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   32835篇
  免费   2417篇
  国内免费   54篇
耳鼻咽喉   304篇
儿科学   1176篇
妇产科学   962篇
基础医学   4262篇
口腔科学   430篇
临床医学   4322篇
内科学   5858篇
皮肤病学   471篇
神经病学   3534篇
特种医学   593篇
外国民族医学   4篇
外科学   2968篇
综合类   321篇
一般理论   45篇
预防医学   4542篇
眼科学   499篇
药学   2217篇
中国医学   23篇
肿瘤学   2775篇
  2024年   31篇
  2023年   263篇
  2022年   237篇
  2021年   1119篇
  2020年   680篇
  2019年   1039篇
  2018年   1158篇
  2017年   833篇
  2016年   981篇
  2015年   1007篇
  2014年   1333篇
  2013年   1873篇
  2012年   2741篇
  2011年   2968篇
  2010年   1550篇
  2009年   1301篇
  2008年   2379篇
  2007年   2390篇
  2006年   2182篇
  2005年   2051篇
  2004年   1828篇
  2003年   1584篇
  2002年   1598篇
  2001年   212篇
  2000年   171篇
  1999年   203篇
  1998年   308篇
  1997年   238篇
  1996年   168篇
  1995年   179篇
  1994年   128篇
  1993年   109篇
  1992年   66篇
  1991年   46篇
  1990年   48篇
  1989年   35篇
  1988年   36篇
  1987年   32篇
  1986年   32篇
  1985年   17篇
  1984年   19篇
  1983年   28篇
  1982年   24篇
  1981年   18篇
  1980年   11篇
  1979年   4篇
  1978年   5篇
  1973年   4篇
  1972年   4篇
  1942年   4篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
941.
942.
943.
944.
Factors that contribute to bone fragility in type 2 diabetes are not well understood. We assessed the effects of intensive glycemic control, thiazolidinediones (TZDs), and A1C levels on bone geometry and strength at the radius and tibia. In a substudy of the Action to Control Cardiovascular Risk in Diabetes trial, peripheral quantitative computed tomographic (pQCT) scans of the radius and tibia were obtained 2 years after randomization on 73 participants (intensive n = 35, standard n = 38). TZD use and A1C levels were measured every 4 months during the trial. Effects of intervention assignment, TZD use, and A1C on pQCT parameters were assessed in linear regression models. Intensive, compared with standard, glycemic control was associated with 1.3 % lower cortical volumetric BMD at the tibia in men (p = 0.02) but not with other pQCT parameters. In women, but not men, each additional year of TZD use was associated with an 11 % lower polar strength strain index (SSIp) at the radius (p = 0.04) and tibia (p = 0.002) in models adjusted for A1C levels. In women, each additional 1 % increase in A1C was associated with an 18 % lower SSIp at the ultradistal radius (p = 0.04) in models adjusted for TZD use. There was no consistent evidence of an effect of intensive, compared with standard, glycemic control on bone strength at the radius or tibia. In women, TZD use may reduce bone strength at these sites. Higher A1C may also be associated with lower bone strength at the radius, but not tibia, in women.  相似文献   
945.

BACKGROUND

Provider and patient reminders can be effective in increasing rates of preventive screenings and vaccinations. However, the effect of patient-directed electronic reminders is understudied.

OBJECTIVE

To determine whether providing reminders directly to patients via an electronic Personal Health Record (PHR) improved adherence to care recommendations.

DESIGN

We conducted a cluster randomized trial without blinding from 2005 to 2007 at 11 primary care practices in the Partners HealthCare system.

PARTICIPANTS

A total of 21,533 patients with access to a PHR were invited to the study, and 3,979 (18.5%) consented to enroll.

INTERVENTIONS

Patients in the intervention arm received health maintenance (HM) reminders via a secure PHR “eJournal,” which allowed them to review and update HM and family history information. Patients in the active control arm received access to an eJournal that allowed them to input and review information related to medications, allergies and diabetes management.

MAIN MEASURES

The primary outcome measure was adherence to guideline-based care recommendations.

KEY RESULTS

Intention-to-treat analysis showed that patients in the intervention arm were significantly more likely to receive mammography (48.6% vs 29.5%, p = 0.006) and influenza vaccinations (22.0% vs 14.0%, p = 0.018). No significant improvement was observed in rates of other screenings. Although Pap smear completion rates were higher in the intervention arm (41.0% vs 10.4%, p < 0.001), this finding was no longer significant after excluding women’s health clinics. Additional on-treatment analysis showed significant increases in mammography (p = 0.019) and influenza vaccination (p = 0.015) for intervention arm patients who opened an eJournal compared to control arm patients, but no differences for any measure among patients who did not open an eJournal.

CONCLUSIONS

Providing patients with HM reminders via a PHR may be effective in improving some elements of preventive care.

Electronic supplementary material

The online version of this article (doi:10.1007/s11606-011-1859-6) contains supplementary material, which is available to authorized users.KEY WORDS: health maintenance reminders, personal health record, preventive care, clinical decision support, Patient Gateway  相似文献   
946.
947.
Aims Concern about crime is a significant barrier to the establishment of methadone treatment centers (MTCs). Methadone maintenance reduces crime among those treated, but the relationship between MTCs and neighborhood crime is unknown. We evaluated crime around MTCs. Setting Baltimore City, MD, USA. Participants We evaluated crime around 13 MTCs and three types of control locations: 13 convenience stores (stores), 13 residential points and 10 general medical hospitals. Measures We collected reports of Part 1 crimes from 1 January 1999 to 31 December 2001 from the Baltimore City Police Department. Design Crimes and residential point locations were mapped electronically by street address (geocoded), and MTCs, hospitals and stores were mapped by visiting the sites with a global positioning satellite (GPS) locator. Concentric circular ‘buffers’ were drawn at 25‐m intervals up to 300 m around each site. We used Poisson regression to assess the relationship between crime counts (incidents per unit area) and distance from the site. Findings There was no significant geographic relationship between crime counts and MTCs or hospitals. A significant negative relationship (parameter estimate ?0.3127, P < 0.04) existed around stores in the daytime (7 am–7 pm), indicating higher crime counts closer to the stores. We found a significant positive relationship around residential points during daytime (0.5180, P < 0.0001) and at night (0.3303, P < 0.0001), indicating higher crime counts further away. Conclusions Methadone treatment centers, in contrast to convenience stores, are not associated geographically with crime.  相似文献   
948.
Previous studies have demonstrated that vitamin D3-mediated protection in EAE occurs only in females and is dependent on the presence of diestrus levels of 17β-estradiol (E2). To evaluate the role of estrogen receptors in vitamin D3 treatment of EAE, we compared disease severity, CNS histopathology and immunological responses in vehicle and calcitrol (1,25 dihydroxyvitamin D3) treated WT C57BL/6 mice vs. GPR30 membrane estrogen receptor (MER) knockout mice with MOG-35-55 peptide-induced EAE. Our results demonstrated that vitamin D3-mediated prevention of clinical signs, CNS cellular lesions and demyelination observed in WT mice was abrogated in GPR30-KO mice with EAE. Regulatory effects of vitamin D3 treatment that were MER dependent included increased levels of IL-10 and IL-6 secreted by MOG peptide-reactive splenocytes and increased expression of CCL5, CCR1 & CCR3 in spleen tissue. These results demonstrate for the first time that the MER is a key contributor to the E2-dependent effects of vitamin D3-mediated protection in EAE.  相似文献   
949.
Nilotinib is a second generation ABL tyrosine kinase inhibitor (TKI) that exerts major anti-leukemic effects in newly diagnosed patients with chronic myeloid leukemia (CML) as well as in most patients with imatinib-resistant CML. In freshly diagnosed patients, the anti-leukemic activity of nilotinib exceeds the efficacy of imatinib, and although long-term data for nilotinib are not available yet, the drug has recently been approved for firstline treatment of chronic phase CML in various countries. Still however, several questions concerning the optimal dose, follow-up parameters, long-term safety, and patient selection remain open. Likewise, it remains uncertain whether both Sokal low-risk and high-risk patients should receive nilotinib as frontline therapy in the future. Another question is whether nilotinib can completely eradicate CML in a subset of patients. Furthermore, it remains unclear whether and what comorbidity must be regarded as relative or absolute contra-indication for this TKI. To discuss these issues, the Austrian CML Working Group organized a series of meetings in 2010. In the current article, the outcomes from these discussions are summarized and presented together with recommendations for frontline use of TKIs in various groups of patients with CML. These recommendations should assist in daily practice as well as in the preparation and conduct of clinical trials.  相似文献   
950.
"Shotgunning" refers to the practice of one individual forcibly exhaling smoke into the mouth of another, and may increase the risk of transmission of respiratory pathogens. The extent of shotgunning among individuals with co-occurring serious mental illness and substance use is unknown. We included questions about shotgunning in an interview of 236 participants of a study testing a model to prevent and treat HIV and hepatitis. Shotgunning was common (61% [145/236]) and correlated with increased substance use severity and several high-risk behaviors. Only 8% (11/145) understood that shotgunning could transmit disease. Further research and patient education on shotgunning is warranted.  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