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   985篇
  免费   60篇
  国内免费   7篇
耳鼻咽喉   9篇
儿科学   24篇
妇产科学   21篇
基础医学   200篇
口腔科学   17篇
临床医学   68篇
内科学   218篇
皮肤病学   6篇
神经病学   63篇
特种医学   9篇
外科学   178篇
综合类   3篇
预防医学   80篇
眼科学   78篇
药学   55篇
肿瘤学   23篇
  2023年   7篇
  2022年   10篇
  2021年   15篇
  2020年   12篇
  2019年   6篇
  2018年   13篇
  2017年   18篇
  2016年   23篇
  2015年   16篇
  2014年   25篇
  2013年   31篇
  2012年   59篇
  2011年   62篇
  2010年   33篇
  2009年   41篇
  2008年   56篇
  2007年   64篇
  2006年   50篇
  2005年   50篇
  2004年   55篇
  2003年   51篇
  2002年   59篇
  2001年   23篇
  2000年   15篇
  1999年   15篇
  1998年   7篇
  1997年   10篇
  1996年   5篇
  1995年   10篇
  1994年   6篇
  1993年   11篇
  1992年   6篇
  1991年   15篇
  1990年   9篇
  1989年   11篇
  1988年   10篇
  1987年   9篇
  1986年   13篇
  1985年   15篇
  1984年   8篇
  1982年   8篇
  1979年   9篇
  1977年   6篇
  1976年   5篇
  1974年   5篇
  1973年   9篇
  1968年   7篇
  1966年   4篇
  1933年   4篇
  1932年   7篇
排序方式: 共有1052条查询结果,搜索用时 15 毫秒
91.

Background

Suicide is a statistically rare event, but devastating to those left behind and one of the worst possible outcomes associated with mental illness. Although a friend, family member or co-worker may be the first person to notice that a person is highly distressed, few have the knowledge and skills required to assist. Simple guidelines may help such a person to encourage a suicidal individual to seek professional help or decide against suicide.

Methods

This research was conducted using the Delphi methodology, a method of reaching consensus in a panel of experts. Experts recruited to the panels included 22 professionals, 10 people who had been suicidal in the past and 6 carers of people who had been suicidal in the past. Statements about how to assist someone who is thinking about suicide were sourced through a systematic search of both professional and lay literature. The guidelines were written using the items most consistently endorsed by all three panels.

Results

Of 114 statements presented to the panels, 30 were accepted. These statements were used to develop the guidelines appended to this paper.

Conclusion

There are a number of actions which are considered to be useful for members of the public when they encounter someone who is experiencing suicidal thoughts or engaging in suicidal behaviour. These guidelines will be useful in revision of curricula of mental health first aid and suicide intervention training programs. They can also be used by members of the public who want immediate information about how to assist a suicidal person.  相似文献   
92.
OBJECTIVE: To assess whether the recently discovered exosome-associated proteins MPP6, C1D, KIAA0052/hMtr4, hSki2, and hSki8 are targeted by autoantibodies, and to determine whether these autoantibodies are accompanied by antibodies directed to the established exosome-associated autoantigens PM-Scl-75 and PM-Scl-100. METHODS: Complementary DNAs encoding the recently identified human exosome-associated proteins were expressed as His-tagged fusion proteins in Escherichia coli cells. Sera obtained from patients with several different autoimmune diseases were analyzed for the presence of autoantibodies directed to these proteins, in an enzyme-linked immunosorbent assay (ELISA). The ELISA data obtained for C1D were confirmed by Western blot analysis, using recombinant C1D. RESULTS: All exosome-associated proteins were found to be targeted by autoantibodies, although the frequency with which such antibodies occurred in patient sera was relatively low, with the exception of anti-C1D antibodies. Autoantibodies recognizing C1D were detected in 7 of 30 patients (23%) with the polymyositis (PM)-scleroderma overlap syndrome; this frequency was similar to the frequencies for the established autoantigens PM-Scl-75c (27%) and PM-Scl-100 (23%). Importantly, several patients with the PM-scleroderma overlap syndrome had anti-C1D antibodies but no anti-PM-Scl antibodies. Anti-C1D autoantibodies were observed in only 2 of 204 patients with other diseases, including PM, dermatomyositis, and scleroderma. CONCLUSION: Our results demonstrate that the recently identified exosome-associated protein C1D is a major autoantigen in patients with the PM-scleroderma overlap syndrome and suggest that the use of recombinant C1D as an autoantibody target may aid in diagnosis of the PM-scleroderma overlap syndrome.  相似文献   
93.
OBJECTIVE: The development of heart failure is invariably associated with extensive fibrosis. Treatment with Peroxisome Proliferator-Activated Receptor (PPAR) ligands has been shown to attenuate cardiac fibrosis, but the molecular mechanism underlying this protective effect has remained largely unknown. In this study the potential of each PPAR isoform (PPARalpha, delta, and gamma) to attenuate cardiac fibroblast proliferation, fibroblast (CF) to myofibroblast (CMF) transdifferentiation, and collagen synthesis was investigated. METHODS AND RESULTS: PPARdelta was found to be the most abundant isoform in both CF and CMF. Only the PPARdelta ligand GW501516, but not PPARalpha ligand Wy-14,643 or PPARgamma ligand rosiglitazone, significantly increased PPAR-dependent promoter activity and expression of the PPAR-responsive gene UCP2 ( approximately 5-fold). GW501516 reduced the proliferation rate of CF (-38%) and CMF (-26%), which was associated with increased expression of the cell cycle inhibitor gene G0/G1 switch gene 2 (G0S2). Exposure of CF to the PPARdelta ligand or adenoviral overexpression of PPARdelta significantly decreased alpha-smooth muscle actin (alpha-SMA) levels, indicating a reduced CF to CMF transition. The inhibition of transdifferentiation by PPARdelta correlated with an increase in PTEN (Phosphatase and Tensin Homolog Deleted on Chromosome ten) expression. (3)H-Proline incorporation assays demonstrated a GW501516 induced decline in collagen synthesis (-36%) in CF. CONCLUSION: Cardiac fibroblast proliferation, fibroblast to myofibroblast differentiation and collagen synthesis were reduced after activation of PPARdelta, suggesting that PPARdelta represents an attractive molecular target for attenuating cardiac fibrosis.  相似文献   
94.
95.

Background

It is unclear whether the patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 C-to-G single nucleotide polymorphism, resulting in the substitution of isoleucine to methionine at position 148 (I148M), impedes regression of hepatic steatosis when treating non-alcoholic fatty liver disease (NAFLD).

Objectives

Investigate if carriage of the PNPLA3 148M allele affects the anti-steatotic efficacy of all possible anti-NAFLD interventions, identify gaps in current knowledge and provide guidance for individual treatment.

Methods

Research available in public databases was searched up to 13 November 2022. Studies were included if a treatment in NAFLD patients decreased hepatic steatosis in the pooled patient group or a PNPLA3 I148M polymorphism subgroup (II/IM/MM). The risk of bias was assessed using the Cochrane Risk-Of-Bias 2 Tool and the Newcastle–Ottawa Scale.

Results

Moderate evidence indicates that NAFLD patients homozygous for the PNPLA3 148M allele benefit less or not at all from omega-3 carboxylic acids to decrease liver fat, while the PNPLA3 148I allele shows moderate benefit. Low evidence suggests that interventions employing lifestyle changes are more effective to reduce liver fat in NAFLD patients homozygous for the PNPLA3 148M allele compared to patients with wild-type PNPLA3.

Conclusions

NAFLD patients homozygous for the PNPLA3 148M allele might not benefit from omega-3 carboxylic acids to reduce hepatic steatosis in contrast to patients with wild-type PNPLA3. Instead, patients with two PNPLA3 148M alleles should be especially advised to adopt lifestyle changes. Genotyping for PNPLA3 I148M should be encouraged in therapeutic studies for NAFLD.

Registration Number (Prospero)

CRD42022375028.  相似文献   
96.
97.
98.

Objective

Binge-eating disorder (BED) and bulimia nervosa (BN) are characterised by binge eating. Changing unwanted behaviour is difficult, as intentions do not automatically lead to action. Implementation intentions (IIs) may help bridging the gap between intentions and behaviour. IIs are ‘if-then’ plans promoting goal attainment. Effects are moderated by degree of plan formation. Using mental imagery (MI) to impress IIs may strengthen plan formation and goal attainment.

Method

In a students' sample with subjective binge eating, we compared IIs without MI, IIs with MI, and a control condition regarding their ability to reduce binge eating. Participants received three II-sessions and kept food diaries for 4 weeks.

Results

Results showed a significant and medium to large reduction of binge eating in both II-conditions compared to the control condition, that was sustained for 6 months. No additional effects of MI were found.

Conclusions

Applying IIs results in long-lasting reductions in subjective binge eating. The absence of additional effects of MI may be due to floor effects. Also, participants in the IIs without MI condition may have applied MI without being instructed to do so. In future research, ideally with a clinical sample, it is recommended to prevent or control for this.  相似文献   
99.
100.
Murine muscles lacking both mitochondrial (Mi-CK) and cytoplasmic (MM-CK) creatine kinase (CK-/-) show depressed mechanical performance in association with low muscle ATP and enhanced IMP content. The aims of the present study were to elucidate the possible role of low ATP and high IMP content in impairment of mechanical performance in CK-/- mice and to establish whether CK-/- muscles are able to sustain repeated series of high-intensity contractions. The dorsal flexors of CK-/- and control mice were subjected in situ to two series of 12 tetanic contractions using a custom-made mouse isometric dynamometer. The muscle content of high-energy phosphates was analysed by HPLC. ATP content declined from 20.6+/-1.9 to 15.5+/-2.4 micromol x g(-1) dry weight (d.w.); IMP content increased from 1.2+/-0.4 to 2.4+/-1.1 micromol x g(-1) d.w. during the first contraction series in CK-/- muscle. Despite these unfavourable changes, maximal torque developed during the first contraction of either series did not differ, indicating that the altered content of ATP and IMP does not play a decisive role in impaired mechanical performance in CK-/- mice. The relative decline in torque during the two series did not differ in CK-/- (-20.4+/-6.6 vs. -23.8+/-9.9%). In contrast, wild-type (WT) muscles showed a significantly more pronounced decline during the second series (-12.3+/-7.4 vs. -20.1+/-6.8%). Muscle ATP and IMP content did not change in CK-/-, whereas in WT IMP content increased significantly during the second contraction series. These findings indicate that CK-/- tolerate repeated series of high-intensity contractions better than WT, while in CK-/- muscle an additional source of energy is mobilised to regenerate ATP during the second series.  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