2,590 research outputs found

    Electronic and structural properties of rare gas cation clusters

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    We study structure and ground and excited state properties of rare gas cation clusters, Rg+N, for N=3-60. The main goal is to understand how the positive charge is delocalized over the cluster and the relationship between cluster geometry and delocalization. He+N, Ar+N, and Xe+N are selected as representatives of the rare gas elements. We perform Monte Carlo simulations to obtain finite temperature properties of the energy spectrum. The Hamiltonian of the system is based on a semi-empirical model whose parameters are obtained through the fitting of experimental and calculated properties such as bond length and dissociation energy of small clusters (N \u3c 6). Since rare gas cation clusters are formed by closed shell atoms with one electron deficiency, the Hamiltonian is constructed within a hole (electron deficiency) formalism, resulting in a single particle model. In addition, our model can treat polarization and dispersion energies as a many-body interaction which is very important for small clusters. We compare our results with experiments through calculations of photoabsorption cross section and magic numbers

    The histone deacetylase inhibitor JAHA down-regulates pERK and global DNA methylation in MDA-MB231 breast cancer cells

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    The histone deacetylase inhibitor N1-(ferrocenyl)-N8-hydroxyoctanediamide (JAHA) down-regulates extracellular-signal-regulated kinase (ERK) and its activated form in triple-negative MDA-MB231 breast cancer cells after 18 h and up to 30 h of treatment, and to a lesser extent AKT and phospho-AKT after 30 h and up to 48 h of treatment. Also, DNA methyltransferase 1 (DNMT1), 3b and, to a lesser extent, 3a, downstream ERK targets, were down-regulated already at 18 h with an increase up to 48 h of exposure. Methylation-sensitive restriction arbitrarily-primed (MeSAP) polymerase chain reaction (PCR) analysis confirmed the ability of JAHA to induce genome-wide DNA hypomethylation at 48 h of exposure. Collective data suggest that JAHA, by down-regulating phospho-ERK, impairs DNMT1 and 3b expression and ultimately DNA methylation extent, which may be related to its cytotoxic effect on this cancer cytotype

    ITQ-69: A Germanium-Containing Zeolite and its Synthesis, Structure Determination, and Adsorption Properties

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    "This is the peer reviewed version of the following article:ITQ-69: A Germanium-Containing Zeolite and its Synthesis, Structure Determination, and Adsorption Properties, which has been published in final form at https://doi.org/10.1002/anie.202100822. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] In this work, a new zeolite named as ITQ-69, has been synthesized, characterized and its application as selective adsorbent for industrially relevant light olefins/paraffins separations has been assessed. This material has been obtained as pure germania as well as silica-germania zeolites with different Si/Ge ratios using a diquaternary ammonium cation as organic structure directing agent. Its structure was determined by single-crystal X-Ray diffraction showing a triclinic unit cell forming a tridirectional small pore channel system (8x8x8R). Also, it has been found that Si preferentially occupies some special T sites of the structure as deduced from Rietveld analysis of the powder X-ray diffraction patterns. In addition, the new zeolite ITQ-69 has been found to be stable upon calcination and thus, its adsorption properties were evaluated, showing a promising kinetic selectivity for light olefin separations in the C3 fraction.The authors acknowledge the Spanish Ministry of Science, Innovation and Universities (MCIU) for their funding via project RTI2018-101784-B-I00 and Program Severo Ochoa SEV-2016-0683. AS and EPB thanks for their grants BES-2016-078684 and FPU15/01602, respectively. The Microscopy Service of the UPV is acknowledged for their help in sample characterization. By last, authors would like to thank the use of RIAIDT-USC analytical facilities, especially to Dr. Antonio L. Llamas for extremely useful comments on SCXRD analyses.Sala-Gascon, A.; Pérez-Botella, E.; Jorda Moret, JL.; Cantin Sanz, A.; Rey Garcia, F.; Valencia Valencia, S. (2021). ITQ-69: A Germanium-Containing Zeolite and its Synthesis, Structure Determination, and Adsorption Properties. Angewandte Chemie International Edition. 60(21):11745-11750. https://doi.org/10.1002/anie.2021008221174511750602

    Synthesis and study of novel multifunctional cyclodextrin‐deferasirox hybrids

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    Metal dyshomeostasis is central to a number of disorders that result from, inter alia, oxidative stress protein misfolding, and cholesterol dyshomeostasis. In this respect, metal deficiencies are usually readily corrected by treatment with supplements, whereas metal overload can be overcome by the use of metal‐selective chelation therapy. Deferasirox, 4‐[(3Z,5E)‐3,5‐bis(6‐oxo‐1‐cyclohexa‐2,4‐dienylidene)‐1,2,4‐triazolidin‐1‐yl]benzoic acid, Exjade, or ICL670, is used clinically to treat hemosiderosis (iron overload), which often results from multiple blood transfusions. Cyclodextrins are cyclic glucose units that are extensively used in the pharmaceutical industry as formulating agents as well as for encapsulating hydrophobic molecules such as in the treatment of Niemann Pick C or for hypervitaminosis. We have conjugated deferasirox, via an amide coupling reaction, to both 6A‐amino‐6A‐deoxy‐β‐cyclodextrin and 3A‐amino‐3A‐deoxy‐2A(S),3A(R)‐β‐cyclodextrin, at the upper and lower rim respectively creating hybrid molecules with dual properties, capable of both metal chelation and cholesterol encapsulation. Our findings emphasize the importance of the conjugation of β‐cyclodextrin with deferasirox to significantly improve the biological properties and reduce the cytotoxicity of this drug

    A Dual Role for KRT81: A miR-SNP Associated with Recurrence in Non-Small-Cell Lung Cancer and a Novel Marker of Squamous Cell Lung Carcinoma

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    MicroRNAs (miRNAs) play an important role in carcinogenesis through the regulation of their target genes. miRNA-related single nucleotide polymorphisms (miR-SNPs) can affect miRNA biogenesis and target sites and can alter microRNA expression and functions. We examined 11 miR-SNPs, including 5 in microRNA genes, 3 in microRNA binding sites and 3 in microRNA-processing machinery components, and evaluated time to recurrence (TTR) according to miR-SNP genotypes in 175 surgically resected non-small-cell lung cancer (NSCLC) patients. Significant differences in TTR were found according to KRT81 rs3660 (median TTR: 20.3 months for the CC genotype versus 86.8 months for the CG or GG genotype; P = 0.003) and XPO5 rs11077 (median TTR: 24.7 months for the AA genotype versus 73.1 months for the AC or CC genotypes; P = 0.029). Moreover, when patients were divided according to stage, these differences were maintained for stage I patients (P = 0.002 for KRT81 rs3660; P<0.001 for XPO5 rs11077). When patients were divided into sub-groups according to histology, the effect of the KRT81 rs3660 genotype on TTR was significant in patients with squamous cell carcinoma (P = 0.004) but not in those with adenocarcinoma. In the multivariate analyses, the KRT81 rs3660 CC genotype (OR = 1.8; P = 0.023) and the XPO5 rs11077 AA genotype (OR = 1.77; P = 0.026) emerged as independent variables influencing TTR. Immunohistochemical analyses in 80 lung specimens showed that 95% of squamous cell carcinomas were positive for KRT81, compared to only 19% of adenocarcinomas (P<0.0001). In conclusion, miR-SNPs are a novel class of SNPs that can add useful prognostic information on the clinical outcome of resected NSCLC patients and may be a potential key tool for selecting high-risk stage I patients. Moreover, KRT81 has emerged as a promising immunohistochemical marker for the identification of squamous cell lung carcinoma

    Cell encapsulation:Promise and progress

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    In cell encapsulation, transplanted cells are protected from immune rejection by an artificial, semipermeable membrane, potentially allowing transplantation (allo-or xenotransplantation) without the need for immunosuppression. Yet, despite some promising results in animal studies, the field has not lived up to expectations, and clinical products based on encapsulated cell technology continue to elude the scientific community. This commentary discusses the reasons for this, summarizes recent progress in the field and outlines what is needed to bring this technology closer to clinical application

    Results and evaluation of the expansion of a model of comprehensive care for Chagas disease within the National Health System: The Bolivian Chagas network

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    Background: Most people with chronic Chagas disease do not receive specific care and therefore are undiagnosed and do not receive accurate treatment. This manuscript discusses and evaluates a collaborative strategy to improve access to healthcare for patients with Chagas in Bolivia, a country with the highest prevalence of Chagas in the world. Methods: With the aim of reinforcing the Chagas National Programme, the Bolivian Chagas Platform was born in 2009. The first stage of the project was to implement a vertical pilot program in order to introduce and consolidate a consensual protocol-based healthcare, working in seven centers (Chagas Platform Centers). From 2015 on the model was extended to 52 primary healthcare centers, through decentralized, horizontal scaling-up. To evaluate the strategy, we have used the WHO ExpandNet program. Results: The strategy has significantly increased the number of patients cared for, with 181,397 people at risk of having T. cruzi infection tested and 57,871 (31·9%) new diagnostics performed. In those with treatment criteria, 79·2% completed the treatment. The program has also trained a significant number of health personnel through the specific Chagas guidelines (67% of healthcare workers in the intervention area). Conclusions: After being recognized by the Chagas National Programme as a healthcare model aligned with national laws and priorities, the Bolivian platform of Chagas as an innovation, includes attributes that they have made it possible to expand the strategy at the national level and could also be adapted in other countries

    Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort

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    Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2, 445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionizationtime of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD
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