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991.
In order to determine whether the coselection observed between the selection trait (active avoidance behavior) of the Roman High Avoidance (RHA) and Roman Low Avoidance (RLA) rat lines and their neuroendocrine characteristics were genetically determined, we analyzed, in nonsegregating (RHA, RLA, and F1) and segregating (F2 and the two backcrosses) crosses, the inheritance pattern and the phenotypic correlations among behavioral (shuttle-box behavior), physiological (body, adrenal, and thymus weights), and neuroendocrine (corticosterone and prolactin reactivity, catecholamine enzyme activities) variables. Physiological characteristics and enzyme activities have acrucial role in sex dissociation. Avoidance behavior and prolactin reactivity to novel environment remained associated in segregating crosses despite gene rearrangement. They represented the most important variables to differentiate the Roman lines, perhaps sharing a common regulatory mechanism under genetic control.  相似文献   
992.
The lymphocyte proliferative response to recall antigens is lost following HIV infection. We sought to devise a means by which the functional immune status of persons in the early stages of HIV infection could be monitored quantitatively. The response to tetanus toxoid was examined in 45 HIV-infected individuals and 11 controls using conventional lymphocyte proliferative assays concurrently with limiting dilution analysis utilizing the secretion of interleukin-2 as the measure of a response. Our data show that the limiting dilution analysis detects tetanus toxoid-reactive T cells in 80% of those tested, as compared to only 44% by proliferation. However, the frequency of tetanus-reactive T cells in HIV-infected individuals (median frequency = 1/59,156) is decrease five-fold as compared to seronegative controls (median frequency = 1/11,599). Longitudinal studies demonstrated a time-dependent decrease in the frequency of tetanus-specific T cell responses in the HIV-infected individuals. Thus, the limiting dilution analysis is a quantitative approach for detecting antigen-specific T cells in HIV-infected individuals, and may be used to monitor changes in T cell function in HIV infection.  相似文献   
993.
近20年来,有限元分析法在脊柱生物力学研究领域中已得到日益广泛的应用.本文就近10年来国外学者用有限元法研究脊柱生物力学的新进展作以综述.详细介绍了椎体、后部结构、间盘、韧带、肌肉组织在生理及病理情况下的生物力学特性,及不同术式、内固定器械对脊柱生物力学的影响;介绍了用有限元法研究某些疾病发病的力学机制的新成果;展望了有限元法应用于脊柱生物力学研究的前景.  相似文献   
994.
Su YN  Lee CN  Hung CC  Chen CA  Cheng WF  Tsao PN  Yu CL  Hsieh FJ 《Human mutation》2003,22(4):326-336
Beta-thalassemia is a common inherited disease, resulting from one or more of a total of more than 200 different mutations in the beta-globin gene (HBB). Efficient and reliable mutation-screening methods are essential in order to establish appropriate prevention programs for at-risk populations based upon a molecular diagnosis. We have developed a rapid and highly-specific mutation screening test for the diagnosis of beta-thalassemia by coupling heteroduplex and primer-extension analysis based on the denaturing high performance liquid chromatography (DHPLC) system. A total of 161 healthy heterozygous Taiwanese carriers featuring 10 different HBB mutations and 30 patients exhibiting 12 different compound heterozygous or homozygous HBB mutations were subjected to DHPLC. The elution profile for the heteroduplex analysis of DHPLC could be successfully used to identify the common disease-causing mutations of HBB. To further confirm the sequence variants, we developed a technique combining multiplex primer-extension analysis coupled with DHPLC for the genotyping of eight common disease-causing mutations in the HBB gene. Overall, by coupling heteroduplex and primer-extension analysis based upon DHPLC, we were able to unambiguously identify the most-common beta-thalassemia mutations corresponding to more than 99% of HBB alleles among the Taiwanese population. In conclusion, compared to classic approaches to mutation screening for this malady, we suggest that DHPLC is an excellent technique to be applied to the genetic screening of prenatal and postnatal individuals as a part of a diagnosis program for beta-thalassemia and provides a more-efficient, economic, and sensitive means to undertake such a screening program.  相似文献   
995.
皮肤穿支血管的解剖学研究   总被引:18,自引:6,他引:18  
目的:对全身皮肤血管区域进行定性和定量分析,确定全身皮肤穿支血管的位置、数量、口径、穿支蒂的长度、类型、来源血管以及穿支所供应皮肤的面积,为穿支皮瓣提供血管解剖基础。方法:选用10具新鲜尸体,采用改良氧化铅一明胶灌注技术进行动脉灌注。将每个口径大于0.5mm的穿支血管进行解剖并记录。拍摄X线片以显示皮肤内血管的形态和分布。定量数据分析包括全身各部位的穿支血管的数量、口径、类型及其供应区域的面积。结果:发现全身128支起源血管发出440支穿支供应皮肤。其中肌皮穿支与肌间隔穿支之比为3:2。穿支平均直径为0.7mm。穿支血管的分布规律如下:①躯干皮肤的血供主要来自肌皮穿支,这些穿支在皮肤内的走行距离和分布范围大于肢体皮肤的穿支。②肢体皮肤的血供主要来自肌间隙穿支血管,主要分布在深筋膜表面,皮神经和浅静脉周围穿支之间形成链式血管吻合。③单位面积的穿支数量与皮肤的移动程度成反比,穿支的口径大小和穿支在皮肤内走行距离与皮肤移动度成正比,与穿支的供应面积成正比。结论:本研究提供详细的皮肤穿支血管解剖数据,为临床设计应用穿支皮瓣提供解剖学依据。  相似文献   
996.
心电信号预处理与心电信号分析   总被引:2,自引:0,他引:2  
本文介绍了在一种便携式心电监护仪器中是如何对心电数据进行预处理和智能分析的.为了适应便携式仪器的特征,我们在心电信号预处理中采用了FFT滤波和滑动平均滤波的方法去除各种干扰并使图像得以平滑,同时采用了差分阈值法提取特征点,考虑到监护仪器的实用性,在心电信号分析阶段,我们采用了分析特征间期异常情况的方法来替代对病症的智能诊断功能。  相似文献   
997.
Data are presented on the effects of generalized tonic-clonic seizures on the structure of the one-day sleep-waking cycle in Krushinskii-Molodkina (KM) rats, which have a genetic predisposition to audiogenic convulsions. Spectral and correlation analysis of EEG activity in the hippocampus, caudate nucleus, medial central nucleus of the thalamus, and in the somatosensory, visual, and auditory regions of the cortex of these animals was carried out for time intervals before and after convulsions. After seizures, rats showed a prolonged (up to 3.5 h) reduction in fast-wave sleep (FWS) with no subsequent compensatory increase in this shase in the sleep-waking cycle, while a disturbance in slow-wave sleep (SWS) was minor and short-lived (not more than 2 h). It is suggested that generalized paroxysmal attacks predominantly involve disorganization of the function of the systems regulating FWS, while the synchronizing mechanisms of the brain, responsible for SWS, are affected to a lesser extent. Laboratory of the Evolution of Sleep and Waking (Director G. A. Oganesyan), I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 81, No. 10, pp. 1–8, October, 1995.  相似文献   
998.
R.L. Clarke   《Biomaterials》1989,10(9):630-633
Four heterocyclic methacrylates were investigated with respect to their loss tangent and activation energy using a dynamic mechanical thermal analyser over a limited frequency range of 0.033 to 90 Hz. The linear regression lines obtained showed an Arrhenius-type relationship between transition temperature and frequency. Their low activation energies in comparison to poly (methyl methacrylate) and bis-phenol A based methacrylates was thought to be a direct consequence of their low molecular weights.  相似文献   
999.
Recent advances in the study of evoked responses settled a definition of transient and steady-state visual evoked responses (VER) and discovered the existence of Temporal Frequency Regions in humans. This paper reports data from visual responses evoked by low and high frequency stimuli. White flashes were performed in albino Sprague Dawley rats from 7 to 90 days of age. Frequency analysis technique offered the possibility to evaluate the amplitude parameters and their variations dependent on intensity of luminance and on development. The responses suggested the existence of two temporal frequency regions in the rat: a first one at about 8 Hz, related to high frequencies of EEG, a second one at frequencies ranging from 12 to 24 Hz, related to luminance sensitivity. The development of the second region is correspondent to the complete development of transient VER parameters.  相似文献   
1000.
The family Herpesviridae comprises at least 100 herpesviruses. Numerous human and animal pathogenic herpesviruses have been identified so far, including Cercopithecine herpesvirus 1 (CeHV-1). This virus is a member of the subfamily Alphaherpesvirinae and is the most hazardous herpesvirus to man. CeHV-1 is also known as B-virus or monkey B virus and as Herpesvirus simiae. In order to gain more genetic information, the viral DNA polymerase (DPOL) gene was identified using polymerase chain reaction (PCR) and DNA nucleotide sequence analysis. The deduced amino acid sequence contains the motifs and signatures that are typical for the B-family of DPOLs. The DPOL gene of CeHV-1 was found to be a suitable target for the specific and rapid identification of the Cercopithecine herpesvirus 1 infection by PCR technology. Comparative analysis of the DNA sequences of the DPOL gene loci of CeHV-1, Human herpesvirus 1 and 2 (HHV-1 and HHV-2), and other herpesviruses was carried out for determination of unique genomic regions of the individual DPOL genes. A primer set of 12 primers was used for screening the DNA of CeHV-1, HHV-1, and HHV-2 by detailed PCR. It was found that six out of twelve primer combinations are able to detect specifically the CeHV-1 genome without cross reactivity with the genome of HHV-1 and/or HHV-2. The specificity of the individual amplified DNA fragments was confirmed by DNA nucleotide sequence analysis. The results of these studies indicate that the six primer combinations of the specific CeHV-1 DPOL primer set is the method of choice for a rapid, precise and specific identification of a CeHV-1 infection by PCR. Due to the fact that this specific CeHV-1 DPOL primer set does not amplify any DNAs of HHV-1 or HHV-2 genome this technology is stressing and can be successfully used unlimited and more credible in all laboratories with PCR technical facility routinely for detection of a CeHV-1 infection in vivo or in vitro.The GenBank Accession No. of the sequence of DNA polymerase gene of Cercopithecine herpesvirus 1 (CeHV-1) reported in this study is AY568415, DPOL protein ID AAT67222; nuclear phosphoprotein ID AAT67223  相似文献   
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