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   35329篇
  免费   2922篇
  国内免费   596篇
耳鼻咽喉   407篇
儿科学   529篇
妇产科学   553篇
基础医学   1513篇
口腔科学   347篇
临床医学   5323篇
内科学   3382篇
皮肤病学   520篇
神经病学   1630篇
特种医学   795篇
外科学   2778篇
综合类   4988篇
一般理论   3篇
预防医学   6332篇
眼科学   430篇
药学   5120篇
  31篇
中国医学   2500篇
肿瘤学   1666篇
  2024年   93篇
  2023年   779篇
  2022年   1537篇
  2021年   1852篇
  2020年   1907篇
  2019年   1739篇
  2018年   1593篇
  2017年   1452篇
  2016年   1298篇
  2015年   1224篇
  2014年   3298篇
  2013年   2674篇
  2012年   2632篇
  2011年   2718篇
  2010年   1927篇
  2009年   1856篇
  2008年   1786篇
  2007年   1732篇
  2006年   1355篇
  2005年   1062篇
  2004年   835篇
  2003年   635篇
  2002年   452篇
  2001年   372篇
  2000年   343篇
  1999年   288篇
  1998年   198篇
  1997年   208篇
  1996年   161篇
  1995年   146篇
  1994年   118篇
  1993年   103篇
  1992年   82篇
  1991年   74篇
  1990年   50篇
  1989年   26篇
  1988年   36篇
  1987年   21篇
  1986年   18篇
  1985年   48篇
  1984年   28篇
  1983年   13篇
  1982年   22篇
  1981年   20篇
  1980年   9篇
  1979年   8篇
  1977年   4篇
  1976年   3篇
  1975年   5篇
  1970年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.

Objective

To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs.

Methods

This double-blinded, sham-controlled study enrolled 48 subjects and measured headache severity, frequency [headache days/month, number of total and mild/moderate/severe classified attacks/month], functional state [sleep, mood, body weight, migraine-associated disability] and serum levels of inflammatory markers [inter-ictal] using enzyme-linked immunoassays at baseline and after 2 months of adjunctive nVNS compared to sham stimulation and suitably matched controls.

Results

No significant differences were observed at baseline and after 2 months for headache severity, total attacks/month, headache days/month and functional outcome [sleep, mood, disability] between verum and sham nVNS. However, the number of severe attacks/month significantly decreased in the verum nVNS group and circulating pro-inflammatory IL-1β was elevated significantly in the sham group compared to nVNS. Levels of anti-inflammatory IL-10 were significantly higher at baseline in both groups compared to healthy controls, but not at 2 months follow-up [p?<?0.05]. Concentrations of high-mobility group box-1 (HMGB-1), IL-6, tumor-necrosis factor-α (TNF-α), leptin, adiponectin, ghrelin remained unchanged [p?>?0.05]. No severe device-/stimulation-related adverse events occurred.

Conclusion

2 months of adjunctive cervical nVNS significantly declined the number of severe attacks/month. Pro-inflammatory IL-1β plasma levels [inter-ictal] were higher in sham-treated migraine patients compared to verum nVNS. However, pro- [IL-6, HMGB-1, TNF-α, leptin] and anti-inflammatory [IL-10, adiponectin, ghrelin] mediators did not differ statistically. Profiling of neuroinflammatory circuits in migraine to predict nVNS responsiveness remains an experimental approach, which may be biased by pre-analytic variables warranting large-scale biobank-based systematic investigations [omics].  相似文献   
32.
33.
ObjectiveImprovement in the quality of life is reflected in the narrowing of the gap between health-adjusted life expectancy (HALE) and life expectancy (LE). The effect of megacity expansion on narrowing the gap is rarely reported. This study aimed to disclose this potential relationship.MethodsAnnual life tables were constructed from identified death records and population counts from multiple administrative sources in Guangzhou, China, from 2010 to 2020. Joinpoint regression was used to evaluate the temporal trend. Generalized principal component analysis and multilevel models were applied to examine the county-level association between the gap and social determinants.ResultsAlthough LE and HALE in megacities are increasing steadily, their gap is widening. Socio-economic and health services are guaranteed to narrow this gap. Increasing personal wealth, a growing number of newborns and healthy immigrants, high urbanization, and healthy aging have helped in narrowing this gap.ConclusionIn megacities, parallel LE and HALE growth should be highly considered to narrow their gap. Multiple social determinants need to be integrated as a whole to formulate public health plans.  相似文献   
34.
Background and Study AimsIn developing countries, endemic indications, blood shortages, and the scarcity of liver surgeons and intensive care providers can affect liver resection (LR) outcomes, but these have been rarely addressed in the literature. Therefore, in this study we determined risk factors for major complications after LR in a North African general surgery and teaching department.Patients and MethodsFrom January 2010 to December 2015, 213 consecutive LRs were performed on 203 patients. All patients underwent a postoperative follow-up of >90 days. Postoperative complications were assessed according to the Clavien–Dindo (CD) classification of surgical complications. A score of CD ≥III is considered as major postoperative complications. In this study, we analyzed the variables assumed to affect these complications.ResultsThe overall 90-day complication rate was 35.7% (n = 76), including a CD ≥III of 14% (n = 30) and a mortality rate of 6.1% (n = 14). According to the multivariate analysis, a preoperative performance status (PS) of ≥2 (P = 0.011; odds ratios [OR], 6.8; 95% confidence intervals [CI], 1.55–29.8), an estimated intraoperative blood loss of >500 ml (P = 0.002; OR, 3.71; 95% CI, 1.23–11.20), and bilioenteric anastomosis (P < 0.004; OR, 7.76; 95% CI, 1.5–3.89) were independent risk factors for major complications after LR.ConclusionWe recommend that, in the setting of a non-Eastern/non-Western general surgery and teaching department, patients with a PS of ≥2 should undergo a specific selection and preoperative optimization protocol; intermittent clamping indications should be extended; and special attention should paid to patients undergoing LR associated with biliary reconstruction, such as for perihilar cholangiocarcinoma.  相似文献   
35.
36.
37.
BackgroundThere is an urgent need to empower practitioners to undertake quality improvement (QI) projects in burn services in low-middle income countries (LMICs). We piloted a course aimed to equip nurses working in these environments with the knowledge and skills to undertake such projects.MethodsEight nurses from five burns services across Malawi and Ethiopia took part in this pilot course, which was evaluated using a range of methods, including interviews and focus group discussions.ResultsCourse evaluations reported that interactive activities were successful in supporting participants to devise QI projects. Appropriate online platforms were integral to creating a community of practice and maintaining engagement. Facilitators to a successful QI project were active individuals, supportive leadership, collaboration, effective knowledge sharing and demonstrable advantages of any proposed change. Barriers included: staff attitudes, poor leadership, negative culture towards training, resource limitations, staff rotation and poor access to information to guide practice.ConclusionsThe course demonstrated that by bringing nurses together, through interactive teaching and online forums, a supportive community of practice can be created. Future work will include investigating ways to scale up access to the course so staff can be supported to initiate and lead quality improvement in LMIC burn services.  相似文献   
38.
39.
《Clinical neurophysiology》2019,130(9):1562-1569
ObjectiveConventional deep brain stimulation (DBS) systems with ring-shaped leads generate spherical electrical fields. In contrast, novel directional leads use segmented electrodes. Aim of this study was to quantify the impedance variations over time in subjects with the directional Cartesia-Boston® system.MethodsImpedance records, programming settings, and clinical data of 11 consecutive Parkinsonian patients implanted with DBS directional leads in two Italian centers (Udine and Vicenza) were retrospectively evaluated. Data were collected before starting stimulation (in the operating room and at days 5 and 40) and after switching stimulation on at the successive follow-up visits (1, 6 and 12 months).ResultsDirectional leads have significantly higher impedance than ring leads. Stimulated contacts had always lower impedance compared to non-stimulated contacts. Before DBS-on, all contacts had higher impedance in the operating room, with an initial decrease five days post-surgery and a subsequent increase at day 40, more evident for directional contacts. The impedance of directional leads increased post-implantation at 1 and 6 months with a plateau at 12 months.ConclusionsThere was a significant difference between the directional and ring leads at baseline (before activation of DBS) and during follow-up (chronic DBS).SignificanceOur study reveals new information about the impedance of segmented electrodes that is useful for patient management during the initial test period, as well as during long-term DBS follow-up.  相似文献   
40.
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