Impacts of compound properties and sediment characteristics on the sorption behaviour of pharmaceuticals in aquatic systems

Sorption is a key factor in determining the persistence, attenuation and bioavailability of sediment-associated contaminants. However, our understanding of the sorption behaviour of pharmaceuticals in sediments is poor. In this study, we investigated the sorption behaviour of a diverse set of pharmaceuticals in a range sediment types. Sorption affinity of pharmaceuticals for all sediments was found to increase in the order mefenamic acid <cimetidine <atenolol <amitriptyline <diltiazem. Comparison of the experimental observations with predictions from an existing model for estimating sorption revealed the model worked poorly for the study pharmaceuticals. Multiple linear regression analysis was therefore used to develop new models for estimating sorption of individual pharmaceuticals based on sediment properties. The analyses indicated that sorption is related to properties such as Log Dow of a compound in the sediment (lipophilicity corrected for the sediment pH), cation exchange capacity, clay%, organic carbon content and exchangeable Ca2+, although, with the exception of atenolol, robust relationships between sediment properties and sorption were not obtained. Overall, the results demonstrate how complex the processes are that drive the sorption of pharmaceuticals in sediments and highlight the need for generation of further experimental data and further model development work

Application of fractional sub-equation method to nonlinear evolution equations

In this paper, we constructed a traveling wave solutions expressed by three types of functions, which are hyperbolic, trigonometric, and rational functions. By using a fractional sub-equation method for some space-time fractional nonlinear partial differential equations (FNPDE), which are considered models for different phenomena in natural and social sciences fields like engineering, physics, geology, etc. This method is a very effective and easy to investigate exact traveling wave solutions to FNPDE with the aid of the modified Riemann–Liouville derivative

Severe Pulmonary Involvement in Leptospirosis : Alternate antibiotics and systemic steroids

Pulmonary complications in leptospirosis, though common, are often unrecognized in a non-endemic area. We report here a patient with leptospirosis and severe pulmonary involvement who was treated with meropenem (1 g every 8 hours), moxifloxacin (400 mg once daily), and high doses of corticosteroids. Systemic steroids were continued for 3 months because of persistent pulmonary lesions

Circulating leukocyte telomere length is highly heritable among families of Arab descent

Background Telomere length, an indicator of ageing and longevity, has been correlated with several biomarkers of cardiometabolic disease in both Arab children and adults. It is not known, however, whether or not telomere length is a highly conserved inheritable trait in this homogeneous cohort, where age-related diseases are highly prevalent. As such, the aim of this study was to address the inheritability of telomere length in Saudi families and the impact of cardiometabolic disease biomarkers on telomere length. Methods A total of 119 randomly selected Saudi families (123 adults and 131 children) were included in this cross-sectional study. Anthropometrics were obtained and fasting blood samples were taken for routine analyses of fasting glucose and lipid profile. Leukocyte telomere length was determined using quantitative real time PCR. Results Telomere length was highly heritable as assessed by a parent-offspring regression [h2 = 0.64 (p = 0.0006)]. Telomere length was modestly associated with BMI (R2 0.07; p-value 0.0087), total cholesterol (R2 0.08; p-value 0.0033), and LDL-cholesterol (R2 0.15; p-value 3 x 10-5) after adjustments for gender, age and age within generation. Conclusion The high heritability of telomere length in Arab families, and the associations of telomere length with various cardiometabolic parameters suggest heritable genetic fetal and/or epigenetic influences on the early predisposition of Arab children to age-related diseases and accelerated ageing

A new simple route for synthesis of cadmium(II), zinc(II), cobalt(II), and manganese(II) carbonates using urea as a cheap precursor and theoretical investigation

ABSTRACT. The MnCO3.H2O, CoCO3.4H2O, ZnCO3, and CdCO3, respectively, were synthesized through a new precise, easy pathway for the reaction of MnI2, CoI2, ZnI2, or CdI2 aqueous solutions with a cheap precursor-urea for 10 h at ~ 70 oC. The IR spectra of reaction products designate the presence of characteristic bands of ionic carbonate, CO32– and absence of the individual bands of urea. The (CO3)2- ion is planar and therefore, it belongs to the D3h symmetry. It is expected to display four modes of vibrations. The stretching vibrations of the type; n(C-O) is observed in the range of (1376-1503) cm-1 while another stretching vibration n(C-O) is observed in the region 1060-1079 cm-1. The out of plane of vibration d(OCO) is observed in the range of (833-866) cm-1 while, the angle deformation bending vibration d(OCO) appear in the range of (708-732) cm-1. The infrared spectra of metal carbonate, show that, this product clearly has an uncoordinated water. The band related to the stretching vibration n(O-H) of uncoordinated H2O is observed as expected in the range of ~ 3000 cm-1. A general mechanism explaining the synthesis of carbonate compounds of cadmium(II), zinc(II), cobalt(II), and manganese(II), are described. Moreover, the DFT outcomes using B3LYP/LanL2DZ (basis set) agree with the experimental results. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; KEY WORDS: Carbonate, CoI2, Infrared spectra, Urea, DFT &nbsp; Bull. Chem. Soc. Ethiop. 2022, 36(2), 363-372. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; DOI: https://dx.doi.org/10.4314/bcse.v36i2.10&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp

FACTORS AFFECTING THE DISSIPATION OF PHARMACEUTICALS IN FRESHWATER SEDIMENTS

Degradation is one of the key processes governing the impact of pharmaceuticals in the aquatic environment. Most studies on the degradation of pharmaceuticals have focused on soil and sludge with fewer exploring persistence in aquatic sediments. Here we investigate the dissipation of six pharmaceuticals from different therapeutic classes in a range of sediment types. Dissipation of each pharmaceutical was found to follow first-order exponential decay. Half-lives in the sediments ranged from 9.5 d (atenolol) to 78.8 d (amitriptyline). Under sterile conditions, the persistence of pharmaceuticals was considerably longer. Stepwise multiple linear regression analysis was performed to explore the relationships between half-lives of the pharmaceuticals, sediment physicochemical properties and the sorption coefficients for the compounds. Sediment clay, silt and organic carbon content and microbial activity were the predominant factors related to the degradation rates of diltiazem, cimetidine and ranitidine. Regression analysis failed to highlight a key property which may be responsible for observed differences in the degradation of the other pharmaceuticals. The present study results suggest degradation rate of pharmaceuticals in sediments is determined by different factors and processes and does not exclusively depend on a single sediment parameter. This article is protected by copyright. All rights reserved

Wideband millimeter-wave substrate integrated waveguide cavity-backed antenna for satellites communications

This paper presents a new type of wideband waveguide (SIW) cavity-backed patch antenna for millimeter wave (mmW). The antenna proposed applies to applications of 31-36 GHz Ka-band such as satellites communications. The SIW is intended with settings for particular slots. The antenna is constructed on Rogers RT5880 (lossy) with 2.2 dielectric constant, l.27 mm thickness, and 0.0009 loss tangent. It is simulated in the programming of computer simulation technology (CST) Microwave Studio. The simulated results show that the SIW antenna resonates across 31 to 36 GHz bands, which means that this new antenna covers all applications within this range. The reflection coefficients in targeting range are below 10 dB. The antenna achieves good efficiency and gain with 80% and 8.87 dBi respectively

Comparative Study of the Antioxidant Activity of Two Popular Green Tea Beverages Available in the Local Market of Saudi Arabia

Abstract Antioxidants have numerous applications due to their multiple roles in diminishing harmful effects of oxidative stress. The objective of this work was to highlight the importance of green tea by evaluating the antioxidant activity of the most popular green tea brands in Saudi Arabia, Lipton and Rabea. To our knowledge, no studies have so far been done to estimate the antioxidant activity of these brands. To determine the antioxidant activities of these two brands, 10 mg/ml of each brand was extracted and their total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity, ferric reducing power and ferrous ion chelating effect were measured. The TPC of Lipton tea was 678.7 µg of gallic acid equivalents (GAE)/10mg, whereas in Rabea tea, the TPC was 647.1 µg GAE/10mg. The presence study indicated that there were no significant differences in total phenolic contents and the percentage inhibition as shown in DPPH and H 2 O 2 assays among Lipton and Rabea green teas. Moreover, it was found that all assays have exhibited high antioxidant activity in both green teas. In conclusion, our study showed evidence for evenness and stability of the antioxidant activity of the two commercial green teas available in the markets of Saudi Arabia. Continued researches are needed to further the current knowledge on the health-promoting effects of this popular beverage using different supplements by different mechanisms

An improved model and performance analysis for grid-connected photovoltaic system in Oman

The PV systems' sources are environmentally friendly, but at the same time, they are constantly changing with time. When evaluating solar energy resources, it is necessary to consider the variability and effects of different environmental operation parameters like solar irradiances, ambient temperature, and module temperature. The study introduces a method to simulate an existing photovoltaic system using a mathematical model that permits intelligent strategies to optimise the efficiency and adjust the most effective operational parameters for the solar energy systems. A mathematical analysis for the data framework, including correlation and regression coefficients, was calculated to identify and chart the relationships between the system's most influential parameters and the generated power from the PV system. An improved mathematical model was built with the most influential parameters. The improved model was simple, accurate, and based on the loss ratio by eliminating the unknown parameters. The system's efficiency was analysed using an existing data framework-recorded hourly from 1 January 2017 to December 2018 for a grid-connected photovoltaic system installed in the south of Oman. The results showed that the most influential parameters on the efficiency were the module's solar irradiance and surface temperature. The operating parameters such as ambient temperature, wind speed, and air humidity had a negligible effect on the generated power compared to the cell temperatures and solar radiation. The dissipation factor was used in the new output current and voltage equations to stimulate the output power of the PV model. The improved model was validated in a MATLAB Simulink and showed a more promising output with a lower RMSE of 5 %. [Abstract copyright: © 2022 The Author(s).

Evaluating the appropriateness of carbapenem and piperacillin-tazobactam prescribing in a tertiary care hospital in Saudi Arabia

Background: Antimicrobial resistance (AMR) is presently considered an emergent major global public health concern and excessive and/or inappropriate use of broad-spectrum antimicrobials contribute to the development of AMR. Objective: To evaluate the appropriateness of carbapenems and piperacillin-tazobactam use in a tertiary care hospital. Methods: A retrospective, observational, cross-sectional, drug-utilization study was conducted. The study included all adult hospitalized patients who had received at least one dose of the antimicrobials during their admission for the period between 1 January 2016 and 31 December 2017. The appropriateness of antimicrobial therapy was evaluated according to the Infectious Diseases Society of America (IDSA) guidelines with the consideration of the institutional antibiogram. Results: Overall, 2731 patients received 5005 courses with one of the antimicrobials, for a total of 5045.9 defined daily doses (DDD) of imipenem-cilastatin, 6492.3 of meropenem and 15,595 of piperacillin-tazobactam (4.93, 6.34 and 15.24 DDD/100 bed days, respectively). The mean age of the patients who received either antimicrobial was 55.5 ± 20.3 years, with a 14-day average length of hospital stay. About half (52%) of the prescriptions were written for patients treated in the medical ward. Pneumonia (26.6%) and sepsis (24.9%) were the most common indication for the initiation of antimicrobial therapy. Of the assessed prescriptions, only 2787 (56.5%) were prescribed appropriately, with 2142 (43.5%) deemed inappropriate. The three most common reasons for inappropriate prescription were: the spectrum of activity was too broad (44.6%), followed by antimicrobial use without culture request (32.4%), and failure of suitable antimicrobial de-escalation (19.9%). Conclusions: The study indicates that the overall rate of inappropriateness was high, emphasizing the need to develop initiatives to effectively improve broad-spectrum antimicrobial prescribing