Potentiometric sensors selective for Cu(II) determination in real water samples and biological fluids based on graphene and multi-walled carbon nanotubes modified graphite electrodes

162-173Three newly synthesized Cu(II) ion selective electrodes based on 1,8-dihydoxyanthraquinone (DHAQ), as an ionophore, have been developed. Carbon paste electrode has been modified with DAHQ (sensor I), graphene and DHAQ (sensor II) and multi-walled carbon nanotubes (MWCNTs) and DHAQ (sensor III), in order to improve the conductivity and transduction of chemical signal to electrical signal. Under optimized conditions, the electrodes I, II and III revealed Nernstian slopes of 29.78 ± 0.17, 30.25 ± 0.12, and 30.55 ± 0.19 mV decade-1, respectively, at 25±1 °C covering a wide concentration range from 1×10–6 to 1×10−1 mol L–1 for sensors I and II and from 1×10–5 to 1×10−1 mol L–1 for sensor III with detection limit values of 8×10−7, 5×10−7, and 3.3×10−6 mol L-1, respectively. The response of the proposed electrodes is very fast and independent of pH in the range of 2.4–6.5 and the response mechanism is studied using IR, SEM and EDX analyses. Selectivity coefficients have been determined by applying separate solution method and matched potential method, where the obtained values indicated the good discrimination of Cu(II) from other cations by the proposed sensors. The developed sensors have been used successfully for quantitative determination of Cu(II) ions in different matrix of spiked real water samples and biological fluids (urine and serum). These sensors have also been used successfully as indicator electrodes in the potentiometric titration of Cu(II) with EDTA

Potentiometric determination of oxybutynin hydrochloride in pharmaceutical formulations at modified carbon paste electrodes

324-332New potentiometric sensitive and selective modified carbon paste (MCPE) electrodes based on ion pair formation between phosphotungestic acid (PTA), sodium tetraphenyl borate (NaTPB), phosphomolybdic acid (PMA) or ammonium reineckate (RN) and oxybutynin hydrochloride (Ox.HCl) has been developed. The proposed electrodes have Nernstian slope values of 58.50±0.71, 58.71±1.20, 54.80±1.30 and 59.20±0.70 mV decade−1 for electrodes modified with 20, 10, 5 and 10 mg of Ox-TPB (electrode I), Ox-RN (electrode II), Ox-PMA (electrode III) and Ox-PTA (electrode IV) ion pairs, respectively. It is found that the dynamic drug concentration range at 25 °C is 1.0×10−5–1.0×10−2 mol L−1. The response of MCPEs is pH independent in the range 2.0–6.0 with a fast response time of 10 s for electrode I and 12 s for electrodes II-IV. These electrodes have good Nernstian response in the temperature range 10–60 °C with slope (isothermal coefficient) equal 0.791×10−3, 0.769×10−3, 0.629×10−3 and 1.277×10−3 V/°C for electrodes I, II , III and IV respectively. These small values indicate the high thermal stability of the electrodes. The MCPEs have shown a relatively long life time of 36 days. A pure and pharmaceutical formulation of Ox.HCl has quantified using calibration and standard addition methods and the obtained results agreed with that of the official HPLC method. Validation parameters have been optimized according to ICH recommendations. Limits of detection and quantification are calculated under the optimized conditions. For the analytical applications, pharmaceutical dose form has performed. Various interferents have been used to investigate the interference in the analytical application and found that the proposed method would be well adopted for real sample analysis

Potentiometric determination of oxybutynin hydrochloride in pharmaceutical formulations at modified carbon paste electrodes

324-332New potentiometric sensitive and selective modified carbon paste (MCPE) electrodes based on ion pair formation between phosphotungestic acid (PTA), sodium tetraphenyl borate (NaTPB), phosphomolybdic acid (PMA) or ammonium reineckate (RN) and oxybutynin hydrochloride (Ox.HCl) has been developed. The proposed electrodes have Nernstian slope values of 58.50±0.71, 58.71±1.20, 54.80±1.30 and 59.20±0.70 mV decade−1 for electrodes modified with 20, 10, 5 and 10 mg of Ox-TPB (electrode I), Ox-RN (electrode II), Ox-PMA (electrode III) and Ox-PTA (electrode IV) ion pairs, respectively. It is found that the dynamic drug concentration range at 25 °C is 1.0×10−5–1.0×10−2 mol L−1. The response of MCPEs is pH independent in the range 2.0–6.0 with a fast response time of 10 s for electrode I and 12 s for electrodes II-IV. These electrodes have good Nernstian response in the temperature range 10–60 °C with slope (isothermal coefficient) equal 0.791×10−3, 0.769×10−3, 0.629×10−3 and 1.277×10−3 V/°C for electrodes I, II , III and IV respectively. These small values indicate the high thermal stability of the electrodes. The MCPEs have shown a relatively long life time of 36 days. A pure and pharmaceutical formulation of Ox.HCl has quantified using calibration and standard addition methods and the obtained results agreed with that of the official HPLC method. Validation parameters have been optimized according to ICH recommendations. Limits of detection and quantification are calculated under the optimized conditions. For the analytical applications, pharmaceutical dose form has performed. Various interferents have been used to investigate the interference in the analytical application and found that the proposed method would be well adopted for real sample analysis

Improving postharvest storage of fresh artichoke bottoms by an edible coating of Cordia myxa gum

This study aimed to prolong the shelf life of fresh-cut artichoke (Cynara scolymus L.) bottoms under refrigerated conditions (2 °C and 95 % RH) for a period of 9 d. Fresh artichoke bottoms were subjected to an edible coating of Cordia myxa gum (Cg) supplemented with or without calcium dichloride (CaCl2) 1 %, or ascorbic acid (AsA) 1 %. The key postharvest quality parameters which were investigated were weight loss, browning, polyphenol oxidase activity (PPO), firmness, vitamin C, and total phenolic compounds (TPC). Moreover, the microbial load of artichoke bottoms during the storage was also measured which comprised of total aerobic mesophilic and psychrotrophic bacteria, fungi, and E. coli. Results indicated that edible coating with Cg, when supplemented with CaCl2 or AsA, had a significant positive effect on weight loss, vitamin C, and TPC. Browning and PPO activities were significantly inhibited by Cg supplemented with AsA. The mesophilic and psychrotrophic bacterial count was significantly reduced in the presence of CaCl2 with or without Cg. For moulds and E. coli control, again Cg in combination with CaCl2 seems to be the most effective treatment. Hence, based on these findings, it can be recommended that postharvest coating Cg supplemented with CaCl2 could be a new application for delaying browning and extending the shelf-life of artichoke bottoms during refrigerated storage. Further research and development are required in commercial settings to test and scale the application of Cg in fresh-cut artichoke bottom industry

Modifying the design of pond production systems can improve the health and welfare of farmed Nile tilapia, Oreochromis niloticus

Infected fish have been known to recover from mild illness when they are able to locate to warmer water. This study aimed to replicate this 'behavioural fever' effect in an aquaculture setting by artificially heating a section of a fish pond (thereby introducing a thermal gradient) and effectively modifying pond design. This was achieved through the construction of a 'greenhouse' type structure above a section of the pond. Over the length of the production cycle at three typical Nile tilapia (Oreochromis niloticus) farms, the study collected data on water quality and fish growth and at the end of the cycle, blood samples were taken and total production was recorded. At each farm, fish were divided into two identical ponds, one with a greenhouse covering 3% of the pond surface area and one without. Results showed that greenhouse was effective in warming the surface of the water immediately below it. Oxygen levels were also higher under the greenhouse than outside of it and higher than in the control pond. Fish reared in the greenhouse ponds tended to be larger than the control ponds and had improved physiological and immune status (i.e., better liver and kidney function, higher antioxidant activity and lysozyme count; p < 0.05). The results of this study suggest that low-cost interventions that introduce thermal gradients in aquaculture systems may hold promise for improving health and welfare status of farmed fish in developing countries

Modifying the design of pond production systems can improve the health and welfare of farmed Nile tilapia, Oreochromis niloticus

Infected fish have been known to recover from mild illness when they are able to locate to warmer water. This study aimed to replicate this 'behavioural fever' effect in an aquaculture setting by artificially heating a section of a fish pond (thereby introducing a thermal gradient) and effectively modifying pond design. This was achieved through the construction of a 'greenhouse' type structure above a section of the pond. Over the length of the production cycle at three typical Nile tilapia (Oreochromis niloticus) farms, the study collected data on water quality and fish growth and at the end of the cycle, blood samples were taken and total production was recorded. At each farm, fish were divided into two identical ponds, one with a greenhouse covering 3% of the pond surface area and one without. Results showed that greenhouse was effective in warming the surface of the water immediately below it. Oxygen levels were also higher under the greenhouse than outside of it and higher than in the control pond. Fish reared in the greenhouse ponds tended to be larger than the control ponds and had improved physiological and immune status (i.e., better liver and kidney function, higher antioxidant activity and lysozyme count; p < 0.05). The results of this study suggest that low-cost interventions that introduce thermal gradients in aquaculture systems may hold promise for improving health and welfare status of farmed fish in developing countries.Article Information Received 26 September 2022 Revised 05 November 2022 Accepted 28 November 2022; O n l i n e F i r s t A r t i c l

Valorization of whey proteins and beetroot peels to develop a functional beverage high in proteins and antioxidants

IntroductionAdequate protein and antioxidant intake are crucial for everyone, particularly athletes, to promote muscle performance and prevent muscle damage. Whey proteins are high-quality proteins with high digestibility and bioavailability; beetroot peels are an abundant antioxidant source.MethodsThe present study was designated to develop a functional beverage based on mixing whey protein isolate (5%) with different concentrations of beetroot peel water extract (1, 2.5, and 5%) and flavored with strawberries puree (5%). In addition, we examined the stability of the physicochemical parameters and the bioactive components of the beverages during cold storage (4°C) for 14 days.Results and discussionWhey protein isolates enriched the juices with stable protein content during the storage (4.65–4.69%). Besides, the extract revealed a concentration-dependent effect on the bioactive components, the antioxidant activity, and the microbial load of the juices; it distinguished the fresh juices by high betalains and nitrate content, 87.31–106.44 mg/L and 94.29–112.59 mg/L, respectively. Beverages with 2.5% peel extract (T2) had the preferable sensory attributes compared to control and other treatments. On day 0, phenolics and flavonoids increased in T2 by 44 and 31% compared to the control, which elevated the scavenging activity of the juice (T2) (P &lt; 0.05). At the end of the storage period (14 days), phenolics and flavonoids of T2 recorded their lowest values, 26.23 and 21.75 mg/mL, respectively. However, they stood higher than phenolics (22.21 mg/mL) (p &lt; 0.05) and flavonoids (18.36 mg/mL) (p &gt; 0.05) of control. Similarly, betalains degraded by 45% to reach 47.46 mg/L in T2, which reduced the redness (a*) and increased the yellowness (b*) values.ConclusionConsequently, whey/strawberry/beetroot peel (5: 5: 2.5 w/v/w) in d.H2O is a functional beverage that provides the body with a high-quality protein and a considerable amount of antioxidants

Osteogenic Differentiation Potential of Human Bone Marrow and Amniotic Fluid-Derived Mesenchymal Stem Cells in Vitro & in Vivo

BACKGROUND: Cell therapies offer a promising potential in promoting bone regeneration. Stem cell therapy presents attractive care modality in treating degenerative conditions or tissue injuries. The rationale behind this is both the expansion potential of stem cells into a large cell population size and its differentiation abilities into a wide variety of tissue types, when given the proper stimuli. A progenitor stem cell is a promising source of cell therapy in regenerative medicine and bone tissue engineering. AIM: This study aimed to compare the osteogenic differentiation and regenerative potentials of human mesenchymal stem cells derived from human bone marrow (hBM-MSCs) or amniotic fluid (hAF-MSCs), both in vitro and in vivo studies. SUBJECTS AND METHODS: Human MSCs, used in this study, were successfully isolated from two human sources; the bone marrow (BM) and amniotic fluid (AF) collected at the gestational ages of second or third trimesters. RESULTS: The stem cells derived from amniotic fluid seemed to be the most promising type of progenitor cells for clinical applications. In a pre-clinical experiment, attempting to explore the therapeutic application of MSCs in bone regeneration, Rat lumbar spines defects were surgically created and treated with undifferentiated and osteogenically differentiated MSCs, derived from BM and second trimester AF. Cells were loaded on gel-foam scaffolds, inserted and fixed in the area of the surgical defect. X-Ray radiography follows up, and histopathological analysis was done three-four months post- operation. The transplantation of AF-MSCs or BM-MSCs into induced bony defects showed promising results. The AF-MSCs are offering a better healing effect increasing the likelihood of achieving successful spinal fusion. Some bone changes were observed in rats transplanted with osteoblasts differentiated cells but not in rats transplanted with undifferentiated MSCs. Longer observational periods are required to evaluate a true bone formation. The findings of this study suggested that the different sources; hBM-MSCs or hAF-MSCs exhibited remarkably different signature regarding the cell morphology, proliferation capacity and osteogenic differentiation potential CONCLUSIONS: AF-MSCs have a better performance in vivo bone healing than that of BM-MSCs. Hence, AF derived MSCs is highly recommended as an alternative source to BM-MSCs in bone regeneration and spine fusion surgeries. Moreover, the usage of gel-foam as a scaffold proved as an efficient cell carrier that showed bio-compatibility with cells, bio-degradability and osteoinductivity in vivo

Surveillance on A/H5N1 virus in domestic poultry and wild birds in Egypt

The endemic H5N1 high pathogenicity avian influenza virus (A/H5N1) in poultry in Egypt continues to cause heavy losses in poultry and poses a significant threat to human health. Here we describe results of A/H5N1 surveillance in domestic poultry in 2009 and wild birds in 2009-2010. Tracheal and cloacal swabs were collected from domestic poultry from 22024 commercial farms, 1435 backyards and 944 live bird markets (LBMs) as well as from 1297 wild birds representing 28 different types of migratory birds. Viral RNA was extracted from a mix of tracheal and cloacal swabs media. Matrix gene of avian influenza type A virus was detected using specific real-time reverse-transcription polymerase chain reaction (RT-qPCR) and positive samples were tested by RT- qPCR for simultaneous detection of the H5 and N1 genes. In this surveillance, A/H5N1 was detected from 0.1% (n = 23/) of examined commercial poultry farms, 10.5% (n = 151) of backyard birds and 11.4% (n = 108) of LBMs but no wild bird tested positive for A/H5N1. The virus was detected from domestic poultry year- round with higher incidence in the warmer months of summer and spring particularly in backyard birds. Outbreaks were recorded mostly in Lower Egypt where 95.7% (n = 22), 68.9% (n = 104) and 52.8% (n = 57) of positive commercial farms, backyards and LBMs were detected, respectively. Higher prevalence (56%, n = 85) was reported in backyards that had mixed chickens and waterfowl together in the same vicinity and LBMs that had waterfowl (76%, n = 82). Our findings indicated broad circulation of the endemic A/H5N1 among poultry in 2009 in Egypt. In addition, the epidemiology of A/H5N1 has changed over time with outbreaks occurring in the warmer months of the year. Backyard waterfowl may play a role as a reservoir and/or source of A/H5N1 particularly in LBMs. The virus has been established in poultry in the Nile Delta where major metropolitan areas, dense human population and poultry stocks are concentrated. Continuous surveillance, tracing the source of live birds in the markets and integration of multifaceted strategies and global collaboration are needed to control the spread of the virus in Egypt