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   4404篇
  免费   240篇
  国内免费   19篇
耳鼻咽喉   23篇
儿科学   139篇
妇产科学   99篇
基础医学   545篇
口腔科学   90篇
临床医学   420篇
内科学   809篇
皮肤病学   92篇
神经病学   424篇
特种医学   106篇
外科学   499篇
综合类   19篇
一般理论   4篇
预防医学   503篇
眼科学   125篇
药学   279篇
中国医学   4篇
肿瘤学   483篇
  2024年   3篇
  2023年   45篇
  2022年   95篇
  2021年   177篇
  2020年   121篇
  2019年   147篇
  2018年   158篇
  2017年   115篇
  2016年   130篇
  2015年   132篇
  2014年   178篇
  2013年   230篇
  2012年   361篇
  2011年   349篇
  2010年   217篇
  2009年   204篇
  2008年   260篇
  2007年   307篇
  2006年   287篇
  2005年   246篇
  2004年   216篇
  2003年   223篇
  2002年   155篇
  2001年   22篇
  2000年   18篇
  1999年   17篇
  1998年   43篇
  1997年   31篇
  1996年   19篇
  1995年   19篇
  1994年   18篇
  1993年   17篇
  1992年   5篇
  1991年   9篇
  1990年   9篇
  1989年   10篇
  1988年   6篇
  1987年   8篇
  1986年   5篇
  1985年   2篇
  1984年   4篇
  1983年   5篇
  1982年   14篇
  1981年   5篇
  1980年   3篇
  1978年   3篇
  1976年   2篇
  1974年   3篇
  1973年   2篇
  1962年   1篇
排序方式: 共有4663条查询结果,搜索用时 15 毫秒
81.
Objectives. We set out to assess the occurrence of new depression and anxiety diagnoses in women 3 years after they sought an abortion.Methods. We conducted semiannual telephone interviews of 956 women who sought abortions from 30 US facilities. Adjusted multivariable discrete-time logistic survival models examined whether the study group (women who obtained abortions just under a facility’s gestational age limit, who were denied abortions and carried to term, who were denied abortions and did not carry to term, and who received first-trimester abortions) predicted depression or anxiety onset during seven 6-month time intervals.Results. The 3-year cumulative probability of professionally diagnosed depression was 9% to 14%; for anxiety it was 10% to 15%, with no study group differences. Women in the first-trimester group and women denied abortions who did not give birth had greater odds of new self-diagnosed anxiety than did women who obtained abortions just under facility gestational limits.Conclusions. Among women seeking abortions near facility gestational limits, those who obtained abortions were at no greater mental health risk than were women who carried an unwanted pregnancy to term.There has been much interest in understanding the effects of abortion, one of the most commonly performed surgical procedures,1,2 on women’s mental health outcomes. Leading reviews on this topic have found no evidence of mental health harm from an abortion,3–6 with the exception of 1 review7 which has been critically refuted.5,8–11 These reviews have called for more research of women seeking abortion beyond the first trimester, longitudinal studies, studies that control for preexisting mental health conditions, and studies that compare women who have had an abortion to women who want an abortion but are unable to get one.3–5Most of the few longitudinal studies available have been conducted outside of the United States. A Danish population-based cohort study assessed the onset of a first psychiatric event before and up to 12 months after a first-trimester abortion and found no increased risk of mental disorders after abortion.12 A Norwegian study followed 120 women for 5 years and compared the psychological response of women who had first-trimester abortions to women who had miscarriages,13 finding no differences in depression or anxiety between the 2 groups.13 Fergusson et al. published a series of articles based on a longitudinal study conducted in New Zealand that suggested that abortion is associated with an increased risk of mental health problems.14,15 These studies, however, have a number of shortcomings that have been discussed elsewhere and may not be generalizable to the US setting.4 One of the few longitudinal US studies is a secondary analysis of the National Comorbidity Survey that compared the mental health outcomes of women who obtained abortions to women who gave birth.16 In this study, the predictive effect of abortion on mental health conditions disappeared when analyses controlled for mental health history.16In this article, we report on the first 3 years of a 5-year longitudinal study, the Turnaway Study, which was specifically designed to examine the psychological consequences of undergoing or being denied an abortion in the United States. Previous findings from the Turnaway Study have demonstrated that most women seeking abortions for financial-, timing-, or partner-related reasons17 commonly express feelings of relief after the abortion and feel that abortion was the right decision.18 The mental health symptom trajectories of women who sought an abortion differed little from those who were denied one; however, both improved over time.19 Our previous analysis19 assessed self-reported mental health symptoms at 5 discrete points in time over 2 years (potentially missing symptoms of anxiety and depression that may have occurred in between interview dates or after 2 years), and it did not assess women’s severity of symptoms or other circumstances that may have led to a clinical diagnosis of depression or anxiety. This study further contributes to the literature by assessing diagnoses of new depression and anxiety disorders that may have occurred in women at any point up to 3 years after having sought an abortion.  相似文献   
82.
83.
Objective: The aim of the CAMPO-RHE study was to determine the incidence of rheumatoid arthritis (RA), psoriatic arthritis (PsA) and polymyalgia rheumatica (PMR) in patients attending a rheumatologic outpatient’s clinic of a new institution in Campobasso, Italy.

Methods: Campobasso is a small town of approximately 50,000 inhabitants located in the inland territory of central Italy (Molise), and Public Health is managed from a single health authority. In Italy, all citizens are registered with a National Health System of General Practitioner (GP) Physicians. Between the 1st of June 2014 and the 31st of May 2016, all consecutive adult patients, sent by a GP, of Campobasso with any diagnosis of musculoskeletal symptoms/signs/complaints were evaluated in a single rheumatology outpatient clinic of our Academic Unit. The clinic represents the first and unique reference for GPs about rheumatic diseases in the territory. Subjects were classified using the 2010 EULAR criteria for RA, the CASPAR criteria for PsA and the 2012 ACR classification criteria for PMR.

Results: 1003 adult patients, sent by GPs, with articular or musculoskeletal complaints visited our clinic. Of these, 409 inhabitants of the municipality of Campobasso were evaluated for the study. During the 2-year study period we diagnosed 18, 19 and 12 new cases of RA, PsA and PMR respectively, with a new incident cases rate of 21.4, 22.59 and 27.43/100,000/year on the population at risk.

Conclusion: The results of our study could contribute to better define the incidence of these rheumatic diseases classified with the new classification criteria.  相似文献   

84.
Anxiety sensitivity (AS), a fear of arousal-related sensations, is prevalent in a number of disorders. We examined the relationship between internalizing symptoms and the anxiety sensitivity components of physical, social, and cognitive concerns in a sample of 165 patients seeking treatment in a clinic specializing in cognitive behavioral therapy for anxiety-related disorders. Social anxiety symptoms were associated with greater social concerns. Cognitive concerns were characteristic of both depression and generalized anxiety symptoms, suggesting these two classes of symptoms may share AS symptomatology. Physical concerns were specifically related to panic symptoms. Although obsessive–compulsive symptoms were related to cognitive concerns using univariate regression, these symptoms were not strongly related to any of the anxiety sensitivity components when the correlation between disorders was taken into account. Thus, within the internalizing symptoms studied here, the anxiety sensitivity domains were most relevant to panic, social anxiety, generalized anxiety, and depressive symptoms and less related to obsessive–compulsive symptoms.  相似文献   
85.
Control of cardiomyocyte cytosolic Ca2+ levels is crucial in determining inotropic status and ischemia/reperfusion stress response. Responsive to fluctuations in cellular Ca2+, Ca2+/calmodulin‐dependent protein kinase II (CaMKII) is a serine/threonine kinase integral to the processes regulating cardiomyocyte Ca2+ channels/transporters. CaMKII is primarily expressed either in the δB or δC splice variant forms, which may mediate differential influences on cardiomyocyte function and pathological response mechanisms. Increases in myocyte Ca2+ levels promote the binding of a Ca2+/calmodulin complex to CaMKII, to activate the kinase. Activity is also maintained through a series of post‐translational modifications within a critical region of the regulatory domain of the protein. Recent data indicate that the post‐translational modification status of CaMKIIδB/δC variants may have an important influence on reperfusion outcomes. This study provided the first evidence that the specific type of CaMKII post‐translational modification has a role in determining target selectivity of downstream Ca2+ transporters. The study was also able to demonstrate that the phosphorylated form of CaMKII closely co‐localizes with CaMKIIδB in the nuclear/myofilament fraction, contrasting with a co‐enrichment of oxidized CaMKII in the membrane fraction with CaMKIIδC. It has also been possible to conclude that a hyper‐phosphorylation of CaMKII (Thr287) in reperfused hearts represents a hyper‐activation of the CaMKIIδB, which exerts anti‐arrhythmic actions through an enhanced capacity to selectively increase sarcoplasmic reticulum Ca2+ uptake and maintain cytosolic Ca2+ levels. This suggests that suppression of global CaMKIIδ may not be an efficacious approach to developing optimal pharmacological interventions for the vulnerable heart.  相似文献   
86.
Clinical Rheumatology - We aimed to evaluate the (a) potential predictors of first biological disease-modifying anti-rheumatic drug (bDMARD) failure and (b) factors associated with failure of...  相似文献   
87.
Clinical Rheumatology - Calcinosis is dystrophic calcification of the soft tissue which can lead to painful and debilitating disease. It is commonly seen in patients with systemic sclerosis (SSc)....  相似文献   
88.
When several Helicobacter pylori eradication treatments fail, guidelines recommend a cultured guided approach; however, culture is not widely available. Therefore, a rifabutin based regimen could be the best solution. Rifabutin indeed shows a low rate of antibiotic resistance. Rifabutin is generally used in combination with amoxicillin in a triple therapy, with eradication rates about 80% in third-line regimens. The ideal duration of this therapy should range between 10 and 12 d. Combinations with antibiotics other than amoxicillin have demonstrated even better results, such as vonoprazan, which is a type of novel acid suppressor drug. Finally, a new formulation of triple therapy in a single capsule is under investigation, which is a field that deserves further investigation. Some notes of caution about rifabutin should be mentioned. This drug is used to treat tuberculosis or atypical mycobacteria; therefore, before starting a rifabutin-based eradication regimen, Mycobacterium tuberculosis infection should be thoroughly tested, since its use could promote the development of antibiotic resistance, thus affecting its effectiveness against Koch’s bacillus. Additionally, some serious side effects must be evaluated before starting any rifabutin-based therapy. Adverse effects include fever, nausea, vomiting and bone marrow suppression. For this reason, full blood count surveillance is required.  相似文献   
89.
Fifty-five patients with Graves' disease (GD) and mild to moderate Graves' ophthalmopathy (GO) underwent near-total thyroidectomy (Tx). In 16 patients this was followed by a standard ablative dose of (131)I because of the hystologic evidence of differentiated thyroid carcinoma. We retrospectively evaluated whether or not GO activity could be affected by thyroid surgery alone or followed by complete ablation of thyroid tissue. Accordingly, on the basis of clinical activity score (CAS) values prior to thyroidectomy, we identified two groups: group A with active GO (CAS > or = 3; n = 31) and group B with inactive GO (CAS < or = 2; n = 24). CAS values were then recorded at 6, 12, and 24 months after surgery/(131)I ablation. Over the course of the follow-up period, GO became inactive in approximately 70% of group A patients (CAS 4.2 +/- 0.8 at baseline, 2.1 +/- 2.0 at 24 months, p < 0.0001) and became active in 37.5% patients from group B. When we examined GO activity according to the type of treatment used (Tx or Tx and (131)I), the prevalence of inactive GO both short- and long-term, was significantly higher in the group of patients who underwent Tx and (131)I ablation. Therefore, this seems to be a more effective means of inducing and maintaining inactive GO.  相似文献   
90.
Endothelin has been identified as a potent vasoconstrictor. The aim of this study was to evaluate urinary endothelins and their relation to other markers of renal damage, such as microalbuminuria, creatinine, and N-acetyl-beta-glucosaminidase (NAG), in a group of recently diagnosed (less than 1 year) hypertensive subjects and a control group. We selected 50 subjects and divided them into two groups: 27 hypertensive patients (15 females and 12 males) without previous pharmacologic therapy, and 23 healthy, normotensive subjects (12 females and 11 males). All patients underwent a history and physical examination, chest x-ray, electrocardiography, funduscopy, and hematologic and biochemical analyses. Endothelins, microalbuminuria, creatinine, and NAG values were also determined in 24-hour urine samples. Creatinine, microalbuminuria, and NAG values were found to be higher in hypertensive than in normotensive subjects. The hypertensive group showed a nonsignificant elevation of total endothelin. In conclusion, the determination of elevated urinary endothelin does not appear to be an early marker of organ damage in hypertensive subjects. The urinary excretion of protein, creatinine, and NAG was higher in hypertensive subjects. A positive correlation was found between the urinary excretion of endothelins and markers of renal damage, microalbuminuria and NAG values. The relationship between endothelins and hypertension was without statistical significance.  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