全文获取类型
收费全文 | 4277篇 |
免费 | 463篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 26篇 |
妇产科学 | 33篇 |
基础医学 | 334篇 |
口腔科学 | 9篇 |
临床医学 | 299篇 |
内科学 | 156篇 |
皮肤病学 | 21篇 |
神经病学 | 2968篇 |
特种医学 | 37篇 |
外科学 | 213篇 |
综合类 | 210篇 |
预防医学 | 81篇 |
眼科学 | 47篇 |
药学 | 284篇 |
2篇 | |
中国医学 | 13篇 |
肿瘤学 | 18篇 |
出版年
2024年 | 23篇 |
2023年 | 88篇 |
2022年 | 67篇 |
2021年 | 98篇 |
2020年 | 144篇 |
2019年 | 168篇 |
2018年 | 152篇 |
2017年 | 191篇 |
2016年 | 189篇 |
2015年 | 195篇 |
2014年 | 261篇 |
2013年 | 374篇 |
2012年 | 229篇 |
2011年 | 238篇 |
2010年 | 234篇 |
2009年 | 245篇 |
2008年 | 271篇 |
2007年 | 242篇 |
2006年 | 186篇 |
2005年 | 192篇 |
2004年 | 148篇 |
2003年 | 134篇 |
2002年 | 123篇 |
2001年 | 96篇 |
2000年 | 66篇 |
1999年 | 49篇 |
1998年 | 42篇 |
1997年 | 56篇 |
1996年 | 36篇 |
1995年 | 23篇 |
1994年 | 22篇 |
1993年 | 14篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 18篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 6篇 |
1985年 | 16篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有4768条查询结果,搜索用时 15 毫秒
1.
Mani N Pavuluri Megan Marlow O'Connor Erin M Harral Melissa Moss John A Sweeney 《Neuropsychopharmacology》2006,60(9):951-956
BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD. 相似文献
2.
Gerald T Voelbel Marsha E Bates Jennifer F Buckman Gahan Pandina Robert L Hendren 《Neuropsychopharmacology》2006,60(9):942-950
BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group. 相似文献
3.
The axon terminals of cone horizontal cells in the goldfish retina form typical chemical synaptic contacts in the middle of the inner nuclear layer. Approximately 60% of the identified postsynaptic elements were perikarya, axons and dendrites of bipolar cells. The other identified postsynaptic elements were perikarya and processes of interplexiform cells. We propose that the horizontal cell axon terminal contribute to the antagonistic surround responses of the bipolar cells and that they modulate inputs to the outer plexiform layer conveyed by interplexiform cells. Output synapses from horizontal cell axons to unidentified neuronal processes as well as occasional input synapses to the axons from interplexiform cell processes and unidentified perikarya were also observed in the same region of the inner nuclear layer. 相似文献
4.
Catherine M. Cahill Melissa J. Green Rajeev Jairam Gin S. Malhi 《Early intervention in psychiatry》2007,1(2):138-149
Aim: This article reviews research centred around juvenile bipolar disorder with particular reference to diagnostic difficulties. Putative deficits are scrutinized with respect to trait likelihood and the roles of neuropsychology and neuroimaging in enhancing our understanding of juvenile bipolar disorder are discussed. Methods: Search terms including childhood, adolescent, youth and juvenile combined with the terms ‘bipolar disorder’, mania, depression and hypomania were used to identify relevant studies in MEDLINE and PsychLit. Results: Over recent years research into this relatively new disorder has increased phenomenally. Key issues within the field include diagnostic specificity, the heritability of the disorder, the impact of comorbidity and the implications of neuropsychological and neuroimaging findings. Conclusion: Despite concerning controversies in literature the diagnosis of bipolar disorder in children and adolescents as compared with adults, promising future research directions include better neurological characterization of the disorder through the application of findings from clinical populations, neuropsychological and neuroimaging research. 相似文献
5.
Leo Sher Juan J Carballo Michael F Grunebaum Ainsley K Burke Gil Zalsman Yung-yu Huang J John Mann Maria A Oquendo 《Bipolar disorders》2006,8(5P2):543-550
Objectives: Bipolar disorder is a severe illness that is associated with suicidal behavior. A biological predictor of highly lethal suicide attempts in patients with bipolar disorder would be valuable. We hypothesized that cerebrospinal fluid (CSF) monoamine metabolite levels are related to lethality of suicide attempts in bipolar patients and examined the relation between CSF 5-hydroxyindolacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) levels and maximum lethality of suicide attempts at baseline and during a 2-year follow up.
Methods: Twenty-seven bipolar depressed patients participated in the study. Demographic and clinical parameters were examined and recorded. Lumbar punctures were performed and CSF 5-HIAA, HVA, and MHPG were assayed by high-performance liquid chromatography with electrochemical detection. Following discharge, patients were evaluated after 3 months, 1 year, and 2 years. Each follow-up interview included an in-depth assessment of suicidal behavior during the intervening time period.
Results: Six subjects made suicide attempts during the 2-year follow-up. Bipolar patients who attempted suicide during the follow-up period had higher aggression and hostility scale scores compared to bipolar subjects who did not make a suicide attempt during the follow-up period. CSF 5-HIAA, HVA, and MHPG levels were negatively correlated with the maximum lethality of suicide attempts during the 2-year follow-up period.
Conclusions: Our finding is the first observation that CSF monoamine metabolite levels may be predictors of lethality of suicide attempts in patients with bipolar disorder. Further studies are necessary to answer the question whether CSF monoamine metabolite levels are clinically useful biochemical predictors of highly lethal suicide attempts or completed suicides. 相似文献
Methods: Twenty-seven bipolar depressed patients participated in the study. Demographic and clinical parameters were examined and recorded. Lumbar punctures were performed and CSF 5-HIAA, HVA, and MHPG were assayed by high-performance liquid chromatography with electrochemical detection. Following discharge, patients were evaluated after 3 months, 1 year, and 2 years. Each follow-up interview included an in-depth assessment of suicidal behavior during the intervening time period.
Results: Six subjects made suicide attempts during the 2-year follow-up. Bipolar patients who attempted suicide during the follow-up period had higher aggression and hostility scale scores compared to bipolar subjects who did not make a suicide attempt during the follow-up period. CSF 5-HIAA, HVA, and MHPG levels were negatively correlated with the maximum lethality of suicide attempts during the 2-year follow-up period.
Conclusions: Our finding is the first observation that CSF monoamine metabolite levels may be predictors of lethality of suicide attempts in patients with bipolar disorder. Further studies are necessary to answer the question whether CSF monoamine metabolite levels are clinically useful biochemical predictors of highly lethal suicide attempts or completed suicides. 相似文献
6.
Tonsillectomy is an operation performed by various techniques. We have developed a bipolar diathermy dissection technique that allows a low intra-operative blood loss without an increase in complications. The average blood loss was less than 4 ml in 100 patients. Most were able to drink and eat by 4 and 10 hours respectively. There was no increase in analgesic requirements. No primary haemorrhage was recorded; three patients had a secondary haemorrhage. The technique allows accurate coagulation of blood vessel and is an easy procedure to learn. 相似文献
7.
Manic episode with psychotic symptoms induced by subthalamic nucleus stimulation in a patient with Parkinson's disease. 总被引:5,自引:0,他引:5
Jan Herzog Julia Reiff Paul Krack Karsten Witt Bettina Schrader Dieter Müller Günther Deuschl 《Movement disorders》2003,18(11):1382-1384
Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an established therapy for Parkinson's disease (PD). A manic episode with psychotic symptoms induced by STN-DBS occurred in a previously psychiatrically healthy patient, focusing on the role of STN-DBS in influencing not only motor but also emotional behaviour. 相似文献
8.
Objectives: The aims of this paper are to provide an overview of neuroimaging findings specific to bipolar disorder and suicide, and to consider rational approaches to the design of future in vivo studies in youth at risk.
Methods: Neuroimaging and related neurobiological literature pertaining to bipolar disorder and suicide in adult and pediatric samples was reviewed in a non-quantitative manner.
Results: Specific structural and functional brain findings in bipolar disorder are described, where possible in the context of relevant current neurobiological theories of etiology. Diagnostic and prognostic implications are discussed.
Conclusions: The simultaneous use of complementary neurobiological approaches may be a powerful way of identifying and validating factors reliably associated with bipolar disorder and suicide. A profile of neurobiological markers with which to screen for bipolar disorder and suicide risk may provide for earlier and more accurate diagnosis, perhaps even in the pre- or subsyndromal stages in high-risk youth. 相似文献
Methods: Neuroimaging and related neurobiological literature pertaining to bipolar disorder and suicide in adult and pediatric samples was reviewed in a non-quantitative manner.
Results: Specific structural and functional brain findings in bipolar disorder are described, where possible in the context of relevant current neurobiological theories of etiology. Diagnostic and prognostic implications are discussed.
Conclusions: The simultaneous use of complementary neurobiological approaches may be a powerful way of identifying and validating factors reliably associated with bipolar disorder and suicide. A profile of neurobiological markers with which to screen for bipolar disorder and suicide risk may provide for earlier and more accurate diagnosis, perhaps even in the pre- or subsyndromal stages in high-risk youth. 相似文献
9.
Michael F Grunebaum Hanga C Galfalvy C Matthew Nichols Nathilee A Caldeira Leo Sher Kanita Dervic Ainsley K Burke J John Mann Maria A Oquendo 《Bipolar disorders》2006,8(5P1):496-502
Objectives: The goal of this retrospective study was to examine factors differentiating persons with bipolar disorder who did or did not have comorbid lifetime substance use disorders (SUD) at an index assessment. We also explored the chronology of onset of mood and SUD.
Methods: We studied 146 subjects with DSM-defined bipolar disorder. Subgroups with and without lifetime SUD were compared on demographic and clinical measures.
Results: Substance abuse disorders in this bipolar sample were associated with male sex, impulsive-aggressive traits, comorbid conduct and Cluster B personality disorders, number of suicide attempts and earlier age at onset of a first mood episode. In a multivariable logistic regression analysis, male sex and aggression and possibly earlier age at mood disorder onset were associated with SUD. In those with or without SUD, the first mood episode tended to be depressive and to precede the onset of SUD.
Conclusions: In persons with bipolar disorder, an earlier age of onset and aggressive traits appear to be factors associated with later development of comorbid SUD. 相似文献
Methods: We studied 146 subjects with DSM-defined bipolar disorder. Subgroups with and without lifetime SUD were compared on demographic and clinical measures.
Results: Substance abuse disorders in this bipolar sample were associated with male sex, impulsive-aggressive traits, comorbid conduct and Cluster B personality disorders, number of suicide attempts and earlier age at onset of a first mood episode. In a multivariable logistic regression analysis, male sex and aggression and possibly earlier age at mood disorder onset were associated with SUD. In those with or without SUD, the first mood episode tended to be depressive and to precede the onset of SUD.
Conclusions: In persons with bipolar disorder, an earlier age of onset and aggressive traits appear to be factors associated with later development of comorbid SUD. 相似文献
10.
Bipolar affective disorder. II. EEG, neuropsychological, and clinical correlates of CT abnormality 总被引:1,自引:0,他引:1
M J Dewan C V Haldipur M F Boucher T Ramachandran L F Major 《Acta psychiatrica Scandinavica》1988,77(6):677-682
Since the clinical significance of CT abnormalities found in bipolar patients remains obscure, we studied 26 DSM-III bipolar patients who had specific CT abnormalities (third ventricle enlargement, and hyperdensity of the caudate, thalamus, anterior frontal white matter, and right temporal lobe) on numerous parameters such as EEG, the Halstead-Reitan Neuropsychological Battery, premorbid personality adjustment, family history of affective disorder, positive and negative symptoms, employment history, and response to lithium carbonate treatment. None of these measures could differentiate between the CT abnormal and CT normal subgroups. The implications of these findings are discussed. 相似文献