76. Profile and spectrum of congenital heart defect in pediatric patient with down syndrome

Down syndrome is one of the most common chromosomal abnormality worldwide. It occurs in 1 of every 800 live births. Almost one-half of patients with Down Syndrome have congenital heart defect. Our objective is to describe the frequency and spectrum of congenital heart defect (CHD) among children with Down Syndrome in Saudi Arabia and identify the rate of primary and secondary pulmonary hypertension among pediatric patients with Down syndrome. Cross-sectional, retrospective study of the cardiac anomalies among 331 pediatric patients (0–18 years) with Down Syndrome in King Khalid University Hospital (KKUH) from August 2001 till October 2014. The demographic data, reason for referral, echocardiography data including systolic function parameters, the presence of CHD, type and details of CHD, presence of pulmonary hypertension (PHTN), history of cardiac surgeries or transcatheter interventions. Among the 331 pediatric patients with Down Syndrome; 230 patients (69.5%) have Congenital Heart Defect (CHD). The patients with CHD were significantly younger (median age 3 months) with lower weight (P-value <0.05) and height (P-value <0.05) compared to patients with no CHD. The median age at first assessment was 3 months. The most common type of CHDs among DS pediatric patients was atrial septal defect secundum (ASD II) which account for 33.5% of all CHD followed by ventricular septal defect (VSD) which account for 26.5%, then atrioventricular septal defect (AVSD) 21.7% and moderate to large patent ductus arteriosus (PDA) 21.7%. There is another (11.7%) who have other CHDs. Pulmonary hypertension was present in 32% of patients with CHD vs 4% among patients with no CHD. There is significant relationship between CHD and pulmonary hypertension with odds ratio 11.3 (CI 3.99–31.83, P-value <0.05). 15% of patients underwent either cardiac surgery or transcatheter intervention. Almost two thirds of Down Syndrome patients have CHD with pulmonary hypertension affecting almost one third of patients with CHD. The most common CHD among Down Syndrome patients were ASD, VSD, AVSD and moderate to large PDA. Early detection is required to facilitate early management and prevent complications manage patients and preform early interventions as appropriate

Metal Oxides as Catalyst/Supporter for CO₂ Capture and Conversion, Review

Various carbon dioxide (CO2) capture materials and processes have been developed in recent years. The absorption-based capturing process is the most significant among other processes, which is widely recognized because of its effectiveness. CO2 can be used as a feedstock for the production of valuable chemicals, which will assist in alleviating the issues caused by excessive CO2 levels in the atmosphere. However, the interaction of carbon dioxide with other substances is laborious because carbon dioxide is dynamically relatively stable. Therefore, there is a need to develop types of catalysts that can break the bond in CO2 and thus be used as feedstock to produce materials of economic value. Metal oxide-based processes that convert carbon dioxide into other compounds have recently attracted attention. Metal oxides play a pivotal role in CO2 hydrogenation, as they provide additional advantages, such as selectivity and energy efficiency. This review provides an overview of the types of metal oxides and their use for carbon dioxide adsorption and conversion applications, allowing researchers to take advantage of this information in order to develop new catalysts or methods for preparing catalysts to obtain materials of economic value

A multi-criteria assessment of climate change impacts on urban sustainability in Dammam Metropolitan Area, Saudi Arabia

Climate change (CC) is increasingly causing precarious and pervasive disruption to lives, livelihoods, and the environment. The Global South countries are vulnerable to CC impacts due to rapid urbanization, poverty, low resilience, and poor governance. While some countries have implemented measures to mitigate CC impacts, many strive to do so. Saudi Arabia is among the Global South countries with high per capita energy use and carbon emission. However, there is a dearth of studies that assess the impacts of CC for better mitigation efforts and decision-making. The present study is an effort to attend to this research need. This article uses experts-based survey (n = 12) to assess the impacts of CC on the Dammam Metropolitan Area using an Analytic Hierarchy Process (AHP). The findings indicate that the highest ranked CC impacts based on priority weights are sea-level rise then coastal flooding, trailed by the threat to public health and low agricultural productivity. However, groundwater depletion and urban heat islands were deemed having the least impacts. Also, the experts ranked green infrastructure and sustainable transportation as more effective than green buildings in mitigating CC impacts in the study area. The study recommends that green infrastructure (GI), sustainable transportation (ST), and sustainable urban form (SUF) are more appropriate mitigation measures to CC impacts in Saudi Arabia and similar geographical regions. Because CC impacts on humans and the environment are widespread, mitigation and adaptation efforts can assist in lowering their adverse effects and promoting environmental sustainability

The importance of inner cavity space within Ni@SiO2 nanocapsule catalysts for excellent coking resistance in the high-space-velocity dry reforming of methane

Metal sintering and carbon deposition are acknowledged to be the foremost critical issues in the important energy storage process of high temperature Dry Reforming of Methane (DRM). For that process, so-called “core-shell catalysts” have exhibited outstanding catalytic performance. However, the intrinsic confined geometric space of the host core-shell structure not only inevitably limits the ability of the catalyst system to facilitate the critical rapid infusion and diffusion of reacting gases, but also enhances the accompanying conversion of carbon intermediates to inert, catalyst-deactivating carbonaceous deposits under high-space-velocity conditions. Herein, we present a study highlighting the importance of the inner cavity space, now of a quasi-zero-dimensional, tubular, yolk-shell structured Ni@SiO2 nanocapsule catalyst, in the DRM process. The tubular yolk-shell structured Ni@SiO2 nanocapsule catalysts having controlled inner cavities (5.0–13.0 nm × 5.0–50.0 nm dimensions) were synthesised via a water-in-oil micro-emulsion method by employing different aging times (i.e. 3 h, 6 h and 12 h). Compared with corresponding Ni@SiO2 nanosphere catalysts, the tubular nanocapsule catalysts displayed both excellent catalyst activity, stability, and (metal) anti-sintering ability with, equally important, negligible carbon deposition during the operating DRM process under high space velocity conditions (60 L g−1 h−1), most relevant for application in real industrial processes

Fuels, power and chemical periodicity

The insatiable—and ever-growing—demand of both the developed and the developing countries for power continues to be met largely by the carbonaceous fuels comprising coal, and the hydrocarbons natural gas and liquid petroleum. We review the properties of the chemical elements, overlaid with trends in the periodic table, which can help explain the historical—and present—dominance of hydrocarbons as fuels for power generation. However, the continued use of hydrocarbons as fuel/power sources to meet our economic and social needs is now recognized as a major driver of dangerous global environmental changes, including climate change, acid deposition, urban smog and the release of many toxic materials. This has resulted in an unprecedented interest in and focus on alternative, renewable or sustainable energy sources. A major area of interest to emerge is in hydrogen energy as a sustainable vector for our future energy needs. In that vision, the issue of hydrogen storage is now a key challenge in support of hydrogen-fuelled transportation using fuel cells. The chemistry of hydrogen is itself beautifully diverse through a variety of different types of chemical interactions and bonds forming compounds with most other elements in the periodic table. In terms of their hydrogen storage and production properties, we outline various relationships among hydride compounds and materials of the chemical elements to provide some qualitative and quantitative insights. These encompass thermodynamic and polarizing strength properties to provide such background information. We provide an overview of the fundamental nature of hydrides particularly in relation to the key operating parameters of hydrogen gravimetric storage density and the desorption/operating temperature at which the requisite amount of hydrogen is released for use in the fuel cell. While we await the global transition to a completely renewable and sustainable future, it is also necessary to seek CO2 mitigation technologies applied to the use of fossil fuels. We review recent advances in the strategy of using hydrocarbon fossil fuels themselves as compounds for the high capacity storage and production of hydrogen without any CO2 emissions. Based on these advances, the world may end up with a hydrogen economy completely different from the one it had expected to develop; remarkably, with ‘Green hydrogen' being derived directly from the hydrogen-stripping of fossil fuels. This article is part of the theme issue ‘Mendeleev and the periodic table'

Clinical and histologic evaluation of different approaches to gain keratinized tissue prior to implant placement in fully edentulous patients

OBJECTIVES: This work aimed to investigate the effectiveness and predictability of different treatment modalities for gain of keratinized tissue (KT) in fully edentulous jaws prior to dental implant placement: apically positioned flap (APF), APF plus xenogeneic collagen matrix (XCM), and APF plus free gingival graft (FGG). MATERIALS AND METHODS: In fully edentulous patients with insufficient zones of KT at the prospective implant positions, four treatment modalities were performed in the lower jaw: APF, XCM, FGG, and an untreated control group (control). APF and XCM were applied in the first molar positions, FGG and control in the canine positions. Assessed outcomes up to 3 months post-surgery included changes in width of KT (over a 3-month period), histomorphometric analysis of harvested soft-tissue biopsies (at 3 months postoperatively), and patient-reported outcomes measures (PROMs). RESULTS: For the primary outcome, changes in KT width demonstrated an increase of 1.93 ± 1.6 mm (APF), whereas XCM and FGG showed an increase of 4.63 ± 1.25 mm and 3.64 ± 2.01, respectively. Histomorphometric analyses revealed a thickness of the epithelium ranging between 375 ± 122 μm (APF), 410 ± 116 μm (XCM), 336 ± 122 μm (FGG), and 413 ± 109 μm (control). All biopsies showed a regular muco-periosteal structure with a keratinized epithelium of comparable thickness in all groups. CONCLUSION: All three methods were suitable to increase the width of KT, although APF alone rendered roughly 50% less gain compared to XCM and FGG. CLINICAL RELEVANCE: The use of XCM in conjunction with an APF represents a valuable treatment option for the gain of keratinized tissue in edentulous sites

Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South

Solid waste management (SWM) is one of the key responsibilities of city administrators and one of the effective proxies for good governance. Effective SWM mitigates adverse health and environmental impacts, conserves resources, and improves the livability of cities. However, unsustainable SWM practices, exacerbated by rapid urbanization and financial and institutional limitations, negatively impact public health and environmental sustainability. This review article assesses the human and environmental health impacts of SWM practices in the Global South cities that are the future of global urbanization. The study employs desktop research methodology based on in-depth analysis of secondary data and literature, including official documents and published articles. It finds that the commonplace SWM practices include mixing household and commercial garbage with hazardous waste during storage and handling. While waste storage is largely in old or poorly managed facilities such as storage containers, the transportation system is often deficient and informal. The disposal methods are predominantly via uncontrolled dumping, open-air incinerators, and landfills. The negative impacts of such practices include air and water pollution, land degradation, emissions of methane and hazardous leachate, and climate change. These impacts impose significant environmental and public health costs on residents with marginalized social groups mostly affected. The paper concludes with recommendations for mitigating the public and environmental health risks associated with the existing SWM practices in the Global South

3D Covalent Organic Frameworks of Interlocking 1D Square Ribbons.

A new mode of mechanical entanglement in extended structures is described where 1D organic ribbons of corner-sharing squares are mutually interlocked to form 3D woven covalent organic framework-500, COF-500. Reaction of aldehyde-functionalized tetrahedral Cu(PDB)2PO2Ph2 complexes (PDB = 4,4'-(1,10-phenanthroline-2,9-diyl)dibenzaldehyde) with rectangular tetratopic ETTBA (4',4‴,4''''',4''''‴-(ethene-1,1,2,2-tetrayl)tetrakis([1,1'-biphenyl]-4-amine)) linkers through imine condensation, yielded a crystalline porous metalated COF, COF-500-Cu, with pts topology. Upon removal of the Cu(I) ions, the individual 1D square ribbons in the demetalated form (COF-500) are held together only by mechanical interlocking of rings, which allows their collective movement to produce a narrow-pore form, as evidenced by nitrogen adsorption and solid-state photoluminescence studies. When exposed to tetrahydrofuran vapor, the interlocking ribbons can dynamically move away from each other to reopen up the structure. The structural integrity of COF-500 is maintained during its dynamics because the constituent square ribbons cannot part company due to spatial confinement imparted by their interlocking nature