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In this work titanium dioxide (TiO2) band gap energy modification was performed, in order to increase its photocatalytic activity on the visible spectrum range of solar radiation. Europium (Eu) was incorporated on the surface of TiO2 at 0.2 wt% and 0.6 wt%, using impregnation method. The photocatalyst was characterized using X-ray diffraction (XRD), nitrogen physisorption (N2-physisorption), inductively coupled plasma optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDXS) and UV-Visible spectrophotometry (UV-Vis). The effect of Eu incorporation on TiO2 over photocatalytic degradation of pesticide methidathion (MD) in aqueous solution was also evaluated. Results revealed that for TiO2 modified with 0.2 wt% Eu, the band gap energy decreased from 3.30 to 3.10 eV. Solar light activation was enhanced, obtaining 64% degradation and 57% mineralization of methidathion with turnover frequency (TOF) of 713 h−1.

In the present study, several novel three-dimensional (3D) ZnO–BiVO4 composites were prepared using the hydrothermal method, and their ability to detect nitrogen dioxide (NO2) gas was assessed. The fabricated sensing materials were examined using X-ray diffraction, transmission electron microscopy, energy dispersive spectrometry, scanning electron microscopy, ultraviolet–visible spectrophotometry, X-ray photoelectron spectroscopy, and surface-area and porosity analysis. The sensing material assessments verified that 3D ZnO–BiVO4 was successfully prepared; the sensing data revealed that 3D ZnO–BiVO4 exhibited excellent sensing response (24.6) to 1-ppm NO2 at room temperature. The composites exhibited a fast response (28 s) and short recovery time (75 s) when detecting 1-ppm NO2; they also exhibited long-term stability (decline of approximately 7% after 30 days) and selectivity to 10-ppm NO2 gas. A reasonable NO2 gas sensing mechanism for 3D ZnO–BiVO4 heterojunction was also proposed in this paper.

The collidal bimentalic nanoparticles of ZnO-Ag were prepared by laser ablation technqiue. The sysenthized bimetalic nanoparticles were characterized by UV–Vis spectrophotometry, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectrometry (EDX), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and Photo-Luminescence (PL). These techniques confirmed the formation of the bimetalic nanocompiste and showed that the size distribution of the synthesized bimetallic nanoparticles varied from 30 to 130 nm. The anticancer activity was validated by measuring the cell cytotocicty by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide) test applying HCT-116 and HELA cancer cell line. The cell lines’ sensitivity was the highest at 10 µg/mL of ZnO-Ag composite. This indicates that the bimetallic composite ZnO-Ag prepared by laser ablation technique is suitable for cancer treatment.

This paper presents the in-situ generation of gold nanoparticles (AuNPs) by reducing chloroauric acid (HAuCl4·H2O) with low molecular weight hydroxypropyl methylcellulose (HPMC), and HPMC-AuNPs nanocomposites are developed via solution casting method. The generation of AuNPs was initially established by a swap in color from pale yellow to purple, and then by UV–Visible (UV–Vis) spectrophotometry with the surface plasmon resonance (SPR) band observed at λ = 550 nm. The functional groups accountable for the reduction of gold ions to neutral gold atoms were identified using Fourier transform infrared spectroscopy (FT-IR). The crystalline form of the AuNPs with FCC structure was shown by X-ray diffraction (XRD) studies. The size and shape evolution of the different shaped AuNPs are confirmed by the transmission electron microscopy (TEM) study which divulged the presence of triangular plate, hexagonal, quasi spherical, isosceles trapezoid and truncated triangular morphologies of the AuNPs with an average size of 12.5 nm.

Human serum albumin (HSA) is a very well-characterized protein, which has already been used for many biocompatible coatings. We hypothesized binding between HSA and magnetic iron oxide nanoparticles (MNPs) as well as HSA coating stability to be pH- and ionic strength-dependent. The impact of phosphate buffer on protein coating was studied at varying pH (6.0, 6.6, and 7.5) and ionic strengths (0.15 and 0.30 M NaCl) using different physicochemical methods. In addition, the stability of HSA coatings on MNPs was studied by means of UV/visible spectrophotometry, dynamic light scattering, and electron magnetic resonance. We used differential scanning calorimetry (DSC) to determine the differences in the change of enthalpies and denaturation temperatures of HSA in various buffer conditions and on the surface of the particles. The binding thermodynamics of HSA and MNPs were determined by isothermal titration calorimetry (ITC), and it was also dependent on pH and ionic strength. The stability of adsorbed layer on MNPs decreases with increasing pH [from weakly acidic (pH 6.0-6.6) to slightly alkaline (pH 7.5)], as well as with an increase of ionic strength. This study develops stable HSA coating on MNPs which might be applied to a wide range of biomedical applications.

Superfine CaLaAl1-xCrxO4 (x = 0.02, 0.05, 0.08, 0.10) red ceramic pigments have been prepared by solution combustion reaction and subsequent high-temperature calcination. All of the pigments were characterized by X-ray diffraction (XRD), Field scanning electron microscopy (FESEM), UV–Vis spectrophotometry, Laser particle size analyzer and CIE L*a*b* spectrophotometry. Moreover, the effects of the doping amount of Cr3+ ion, calcination temperature, salt assistance and synthetic routes on chromatic performance and particle size distributions of the pigments were also investigated. The results showed that CaLaAl1-xCrxO4 pigment particles prepared via solution combustion reaction and subsequent calcination were well-dispersed and uniform in size. With the increase of doping amount of Cr3+ ion, the brightness value L* of CaLaAl1-xCrxO4 pigments decreased obviously and the redness value a* increased gradually. When x = 0.08, it showed the best chromatic performance (L* = 39.37, a* = 21.33, b* = 13.99). In addition, the synthetic pigments possess excellent high temperature stability which is conducive to the application of ceramic pigments. Most importantly, the synthetic method of CaLaAl1-xCrxO4 red ceramic pigments is not only cheap in raw materials, but also easy to industrialize.

Background The pH value plays critical roles in many chemical and physiological processes and exploring a more effective and sensitive method for the detection of pH is great need. Methods A new “off-on” pH chemosensor, N,N-bis[(2-furan)-ethyl]-3,4,9,10-perylene tetracarboxylic diimide (FEPTD), was designed and synthesized by Schiff-base condensation reaction with 2-furaldehyde and perylene-3,4,9,10-tetracarboxylic acid dianhydriden as the starting materials. FEPTD as a fluorescent probe was used for highly detecting pH values on the basis of molecular fluorescence spectrophotometry with the excitation wavelength of 300 nm in EtOH/Buffer solutions. Meanwhile, FEPTD was also applied for the detection of H+ in test paper and cotton. Significant finds FEPTD exhibited excellent solubility and stability in EtOH/Buffer (V:V, 1:1) with obvious “off-on” fluorescence response towards pH changes due to photo-induced electron transfer (PET) processes. The linear response ranges of FEPTD for pH detection in acidic system are from 4.32 to 3.10 with pKa = 3.69. Moreover, FEPTD showed an evident naked-eye color changes, where pale pink solution of FEPTD turned deepened with the fluorescent color varying from colorless to brilliant yellow. 1H NMR titration and density function theory calculations proved the possible sensing mechanism. Finally, FEPTD was successfully applied for the detection of H+ in test paper and cotton.

In this research study, poly(methyl methacrylate) (PMMA) polymer was selected and irradiated with alpha particles at various times. The alterations in the structure, optical parameters, and electrical properties of PMMA polymer caused by alpha particles have been assessed using XRD, ultraviolet–visible (UV/Vis) spectrophotometry and dc electric circuit, respectively. The results showed halo peaks in the XRD patterns, which indicate the amorphous nature of this type of polymer. The UV/Vis spectra demonstrated that absorption increases while transmittance decreases with an increase in the exposure time. Use of PMMA polymer as alpha dosimeters using the UV/Vis spectroscopic technique was investigated. The optical energy-gap values decreased from 3.44 eV to 3.01 eV. Furthermore, the refractive index values of all studied samples increased. Increasing the alpha radiation time enhanced dc-conductivity as well.

The present work aimed to synthesize Zn0.95Ag0.05O (ZnAgO) nanoparticles using rosemary leaf extracts as a green chemistry method. The characterization of Ag-doped ZnO nanoparticles was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet–visible spectrophotometry (UV–visible). The XRD, FTIR, and UV–visible spectra confirmed the formation of the presence of hexagonal ZnAgO nanoparticles. FESEM micrograph shows that the nanoparticles have been distributed homogeneously and uniformly. The morphology of ZnAgO nanoparticles is quasi-spherical configuration. Also, the mean particle size is in the range of 22–40 nm. The photocatalytic degradation of methylene blue in the presence of Ag-doped ZnO nanoparticles is nearly 98.5% after exposing 100 min. The ultraviolet lamp was used as the light source for photocatalyst degradation. The disc diffusion method was chosen to study the antibacterial activity of as-synthesized ZnAgO nanoparticles. Antibacterial activity of Zn0.95Ag0.05O nanoparticles against Staphylococcus aureus and Escherichia coli revealed that the as-synthesized ZnAgO nanoparticles were efficient in inhibition of bacterial growth.

Statement of problem The optical properties of esthetic computer-aided design and computer-aided manufacturing (CAD-CAM) materials can change depending on the clinical situation. Studies that compare esthetic CAD-CAM materials based on their optical properties are lacking. Purpose The purpose of this in vitro study was to evaluate the optical properties of esthetic CAD-CAM specimens after ultraviolet (UV) aging based on the type and thickness of the material. Material and methods In total, 240 plate-shaped specimens (14×12×1 mm and 14×12×2 mm) of a nanohybrid composite resin (Tetric CAD), a fine-structure feldspathic ceramic (Vitablocs Mark II), 2 different glass-ceramics (IPS Empress CAD and IPS e.max CAD), a zirconia-reinforced lithium silicate glass-ceramic (Celtra Duo), a polymer-infiltrated ceramic network (Vita Enamic), and 2 different resin nanoceramics (Cerasmart and Lava Ultimate) were fabricated (n=15). The optical parameters were analyzed by spectrophotometry before and after UV aging. The brightness (L∗), red green (a∗), yellow-blue (b∗), chroma (Ch), and hue (h) were measured, and the color difference (ΔE00) values were calculated. The translucency parameter (TP), total transmittance (Tt), and contrast ratio (CR) were also determined. Statistical analyses were performed with 1-way ANOVA, the Tukey honestly significant difference post hoc test, independent- and paired-samples t tests, and 2-way ANOVA (α=.05). Results Significant interactions were observed for the aging process, material type, and thickness for all optical parameters (P Conclusions The optical properties of the CAD-CAM specimens were affected by the aging process, material type, and thickness, and the color stability was clinically applicable in all CAD-CAM materials except groups Lava Ultimate and Cerasmart(ΔE00

Tungsten bronze has attracted global attention for its applications in near-infrared (NIR)-shielding windows. Here, alkali metal tungsten bronze (MxWO3, M = one or two types of Li, Na, and K)-doped glasses are prepared by a simple melt-quenching method. Their structure and properties were characterized by XRD, Raman spectroscopy, XPS and UV–Vis–NIR spectrophotometry. The effects of M on their structure and the NIR shielding performance are investigated. The LiF sample has the best NIR shielding performance, but its visible transmittance is sacrificed due to its low quality. The glasses containing mixed Li+ and K+ cooperate to form a high-quality Li+/K+-codoped tungsten bronze, while the glasses containing mixed Li+ and Na+ compete for limited tungsten resources to form Li+- and Na+-doped tungsten bronzes separately. The research here is helpful for understanding the role of different alkali metal ions in bulk energy-saving glass and is hugely significant for the guidance of the future applications of energy-saving glass without films.

K0.5Na0.5NbO3 (KNN) particles were prepared by a solid–state method. X–ray diffraction, scanning electron microscopy, UV–visible spectrophotometry, and electrochemical impedance spectroscopy were used to study the structure, morphology, and properties of the samples. The obtained KNN is a ferroelectric material with orthorhombic perovskite structure at room temperature. The KNN particles can be used as piezo/photo–bicatalysts for degrading organic pollutants by utilizing vibrational and solar energy; the catalytic activity of the particles can be significantly improved owing to their polarization under an applied electric field. Poled KNN particles show a bicatalytic degradation ratio of rhodamine B (RhB) dye reaching 92% after 60 min. The results indicate that the KNN particles can be applied as attractive ferroelectric catalysts for organic pollutant degradation.

Despite the advantages of targeting the pulmonary route through Dry Powder Inhalers (DPIs), the efficient delivery of biologics to the lungs still presents a considerable challenge: the generation of a powder with adequate aerodynamic properties while preserving the integrity of the biologic. Hence, the particle engineering technology employed to meet this balance plays a pivotal role. The present work describes a proof-of-concept study to investigate the effect of spray drying (SD) outlet temperature (Tout), atomization flow rate (Rotatom) and feed flow rate (Ffeed) on powder properties such as particle morphology and aerodynamic performance but also on the enzyme activity and protein conformational stability of a trehalose:leucine spray-dried powder featuring Cu,Zn-superoxide dismutase (Cu,Zn-SOD). This enzyme, often implicated in a broad spectrum of oxidative stress related diseases, from cystic fibrosis to rheumatoid arthritis, was used as a model Active Pharmaceutical Ingredient (API). Morphology and aerodynamic performance of the SD powders were determined by scanning electron microscopy (SEM), focused ion beam – SEM, laser diffraction and Andersen Cascade Impaction. For each SD run, enzyme activity retention (EAR) was measured by spectrophotometry and the protein melting temperature by differential scanning fluorimetry. To further understand the interaction between input and output variables, a statistical analysis was performed using SIMCA v13.0.3.0 software. Cu,Zn-SOD:trehalose:leucine spray dried powders were successfully generated upon different processing conditions, displaying fine particle fractions of ≈60% and EAR ranging from 50–80% with no loss of protein conformational stability. This technology thus proved to be suitable to prepare Cu,Zn-SOD based DPI powders within the considered working ranges.

Summary Two non-aqueous titrimetric and one visible spectrophotometric methods were developed and validated for the determination of valganciclovir hydrochloride (VLGH) in pure drug and tablets. The titrimetric methods were carried out by titrating the VLGH solution in glacial acetic acid with acetous perchloric acid (HClO4) in the presence of mercuric acetate and the end point of this titration was being located either visually (method A) or potentiometrically (method B). The spectrophotometric method (method C) was based on the addition of p-dimethylaminobenzaldehyde (DMAB) solution to VLGH solution and the formed yellow condensation product was measured at 420 nm. In titrimetric procedures, both the methods A and B were applicable over the range of 4–20 mg VLGH, and the calculations were based on a 1:1 reaction stoichiometry (VLGH:HClO4). In a spectrophotometric method, Beer's law was valid in a concentration range of 5–50 μg/mL VLGH with the corresponding value of molar absorptivity of 4.43 × 103 L/mol cm for method C. The limits of detection (LOD) and quantification (LOQ) for method C were 0.3 and 0.92 μg/mL, respectively. The developed methods were successfully applied to the determination of VLGH in tablets, and the results were statistically compared with those of a reference method by applying Student's t-test and F-test. Further, the validity of the developed methods was confirmed by recovery studies via standard addition technique.

A simple process was developed for the fabrication of alginate biopolymer film embedded by thiourea-functionalized AuNPs (thiourea/AuNPs) for palladium(II) detection. A mixture of sodium alginate and HAuCl4 was prepared as the main matrix and the AuNPs were in situ synthesized in alkali media provided by borax. The AuNPs entrapped in the alginate network were functionalized by thiourea and fabricated as a transparent film. The characteristics of thiourea/AuNPs alginate biopolymer film were investigated by Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDX) and UV–vis spectrophotometry. The UV–vis absorption spectrum showed the maximum wavelength of thiourea/AuNPs was at 530 nm. The effect of various parameters such as pH and thiourea concentration on the sensing of palladium(II) ions was investigated. The prepared alginate biopolymer film showed good stability over the time. The calibration graph was linear in the range of 0.05−2.10 μg mL−1 with a detection limit of 0.038 μg mL−1. The relative standard deviation (n = 10) for 0.6 and 1.2 μg mL−1 of palladium(II) was 4.6% and 3.5%, respectively. The sensing system was successfully applied for the determination of palladium in walnut leaves, wastewater, dental amalgam, and ceramic capacitor samples.

Steatosis is the most important prognostic histologic feature in the setting of liver procurement. The currently utilized diagnostic methods, including gross evaluation and frozen section examination, have important shortcomings. Novel techniques that offer advantages over the current tools could be of significant practical utility. The aim of this study is to evaluate the accuracy of surface color spectrophotometry in the quantitative assessment of steatosis in a murine model of fatty liver. C57BL/6 mice were divided into a control group receiving normal chow (n = 19), and two steatosis groups receiving high-fat diets for up to 20 weeks—mild steatosis (n = 10) and moderate-to-severe steatosis (n = 19). Mouse liver surfaces were scanned with a hand-held spectrophotometer (CM-600D; Konica-Minolta, Osaka, Japan). Spectral reflectance data and color space values (L*a*b*, XYZ, L*c*h*, RBG, and CMYK) were correlated with histopathologic steatosis evaluation by visual estimate, digital image analysis (DIA), as well as biochemical tissue triglyceride measurement. Spectral reflectance and most color space values were very strongly correlated with histologic assessment of total steatosis, with the best predictor being % reflectance at 700 nm (r = 0.91 [0.88–0.94] for visual assessment, r = 0.92 [0.88–0.95] for DIA of H&E slides, r = 0.92 [0.87–0.95] for DIA of oil-red-O stains, and r = 0.78 [0.63–0.87] for biochemical tissue triglyceride measurement, p

The use of antioxidants such as curcumin (Cur) or quercetin (Que) in biomedical and biotechnological applications has been studied owing to their capability to prevent oxidative stress and inhibit free radicals. Using polyhydroxybutyrate (PHB) electrospun fibers is presented as a proper option to encapsulate curcumin and quercetin due to its biocompatibility and biodegradability characteristics. Electrospun fibers were obtained dissolving commercial PHB in chloroform:N,N-dimethylformamide (DMF) (4:1) at 7% m/V, and adding two different concentrations of antioxidant (Cur, and Que) 1%m/m, and 7% m/m. These polymeric solutions were electrospun at different conditions and the obtained fibers were characterized by scanning electron microscopy (SEM), thermogravimetric (TGA) analysis, and Fourier transform infrared spectroscopy (FT-IR). The curcumin and quercetin releases into phosphate buffer saline (PBS) at pH 7.4 were obtained in vitro and measured by spectrophotometry. Antioxidant activities were measured by spectrophotometry in a microplate reader using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Fibers obtained with different formulations presented a chemical composition in accordance with PHB according to FTIR spectra, the diameters fluctuate between 0.761 ± 0.123 and 1.803 ± 0.557 μm, with qualities over 0.95 according to their morphology, and the melting temperature resulted near 178 °C according to the bibliography. The crystallinity of fibers decreases while curcumin or quercetin concentration increases for the studied interval, indeed, quercetin showed a higher impact on the relative crystallinity of fibers. Antioxidant activity of active compounds is maintained after encapsulation in PHB electrospun fibers, and quercetin resulted in near four times antioxidant activity compared to curcumin according to DPPH analysis.

In this study, a blue-green pigment has been prepared by partially replace Co2+ and Cr3+ in CoCr2O4 spinel structure with Mg2+ and Al3+ using a gel casting method The gel precursor was calcined at various temperatures (900–1400 °C) to obtain Mg0.5Co0.5CrAlO4 spinel pigment. Combining the Rietveld refinement method of XRD and peak fitting of XPS high-resolution spectra, the relationships between the cation distributions (Co2+, Mg2+, Al3+, and Cr3+) in the tetrahedron and octahedron of the spinel structure and the calcination temperature were examined. In the octahedron, the contents of Co2+ and Al3+ decreased with increasing calcination temperature, and the Mg2+ and Cr3+ contents exhibited the opposite trend. The bond lengths of A-O and B–O change with increasing calcination temperature, thereby leading to a change in the unit cell. The optical performance of the pigments was investigated via UV–vis and CIE L*a*b* spectrophotometry, and the study shows that the blue-green hue of the pigment powder is caused by the absorption at υ3～υ8 (370 nm–640 nm) in the visible light region. The varied contents of Co2+ and Cr3+ in the spinel structure among calcination temperatures cause the absorption spectrum intensity change, thereby resulting in various blue-green tones. This study lays the foundations for subsequent investigations of colour modification in MgxCo1-xAlyCr2-yO4 spinel.

Drug-delivery technology is an effective way to promote drug absorption and efficacy. Mesoporous hollow silica material and small-molecule drug ibuprofen were used as a carrier model and as model drug, respectively. By quantum chemical calculation (density functional theory and frontier orbital theory), it was found that the content of geminal silanols on the material surface played a decisive role in the release of the different drugs. The rough hollow materials are easily adsorbed and have a large loading capacity, and so we fabricated a mesoporous hollow silica material (R-nCHMSNs) with a rough surface and rich geminal silanols by using hydroxyl-rich nanocellulose as a template. The content and types of hydroxyl groups on the material surface were studied by 29Si NMR. The loading and delivery of ibuprofen and lysozyme were studied in detail. Materials with rich geminal silanols exhibited excellent delivery properties for different drugs, which shows great potential and research value for drug delivery.

Objective To synthesize and characterize a novel resin-based dental material containing 3-aminopropyltriethoxysilane (APTES) surface-modified halloysite-clay nanotubes (HNTs) for long-term delivery of guest molecules. Methods The optimal concentrations of HNT (10, 15, 20 wt.%) and silane (0, 2, 4 vol.%sil) to be incorporated into the resin-based materials were determined (15 wt.%HNT, 4 vol.%sil) after assessment of the mechanical properties (DC%, degree of conversion; FS, flexural strength; FM, flexural modulus; and UTS, ultimate tensile strength). The HNTsil-powder was loaded with chlorhexidine (CHX) to evaluate the effect of the silanization on drug release. Resin-discs were prepared for the following groups: RES (resin), HNT (resin+15 wt.%HNT), HNTsil (resin+15 wt.%HNT silanized), HNT-CHX (resin+15 wt.%HNT loaded with chlorhexidine), HNTsil-CHX (resin+15 wt.%HNTsil-CHX), and 0.2 vol.%CHX (resin+0.2 vol.%CHX solution). Specimens were stored in water for 1, 3, 5, 10, and 15 days at 37 °C. Aliquots from each time point and the final 15-day specimens were evaluated for the zone of inhibition (ZOI) against Streptococcus mutans. CHX release was analyzed using spectrophotometry at absorbance of 300 nm. Data were statistically analyzed (α = 0.05). Results All materials presented similar DC%. Reduced FS but increased FM was detected for 20 wt.%HNT–4%APTES. Groups with 15 wt.% and 20 wt.%HNT with/without APTES presented higher values of UTS. Agar diffusion data indicates that the HNTsil-CHX had a greater ZOI than all other groups over 15 days. HNTsil-CHX had the highest absorbance for day 1 but presented similar values to other groups every time point after. Significance Silanization of nanotubes followed by encapsulation of chlorhexidine is a promising technique for long-term delivery of guest molecules.

Statement of problem During the selection of tooth color, subjective communication with the laboratory and an incorrect color registration technique can lead to a poor color match of a restoration to adjacent teeth and oral structures. Purpose The purpose of this cross-sectional study was to compare color registration and color matching in a young Chilean population with 3 different methods: visual with a shade guide, digital visual with a cross-polarized filter, and instrumental with a spectrophotometer. Material and methods A total of 60 young volunteers were selected for tooth color registration of the maxillary right central incisor by using 3 different methods. Tooth color registration was performed using the CIELab and ΔE coordinate system. Results Significant differences were detected between the coordinates recorded by the visual analog method in comparison with the other 2 methods. In contrast, no significant differences were found between the L∗ and b∗ coordinates of the spectrophotometer and the digital visual method with use of a cross-polarization filter. The ΔE obtained between the visual shade and spectrophotometer was 7.35, and the ΔE between the digital visual method with the use of a cross-polarization filter and the spectrophotometer was 6.12. Conclusions No statistically significant differences were observed in the digital image with the cross-polarization filter and the spectrophotometer in the L∗ and b∗ coordinate of the CIELab system. In contrast, the visual analog method led to large differences with the other methods under study. The ΔE of the digital visual method with the use of cross-polarization filters and the spectrophotometer was 6.2, considered as an acceptable color mismatch (

Combined chromatographic and spectral analysis was used to analyse V redox conversion in the aqueous solution in the presence of several biologicaly and environmentally important thiols: L-cysteine, thioacetic acid and ethanethiol. The L-cysteine proved to be most powerful reducens of V(V), followed with thioacetic acid and ethanethiol.

International audience; There is no comprehensive method for differentiating between fresh and frozen-thawed fish fillets. This is an ongoing problem, particularly in relation to regulations. In this study, we showed the relevance of using the properties of mitochondria to discriminate fresh fish fillets from frozen-thawed fish fillets. The use of red muscle fibres of Gilthead sea bream allowed us to leave mitochondria in their physiological environment and to avoid possible alterations of mitochondrial membranes during isolation steps. The impact of freezing on fillets was evaluated by measuring the permeability of fibres and mitochondrial membranes to nicotinamide adenine dinucleotide + hydrogen (NADH). NADH permeability of fresh fillet fibres stored at 4°C was compared to the permeability of fibres extracted from frozen-thawed fillets. Two approaches were used to measure permeability changes: a spectrophotometric method that measured consumption of NADH by complex I, and an oxygraphic approach that measured stimulation of O 2 consumption by NADH. Fibres from frozen-thawed fillets were more permeable to NADH and were less sensitive to the permeabilizer alamethicin. The 2 sensitivity of this method allowed us to clearly detect red muscle fibres from frozen-thawed fish versus fresh fish fillets.

A novel antimicrobial gel composed of κ-carrageenan (KC) and a cinnamon essential oil (CEO)/hydroxypropyl-β-cyclodextrin (HPCD) composite was developed. The CEO/HPCD composite was characterized by UV-visible spectrophotometry and Fourier-transform infrared spectroscopy (FT-IR), and the changes in the principal components of CEO upon encapsulation by HPCD were analyzed by gas chromatography-mass spectrometry (GC-MS). The physicochemical properties, release kinetics and antimicrobial activity of the fabricated gels were investigated. The hardness of the KC gels increased with composite concentration in the range of 1.0-3.0% (w/v) and thereafter decreased. A similar trend was observed for the gumminess and chewiness, whereas the gel springiness remained essentially constant. The CEO/HPCD composite also enhanced the fluidity of the system, and the syneresis was positively correlated with the composite concentration. The controlled release of CEO from the gels was affected by the relative humidity (RH) and CEO content. The Ritger-Peppas model indicated that the CEO release kinetics from the gels proceeded through a combination of diffusion and framework erosion. The KC gel containing 5% CEO/HPCD composite displayed effective antimicrobial activity, prolonging the shelf life of sliced bread by at least two days. The reported gels may have potential applications as a promising material for food preservation.

An environmentally safe, economically, fast, and green synthetic approach was presented in this work for the fabrication of Ag-NP, Co3O4-NP and different weight ratio of Ag/Co3O4-NC. The synthesized samples were characterized by Fourier-transform infrared spectroscopy (FT-IR) and UV–visible spectrophotometry, Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM) along with X-ray energy dispersive spectroscopy (EDAX), and X-ray diffraction (XRD). The catalytic behaviour of the synthesized samples toward the reduction reaction of 4-nitrophenol in the presence of NaBH4 was studied. It is indicated that the synthesized nanocomposites show a satisfactory catalytic activity. The catalytic reduction of p-NP to p-AP obeys first-order kinetics with rate constant in the following order (Ag-NP> (Ag/Co3O4-NC) −1:1 > 1:3 > 3:1> Co3O4). This may be attributed to the high dispersion of Ag-NP compared to cobalt oxide nanoparticles. The microbial activity of the samples was analyzed using seven species of pathogenic microorganisms; 1) two species belongs to Gram negative bacteria; Escherichia coli (E.coli), and Salmonella, 2)four species belongs to Gram positive bacteria Marsa, Listeria, Staphylococcus aureus (S. aureus), bacillus subtilis (B.subtilis), and 3) one pathogenic fungal species Candidia. The data show that all samples exhibited an excellent range of inhibition toward all tested pathogenic microorganisms.

The present work focuses on the study of the electrochemical behavior of printed circuit boards (PCBs) leaching solutions using glycine and copper recovery by electrodeposition from leachate solutions. The recovery is done in a minimum number of steps and under ambient conditions of temperature and pressure. Printed circuits boards (PCBs) were pulverized and sieved, which allowed to obtain a PCBs powder of particle size fraction ≤ 1 mm. X-ray fluorescence spectroscopy analysis was used for PCBs powder characterization before and after leaching. The copper leaching has been carried out from PCBs powder in the open air, under ambient conditions of temperature and pressure using a buffer solution of glycine. UV–Vis spectrophotometry and atomic absorption spectrophotometry were utilized to determine the efficiency of copper leaching. Cyclic sweep voltammetry and chronoamperometry were employed to obtain informations on the electrochemical behavior of metals in the leaching solutions and then compared to that of synthetic solutions containing Cu (II) ions. UV–Visible spectrophotometry was used to determine the nature of the formed complex. Electrodeposition technique was applied in order to recover copper in powder form. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to examine the surface morphology and chemical composition of electrodeposited copper. The leaching solutions show exactly the same electrochemical behavior as the synthetic cupric solutions with two reduction peaks and a single oxidation peak, which demonstrates the high selectivity of glycine for copper. The chronoamperometric results confirm those obtained by voltammetry. UV–Visible spectrophotometry showed that the complex formed is [Cu(Gly)2] for the synthetic solutions as well as for the leachate solutions. Selective copper leaching was achieved with an efficiency of 92.5%. The resulting leachate solution was used directly for copper electrodeposition allowing the recovery of metallic copper as a pure product.

In this study, the effect of long-term use drugs of cholesterol-lowering atorvastatin and simvastatin on the activity and molecular structure of pepsin as important gastric enzyme was investigated by various experimental and computational methods. Based on the results obtained from fluorescence experiments, both drugs can bond to pepsin and quench the fluorescence intensity of protein through the static quenching mechanism. Also analysis of the thermodynamic parameters of binding the drugs to pepsin showed that the main forces in the complex formation for both are hydrophobic interactions and van der Waals forces. The effects of the drugs on the enzymatic activity of pepsin were then investigated and results showed that in the presence of both drugs the catalytic activity of the enzyme was significantly increased in lower (0.3–0.6 mM) concentrations however about the atorvastatin, increasing the concentration (0.9 mM) decreased the protease activity of pepsin. Also as a result of the FTIR studies, it was found that binding of the drugs to protein did not significant alteration in the structure of the protein. In order to obtain the atomic details of drug-protein interactions, the computational calculations were performed. The results in good agreement with those obtained from the experimental for interaction; confirm that the drugs both are bind to a cleft near the active site of the protein without any change in the structure of pepsin. Overall from the results obtained in this study, it can be concluded that both simvastatin and atorvastatin can strongly bond to a location close to the active site of pepsin and the binding change the enzymatic activity of protein.

Cytochrome P450 55A3 (CYP55A3) is an enzyme with the catalytic activity of nitric oxide (NO) to nitrous oxide using NADH or NADPH as the electron donor. Herein CYP55A3 has been expressed in E. coli and purified by His-tag columns. The electrochemical and spectroscopic characteristic of CYP55A3 and its interaction with NO has been studied. The direct electrochemistry of Fe3+/Fe2+ redox peaks in CYP55A3 was realized on the pyrolitic graphite electrode with the redox potential of −475 mV in pH 7.0 phosphate buffer. With the addition of NO a ferric nitroxyl complex (Fe3+-NO) formed with a new reduction peak at −0.78 V. The reduction peak current increased with the concentration of NO and showed typical Michaelis-Menten kinetic characteristics with the apparent Michaelis constant Kmapp 9.78 μM. The binding constant K calculated to be 3.93 × 104 M by UV–vis method. The fluorescence emission spectra of iron porphyrin in CYP55A3 showed with the peak wavelength 633 nm, and its fluorescence intensity increased after binding with NO. The fluorescence analysis demonstrated that NADH can relay electrons to iron porphyrin and reduce NO. The reductive product of NO released and the iron porphyrin in CYP55A3 turned back to the original form.

In this study, a versatile method for the manufacturing of chitosan-grafted porous poly (L-lactic acid) (P-PLLA) nanofibrous membrane by using polydopamine (PDA) as an intermediate layer has been developed. P-PLLA fibreswere electrospun and collected as nano/micro fibrous membranes. Highly porous fibres could serve as a substrate for chitosan to adsorb heavy metal ions. Moreover, PDA was used to modify P-PLLA surface to increase the coatinguniformity and stability of chitosan. Due to the very high surface area of P-PLLA membranes and abundant amine groups of both PDA and chitosan, the fabricated membranes were utilized as adsorbent for removal of copper(Cu2+) ions from the wastewater. The adsorption capability of Cu2+ ions was examined with respect to the PDA polymerization times, pH, initial metal ion concentration and time. Finally, the equilibrium adsorption data of chitosan-grafted membranes fitted well with the Langmuir isotherm with the maximum adsorption capacity of 270.27 mg/g.

Zinc-nickel ferrite nanoparticles were synthesized using co-precipitation method and used to remove the chromium metal from the industrial wastewater. Before water treatment, the ferrite nanoparticles were characterized for their structure, morphology and size distribution using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Scherrer’s formula was used to calculate the particle size from characteristic XRD peaks. The large surface area, controlled size and well-defined structure of the synthesized Ni-ZnFe2O4 nanoparticles showed remarkable results for wastewater treatment. The characterized nanoparticles were distributed into the industrial wastewater under constant stirring for 20 min. The nanoparticles’ suspension was subjected to UV–VIS spectrophotometry for the study of photo-catalytic behavior of Ni-ZnFe2O4 nanoparticles. The effect of Ni-ZnFe2O4 was investigated under visible light irradiation. Zn doping in Ni-ZnFe2O4 showed remarkable effect on efficiency of Cr removal from wastewater.

Magnesium aluminate nanoparticles were prepared by the sol–gel autocombustion method using mixture of alanine and urea as a fuel. The sample was characterized using XRD, FE-SEM, EDS, and IR spectroscopy. XRD analysis confirmed the formation of single-phase spinel compound with average particle size of 28 nm estimated from FE-SEM analysis. IR spectrum revealed the stretching vibration of MA-O and MB-O bonds at 517 and 691 cm−1 respectively. The adsorption process of Congo Red dye on the spinel surface was studied under static conditions using UV–Vis spectrophotometry. The maximum equilibrium adsorption capacity obtained from the Langmuir model was calculated 24.5 mg∙g−1. In addition, the salicylic acid and mixture of polyaromatic hydrocarbons as polar and nonpolar compounds, respectively, were used to investigate the adsorption properties of MgAl2O4 by liquid chromatography (UFLC) analysis. The results suggest that the magnesium aluminate can be used as efficient adsorbent for anionic dyes and polar compounds due tothe presence of active centers on its surface.

Thrombin is an important enzyme that plays a pivotal role in the blood clotting pathways. An imbalance in the activity of this enzyme is clinically known to be associated with various diseases, such as thrombosis, inflammation, atherosclerosis, and haemophilia, suggesting the need to devise sensors for Thrombin detection. However, the majority of the fluorescence-based Thrombin assays rely on fluorescence labelling assays or Thrombin specific recognition biomolecules, such as, aptamers or antibody which requires sophisticated techniques and makes it very expensive. Herein, we report a simple, selective, sensitive and label-free fluorescence detection scheme for Thrombin which is based on the interaction between Thrombin and a fluorescent complex of Heparin with a molecular rotor dye, Thioflavin-T. The detection scheme exploits selective interaction between cationic Thrombin and anionic Heparin to modulate the monomer-aggregate equilibrium of the Thioflavin-T-Heparin system. Importantly, the present system offers a ratiometric response that has the ability for robust quantification of Thrombin concentration even in complex medium. The involvement of all commercially available components is a crucial advantage of this detection scheme. Further, the detection scheme also shows reasonable response in diluted serum matrix.

The aim of this study was to investigate the use of a PADC polymer film in dosimetric applications for UV radiation. Optical properties and optical constants have been characterized by means of UV/Vis spectrophotometry. Two modes of combined treatment were applied: a sequence of UV and thermal annealing and vice versa, as well as a separated treatment involving UV exposure only. The final results proved to be highly dependent on the order of the combined treatments. The absorption edges, refractive indices, attenuation coefficients, and optical conductivities proved to be highly affected by increasing the exposure dose up to 4.458 kJ/cm2 in the second combined mode (post-UV annealing), but in the case of the other modes did not show such behavior. The dosimetric properties of this PADC polymer show excellent potential for a unique estimation of UV exposure doses over the range 0.446 to 4.458 kJ/cm2 by using the second mode.

Synthesis of heterojunctions to improve the efficiency of photocatalyst and charge-transfer properties has been a major concern recently. A novel photocatalyst copper ferrite-bismuth oxide (CuFe2O4/Bi2O3) nanocomposite was synthesized with unique magnetic properties. In this nanocomposite catalyst, the nano-petals of bismuth oxide (Bi2O3) were entangled with CuFe2O4 particles via the ultra-sonication method. The structure of as-synthesized samples was investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), whereas the morphology and optical band gap was determined using field emission scanning electron microscopy (FESEM) and UV–Vis spectrophotometry. Comparative photocatalytic activity of copper ferrite and the nanocomposite was examined for the degradation of Methylene Blue (MB) dye. The superior performance of photocatalyst is attributed to the visible light sanitizer; CuFe2O4 could assist Bi2O3 to absorb more photons of incident light which promotes the production of photoexcited electron-hole pairs. Additionally, the catalyst could be recycled and separated from the dye without any loss of photocatalytic efficiency owing to good chemical stability as well as magnetic separation.

A straightforward wet chemical method has been applied for the fabrication of Yb2O3 nanoparticles (NPs) from ytterbium nitrate solution by using ammonium carbonate as precipitation agent. Effects of precursor molarity (0.1, 0.15 and 0.2 M), calcination temperature (800, 900 and 1000 °C) and time (2, 4 and 6 h) on average crystallite size (CS) of the NPs were statistically investigated by using Box-Behnken design. A simple and effective quadratic model was proposed for controlling the CS. The CS values were calculated by using Williamson Hall method (W-H) from X-Ray Diffraction (XRD) broadening data and found to be ranging between 13 and 26 nm. Agglomerated NPs morphologies and particle sizes were revealed by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). Fourier Transform Infrared (FTIR) spectrophotometry confirmed that as-received Yb2(CO3)3xH2O powders were successfully transformed into Yb2O3 NPs with calcination. High-Resolution Transmission Electron Microscopy (HRTEM) results verified the average CS values. ANOVA analyses revealed that linear and squared terms of the production parameters were significantly related to the CS whereas interaction terms were insignificant with the confidence level of 95% (R2 = 92.67%, R2-adj = 87.17%). The calcination temperature had the highest impact on the average CS followed by the time and precursor molarity. Increasing calcination parameters resulted in bigger crystallites whereas increasing precursor molarity exhibited a critical supersaturation value (0.15 M) from which the average CS was decreased. © 2020 We would like to thank Prof. Dr. Kursat KAZMANLI and Dr. Suleyman TEKMEN for their characterization studies and assistance in recording TEM images at Bayburt University Central Research Laboratuary. 2-s2.0-85089133581

There is growing demand for simple to operate, sensitive, on-site quantitative assays to investigate concentrations of drug molecules in pharmaceutical preparations for quality assurance. Here, we report on the development of two colorimetric analysis methods for the study the antibiotic doxycycline hyclate (DOX) and the nasal decongestant oxymetazoline hydrochloride (OXY), in solution as well as in their respective formulations. We compare a UV/vis spectrophotometry method with a color change recorded on a microfluidic paper-based analytical device (μPAD). Detection is based on the pharmaceutical compounds coupling with diazotized 4-aminoacetophenone (DAAP) under alkaline conditions to produce colored azo-dye products. These azo-compounds were monitored by absorbance at 425 nm for DOX and 521 nm for OXY, with linear calibration graphs in the concentration range of 0.5–35 mg L−1 (DOX) and 1.0–40 mg L−1 (OXY) and limits of detection of 0.24 mg L−1 (DOX) and 0.32 mg L−1 (OXY). For the μPAD method, color intensity was measured from photographs and a linear increase was observed at concentrations from above approximately 15 mg L−1 for both compounds and up to 35 mg L−1 for DOX and 40 mg L−1 for OXY. The developed methods were also applied to the formulated pharmaceuticals and no interference was found from the excipient. Thus, the paper-based device provides an inexpensive, simple alternative approach for use outside centralized laboratories with semi-quantitative capability.

Aqueous extracts of the fruit shell of Hymenaea stigonocarpa were tested as an eco-friendly corrosion inhibitor for mild steel in 0.5 mol L−1 H2SO4. Corrosion data were obtained from potentiodynamic polarization and electrochemical impedance experiments. Surface analysis was carried out by scanning electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectrophotometry. The steel corrosion rate decreased in the presence of the fruit shell extract. Inhibition efficiency reached a maximum of ~90%. Activation energy of the inhibited corrosion process increased 2.5 times compared with the uninhibited process. Organic molecules present in the plant extract were detected on the steel surface. The development of an inhibitor film was modeled by the Langmuir isotherm. The fruit shell extract acted as a corrosion inhibitor decreasing the rate of hydrogen evolution.

This study investigates the suitability of statistical techniques for evaluating the fluoride content and the groundwater quality from Robles Department (RD) and Banda Department (BD) in Santiago del Estero (Argentina). For the original statistical study, evaluation of nine parameters (fluoride, pH, conductivity, atmospheric and water temperature, total dissolved solids, chloride, hardness, and alkalinity) of 110 collected underground water samples from 23 dispersed rural areas was proposed. Groundwater samples were obtained by sampling taken from wells at different depths. Fluoride levels were determined by a standard colorimetric method in two seasonal periods, the dry (from April to September) and rainy (from October to March) period. The analytical results obtained for physicochemical parameters such as pH, total dissolved solids (TDS), and temperature does not reveal any notable difference between the rainy and dry seasons studied. In both seasons, the atmospheric temperature average was 22 ​°C. With respect to fluoride content, approximately 50% of the analysed groundwater samples exceeded the limit established by current legislation (1.0 ​mg/L), obtaining concentration levels in the range of 0.01–2.80 ​mg/L. This study demonstrates the usefulness of the univariate statistical method (quartiles calculation, interquartile range IQR), multivariate principal component analysis (PCA), and cluster analysis to establish a better understanding of the state of the contamination of the waters in the region studied.

The present research reported a new electrochemical biosensor based on ds-DNA/Eu3+ doped NiO/CPE to detect amsacrine. Therefore, UV–Vis spectrophotometry, docking, and differential pulse voltammetry (DPV) have been used to study the interactions between amsacrine and dsDNA. Then, experimental parameters affected DNA immobilization and interactions between amsacrine and ds-DNA have been optimized. Afterwards, guanine oxidation peak current of ds-DNA has been chosen as a signal to analyze amsacrine in a concentration ranging between 0.1 and 100.0 μM and finally, limit of detection (LOD) of 0.05 μM has been calculated at optimal condition. Ultimately, it was found that the suggested biosensor is able to determine amsacrine in human serum and urine samples successfully.

In this work we used UV–visible–NIR diffuse reflectance spectrophotometry with optic fibres (FORS) in order to point out differences between mediaeval and 19th–20th century champleve enamels previously analysed with X-ray fluorescence spectrometry (XRF). FORS spectra of enamels collected in diffuse reflectance mode made it possible to obtain information useful not only for identifying the colourants of the enamels, but also for evaluating the authenticity of the artworks. By means of pattern recognition techniques, it was possible to highlight relevant spectral features useful for the discrimination of objects, the authentication of which was previously verified by means of elemental analysis (XRF). The role of transition metal ions, mainly iron and manganese, in the reflectance spectrum, has been critically discussed. FORS proved to be a highly reproducible technique, capable of detecting the chromophores in a glass matrix in a non-invasive and rapid manner. A comparison with historically accurate reference glass and enamels, together with data from other analytical techniques, was essential for validating the method. Furthermore, once the FORS methodology was defined, the results obtained showed great accuracy and reliability.

Transformation of renewable biomass into value-added chemicals and biofuels has evolved to be a vital field of research in recent years. Accurate estimation of reducing sugars post pretreatment of lignocellulosic biomass has been very inconsistent. For a few decades, 3,5-dinitrosalicylic acid (DNS) assay has been widely employed for the estimation of reducing sugars derived from pretreatment of lignocellulosic biomass. This assay tests for the presence of free carbonyl group (C=O), the so-called reducing sugars. This involves the oxidation of the aldehyde functional group present to the corresponding acid while DNS is simultaneously reduced to 3-amino-5-nitrosalicylic acid under alkaline conditions. However, the presence of other active carbonyl groups can potentially also react with DNS leading to incorrect yields of reducing sugars. Therefore, a detailed study has been carried out to evaluate the influence of active carbonyl compounds like furfural and 5-hydroxymethylfurfural (5-HMF) in the overall estimation of reducing sugars (glucose, xylose and arabinose) by DNS assay. In addition to this, reducing sugars estimation in the presence of furans were also investigated, it reveals that reducing sugars estimation was found to be 68% higher than actual sugars. Therefore, current findings strongly indicate that the employment of DNS assay for quantifying the reducing sugars in the presence of furans is not appropriate.

The material of CuS/polyvinyl alcohol-chitosan (CuS/PVACS) was prepared with a novel synthesis analysis. The crystallinity, morphological characteristics, and photocatalytic performance of the nano-materials were investigated by X-ray diffraction, field emission scanning electron microscopy X-ray photoelectron, and UV–vis spectrophotometry. The band gap values (Eg) was found as 2.50, and 2.04 eV for CuS, and CuS/PVACS nano-catalyst, respectively. The photo-degradation amount of the malachite green solutions which were degraded by CuS/PVACS in the UV-irradiation in 60 min was above 96.51%. The antibacterial properties of the CuS/PVACS has been evaluated versus (G+/G-) bacteria. The results of antibacterial performance indicated that CuS/PVACS nanocomposites have bacteriostatic behavior versus Escherichia coli, Pseudomonas syringae, Staphylococcus aureus and Streptococcus pneumoniae.

The objective of this study was to examine the thiol-disulfide profile tests in patients suffering from burn injuries.This case-control study comprised 48 patients with thermal burn injuries and 61 healthy individuals. Thiol-disulfide tests were conducted in both groups, and also, the changes of thiol-disulfide parameters were analyzed at zero time and on days 3, 7, 15, and 30 of the admission in patients with burn injuries.The patients had significantly decreased native and total thiol levels and native thiol/total thiol ratios, and significantly increased disulfide/native thiol and disulfide/total thiol ratios compared to control individuals (p0.001 for all). The variations of native thiol levels, total thiol levels, and disulfide/native thiol ratios were significantly different over time in patients with burn injuries (p0.001, p0.001, p0.05, respectively). There were strong associations with the clinical parameters and thiol-disulfide profile tests (p0.05 for all).There was a metabolic disturbance of the thiol-disulfide system among patients with burn injuries. The courses of thiol-disulfide variables in time overlapped with the burn mechanism. Strong associations provide that thiol-disulfide homeostasis might be a notable key for evaluating the severity of burns and predicting the survival.

A gilsonite from Qingchuan (Sichuan province, China) was separated into several fractions and characterized by various techniques. The vanadyl porphyrins were determined by inductively coupled plasma optical emission spectrometer, ultraviolet-visible spectrophotometry, high-temperature gas chromatography-atomic emission detector, and positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The results show that the gilsonite contains a large amount of metal elements, especially the vanadium content is as high as 3888 μg/g. A large number of vanadyl porphyrins are detected, in which the deoxophylloerythroetio porphyrins are the most abundant, indicating high molecular condensation but low thermal maturity. The huge reserves and high metal content imply important utilization value for this natural source.

Radiation dermatitis represents one of the most frequent side effects in breast cancer patients undergoing adjuvant whole-breast irradiation (WBI). Whether hypofractionated WBI induces comparable or less acute radiation-induced skin reactions than conventional WBI is still not fully clarified, as randomized evidence and objective assessments are limited. The aim of this study was to objectively determine frequency and severity of acute radiation-induced skin reactions during hypofractionated vs. conventionally fractionated adjuvant WBI.In this randomized multicenter study, a total of 140 breast cancer patients underwent either hypofractionated or conventional WBI following breast-preserving surgery. Maximum radiation dermatitis severity was assessed at completion and during follow-up by physician-assessed CTCAE v4.03 and the patient-reported RISRAS scale. Additionally, photospectrometric skin readings were performed to objectify skin color differences between both treatment arms.Radiation dermatitis severity was significantly lower in patients receiving hypofractionation compared with conventional fractionation (mean 1.05 vs. 1.43, p = .024). Grade 0 radiation dermatitis occurred in 21.43% vs. 4.28%, grade ≥2 in 27.14% vs. 42.91% and grade ≥3 in 0% vs. 4.34% of patients following hypofractionated and conventional WBI, respectively. Objective photospectrometric measurements (n = 4200) showed both decreased erythema severity (p = .008) and hyperpigmentation (p = .002) in the hypofractionation arm. Patients allocated to hypofractionated WBI also reported less pain (p = .006), less hyperpigmentation (p = 0.001) and less limitations of day-to-day activities (p = 0.001).Physician and patient-assessed toxicity scorings as well as objective photospectrometric skin measurements revealed that hypofractionated WBI yielded lower rates and severity of acute radiation-induced skin toxicity.

Polygalacturonase (PG) activity in plants can serve as an important index for plant disease. However, the conventional method to detect PG activity is a complex process and requires a skilled technician and expensive analytical equipment. In this study, a paper-based colorimetric sensor was developed based on the principle of the ruthenium red (RR) dye method for easy and simple measurement of PG activity. The proposed paper-based sensor has a three-layer structure for detection of PG activity in samples. The sensor sensitivity was enhanced by optimizing the pH of the sodium acetate buffer used in polygalacturonic acid (PGA)-RR complex formation and the reaction temperature for PG and the PGA-RR complex. Further, for quantitative analysis of PG activity, Delta RGB analysis was conducted to detect color changes in the sensing window of the sensor. Results presented that the linear measurement range of the paper sensor was 0.02-0.1 unit with the limit of detection of 0.02 unit, which showed a similar detection range, but a lower detection limit, compared to the spectrophotometry. Furthermore, PG activity based on culture condition was measured using samples from Sclerotium cepivorum to verify the potential application of the developed paper-based sensor in the field. The measured activity showed no statistically significant difference from the values obtained from the spectrophotometry at 95% confidence level. Therefore, the paper-based colorimetric sensor can be used to predict plant diseases in Allium crops during the stage of pathogen invasion, potentially contributing to the improvement of crop production.

Rapid and simultaneous in situ detection of multi-components is extremely crucial for the real-time monitoring of nutrients in fruits. Herein, a facile and user-friendly poly(carboxybetaine methacrylate)-coated paper-based microfluidic device (pCBMA-μPAD) has been exploited to synchronously identify and semi-quantify vitamin C, glucose, sucrose and fructose in fruits. The pCBMA was successfully grafted from the surface of paper sensor using a convenient and robust method, which was confirmed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectrometry (XPS). The superior hydrophilicity and ultra-low fouling of pCBMA endowed the pCBMA-μPAD with remarkably rapid response (3 min), high sensitivity, good linear relationship and low detection limit (LOD) (vitamin C: y = 33.809 + 5.175x, R2 = 0.993, LOD = 0.179 mmol/L; glucose: y = −0.113 + 30.066lg(x), R2 = 0.988, LOD = 0.095 mmol/L; sucrose: y = −5.334 + 34.858lg(x), R2 = 0.996, LOD = 0.097 mmol/L; fructose: y = 4.996 + 23.325lg(x), R2 = 0.994, LOD = 0.140 mmol/L). Furthermore, satisfactory results were yielded in the detection of these nutrients in 9 fruits, which were much agreed well with those obtained by spectrophotometry. Such a portable and versatile pCBMA-μPAD will profoundly shape the future of food analysis, especially for the assessment of food quality and nutrition in the process of agricultural production and marketing.

In the present work, a simple approach for colorimetric determination of allopurinol and its major metabolite oxypurinol is presented using gold nanoparticles as a probe. Gold nanoparticles were synthesized using the citrate reduction method and then functionalized using melamine (mel-AuNPs). The nanoparticles were characterized using UV–vis spectrophotometry, dynamic light scattering and transmission electron microscopy. The bare AuNPs capped with citrate anions (cit-AuNPs) gave a linear response towards allopurinol and oxypurinol within the range 0.20–40.0 μM and 0.25–25.0 μM respectively; however the melamine functionality on the AuNPs exhibited specific response for oxypurinol from 0.10 to 15.0 μM. This enabled development of a simple approach for the quantitation of the metabolite using mel-AuNPs, while the quantitation of allopurinol was carried out using the regression parameters of cit-AuNPs and the calculated amount of metabolite. For method optimization parameters such as the pH, incubation time and effect of ionic strength of the medium which can cause aggregation of nanoparticles were studied. The methodology was found to yield reliable results as evident from the validation results. The application of the method is demonstrated by analyzing allopurinol from tablet formulations and the drug and its metabolite from spiked plasma samples.

Simple and rapid spectrophotometric methods are described for determination of two mixtures of tamsulosin (TM), as minor component, with either solifenacin (SL) or tolterodine (TL). The proposed methods involve treatment of the absorbance ratio spectra or zero order spectra by derivative or discrete Fourier function. TM and TL mixture could not be resolved by manipulation of their zero order spectra due to the strong overlap between both spectra and only derivative or Fourier function coefficients of ratio spectra could resolve their spectra. TM and SL mixture was fully resolved by the manipulation of both ratio and zero order spectra. The values of the derivative or the Fourier function coefficients of ratio spectra and/or zero order spectra, at either peak or trough points, were correlated to the concentration of each drug in each mixture. Calibration graphs were linear in ranges 2.5-40 and 30-500 μg.mL−1 using derivative ratio and Fourier function ratio, 5-40 and 80–600 μg.mL−1 using direct derivative and 2.5–40 and 30–300 μg.mL−1 using direct Fourier function for TM and SL, respectively. The plots of derivative ratio amplitude and the Fourier function ratio coefficient versus concentration were linear over ranges 2.5–20 and 25–250 μg.mL−1 for TM and TL, respectively. Higher sensitivity as indicated by lower values of detection and quantitation limits were obtained using Fourier convoluted spectra (ratio or zero order) compared to derivative methods. All validation aspects per ICH guidelines are included. The proposed methods were also applied for the studied drugs assay in their tablets and capsules.

Cyanide (both HCN and CN- are represented by CN) has multiple industrial applications, is commonly found in some foods, and is a component of fire smoke. Upon exposure, CN blocks production of adenosine triphosphate, causing cellular hypoxia and cytotoxic anoxia, which can eventually result in death. Considering CN's quick onset of action and the long analysis times associated with current techniques, the objective of this study was to develop and validate a rapid and field-portable sensor to detect blood CN concentrations focusing on both concentration and diagnostic accuracy. The sensor takes advantage of the chemical properties of CN by converting it exclusively to HCN via acidification of whole blood. High-speed headspace transfer is used to deliver HCN to a capture solution where it is reacted with naphthalene dialdehyde and taurine to produce a fluorescent β-isoindole product. Simple spectrofluorometric analysis of the product provides quantitative analysis of CN from whole blood in 60s and requires only 25μL of blood (obtainable via fingerstick). A limit of detection of 5μM, a linear range of 10-200μM (with ≥15μM considered CN exposed), and excellent accuracy (100±15%) and precision (≤15.2% relative standard deviation) were obtained. To evaluate the diagnostic accuracy of the sensor, rabbit blood samples (N=190, including 24 blinded samples) were analyzed by both the sensor and a lab-based spectrophotometric method. An excellent positive correlation was obtained between the sensor and the lab-based method (R2 ˃ 0.995) confirming the concentration accuracy of the CN sensor. Moreover, the sensor produced no false positives or negatives when diagnosing CN poisoning.