A Tribute to Mel Byers

Editors Comments: This is a tribute to an individual who is a special person to me. He has helped me to gain a much better understanding of the field and has expanded my thinking. I have not met a person with as much perspective and foresight. Mel is an individual who is a free thinker and innovator. He is always ready to help and put forth a maximum effort to develop the profession. His impact upon the profession has been immense. Much of the profession\u27s growth is a direct result of his leadership. A testimony to him may best be told not by his accomplishments but by his impacts upon people\u27s lives

Spectrophotometric Analysis of Vancomycin Hydrochloride in Pure and Pharmaceutical Injections via Batch and Cloud Point Extraction Techniques

تم تطوير تفاعل بسيط وحساس لتقدير هيدروكلوريد الفانكومايسين باستخدام طرائق الدفعة واستخلاص نقطة الغيمة (CPE)   وتعتمد الطريقة الأولى على تكوين صبغة الآزو الناتجة عن تفاعل اقتران الدابسون المؤزوت مع هيدروكلوريد الفانكومايسين في الوسط القاعدي وتم تطوير حساسية هذا التفاعل باستخدام المادة الفعالة غير الأيونية (Triton X-114) وبتقنية نقطة الغيمة. تمت إذابة صبغة الآزو المستخلصة في الطور الغني بمادة الشد السطحي في الإيثانول وقياسها طيفيًا عند الطول الموجي الاعظم 440 نانومتر. تم تقدير التفاعل باستخدام كل من الطرائق الدفعة وطريقةCPE  (أي مع الاستخلاص وبدونه) وتم إجراء مقارنة بسيطة بين الطريقتين. وقد درست جميع الظروف الكيميائية والفيزيائية لطريقتي الدُفعة والاستخلاص بنقطة الغيمة بعناية في ظل الظروف المثلى ، كانت مديات الخطية من 3 إلى 50 و 0.5-25 ميكروغرام. مل-1 لهيدروكلوريد الفانكومايسين بينما كانت حدود الكشف 0.806 و 0.462 ميكروغرام.مل-1 لطريقتي الدفعة و التحليل بالاستخلاص بنقطة الغيمة على التوالي. تمت مقارنة قيم الاستعادية التي تم الحصول عليها مع تلك التي تم الحصول عليها من تطبيق طريقة الأشعة فوق البنفسجية. استخدمت التفنيات المقترحة بفعالية عالية في تقدير الفانكومايسين في الحقن الصيدلانية.  Development of a precise and delicate reaction has been acquired for the determination of vancomycin hydrochloride using batch and cloud point extraction (CPE) methods. The first method is based on the formation of azo dye as a result of diazotized dapsone coupled with vancomycin HCl (VAN) in a basic medium. The sensitivity of this reaction was enhanced by utilizing a nonionic surfactant (Triton X-114) and the cloud point extraction technique (second method). The azo dye formed was extracted into the surfactant-rich phase, dissolved in ethanol and detected at λmax 440 nm spectrophotometrically. The reaction was investigated using both batch and CPE methods (with and without extraction), and a simple comparison between the two developed methods was made. The conditions that affect the extraction process and the sensitivity of the methods have been carefully examined. The linearity of the calibration curves was in the range of 3-50 and 0.5- 25 µg.mL-1 with limits of detection of 0.806 and 0.462 µg.mL-1 for VAN in both batch and CPE procedures, respectively. The percentage of relative standard deviation (R.S.D.%) for the two methods was better than 2.54% and 2.83%, respectively. The recommended procedures have been effectively used to assay VAN in commercial injections

Sustainable Policy Design through Integrated Basin Models: Findings from the Rio Grande

In the Rio Grande Basin, water is over-appropriated, and demands for water grow while supplies are constrained by drought and climate change. The Basin is currently in its seventh year of drought, and reservoirs are at historically low levels. Agricultural and municipal river diversions have been sharply curtailed; low flows threaten endangered species. A central policy challenge is the design and implementation of plans that allocate the Basin\u27s water supplies efficiently, fairly, and sustainably. Such plans are complicated by the demands of existing water users, potential new users, three state governments, and two sovereign nations. These challenges are addressed by designing and developing an integrated basin-wide nonlinear programming model to optimize water allocations and use levels for the Basin. The model permits a quantitative testing and analysis of whether institutional adjustments can limit damages caused by drought. It identifies changes in water uses and allocations that result from those adjustments. Compared to existing rules governing the Basin\u27s water use, future drought damages could be reduced by one-fifth to one-third per year from intrastate and interstate water markets coupled with marginal cost pricing, respectively, that permit water transfers across jurisdictions. Results show hydrologic and economic tradeoffs among water uses, regions, and drought control programs

Batch and Flow-Injection Spectrophotometric Determination of Thymol Using Procaine Hydrochloride as a New Chromogenic Reagent

New, simple and sensitive batch and Flow-injecton spectrophotometric methods for the determination of Thymol in pure form and in mouth wash preparations have been proposed in this study. These methods were based on a diazotization and coupling reaction between Thymol and diazotized procaine HCl in alkaline medium to form an intense orange-red water-soluble dye that is stable and has a maximum absorption at 474 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 0.4-4.8 and 4-80 µg.ml-1 of Thymol, with detection limits of 0.072 and 1.807 µg.ml-1 of Thymol for batch and FIA methods respectively. The FIA procedure sample throughput was 80 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were successfully applied to the determination of Thymol in mouth wash preparations

Batch and Flow-Injection Spectrophotometric Determination of Procaine HCl in Pharmaceutical Preparations Via Using Diazotization and Coupling Reaction

Simple and sensitive batch and Flow-injection spectrophotometric methods for the determination of Procaine HCl in pure form and in injections were proposed. These methods were based on a diazotization reaction of procaine HCl with sodium nitrite and hydrochloric acid to form diazonium salt, which is coupled with chromatropic acid in alkaline medium to form an intense pink water-soluble dye that is stable and has a maximum absorption at 508 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 1-40 and 5-400 µg.ml-1 of Procaine HCl, with detection limits of 0.874 and 3.75 µg.ml-1 of Procaine HCl for batch and FIA methods respectively. The FIA average sample throughput was 70 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were applied satisfactorily for the determination of Procaine HCl in an injections samples using the standard addition method

Bimetallic Pt(II)-bipyridyl-diacetylide/Ln(III) tris-diketonate adducts based on a combination of coordinate bonding and hydrogen bonding between the metal fragments: syntheses, structures and photophysical properties

The luminescent Pt(II) complex [Pt(4,4'-Bu-t(2)-bipy){CC-(5-pyrimidinyl)}(2)] (1) was prepared by coupling of [Pt(4,4'-Bu-t(2)-bipy)Cl-2] with 5-ethynyl-pyrimidine, and contains two pyrimidinyl units pendant from a Pt(H) bipyridyl diacetylide core; it shows luminescence at 520 nm which is typical of Pt(II) luminophores of this type. Reaction with [Ln(hfac)(3)(H2O)(2)] (hfac = anion of hexafluoroacetylacetone) affords as crystalline solids the compounds [1 center dot {Ln(hfac)(3)(H2O)}{Ln(hfac)(3)(H2O)(2)}] (Ln = Nd, Gd, Er, Yb), in which the {Ln(hfac)(3)(H2O)} unit is coordinated to one pyrimidine ring via an N atom, whereas the {Ln(hfac)(3)(H2O)(2)} unit is associated with two N atoms, one from each pyrimidine ring of 1, via N center dot center dot center dot HOH hydrogen-bonding interactions involving the coordinated water ligands on the lanthanide centre. Solution spectroscopic studies show that the luminescence of 1 is partly quenched on addition of [Ln(hfac)(3)(H2O)(2)] (Ln = Er, Nd) by formation of Pt(II)/Ln(III) adducts in which Pt(II)-> Ln(III) photoinduced energy-transfer occurs to the low-lying f-f levels of the Ln(Ill) centre. Significant quenching occurs with both Er(Ill) and Nd(III) because both have several f-f states which match well the (MLCT)-M-3 emission energy of 1. Time-resolved luminescence studies show that Pt(II)-Er(III) energy-transfer (7.0 x 10(7) M-1) is around three times faster than Pt(II)-> Nd(III) energy-transfer (approximate to 2 x 10(7) M-1) over the same distance because the luminescence spectrum of l overlaps better with the absorption spectrum of Er(111) than with Nd(III). In contrast Yb(111) causes no significant quenching of 1 because it has only a single f-f excited level which is a poor energy match for the Pt(II)-based excited state

Ultimate Homophones

Abstract unavailable

Zooplankton of Oman Coastal Waters

Monthly sampling during daytime was carried out in 2007-2011 at Bandar Al-Khyran (23.51oN, 58.72oE) which is the largest semi-enclosed bay on the southern end of the Sea of Oman with about 4 km2 in surface area and an average depth of 10 m. Zooplankton were represented by Copepoda (79%), Cladocera (9%), Oikopleuriddae (7%), Chaetognatha (3%), and Decapoda (~2%) comprising the major part of the total zooplankton abundance. Among copepods, 27 species constituted ~75% of total copepod abundance. Changes of copepod abundance have not had a pronounced seasonal pattern. Instead, a multiple peak structure in monthly fluctuations was observed, on the level of genera as well as the abundance of species. Amplitudes and timing of the copepod peak abundance were markedly different during the studied years

Predictors of Developing a Complex Course of Osteomyelitis in Patients with Sickle Cell Anaemia

Objective: Despite the numerous advances in management strategies, treating osteomyelitis in individuals with sickle cell disease remains a significant challenge, leading to severe long-term consequences. This study aimed to assess the key factors potentially linked to a complex progression of osteomyelitis in patients diagnosed with sickle cell disease. Methods: A cohort of thirty-four patients was identified, and their progress was monitored over a span of twelve months, during a ten-year period (2010-2020). The variables under investigation encompassed demographic and clinical traits, laboratory analyses, imaging data, as well as the strategies employed for treatment. Results: The risk prediction model has pinpointed five factors (severity of sickle cell disease, involvement of lower limbs, presence of bacteraemia, MRI findings, and utilization of surgical debridement) that exhibited an Area Under the Curve (AUC) exceeding 0.7. Causative organisms were identified in 9 out of the total cases, constituting 26.47% of the patient cohort. Among the 34 patients, 17 displayed a severe course of sickle cell disease (AUC 7.88), with MRI being highlighted as a valuable contributing factor (AUC 7.88). Furthermore, thirteen patients (38.2%) underwent surgical debridement, a procedure that yielded a statistically significant P-value of 0.012 and an AUC of 0.714. Conclusion: Osteomyelitis within the context of severe sickle cell disease, particularly when accompanied by lower extremity infection, bacteraemia, and positive MRI findings, and necessitating surgical debridement, emerges as a cluster of risk factors predisposing individuals to osteomyelitis relapse and a more intricate disease trajectory. Keywords: Sickle cell disease, Osteomyelitis, Disease Severity, Debridement, bacteraemi