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61.
62.
The integrity of the sensory nervous system in the anal canals of chronically constipated children was investigated using
evoked potential techniques examining cerebral and spinal evoked potentials from the lower extremities and anal canal. Stimulation
of the posterior tibial nerve produced no significant difference in the parameters of spinal and cerebral evoked potentials
between 18 controls and 12 chronically constipated chidren. However, stimulation of the anal canal resulted in evoked potentials
related to the age and/or consciousness level of the control children. Reproducible cerebral responses were obtained only
from nine of these control children, all aged over 4 years, who were examined while awake without sedatives. A typical response
was characterized by a polyphasic wave occurring with an onset latency of 79.4± 27.7ms (mean ±SD). In the 12 chronically constipated
children, the 5 sedated patients examined while asleep did not show any reproducible potential, as in the controls. However,
in the remaining 7 children examined while awake, the occurrence of the anal canal evoked potential was significantly reduced,
and only two exhibited a cerebral response. These findings suggest that rectal mucosal perception of the intraluminal stimuli
might be disturbed in some children with chronic constipation. 相似文献
63.
OBJECTIVE: We investigate the synaptic factor for the recovery function of evoked responses using a repetitive stimulation technique. METHODS: Somatosensory evoked cortical magnetic field (SEF) was recorded following stimulation of the median nerve using single to 6-train stimulation in 8 healthy subjects. The SEF responses after each stimulus in the train stimulation were extracted by subtraction of the waveforms. RESULTS: An attenuation of the SEF components was recognized after the second of the stimuli, but there was no significant attenuation with the third or later stimulations. The root mean square (RMS) of the 1M (peak latency at 20 ms after stimulation) and 4M (70 ms) components were smaller than that of the single stimulation during the train stimulation, while the 2M (30 ms) and 3M (45 ms) components were not attenuated, but the 3M was facilitated at the fourth to sixth stimulation. CONCLUSION: The synaptic factor was not responsible for the attenuation of the SEF components during repetitive stimulation in healthy subjects. The SEF change disclosed a functional difference among the SEF components during the train stimulation, especially among the later components. 相似文献
64.
本实验观察105 dB—125 dB(声压级,SPL)白噪声暴露20min 对豚鼠耳蜗直流电位(EP)的影响.发现随着噪声强度的增加,EP 发生不同形式的改变:115 dB噪声使 P—EP 增大,而125 dB 则使其减小,但各组负 EP(N—EP)变化不大。提示有血管纹功能从代偿性增强到失代偿的变化过程。本文还利用几种钾离子通道阻断剂对EP 改变的通道机制作了探讨。 相似文献
65.
Yang-Chyuan Chang Ching-Ying Yeh Jung-Der Wang 《American journal of industrial medicine》1995,27(2):271-279
Pattern visual, brainstem auditory, and somatosensory evoked potential (EP) studies were performed on 26 chloralkali workers. The intensity of mercury vapor exposure in these workers was estimated from the individual working history. Mercury levels in blood, urine, and hair were determined with atomic absorption spectrometry. The EP findings were compared with those from individually matched normal subjects. In brainstem auditory and somatosensory EP studies, prolonged neural conduction times in the central nervous system (CNS) were found in workers exposed to mercury vapor. In the pattern visual EP study, mercury workers had higher interpeak amplitudes. Findings of this study suggested that chronic exposure to mercury vapor would affect the CNS functions. A multimodality EP study is a useful adjunct in evaluation of chronic mercury neurotoxicity, especially in an epidemiological study. 相似文献
66.
The Na+–Ca2+ exchange (NCX) system plays a pivotal role in regulating intracellular Ca2+ concentration in cardiomyocytes, neuronal cells, kidney and a variety of other cells. It performs a particularly important function in regulating cardiac contractility and electrical activity. One of the leading NCX inhibitors is KB‐R9743 (KBR) that appears to exhibit selectivity for Ca2+‐influx‐mode NCX activity (reverse mode of NCX). In this article we reviewed pharmacology of KBR and provide a brief summary of studies with other NCX inhibitors, such as SEA0400 (SEA) and SN‐6 (SN). Potential clinical usefulness of KBR and other NCX inhibitors is still controversial but the reviewed findings may be helpful in designing more selective and clinically useful NCX inhibitors for the treatment of cardiac, neuronal and kidney diseases. 相似文献
67.
目的 :观察神经生长液 ( NGD)及神经再生素 ( NRF)修复大鼠坐骨神经缺损的效果。方法 :用生理盐水( NS)、NRF桥接以及 NRF桥接 +口服 NGD修复大鼠坐骨神经缺损 ,术后 12周检测大鼠坐骨神经干动作电位传导速度及肌电图。结果 :行为方面 NGD+ NRF组比 NS组恢复早 ,NS组、NRF组、NRF+ NGD组神经干动作电位传导速度的平均值分别为 5 .72 0 m/ s、16 .5 14 m/ s、2 1.310 m/ s。NS组与 NGD+ NRF组的神经干动作电位传导速度经统计学分析有显著性差异 ( P<0 .0 1)。NGD+ NRF组与 NS组的肌电图比较 ,前者的潜伏期短、峰谷值大、运动神经传导速度快。结论 :NGD+ NRF具有良好促进神经再生作用 相似文献
68.
A.V. Chistyakov J.F. Soustiel H. Hafner M. Elron M. Feinsod 《Acta neurochirurgica》1998,140(5):467-462
Summary
This study attempts to find out whether the motor evoked potential (MEP) elicited by single pulse and slow-rate (1 Hz) repetitive
transcranial magnetic stimulation (TMS) can disclose concealed subclinical impairments in the cerebral motor system of patients
with minor head injury.
The motor response to single pulse TMS (STMS) of the patient groups was characterized by significantly higher threshold compared
with that of the control group. The central motor conduction time, as well as the peripheral conduction time were normal in
all patients pointing to cortical impairment.
Two main patterns of MEP changes in response to repetitive TMS (RTMS) were observed in the patient group. A. – progressive
decrease of the MEP amplitude throughout the stimulation session to a near complete abolition. B. – irregularity of the amplitude
and the waveform of the MEP in a chaotic form. The MEP latency remained stable during the whole stimulation session. The MEP
abnormalities recovered gradually over the period of a few months.
The higher threshold of the motor response to STMS and the abnormal patterns of the MEP to RTMS seem to reflect transient
impairment of cortical excitability or “cortical fatigue” in patients who sustained minor head injures. Further study is needed
to evaluated the extent and the pathophysiological mechanisms of the central nervous system fatigue phenomenon following head
injury. 相似文献
69.
Sven Erik G. Nilsson Björn E. Andersson 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):313-325
A set-up for D.C. recordings of slow ocular potentials such as the c-wave of the electroretinogram (ERG) as well as the fast oscillation (FO), the light peak (LP) and the dark trough (DT) in both clinical and experimental work is described. It includes matched calomel half-cells connected by saline-agar bridges to a corneal contact lens on the eye and a reference chamber on the forehead, a low-drift differential-input D.C. amplifier, an A/D converter, a computer, a thermoprinter, a flexible disc memory, a plotter, and a device for light stimulation controlled by the computer.Examples of the usefulness of the set-up in clinical work are shown in the form of D.C. c-wave ERGs of normal subjects as well as of patients with vitelliform macular degeneration, choriocapillaris atrophy, and retinitis pigmentosa. The direct corneal recording of the FO and LP is demonstrated as well. The different origins of the standing potential (SP) of the eye, the ERG c-wave, the FO and the LP are reviewed briefly. 相似文献
70.
The burden of injuries is underestimated to an even greater extent in developing countries than in industrialized countries. The objective of this paper is to analyze injuries and diseases in the monitored work place of the world's largest tin mining operation in Yunnan, South China. 相似文献