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   3545篇
  免费   203篇
  国内免费   8篇
耳鼻咽喉   27篇
儿科学   103篇
妇产科学   93篇
基础医学   405篇
口腔科学   49篇
临床医学   477篇
内科学   498篇
皮肤病学   72篇
神经病学   391篇
特种医学   89篇
外科学   409篇
综合类   24篇
一般理论   1篇
预防医学   575篇
眼科学   29篇
药学   203篇
中国医学   6篇
肿瘤学   305篇
  2024年   4篇
  2023年   36篇
  2022年   51篇
  2021年   111篇
  2020年   68篇
  2019年   91篇
  2018年   108篇
  2017年   85篇
  2016年   109篇
  2015年   89篇
  2014年   116篇
  2013年   200篇
  2012年   260篇
  2011年   312篇
  2010年   137篇
  2009年   130篇
  2008年   226篇
  2007年   266篇
  2006年   225篇
  2005年   244篇
  2004年   233篇
  2003年   226篇
  2002年   211篇
  2001年   34篇
  2000年   23篇
  1999年   14篇
  1998年   27篇
  1997年   22篇
  1996年   10篇
  1995年   7篇
  1994年   7篇
  1993年   13篇
  1992年   10篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   1篇
  1987年   3篇
  1986年   4篇
  1985年   6篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   3篇
  1979年   2篇
  1976年   1篇
  1973年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有3756条查询结果,搜索用时 31 毫秒
101.
Optimal management of rectal cancer depends on obtaining accurate and detailed staging information at the time of diagnosis. The majority of this comes from radiological staging investigations such as computed tomography (CT), magnetic resonance imaging (MRI) and endoanal ultrasound (EAUS). Whilst there is little debate on the use of CT to assess distant spread of disease, there is still variation in the use of MRI or EAUS in the local staging of rectal cancer. Both techniques have their roles but MRI is better able to visualise the entire rectum and mesorectum as well as accurately identify the circumferential resection (CRM) margin in relation to the tumour edge. Breach of the CRM is one of the most important predictors of local recurrence and knowledge of its relationship to the tumour determines initial management. MRI has additional advantages in being able to identify other poor prognostic factors such as extramural venous invasion (EMVI) and mucin deposition, which further influence oncological treatment. It also provides the surgeon with accurate information on the relationship of the tumour to surrounding structures and the sphincter complex which is important for surgical planning. This review highlights the important determinants of local staging in rectal cancer and presents the evidence to answer the question as to which is a better imaging modality—MRI or EAUS?  相似文献   
102.

Background

The purpose of this study was to describe a single-institution experience with adrenal metastasectomy and to elucidate factors that may bear prognostic significance.

Methods

This is a single-center, retrospective review of patients with adrenal metastasis who underwent adrenalectomy performed with curative intent between 2000 and 2012. The Kaplan–Meier method was used to evaluate overall survival from time of adrenalectomy to death or last follow-up. Primary endpoint was death from any cause. Clinical variables were examined for association with survival.

Results

The study included 62 patients with mean age of 60 (±12) years; 55 % (34 of 62) were male, 85 % (53 of 62) presented with isolated adrenal metastasis, and 82 % (51 of 62) had metachronous disease with median disease-free interval (DFI) of 22 months (range, 6–217 months). Non-small cell lung cancer (NSCLC) was the most common primary comprising 50 % of cases. Median survival for the study population was 30 months (range, 1–145 months) and 5-year survival was 31 %. Patients with NSCLC had significantly shortened survival compared with non-NSCLC with median and 5-year survival of 17 versus 47 months and 27 % versus 38 %, respectively (p = .033). Synchronous metastasis (p = .028) and DFI < 12 months (p = .038) were also associated with worse survival outcome, though male gender (p = .69) and oligometastatic disease (p = .62) were not.

Conclusions

Adrenal metastasectomy resulted in median survival of 30 months and 5-year survival of 31 %. Shorter survival was associated with lung primary, short disease-free interval, and synchronous metastasis, but not with the presence of oligometastatic disease provided that the primary cancer and additional metastatic lesions were adequately controlled and amenable to resection.  相似文献   
103.

Background

Preprocedure clinical and pathologic factors have failed to consistently differentiate complete response (CR) from progressive disease (PD) in patients after isolated limb infusion (ILI) with melphalan for unresectable in-transit extremity melanoma.

Methods

Multiplex immunobead assay technology (Milliplex MAP Human Cytokine/Chemokine Magnetic Bead Panel, Millipore Corp., Billerica, MA; and Magpix analytical test instrument, Luminex Corp., Austin, TX) was performed on pre-ILI plasma to determine concentrations of selected cytokines (MIP-1α, IL-1Rα, IP-10, IL-1β, IL-1α, MCP-1, IL-6, IL-17, EGF, IL-12p40, VEGF, GM-CSF, and MIP-1β) on a subset of patients (n = 180) who experienced CR (n = 23) or PD (n = 24) after ILI. Plasma from normal donors (n = 12) was also evaluated.

Results

Of 180 ILIs performed, 28 % (95 % confidence interval 22–35, n = 50) experienced a CR, 14 % (n = 25) experienced a partial response, 11 % (n = 21) had stable disease, 34 % (n = 61) had PD, and 13 % (n = 23) were not evaluable for response. Tumor characteristics and pharmacokinetics appeared similar between CR (n = 23) and PD (n = 24) patients who underwent cytokine analysis. Although there were no differences in cytokine levels between CR and PD patients, there were differences between the melanoma patients and controls. MIP-1α, IL-1Rα, IL-1β, IL-1α, IL-17, EGF, IL-12p40, VEGF, GM-CSF, and MIP-1β were significantly higher in normal controls compared to melanoma patients, while IP-10 was lower (p < 0.001) in controls compared to melanoma patients.

Conclusions

Patients with unresectable in-transit melanoma appear to have markedly decreased levels of immune activating cytokines compared to normal healthy controls. This further supports a potential role for immune-targeted therapies and immune monitoring in patients with regionally advanced melanoma.  相似文献   
104.
This paper highlights the results of a consensus meeting regarding best practices for the assessment and treatment of co-occurring traumatic brain injury (TBI) and mental health (MH) problems among Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn Veterans seeking care in non-Veterans Affairs Colorado community MH settings. Twenty individuals with expertise in TBI screening, assessment, and intervention, as well as the state MH system, convened to establish and review questions and assumptions regarding care for this Veteran population. Unanimous consensus regarding best practices was achieved. Recommendations for improving care for Veterans seeking care in community MH settings are provided.  相似文献   
105.
Early studies reported preserved formulaic language in left hemisphere damaged subjects and reduced incidence of formulaic expressions in the conversational speech of stroke patients with right hemispheric damage. Clinical observations suggest a possible role also of subcortical nuclei. This study examined formulaic language in the spontaneous speech of stroke patients with left, right, or subcortical damage. Four subjects were interviewed and their speech samples compared to normal speakers. Raters classified formulaic expressions as speech formulae, fillers, sentence stems, and proper nouns. Results demonstrated that brain damage affected novel and formulaic language competence differently, with a significantly smaller proportion of formulaic expressions in subjects with right or subcortical damage compared to left hemisphere damaged or healthy speakers. These findings converge with previous studies that support the proposal of a right hemisphere/subcortical circuit in the management of formulaic expressions, based on a dual‐process model of language incorporating novel and formulaic language use.  相似文献   
106.
Pharmacologic inactivation or genetic deletion of adenosine A2A receptors protects ischemic neurons in adult animals, but studies in neonatal hypoxia-ischemia (H-I) are inconclusive. The present study in neonatal piglets examined the hypothesis that A2A receptor signaling after reoxygenation from global H-I contributes to injury in highly vulnerable striatal neurons where A2A receptors are enriched. A2A receptor immunoreactivity was detected in striatopallidal neurons. In nonischemic piglets, direct infusion of the selective A2A receptor agonist CGS 21680 through microdialysis probes into putamen increased phosphorylation of N-methyl-D-aspartic acid (NMDA) receptor NR1 subunit and Na+,K+-ATPase selectively at protein kinase A (PKA)-sensitive sites. In ischemic piglets, posttreatment with SCH 58261, a selective A2A receptor antagonist, improved early neurologic recovery and preferentially protected striatopallidal neurons. SCH 58261 selectively inhibited the ischemia-induced phosphorylation of NR1, Na+,K+-ATPase, and cAMP-regulated phosphoprotein 32 KDa (DARPP32) at PKA-sensitive sites at 3 hours of recovery and improved Na+,K+-ATPase activity. SCH 58261 also suppressed ischemia-induced protein nitration and oxidation. Thus, A2A receptor activation during reoxygenation contributes to the loss of a subpopulation of neonatal putamen neurons after H-I. Its toxic signaling may be related to DARPP32-dependent phosphorylation of PKA-sensitive sites on NR1 and Na+,K+-ATPase, thereby augmenting excitotoxicity-induced oxidative stress after reoxygenation.  相似文献   
107.
JL, a 25-year-old physiotherapist, became densely amnesic following herpes simplex viral encephalitis (HSVE), causing bilateral damage to medial and ventral areas of her frontal and temporal lobes and their associated circuitry. Three years post-onset, her WAIS-R full scale IQ (Verbal 74, Performance 102) showed an estimated loss of ± 50 points. She displayed severe global amnesia and markedly impaired social cognition. However, her immediate memory, perceptual priming, and cognitive problem-solving abilities were relatively spared. Her retention of professional skills was assessed using simulated physiotherapy scenarios. JL was able to demonstrate some procedural skills spontaneously, but was unable to apply them precisely and flexibly to individual patient needs. She showed no memory of theoretical or propositional physiotherapy knowledge, and could neither plan treatment nor reason clinically. Her performance was well below that of four other physiotherapists who had also not practised for 4 years. Thus, despite the relative sparing of her implicit memory, JL's performance lacked the co-ordinated operation of declarative and implicit long-term memory and the links to working memory that are necessary for the flexible performance of complex professional procedures.  相似文献   
108.
There are indications that awareness may have an important impact on functioning and response to rehabilitative interventions in early-stage Alzheimer's disease (AD), yet studies have so far produced few clear findings, and a comprehensive explanatory model is needed together with a reliable assessment method. A theory-driven approach to assessing awareness in early-stage Alzheimer's disease was used to develop the Memory Awareness Rating Scale (MARS), a measure that addresses key methodological limitations of the assessment methods adopted in existing studies. The MARS was piloted with 12 couples where one partner had a diagnosis of AD. This demonstrated that the MARS has satisfactory psychometric properties, and suggested some refinements to the scale that may improve its usefulness. Results obtained with the MARS allow further consideration of theoretical and methodological issues that arise in attempting to understand and assess awareness. The development of this rigorous method of assessing awareness of memory difficulties in early-stage AD provides a basis for further investigation of the relationship between awareness of memory difficulties and outcome of neuropsychological rehabilitation in early-stage AD.  相似文献   
109.
110.
Valproic acid is commonly used in the treatment of both focal and generalized epilepsies and is often well tolerated. There are many reported cases of hyperammonemic encephalopathy and other well-known side effects reported during use of valproic acid either alone or in combination with other antiepileptics. This case report demonstrates valproic acid toxicity in the presence of lacosamide, which has not previously been reported. Full recovery occurred after withdrawal of both valproic acid and lacosamide.  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