11,414 research outputs found

    Synthesis, characterization of a new carbonylated zirconium metallocene using a dichloro-zirconocene derived from partially alkylated s-indacene

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    Indexación: ScieloThis work describes the synthesis and characterization of new organometallic species, an unprecedented mononuclear zirconium complex bearing a tetraalkylated s-indacene ligand, and secondly, its respective dicarbonyl complex obtained by reduction with Mg/HgCl2. Theoretical calculations of these two compounds were carried out to gain further understanding of these novel molecular systems.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072009000300014&lng=es&nrm=is

    Characterization of a putative grapevine Zn transporter, VvZIP3, suggests its involvement in early reproductive development in Vitis vinifera L

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    Gonzalez, E (reprint author), Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, Chile.Background: Zinc (Zn) deficiency is one of the most widespread mineral nutritional problems that affect normal development in plants. Because Zn cannot passively diffuse across cell membranes, it must be transported into intracellular compartments for all biological processes where Zn is required. Several members of the Zinc-regulated transporters, Iron-regulated transporter-like Protein (ZIP) gene family have been characterized in plants, and have shown to be involved in metal uptake and transport. This study describes the first putative Zn transporter in grapevine. Unravelling its function may explain an important symptom of Zn deficiency in grapevines, which is the production of clusters with fewer and usually smaller berries than normal. Results: We identified and characterized a putative Zn transporter from berries of Vitis vinifera L., named VvZIP3. Compared to other members of the ZIP family identified in the Vitis vinifera L. genome, VvZIP3 is mainly expressed in reproductive tissue - specifically in developing flowers - which correlates with the high Zn accumulation in these organs. Contrary to this, the low expression of VvZIP3 in parthenocarpic berries shows a relationship with the lower Zn accumulation in this tissue than in normal seeded berries where its expression is induced by Zn. The predicted protein sequence indicates strong similarity with several members of the ZIP family from Arabidopsis thaliana and other species. Moreover, VvZIP3 complemented the growth defect of a yeast Zn-uptake mutant, ZHY3, and is localized in the plasma membrane of plant cells, suggesting that VvZIP3 has the function of a Zn uptake transporter. Conclusions: Our results suggest that VvZIP3 encodes a putative plasma membrane Zn transporter protein member of the ZIP gene family that might play a role in Zn uptake and distribution during the early reproductive development in Vitis vinifera L., indicating that the availability of this micronutrient may be relevant for reproductive development

    Thermodynamics of Higher Spin Black Holes in AdS3_3

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    We discuss the thermodynamics of recently constructed three-dimensional higher spin black holes in SL(N,R)\times SL(N,R) Chern-Simons theory with generalized asymptotically-anti-de Sitter boundary conditions. From a holographic perspective, these bulk theories are dual to two-dimensional CFTs with W_N symmetry algebras, and the black hole solutions are dual to thermal states with higher spin chemical potentials and charges turned on. Because the notion of horizon area is not gauge-invariant in the higher spin theory, the traditional approaches to the computation of black hole entropy must be reconsidered. One possibility, explored in the recent literature, involves demanding the existence of a partition function in the CFT, and consistency with the first law of thermodynamics. This approach is not free from ambiguities, however, and in particular different definitions of energy result in different expressions for the entropy. In the present work we show that there are natural definitions of the thermodynamically conjugate variables that follow from careful examination of the variational principle, and moreover agree with those obtained via canonical methods. Building on this intuition, we derive general expressions for the higher spin black hole entropy and free energy which are written entirely in terms of the Chern-Simons connections, and are valid for both static and rotating solutions. We compare our results to other proposals in the literature, and provide a new and efficient way to determine the generalization of the Cardy formula to a situation with higher spin charges.Comment: 30 pages, PDFLaTeX; v2: typos corrected, explicit expressions for the free energy adde

    Rapid Phenotype-Driven Gene Sequencing with the NeoSeq Panel: A Diagnostic Tool for Critically Ill Newborns with Suspected Genetic Disease

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    New genomic sequencing techniques have shown considerable promise in the field of neonatology, increasing the diagnostic rate and reducing time to diagnosis. However, several obstacles have hindered the incorporation of this technology into routine clinical practice. We prospectively evaluated the diagnostic rate and diagnostic turnaround time achieved in newborns with suspected genetic diseases using a rapid phenotype-driven gene panel (NeoSeq) containing 1870 genes implicated in congenital malformations and neurological and metabolic disorders of early onset (<2 months of age). Of the 33 newborns recruited, a genomic diagnosis was established for 13 (39.4%) patients (median diagnostic turnaround time, 7.5 days), resulting in clinical management changes in 10 (76.9%) patients. An analysis of 12 previous prospective massive sequencing studies (whole genome (WGS), whole exome (WES), and clinical exome (CES) sequencing) in newborns admitted to neonatal intensive care units (NICUs) with suspected genetic disorders revealed a comparable median diagnostic rate (37.2%), but a higher median diagnostic turnaround time (22.3 days) than that obtained with NeoSeq. Our phenotype-driven gene panel, which is specific for genetic diseases in critically ill newborns is an affordable alternative to WGS and WES that offers comparable diagnostic efficacy, supporting its implementation as a first-tier genetic test in NICUs

    Grain Boundary Chemistry Before and After Ion Implantation in ODS Steels

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    Aplicação de indicadores clínicos de exposição na avaliação da saúde da agricultura familiar: o caso de Sumaré, Brasil.

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    Esse texto trata da avaliação da metodologia que emprega indicadores clínicos como parâmetros da exposição de agricultores a agrotóxicos durante o seu uso na agricultura, valendo-se de uma proposta interdisciplinar e que almeja, em última análise, subsidiar os sistemas de produção que buscam a sustentabilidade. A área do estudo foi o Assentamento Rural I de Sumaré, SP, composto por 26 famílias de agricultores, que produz basicamente olerícolas, com destaque para o cultivo do tomate. A metodologia constou de quatro etapas consecutivas, que incluíam o diagnóstico da situação da saúde dos moradores da área, dos seus métodos de aplicação de agrotóxicos e dos princípios ativos mais utilizados, a avaliação de parâmetros clínicos como bioindicadores e a discussão em conjunto com os agricultores e seus familiares a respeito das ações de desenvolvimento na área. A metodologia empregada mostrou-se promissora na avaliação inicial da saúde de populações agrícolas do segmento familiar, sem implicar em custos excessivos

    Primary malignant melanoma of the biliary tract: A case report and literature review

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    BACKGROUND: Primary malignant melanoma of the biliary tract (MBT) is a rare condition whose diagnosis requires excluding a primary origin in another location. This paper reviews the most important characteristics of MBT cases published in the literature and reports a new case. The patient reported here is the first case of primary malignant melanoma of the biliary tract with pulmonary metastasis treated with immunotherapy. This patient remains disease-free 36 mo after the treatment of metastatic lung lesions. CASE SUMMARY: A 51-year-old man was admitted to the gastrointestinal department to study obstructive jaundice of a 1 wk clinical course. Magnetic resonance cholangiopancreatography revealed dilatation of the intrahepatic biliary tract and stenosis of the common hepatic duct. Given the suspicion of biliary tract neoplasia, cholecystectomy and resection of the common hepatic duct were performed with hepatic jejunostomy free of complications. Anatomo-pathological diagnosis was melanoma. After intervention, the patient was referred to the Department of Medical Oncology, where a primary origin was excluded in the skin, mucosa, and eyes. This confirmed diagnosis of primary biliary tract melanoma. Computed tomography was performed 12 mo after the procedure revealed several subcentimetric lung nodules. Wedge resection was performed. After confirming the diagnosis of pulmonary metastasis of primary melanoma of the biliary tract, the patient was started on immunotherapy with nivolumab. Tolerance to treatment was excellent. The patient remains disease-free 36 mo after the treatment of metastatic lung lesions. CONCLUSION: The patient reported here is the first case of primary malignant melanoma of the biliary tract with lung metastases successfully treated with immunotherapy

    First complete Providencia rettgeri genome sequence, the NDM-1-producing clinical strain RB151

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    © 2017 Marquez-Ortiz et al. Providencia rettgeri is an opportunistic bacterial pathogen of clinical significance due to its association with urinary tract infections and multidrug resistance. Here, we report the first complete genome sequence of P. rettgeri. The genome of strain RB151 consists of a 4.8-Mbp chromosome and a 108-kbp blaNDM-1-positive plasmid

    DNA methylation biomarkers of myocardial infarction and cardiovascular disease

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    Background: The epigenetic landscape underlying cardiovascular disease (CVD) is not completely understood and the clinical value of the identifed biomarkers is still limited. We aimed to identify diferentially methylated loci associ‑ ated with acute myocardial infarction (AMI) and assess their validity as predictive and causal biomarkers. Results: We designed a case-control, two-stage, epigenome-wide association study on AMI (ndiscovery=391, nvalidation=204). DNA methylation was assessed using the Infnium MethylationEPIC BeadChip. We performed a fxed efects meta-analysis of the two samples. 34 CpGs were associated with AMI. Only 12 of them were available in two independent cohort studies (n~1800 and n~2500) with incident coronary and cardiovascular disease (CHD and CVD, respectively). The Infnium HumanMethylation450 BeadChip was used in those two studies. Four of the 12 CpGs were validated in association with incident CHD: AHRR-mapping cg05575921, PTCD2-mapping cg25769469, intergenic cg21566642 and MPO-mapping cg04988978. We then assessed whether methylation risk scores based on those CpGs improved the predictive capacity of the Framingham risk function, but they did not. Finally, we aimed to study the causality of those associations using a Mendelian randomization approach but only one of the CpGs had a genetic infuence and therefore the results were not conclusive. Conclusions: We have identifed 34 CpGs related to AMI. These loci highlight the relevance of smoking, lipid metab‑ olism, and infammation in the biological mechanisms related to AMI. Four were additionally associated with incident CHD and CVD but did not provide additional predictive informatio
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