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1.
[目的]观察电针对完全弗氏佐剂(complete Freund‘s adjuvant,CFA)诱导的慢性炎性痛模型大鼠机械痛阈(paw withdrawal threshold,PWTs)、焦虑行为,以及双侧海马角1(Cornu Ammonis 1,CA1)、海马角3(Cornu Ammonis 3,CA3)、齿状回(Dentate Gyrus,DG)中神经肽Y(neuropeptide Y,NPY)、小清蛋白(parvalbumin,PV)、生长抑制素(somatostatin,SOM)、谷氨酸脱羧酶65/67(glutamic acid decarboxylase 65/67,GAD65/67)及原癌基因蛋白(cellular protooncogene Fos,c-Fos)表达的影响,探讨其可能机制。 [方法] 将32只健康雄性SD大鼠随机分为空白对照组、模型对照组、电针治疗组和假电针治疗组,每组8只,并对空白对照组以外的其他3组足底注射CFA,建立大鼠慢性炎性痛模型。于造模后26 d分别对电针治疗组和假电针治疗组进行电针和假电针干预,并观察各组大鼠的PWTs及高架O迷宫(elevated zero maze,EZM)中的焦虑行为。用免疫荧光法检测CA1、CA3和DG区NPY、PV、SOM、GAD65/67及c-Fos的阳性细胞表达。[结果] 造模后1 d,模型对照组、电针治疗组和假电针治疗组的PWTs显著降低,并在整个实验过程中显著低于空白对照组(P<0.01);在电针治疗第3天,电针治疗组大鼠的PWTs相较模型对照组和假电针治疗组显著升高(P<0.01)。在EZM中,与空白对照组比较,模型对照组大鼠的开放臂运动距离、开放臂停留时间和开放臂进入次数显著减低(P<0.01),电针干预后可改善上述指标,而假电针无作用(P>0.05)。与空白对照组比较,模型对照组双侧CA1、CA3、DG区NPY阳性细胞表达增多(P<0.01,P<0.01,P<0.05),c-Fos阳性细胞表达减少(P<0.01,P<0.05,P<0.01);电针干预后,电针治疗组大鼠双侧CA1、DG区、患侧CA3区NPY阳性细胞表达较模型对照组减少(P<0.01),假电针无此作用(P>0.05)。双侧CA1、CA3和DG区,四组大鼠PV、SOM以及双侧CA1、CA3区GAD65/67阳性细胞表达或阳性面积差异均无统计学意义(P>0.05)。 [结论] 电针干预能改善CFA大鼠的疼痛及其相关焦虑行为,该作用可能与增加大鼠海马CA1、CA3和DG区NPY的阳性细胞表达有关。  相似文献   
2.
BackgroundRelational memory, the ability to bind information into complex memories, is moderately impaired in early psychosis and severely impaired in chronic schizophrenia, suggesting relational memory may worsen throughout the course of illness. MethodsWe examined relational memory in 66 early psychosis patients and 64 healthy control subjects, with 59 patients and 52 control subjects assessed longitudinally at baseline and 2-year follow-up. Relational memory was assessed with 2 complementary tasks, to test how individuals learn relationships between items (face-scene binding task) and make inferences about trained relationships (associative inference task).ResultsThe early psychosis group showed impaired relational memory in both tasks relative to the healthy control group. The ability to learn relationships between items remained impaired in early psychosis patients, while the ability to make inferences about trained relationships improved, although never reaching the level of healthy control performance. Early psychosis patients who did not progress to schizophrenia at follow-up had better relational memory than patients who did.ConclusionsRelational memory impairments, some of which improve and are less severe in patients who do not progress to schizophrenia, are a target for intervention in early psychosis.  相似文献   
3.
Studies have shown relationships between white matter abnormalities and cognitive dysfunction in myotonic dystrophy type 1 (DM1), but comprehensive analysis of potential structure–function relationships are lacking. Fifty adult‐onset DM1 individuals (33 female) and 68 unaffected adults (45 female) completed the Wechsler Adult Intelligence Scale‐IV (WAIS‐IV) to determine the levels and patterns of intellectual functioning. Neuroimages were acquired with a 3T scanner and were processed with BrainsTools. Regional brain volumes (regions of interest, ROIs) were adjusted for inter‐scanner variation and intracranial volume. Linear regression models were conducted to assess if group by ROI interaction terms significantly predicted WAIS‐IV composite scores. Models were adjusted for age and sex. The DM1 group had lower Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index (PSI) scores than the unaffected group (PRI t(113) = ?3.28, p = 0.0014; WMI t(114) = ?3.49, p = 0.0007; PSI t(114) = ?2.98, p = 0.0035). The group by hippocampus interaction term was significant for both PRI and PSI (PRI (t(111) = ?2.82, p = 0.0057; PSI (t(112) = ?2.87, p = 0.0049)). There was an inverse association between hippocampal volume and both PRI and PSI in the DM1 group (the higher the volume, the lower the intelligence quotient scores), but no such association was observed in the unaffected group. Enlarged hippocampal volume may underlie some aspects of cognitive dysfunction in adult‐onset DM1, suggesting that increased volume of the hippocampus may be pathological.  相似文献   
4.
The striatonigral and olivopontocerebellar systems are known to be vulnerable in multiple system atrophy (MSA), showing neuronal loss, astrogliosis, and alpha-synuclein-immunoreactive inclusions. MSA patients who displayed abundant neuronal cytoplasmic inclusions (NCIs) in the regions other than the striatonigral or olivopontocerebellar system have occasionally been diagnosed with variants of MSA. In this study, we report clinical and pathologic findings of MSA patients characterized by prominent pathologic involvement of the hippocampus. We assessed 146 consecutively autopsied MSA patients. Semi-quantitative analysis of anti-alpha-synuclein immunohistochemistry revealed that 12 of 146 patients (8.2%) had severe NCIs in two or more of the following areas: the hippocampal granule cells, cornu ammonis areas, parahippocampal gyrus, and amygdala. In contrast, the remaining 134 patients did not show severe NCIs in any of these regions. Patients with severe hippocampal involvement showed a higher representation of women (nine women/three men; Fisher's exact test, p = 0.0324), longer disease duration (13.1 ± 5.9 years; Mann–Whitney U-test, p = 0.000157), higher prevalence of cognitive impairment (four patients; Fisher's exact test, p = 0.0222), and lower brain weight (1070.3 ± 168.6 g; Mann–Whitney U-test, p = 0.00911) than other patients. The hippocampal granule cells and cornu ammonis area 1/subiculum almost always showed severe NCIs. The NCIs appeared to be ring-shaped or neurofibrillary tangle-like, fibrous configurations. Three of 12 patients also had dense, round-shaped NCIs that were morphologically similar to pick bodies. The patients with Pick body-like inclusions showed more severe atrophy of the medial temporal lobes and broader spreading of NCIs than those without. Immunohistochemistry for hyperphosphorylated tau and phosphorylated TDP-43 revealed minimal aggregations in the hippocampus of the hippocampal MSA patients. Our observations suggest a pathological variant of MSA that is characterized by severe involvement of hippocampal neurons. This phenotype may reinforce the importance of neuronal alpha-synucleinopathy in the pathogenesis of MSA.  相似文献   
5.
目的:利用基于深度学习的人工智能算法,结合头颅MRI和CT的多模态影像,开发海马结构自动勾画技术,为头颅放疗过程中海马体的保护提供高效、准确的自动勾画方法。方法:收集清华大学第一附属医院放疗科从2020年1月~12月就诊的40例脑转移癌患者的定位头颅CT及MRI影像,分别在CT图像、CT-MRI配准图像的两个数据集上训练3D U-Net、3D U-Net Cascade、3D BUC-Net 3个深度学习模型,计算3个模型自动分割的左右海马体与对应的人工标注之间的Dice相似系数(DSC)和95%豪斯多夫距离(95 HD),以及两者的体积作为模型的分割准确性的评估,并且以对同一大小patch图像的自动分割耗时作为模型效率的评估。结果:引入MRI图像信息对左右海马的自动分割精度有明显的提升;模型3D BUC-Net在CT-MRI数据集上对左右海马体的自动分割都取得最好分割结果(DSC:0.900±0.017,0.882±0.026;95HD:0.792±0.084,0.823±0.093),而且该模型的分割效率更高。结论:模型3D BUC-Net能在多模态影像上实现高效、准确的海马区的自动勾画,为头颅放疗过程中海马区的保护提供方便。  相似文献   
6.
目的:研究螺旋断层放疗(HT)在全脑照射保护海马回区(HS-WBRT)计划中各项参数对结果的影响。方法:选取8例行HS-WBRT的患者,在瓦里安Eclipse 13.5医生工作站进行靶区和危及器官的勾画,左右海马基于CT图像和MR图像融合勾画,同时外扩5 mm作为海马减量区,靶区为全脑减去海马回区均匀外扩5 mm的区域,危及器官包括海马回区、海马减量区、眼球和晶体。将勾画好的结构和图像传至HT物理师工作站进行计划设计,处方剂量25 Gy/10 F,射野宽度(FW)分别选择1.0、2.5、5.0 cm,螺距(Pitch)分别选择0.215、0.287、0.430,调制因子(MF)分别选择1.5、2.0、2.5、3.0、3.5、4.0、4.5、5.0,剂量计算网格(0.195 cm×0.195 cm),其余计划参数都保持一致,分别设计不同组合参数的计划。最后统计分析不同计划参数对靶区及危及器官的剂量分布及执行效率的影响。结果:使用不同参数制作的计划均满足临床要求。通过比较不同FW、Pitch和MF对靶区及危及器官的影响,FW和MF影响最大,Pitch无影响。从计划质量考虑,FW为1.0 cm时剂量分布最佳,FW为2.5 cm时次之,FW为5 cm时最差;从治疗效率考虑,FW为5 cm时效率最高,FW为2.5 cm时效率次之,FW为1.0 cm时最差。当FW为1.0 cm时,MF选择2.5左右最佳;当FW为2.5 cm,MF选择4左右最佳;当FW为5 cm时,MF选择4左右最佳;此时减小MF会降低计划质量,而增大MF对改善剂量分布无意义,仅会增加治疗出束时间,降低治疗效率。结论:在进行HS-WBRT的计划设计中,需根据临床要求选择合适的计划参数。当临床侧重计划质量时,可选择FW为1 cm或2.5 cm,此时MF选择对应的2.5左右或4左右最佳;当侧重治疗效率时,可选择FW为5.0 cm或2.5 cm,此时MF选择4左右最佳;当兼顾计划质量和执行效率时,可选择FW为2.5 cm,此时MF选择4左右最佳,实现计划质量和治疗效率的平衡。  相似文献   
7.
The locus coeruleus (LC) contains the majority of central noradrenergic neurons sending wide projections throughout the entire CNS. The LC is considered to be essential for multiple key brain functions including arousal, attention and adaptive stress responses as well as higher cognitive functions and memory. Electrophysiological studies of LC neurons have identified several characteristic functional features such as low‐frequency pacemaker activity with broad action potentials, transient high‐frequency burst discharges in response to salient stimuli and an apparently homogeneous inhibition of firing by activation of somatodendritic α2 autoreceptors (α2AR). While stress‐mediated plasticity of the α2AR response has been described, it is currently unclear whether different LC neurons projecting to distinct axonal targets display differences in α2AR function. Using fluorescent beads‐mediated retrograde tracing in adult C57Bl6/N mice, we compared the anatomical distributions and functional in vitro properties of identified LC neurons projecting either to medial prefrontal cortex, hippocampus or cerebellum. The functional in vitro analysis of LC neurons confirmed their mostly uniform functional properties regarding action potential generation and pacemaker firing. However, we identified significant differences in tonic and evoked α2AR‐mediated responses. While hippocampal‐projecting LC neurons were partially inhibited by endogenous levels of norepinephrine and almost completely silenced by application of saturating concentrations of the α2 agonist clonidine, prefrontal‐projecting LC neurons were not affected by endogenous levels of norepinephrine and only partially inhibited by saturating concentrations of clonidine. Thus, we identified a limited α2AR control of electrical activity for prefrontal‐projecting LC neurons indicative of functional heterogeneity in the LC‐noradrenergic system.  相似文献   
8.
9.
The hippocampus of rodents undergoes structural remodeling throughout adulthood, including the addition of new neurons. Adult neurogenesis is sensitive to environmental enrichment and stress. Microglia, the brain's resident immune cells, are involved in adult neurogenesis by engulfing dying new neurons. While previous studies using laboratory environmental enrichment have investigated alterations in brain structure and function, they do not provide an adequate reflection of living in the wild, in which stress and environmental instability are common. Here, we compared mice living in standard laboratory settings to mice living in outdoor enclosures to assess the complex interactions among environment, gut infection, and hippocampal plasticity. We infected mice with parasitic worms and studied their effects on adult neurogenesis, microglia, and functions associated with the hippocampus, including cognition and anxiety regulation. We found an increase in immature neuron numbers of mice living in outdoor enclosures regardless of infection. While outdoor living prevented increases in microglial reactivity induced by infection in both the dorsal and ventral hippocampus, outdoor mice with infection had fewer microglia and microglial processes in the ventral hippocampus. We observed no differences in cognitive performance on the hippocampus‐dependent object location task between infected and uninfected mice living in either setting. However, we found that infection caused an increase in anxiety‐like behavior in the open field test but only in outdoor mice. These findings suggest that living conditions, as well as gut infection, interact to produce complex effects on brain structure and function.  相似文献   
10.
Dietary omega‐3 fatty acids accumulate and are actively retained in central nervous system membranes, mainly in synapses, dendrites and photoreceptors. Despite this selective enrichment, their impact on synaptic function and plasticity has not been fully determined at the molecular level. In this study, we explored the impact of omega‐3 fatty acid deficiency on synaptic function in the hippocampus. Dietary omega‐3 fatty acid deficiency for 5 months after weaning led to a 65% reduction in the concentration of docosahexaenoic acid in whole brain synaptosomal phospholipids with no impact on global dopaminergic or serotonergic turnover. We observed reduced concentrations of glutamate receptor subunits, including GluA1, GluA2 and NR2B, and synaptic vesicle proteins synaptophysin and synaptotagmin 1 in hippocampal synaptosomes of omega‐3 fatty acid‐deficient mice as compared to the omega‐3 fatty acid rich group. In contrast, an increased concentration of neuronal inositol 1,4,5‐trisphosphate‐receptor (IP3‐R) was observed in the deficient group. Furthermore, omega‐3 fatty acid deficiency reduced the long‐term potentiation (LTP) in stratum oriens of the hippocampal CA1 area, but not in stratum radiatum. Thus, omega‐3 fatty acids seem to have specific effects in distinct subsets of glutamatergic synapses, suggesting specific molecular interactions in addition to altering plasma membrane properties on a more global scale.  相似文献   
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