Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports

Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/Al_S.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/Al_S.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/Al_S.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.     

Long-stay patients in pediatric intensive care units: Five-years, 2-points,cross-sectional study

Objectives:To explore the changing patterns of long-stay patients (LSP) to improve the utilization of pediatric intensive care units (PICUs) resources.Methods:This is a 2-points cross-sectional study (5 years apart; 2014-2019) conducted among PICUs and SCICUs in Riyadh, Saudi Arabia. Children who have stayed in PICU for more than 21 days were included.Results:Out of the 11 units approached, 10 (90%) agreed to participate. The prevalence of LSP in all these hospitals decreased from 32% (48/150) in 2014 to 23.4% (35/149) in 2019. The length of stay ranged from 22 days to 13.5 years. The majority of LSP had a neuromuscular or cardiac disease and were admitted with respiratory compromise. Ventilator-associated pneumonia was the most prevalent complication (37.5%). The most commonly used resources were mechanical ventilation (93.8%), antibiotics (60.4%), and blood-products transfusions (35.4%). The most common reason for the extended stay was medical reasons (51.1%), followed by a lack of family resources (26.5%) or lack of referral to long-term care facilities (22.4%).Conclusion:A long-stay is associated with significant critical care bed occupancy, complications, and utilization of resources that could be otherwise utilized as surge capacity for critical care services. Decreasing occupancy in this multicenter study deserves further engagement of the healthcare leaders and families to maximize the utilization of resources.     

Pulmonary effects of occupational exposure to Portland cement: a study from eastern Saudi Arabia

A cross-sectional study was conducted in a randomly selected factory producing Portland cement in eastern Saudi Arabia to determine the prevalence of respiratory symptoms and diseases and chest x-ray changes consistent with pneumoconiosis in the employees. A sample of 150 exposed and 355 unexposed employees was selected. A questionnaire about respiratory symptoms was completed during an interview. Chest x-rays were read according to the ILO criteria for pneumoconiosis. Dust level was determined by the gravimetric method. Concentrations of personal respirable dust ranged from 2.13 mg/m3 in the kilns to 59.52 mg/m3 in the quarry area. Cough and phlegm were found to be related to cigarette smoking, while wheezing, shortness of breath, and bronchial asthma were related to dust levels. It is recommended that engineering measures be adopted to reduce the dust level in this company, together with health monitoring of exposed employees.     

Extensive abdominal lymphangiomatosis involving the small bowel mesentery: A case report

BACKGROUNDAbdominal lymphangiomatosis is a rare benign condition accounting for less than 1% of all the cases of lymphangiomatosis. Management usually involves radical surgical excision; however, depending upon the extent of involvement, patient condition, and absence of complications, conservative management can be also considered.CASE SUMMARYWe present the case of a 32-year-old male who presented with short onset abdominal pain and melena. Physical examination findings were within normal limits, except for left lower abdominal tenderness. Upper gastrointestinal endoscopy was within normal limits. Abdominal and pelvic ultrasound and computed tomography (CT) scan revealed numerous, variably-sized cystic lesions within the abdominal cavity, exclusively and extensively affecting the small bowel mesentery with sparing of the retroperitoneum. The diagnosis was confirmed by CT and cytological examination. Radical surgical excision was technically impossible in this patient because of the extensive involvement of the mesentery; therefore, the patient was managed conservatively. CONCLUSIONExtensive and exclusive small bowel mesentery involvement in abdominal lymphangiomatosis is rare. Imaging modalities play an important role in establishing the diagnosis and conservative management can be considered when surgery is technically impossible.     

Hypokalemic periodic paralysis due to CACNA1S gene mutation

Hypokalemic periodic paralysis (HypoPP) is a relatively rare but treatable disorder caused by mutations in the CACNA1S gene. HypoPP patients may experience paralytic episodes associated with hypokalemia and, infrequently, may develop late-onset proximal myopathy. The paralytic attacks are characterized by reversible flaccid paralysis and, in most cases, spare the respiratory muscles and heart. We report a case of CACNA1S periodic paralysis precipitated by vigorous exercise in a 14-year-old boy who presented with sudden-onset paralysis of both his upper and lower extremities. Laboratory evaluation revealed a markedly low serum potassium level. The patient’s symptoms resolved after correction of the potassium abnormality, and he was discharged with no neurological deficits. Although rare, HypoPP must be differentiated from other causes of weakness and paralysis so that proper treatment can be promptly initiated to ensure good outcomes.

Hypokalemic periodic paralysis (HypoPP) is an inherited disorder caused by autosomal dominant gene mutations characterized by recurrent episodes of hypokalemia and muscle weakness. Symptom onset occurs during the first or second decades of life, with severity varying substantially in terms of the frequency and duration of paralytic attacks. Some patients may experience a single episode in their lifetime; in most cases, however, patients experience repeated crises, which may occur daily, weekly, monthly, or less often.1 HypoPP can be divided into primary and secondary disorders. Two forms of primary HypoPP have been identified: thyrotoxic HypoPP, which is associated with thyrotoxicosis and is more common in adult males, and familial HypoPP, which is a genetic disorder with a lower penetrance in women.1 Although the mechanism underlying the pathogenesis of familial HypoPP is unclear, the condition is associated with mutations in genes encoding subunits of ion channels primarily expressed in striated muscle. These include the voltage-dependent L-type calcium channel subunit alpha 1S (CACNA1S) and the voltage-gated sodium channel type IV alpha subunit (SCN4A).2 During the last decade, a few isolated cases of familial HypoPP have been reported in Saudi Arabia, including thyrotoxic HypoPP in an Asian man3 and another in a Saudi man.4 We present the case of a Saudi teenage boy with HypoPP due to CACNA1S gene mutation.