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51.
纳特竖蟾(无尾目:滑背蟾科) 的细胞遗传、与相关属物种的核型相似性并兼论其分类地位 总被引:1,自引:0,他引:1
本文报道纳特竖蟾(Eupemphix nattereri Steindachner,1863)巴西3个产地标本的核型,均为2n=22,由1对端部和10对中或亚中部着丝点染色体组成.仅一对NORs位于No.11染色体对长臂端部,而其位置有别于常见的具有标志性意义的近着丝点位置.该NORs的位置为rDNA为探针的荧光原位杂交(FISH)所确认.各染色体对中,着丝点C-带明显,插入或端带偶见.某些标本的No.8同源染色体对间C-带的大小随异染色质化的程度不同而变化.居于较小的实验标本量,这种在3个产地的雌或雄性标本之一中观察到的C-带异型现象可能为种下细胞地理学变异,亦或为细胞学意义的性染体分化.3产地之一的标本核型的No.11着丝点C-带异染色质化的程度较高.CMA3染色检测到部分GC-rich区域,DAPI染色未显示任何AT-rich区.成功获得BrdU复制带,并将其与滑背蟾类动物(leiuperid)中近缘属及物种进行对比分析.比较结果表明,纳特竖蟾的核型与斑符泡蟾种组(Physalaemus signifer group)难以相互区别,而与肿肋蟾属(Pleurodema Tschudi,1838)极为相似.核型数据支持形态学上将纳特竖蟾、二光肿肋蟾[Pleurodema diplolister (Peters,1870)]和短头肿肋蟾[P.brachyops(Cope,1869)]划为同一分支的观点[动物学报 53(2):285-293,2007]. 相似文献
52.
Zampieri D Mamolo MG Vio L Banfi E Scialino G Fermeglia M Ferrone M Pricl S 《Bioorganic & medicinal chemistry》2007,15(23):7444-7458
New bis-imidazole derivatives have been synthesized and their antifungal and antimycobacterial activity was determined. Almost all compounds exhibited a moderate to good activity against two clinical isolates of Candida albicans 3038 and Candida glabrata 123. The same compounds showed an interesting killing activity against Mycobacterium tuberculosis H(37)Rv reference strain. Docking procedures combined with molecular dynamics simulations in the MM/PBSA framework of theory were applied to predict the binding mode of all compounds in the binding pocket of the cytochrome P450 14alpha-sterol demethylase (14DM) of C. albicans, for which no ligand-protein crystal structure is currently available. The results obtained in silico showed that the active compounds may interact at the active site of protein, and that their binding free energy values are in agreement with the corresponding experimental activity values. 相似文献
53.
The p75 neurotrophin receptor (p75(NTR)), a member of the tumor necrosis factor superfamily of receptors, undergoes multiple proteolytic cleavage events. These events are initiated by an alpha-secretase-mediated release of the extracellular domain followed by a gamma-secretase-mediated intramembrane cleavage. However, the specific determinants of p75(NTR) cleavage events are unknown. Many other substrates of gamma-secretase cleavage have been identified, including Notch, amyloid precursor protein, and ErbB4, indicating there is broad substrate recognition by gamma-secretase. Using a series of deletion mutations and chimeric receptors of p75(NTR) and the related Fas receptor, we have identified domains that are essential for p75(NTR) proteolysis. The initial alpha-secretase cleavage was extracellular to the transmembrane domain. Unfortunately, deletion mutants were not capable of defining the requirements of ectodomain shedding. Although this cleavage is promiscuous with respect to amino acid sequence, its position with respect to the transmembrane domain is invariant. The generation of chimeric receptors exchanging different domains of noncleavable Fas receptor with p75(NTR), however, revealed that a discrete domain above the membrane is sufficient for efficient cleavage of p75(NTR). Mass spectrometric analysis confirmed the cleavage can occur with a truncated p75(NTR) displaying only 15 extracellular amino acids in the stalk region. 相似文献
54.
Age‐dependent expression of DNMT1 and DNMT3B in PBMCs from a large European population enrolled in the MARK‐AGE study 下载免费PDF全文
Fabio Ciccarone Marco Malavolta Roberta Calabrese Tiziana Guastafierro Maria Giulia Bacalini Anna Reale Claudio Franceschi Miriam Capri Antti Hervonen Mikko Hurme Beatrix Grubeck‐Loebenstein Bernhard Koller Jürgen Bernhardt Christiane Schn P. Eline Slagboom Olivier Toussaint Ewa Sikora Efstathios S. Gonos Nicolle Breusing Tilman Grune Eugne Jansen Martijn Doll María Moreno‐Villanueva Thilo Sindlinger Alexander Bürkle Michele Zampieri Paola Caiafa 《Aging cell》2016,15(4):755-765
55.
Stefania Zampieri Ezio Bianchi Carlo Cantile Roberta Saleri Bruno Bembi Andrea Dardis 《PloS one》2014,9(11)
Niemann-Pick C disease (NPC) is an autosomal recessive lysosomal storage disorder characterized by accumulation of unesterified cholesterol and other lipids within the lysosomes due to mutation in NPC1 or NPC2 genes. A feline model of NPC carrying a mutation in NPC1 gene has been previously described. We have identified two kittens affected by NPC disease due to a mutation in NPC2 gene. They manifested with tremors at the age of 3 months, which progressed to dystonia and severe ataxia. At 6 months of age cat 2 was unable to stand without assistance and had bilaterally reduced menace response. It died at the age of 10 months. Post-mortem histological analysis of the brain showed the presence of neurons with cytoplasmic swelling and vacuoles, gliosis of the substantia nigra and degeneration of the white matter. Spheroids with accumulation of ubiquitinated aggregates were prominent in the cerebellar cortex. Purkinje cells were markedly reduced in number and they showed prominent intracytoplasmic storage. Scattered perivascular aggregates of lymphocytes and microglial cells proliferation were present in the thalamus and midbrain. Proliferation of Bergmann glia was also observed. In the liver, hepatocytes were swollen because of accumulation of small vacuoles and foamy Kupffer cells were also detected. Foamy macrophages were observed within the pulmonary interstitium and alveoli as well. At 9 months cat 1 was unable to walk, developed seizures and it was euthanized at 21 months. Filipin staining of cultured fibroblasts showed massive storage of unesterified cholesterol. Molecular analysis of NPC1 and NPC2 genes showed the presence of a homozygous intronic mutation (c.82+5G>A) in the NPC2 gene. The subsequent analysis of the mRNA showed that the mutation causes the retention of 105 bp in the mature mRNA, which leads to the in frame insertion of 35 amino acids between residues 28 and 29 of NPC2 protein (p.G28_S29ins35). 相似文献
56.
Zampieri S Montalvo A Blanco M Zanin I Amartino H Vlahovicek K Szlago M Schenone A Pittis G Bembi B Dardis A 《Gene》2012,499(2):262-265
Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the deficient activity of hexosaminidase A due to mutations in the HEXA gene. Up to date there is no information regarding the molecular genetics of TSD in Argentinean patients. In the present study we have studied 17 Argentinean families affected by TSD, including 20 patients with the acute infantile form and 3 with the sub-acute form. Overall, we identified 14 different mutations accounting for 100% of the studied alleles. Eight mutations were novel: 5 were single base changes leading to drastic residue changes or truncated proteins, 2 were small deletions and one was an intronic mutation that may cause a splicing defect. Although the spectrum of mutations was highly heterogeneous, a high frequency of the c.459+5G>A mutation, previously described in different populations was found among the studied cohort. Haplotype analysis suggested that in these families the c.459+5G>A mutation might have arisen by a single mutational event. 相似文献
57.
Eduardo AVF Ramalho Jo?o LQ Silva-Filho Marina FS Cartaxo Carmelita BL Cavalcanti Moacyr JBM Rêgo Maria BM Oliveira Eduardo IC Beltr?o 《Biological research》2014,47(1)
Background
BRCA protein interacts with at least 13 different proteins that have been implicated with cancer susceptibility and loss of BRCA function is correlated to sensitivity to DNA crosslinking agents in preclinical models.Results
BRCA2 methylation frequency was 44%, p53 Pro22 allele frequency was 32% and heterozygous frequency of Arg/Pro72 genotype was 60% which could be associated as risk factor for metastasis (p = 0.046 OR = 4.190). Regarding to polymorphism of codon 249 the frequency of Arg249 allele presented 82% which was considered not statistically significant.Conclusions
There was not statistical significance to BRCA2 promoter methylation with any parameters chosen. However, our findings suggest that patients who present heterozygous genotype at codon 72 of p53 gene may have a major susceptibility to any type of metastasis and this could serve as potential auxiliary biomarker for poor prognosis. 相似文献58.
Bruna Lancia Zampieri Joice Matos Biselli-Périco Jorge Estefano Santana de Souza Matheus Carvalho Bürger Wilson Araújo Silva Júnior Eny Maria Goloni-Bertollo érika Cristina Pavarino 《PloS one》2014,9(9)
Individuals with Down syndrome (DS) have a high incidence of immunological alterations with increased susceptibility to bacterial and viral infections and high frequency of different types of hematologic malignancies and autoimmune disorders. In the current study, we profiled the expression pattern of 92 immune-related genes in peripheral blood mononuclear cells (PBMCs) of two different groups, children with DS and control children, to identify differentially expressed genes that might be of pathogenetic importance for the development and phenotype of the immunological alterations observed in individuals with DS. PBMCs samples were obtained from six DS individuals with karyotypically confirmed full trisomy 21 and six healthy control individuals (ages 2–6 years). Gene expression was profiled in duplicate according to the manufacturer''s instructions provided by commercially available TaqMan Human Immune Array representing 92 immune function genes and four reference genes on a 96-plex gene card. A set of 17 differentially expressed genes, not located on chromosome 21 (HSA21), involved in immune and inflammatory pathways was identified including 13 genes (BCL2, CCL3, CCR7, CD19, CD28, CD40, CD40LG, CD80, EDN1, IKBKB, IL6, NOS2 and SKI) significantly down-regulated and four genes (BCL2L1, CCR2, CCR5 and IL10) significantly up-regulated in children with DS. These findings highlight a list of candidate genes for further investigation into the molecular mechanism underlying DS pathology and reinforce the secondary effects of the presence of a third copy of HSA21. 相似文献
59.
R. M. Thomas A. Zampieri K. Jumel S. E. Harding 《European biophysics journal : EBJ》1997,25(5-6):405-410
Alpha-helical coiled coils are proving to be almost ideal systems for the modelling of peptide and protein self-association
processes. Stable oligomeric systems, in which the stoichiometry is well defined, can be produced by the careful selection
of the appropriate amino acid sequence, although the principles behind this are still not fully understood. Here we report
on a 35 residue peptide, FZ, synthesized by the solid phase method, which was originally designed to form a dimer, but which,
in fact, associates to the trimeric state. A detailed characterization of the associative properties of the peptide has been
performed by circular dichroism spectroscopy and, in particular, by sedimentation equilibrium in the analytical ultracentrifuge.
The presence of the trimeric state, which is stable even at low peptide concentrations, has been confirmed by various, independent
methods of analysis for molar mass. The effects of both temperature and of guanidinium chloride on the peptide have been investigated
and both found to be peptide-concentration dependent. The unfolding induced by the denaturant cannot be adequately described
by a simple, two state monomer-trimer equilibrium.
Received: 29 November 1996 / Accepted: 2 December 1996 相似文献
60.
AbstractAlthough the New Zealand ground wētā (Anostostomatidae: Hemiandrus) are widespread and abundant, little has been described of their ecology and behaviour. Within the genus several lineages have evolved with ovipositors that are unusually short for this orthopteran family. Some species with this derived morphological character also exhibit maternal care of eggs and offspring. Two new species are described here, Hemiandrus maia sp. nov. and Hemiandrus electra sp. nov. Although morphologically similar with medium length ovipositors, they are not sister taxa and live at opposite ends of South Island, New Zealand. The behaviour of Hemiandrus maia sp. nov. was studied using burrow door re-construction as a key to activity patterns. Observations at night and burrow excavation during the day were used to identify features of their behaviour. Maternal care of both eggs and nymphs was observed. Hemiandrus maia sp. nov. were shown to eat fruit, invertebrates and seeds without discrimination.http://zoobank.org/urn:lsid:zoobank.org:pub:1C7EB0D2-D01B-4D3A-B643-D17813EC2084 相似文献