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排序方式: 共有5659条查询结果,搜索用时 31 毫秒
21.
山莨菪碱对家兔动脉粥样硬化的抑制作用 总被引:1,自引:0,他引:1
用65只日本兔喂高脂饲料,观察山莨菪碱对动脉粥样硬化形成的作用及其有关检测指标的影响。结果表明,山莨菪碱组主动脉内膜粥样硬化斑块面积、胆固醇含量、内膜通透性及血液TC、LDL-C、TG、LPO、TXA_2、5-HT、Pt聚集力,血液流变学等,均显著降低;PGI_2及SOD增高;组织光镜及电镜改变减轻。说明山茛菪碱对动脉粥样硬化的形成有显著抑制作用。 相似文献
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Liu JQ; Bai XF; Shi FD; Xiao BG; Li HL; Levi M; Mustafa M; Wahren B; Link H 《International immunology》1998,10(8):1139-1148
Induction of mucosal tolerance by inhalation of soluble peptides with
defined T cell epitopes is receiving much attention as a means of
specifically down-regulating pathogenic T cell reactivities in autoimmune
and allergic disorders. Experimental autoimmune encephalomyelitis (EAE)
induced in the Lewis rat by immunization with myelin basic protein (MBP)
and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the
MBP amino acid sequences 68-86 and 87-99. To further define the principles
of nasal tolerance induction, we generated three different MBP peptides
(MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and
evaluated whether their nasal administration on day -11, -10, -9, -8 and -7
prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection
to Lewis rat EAE. Protection was achieved with the encephalitogenic
peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP
110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete
protection to gp-MBP-induced EAE. In contrast, nasal administration of a
mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even
at lower dosage compared to that being used for individual peptides. Rats
tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses
to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays.
Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive
IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node
cells compared to rats receiving MBP 110-128 nasally, while similar low
levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA
expressing cells were observed in the two groups. Nasal administration of
MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord
homogenate-induced EAE, and passive transfer of spleen mononuclear cells
from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE.
Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse
ongoing EAE induced with gp-MBP, although higher doses are required
compared to the dosage needed for prevention. In conclusion, nasal
administration of encephalitogenic MBP peptides can induce antigen-specific
T cell tolerance and confer incomplete protection to gp-MBP-induced EAE,
and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms
are proposed to be responsible for tolerance development after nasal
peptide administration.
相似文献
24.
胎儿消化器官发育中的肥大细胞超微结构特点 总被引:3,自引:0,他引:3
实验对10例不同胎龄肥儿消化器官的胎大细胞进行了超微结构观察,发现胎儿发育接近成熟时,其肥大细胞根据颗粒的超微结构可分TC肥大细胞和T肥大细胞两型;胎儿发育后期以大细胞有分泌活动呈活化状态;胎儿肥大细胞与成纤维细胞,上皮细胞,血管,神经等密切接触。 相似文献
25.
Abnormal protein aggregation is emerging as a common theme in the pathogenesis of neurodegenerative disease. Our previous studies have shown that overexpression of untranslated light neurofilament (NF-L) RNA causes motor neuron degeneration in transgenic mice, leads to accumulation of ubiquitinated aggregates in degenerating cultured motor neurons and triggers aggregation of NF-L protein and co-aggregation of mutant SOD1 protein in neuronal cells. Here, we report that p190RhoGEF, an RNA-binding protein that binds to a destabilizing element in NF-L mRNA, is involved in aggregation of NF-L protein and is implicated in the pathogenesis of motor neuron degeneration. We show that p190RhoGEF co-aggregates with unassembled NF-L protein and that co-aggregation is associated with down-regulation of parent NF-L mRNA in neuronal cells. Co-expression of NF-M increases NF assembly and reduces RNA-triggered aggregation as well as loss of solubility of NF-L protein. siRNA-induced down-regulation of p190RhoGEF not only reduces aggregation and promotes assembly of NF-L and NF-M, but also causes reversal of aggregation and recovery of NF assembly in transfected cells. Examination of transgenic models of motor neuron disease shows that prominent aggregates of p190RhoGEF and NF-L and down-regulation of NF-L expression occur in degenerating motor neurons of mice expressing untranslated NF-L RNA or a G93A mutant SOD1 transgene. Moreover, aggregates of p190RhoGEF and NF-L appear as early pathological changes in presymptomatic G93A mutant SOD1 transgenic mice. Together, the findings indicate that p190RhoGEF is involved in aggregation of NF-L protein and support a working hypothesis that aggregation of p190RhoGEF and NF-L is an upstream event triggering neurotoxicity in motor neuron disease. 相似文献
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肾细胞癌中抑癌基因PTEN的表达及生物学意义 总被引:2,自引:3,他引:2
目的 :研究抑癌基因PTEN在肾细胞癌的表达及其生物学意义。方法 :应用免疫组织化学S P法检测 5例正常肾组织、18例癌旁肾组织和 40例肾细胞癌组织中抑癌基因PTEN的表达。结果 :5例正常肾组织和 18例癌旁肾组织均有较强的PTEN蛋白的表达 ,二者PTEN蛋白的表达强度、阳性细胞的分布形式无差异。抑癌基因PTEN在肾细胞癌中的表达不同于正常肾组织和癌旁肾组织 ,12 5 %的肾细胞癌呈PTEN蛋白阴性 ;17 5 %的肾细胞癌PTEN蛋白呈弱阳性 ;70 %的肾细胞癌PTEN蛋白呈阳性或强阳性 ,与癌旁组织PTEN蛋白的染色强度无差异。PTEN蛋白阴性的肾细胞癌 ,肾门淋巴结转移率为80 % ;PTEN蛋白阳性的肾细胞癌 ,肾门淋巴结转移率为 2 0 %。PTEN蛋白阴性肾细胞癌的肾门淋巴结转移率与PTEN阳性肾细胞癌的肾门淋巴结转移率比较 ,差异有显著性 (P <0 0 5 )。结论 :肾细胞癌中存在着抑癌基因PTEN的表达缺失和异常 ;抑癌基因PTEN的表达异常可能与肾细胞癌的发生、发展有关 ,抑癌基因PTEN是肾细胞癌的一种新的相关基因。 相似文献
28.
NF-κB在人肝细胞肝癌中的表达及与HBV X蛋白的关系 总被引:2,自引:0,他引:2
目的:研究核转录因子NF--κB在人肝细胞肝癌组织中的表达及其与乙型肝炎病毒(HBV )X蛋白的关系。方法;用免疫组织化学S-P法,检测52例人肝细胞肝癌组织中核转录因子NF--κB及HBV X蛋白的表达;用脂质体介导的基因转染法将HBV x基因真核表达载体pcDNA3.1-HBX转染入人肝癌细胞系HCC-9204,检测肝癌细胞内核转录因子NF--κB的表达。结果:52例人肝细胞肝癌组织均有核转录因子NF--κB的广泛表达,并且在11例HBV X蛋白阳性的肝癌组织,核转录因子NF--κB位于细胞胞质和胞核,而在41例HBV X蛋白阴性的肝癌组织,核转录因子NF--κB位于肝癌细胞的胞质。将HBV x基因真核表达载体pcDNA3.1-HBX转染 入人肝癌细胞系HCC-9204,并在稳定表达X蛋白 的肝癌细胞,核转录因子NF--κB定位于其胞质和胞核,而未进行基因转染的亲体细胞,核转录因子NF--κB仅定位于细胞质,细胞核无核转录因子NF--κB的表达。结论:核转录因子NF--κB在人肝细胞肝癌组织中广泛表达,人肝细胞肝癌中存在着核转录因子NF--κB的异常激活,并且核转录因子NF--κB的异常激活与HBV X蛋白有关,X蛋白激活核转录因子NF--κB, 使其从细胞转位于细胞核,这可能在HBV相关的人原发性肝癌肝癌的发生中起一定作用。 相似文献
29.
30.
Chen M Bennedsen M Zhai L Kharazmi A 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2001,109(12):801-808
A 65 kD membrane-associated NADH-fumarate reductase subunit, which has a molecular weight similar to that of one of the enzyme subunits from bacteria, was purified from Leishmania donovani promastigotes. NADH-fumarate reductase and other mitochondrial enzymatic activities of L. major and L. donovani promastigotes and amastigotes were investigated. The presence of NADH-fumarate reductase was demonstrated in digitonin-permeabilized L. major promastigotes and mitochondria of L. major and L. donovani promastigotes and amastigotes. The activity of solubilized NADH-fumarate reductase was measured in L. major and L. donovani promastigotes. Succinate exhibited a clear concentration-dependent inhibitory effect on fumarate reductase, whereas fumarate also exhibited a clear concentration-dependent inhibitory effect on succinate dehydrogenase. The data indicate that fumarate reductase is an obligatory component of the respiratory chain of the parasite. Since the enzyme is an important component in the intermediate metabolism in the Leishmania parasite and is absent in mammalian cells, it could be a potential target for antileishmanial drugs. 相似文献