Feasibility of polymer enhanced ultrafiltration (PEUF) for heavy metals retention under competitive conditions.

Heavy metals are valuable resources for the modern world; however, they are potentially hazardous. Contamination exists in aqueous waste streams of many industries, such as metal plating facilities, mining operations, and tanneries. The soils surrounding many military and industrial sites are also contaminated and pose a risk of metals groundwater and surface water contamination. Some metals associated with these activities are cadmium, chromium, lead, and mercury. Heavy metals are not biodegradable and tend to accumulate in living organisms, causing various diseases and disorders. However, heavy metals have a high commercial value if they can be recovered in pure form. Polymer enhanced ultrafiltration (PEUF) was investigated because it offers the potential to selectively recover metals rapidly from solutions containing low concentrations. However, the major drawback (complex solutions containing other chelators and competitors) of these processes have not been investigated in detail and a fundamental understanding of these processes in real systems is required to truly assess and exploit their potential. The aim of this project was to investigate the performance of PEUF for metal ions filtration in batch mode and continuous feeding using metals, individual and in mixtures, metal binding chelator and competitor. A variety of feed compositions were used, and metal ions retention profiles were determined. The competition from other chelators or competitors for metal ions was investigated in the presence of PEI. The binding mechanisms of metal ions were explored and the ability of the Langmuir isotherm model to describe these systems using a batch and continuous feed was determined. Based on the principal of mass balance and Langmuir adsorption isotherms, a mathematical model describing the continuous feed of PEUF was developed. Ultrafiltration experiments were carried out in the stirred dead-end ultrafiltration cell and cross flow ultrafiltration systems. The metals investigated were: Cu2+, Zn2+, Ni2+, Cr6+, Co2+ and Cd2+. The results showed that adding PEI to metal ion solutions significantly increases the retention of the metal ions in the solution to greater than 90% at its best. However, the addition of the polymer significantly reduces the flux of the process (by approximately 50%) for equivalent solution conditions. Membrane surface charge is also a factor which is critical to the process performance. In general, the highest retention of metal ions occurred when the membrane had its highest negative charge. The results of the binding studies showed that the Langmuir isotherm offers a better description of the binding process than the Freundlich isotherm. The work reported here showed that competition for ions from other chelators or competitors is possible and change the performance compared to ideal simple systems. It also showed some potential advantages of this approach by changing capacity and selectivity of the separation based on PEUF processes. Under competitive conditions with chelators and competitors, maximum capacities of metal ions bind to PEI using Langmuir isotherm in continuous feed of PEUF were greater than those obtained from batch system, they were similar for Cu2+-PEI complex in single and mixed metals solutions of both systems. The model developed in this project showed good predictions of the experimental results with minor exception in the case of strongly competitive situations

The Effect of ESP Program on the Engineering Students' Proficiency at the University of Tabuk

This study  aims to assess an ESP program  for engineering students in the University of  Tabuk  that caters for the needs in the second semester 1432/1433AH  and subsequently to assess its effect on students ' achievement in their field. More specifically, it   addressed the following question: 1) What is the effect of the engineering   ESP program on the students' achievement in English? The sample of the study consists of 50   students of two sections from the engineering faculty in the University of Tabuk. An experimental group was taught the proposed engineering ESP program while the control group was taught the ordinary course in the University of Tabuk. Compared to the control group, the students in the experimental group made significantly higher progress in general on all components of the English proficiency test. The differences between the mean scores of the two groups on the posttest were statistically significant for every component of English language. Based on the findings of the study, the University of Tabuk is recommended to give priority to ESP courses to improve the student's level in English language and to allocate more funds for these programs. Key words: ESP, EOP, EAP, EST

Recent advances in the analysis of macromolecular interactions using the matrix-free method of sedimentation in the analytical ultracentrifuge

Sedimentation in the analytical ultracentrifuge is a matrix free solution technique with no immobilisation, columns, or membranes required and can be used to study self-association and complex or “hetero”-interactions, stoichiometry, reversibility and interaction strength of a wide variety of macromolecular types and across a very large dynamic range (dissociation constants from 10−12 M to 10−1 M). We extend an earlier review specifically highlighting advances in sedimentation velocity and sedimentation equilibrium in the analytical ultracentrifuge applied to protein interactions and mucoadhesion and to review recent applications in protein self-association (tetanus toxoid, agrin), protein-like carbohydrate association (aminocelluloses), carbohydrate-protein interactions (polysaccharide-gliadin), nucleic-acid protein (G-duplexes), nucleic acid-carbohydrate (DNA-chitosan) and finally carbohydrate-carbohydrate (xanthan-chitosan and a ternary polysaccharide complex) interactions

CYTOCHROME P450 CYP1B1*2 GENE AND ITS ASSOCIATION WITH T2D IN TABUK POPULATION, NORTHWESTERN REGION OF SAUDI ARABIA

Objective: Cytochrome P450 1B1 (CYP1B1) is involved in the activation of procarcinogens and steroid metabolism. Genetic variants of CYP1B1are associated with altered catalytic activity and disease phenotypes. The purpose of this study was to investigate the role of CYP1B1 (rs1056827) polymorphism in inducing T2D.Methods: This cross-sectional study enrolled 113 subjects of T2D and 120 controls. DNA was isolated from blood. Genotyping of the rs1056827 wasdone by allele-specific polymerase chain reaction. The frequency of alleles and genotype distribution was compared in T2D cases and healthy controls.Statistical analysis was performed with SPSS, Chi-square, and Fisher exact test. Hardy-Weinberg equilibrium was tested by a χ2 test. The associations between rs1056827 variant genotypes and T2D were estimated by computing the odds ratios and their 95% confidence intervals (CI) from univariate and multivariate logistic regression analysis.Results: A significant association of rs1056827 was found between T2D cases and controls (p<0.0001). When GG genotype was compared with GT genotype a significant association was found with odd ration (OD)0.24 (95% CI: (0.131–0.452) and risk ratio (RR) 0.45 (0.30–0.67) times the risk of T2D heterozygous with the G/T allele (p≤0.0002). In a comparison of GG homozygous with the TT homozygous, there was no significant association with the OD 0.38 (95% CI: (0.02–6.51) RR 0.55(0.13–2.35), p<0.49. When G allele was compared with the T allele a highly significant association with OD 0.54 (95% [CI]: (0.37–0.80) RR 0.75(0.630–0.897) < p≤0.003 suggesting a possible dominant effect of this polymorphism on T2D risk.Conclusion: This result suggests a significant association between rs1056827G>T polymorphism and T2D. This finding is limited due to the smaller sample size and can be validated by large sample size studies

Systemic Review and Clinical Management in Diagnosis and Treatment of the Iron Deficiency Anemia in Adults

This study aimed at exploring with a systematic review the clinical management in diagnosis and treatment of the iron deficiency anemia in adults, as the iron deficiency is the most frequent cause of anemia worldwide. And it impairs quality of life, increases asthenia and can lead to clinical worsening of patients. In addition, iron deficiency has a complex mechanism whose pathologic pathway is recently becoming better understood. This review summarizes the current knowledge regarding diagnostic algorithms for iron deficiency anemia. The majority of aetiologies occur in the digestive tract, and justify morphological examination of the gut. First line investigations are upper gastrointestinal endoscopy and colonoscopy, and when negative, the small bowel should be explored; newer tools such as video capsule endoscopy have also been developed. The treatment of iron deficiency is aetiological if possible and iron supplementation whether in oral or in parenteral form

Freshwater microalgae-based wastewater treatment under abiotic stress

Wastewater treatment by microalgae is an eco-friendly and sustainable method for pollutant removal and biomass generation. Microalgae production under abiotic stress (such as salinity/salt stress) has an impact on nutrient removal and fatty acid accumulation. In this study, a freshwater microalgal strain (Desmodesmus communis GEEL-12) was cultured in municipal wastewater with various NaCl concentrations (ranging from 25–150 mM). The growth kinetics and morphological changes of the microalgae were observed. The nutrient removal, salinity change, fatty acid composition, and biodiesel quality under various groups were also investigated. The maximum growth of D. communis GEEL-12 was observed in the control group at 0.48 OD680nm. The growth inhibition was observed under high salt conditions (150 mM), which showed poor tolerance with 0.15 OD680nm. The nitrogen (N) and phosphorus (P) removal significantly decreased from 99–81% and 5.0–5.9% upon the addition of 100–150 mM salt, respectively. Palmitic acid (C16:0) and stearic acid (C18:0) were the most common fatty acid profiles. The abundance of C18:0 enhanced from 49.37%–56.87% in D. communis GEEL-12 upon high NaCl concentrations (100–150 mM). The biodiesel quality index of D. communis GEEL-12 under 50–75 mM salt concentrations reached the levels advised by international standards

Head and Neck Surgery: A Differential Diagnosis in Otolaryngology

Introduction: In otolaryngology of the head and neck surgery; differential diagnosis is a practical and comprehensive guide that is organized uniquely by signs and symptoms instead of by diseases. Aim: This study will describe the keys to diagnostic evaluation and differential diagnosis of presenting symptoms for problems affecting each otolaryngology organ system.Methods: Each symptom opens with the patient’s presentation followed by an easily accessible list of potential diagnoses and supplementary data on the features of the different diseases to help correctly identify the problem. And identify features labeled by signs and symptoms, not by disease, and then enable quick clinical reference In-depth coverage of the diagnostic and treatment evaluation of all ENT disorders.

Perceived Risk of falls among Acute Care Patients

Purpose: In an effort to lower the number of falls that occur among hospitalized patients, several facilities have begun introducing various fall prevention programs. However, the efficacy of fall prevention programs is diminished if patients do not consider themselves to be at risk for falls and do not follow recommended procedures. The goal of this study was to characterize how patients in four different acute care specialist services felt about their risk of falling while in the hospital. Methods: One hundred patients admitted to the study hospital with a Morse Fall Scale score of 45 or higher were given the Patient Perception Questionnaire, a tool designed to assess a patient's perception of their own fall risk, fear of falling, and motivation to take part in fall prevention efforts. Scores on the Morse Fall Scale were gathered through a historical assessment of medical records. Descriptive statistics, Pearson's correlation coefficients, and independent sample t tests were used to examine the data. Results: The average age was 65, and around half (52%) were men and half (48%) were women. Based on their ratings on the Morse Fall Scale, all 100 participants were classified as being at high risk for falls. However, only 55.5% of the individuals agreed with this assessment. The likelihood that a patient would seek assistance and the degree to which they feared falling both declined as their faith in their mobility improved. Patients hospitalized after a fall exhibited considerably lower confidence scores and greater fear scores than patients who had not been injured in a fall. Conclusions: Patients who have a high fall risk assessment score may not believe they are at risk for falls and may not take any steps to reduce their risk. The prevalence of falls in hospitals might be mitigated by the creation of a fall risk assessment technique that takes into account both objective and subjective factors

Application of recent advances in hydrodynamic methods for characterising mucins in solution

Mucins are the primary macromolecular component of mucus—nature’s natural lubricant—although they are poorly characterised heterogeneous substances. Recent advances in hydrodynamic methodology now offer the opportunity for gaining a better understanding of their solution properties. In this study a combination of such methods was used to provide increased understanding of a preparation of porcine intestinal mucin (PIM), MUC2 mucin, in terms of both heterogeneity and quantification of conformational flexibility. The new sedimentation equilibrium algorithm SEDFIT-MSTAR is applied to yield a weight average (over the whole distribution) molar mass of 7.1 × 106 g mol−1, in complete agreement with size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS), which yielded a value of 7.2 × 106 g mol−1. Sedimentation velocity profiles show mucin to be very polydisperse, with a broad molar mass distribution obtained using the Extended Fujita algorithm, consistent with the elution profiles from SEC-MALS. On-line differential pressure viscometry coupled to the SEC-MALS was used to obtain the intrinsic viscosity [η] as a function of molar mass. These data combined with sedimentation coefficient data into the global conformation algorithm HYDFIT show that PIM has a flexible linear structure, with persistence length Lp ~10 nm and mass per unit length, ML ~2380 g mol−1 nm−1, consistent with a Wales-van Holde ratio of ~1.2 obtained from the concentration dependence of the sedimentation coefficient

The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section

BACKGROUND: The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU). METHODS: The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations. RESULTS: The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations. CONCLUSION: The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available