Digital image determination of copper in food and water after preconcentration and magnetic tip separation for in-cavity desorption/color development.

A new analytical method for measuring copper in food and water was developed and validated, employing a solid-phase extraction (SPE) technique combined with digital-image-based (DIB) detection. A novel magnetic adsorbent of zinc ferrite/Citrullus colocynthis biochar (ZF@C.BC) was used to preconcentrate copper. A magnetic tip was used to separate the copper-loaded adsorbent from the extraction medium and to dispense it to the DIB plate. In-situ desorption and development of the spot color with iodide-starch reagent were carried out, and a digital image of the developed spots was captured using a smartphone and processed using ImageJ software. The copper adsorption capacity was 91.3 mg g-1. Desorption was effected using a 0.3 mol L-1 hydrochloric acid. The preconcentration factor was 300, the limit of detection was 4.8 µg L-1, the linearity was 16-600 µg L-1 and the sample throughput was 12 h-1. The developed approach was validated by analyzing food and water samples, confirming recoveries ≥ 91 % and 88 %, respectively, with RSD ≤ 8.4 %, n = 3.

Molybdenum Carbide/Ni Nanoparticles Embedded into Carbon Nanofibers as an Effective Non-Precious Catalyst for Green Hydrogen Production from Methanol Electrooxidation.

Molybdenum carbide co-catalyst and carbon nanofiber matrix are suggested to improve the nickel activity toward methanol electrooxidation process. The proposed electrocatalyst has been synthesized by calcination electrospun nanofiber mats composed of molybdenum chloride, nickel acetate, and poly (vinyl alcohol) under vacuum at elevated temperatures. The fabricated catalyst has been characterized using XRD, SEM, and TEM analysis. The electrochemical measurements demonstrated that the fabricated composite acquired specific activity for methanol electrooxidation when molybdenum content and calcination temperature were tuned. In terms of the current density, the highest performance is attributed to the nanofibers obtained from electrospun solution having 5% molybdenum precursor compared to nickel acetate as a current density of 107 mA/cm2 was generated. The process operating parameters have been optimized and expressed mathematically using the Taguchi robust design method. Experimental design has been employed in investigating the key operating parameters of methanol electrooxidation reaction to obtain the highest oxidation current density peak. The main effective operating parameters of the methanol oxidation reaction are Mo content in the electrocatalyst, methanol concentration, and reaction temperature. Employing Taguchi's robust design helped to capture the optimum conditions yielding the maximum current density. The calculations revealed that the optimum parameters are as follows: Mo content, 5 wt.%; methanol concentration, 2.65 M; and reaction temperature, 50 °C. A mathematical model has been statistically derived to describe the experimental data adequately with an R2 value of 0. 979. The optimization process indicated that the maximum current density can be identified statistically at 5% Mo, 2.0 M methanol concentration, and 45 °C operating temperature.

Recent advances in Metal-Organic Frameworks as nanocarriers for triggered release of anticancer drugs: Brief history, biomedical applications, challenges and future perspective.

Metal-Organic Frameworks (MOFs) have emerged as a promising biomedical material due to its unique features such as high surface area, pore volume, variable pore size, flexible functional groups, and excellent efficiency for drug loading. In this review, we explored the use of novel and smart metal organic frameworks as drug delivery vehicles to discover a safer and more controlled mode of drug release aiming to minimize their side effects. Here, we systematically discussed the background of MOFs following a thorough review on structural and physical properties of MOFs, their synthesis techniques, and the important characteristics to establish a strong foundation for future research. Furthermore, the current status on the potential applications of MOF-based stimuli-responsive drug delivery systems, including pH-, ion-, temperature-, light-, and multiple responsive systems for the delivery of anticancer drugs has also been presented. Lastly, we discuss the prospects and challenges in implementation of MOF-based materials in the drug delivery. Therefore, this review will help researchers working in the relevant fields to enhance their understanding of MOFs for encapsulation of various drugs as well as their stimuli responsive mechanism.

The potential use of urinary transferrin, urinary adiponectin, urinary Retinol Binding Protein, and serum zinc alpha 2 glycoprotein levels as novel biomarkers for early diagnosis of diabetic nephropathy: A case-control study.

BACKGROUND AND AIMS: The level of albuminuria is used to evaluate diabetic nephropathy (DN). However, to detect or predict the early stages of DN, better biomarkers are needed. METHODS: This study is a case-control observational study. 80 Egyptians participated in the study: 60 patients with type 2 diabetes mellitus (T2DM) were divided into three groups (20 patients each), and 20 healthy subjects with matched age and gender were used as controls. Demographic and laboratory data were analyzed. An enzyme-linked immunosorbent assay was used to determine the levels of four biomarkers of DN; urinary adiponectin (ADP), urinary transferrin, serum Zinc Alpha 2 Glycoprotein (ZAG), and urinary Retinol Binding Protein (RBP). RESULTS: The levels of DN biomarkers urinary ADP, transferrin, RBP, and serum, ZAG were significantly higher in patients with T2DM than in controls. The ROC curve of the validity of the simultaneous use of all four biomarkers in predicting albuminuria indicates a sensitivity of 90% and a specificity of 90%. The Area Under the Curve (AUC) was 0.948, the 95% confidence interval was 0.998-0.897, and the p-value was 0.001. CONCLUSIONS: In patients with T2DM, urine adiponectin, transferrin, RBP, and serum ZAG concentration may be useful biomarkers in the early diagnosis of DN. A further longitudinal prospective study is required to explore the potential utility of these biomarkers.

Photocatalytic demulsification of oil/water emulsions containing nonionic surfactant.

Separation of oil-water (OW) emulsions is investigated using a photocatalytic demulsification approach. Experiments were conducted using two types of photocatalysts, namely, ZnO and TiO2. The emulsion samples were prepared with oil to water ratios of 1:3, 1:1, and 3:1 and using nonionic surfactant Tween 20 as an emulsifier. The demulsification efficiency was determined using a direct time varying phase separation measurement, while dynamic light scattering (DLS) and microscope imaging (MI) were used to determine the change in emulsion droplets size. The investigation results showed that all the emulsions were destabilized and separated within 30-90 min with demulsification efficiency that ranged from 38 to 90%. On the other hand, untreated control samples remained stable with no phase separation for more than 24 h. For most of the studied experimental conditions, TiO2 nanoparticles gave better demulsification results than ZnO. Modeling of the batch demulsification kinetics for both systems agreed satisfactorily with the experimental measurements. This could allow its further extension towards design of continuous processes for potential implementation in treatment of industrial oily wastewaters.

Photocatalytic degradation of pharmaceutical micro-pollutants using ZnO.

This research paper presents the results of an experimental investigation of the degradation of three different contaminants including progesterone (PGS), ibuprofen (IBU), and naproxen (NAP) using ZnO as the photocatalyst and ultraviolet (UV) light as a source for catalysts activation. Two operating parameters, namely, catalyst loading and initial concentration of contaminants, were tested in a batch photocatalytic reactor. To demonstrate the large-scale applications, experiments were also conducted in a submerged membrane photocatalytic reactor. It has proven that ZnO photocatalyst degraded the three contaminants very efficiently under almost all the studied experimental conditions, with efficiency rates of 92.3, 94.5, and 98.7 % for PSG, IBU, and NAP, respectively. The photodegradation kinetics study was performed to calculate the reaction rate constant, which is found to follow pseudo-first order kinetics. The membrane photocatalytic reactor was efficient to remove pollutants and it is observed that the degradation rate increases with increasing the membrane oscillation frequency approaching that of the stirred reactor.

The Prognostic Value of Soluble Intercellular Adhesion Molecule 1 Plasma Level in Children With Acute Lung Injury.

OBJECTIVE: The objective of this study was to evaluate the prognostic significance of soluble intercellular adhesion molecule 1 (sICAM-1) measurement in plasma for the prediction of outcome of acute lung injury (ALI) in children that may allow early recognition of critical cases. METHODS: The study was performed as a prospective, controlled cohort study involving 40 children with ALI and 30 healthy children. The plasma level of sICAM-1 was measured at days 1 and 3 of development of ALI for the patient group and measured only once for the control group. C-Reactive protein was measured in both groups on day 1 only. RESULTS: There was significant increase in sICAM-1 in the patient group than in the control group ( P = .001*). The mortality rate reached 55% in children with ALI. The ceased group had significantly higher plasma sICAM-1 levels both at days 1 and 3 than the survived group ( P < .001*), and there was positive correlation between plasma sICAM-1 level and both duration of mechanical ventilation and the death rate, but more significant correlation was observed with plasma sICAM-1 levels at day 3 than day 1. CONCLUSION: Plasma sICAM-1 level served as a good predictor biomarker for both mechanical ventilation duration and the mortality risk in children with ALI.

Emulsification Characteristics Using a Dynamic Woven Metal Microscreen Membrane.

An oscillatory emulsification system for the production of oil in water emulsions using a commercially available low-cost woven metal microscreen (WMMS) is investigated. The system allows for independent control of both the oscillation frequencies and amplitudes such that it provides two degrees of freedom for controlling the emulsion properties. The investigations included the production of both surfactant and particle-stabilized emulsions. The average droplet size was found to decrease when both the oscillation frequency and amplitude was increased. For surfactant-stabilized emulsions, using bi-surfactants in both the continuous and dispersed phases resulted in a smaller droplet size due to lower interfacial tension. For particle-stabilized emulsions, both the hydrodynamics of the system and the hydrophobic and hydrophilic nature of the stabilizing particles influenced the interfacial properties at the oil-water interface, which in turn affected the final droplet size and distribution with potential droplet breakage. In absence of the latter, a simple torque balance model can be used to reasonably predict the average emulsion droplet size.

Bioactivity of Hybrid Polymeric Magnetic Nanoparticles and Their Applications in Drug Delivery.

BACKGROUND: Engineered magnetic nanoparticles (MNPs) possess unique properties and hold great potential in biomedicine and clinical applications. With their magnetic properties and their ability to work at cellular and molecular level, MNP have been applied both in-vitro and in-vivo in targeted drug delivery and imaging. Focusing on Iron Oxide Superparamagnetic nanoparticles (SPIONs), this paper elaborates on the recent advances in development of hybrid polymeric-magnetic nanoparticles. Their main applications in drug delivery include Chemotherapeutics, Hyperthermia treatment, Radio-therapeutics, Gene delivary, and Biotheraputics. Physiochemical properties such as size, shape, surface and magnetic properties are key factors in determining their behavior. Additionally tailoring SPIONs surface is often vital for desired cell targetting and improved efficiency. Polymer coating is specifically reviewed with brief discussion of SPIONs administration routes. Commonly used drug release models for describing release mechanisms and the nanotoxicity aspects are also discussed. METHODS: This review focus on superparamagnetic nanoparticles coated with different types of polymers starting with the key physiochemical features that dominate their behavior. The importance of surface modification is addressed. Subsequently, the major classes of polymer modified iron oxide nanoparticles is demonstrated according to their clinical use and application. Clinically approved nanoparticles are then addressed and the different routes of administration are mentioned. Lastly, mathematical models of drug release profile of the common used nanoparticles are addressed. RESULTS: MNPs emerging in recent medicine are remarkable for both imaging and therapeutics, particularly, as drug carriers for their great potential in targeted delivery and cancer treatment. Targeting ability and biocompatibility can be improved though surface coating which provides a mean to alter the surface features including physical characteristics and chemical functionality. The use of biocompatible polymers can prevent aggregation, increase colloidal stability, evades nanoparticles uptake by RES, and can provide a surface for conjugation of targeting ligands such as peptide and biomolecules with high affinity to target cells. CONCLUSION: Great efforts to bring MNPs from lab testing stage to clinic are needed to understand their physicochemical properties and how they behave in vivo, which resulted in few of them to exist in the market today. Although magnetic nanoparticles have not yet fully reached their optimal safety and efficiency due to the challenges they face in vivo, their shortcomings can be overcome through improvement of magnetictargeted carrier by pre-clinical trials and continuous studies.

Sacrificial hydrogen generation from aqueous triethanolamine with Eosin Y-sensitized Pt/TiO2 photocatalyst in UV, visible and solar light irradiation.

In this paper, we have studied Eosin Y-sensitized sacrificial hydrogen generation with triethanolamine as electron donor in UV, visible, and solar light irradiation. Aeroxide TiO2 was loaded with platinum metal via solar photo-deposition method to reduce the electron hole recombination process. Photocatalytic sacrificial hydrogen generation was influenced by several factors such as platinum loading (wt%) on TiO2, solution pH, Eosin Y to Pt/TiO2 mass ratio, triethanolamine concentration, and light (UV, visible and solar) intensities. Detailed reaction mechanisms in visible and solar light irradiation were established. Oxidation of triethanolamine and formaldehyde formation was correlated with hydrogen generation in both visible and solar lights. Hydrogen generation kinetics followed a Langmuir-type isotherm with reaction rate constant and adsorption constant of 6.77×10(-6) mol min(-1) and 14.45 M(-1), respectively. Sacrificial hydrogen generation and charge recombination processes were studied as a function of light intensities. Apparent quantum yields (QYs) were compared for UV, visible, and solar light at four different light intensities. Highest QYs were attained at lower light intensity because of trivial charge recombination. At 30 mW cm(-2) we achieved QYs of 10.82%, 12.23% and 11.33% in UV, visible and solar light respectively.

Resolution of sertraline with (R)-mandelic acid: chiral discrimination mechanism study.

The chiral discrimination mechanism in the resolution of sertraline with mandelic acid was investigated by examining the weak intermolecular interactions (such as hydrogen bond, CH/π, and van der Waals interactions) and molecular packing difference in crystal structures of the resulting diastereomeric salts. A new one-dimensional chain-like hydrogen-bonding network and unique supramolecular packing mode are disclosed. The investigation demonstrated that stable hydrogen-bonding pattern, herringbone-like arrangement of aromatic rings, and planar boundary surface in the hydrophobic region are the three most important structural characteristics expected in less soluble diastereomeric salts. The existence and magnitude of hydrogen bond, CH/π interaction, and van der Waals interaction related to three characteristic structures, determine the stability of diastereomeric salt. The hydrogen bond is not necessarily the dominant factor while the synergy and optimization of all weak intermolecular interactions attribute to the chiral recognition.

Chiral discrimination in diastereomeric salts of chlorine-substituted mandelic acid and phenylethylamine.

The crystal structures of diastereomeric salts of chloromandelic acid and phenylethylamine were determined and are presented herein. The structure comparison between less soluble salts and more soluble salts shows that weak interactions such as CH/pi interactions and van der Waals gain importance and contribute to chiral recognition when the hydrogen bonding patterns are very similar.

Identification and characterization of solid-state nature of 2-chloromandelic acid.

The racemate and enantiomers of 2-chloromandelic acid were characterized by SS-NMR, XRPD, and FTIR. The binary melting point phase diagram was constructed by DSC (differential scanning calorimetry). The solid-state nature of 2-chloromandelic acid was identified to be a racemic compound. The crystal structure of racemic compound was determined to be monoclinic P2(1)/c.

Investigation of a dual-particle liquid-solid circulating fluidized bed bioreactor for extractive fermentation of lactic acid.

A dual-particle liquid-solid circulating fluidized bed (DP-LSCFB) bioreactor has been constructed and investigated for the simultaneous production and extraction of lactic acid using immobilized Lactobacillus bulgaricus and ion-exchange resins. The apparatus consisted of a downer fluidized bed, 13 cm I.D. and 4.75 m tall, and a riser fluidized bed, 3.8 cm I.D. and 5.15 m in height. The lactic acid production and removal was carried out in the downer, while the riser was used for the recovery of lactic acid. A continuously recirculating bed of ion-exchange resin was used for adsorption of the produced acid as well as for maintaining optimum pH for bioconversion, thus eliminating the need for costly and complex chemical control approach used in conventional techniques. Studies using lactic acid aqueous solution as feed and sodium hydroxide solution as regeneration stream showed 93% lactic acid removal from the downer and 46% recovery in the riser under the conditions investigated. Such results prove the functionality of using the newly developed bioreactor design for the continuous production and recovery of products of biotechnological significance.

(R)-1-Phenyl-ethanaminium (S)-4-chloro-mandelate.

The absolute configuration of the title complex, C(8)H(12)N(+)·C(8)H(6)ClO(3) (-) or [R-C(6)H(5)C(H)CH(3)NH(3)][S-4-ClC(6)H(4)C(H)(OH)CO(2)], has been confirmed by the structure determination. In the crystal structure, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds form a two-dimensional network perpendicular to the c axis.