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Background: To analyze the impact of the International Nosocomial Infection Control Consortium (INICC) Multidimensional Approach (IMA) and use of INICC Surveillance Online System (ISOS) on ventilator-associated pneumonia (VAP) rates in Saudi Arabia from September 2013 to February 2017. Methods: A multicenter, prospective, before–after surveillance study on 14,961 patients in 37 intensive care units (ICUs) of 22 hospitals. During baseline, we performed outcome surveillance of VAP applying the definitions of the CDC/NHSN. During intervention, we implemented the IMA and the ISOS, which included: (1) a bundle of infection prevention practice interventions, (2) education, (3) outcome surveillance, (4) process surveillance, (5) feedback on VAP rates and consequences and (6) performance feedback of process surveillance. Bivariate and multivariate regression analyses were performed using generalized linear mixed models to estimate the effect of intervention. Results: The baseline rate of 7.84 VAPs per 1000 mechanical-ventilator (MV)-days―with 20,927 MV-days and 164 VAPs―, was reduced to 4.74 VAPs per 1000 MV-days―with 118,929 MV-days and 771 VAPs―, accounting for a 39% rate reduction (IDR 0.61; 95% CI 0.5–0.7; P 0.001). Conclusions: Implementing the IMA was associated with significant reductions in VAP rates in ICUs of Saudi Arabia. Keywords: Hospital infection, Healthcare-acquired infection, Hospital-acquired pneumonia, Nosocomial pneumonia, Limited-resource countries, Surveillance

The formation of solid inorganic salts from solutions is of fundamental importance for industrial, geological, and biological processes. Here, we review the literature on the fundamentals of inorganic scaling with the goal of elucidating the underlying phenomena observed during thermal desalination processes, mainly multi-stage flash (MSF). We will focus on one of the most common foulants, CaCO3, recognizing that similar phenomena occur for other salts and that behaviors in mixtures with other salts and organic molecules will impact the real world situation. This review will cover a wide range of dimensions, providing views from molecular level to plant scale. In addition to the mechanism and kinetics of scale formation in MSF, we will also review current strategies to control scaling in MSF and highlight directions for future development.

Introduction and importance Heterotopic mesenteric ossification is a benign bony tissue growth in the mesentery that mostly follows repetitive or severe abdominal injuries leading to reactive bone formation in the mesentery. There are only 73 cases (51 publications) identified in the literature up to the beginning of 2020. Case presentation 45-year-old Saudi male underwent multiple laparotomies to manage complicated appendicitis which ended with a diverting ileostomy and a colostomy as a mucus fistula. After 9 months, the patient was admitted to the General Surgery department in Al-Hada Armed Forces Hospital for an open ileostomy and colostomy reversal surgery where several irregular bone-like tissues of hard consistency and sharp edges with some spindle-shaped structures resembling needles were found in the mesentery of the small intestine and histopathology revealed of trabecular bone fragments confirming the diagnosis. Clinical discussion The majority of cases occur mid to late adulthood with a predilection in the male gender, and usually present with bowel obstruction or an enterocutaneous fistula. Although it has no malignant potential, it may cause severe bowel obstruction that can lead to mortality, it's a rare occurrence and, therefore, is difficult to diagnose among many common abdominal disturbances. Conclusion Here we report a rare case of heterotopic mesenteric ossification, which should be considered as one of the delayed complications of abdominal surgery or trauma. The time range of expecting the presentation of heterotopic mesenteric ossification following major abdominal trauma or surgery should be extended and continuously considered during differential diagnosis., Highlights • One of the delayed complications of abdominal surgery or trauma is Heterotopic mesenteric ossification. • Since 1983 there are only 73 cases of Heterotopic mesenteric ossification published to date. • Preoperative diagnosis of Heterotopic mesenteric ossification should be based mainly on the characteristic radiographic findings without relying on the levels of calcium or alkaline phosphatase. • The only way to reach the definitive diagnosis is through excision and histopathological analysis. • Heterotopic mesenteric ossification has no malignant potential, but it can cause severe bowel obstruction that can lead to mortality in already sick patients.

A novel chaotic model with complex variables and cubic non-linear terms was proposed. The new system is a six dimensional continuous real autonomous chaotic system. The characteristics of this system containing invariance, dissipation, equilibria and their stability, Lyapunov exponents, Lyapunov dimension, bifurcation diagrams and chaotic achievement are studied. Converting and turning the system chaotic behavior to its unstable trivial fixed point via the Lyapunov stability theorem. An approach proposed to analyze the system chaos synchronization. Analytical expressions are derived for control functions. The chaos synchronization results were employed to develop a simple application in secure communication. Numerical effects computed to experiment the control forces scientific expressions gravity and to show the chaos synchronization of a chaotic system. Keywords: Chaotic, Control, Synchronization, Lyapunov stability, Complex

Campylobacter jejuni is a leading cause of foodborne bacterial gastroenteritis in human. Chickens are the reservoir host of C. jejuni, and contaminated chicken meat is an important source of human infection. Therefore, control of C. jejuni in chickens can have direct effect on human health. In this study we tested the passive immunotherapeutic efficacy of the chicken egg-yolk-derived antibodies, in the form of hyperimmunized egg yolk powder (HEYP), against 7 colonization-associated proteins of C. jejuni, namely, CadF (Campylobacter adhesion to fibronectin), FlaA (flagellar proteins), MOMP (major outer membrane protein), FlpA (fibronectin binding protein A), CmeC (Campylobacter multidrug efflux C), Peb1A (Campylobacter putative adhesion), and JlpA (Jejuni lipoprotein A). Three chicken experiments were performed. In each experiment, chickens were treated orally via feed supplemented with 10% (wt/wt) egg yolk powder. In experiment 1, chicken groups were experimentally infected with C. jejuni (10(8) cfu) followed by treatment with 5 HEYP (CadF, FlaA, MOMP, FlpA, CmeC) for 4 d either individually or as a cocktail containing equal parts of each HEYP. In experiment 2, chickens were treated for 21 d with cocktail containing equal parts of 7 HEYP before and after experimental infection with C. jejuni (10(8) cfu). In experiment 3, chickens were treated with feed containing a cocktail of 7 HEYP before and after (prophylaxis), and after (treatment) experimental infection with C. jejuni (10(5) cfu). Intestinal colonization of C. jejuni was monitored by culturing cecal samples from chickens euthanized at the end of each experiment. The results showed that there were no differences in the cecal colonization of C. jejuni between HEYP treated and nontreated control chickens, suggesting that use of HEYP at the dose and the regimens used in the current study is not efficacious in reducing C. jejuni colonization in chickens.

Acute necrotizing encephalopathy is a rare, clinically distinct entity of acute encephalopathy triggered by acute febrile diseases, mostly viral infections. It is postulated to arise from uncontrolled cytokine release during a febrile illness, and is most often seen in East Asia. We describe a rare Saudi patient of acute necrotizing encephalopathy attributable to enterovirus in a 4 years and 6 months old girl. A work-up revealed elevations in serum and cerebrospinal fluid interleukin-6 and tumor necrosis factor-α. The outcome on intravenous pulse methylprednisolone was good. This case is the first, to the best of our knowledge, of acute necrotizing encephalopathy reported from Saudi Arabia with a good outcome despite severe magnetic resonance imaging findings and delay in the steroid treatment.

The main objective of this work is to develop a predictive model for predicting the product quality of vacuum gas oil (VGO) hydrocracking process. Experimental data were obtained using a pilot plant hydrocracking catalytic reactor loaded with the same catalyst type used in a local refinery. Two sets of experimental runs were conducted under various operating conditions. The first one consisted of 18 runs and was used for parameter estimation, while the second set consisted of 29 runs and was used for model validation. Distillation curves of the cracked products were obtained using the simulated distillation (SimDist) test. A distribution model based on probability density function was used to develop the predictive model. The distribution model presents the boiling point as a function of the distilled weight fraction. Model parameters were estimated and related to the specific gravity of the cracked product. Model validation results showed that the proposed model is capable of predicting the distillation curves of the hydrocracked products accurately, especially at high operating severity. Simplicity and accuracy of the developed model makes it suitable for online analysis, to estimate the conversion as well as the product distribution of hydrocracking units in refineries.

Thermodynamic models are used to calculate physical properties of petroleum fluids needed for process design and operation in petroleum related industries. Process simulators used for design and operational purposes are usually equipped with as many as a dozen of such thermodynamic models. The basic input parameters needed for use in these thermodynamic models are critical constants, acentric factor and molecular weight. In this paper, sensitivity of calculated properties from different characterization methods is demonstrated. Most commonly used characterization methods have been reviewed and based on evaluations with experimental data for various fluid mixtures recommendations are made for use of an appropriate model for specific hydrocarbon systems.

Kuwait atmospheric residue (KAR) was hydrodemetallized (HDM) over a commercial Mo/Al2O3 catalyst using a fixed-bed reactor unit. Initial coke deposition on the catalyst vs. time-on-stream (TOS) was studied by solid-state 13C NMR to derive structural information on the initial coke deposited in the first 240 h of TOS. 13C NMR spectral editing (cross-polarization technique in combination with the polarization inversion pulse sequence) was applied to distinguish on the one hand between quaternary and tertiary aromatic carbon and on the other hand between secondary and primary aliphatic carbon. Structural parameters, derived from those NMR measurements in combination with the aromaticity from single pulse excitation 13C NMR and the H/C ratio from elemental analysis, have been used to assemble the hypothetical structure of initial coke. The 1 h coke has nearly the same H/C ratio as the KAR and represents an intermediate between heavy coke generating molecules from KAR and real coke. In the following 12 h, aromatic carbon is accumulated and aromatic rings are dealkylated but the coke is still rich in hydrogen. As the carbon deposition slows down (after 50 h) further aromatic carbon is built-up and aliphatic carbon decreases. After 120 h the hydrogenation activity of the HDM catalyst is still high and prevents the coke from getting hydrogen depleted, merely the degree of alkyl-substitution has dropped compared with the start of run. With further increase of run time, carbon deposition reaches a steady state (240 h). As the analysis of a spent HDM catalyst (6500 h) from an industrial ARDS unit shows, throughout the following months of operation the porous hydrogen rich coke is increasingly converted into highly condensed polynuclear aromatic coke. THF-extraction of the used catalysts (TOS; 1, 12, 120, and 6500 h) has mainly removed small aromatic compounds with a high degree of alkyl-substitution.

Methods selected for the characterization of reservoir fluids have significant impact on the estimation of physical properties and phase behavior needed in reservoir simulation for petroleum production. Characterization of reservoir fluids involves representing the fluid as a continuous, semi-continuous mixture or through a number of components/pseudocomponents with known basic characterization data. Understanding of various characterization schemes and their limitations is the key to selecting the right one in a reservoir simulator. Methods of characterization largely depend on the nature of reservoir fluid, and the type of available data for the fluid. The minimum data on the heptane-plus fraction of a reservoir fluid is specific gravity, and the complete data is the SCN analysis with molecular weight and density for each group. In this paper various options for characterization of different types of reservoir fluids and crude oils with respect to the type of available data and their limitations are presented. It is shown that for a light crude with only specific gravity available, it would be possible to obtain a good distillation curve. Type of data and the impact of characterization method on phase behavior and properties of reservoir fluids are also presented.

Poly(ethylene terephthalate) (PET) was modified using methyl hydroquinone diacetate (MHQDA) and terephthalic acid (TA) to develop copolyester membranes for pervaporation separation. These membranes are expected to have improved thermomechanical properties. Two different polymer compositions (PET 70/30 (MHQDA+TA) and PET 50/50 (MHQDA+TA)) were synthesized using the melt polymerization route. The melt polymerization kinetics of these systems are reported. Two different polyesterification catalysts sodium acetate and potassium acetate were tried at 280°C, 290°C and 300°C. The polycondensations were found to obey second order kinetics irrespective of whether the reaction was catalyzed or uncatalyzed. No breaks were observed in the kinetic plots suggesting the absence of different kinetic regime during the course of the reaction. An elaborate kinetic model that presupposes a steady state approach to the reaction fits the experimental data accurately. Activation energy values for the first rate constant ( k 1 ) for uncatalyzed PET 70/30 (MHQDA+TA) and PET 50/50 (MHQDA+TA) lie between 100 and 150 kJ mol −1 while for reactions catalyzed using sodium acetate and potassium acetate the values were between 25 and 40 kJ mol −1 . Differential scanning analysis of the copolyester reveals that PET 70/30 (MHQDA+TA) and PET 50/50 (MHQDA+TA) are liquid crystalline in nature.

Layered semicrystalline silico-alumino-titanate (Si−Al−Ti) mixed oxides were synthesized by a modified sol-gel method with hydrothermal synthesis temperatures less than 200°C and autogenic pressure. The solid products are semicrystalline materials with a surface area of 136–367 m2/g and a monomodal pore size distribution with an average pore diameter of 36–47 A. The catalytic activity for pyrene hydrogenation in a batch reactor at 300°C and 500 psig was determined for sulfided Ni−Mo supported on the Si−Al−Ti mixed oxide. The activity was a function of the support composition, the heat treatment before and after loading the active metals, the addition of organic templates, and different methods of metal loading. The most active sulfided Ni−Mo/Si−Al−Ti catalyst has an activity in the same range as the commercial catalyst, Shell 324, but the metal loading is 37% less than the commercial catalyst.