1,096 research outputs found

    The Pathobiology of Neisseria gonorrhoeae Lower Female Genital Tract Infection

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    Infection and disease associated with Neisseria gonorrhoeae, the gonococcus, continue to be a global health problem. Asymptomatic and subclinical gonococcal infections occur at a high frequency in females; thus, the true incidence of N. gonorrhoeae infections are presumed to be severely underestimated. Inherent to this asymptomatic/subclinical diseased state is the continued prevalence of this organism within the general population, as well as the medical, economic, and social burden equated with the observed chronic, disease sequelae. As infections of the lower female genital tract (i.e., the uterine cervix) commonly result in subclinical disease, it follows that the pathobiology of cervical gonorrhea would differ from that observed for other sites of infection. In this regard, the potential responses to infection that are generated by the female reproductive tract mucosa are unique in that they are governed, in part, by cyclic fluctuations in steroid hormone levels. The lower female genital tract has the further distinction of being able to functionally discriminate between resident commensal microbiota and transient pathogens. The expression of functionally active complement receptor 3 by the lower, but not the upper, female genital tract mucosa; together with data indicating that gonococcal adherence to and invasion of primary cervical epithelial cells and tissue are predominately aided by this surface-expressed host molecule; provide one explanation for asymptomatic/subclinical gonococcal cervicitis. However, co-evolution of the gonococcus with its sole human host has endowed this organism with variable survival strategies that not only aid these bacteria in successfully evasion of immune detection and function but also enhance cervical colonization and cellular invasion. To this end, we herein summarize current knowledge pertaining to the pathobiology of gonococcal infection of the human cervix

    Medicaid and CHIP Strategies for Improving Child Health

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    Explains state programs' need for child health measures that focus on outcomes; are standardized across programs, agencies, and states; and reward performance through provider reimbursement. Points out opportunities for foundation and government support

    Silver palladium catalysts for the direct synthesis of hydrogen peroxide

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    A series of bimetallic silver–palladium catalysts supported on titania were prepared by wet impregnation and assessed for the direct synthesis of hydrogen peroxide, and its subsequent side reactions. The addition of silver to a palladium catalyst was found to significantly decrease hydrogen peroxide productivity and hydrogenation, but crucially increase the rate of decomposition. The decomposition product, which is predominantly hydroxyl radicals, can be used to decrease bacterial colonies. The interaction between silver and palladium was characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The results of the TPR and XPS indicated the formation of a silver–palladium alloy. The optimal 1% Ag–4% Pd/TiO 2 bimetallic catalyst was able to produce approximately 200 ppm of H 2 O 2 in 30 min. The findings demonstrate that AgPd/TiO 2 catalysts are active for the synthesis of hydrogen peroxide and its subsequent decomposition to reactive oxygen species. The catalysts are promising for use in wastewater treatment as they combine the disinfectant properties of silver, hydrogen peroxide production and subsequent decomposition. This article is part of a discussion meeting issue ‘Providing sustainable catalytic solutions for a rapidly changing world’.</jats:p

    Loss of signal transducer and activator of transcription 1 is associated with prostate cancer recurrence

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    STAT1 loss has previously been implicated in cell line studies to modify prostate cancer cell growth and survival, however the clinical significance of this has not previously been established. This study investigated if STAT1 loss was associated with patient outcome measures and the phenotypic consequence of STAT1 silencing. STAT1 expression was assessed in two patient cohorts with localised (n = 78) and advanced prostate cancer at initial diagnosis (n = 39) by immunohistochemistry (IHC). Impact of STAT1 silencing on prostate cancer cells lines was assessed using Cell Death detection ELISA, TLDA gene signature apoptosis arrays, WST-1 assay, xCELLigence system, clonogenic assay, and wound healing assay. In the localised patient cohort, low expression of STAT1 was associated with shorter time to disease recurrence (3.8 vs 7.3 years, P = 0.02) and disease specific survival (6.6 vs 9.3 years, P = 0.05). In the advanced patient cohort, low expression was associated with shorter time to disease recurrence (2.0 vs 3.9 years, P = 0.001). When STAT1 was silenced in PC3 cells (AR negative) and LNCaP cells (AR positive) silencing did not influence levels of apoptosis in either cell line and had little effect on cell viability in the LNCaP cells. In contrast, STAT1 silencing in the PC3 cells resulted in a pronounced increase in cell viability (WST-1 assay: mock silenced vs STAT1 silenced, P &lt; 0.001), clonagenicity (clonogenic assay: mock silenced vs STAT1 silenced, P &lt; 0.001), and migration (wound healing: mock silenced vs STAT1 silenced, P &lt; 0.001). In conclusion, loss of STAT1 may promote prostate cancer recurrence in AR negative patients via increasing cell viability

    Bicatalytic Multistep Reactions En Route to the One-Pot Total Synthesis of Complex Molecules: Easy Access to Chromene and 1,2-Dihydroquinoline Derivatives from Simple Substrates

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    By combining nanocatalysis and base-catalysis, a novel one-pot multistep process was found for the synthesis of substituted heterocycles of biological relevance from simple substrates. It is based on an initial Au/O2 oxidation of allylic alcohols followed by a base-catalysed tandem hetero-Michael/aldolisation/crotonisation with ortho-hydroxy or ortho-amino benzaldehydes. The flexibility of the reaction even allowed the benzaldehyde partner to be prepared in situ in an example of one-pot/5-steps process

    The direct synthesis of hydrogen peroxide from H<sub>2</sub> and O<sub>2</sub> using Pd-Ni/TiO<sub>2</sub> catalysts

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    The direct synthesis of hydrogen peroxide (H2O2) from molecular H2 and O2 offers an attractive solution to decentralised production compared to the anthraquinone process. Herein we evaluate the performance of a 0.5%Pd-4.5%Ni/TiO2 catalyst in batch and flow reactor systems using water as a solvent at ambient temperature which makes synthesising high H2O2 concentrations challenging. Catalyst activity was observed to be stable to prolonged use in multiple batch experiments or in a flow system, with selectivities towards H2O2 of 97% and 85% respectively. This study was carried out in the absence of halide or acid additives that are typically used to inhibit sequential H2O2 degradation reactions showing that this Pd-Ni catalyst has potential to produce H2O2 selectivel

    Neuroprotection by minocycline in murine traumatic spinal cord injury: analyses of matrix metalloproteinases

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    Aim: Minocycline has neuroprotective activities in several models of neurological disorders including spinal cord injury (SCI) where it prevents axonal loss and improves functional recovery. There are still gaps of knowledge on minocycline in SCI including whether it ameliorates neuronal loss at the focal site of trauma, and whether minocycline reduces the activity of matrix metalloproteinases (MMPs), a family of enzymes implicated in the pathophysiology of SCI. This study addressed these gaps. Methods: Mice were treated with either minocycline or vehicle control after a spinal cord contusion. MMPs were compared between the two groups using real time polymerase chain reaction and zymography. Immunohistochemistry was used to examine microglial activation and neuronal cell death. Results: While several MMP members were elevated in the spinal cord following injury, treatment with minocycline did not affect their expression. Importantly, minocycline reduced the loss of neurons in the epicenter of damage to the spinal cord and in segments caudal and rostral to the injury. Conclusion: Despite the inability of minocycline to alter MMPs, the results of neuroprotection at the lesion site support the continued testing of minocycline as a neuroprotective medication in experimental and clinical SCI

    Rapid microwave-assisted polyol synthesis of TiO2-supported ruthenium catalysts for levulinic acid hydrogenation

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    One wt% Ru/TiO2 catalysts prepared by a one-pot microwave-assisted polyol method have been shown to be highly active for Levulinic acid hydrogenation to γ-Valerolactone. Preparation temperature, microwave irradiation time and choice of Ru precursor were found to have a significant effect on catalyst activity. In the case of Ru(acac)3-derived catalysts, increasing temperature and longer irradiation times increased catalyst activity to a maximum LA conversion of 69%. Conversely, for catalysts prepared using RuCl3, shorter preparation times and lower temperatures yielded more active catalysts, with a maximum LA conversion of 67%. Catalysts prepared using either precursor were found to contain highly dispersed nanoparticles <3 nm in diameter. XPS analysis of the most and least active catalysts shows that the catalyst surface is covered in a layer of insoluble carbon with surface concentrations exceeding 40% in some cases. This can be attributed to the formation of large condensation oligomers from the reaction between the solvent, ethylene glycol and its oxidation products, as evidenced by the presence of C-O and C = O functionality on the catalyst surfac

    Population and hierarchy of active species in gold iron oxide catalysts for carbon monoxide oxidation

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    The identity of active species in supported gold catalysts for low temperature carbon monoxide oxidation remains an unsettled debate. With large amounts of experimental evidence supporting theories of either gold nanoparticles or sub-nm gold species being active, it was recently proposed that a size-dependent activity hierarchy should exist. Here we study the diverging catalytic behaviours after heat treatment of Au/FeOx materials prepared via co-precipitation and deposition precipitation methods. After ruling out any support effects, the gold particle size distributions in different catalysts are quantitatively studied using aberration corrected scanning transmission electron microscopy (STEM). A counting protocol is developed to reveal the true particle size distribution from HAADF-STEM images, which reliably includes all the gold species present. Correlation of the populations of the various gold species present with catalysis results demonstrate that a size-dependent activity hierarchy must exist in the Au/FeOx catalyst

    Solid Acid Additives as Recoverable Promoters for the Direct Synthesis of Hydrogen Peroxide

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    The effectiveness of Cs-exchanged phosphotungstic acid as a recoverable solid acid additive for the direct synthesis of hydrogen peroxide (H2O2) using an Au-Pd / TiO2 catalyst is investigated and compared to the promotion effect of common oxides and non-halo acids. A clear improvement in catalytic activity towards H2O2 synthesis is reported when utilising Cs-containing heteropolyacids in addition to a standard H2O2 synthesising catalyst. The effect of Cs content on the promotion of H2O2 formation is investigated and the feasibility of a reusable heterogeneous additive has been explored revealing that the presence of the acid additive not only stabilises the H2O2 that is produced but also increases the H2O2 synthesis rate
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