227 research outputs found

    Formation of high surface area Li/MgO - Efficient catalyst for the oxidative dehydrogenation/cracking of propane.

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    In this study nanoscale clusters of Li/MgO oxide with varying lithium contents are prepared via the sol–gel method. The preparation routine consists of co-gelation of LiNO3 and Mg(OCH3)2 in methanol/water solution followed by drying at 50 °C under vacuum and calcination at 500 °C in air. The structural and textural transformations that take place during oxide formation are studied with TGA–DSC–MS and FTIR spectroscopy. The obtained materials are characterized by TEM, N2 physisorption and XRD. Presence of increasing amounts of lithium precursor causes extensive hydrolysis of the alkoxide sol. Appreciable amounts of lithium ions can be incorporated in the magnesia gel even under the mild conditions during sol–gel transformation. Non-incorporated lithium ions form a separate carbonate phase, which has a detrimental effect on the surface area due to enhanced sintering. The Li/MgO oxide materials thus prepared possess high surface area (50–190 m2/g) depending on Li content. Small amounts of lithium ions, when present as a dispersed phase, do not seem to influence the structural and textural characteristics of the magnesia gel and, in these cases, nanoscale Li/MgO oxide clusters with high surface areas similar to pure MgO can be prepared. Sol–gel derived Li/MgO provides significantly higher olefin yields in ODH of propane in comparison with conventional Li/MgO catalysts, especially at lower temperatures

    A new mouse model to explore therapies for preeclampsia

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    BACKGROUND: Pre-eclampsia, a pregnancy-specific multisystemic disorder is a leading cause of maternal and perinatal mortality and morbidity. This syndrome has been known to medical science since ancient times. However, despite considerable research, the cause/s of preeclampsia remain unclear, and there is no effective treatment. Development of an animal model that recapitulates this complex pregnancy-related disorder may help to expand our understanding and may hold great potential for the design and implementation of effective treatment. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that the CBA/J x DBA/2 mouse model of recurrent miscarriage is also a model of immunologically-mediated preeclampsia (PE). DBA/J mated CBA/J females spontaneously develop many features of human PE (primigravidity, albuminuria, endotheliosis, increased sensitivity to angiotensin II and increased plasma leptin levels) that correlates with bad pregnancy outcomes. We previously reported that antagonism of vascular endothelial growth factor (VEGF) signaling by soluble VEGF receptor 1 (sFlt-1) is involved in placental and fetal injury in CBA/J x DBA/2 mice. Using this animal model that recapitulates many of the features of preeclampsia in women, we found that pravastatin restores angiogenic balance, ameliorates glomerular injury, diminishes hypersensitivity to angiotensin II and protects pregnancies. CONCLUSIONS/SIGNIFICANCE: We described a new mouse model of PE, were the relevant key features of human preeclampsia develop spontaneously. The CBA/J x DBA/2 model, that recapitulates this complex disorder, helped us identify pravastatin as a candidate therapy to prevent preeclampsia and its related complications. We recognize that these studies were conducted in mice and that clinical trials are needed to confirm its application to humans

    An integrated genomic analysis of lung cancer reveals loss of DUSP4 in EGFR-mutant tumors.

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    To address the biological heterogeneity of lung cancer, we studied 199 lung adenocarcinomas by integrating genome-wide data on copy number alterations and gene expression with full annotation for major known somatic mutations in this cancer. This showed non-random patterns of copy number alterations significantly linked to EGFR and KRAS mutation status and to distinct clinical outcomes, and led to the discovery of a striking association of EGFR mutations with underexpression of DUSP4, a gene within a broad region of frequent single-copy loss on 8p. DUSP4 is involved in negative feedback control of EGFR signaling, and we provide functional validation for its role as a growth suppressor in EGFR-mutant lung adenocarcinoma. DUSP4 loss also associates with p16/CDKN2A deletion and defines a distinct clinical subset of lung cancer patients. Another novel observation is that of a reciprocal relationship between EGFR and LKB1 mutations. These results highlight the power of integrated genomics to identify candidate driver genes within recurrent broad regions of copy number alteration and to delineate distinct oncogenetic pathways in genetically complex common epithelial cancers

    Dual inhibition of histone deacetylases and phosphoinositide 3-kinase enhances therapeutic activity against B cell lymphoma

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    Phosphoinositide 3-kinase (PI3K) and Myc are known to cooperate in promoting the survival and growth of a variety of B-cell lymphomas. While currently there are no small molecule inhibitors of Myc protein, histone deacetylase (HDAC) inhibitors have been shown to reduce levels of Myc protein by suppressing its transcription. We assessed the efficacy of CUDC-907, a new rationally designed dual inhibitor of PI3K and HDACs, in a panel of lymphoma cell lines. CUDC-907 treatment resulted in a dose- and time-dependent growth inhibition and cell death of DLBCL cell lines, irrespective of the cell of origin. CUDC-907 treatment down-regulated the phosphorylation of PI3K downstream targets, including AKT, PRAS40, S6, and 4EBP1, increased histone 3 acetylation, and decreased Myc protein levels. SILAC-based quantitative mass spectrometry demonstrated that CUDC-907 treatment decreased the protein levels of several components of the B cell receptor (BCR) and Toll like receptor (TLR) pathways, including BTK, SYK, and MyD88 proteins. These cellular changes were associated with an inhibition of NF-kB activation. CUDC-907 demonstrated in vivo efficacy with no significant toxicity in a human DLBCL xenograft mouse model. Collectively, these data provide a mechanistic rationale for evaluating CUDC-907 for the treatment of patients with Myc and PI3K-dependent lymphomas

    Normal reference values of strength in pelvic floor muscle of women: a descriptive and inferential study

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    Background: To describe the clinical, functional and quality of life characteristics in women with Stress Urinary Incontinence (SUI). In addition, to analyse the relationship between the variables reported by the patients and those informed by the clinicians, and the relationship between instrumented variables and the manual pelvic floor strength assessment.Methods: Two hundred and eighteen women participated in this observational, analytical study. An interview about Urinary Incontinence and the quality of life questionnaires (EuroQoL-5D and SF-12) were developed as outcomes reported by the patients. Manual muscle testing and perineometry as outcomes informed by the clinician were assessed. Descriptive and correlation analysis were carried out.Results: The average age of the subjects was (39.93 ± 12.27 years), (24.49 ± 3.54 BMI). The strength evaluated by manual testing of the right levator ani muscles was 7.79 ± 2.88, the strength of left levator ani muscles was 7.51 ± 2.91 and the strength assessed with the perineometer was 7.64 ± 2.55. A positive correlation was found between manual muscle testing and perineometry of the pelvic floor muscles (p < .001). No correlation was found between outcomes of quality of life reported by the patients and outcomes of functional capacity informed by the physiotherapist.Conclusion: A stratification of the strength of pelvic floor muscles in a normal distribution of a large sample of women with SUI was done, which provided the clinic with a baseline. There is a relationship between the strength of the pelvic muscles assessed manually and that obtained by a perineometer in women with SUI. There was no relationship between these values of strength and quality of life perceived

    Assessment of trace metal contamination in a historical freshwater canal (Buckingham Canal), Chennai, India

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    The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (Igeo) class 4– 6), whereas NBC sediments are enriched in Sn, Cu,Zn, and Hg (Igeo class 4–6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metalsfound in these sediments. The calculated Igeo, Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai MetropolitanCity have negatively influenced on the surrounding aquatic ecosystem
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