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   2881篇
  免费   158篇
  国内免费   14篇
耳鼻咽喉   21篇
儿科学   30篇
妇产科学   30篇
基础医学   348篇
口腔科学   6篇
临床医学   137篇
内科学   81篇
皮肤病学   10篇
神经病学   1623篇
特种医学   16篇
外科学   152篇
综合类   214篇
预防医学   58篇
眼科学   24篇
药学   278篇
中国医学   13篇
肿瘤学   12篇
  2024年   3篇
  2023年   32篇
  2022年   47篇
  2021年   84篇
  2020年   88篇
  2019年   68篇
  2018年   94篇
  2017年   116篇
  2016年   136篇
  2015年   119篇
  2014年   184篇
  2013年   329篇
  2012年   159篇
  2011年   229篇
  2010年   162篇
  2009年   173篇
  2008年   168篇
  2007年   153篇
  2006年   106篇
  2005年   92篇
  2004年   75篇
  2003年   78篇
  2002年   53篇
  2001年   47篇
  2000年   29篇
  1999年   19篇
  1998年   22篇
  1997年   11篇
  1996年   10篇
  1995年   16篇
  1994年   9篇
  1993年   7篇
  1992年   12篇
  1991年   5篇
  1990年   11篇
  1989年   7篇
  1988年   12篇
  1987年   7篇
  1986年   6篇
  1985年   17篇
  1984年   10篇
  1983年   13篇
  1982年   6篇
  1981年   6篇
  1980年   4篇
  1979年   8篇
  1978年   5篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
排序方式: 共有3053条查询结果,搜索用时 31 毫秒
1.
ObjectivesTo analyze the effect of indigenous bicentric bipolar prosthesis on horizontal and vertical offsets in fracture neck of femur when compared to contralateral normal hip and to evaluate functional outcomes. We hypothesized that our non-modular bipolar device restores satisfactory offsets in such patients.MethodsAll active elderly patients with displaced fracture NOF having contralateral normal hip were included. We used an indigenous bicentric bipolar hip-prosthesis, which is a non-modular single-piece device in all cases by lateral Hardinge approach. Postoperative radiograph AP view was taken in 15° internal rotation to decrease the effect of limb rotation on offset. CT scan was also used to evaluate offsets using ADW4.6 ADVANCED GE optima 128 slice software system. Subjects were followed for a minimum of 12 months postoperatively and functional outcome of effect of offsets change were evaluated by modified Harris Hip Score.ResultsThere is minimal difference in horizontal and vertical offset after bicentric bipolar hemi-replacement which is statistically insignificant supporting our hypothesis. The clinical outcomes were good to fair according to modified Harris Hip Score. The mean value of horizontal offset after our bipolar hemireplacement was 42.4 ± 2.04 mm and of normal hip was 41.8 ± 1.81 mm and P-value=0.08 in plain radiographs and value of horizontal offset in CT scan was 40.73 ± 0.27on bipolar side and 41.19 ± 0.77 on normal side. Vertical offset after bicentric bipolar was 32.67 ± 2.85 mm and vertical offset of normal hip was 32.53 ± 2.73 mm. Mean 9.77 ± 1.09 mm of calcar was preserved. Modified Harris Hip Score at 6 and 12 months postoperatively was 75.78 ± 4.16 and 79.53 ± 3.95 respectively. There was no incidence of hip dislocation.ConclusionOur study data clearly demonstrates that vertical and horizontal offsets are effectively maintained by the indigenous bicentric hip device. There was insignificant change in offsets as compared to contralateral normal side due to its design modifications. Indigenous bicentric non-modular bipolar device offers an excellent option for femur neck fractures in elderly patients in resource constrained situations. It allows rapid rehabilitation due to reduced surgical time, minimal blood loss and early return to function and activities of daily living.  相似文献   
2.
ObjectiveAn aberrant gut microbiota may be associated with a broad spectrum of diseases including mental illness. The gut microbiota is scarcely studied in bipolar disorder (BD). We examined the gut microbiota composition in patients with newly diagnosed BD, their unaffected first-degree relatives and healthy individuals.MethodsStool samples were collected from 113 patients with BD, 39 unaffected first-degree relatives and 77 healthy individuals and the microbiota was profiled using 16S rRNA gene amplicon sequencing.ResultsThe gut microbiota community membership of patients with BD differed from that of healthy individuals (R2 = 1.0%, P = 0.008), whereas the community membership of unaffected first-degree relatives did not. Flavonifractor was present in 61% of patients with BD, 42% of their unaffected relatives and 39% of healthy individuals. Presence of Flavonifractor was associated with an odds ratio of 2.9 (95%CI: 1.6–5.2, P = 5.8 × 10−4, Q = 0.036) for having BD. When excluding smokers, presence of Flavonifractor was associated with an odds ratio of 2.3 (95%CI: 1.1–5.3, P = 0.019) for having BD. However, when considering the subsample of non-smokers only, BD and presence of Flavonifractor were no longer associated when adjusted for all possible tests at genus level (Q = 0.6). Presence of Flavonifractor in patients with BD was associated with smoking and female sex, but not with age, waist circumference, exercise level, high-sensitive C-reactive protein, current affective state, subtype of BD, illness duration or psychotropic medication, respectively.ConclusionFlavonifractor, a bacterial genus that may induce oxidative stress and inflammation in its host, was associated with BD. Higher prevalence of smoking among patients with BD contributed to our findings, and it cannot be excluded that findings are influenced by residual confounding.  相似文献   
3.

Objective

Major depressive disorder (MDD) is a prevalent condition in older adults. Although antidepressant drugs are commonly prescribed, efficacy is variable, and older patients are more prone to side effects. Repetitive transcranial magnetic stimulation (rTMS) is an alternative therapy used increasingly in the treatment of MDD. Even though recent studies have shown efficacy of rTMS in elderly depressed patients, the safety and efficacy of accelerated rTMS has not been studied in this population.

Methods

Data were retrospectively analyzed for adults with treatment-resistant depression (N?=?73, n?=?19 ≥60years, n?=?54 <60 years) who underwent an accelerated protocol of 30 sessions (2 sessions per day) of left dorsolateral prefrontal cortex high-frequency (20 Hz) rTMS.

Results

There were statistically significant improvements in depression and anxiety symptoms from baseline to post-treatment in both age groups, but those 60years and older showed statistically greater improvement in depression and anxiety symptom scores (p?=?0.01) than those less than 60. There were significantly more responders (p?=?0.001) and remitters (p?=?0.023) in the older group. The age groups did not differ significantly in clinical and demographic characteristics or severity of current depressive episode, although baseline anxiety was less severe in those 60years and older. Unipolar and bipolar patients had a similar clinical response, and treatment appeared to be well tolerated by all patients.

Conclusion

Our results suggest that accelerated rTMS protocol is a safe and effective treatment for unipolar and bipolar depressed subjects, including older adults.  相似文献   
4.
《L'Encéphale》2019,45(6):530-532
IntroductionThe objective of this paper is to verify if traits and symptoms defined as pathological and maladjusted in certain contexts may produce adaptive effects in other contexts, especially if they occur in sub-threshold forms.MethodsA historical examination of how the symptoms of depression have changed in front of great social changes and an analysis of Sardinian migrants’ thymic profiles toward several metropolises.Results and conclusionsMood disorders have been increasing since the “English malady” in the 17th century, and we suppose that some forms of mood disorders might have an adaptive advantage. Otherwise, the increase of such an epidemic would have been self-limited. From a sociobiological point of view, it is highly probable that the environment of a rapidly evolving society can select people who are explorers and able to support accelerated biorhythms and that the condition of social change stimulates psychological and psychopathologic changes. It is also possible that hyperthymic persons modulate and create the new environment. If this model can explain the epidemic of mood disorders, its verification should guide future research.  相似文献   
5.
《Brain stimulation》2020,13(1):15-19
BackgroundLithium is a helpful adjunct to patients undergoing ECT. However, only case reports and limited data suggest increase risk of delirium. Thus, this continues to be a controversial issue.ObjectiveIn this study, we examine 1) The association and odds of delirium and cognitive problems with ECT and lithium (ECT + Li) combination compared to ECT alone, 2) If positively associated, would this association vary by both type of mood episode and type of disorder?MethodsA national sample of 64,728 adult psychiatric inpatients across the US (identified from a total data of about 70 million total discharges annually) was analyzed using linear-by-linear association and logistic regression to assess the odds ratio (OR) for delirium and cognitive impairment for those treated with lithium (N = 158), ECT (N = 64148), or ECT + Li (N = 422) after adjusting for demographics and psychiatric diagnoses.ResultsThe prevalence of delirium was higher in the ECT + Lithium group (5.7%) vs. ECT only (0.6%) or lithium only groups (0%). Patients managed with ECT + Lithium have 11.7-fold higher odds (95% CI 7.55–17.99, P < 0.001) of delirium compared to ECT alone. In the ECT + Li group, delirium prevalence was 7.8% in unipolar depression, 3.4% in bipolar depressed, 0% in bipolar mania.ConclusionThese results are surprising given the fading concern about delirium association with ECT + lithium combination. The high odds in the combination group warrant clinical caution, use of lower lithium doses (if combinations cannot be avoided), and vigilance regarding early signs of delirium. These results warrant replication in future studies.  相似文献   
6.
目的 探讨儿童双相情感障碍经不同药物方案治疗后代谢指标的变化及治疗疗效。方法 回顾性分析2017年1月至2020年1月于该院就诊的220例儿童双相情感障碍患儿的临床资料。根据治疗方法分组,单纯采用非典型抗精神病药物治疗的112例患儿纳入对照组,采用非典型抗精神病药物联合心境稳定剂治疗的108例患儿纳入研究组。比较两组基线资料水平,治疗前后代谢指标空腹胰岛素(FIN)、糖化血红蛋白(HbAlc)、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平变化,以及代谢综合征发生情况及临床疗效。结果 两组患儿年龄、性别、病程等基线资料比较差异均无统计学意义(P > 0.05)。研究组总有效率为92.6%,高于对照组(82.1%,P < 0.05)。治疗前,两组FIN、HbAlc水平比较差异无统计学意义(P > 0.05);治疗后,对照组FIN水平高于治疗前,且高于研究组(P < 0.05);但研究组治疗前后FIN水平比较差异无统计学意义(P > 0.05);两组治疗前后HbAlc水平比较差异无统计学意义(P > 0.05)。治疗前,两组TC、TG、HDL-C、LDL-C水平比较,差异无统计学意义(P > 0.05);治疗后,对照组TC、TG水平均高于治疗前,且高于研究组(P < 0.05);但研究组治疗前后TC、TG水平比较差异无统计学意义(P > 0.05);两组治疗前后HDL-C、LDL-C水平比较差异无统计学意义(P > 0.05)。研究组代谢综合征发生率(2.8%)低于对照组(9.8%)(P < 0.05)。结论 儿童双相情感障碍采用非经典抗精神病药物联合心境稳定剂治疗对代谢指标水平影响较小,且疗效显著。  相似文献   
7.
8.
Bipolar clavicular dislocation is rare, and therefore its management is contentious. With an increase of patient’s physical demand and a near-normal shoulder function, there has been a shift in the paradigm of its management from a conservative one to a stabilized one of anatomical open reduction. Proposed methods of fixation have also evolved with the advent of more biological fixation devices, which elude implant or fixation related complications. This case report highlights the salient features of this rare case and details the management options along with the benefits of biological anatomical repair and reconstruction.  相似文献   
9.
目的探讨抑郁期双相障碍患者脑白质纤维束的变化。方法选取42例未用药双相障碍抑郁期患者(患者组)和年龄、性别及右利手与之相匹配的59名对照者(对照组)进行DTI检查,根据约翰霍普金斯大学人类白质纤维束图谱,将大脑白质组织分割为20条公认存在的粗大纤维束,应用PANDA软件计算每个被试者每条白质纤维束的4项平均弥散属性,采用非参数置换检验比较2组在20条白质纤维束上弥散指标的差异,将差异有统计学意义的脑白质纤维束弥散指标与临床指标进行Pearson相关分析。结果患者组左侧钩束各向异性分数(fractional anisotropy,FA)值低于对照组(0.40±0.01与0.41±0.01,P=0.001);胼胝体辐射线额部FA值低于对照组(0.36±0.02与0.38±0.02,P<0.001);左侧钩束径向弥散率(radial diffusivity,RD)值高于对照组(6.57×10^-4±2.41×10^-5与6.40×10^-4±2.42×10^-5,P=0.0017)。Pearson相关分析显示,2组弥散指标差异有统计学意义的白质纤维束与临床指标之间均无相关性。结论抑郁期双相障碍患者钩束及胼胝体辐射线额部存在脑白质完整性破坏。  相似文献   
10.
本文目的是探讨双相障碍社会功能和认知功能的特点及其影响因素,为临床识别与干预提供参考。研究显示,双相障碍功能损害显著,即使在稳定期,双相障碍患者仍存在不同程度的认知功能和社会功能损害,双相障碍的功能损害可能存在病理心理机制和相关影响因素。本文从双相障碍社会功能损害、认知功能损害和二者的关系等方面进行阐述,并总结当前研究的不足之处。  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