Study of isotherm and kinetic models of lanthanum adsorption on activated carbon loaded with recently synthesized Schiff’s base

AbstractA new effective adsorbent was developed for a selective extraction and determination of lanthanum from aqueous media by use of inductively coupled plasma-optical emission spectrometry. The new adsorbent was based on activated carbon modified with Schiff’s base derived from diethylenetriamine and 3,4-dihydroxybenzaldehyde (AC-DETADHBA). Isotherm and kinetic models were systematically investigated to evaluate the analytical potential of the AC-DETADHBA phase toward La(III) by employing a batch adsorption technique. Surface properties of AC-DETADHBA were characterized by Fourier transform infrared spectrometry. The maximum static adsorption capacity was determined to be 144.80mgg−1 at pH 6, providing that the adsorption capacity of La(III) was improved by 61.79% with the AC-DETADHBA phase as compared to the carboxylic acid derivative of activated carbon after only 1h contact time. Adsorption isotherm results demonstrated that the adsorption process was mainly monolayer on a homogeneous adsorbent surface, confirming the validity of Langmuir adsorption isotherm model. Data obtained from kinetic models study indicated that the adsorption of La(III) onto the AC-DETADHBA phase obeyed a pseudo second-order kinetic model. In addition, results of thermodynamic investigation also revealed that the adsorption mechanism of AC-DETADHBA toward La(III) is a general spontaneous process and favorable. The effect of several coexisting metal ions displayed that the recovery of La(III) was not affected by the medium composition containing either individual or mixed metals. Finally, the newly proposed method gave satisfactory results for the determination of La(III) in environmental water samples

The impact of law enforcement on the dispensing antibiotics without prescription in Saudi Arabia : findings and implications

Background: Dispensing of antibiotics without a prescription (DAwP) has been widely practised in Saudi Arabia despite being illegal. This is a concern increasing AMR. In May 2018, the law and regulations were enforced including fines up to 100,000 SR (equivalent to US$26,666) and cancellation of licences. Consequently, we wanted to evaluate the impact. Methods: Mixed method study among 116 community pharmacies in two phases. Pre-law enforcement phase between December 2017 and March 2018 and post-law enforcement phase one year later. Each phase consisted of a cross-sectional questionnaire-based survey and a simulated client method (SCM). In the SCM, clients presented with either pharyngitis or urinary tract infections (UTI) with 3 levels: level 1 – SC asked for something to relieve the symptoms, level 2 – SC asked for something stronger if an antibiotic was not dispensed, level 3 – SC requested an antibiotic. In SCM for each phase, all 116 pharmacies were visited with at least one of the scenarios. Results: Before the law enforcement, 70.7% of community pharmacists reported DAwP was common. 96.6% and 87.7% of participating pharmacies dispensed antibiotics without a prescription for pharyngitis and UTI respectively. After law enforcement, only 12.9% of community pharmacists indicated that DAwP was common, with only 12.1% and 5.2% dispensing antibiotics without prescriptions for pharyngitis and UTI respectively and mostly after level 3. Conclusion: Law enforcement was effective. However, there is still further scope for improvement as community pharmacists are worried patients may go elsewhere if no antibiotic dispensed on request. This could include educational activities

Surfactant Modified/Mediated Thin-Layer Chromatographic Systems for the Analysis of Amino Acids

This review incorporates a large number of chromatographic systems modified by the surfactants. A large number of solvent systems and stationary phases are summarized in this paper. Three different kinds of surfactants (anionic, cationic, and nonionic) are used as modifiers for stationary phases as well as solvent systems. Surfactants are used at all the three different concentration levels (below, above, and at critical micelle concentration) where surfactants behave differently. Modifications of both stationary phases and solvent systems by surfactants produced a new generation of chromatographic systems. Microemulsion solvent systems are also incorporated in this paper. Microemulsion thin-layer chromatography is a new approach in the field of chromatography

The impact of law enforcement on dispensing antibiotics without prescription: a multi-methods study from Saudi Arabia

Background: Dispensing of antibiotics without a prescription (DAwP) has been widely practised among community pharmacies in Saudi Arabia despite being illegal. However, in May 2018, the law and regulations were enforced alongside fines. Consequently, we wanted to evaluate the impact of these changes. Methods: A study was conducted among 116 community pharmacies in two phases. A pre-law enforcement phase between December 2017 and March 2018 and a post-law enforcement phase one year later. Each phase consisted of a cross-sectional questionnaire-based survey and a simulated client method (SCM) approach. In the SCM, clients presented with either pharyngitis or urinary tract infections (UTI). In SCM, for each phase, all 116 pharmacies were visited with one of the scenarios. Results: Before the law enforcement, 70.7% of community pharmacists reported that DAwP was common with 96.6% and 87.7% of participating pharmacies dispensed antibiotics without a prescription for pharyngitis and UTI respectively. After the law enforcement, only 12.9% reported that DAwP is still a common practice, with only 12.1% and 5.2% dispensing antibiotics without prescriptions for pharyngitis and UTI respectively. Conclusion: law enforcement was effective. However, there is still further scope for improvement. This could include further educational activities with pharmacists, physicians and the public

Free-Standing Hierarchically Sandwich-Type Tungsten Disulfide Nanotubes/Graphene Anode for Lithium-Ion Batteries

Transition metal dichalcogenides (TMD), analogue of graphene, could form various dimensionalities. Similar to carbon, one dimensional (1D) nanotube of TMD materials has wide application in hydrogen storage，Li-ion batteries and supercapacitors due to their unique structure and properties. Here we demonstrate the feasibility of tungsten disulfide nanotubes (WS2-NTs)/graphene (GS) sandwich-type architecture as anode for lithium-ion batteries for the first time. The graphene based hierarchical architecture plays vital roles in achieving fast electron/ion transfer, thus leading to good electrochemical performance. When evaluated as anode, WS2-NTs /GS hybrid could maintain a capacity of 318.6 mA/g over 500 cycles at a current density of 1A/g. Besides, the hybrid anode does not require any additional polymetric binder, conductive additives or a separate metal current-collector. The relatively high density of this hybrid is beneficial for high capacity per unit volume. Those characteristics make it a potential anode material for light and high performance lithium-ion batteries

A Simple and Reliable Liquid Chromatographic Method for Simultaneous Determination of Five Benzodiazepine Drugs in Human Plasma

Benzodiazepines (BZDs) are one of the most important drugs that have been used in the treatment of neuropsychological disorders. Indeed, BZDs are abused by drug addicts regardless of their therapeutic uses. Therefore, it was important in forensic and clinical toxicology to reach an easy and reliable method for the screening and quantification of BZDs in the human plasma matrix. In the current work, five BZDs, namely bromazepam, clonazepam, lorazepam, nordiazepam and diazepam were simultaneously separated and detected by a simple and reliable RPLC method in a human plasma matrix. Isocratic mobile elution consisting of 20 mmol L−1 phosphate buffer (pH 7.0) and methanol (50:50, v/v) on a Symmetry C18 column was employed. The flow rate, wavelength and column temperature were fixed at 1.0 mL min−1, 214 nm and 40 °C, respectively. The proposed method was validated, giving a linearity within the concentration ranges 5–500 ng mL−1 for bromazepam and diazepam, 3–500 ng mL−1 for clonazepam and lorazepam and 1–500 ng mL−1 for nordiazepam with a determination coefficient (R2) more than 0.9992. The LOD values for the selected BZDs ranged from 0.54 to 2.32 and from 1.78 to 7.65 ng mL−1 for standard methanolic and plasma matrices, respectively. Precision, accuracy, selectivity, stability, and robustness were some of the terms considered in validating the current RPLC method. Based on these results, a simple and reliable RPLC method was successfully applied to quantify BZDs in human plasma matrix appearing with recoveries ranging from 96.5 to 107.5% and interday RSD less than 4%. The current developed method was useful for rapidly screening the most commonly used BZDs in the market within their therapeutic concentration ranges

Enhancement of Maize Growth Using Some Plant Growth Promoting Rhizobacteria (PGPR) Under Laboratory Conditions

Abstract: Thirty one bacterial isolates were isolated and identified in nine genera, with twelve taxa as Pseudomonas putida, P. fluorescens, P. areuginosa, Serratia marcences, Xanthomonas sp., Bacillus cereus, Microccoucs sp., B. subtilis, B. megaterium, B. amyloliquefaciencs, Pseudomonas sp., Staphylococcus sp. The highest percentage distribution was B. subtilis, followed by P. putida, P. areuginosa and S. marcences. Eight isolates had the ability for production of IAA and siderophores. S. marcences then P. putida followed by P. fluorescens were the highest in IAA production. The eight isolates of PGPR were increased seed germination by 7 to 13% over control. The highest seed germination was recorded when seeds were pretreated with S. marcences, then P. putida followed by B. subtilis. The highest seedling height and shoot dry weight were observed in seeds treated with S. marcences then P. putida followed by B. cereus and B. subtilis. The use of S. marcences produced the highest root length and weight, and also increased the chlorophyll contents. The MDG was the highest in case of seed soaking and inoculums added with irrigation water treatments, while was the lowest at spry the inoculums on the soil surface. Also, the best results for MGT and GI was found in seed soaking and inoculums added with irrigation water treatments. The best PGPR bacteria for MDG, MGT and GI in seed soaking treatment were B. megaterium, P. putida, S. marcences and P. areuginosa, while in adding inoculums with irrigation water were B. subtilis, B. cereus, S. marcences and P. fluorescens. When cultured the high efficacy isolates of Serratia marcences with Pseudomonas pitida and Bacillus subtilis without any antagonistic effect between them

Hospitalization rate and outcomes in patients with left ventricular dysfunction receiving hemodialysis

Marwan A Albeshri,1 Mohammed S Alsallum,1 Sulafa Sindi,1 Mohammed Kadi,1 Abdullah Albishri,2 Hanadi Alhozali,3 Kamal Alghalayini3 1College of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; 2College of Medicine, King Abdulaziz University-Rabigh Branch, Rabigh, Saudi Arabia; 3Department of Internal Medicine, King Abdulaziz University Hospital, Jeddah, Saudi Arabia Introduction: Left ventricular dysfunction (LVD) is characterized as left ventricular ejection fraction (EF) below half of the systolic capacity of the left ventricle. Patients on hemodialysis have higher risk of developing LVD than the general population. Our aim was to assess hospitalization rate and outcomes in hemodialysis patients with LVD.Patients and methods: All patients ≥18 years old, who started hemodialysis therapy at King Abdulaziz University Hospital between January 2011 and December 2011, were identified using medical records of hemodialysis unit. Patients were then divided into three groups, according to their EF results prior to the initiation of hemodialysis, as patients with EF <40%, EF between 40% and 49%, and EF ≥50%. Patients were then followed for 5 years by reviewing their hospital records to assess their outcomes, hospital admissions, and length of hospital stay.Results: Analysis included 333 patients. Patients with EF <40% were 40, 36 patients with EF 40%–49%, and 257 patients had an EF >50%. Patients with EF <50% were significantly older than patients with EF >50% (P=0.002). Diabetes mellitus and hypertension were more prevalent in patients with EF <40% and EF 40%–49% when compared with patients with EF >50% (P<0.001, P=0.002). The average length of stay between the three groups was significantly different (P=0.007). Intensive care unit admissions were significantly different when comparing the three groups (P=0.013) and was found to be an independent risk factor for mortality in our patients. Half of the patients with EF <40% and 44% of patients with EF of 40%–49% died compared with only 27% of patients with EF >50% (P=0.002). However, Kaplan–Meier analysis showed no significant difference in the survival time among the three groups (P=0.845).Conclusion: Mortality and morbidity increased in patients with LVD on hemodialysis compared with patients with normal EF. Keywords: LVD, hemodialysis, mortality, hospitalization&nbsp