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   463篇
  免费   34篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   41篇
妇产科学   7篇
基础医学   42篇
口腔科学   13篇
临床医学   66篇
内科学   100篇
皮肤病学   3篇
神经病学   58篇
特种医学   6篇
外科学   26篇
预防医学   51篇
眼科学   15篇
药学   32篇
肿瘤学   33篇
  2024年   1篇
  2023年   3篇
  2022年   6篇
  2021年   17篇
  2020年   13篇
  2019年   12篇
  2018年   16篇
  2017年   11篇
  2016年   19篇
  2015年   14篇
  2014年   19篇
  2013年   28篇
  2012年   46篇
  2011年   41篇
  2010年   21篇
  2009年   14篇
  2008年   29篇
  2007年   39篇
  2006年   31篇
  2005年   22篇
  2004年   32篇
  2003年   19篇
  2002年   10篇
  2001年   6篇
  2000年   2篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1994年   3篇
  1993年   2篇
  1991年   3篇
  1989年   1篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1982年   3篇
  1981年   1篇
  1977年   1篇
排序方式: 共有500条查询结果,搜索用时 15 毫秒
71.
OBJECTIVE: To describe the extent to which the voluntary movements of hemiparetic stroke patients are restricted to the hemiplegic limb synergies (which are marked by the inability to master individual joint movements) described by Brunnstr?m. The study also aimed to describe the extent to which the synergies are related to functioning. DESIGN: In a prospective observational study design, 64 consecutive hemiparetic stroke patients were assessed with Brunnstr?m's hemiplegic limb synergies, the modified Ashworth scale for spasticity, the Rivermead mobility index, and the Barthel ADL index. RESULTS: Three months after stroke, 8 of the 64 patients were moving completely or partly within the synergies. All patients whose movements were restricted to the synergies also exhibited spasticity. Hemiparetic patients whose movements were restricted to the synergies had significantly worse functioning scores than hemiparetic patients whose movements were not restricted to the synergies although severe disabilities were seen in both groups. CONCLUSIONS: Three months after stroke, the voluntary movements of only 13% of hemiparetic stroke patients were restricted to the synergies. The synergies were associated with spasticity and activity limitations. The use of the synergies might only be suitable for a small fraction of hemiparetic patients-namely, those displaying spasticity.  相似文献   
72.
Bacteriophages vB_YpeM_fEV-1 (fEV-1) and vB_YpeM_fD1 (fD1) were isolated from incoming sewage water samples in Turku, Finland, using Yersinia pestis strains EV76 and KIM D27 as enrichment hosts, respectively. Genomic analysis and transmission electron microscopy established that fEV-1 is a novel type of dwarf myovirus, while fD1 is a T4-like myovirus. The genome sizes are 38 and 167 kb, respectively. To date, the morphology and genome sequences of some dwarf myoviruses have been described; however, a proteome characterization such as the one presented here, has currently been lacking for this group of viruses. Notably, fEV-1 is the first dwarf myovirus described for Y. pestis. The host range of fEV-1 was restricted strictly to Y. pestis strains, while that of fD1 also included other members of Enterobacterales such as Escherichia coli and Yersinia pseudotuberculosis. In this study, we present the life cycles, genomes, and proteomes of two Yersinia myoviruses, fEV-1 and fD1.  相似文献   
73.
74.
75.
Alzheimer's disease (AD) is the major cause of dementia. During the development of AD, neurofibrillary tangles progress in a fixed pattern, starting in the transentorhinal cortex followed by the hippocampus and cortical areas. In contrast, the deposition of β-amyloid (Aβ) plaques, which are the other histological hallmark of AD, does not follow the same strict spatiotemporal pattern, and it correlates poorly with cognitive decline. Instead, soluble Aβ oligomers have received increasing attention as probable inducers of pathogenesis. In this study, we use microinjections into electrophysiologically defined primary hippocampal rat neurons to demonstrate the direct neuron-to-neuron transfer of soluble oligomeric Aβ. Additional studies conducted in a human donor-acceptor cell model show that this Aβ transfer depends on direct cellular connections. As the transferred oligomers accumulate, acceptor cells gradually show beading of tubulin, a sign of neurite damage, and gradual endosomal leakage, a sign of cytotoxicity. These observations support that intracellular Aβ oligomers play a role in neurodegeneration, and they explain the manner in which Aβ can drive disease progression, even if the extracellular plaque load is poorly correlated with the degree of cognitive decline. Understanding this phenomenon sheds light on the pathophysiological mechanism of AD progression. Additional elucidation will help uncover the detailed mechanisms responsible for the manner in which AD progresses via anatomical connections and will facilitate the development of new strategies for stopping the progression of this incapacitating disease.  相似文献   
76.

Abstract  

The theoretical framework is that muscle tension in the neck is related to insufficient muscular rest and is a risk factor for chronic pain and reduced work ability. Promoting muscle strength and muscle rest may increase work ability and reduce neck pain.  相似文献   
77.
Neuronal calcium (Ca2+)-binding proteins 1 and 2 (NECAB1/2) are members of the phylogenetically conserved EF-hand Ca2+-binding protein superfamily. To date, NECABs have been explored only to a limited extent and, so far, not at all at the spinal level. Here, we describe the distribution, phenotype, and nerve injury-induced regulation of NECAB1/NECAB2 in mouse dorsal root ganglia (DRGs) and spinal cord. In DRGs, NECAB1/2 are expressed in around 70% of mainly small- and medium-sized neurons. Many colocalize with calcitonin gene-related peptide and isolectin B4, and thus represent nociceptors. NECAB1/2 neurons are much more abundant in DRGs than the Ca2+-binding proteins (parvalbumin, calbindin, calretinin, and secretagogin) studied to date. In the spinal cord, the NECAB1/2 distribution is mainly complementary. NECAB1 labels interneurons and a plexus of processes in superficial layers of the dorsal horn, commissural neurons in the intermediate area, and motor neurons in the ventral horn. Using CLARITY, a novel, bilaterally connected neuronal system with dendrites that embrace the dorsal columns like palisades is observed. NECAB2 is present in cell bodies and presynaptic boutons across the spinal cord. In the dorsal horn, most NECAB1/2 neurons are glutamatergic. Both NECAB1/2 are transported into dorsal roots and peripheral nerves. Peripheral nerve injury reduces NECAB2, but not NECAB1, expression in DRG neurons. Our study identifies NECAB1/2 as abundant Ca2+-binding proteins in pain-related DRG neurons and a variety of spinal systems, providing molecular markers for known and unknown neuron populations of mechanosensory and pain circuits in the spinal cord.Calcium (Ca2+) plays a crucial role in many and diverse cellular processes, including neurotransmission (1). Glutamate and neuropeptides are neurotransmitters released from the central terminals of dorsal root ganglion (DRG) neurons in the spinal dorsal horn, where signals for different sensory modalities, including pain, are conveyed to higher centers (212). Neurotransmitter release is tightly regulated by Ca2+-dependent SNARE proteins whose activity is regulated by Ca2+-binding proteins (CaBPs) (1, 7, 13).Parvalbumin (PV), calbindin D-28K (CB), calretinin (CR), and secretagogin (Scgn) are extensively studied EF-hand CaBPs, and they have also emerged as valuable anatomical markers for morphologically and functionally distinct neuronal subpopulations (1417). The expression of CaBPs in DRG neurons has been thoroughly studied (18). Moreover, neuronal Ca2+ sensor 1 and downstream regulatory element-antagonist modulator (DREAM) are also EF-hand Ca2+-binding proteins in DRGs and the spinal cord (19, 20). Despite these advances, a CaBP has so far not been characterized in the majority of small- and medium-sized DRG neurons, many of which represent nociceptors.The subfamily of neuronal Ca2+-binding proteins (NECABs) consists of three members (NECAB1–NECAB3), probably as a result of gene duplication (21). NECABs are also EF-hand proteins, with one pair of EF-hand motifs in the N terminus and a putative antibiotic biosynthesis monooxygenase domain in the C terminus, which are linked by a NECAB homogeneous region (22). NECAB1/2 are restricted to the nervous system, whereas NECAB3 is also expressed in the heart and skeletal muscle (21).NECAB1 was first identified as the target protein of synaptotagmin I C2A-domain by affinity chromatography, with its expression restricted to layer 4 cortical pyramidal neurons, inhibitory interneurons, and hippocampal CA2 pyramidal cells in mouse brain (21, 23). The gene of the second member was cloned from mouse and initially named Necab. It encodes a 389-aa (NECAB2) (24). NECAB2 was identified as a downstream target of Pax6 in mouse retina, which is involved in retinal development (24, 25), as well as being a binding partner for the adenosine A2A receptor (22). Furthermore, an interaction between NECAB2 and metabotropic glutamate receptor 5 (mGluR5) was demonstrated in rat hippocampal pyramidal cells, possibly regulating mGluR5’s coupling to its signaling machinery (26). Finally, NECAB3, also known as XB51, was isolated as an interacting target for the neuron-specific X11-like protein and is possibly involved in the pathogenesis of Alzheimer’s disease (27, 28).Very recently, NECAB1/2 were shown to have complementary expression patterns in mouse hippocampus at the mRNA and protein levels, whereas NECAB3 is broadly distributed in the hippocampus (29). NECAB1-expressing cells were seen throughout the cell-sparse layers of Ammon’s horn and the hilus of the dentate gyrus. In contrast, NECAB2 is enriched in pyramidal cells of the CA2 region. A minority of NECAB1+ neurons were GABAergic yet did not coexpress PV, CB, or CR (29).Here, we investigated the expression of NECAB1/2 in mouse DRGs and spinal cord using quantitative PCR (qPCR), immunohistochemistry (also combined with CLARITY) (30), and Western blotting. We compared the distribution of NECABs with that of the four CaBPs restricted to neurons, PV, CB, CR, or Scgn. NECAB+ neurons in the spinal dorsal horn were phenotyped using transgenic mice harboring genetic markers for excitatory [vesicular glutamate transporter 2 (VGLUT2)] (31) or inhibitory [glutamate decarboxylase 67 (GAD67)] (32) cell identities. Finally, the effect of peripheral nerve injury was analyzed.  相似文献   
78.
Bendamustine + rituximab (BR) is the current first-line standard-of-care for chronic lymphocytic leukaemia (CLL) in fit patients aged 66–70 years, whereas chlorambucil + CD20 antibody is recommended in older patients with co-morbidities. This retrospective real-world study investigated whether risk-adapted BR was safe and effective in elderly patients. All 141 CLL patients in the Stockholm region (diagnosed from 2007 to 2016, identified from regional registries) who had received BR as first (n = 84) or later line (n = 57) were analysed. Median age was 72 years, 49% had Binet stage C, 40% had Cumulative Illness Rating Scale (CIRS) score ≥ 6, 20% Eastern Cooperative Oncology Group (ECOG) score 2. None had del(17p). Only 15% of patients aged ≥80 years received full-dose bendamustine and 65% of them postponed rituximab until cycle 2. Corresponding numbers in patients 73–79 years were 21% and 36% and in <73 years, 63% and 33%. Overall response rate was 83% (first line) and 67% (later line) (P < 0·022) equally distributed between age subsets. ECOG, immunoglobulin heavy chain variable region (IGHV) mutational status and cytogenetics, but not treatment line and age, were significant factors on progression-free survival (PFS) in multivariate analysis. Infections and neutropenia/thrombocytopenia (≥grade 3) were similar across age subgroups. In summary, BR was well tolerated even in patients ≥80 years, with similar efficacy and safety as in less old patients, provided that carefully adapted dosing was applied.  相似文献   
79.
Myeloma cells express the idiotype (Id)-specific antigen that may be targeted by Id vaccination. Six patients with stage I IgG myeloma were immunized with the autologous purified M component together with the adjuvant cytokines interleukin 12 (IL-12) alone or in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF). The effect of Id vaccination on circulating clonal tumor B cells was monitored by a real-time allele-specific oligonucleotide polymerase chain reaction method. No other treatment was given. Reduction of blood tumor mass was observed in 4 of 6 patients, with one patient achieving a complete molecular remission in blood. In 3 of these 4 patients an Id-specific T-cell response was induced. In the remaining 2 patients with an unchanged level of blood tumor cells, one patient mounted a T-cell response, whereas the other did not. No significant change in the serum M protein level was noted. Id vaccination may target clonal B cells, suggesting that this strategy might be conducive to achieving tumor control. The clinical significance of these findings remains to be established.  相似文献   
80.
Tumor Biology - Dishevelled (DVL) proteins are components of the Wnt signalling pathways, and increased expression is associated with various malignancies. Information on DVLs in chronic lymphatic...  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