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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.
Subjective tinnitus is the most common type of tinnitus, which is the manifestation of pathological activities in the brain. It happens in a substantial portion of the general population and brings significant burden to the society. Severe subjective tinnitus can lead to depression and insomnia and severely affects patients’ quality of life. However, due to poor understanding of its etiology and pathogenesis, treatment of subjective tinnitus remains challenging. In recent decades, a growing number of studies have shown that subjective tinnitus is related to lesion-induced neural plasticity of auditory and non-auditory central systems. This article reviews cellular mechanisms of neural plasticity in subjective tinnitus to provide further understanding of its pathogenesis.  相似文献   
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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   
5.
Prediction of periodic event timing is an important function for everyday activities, while the exact neural mechanism remains unclear. Previous studies in nonhuman primates have demonstrated that neurons in the cerebellar dentate nucleus and those in the caudate nucleus exhibit periodic firing modulation when the animals attempt to detect a single omission of isochronous repetitive audiovisual stimuli. To understand how these subcortical signals are sent and processed through the thalamocortical pathways, we examined single-neuron activities in the central thalamus of two macaque monkeys (one female and one male). We found that three types of neurons responded to each stimulus in the sequence in the absence of movements. Reactive-type neurons showed sensory adaptation and gradually waned the transient response to each stimulus. Predictive-type neurons steadily increased the magnitude of the suppressive response, similar to neurons previously reported in the cerebellum. Switch-type neurons initially showed a transient response, but after several cycles, the direction of firing modulation reversed and the activity decreased for each repetitive stimulus. The time course of Switch-type activity was well explained by the weighted sum of activities of the other types of neurons. Furthermore, for only Switch-type neurons the activity just before stimulus omission significantly correlated with behavioral latency, indicating that this type of neuron may carry a more advanced signal in the system detecting stimulus omission. These results suggest that the central thalamus may transmit integrated signals to the cerebral cortex for temporal information processing, which are necessary to accurately predict rhythmic event timing.SIGNIFICANCE STATEMENT Several cortical and subcortical regions are involved in temporal information processing, and the thalamus will play a role in functionally linking them. The present study aimed to clarify how the paralaminar part of the thalamus transmits and modifies signals for temporal prediction of rhythmic events. Three types of thalamic neurons exhibited periodic activity when monkeys attempted to detect a single omission of isochronous repetitive stimuli. The activity of one type of neuron correlated with the behavioral latency and appeared to be generated by integrating the signals carried by the other types of neurons. Our results revealed the neuronal signals in the thalamus for temporal prediction of sensory events, providing a clue to elucidate information processing in the thalamocortical pathways.  相似文献   
6.
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   
7.
为了保证电子设备在复杂的电磁环境中正常运行,需要对其进行电磁防护。传统的电磁防护方法尽管已取得较好的防护效果,但是还存在一定的不足。为了弥补传统电磁防护的不足,本研究提出基于神经抗扰机制的电磁仿生方法,并具体提出基于神经元抗扰机制的新型方波发生器。采用最接近生物神经元电生理活动的数学模型Hodgkin-Huxley模型对新型方波发生器进行设计。利用Matlab的Simulink工具箱搭建方波发生器的仿真程序,分析方波信号占空比的特性,得到模型参数对占空比的影响程度。基于田口方法的望小特性优化方波发生器的模型参数,从而得到特定占空比。该方波发生器可为智能电子设备提供稳定可靠的方波信号。  相似文献   
8.
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   
9.
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   
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