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71.
The preparation and crystal structure of a decametallic MnII carboxylate cluster containing neutral 2-pyridinealdoxime, (py)C(H)NOH, and its anion, (py)C(H)NO−, is reported. The reaction between Mn(O2CPh)2 · 2H2O and (py)C(H)NOH in CH2Cl2, in the presence of NH4PF6, produces the complex [Mn10(O2CPh)12{(py)C(H)CNO}6{(py)C(H)NOH}2](PF6)2 · 2.6CH2Cl2 · 1.3H2O (1 · 2.6CH2Cl2 · 1.3H2O) in good yield. The cationic complex consists of ten MnII ions assembled together by four η1:η1:η3:μ4 and two η1:η1:η2:μ3 oximato(−1) ligands, and four η1:η2:μ3 ligands to form an unprecedented core, where R = PhCO and R′ = (py)C(H)N. Peripheral ligation is provided by a combination of bridging benzoates and chelating (py)C(H)NOH ligands. Dc magnetic susceptibility studies reveal the presence of dominant antiferromagnetic interactions leading to a spin ground-state of ST = 0. A survey of the ternary reaction system is attempted with comparisons to previously reported complexes. 相似文献
72.
de Brouwer AP Williams KL Duley JA van Kuilenburg AB Nabuurs SB Egmont-Petersen M Lugtenberg D Zoetekouw L Banning MJ Roeffen M Hamel BC Weaving L Ouvrier RA Donald JA Wevers RA Christodoulou J van Bokhoven H 《American journal of human genetics》2007,81(3):507-518
Arts syndrome is an X-linked disorder characterized by mental retardation, early-onset hypotonia, ataxia, delayed motor development, hearing impairment, and optic atrophy. Linkage analysis in a Dutch family and an Australian family suggested that the candidate gene maps to Xq22.1-q24. Oligonucleotide microarray expression profiling of fibroblasts from two probands of the Dutch family revealed reduced expression levels of the phosphoribosyl pyrophosphate synthetase 1 gene (PRPS1). Subsequent sequencing of PRPS1 led to the identification of two different missense mutations, c.455T-->C (p.L152P) in the Dutch family and c.398A-->C (p.Q133P) in the Australian family. Both mutations result in a loss of phosphoribosyl pyrophosphate synthetase 1 activity, as was shown in silico by molecular modeling and was shown in vitro by phosphoribosyl pyrophosphate synthetase activity assays in erythrocytes and fibroblasts from patients. This is in contrast to the gain-of-function mutations in PRPS1 that were identified previously in PRPS-related gout. The loss-of-function mutations of PRPS1 likely result in impaired purine biosynthesis, which is supported by the undetectable hypoxanthine in urine and the reduced uric acid levels in serum from patients. To replenish low levels of purines, treatment with S-adenosylmethionine theoretically could have therapeutic efficacy, and a clinical trial involving the two affected Australian brothers is currently underway. 相似文献
73.
Kountouris P Agathocleous M Promponas VJ Christodoulou G Hadjicostas S Vassiliades V Christodoulou C 《IEEE/ACM transactions on computational biology and bioinformatics / IEEE, ACM》2012,9(3):731-739
Filtering of Protein Secondary Structure Prediction (PSSP) aims to provide physicochemically realistic results, while it usually improves the predictive performance. We performed a comparative study on this challenging problem, utilizing both machine learning techniques and empirical rules and we found that combinations of the two lead to the highest improvement. 相似文献
74.
Fotini Giannakopoulou Dionisios Gasparatos Constantina Haidouti Ioannis Massas 《Soil & Sediment Contamination》2012,21(8):937-950
The characteristics of Cs sorption behavior in two soils (soil 1 and soil 2) with nearly the same clay content and exhangeable K concentration, but with different clay mineralogy, were studied by the quantification of the distribution coefficient (kd). It was observed that as the initial Cs concentration increased from 4 to 50 mg L?1, the kd values decreased in both soils, suggesting a progressive saturation of Cs available sorption sites. However, the presence of expansible 2:1 phyllosilicates minerals in the clay fraction of soil 2 maintained a high Cs sorption ability for this soil, even at high Cs concentrations. The experimental data were also fitted to the Freundlich isotherm and the results showed that parameters of the Freundlich equation could be used to estimate the degree of Cs sorption and the nature of the available sorption sites. For the studied soils, the kf and the kd values followed a similar trend and the n Freundlich constant values provided a reliable indicator for the soils’ clay mineralogy. The removal of the sand fraction enhanced Cs sorption in both soils and the absence of sorbed Cs ions on the quartz minerals, as observed by the SEM analysis, additionally supported the effect of particle-size fraction on Cs sorption. 相似文献
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KA Nicolaou V Liapis A Evdokiou C Constantinou P Magiatis AL Skaltsounis L Koumas PA Costeas AI Constantinou 《Biochemical and biophysical research communications》2012,425(1):76-82
Indirubin derivatives gained interest in recent years for their anticancer and antimetastatic properties. The objective of the present study was to evaluate and compare the anticancer properties of the two novel bromo-substituted derivatives 6-bromoindirubin-3'-oxime (6BIO) and 7-bromoindirubin-3'-oxime (7BIO) in five different breast cancer cell lines. Cell viability assays identified that 6BIO and 7BIO are most effective in preventing the proliferation of the MDA-MB-231-TXSA breast cancer cell line from a total of five breast cancer cell lined examined. In addition it was found that the two compounds induce apoptosis via different mechanisms. 6BIO induces caspase-dependent programmed cell death through the intrinsic (mitochondrial) caspase-9 pathway. 7BIO up-regulates p21 and promotes G(2)/M cell cycle arrest which is subsequently followed by the activation of two different apoptotic pathways: (a) a pathway that involves the upregulation of DR4/DR5 and activation of caspase-8 and (b) a caspase independent pathway. In conclusion, this study provides important insights regarding the molecular pathways leading to cell cycle arrest and apoptosis by two indirubin derivatives that can find clinical applications in targeted cancer therapeutics. 相似文献
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79.
Spiridon Kaloudis Constantina I. Costopoulou Nikos A. Lorentzos Alexander B. Sideridis Michael Karteris 《Ecological Informatics》2008,3(1):122-133
Forest management planning is generally a complicated task. The amount of data, information and knowledge involved in the management process is often overwhelming. Decision support systems can help forest managers make well documented decisions concerning forest management planning. These systems include a wide variety of components, depending on the management goals of the forested land. Although an increased growth of decision support systems in specific domains of forest management planning exists, there is no special design model for the deployment of forest management planning. To this direction, this paper has the following objectives: Firstly, to propose a conceptual design model for developing goal-driven forest management planning decision support systems. Secondly, to apply the design model for a particular case of these systems, the wildfire risk reduction decision support systems. Thirdly, to present the deployment of a wildfire risk reduction decision support system as well as its results for a specific forest area. 相似文献
80.
Tremoleda JL Forsyth NR Khan NS Wojtacha D Christodoulou I Tye BJ Racey SN Collishaw S Sottile V Thomson AJ Simpson AH Noble BS McWhir J 《Cloning and stem cells》2008,10(1):119-132
Although the use of embryonic stem cells in the assisted repair of musculoskeletal tissues holds promise, a direct comparison of this cell source with adult marrow-derived stem cells has not been undertaken. Here we have compared the osteogenic differentiation potential of human embryonic stem cells (hESC) with human adult-derived stem cells in vivo. hESC lines H7, H9, the HEF-1 mesenchymal-like, telomerized H1 derivative, the human embryonic kidney epithelial cell line HEK293 (negative control), and adult human mesenchymal stem cells (hMSC) were either used untreated or treated with osteogenic factors for 4 days prior to injection into diffusion chambers and implantation into nude mice. After 11 weeks in vivo chambers were removed, frozen, and analyzed for evidence of bone, cartilage, and adipose tissue formation. All hESCs, when pretreated with osteogenic (OS) factors gave rise exclusively to bone in the chambers. In contrast, untreated hESCs (H9) formed both bone and cartilage in vivo. Untreated hMSCs did not give rise to bone, cartilage, or adipose tissue in vivo, while pretreatment with OS factors engendered both bone and adipose tissue. These data demonstrate that hESCs exposed to OS factors in vitro undergo directed differentiation toward the osteogenic lineage in vivo in a similar fashion to that produced by hMSCs. These findings support the potential future use of hESC-derived cells in regenerative medicine applications. 相似文献