated with FluSure XP® at 4 and 7 weeks, pH1N1 challenged), EPITOPE-INACT-IAV (vaccinated with PigMatrix EDV at 4 and FluSure XP® at 7 weeks, pH1N1 challenged), EPITOPE-EPITOPE-IAV (vaccinated with PigMatrix EDV at 4 and 7 weeks, pH1N1 challenged), and a POS-CONTROL group (unvaccinated, pH1N1 challenged). The challenge was done at 9 weeks of age and pigs were necropsied at day post challenge (dpc) 5. At the time of challenge, all INACT-INACT-IAV pigs, and by dpc 5 all EPITOPE-INACT-IAV pigs were IAV seropositive. IFNγ secreting cells, recognizing vaccine epitope-specific peptides and pH1N1 challenge virus were highest in the EPITOPE-INACT-IAV pigs at challenge. Macroscopic lung lesion scores were reduced in all EPITOPE-INACT-IAV pigs while INACT-INACT-IAV pigs exhibited a bimodal distribution of low and high scores akin to naïve challenged animals. No IAV antigen in lung tissues was detected at necropsy in the EPITOPE-INACT-IAV group, which was similar to naïve unchallenged pigs and different from all other challenged groups. Results suggest that the heterologous prime boost approach using an epitope-driven DNA vaccine followed by an inactivated vaccine was effective against a homosubtypic challenge, and further exploration of this vaccine approach as a practical control measure against heterosubtypic IAV infections is warranted.  相似文献   
2.
3.
目的探究糖尿病周围神经病变患者开展中药穴位敷贴联合中药汤剂治疗的效果。方法研究时限为2017年8月—2018年11月,研究对象为此期间收治的糖尿病周围神经病变患者42例,将其随机分为常规组(21例)、中药组(21例),分别开展常规治疗、中药穴位敷贴+中药汤剂治疗,比较治疗结果。结果2组患者治疗前中医证候积分、TCSS(多伦多临床评分)相近(P>0.05),治疗后中药组患者以上评分均较常规组具鲜明优势(P<0.05);常规组患者不良反应发生率为14.3%,与中药组0.0%相比,未见鲜明差异(P>0.05)。结论予糖尿病周围神经病变患者开展中药穴位敷贴联合中药汤剂治疗,效果安全有效。  相似文献   
4.
5.
目的探讨T细胞非特异性活化在CNS脱髓鞘性疾病中的作用。方法分离实验性自身免疫性脑脊髓炎(EAE)易感性BALB/c小鼠外周血单个核细胞(PBMC),采用体外细胞培养方法在体外与碱性髓鞘蛋白(MBP)共培养,测定培养上清液中IFN-γ、NO水平。结果经MBP刺激的PBMC产生IFN-γ[(43.83±6.06)pg/mL]和NO[(180.76±20.75)μmol/L]明显增加,与对照组产生的IFN-γ[(28.52±2.18)pg/mL]和NO[(95.61±13.09)μmol/L]相比差异有统计学意义(P<0.01)。结论在CNS脱髓鞘性疾病发病过程中,活化的T细胞、单核细胞等分泌致炎细胞因子和其他有害物质增多。  相似文献   
6.
Summary. A new apparatus which measures the blood pressure in the finger continuously and yet not invasively was tested for its usefulness during exercise. It was compared with upper arm measurements in 23 volunteers during prolonged bicycle ergometry. Simultaneously, a pulse plethysmogram was recorded from another finger of the same arm, whereas in six additional volunteers Doppler measurements were carried out on the radial artery. The results show that finger systolic pressure ceased to rise at about 40% of maximal exercise; the difference with the continuously rising systolic pressure in the upper arm becoming significant at 140 W. At the same time the amplitude of the finger plethysmogram became significantly higher than its initial value, indicating distinct cutaneous vasodilation, whereas the volunteers also became hot and started to perspire. However, the radial artery ‘flow’, deduced from the Doppler measurements, did not change significantly during exercise. It increased sharply and markedly in the cooling down period. Simultaneously with this increase in flow, HR and both systolic blood pressures fell drastically whereas the plethysmography amplitude remained about stable at its raised level. The results fit in with the idea that a compromise is achieved between the need for muscle activity and the need for temperature regulation. It is concluded that the Finapres functions well during exercise, but that the systolic pressure in the finger is not representative for its more central counterpart during cutaneous vasodilation. It is argued that opening up of AVAs may contribute to this pressure effect.  相似文献   
7.
8.
目的:探讨周围血管损伤自全大隐静脉移植治疗的方法。适应证和治疗效果。方法:回顾性分析22例周围血管损伤自体大隐静脉移植治疗的临床资料,并阐述了术中注意事项,提出最佳手术时机及预后情况。结果:22例均采用自体大隐静脉移植,痊愈19例(86.4%)。截肢3例(13.6%),22例患者无死亡,随访2-9年,20例肢体功能恢复满意,2例移植段狭窄,但肢体功能良好。结论:自体大隐静脉移植是治疗周围血管损伤行之有效的方法之一。血管吻合的时间应在24h以内,最佳为8h以内。  相似文献   
9.
Abstract   We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN.  相似文献   
10.
The objective of this review is to identify and review publications describing the impact of reduced somatosensation on balance. Based on knowledge of the association between specific somatosensory loss and deterioration of balance, conclusions can be made about role of somatosensation in standing balance.A systematic literature review is presented in which publications from the years 1993 through 2007 were searched in Medline and Embase. Medical Subject Headings (MESH) terms and free text words (related to balance, somatosensory loss, and lower limb) were used to perform the searches. Fifteen articles were selected for detailed review based on predetermined inclusion criteria, and three of the included articles described the effect of experimentally reduced somatosensation on balance in healthy subjects. Ten of the articles described balance in diabetic neuropathy (DN). The last two included articles described balance in Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) or type 2 (CMT2).The literature indicates that the tactile sensation is reduced in DN, CMT1A, and CMT2 and when the plantar surface of the feet was hypothermically anesthetized. Joint motion sensation seems to be impaired in patients with DN, and passive joint position sensation appears to be reduced in healthy subjects with anesthesia of ankle and foot from prolonged ischemia. This reduced somatosensation seems to have a negative effect on balance in patients with DN and CMT2; however, this appeared not to be the case in patients with CMT1A and in healthy subjects.  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