Efficacious elimination of crystal violet pollutant via photo-Fenton process based on Gd(2-x)La(x)Zr2O7 nanoparticles.

The photo-Fenton process is an appropriate method of the Advanced Oxidation Process that is used in the photocatalysis of organic dyes like crystal violet (CV). La3+ ion substituted gadolinium zirconium oxide Gd(2-x)La(x)Zr2O7 nanopowders (x = 0.1, 0.2, 0.3, and 0.5) have been successfully prepared by using sol-gel auto-combustion method to be used for the efficient photocatalysis of CV with photo-Fenton process. The well-crystallized defect-fluorite, structured with space group: Fm-3m, was detected using X-ray diffraction analysis. The lattice parameters were found to increase with the evaluated La3+ ion concentration. The grain size of the synthesized powders increased with the increase in La3+ ion content. The SAED patterns depicted fluorite structured fluorite. UV/Vis. spectrophotometer was used for the determination of band gap energy of Gd(2-x)La(x)Zr2O7 nanopowders which increased with increasing La3+ ion content. It was found to enhance from 4 to 3.6 eV. The visible spectrophotometer was used for determining unknown concentrations during the photocatalysis process to assure the effectiveness of the process. Overall, results illustrate that the photo-Fenton reaction on Gd(2-x)La(x)Zr2O7 performed excellently in removing crystal violet (CV). The photo-remediation ratio of CV reached 90% within 1 h.

Structural, optical, and cytotoxicity studies of laser irradiated ZnO doped borate bioactive glasses.

Borate glasses (BG) doped with different amounts of ZnO (0-0.6 mol%) were formed by the traditional melt quenching technique. The different glasses so made were characterized using different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and UV-Vis absorption optical properties. The XRD patterns showed an amorphous structure with one broad peak at 2θ = 29°, while the phonons bands were studied in terms of the FTIR bands. Optical properties of the glasses were studied using UV-Vis absorption spectra in the range 190-1100 nm, in which the prominent band lies at about 261.5 nm of peak position, from which the bandgab (Eg) was calculated from its edge using Tauc's plot, with Eg ~ 3.5 eV. The laser irradiation showed no significant changes in the absorption bands, despite a significant change observed in the amorphous behavior in the XRD pattern. The cell viability was performed for two samples of the BG and 0.6 mol% ZnO doped using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay method. The result showed better cell viability and low toxicity. So, ZnO doped BG can be used in various biomedical applications.

Blend biopolymeric nanofibrous scaffolds of cellulose acetate/ε-polycaprolactone containing metallic nanoparticles prepared by laser ablation for wound disinfection applications.

Laser ablation technique was utilized to synthesize versatile metallic nanoparticles including ZnO, Ag and CuO which were incorporated into the blend matrix of cellulose Acetate (CA) and ε-polycaprolactone (PCL) nanofibrous scaffold. The compositional, microstructural and morphological behaviors for the obtained nanofibers were investigated using X-ray diffraction (XRD), Fourier Transformed Infrared, Transmission Electron Microscope (TEM) and Field Emission-Scanning Electron Microscope (FESEM). The cell viability and antibacterial activity were investigated against Staphylococcus aureus (S. aureus) and Escherichia coli (E-coli). TEM micrographs refer that while CuONPs were involved in the middle of CA/PCL fibrous scaffold with diameters around 160 nm. The morphological investigations indicated the scaffolds were configured in a non-oriented form with diameters 0.45-0.9 µm in the case of ZnONPs involved in blend matrix fibers. The ratio of viable cells displays that compositions are biocompatible, while the antibacterial activity of both AgNPs and CuONPs showed an inhibition zone around 11.2.3 ± 2.2 mm and 9.4 ± 1.2 mm respectively. Bio-blend polymers matrices carrying nanoparticles could be tailored for a plethora of biomedical applications upon their compositions.

Optical and dielectric characteristics of polyethylene oxide/sodium alginate-modified gold nanocomposites.

Films of polyethylene oxide and sodium alginate polymer blend (50/50 wt%) embedded with different quantities of Au nanoparticles with size 3-32 nm were made using the casting process. The nanocomposite films were examined by XRD analysis, FT-IR spectroscopy, TEM, UV/vis spectroscopy, and AC conductivity and dielectric parameter measurements. The XRD spectra revealed the amorphous nature of the prepared films (PEO/SA-Au NPs). From the Fourier transform infrared spectra it can be seem that the intensity of the FT-IR bands decreased which depicted the existence of the interaction between (PEO/SA) virgin polymer and gold nanoparticles. The TEM micrographs showed a cubic-structure for Au NPs with an average size of 15-20 nm. The optical properties of the polymer composite were examined by ultraviolet-visible techniques. In a direct transition the optical energy gap (E g) of the prepared films is decreased from 4.73 to 2.92 eV and in an indirect transition decreased from 2.95 to 1.50 eV. The dielectric and electrical spectra of the obtained films were examined via dielectric broad-band spectroscopy. The electrical and dielectric measurements are appropriate for the use of the polymer nanocomposite films in the fabrication of electroactive materials.

Structural and optical absorption studies on Cr2O3 doped SrO-P2O5 glasses.

Cr2O3 doped glasses in the system xCr2O3-(60-x) P2O5-40SrO, where x = 0.0, 0.025, 0.05, 0.1, 0.2, 0.4 & 0.6 mol% were prepared and investigated by X-ray, UV-Vis, and FT infrared spectroscopy. According to the X-ray data, no sharp peaks can be observed, but only abroad halo which points the amorphous nature of the glass samples. Optical absorptions have shown that Cr ions are present in two possible oxidation states (trivalent & hexavalent). Increasing Cr2O3 concentrations in the glass network cause a reduction in the indirect and direct optical energy gap of prepared samples from 3.94-3.5 eV and 4.92-4.4 eV, respectively. This behavior is related to the network forming ability of Cr2O3. FTIR spectra of Cr2O3 containing glass showed some differences compared to base glass samples. In addition, calculated physical and optical parameters reveals a close similarity to base glass that can be correlated to the minor addition of Cr2O3.

Photodegradation of methylene blue with PVA/PVP blend under UV light irradiation.

Homogenous films of PVA/PVP blend (1:1) doped with different levels of methylene blue dye (MB) were prepared using the casting technique. The absorption spectra of doped PVA/PVP blend showed two absorption peaks due to the chromophor groups of MB while the pure PVA/PVP blend does not. The UV irradiation causes photodegradation of MB dye. The recovery of photodegraded MB is observed after keeping the sample 3h in atmospheric air. The value of the optical energy gap (Eg) decreases with increasing the doping levels with MB. The spectral distribution of absorption index (k) and refractive index (n) are determined from the reflection and transmission spectra in the spectral range 200-2500nm. The dependence of both n and k on wavelength of the incident light and the wt% content of MB in PVA/PVP blend is discussed. A normal dispersion observed at wavelength λ>370nm for pure PVA/PVP blend and λ>800nm for MB doped samples. The obtained results suggest the possible use of the studied system in many applications.

Removal and separation of Cu(II) from aqueous solutions using nano-silver chitosan/polyacrylamide membranes.

In the present study, adsorption of Cu(II) ions from aqueous solutions was evaluated using new thin adsorptive membranes modified with silver nanoparticles. Membranes were prepared from chitosan/polyacrylamide polymer blend. The variation of adsorption process was investigated in batch sorption mode. Infrared absorption spectra were applied for chemical characterization of the prepared polymer blend. Thermogravimetric analysis showed that addition of polyacrylamide to chitosan increased its thermal stability. The kinetics and thermodynamic parameters of Cu(II) ions adsorption onto the membranes were studied by removal experiments of Cu(II) ions from standard aqueous solutions. The kinetic data fitted to the traditional Lagergren adsorption kinetic equations. Thermodynamic studies indicated endothermic (ΔH°> 0) and spontaneous (ΔG°< 0) adsorption together with entropy generation (ΔS°> 0) at the solid/liquid interface process. Regeneration experiments showed that the newly prepared membranes could be reconditioned without significant loss of its initial properties even after three adsorption-desorption cycles. The results suggest that the prepared composite membranes can be efficiently applied for the adsorptive removal of Cu(II) ions from natural water samples. Antimicrobial activity was tested against two gram negatives, two gram positives and Candida sp. microbes and they showed a remarkable bioactivity indicating the capability of applying such membranes for a dual action.

Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives.

Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680cm(-1) after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content.

Influence of CuO content on the structure of lithium fluoroborate glasses: Spectral and gamma irradiation studies.

Glasses of lithium fluoroborate of the composition LiF 15%-B2O3 85% with increasing CuO as added dopant were prepared and characterized by combined optical and FTIR spectroscopy before and after gamma irradiation. The optical spectrum of the undoped glass reveals strong UV absorption with two distinct peaks at about 235 and 310 nm and with no visible bands. This strong UV absorption is related to the presence of unavoidable trace iron impurity (Fe(3+)) within the materials used for the preparation of this glass. After irradiation, the spectrum of the undoped glass shows a decrease of the intensity of the UV bands together with the resolution of an induced visible broad band centered at about 520 nm. The CuO doped glasses reveal the same UV absorption beside a very broad visible band centered at 780 nm and this band shows extension and splitting to several component peaks with higher CuO contents. Upon gamma irradiation, the spectra of all CuO-doped glasses reveal pronounced decrease of their intensities. The response of irradiation on the studied glasses is correlated with suggested photochemical reactions together with some shielding effect of the copper ions. The observed visible band is related to the presence of copper as distorted octahedral Cu(2+) ions. Infrared absorption spectra of the prepared glasses show repetitive characteristic triangular and tetrahedral borate units similar to that published from alkali or alkaline earth oxides B2O3 glasses. A suggested formation of (BO3/2F) tetrahedral units is advanced through action of LiF on B2O3 and these suggested units showing the same position and number as BO4 tetrahedra.

Effect of oxytocin and PGF2α on chlortetracycline absorption from the uterus of early postpartum camels (Camelus dromedarius).

Fifteen parturient camels given chlortetracycline (CTC) as intrauterine pessaries (3 g/head) were divided into the control group (n = 5), which remained untreated, oxytocin-treated group (50 IU, intramuscular; n = 5), and cloprostenol-treated group (Estrumate, 500 µg, intramuscular; n = 5). Serum samples were collected at 0, 1, 2, 4, 8, 24, 48, and 72 hours after treatment and CTC was determined. The CTC appeared in blood within 1 hour. The maximum concentration of CTC was detected in blood after 72 (543.58 ± 117.85 µg/L), 8 (520.48 ± 13.65 µg/L), and 1 hour (831.98 ± 111.01 µg/L) of administration in control, oxytocin-, and PGF2α-treated camels, respectively. There was a high significant effect of time (P < 0.001) and treatment-by-time interaction (P < 0.001) on serum CTC concentration. In the control group, there was a significant (P < 0.05) increase in CTC concentrations at 72 hours compared to the other times. In the oxytocin group, there was a significant (P < 0.05) decrease in CTC concentrations at 24, 48, and 72 hours compared to its level after 1 or 8 hours. In PGF2α, there was a significant (P < 0.001) decrease in CTC concentrations at 2, 4, 8, 24, 48, and 72 hours compared to its level after 1 hour. Treatment contrast at different time points showed a significant (P < 0.001) increase in CTC concentration after 1 hour in the PGF2α-treated group compared to oxytocin and control groups. By 72 hours, CTC concentrations were significantly (P < 0.05) lower in PGF2α and oxytocin groups than in the control group. In conclusion, serum CTC concentration in dromedary camels increases within 1 hour after intrauterine administration and remains elevated for at least 72 hours in control, oxytocin-, and PGF2α-treated animals.

Impact of vanadium ions in barium borate glass.

Combined optical and infrared spectral measurements of prepared barium borate glasses containing different concentrations of V2O5 were carried out. Vanadium containing glasses exhibit extended UV-visible (UV/Vis.) bands when compared with base binary borate glass. UV/Vis. spectrum shows the presence of an unsymmetrical strong UV broad band centered at 214 nm attributed to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of such glass. The calculated direct and indirect optical band gaps are found to decrease with increasing the vanadium content (2.9:137 for indirect and 3.99:2.01 for direct transition). This change was discussed in terms of structural changes in the glass network. Infrared absorption spectra of the glasses reveal the appearance of both triangular and tetrahedral borate units. Electron spin resonance analyses indicate the presence of unpaired species in sufficient quantity to be identified and to confirm the spectral data.

Effect of 3d-transition metal doping on the shielding behavior of barium borate glasses: a spectroscopic study.

UV-visible and FT infrared spectra were measured for prepared samples before and after gamma irradiation. Base undoped barium borate glass of the basic composition (BaO 40%-B2O3 60mol.%) reveals strong charge transfer UV absorption bands which are related to unavoidable trace iron impurities (Fe(3+)) within the chemical raw materials. 3d transition metal (TM)-doped glasses exhibit extra characteristic absorption bands due to each TM in its specific valence or coordinate state. The optical spectra show that TM ions favor generally the presence in the high valence or tetrahedral coordination state in barium borate host glass. Infrared absorption bands of all prepared glasses reveal the appearance of both triangular BO3 units and tetrahedral BO4 units within their characteristic vibrational modes and the TM-ions cause minor effects because of the low doping level introduced (0.2%). Gamma irradiation of the undoped barium borate glass increases the intensity of the UV absorption together with the generation of an induced broad visible band at about 580nm. These changes are correlated with suggested photochemical reactions of trace iron impurities together with the generation of positive hole center (BHC or OHC) within the visible region through generated electrons and positive holes during the irradiation process.

Optical and FT Infrared spectral studies of vanadium ions in cadmium borate glass and effects of gamma irradiation.

Combined optical and infrared absorption spectra of V2O5-doped cadmium borate glasses were investigated before and after gamma irradiation with a dose of 8 Mrad (=8×10(4) Gy). The undoped base cadmium borate glass reveals a spectrum consisting of strong charge transfer UV absorption bands which are related to the presence of unavoidable contaminated trace iron impurities (mainly Fe(3+)). The V2O5-doped glasses reveal an extra band at 380nm and the high V2O5-content glass also shows a further band at about 420nm. The observed optical spectrum indicates the presence of vanadium ions mainly in the pentavalent state (d(0) configuration). The surplus band at 420nm shows that some trivalent vanadium ions are identified at high V2O5 content. The optical spectra of the glasses after gamma irradiation show small decrease of the intensity of the UV absorption which are interpreted by assuming the transformation of some Fe(3+) ions by photochemical reactions with the presence of high content (45mol%) of heavy massive CdO causing some shielding behavior. FT infrared absorption spectra of the glasses show vibrational bands due to collective presence of triangular and tetrahedral borate groups in their specific wavenumbers. The FTIR spectra are observed to be slightly affected by both the V2O5-dopants being present in modifying low percent or gamma irradiation due to the presence of high content heavy CdO.

Impact of in situ preparation of CdS filled PVP nano-composite.

Cadmium sulfide nanoparticles filled polyvinyl pyrrolidone (PVP) were prepared by in situ wet chemical precipitation technique. X-ray diffraction (XRD), Fourier transforms infrared spectra (FTIR), transmission electron microscopy (TEM) and ultraviolet-visible (UV/Vis) were used to characterize the prepared nano-composites. Density Function Theory (DFT) was used to approve the complexation process. XRD results indicate appearance of two peaks at about 28.1°, 27.4° corresponds to (101) and (002) planes which suggest hexagonal phase of CdS with lattice constants of 4.14, 6.72 Å in the polymeric matrix. UV/Vis spectra reveal that nano-composite films show quantum confinement effect. The absorption showed a shift toward the shorter wavelength (blue shift) with decrease in the concentration of Cd+ ions. Optical band gap and particle size were calculated and is in agreement with the results obtained from TEM data. Transmission electron microscopy shows that the prepared CdS nanoparticles were dispersed and nearly uniform in diameter within the polymeric matrix.

Computational studies of the first order kinetic reactions for mononuclear copper(II) complexes having a hard-soft NS donor ligand.

The chelation behaviour of 4-((E)-2-(1-(thiophen-2-yl)ethylidene)hydrazinyl)-1-(4-methoxyphenyl)-1H-pyrrole-3-carbonitrile (HL) towards Cu(II) ions has been investigated. These Cu(II) complexes are characterized by elemental analyses, molar-solid conductance, ESR, FTIR and electronic spectral studies. Also, the kinetic and thermodynamic parameters (Ea, A, ΔH, ΔS, ΔG) for all thermal decomposition steps have been evaluated using Coats-Redfern and Horowitz-Metzger methods. Furthermore, antimicrobial activity of the ligand and its complexes were studied against Gram-negative bacteria: Escherichia coli, Gram-positive Bacillus cereus, Bacillus subtilis and pathogenic fungi Pseudomonas aeruginosa by using minimum inhibitory concentrations (MICs) method.

Characterization by combined optical and FT infrared spectra of 3d-transition metal ions doped-bismuth silicate glasses and effects of gamma irradiation.

Optical and infrared absorption spectral measurements were carried out for binary bismuth silicate glass and other derived prepared samples with the same composition and containing additional 0.2% of one of 3d transition metal oxides. The same combined spectroscopic properties were also measured after subjecting the prepared glasses to a gamma dose of 8 Mrad. The experimental optical spectra reveal strong UV-near visible absorption bands from the base and extended to all TMs-doped samples and these specific extended and strong UV-near visible absorption bands are related to the contributions of absorption from both trace iron (Fe(3+)) ions present as contaminated impurities within the raw materials and from absorption of main constituent trivalent bismuth (Bi(3+)) ions. The strong UV-near visible absorption bands are observed to suppress any further UV bands from TM ions. The studied glasses show obvious resistant to gamma irradiation and only small changes are observed upon gamma irradiation. This observed shielding behavior is related to the presence of high Bi(3+) ions with heavy mass causing the observed stability of the optical absorption. Infrared absorption spectra of the studied glasses reveal characteristic vibrational bands due to both modes from silicate network and the sharing of Bi-O linkages and the presence of TMs in the doping level (0.2%) causes no distinct changes within the number or position of the vibrational modes. The presence of high Bi2O3 content (70 mol%) appears to cause stability of the structural building units towards gamma irradiation as revealed by FTIR measurements.

Ultraviolet and infrared absorption spectra of Cr2O3 doped-sodium metaphosphate, lead metaphosphate and zinc metaphosphate glasses and effects of gamma irradiation: a comparative study.

The effects of gamma irradiation on spectral properties of Cr2O3-doped phosphate glasses of three varieties, namely sodium metaphosphate, lead metaphosphate and zinc metaphosphate have been investigated. Optical spectra of the undoped samples reveal strong UV absorption bands which are attributed to the presence of trace iron impurities in both the sodium and zinc phosphate glasses while the lead phosphate glass exhibits broad UV near visible bands due to combined absorption of both trace iron impurities and divalent lead ions. The effect of chromium oxide content has been investigated. The three different Cr2O3-doped phosphate glasses reveal spectral visible bands varying in their position and intensity and splitting due to the different field strengths of the Na(+), Pb(2+), Zn(2+) cations, together with the way they are housed in the network and their effects on the polarisability of neighboring oxygens ligands. The effects of gamma irradiation on the optical spectral properties of the various glasses have been compared. The different effects for lead and zinc phosphate are related to the ability of Pb(2+), and Zn(2+) to form additional structural units causing stability of the network towards gamma irradiation. Also, the introduction of the transition metal chromium ions reveals some shielding behavior towards irradiation. Infrared absorption spectra of the three different base phosphate glasses show characteristic vibrations due to various phosphate groups depending on the type of glass and Cr2O3 is observed to slightly affect the IR spectra. Gamma irradiation causes minor variations in some of the intensities of the IR spectra but the main characteristic bands due to phosphate groups remain in their number and position.

The button graft technique for perforations affecting less than 25% of the tympanic membrane: a non-randomised comparison of a new modification to cartilage tympanoplasty with underlay and overlay grafts.

OBJECTIVES: To evaluate a new composite cartilage-perichondrium graft (button graft) for repair of small-sized tympanic membrane perforations and to compare its success rate with that of the underlay and overlay techniques with temporal fascia or tragal perichondrium. DESIGN: Prospective, sequential allocation of surgical technique study. SETTING: Tertiary care university hospital. PATIENTS: One hundred 95 patients aged 14-42 years with central, uncomplicated tympanic membrane perforations with completely visualised margins affecting less than 25% of the tympanic membrane, distributed in three groups: 1 (underlay), 2 (overlay) and 3 (button graft). INTERVENTIONS: Patients were allocated in sequence to: 1 underlay graft, 2 overlay graft and 3 cartilage tympanoplasty with button graft technique. Patients were operated on under local anaesthesia. MAIN OUTCOME MEASURES: Postoperative status of the tympanic membrane, hearing improvement, duration of surgery and incidence of complications at 12 months postoperative. RESULTS: Group 1 (underlay) had 66 patients; group 2 (overlay), 65; and group 3 (cartilage), 66. Success was defined as the complete closure of the tympanic membrane one year after the operation. The success rates were 98.5% (65 of 66), 97% (63 of 65) and 98.5% (65 of 66) cases, and the mean air-bone gap gains were 10.18 (±5.4) dB, 8.5 (+6.5) dB and 9.1 (+5.1) dB for groups 1, 2 and 3, respectively. No bone conduction threshold or speech discrimination score worsening was noted. The mean durations of the operative procedure were 35 ± 8.4 (range 22,63), 42 ± 6.8 (range 33,75) and 23 ± 6.3 (range 15,41) min for groups 1, 2 and 3, respectively (P = 0.02). Tympanic membrane retraction occurred in three cases in underlay group 1, and tympanic membrane cholesteatoma pearls occurred in two cases in overlay group 2. CONCLUSIONS: The button graft technique is an effective and fast alternative for the repair of small tympanic membrane perforations if complete visualisation of the margin is possible. The shorter time taken with the button grafts is mainly due to the non-requirement for a skin incision. The results are comparable to those of the underlay and overlay techniques.

Defect formation of gamma irradiated MoO3-doped borophosphate glasses.

Borophosphate glasses of the basic composition (50P2O5, 30B2O3, 20Na2O mol%) containing different doping molybdenum oxide percents (0.16-0.98) were prepared by melting and annealing method. Infrared and UV-visible absorption spectroscopic measurements before and after gamma irradiation were carried out. The base undoped borophosphate glass reveals strong UV absorption bands but with no visible bands and these UV bands are related to unavoidable trace iron impurities contaminated within the raw materials used for the preparation of this glass. The introduction of MoO3 (in doping ratio) into this glass produces an additional UV band and a broad visible band and their intensities increase with the MoO3 content. These additional bands are related to both Mo(6+) and Mo(5+) ions. The base undoped borophosphate glass shows retardation effect towards gamma irradiation. Gamma irradiation produces marked changes in the UV-visible spectra of Mo-O3-doped glasses. Such changes can be related to the production of induced defects from photochemical reactions and the generation of positive holes. Infrared absorption spectrum of the undoped borophosphate glass reveals complex vibrational bands due to the presence of both phosphate groups beside borate groups with triangular and tetrahedrally coordinated units. The introduction of MoO3 causes some limited variations in the FTIR spectra. Gamma irradiation produces minor changes in the intensities of some IR bands. Such changes are related to the changes in the bond angles and/or bond lengths of few structural groups upon irradiation while the main structural groups remain unchanged in their number and position.