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21.
22.
增生性玻璃体视网膜病变基质金属蛋白酶的定量研究 总被引:5,自引:0,他引:5
目的:研究增生性玻璃体视网膜病变(proliferative vitreoretinopathy,PVR)玻璃体中基质金属蛋白酶(matrix metalloproteinases,MMPs)的表达,探讨MMPs在PVR病理过程中的作用。方法:PVR患者采用标准三切口巩膜扁平部玻璃体切割术(pars plana vitrectomy,PPV),取未稀释的玻璃体21只眼,PPV术后复发的玻璃体腔液20只眼,意外死亡的正常人玻璃体10只眼,采用明胶酶谱分析法定量分析MMP-2和MMP-9活性水平。结果:PVR玻璃体有MMP-2活性水平增高,与正常玻璃体比较差异有显著性意义(P<0.05)。21眼PVR玻璃体中13只眼有MMP-9活性水平增高,平均(171.52±13.17)扫描单位。20眼PPV术后PVR复发的玻璃体腔液19只眼有MMP-9活性水平增高,平均(156.01±37.21)扫描单位。正常人玻璃体无MMP-9的表达。结论:PVR玻璃体有MMP-2和MMP-9活性水平增高,MMP-9活性水平增高可能与术后PVR复发有关。眼科学报2003;19:130-132。 相似文献
23.
研究了流化床喷雾制粒机的起始流化速率,粉粒平稳流化及其控制方法,喷雾制粒机理和骤变失稳现象,指出起始流化速度的实验值远大于理论值,但是可以通过对床层压降的监控,实现平稳流化的操作控制,颗粒以团骤方式长大,而温骤变失稳是本文流化制粒失效的主要形式,讨论了多种过程参量对制粒和骤变失稳的影响,其结果有助于指导实际生产。 相似文献
24.
作者以1%乙酸冲洗SD大鼠子宫内膜,获得子宫内膜酸溶性提取物。利用琼脂糖弥散法和电泳凝胶琼脂糖弥散法抗菌试验发现,子宫内膜提取物有三条主蛋白带对致病性大肠杆菌ML-35P耐药株有强抗菌活性,这三条抗菌蛋白带命名为RatUP-1,RatUP-2和RatUP-3,分别占子宫内膜提取物总蛋白量的4.5%,5.7%和6.6%。虽然提取物存在溶菌的活性,但其含量甚微,在AU一PAGE图谱上亦未能显现溶菌酶条带。本实验的结果提示子宫内膜合成一类抗菌多肽,可能在子宫抗菌机制中发挥重要作用。 相似文献
25.
Mechanical or thermal injury to one of a pair of parabiotic rats with a crossed circulation but separate innervation was followed by the development of a state resembling shock in the other partner. Microcirculatory changes characteristic of either traumatic or burn shock developed in its mesentery under these circumstances. The results are interpreted as evidence in support of a humoral rather than a nervous mechanism of the microcirculatory disturbances in these types of shock.Laboratory of Pathophysiology of Extremal States, Research Institute of General Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 10, pp. 416–418, October, 1978. 相似文献
26.
Finegold I 《Clinical reviews in allergy & immunology》2004,27(2):75-82
Recent results of allergen immunotherapy research have continued to validate efficacy and have also demonstrated a truly preventive
aspect for this treatment. This review summarizes the basic principles of effective allergen immunotherapy and highlights
some of the advances that have been published in the past year. These studies show that allergen immunotherapy, when done
appropriately and properly, not only causes a decrease in symptoms and use of medication as well as an improved quality of
life, but that the progression of disease from allergic rhinitis to asthma is substantially decreased and the development
of new allergies is diminished. In addition, laboratory studies continue to demonstrate significant changes in the immune
system with a shift in the immune pathway from TH2 toward a TH1 response. The impact of anti-IgE as a therapeutic agent with allergen immunotherapy is also be reviewed. 相似文献
27.
S. P. Perrett 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1998,121(2):115-124
Little is known about mechanisms used by the nervous system to encode time. In light of recent evidence, cerebellar cortex
involvement in the learned timing of conditioned eyelid responses shows promise as an area of investigation into neural timing
mechanisms. Lesion studies indicate that the cerebellar cortex is necessary for response timing, but do not rule out the possibility
that response timing is encoded afferent to the cerebellum. To differentiate between precerebellar and cerebellar cortical
timing mechanisms, rabbits were trained by pairing direct stimulation of mossy fibers in the cerebellum as the conditioned
stimulus (CS) with an eyeshock unconditioned stimulus (US). We find that individual animals can produce diffently timed conditioned
responses when trained with a mossy fiber CS that has been paired with the US at various interstimulus intervals. The fact
that differently timed responses can be conditioned using constant-frequency stimulation of an invariant subset of mossy fibers
as the CS suggests that timing information in the afferent input to the cerebellum is not essential. Two rabbits trained with
single-pulse stimulation in the cerebellum as the CS also learned differently timed conditioned responses; suggesting that
fiber recruitment during a stimulus train does not convey the necessary temporal coding to the cerebellar cortex. Together
with the lesion data, these findings suggest that the learned timing of conditioned eyelid responses occurs in the cerebellar
cortex.
Received: 25 August 1997 / Accepted: 12 January 1998 相似文献
28.
Left and right, palmar and dorsal skin conductance levels (SCLs) were obtained from hospital controls, left hemisphere lesion Ss, right hemisphere lesion Ss, and diffuse or bilateral lesion Ss during several experimental conditions involving rest, passive auditory stimulation, motor reactions, and simple “perception”. The unilateral lesion groups generally displayed significantly higher palmar SCLs on the side contralateral to their lesion. Such “laterality” was not demonstrated in dorsal recordings or in the hospital controls or diffuse lesion group. These unilateral lesion groups had higher palmar SCLs during passive stimulation than during rest, motor, or perception phases. Results were discussed in terms of possible neural mechanisms underlying the phenomena. 相似文献
29.
Extraembryonic rhythmic motor activity in higher vertebrates, along with the intrinsic motor activity of the embryo, is important
for the normal development of the embryo. This can have different natures in different classes of amniotes (i.e., motor activities
of the amnion, yolk sac, and uterus), but these have similar functional importance. This activity changes reproducibly during
the process of embryogenesis, providing the optimum conditions for normal embryo development. During embryogenesis, a system
for controlling extraembryonic rhythmic motor activity is also formed. There is a trend for the regulation of this activity
to become more complex in mammals as compared with birds. Reptiles have received little study from this point of view. In
addition to regular changes in extraembryonic rhythmic motor activity during embryogenesis which depend on the developmental
stage of the embryo, motor activity can also change in response to changes in a number of environmental factors (for example,
temperature and the gas composition of the air). This demonstrates the possible involvement of embryo-associated extraembryonic
motor activity in adapting the embryo to changing environmental conditions and maintaining homeostasis for the development
of the embryo itself.
Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 84, No. 10, pp. 961–968, October, 1998. 相似文献
30.
Horii A Smith PF Darlington CL 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2001,140(2):252-200
Spontaneous recovery from the oculomotor and postural symptoms of unilateral labyrinthectomy (UL) is known as vestibular
compensation, which is a useful model for investigation of the mechanisms of lesion-induced CNS plasticity. In the present
study, to elucidate the molecular biological basis of vestibular compensation, we investigated changes in the mRNA expression
of glutamate receptor subunit/subtypes in the rat central vestibular system, including the vestibular nucleus complex (VNC),
inferior olive (IO), and cerebellar flocculus following UL, using a real-time quantitative polymerase chain reaction (PCR)
method. In normal control animals, regional differences in the expression of several glutamate receptor subunit/subtypes,
e.g., NR1 and NR2A subunits of the N-methyl-D-aspartic acid (NMDA) receptor, GluR2 and KA2 subtypes of non-NMDA receptors, and mGluR1 and mGluR7 metabotropic glutamate
receptors, were consistent with previous results from studies using in situ hybridization histochemistry, suggesting that
the real-time quantitative PCR method was a reliable procedure for evaluation of changes in mRNA expression. In the vestibular
nucleus complex, NR2A, GluR2 and mGluR7 mRNA were ipsilaterally downregulated by 6 h following UL (P<0.05, P<0.05 and P<0.01, respectively). In the inferior olive, no changes in gene expression were observed. In the ipsilateral flocculus, KA2
mRNA expression was increased by 50 h post-UL (P<0.05). However, in the contralateral flocculus, mGluR1 mRNA was downregulated by 6 h post-UL (P<0.005). Both the increase in KA2 mRNA expression in the ipsilateral flocculus and the decrease in mGluR1 mRNA expression
in the contralateral flocculus may have had the effect of reducing Purkinje cell inhibition of ipsilateral VNC neurons, thereby
contributing to the rebalancing of spontaneous resting activity between the ipsilateral and contralateral VNCs. It is suggested
that such changes in the activities of the floccular-VNC pathways may be important to the vestibular compensation process.
Electronic Publication 相似文献