全文获取类型
收费全文 | 1046篇 |
免费 | 40篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 14篇 |
妇产科学 | 10篇 |
基础医学 | 126篇 |
口腔科学 | 36篇 |
临床医学 | 113篇 |
内科学 | 182篇 |
皮肤病学 | 10篇 |
神经病学 | 123篇 |
特种医学 | 118篇 |
外科学 | 147篇 |
综合类 | 5篇 |
预防医学 | 77篇 |
眼科学 | 53篇 |
药学 | 32篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 9篇 |
2021年 | 33篇 |
2020年 | 20篇 |
2019年 | 30篇 |
2018年 | 40篇 |
2017年 | 21篇 |
2016年 | 17篇 |
2015年 | 26篇 |
2014年 | 37篇 |
2013年 | 29篇 |
2012年 | 73篇 |
2011年 | 79篇 |
2010年 | 50篇 |
2009年 | 31篇 |
2008年 | 55篇 |
2007年 | 62篇 |
2006年 | 52篇 |
2005年 | 48篇 |
2004年 | 40篇 |
2003年 | 63篇 |
2002年 | 29篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 17篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 6篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1942年 | 3篇 |
排序方式: 共有1093条查询结果,搜索用时 15 毫秒
21.
Zeshan Ahmed Eileen H. Bigio Herbert Budka Dennis W. Dickson Isidro Ferrer Bernardino Ghetti Giorgio Giaccone Kimmo J. Hatanpaa Janice L. Holton Keith A. Josephs James Powers Salvatore Spina Hitoshi Takahashi Charles L. White III Tamas Revesz Gabor G. Kovacs 《Acta neuropathologica》2013,126(4):537-544
Recent studies have highlighted a group of 4-repeat (4R) tauopathies that are characterised neuropathologically by widespread, globular glial inclusions (GGIs). Tau immunohistochemistry reveals 4R immunoreactive globular oligodendroglial and astrocytic inclusions and the latter are predominantly negative for Gallyas silver staining. These cases are associated with a range of clinical presentations, which correlate with the severity and distribution of underlying tau pathology and neurodegeneration. Their heterogeneous clinicopathological features combined with their rarity and under-recognition have led to cases characterised by GGIs being described in the literature using various and redundant terminologies. In this report, a group of neuropathologists form a consensus on the terminology and classification of cases with GGIs. After studying microscopic images from previously reported cases with suspected GGIs (n = 22), this panel of neuropathologists with extensive experience in the diagnosis of neurodegenerative diseases and a documented record of previous experience with at least one case with GGIs, agreed that (1) GGIs were present in all the cases reviewed; (2) the morphology of globular astrocytic inclusions was different to tufted astrocytes and finally that (3) the cases represented a number of different neuropathological subtypes. They also agreed that the different morphological subtypes are likely to be part of a spectrum of a distinct disease entity, for which they recommend that the overarching term globular glial tauopathy (GGT) should be used. Type I cases typically present with frontotemporal dementia, which correlates with the fronto-temporal distribution of pathology. Type II cases are characterised by pyramidal features reflecting motor cortex involvement and corticospinal tract degeneration. Type III cases can present with a combination of frontotemporal dementia and motor neuron disease with fronto-temporal cortex, motor cortex and corticospinal tract being severely affected. Extrapyramidal features can be present in Type II and III cases and significant degeneration of the white matter is a feature of all GGT subtypes. Improved detection and classification will be necessary for the establishment of neuropathological and clinical diagnostic research criteria in the future. 相似文献
22.
Sofia Grade Liliana Bernardino João O. Malva 《International journal of developmental neuroscience》2013
Mobilization of remyelinating cells spontaneously occurs in the adult brain. These cellular resources are specially active after demyelinating episodes in early phases of multiple sclerosis (MS). Indeed, oligodendrocyte precursor cells (OPCs) actively proliferate, migrate to and repopulate the lesioned areas. Ultimately, efficient remyelination is accomplished when new oligodendrocytes reinvest nude neuronal axons, restoring the normal properties of impulse conduction. As the disease progresses this fundamental process fails. Multiple causes seem to contribute to such transient decline, including the failure of OPCs to differentiate and enwrap the vulnerable neuronal axons. Regenerative medicine for MS has been mainly centered on the recruitment of endogenous self-repair mechanisms, or on transplantation approaches. The latter commonly involves grafting of neural precursor cells (NPCs) or neural stem cells (NSCs), with myelinogenic potential, in the injured areas. Both strategies require further understanding of the biology of oligodendrocyte differentiation and remyelination. Indeed, the success of transplantation largely depends on the pre-commitment of transplanted NPCs or NSCs into oligodendroglial cell type, while the endogenous differentiation of OPCs needs to be boosted in chronic stages of the disease. Thus, much effort has been focused on finding molecular targets that drive oligodendrocytes commitment and development. The present review explores several aspects of remyelination that must be considered in the design of a cell-based therapy for MS, and explores more deeply the challenge of fostering oligodendrogenesis. In this regard, we discuss herein a tool developed in our research group useful to search novel oligodendrogenic factors and to study oligodendrocyte differentiation in a time- and cost-saving manner. 相似文献
23.
Obesity,Body Fat Distribution,and Physical Activity in School-age Children: an Urban and Rural Comparison in Valparaíso,Chile 总被引:1,自引:0,他引:1
Pablo A Lizana Paula Cisternas-Vallejos Leonel Araya Francisco Aguilera Manuel Mora 《Biomedical and environmental sciences : BES》2016,29(11):834-839
正This study analyze the relation between body composition,physical activity(PA),and sex in Chilean children from rural and urban public educational institutions.The prevalence of obesity(according to BMI)was 30.88%in urban children and 28.93%in rural children.Central obesity presented mainly in the rural girls.Approximately 相似文献
24.
Foroughi S Foster B Kim N Bernardino LB Scott LM Hamilton RG Metcalfe DD Mannon PJ Prussin C 《The Journal of allergy and clinical immunology》2007,120(3):594-601
BACKGROUND: Eosinophil-associated gastrointestinal disorders (EGIDs) are commonly associated with atopy and are being recognized with increasing frequency. Current therapy for EGIDs is inadequate. OBJECTIVE: We sought to determine the efficacy of anti-IgE therapy in EGIDs and investigate the role of IgE in disease pathogenesis. METHODS: Nine subjects with EGIDs received omalizumab every 2 weeks for 16 weeks while other therapy was held constant. Blood absolute eosinophil counts, tissue eosinophil counts, symptom scores, and free IgE levels were serially measured. Allergen skin testing and flow cytometry for basophil activation and FcepsilonRI were determined at baseline and at week 16. RESULTS: Omalizumab was associated with a decrease in absolute eosinophil count at both the week 16 (34%, P = .004) and combined weeks 12 to 16 (42%, P = .012) time points. Tissue eosinophils decreased in the duodenum (59%) and gastric antrum (69%) but did not reach statistical significance (P = .074 and .098, respectively). Esophageal eosinophil counts remained unchanged. Basophil and dendritic cell FcepsilonRI expression and free IgE levels were all significantly decreased (P < .005). Omalizumab increased the concentration of allergen required to trigger half-maximal basophil activation by 170-fold. Allergen skin test wheal and erythema responses decreased by 78% and 82%, respectively. Symptom scores were decreased at both the midstudy (63%) and end of study (70%) time points (P < .005 for both). CONCLUSION: These results demonstrate that IgE-mediated processes contribute to the generation of eosinophilic inflammation in EGIDs and suggest that anti-IgE therapy might be effective in these disorders. CLINICAL IMPLICATIONS: Anti-IgE might be a potential therapy for EGIDs. 相似文献
25.
van den Burg EH Engelmann J Bacelo J Gómez L Grant K 《Journal of neurophysiology》2007,97(3):2373-2384
Anesthetics may induce specific changes that alter the balance of activity within neural networks. Here we describe the effects of the GABA(A) receptor potentiating anesthetic etomidate on sensory processing, studied in a cerebellum-like structure, the electrosensory lateral line lobe (ELL) of mormyrid fish, in vitro. Previous studies have shown that the ELL integrates sensory input and removes predictable features by comparing reafferent sensory signals with a descending electromotor command-driven corollary signal that arrives in part through parallel fiber synapses with the apical dendrites of GABAergic interneurons. These synapses show spike timing-dependent depression when presynaptic activation is associated with postsynaptic backpropagating dendritic action potentials. Under etomidate, almost all neurons become tonically hyperpolarized. The threshold for action potential initiation increased for both synaptic activation and direct intracellular depolarization. Synaptically evoked inhibitory postsynaptic potentials (IPSPs) were also strongly potentiated and prolonged. Current source density analysis showed that backpropagation of action potentials through the apical dendritic arborization in the molecular layer was reduced but could be restored by increasing stimulus strength. These effects of etomidate were blocked by bicuculline or picrotoxin. It is concluded that etomidate affects both tonic and phasic inhibitory conductances at GABA(A) receptors and that increased shunting inhibition at the level of the proximal dendrites also contributes to increasing the threshold for action potential backpropagation. When stimulus strength is sufficient to evoke backpropagation, repetitive association of synaptic excitation with postsynaptic action potential initiation still results in synaptic depression, showing that etomidate does not interfere with the molecular mechanism underlying plastic modulation. 相似文献
26.
Eric M Gershon Leonel Rodriguez Ricardo A Arbizu 《World Journal of Clinical Pediatrics》2023,12(3):68-76
Hirschsprung’s disease (HSCR) is a congenital disorder characterized by failure of the neural crest cells to migrate and populate the distal bowel during gestation affecting different lengths of intestine leading to a distal functional obstruction. Surgical treatment is needed to correct HSCR once the diagnosis is confirmed by demonstrating the absence of ganglion cells or aganglionosis of the affected bowel segment. Hirschsprung’s disease associated enterocolitis (HAEC) is an inflammatory complication associated with HSCR that can present either in the pre- or postoperative period and associated with increased morbidity and mortality. The pathogenesis of HAEC remains poorly understood, but intestinal dysmotility, dysbiosis and impaired mucosal defense and intestinal barrier function appear to play a significant role. There is no clear definition for HAEC, but the diagnosis is primarily clinical, and treatment is guided based on severity. Here, we aim to provide a comprehensive review of the clinical presentation, etiology, pathophysiology, and current therapeutic options for HAEC. 相似文献
27.
Joo Augusto Franco Leonel Geovanna Vioti Maria Luana Alves Julia Cristina Benassi Diogo Tiago da Silva Julio Cesar Pereira Spada Vera Letticie de Azevedo Ruiz Wilma Aparecida Starke-Buzetti Rodrigo Martins Soares Trícia Maria Ferreira de Sousa Oliveira 《Transboundary and Emerging Diseases》2020,67(5):2013-2019
An epidemiological Leishmania spp. and entomological Phlebotomine sandflies survey was performed in cat shelters at leishmaniasis endemic area of Brazil. Blood and conjunctival swab (CS) samples were collected from 94 cats in two animal protection shelters. These samples were subjected to serological tests using the indirect immunofluorescence antibody test (IFAT) and indirect enzyme‐linked immunosorbent assay (ELISA) and to molecular test by polymerase chain reaction (PCR). In addition, a Phlebotomine sandflies survey was performed in the same shelters. The analyses revealed a positivity of 31.91% (30/94) through ELISA and 29.79% (28/94) through IFAT. The two serological tests showed a positive association with perfect agreement (k = 0.925). None of the cats were positive by Leishmania spp. DNA. One Lutzomyia (Lutzomyia) longipalpis male was found in one of the cat shelters. The results and the implications of our findings are discussed below. 相似文献
28.
Giovanni Liguori Nicola Pavan Gianluca d'Aloia Stefano Bucci Bernardino de Concilio Giorgio Mazzon Giangiacomo Ollandini Carlo Trombetta 《Asian journal of andrology》2014,16(4):650-651
Dear Editor, Testicular trauma is a frequent acquired cause o fin fertility; being accidents, work injuries and sport activities that are the most common causes of testicular traumas.1'2 Strangely, the issue of management of serious testicular trauma and fertility preservation has not been studied extensively before, existing only sporadic reports in international literature. Besides, no guidelines exist on fertility preservation in cases of important scrotal trauma when injury may result in irreparable damage to all testicular tissue (torsion of a solitary testis, bilateral synchronous testicular torsion, 相似文献
29.
Jorge Canena João Coimbra Diana Carvalho Catarina Rodrigues Mário Silva Mariana Costa David Horta António Mateus Dias Isabel Seves Gonçalo Ramos Leonel Ricardo António Pereira Coutinho Carlos Romão Pedro Mota Veiga 《Digestive diseases and sciences》2014,59(11):2779-2789
Background
Self-expandable metal stents (SEMSs) can be used for palliation of combined malignant biliary and duodenal obstructions. However, the results of the concomitant stent placement for the duration of the patients’ lives, as well as the need for and efficacy of endoscopic revision, are unclear.Aim
This study evaluated the clinical effectiveness of SEMS placement for combined biliary and duodenal obstructions throughout the patients’ lives and the need for endoscopic revision.Methods
This study is a retrospective multicenter study of 50 consecutive patients who underwent simultaneous or sequential SEMS placement for malignant biliary and duodenal obstructions. The data were collected to analyze the sustained relief of obstructive symptoms until the patients’ death and the efficacy of endoscopic revision, as well as stent patency, adverse events, survival and prognostic factors for stent patency.Results
Technical and immediate clinical success was achieved in all of the patients. Duodenal stricture occurred before the papilla in 35 patients (70 %), involved the papilla in 11 patients (22 %) and was observed distal to the papilla in four patients (8 %). Initial biliary stenting was performed endoscopically in 42 patients (84 %) and percutaneously in eight patients. After combined stenting, 30 patients (60 %) required no additional intervention until the time of their death. The remaining 20 patients were successfully treated using endoscopic stent reinsertion: nine patients needed biliary revision, three patients needed duodenal restenting and eight patients needed both biliary and duodenal reinsertion. The median duodenal stent patency and median biliary stent patency were 34 and 27 weeks, respectively. The median survival after combined stent placement was 18 weeks. A Cox multivariate analysis showed that duodenal stent obstruction after combined stenting was a risk factor for biliary stent obstruction (hazard ratio 6.85; 95 % confidence interval 1.43–198.98; P = 0.025).Conclusions
Endoscopic bilio-duodenal bypass is clinically effective, and the majority of the patients need no additional intervention until their death. Endoscopic revision is feasible and has a high success rate. 相似文献30.
Leonel Pereira Nicolina Dias Cledir SantosNelson Lima 《Enfermedades infecciosas y microbiología clínica》2014