Silver-functionalized bismuth oxide (AgBi2O3) nanoparticles for the superior electrochemical detection of glucose, NO2- and H2O2.

In this study, silver-functionalized bismuth oxide (AgBi2O3) nanoparticles (SBO NPs) were successfully synthesized by a highly efficient hydrothermal method. The as-synthesized SBO nanoparticles were characterized using FT-IR, P-XRD, XPS, HR-SEM, and HR-TEM analytical methods. It was found that the NPs were in spherical shape and hexagonal crystal phase. The newly prepared SBO electrode was further utilized for the detection of glucose, NO2- and H2O2 by cyclic voltammetry (CV) and amperometric methods. The electrodes exhibited high sensitivity (2.153 µA mM-1 cm-2 for glucose, 22 µA mM-1 cm-2 for NO2- and 1.72 µA mM-1 cm-2 for H2O2), low LOD (0.87 µM for glucose, 2.8 µM for NO2- and 1.15 µM for H2O2) and quick response time (3 s for glucose, 2 s for both NO2- and H2O2 respectively). The sensor exhibited outstanding selectivity despite the presence of various interferences. The developed sensor exhibited good repeatability, reproducibility, and stability. In addition, the sensor was used to measure glucose, H2O2 in human serum, and NO2- in milk and river water samples, demonstrating its potential for use in the real sample.

Biosynthesis of Co3O4 nanomedicine by using Mollugo oppositifolia L. aqueous leaf extract and its antimicrobial, mosquito larvicidal activities.

Nanotechnology is a relatively revolutionary area that generates day-to-day advancement. It makes a significant impact on our daily life. For example, in parasitology, catalysis and cosmetics, nanoparticles possess distinctive possessions that make it possible for them in a broad range of areas. We utilized Mollugo oppositifolia L. aqueous leaf extract assisted chemical reduction method to synthesize Co3O4 nanoparticles. Biosynthesized Co3O4 Nps were confirmed via UV-Vis spectroscopy, scanning electron microscope, X-ray diffraction, EDX, Fourier-transform infrared, and HR-TEM analysis. The crystallite size from XRD studies revealed around 22.7 nm. The biosynthesized Co3O4 nanoparticle was further assessed for mosquito larvicidal activity against south-urban mosquito larvae Culex quinquefasciatus, and antimicrobial activities. The synthesized Co3O4 particle (2) displayed significant larvicidal activity towards mosquito larvae Culex quinquefasciatus with the LD50 value of 34.96 µg/mL than aqueous plant extract (1) and control Permethrin with the LD50 value of 82.41 and 72.44 µg/mL. When compared to the standard antibacterial treatment, Ciprofloxacin, the Co3O4 nanoparticle (2) produced demonstrates significantly enhanced antibacterial action against the pathogens E. coli and B. cereus. The MIC for Co3O4 nanoparticles 2 against C. albicans was under 1 µg/mL, which was much lower than the MIC for the control drug, clotrimale, which was 2 µg per milliliter. Co3O4 nanoparticles 2, with a MIC of 2 µg/mL, has much higher antifungal activity than clotrimale, whose MIC is 4 µg/mL, against M. audouinii.

Effect of Ca2+ ions on naphthalene adsorption/desorption onto calcium oxide nanoparticle: Adsorption isotherm, kinetics and regeneration studies.

The adsorptive nature of calcium oxide nanoparticles in aqueous sample of naphthalene in presence of Ca2+ ions was estimated. Enhanced efficiency of calcium oxide regeneration (90%) with the aid of calcium chloride in the solution concentration of 0.002-0.1 M was depicted. The less degree of toxic naphthalene desorption merged with SEM, FTIR and XRD characterization data portrays the importance of naphthalene adsorption onto calcium oxide using calcium chloride for regeneration. Batch adsorption studies were performed to evaluate the operating parameters such as pH, naphthalene concentration, contact time and impact of Ca2+ on naphthalene study. The adsorption isotherm of naphthalene on calcium oxide nanoparticle was described by Langmuir, Freundlich, Temkin and Dubinin Radushkevich and theoretical maximum monolayer adsorption capacity was found to be 63.81 mg/g at 303 K. The adsorption kinetic best fitted with pseudo second order kinetic model. The positive influence of making the addition of Ca2+ ions into naphthalene solution for its rapid adsorption was elucidated which is leaded by a probable increase in sorption capacity for naphthalene molecules at lower concentrations. The stable nature of crystallinity of calcium oxide and a less degree of naphthalene molecules leaching during consecutive cycles of adsorptive process and nanoparticle regeneration was also scrutinized.

Cerium-polysulfide redox flow battery with possible high energy density enabled by MFI-Zeolite membrane working with acid-base electrolytes.

A pH change can enable high-energy-density RFB (redox flow battery) in an aqueous medium. Nevertheless, a membrane to prevent the ion crossover is needed. This study adopted cerium and polysulfide in an acid-base combined electrolyte with an MFI-Zeolite membrane as a separator. The increased potential with pH change is described by the OCP (open circuit potential) difference, which varies by 0.8 V for the combination of acid-acid and acid-base electrolyte. A decrease of 350 mV at the redox peak potential of Ce3+/Ce4+ and a 10 mV negative potential shift for S42-/2S22- highlights the pH effect between the combination of acid-acid and acid-base electrolyte indicates the influence of pH leading in half-cell of anodic than the opposite cathodic side. The UV-visible spectral analysis for Ce3+ and S42- ions displacement shows that cerium and sulfur ions do not migrate to each other half-cell through an MFI-Zeolite membrane. As a result, the current efficiency of 94%, voltage, and energy efficiency of 40%-43% were attained at a current density of 10 mA cm-2. Moreover, the acid-base composition of the Ce/S system showed an energy density of 378.3 Wh l -1.

Highly efficient and simultaneous catalytic reduction of multiple toxic dyes and nitrophenols waste water using highly active bimetallic PdO-NiO nanocomposite.

Azo dyes and nitrophenols have been widely used in the various industry which are highly toxic and affecting the photosynthetic cycle of aquatic organism. The industry disposals increase the accumulation of azo compounds in the environment. In the present study, we synthesized the low cost, PdO-doped NiO hetero-mixture via simple hydrothermal combined calcination process. The morphology results proved that, the spherical PdO nanoparticles are evenly doped with NiO nanoparticles. The band gap values of metal oxides NiO, PdO and PdO-NiO composite were found to be 4.05 eV, 3.84 eV and 4.24 eV, respectively. The high optical bandgap (Eg) value for composite suggests that the PdO interface and NiO interface are closely combined in the composite. The catalytic activity of the PdO-NiO was analyzed for the reduction of different toxic azo compounds namely, 4-nitrophenol (NP), 2,4-dinitrophenol (DNP), 2,4,6-trinitrophenol (TNP), methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) separately and their mixture with the presence of a NaBH4. For the first time, the large volume of the toxic azo compounds was reduced into non-toxic compounds with high reduction rate. The proposed PdO-NiO catalyst exhibit excellent rate constant 0.1667, 0.0997, 0.0686 min-1 for NP, DNP and TNT and 0.099, 0.0416 and 0.0896 min-1 for MB, RhB and MO dyes respectively which is higher rate constant than the previously reported catalysts. Mainly, PdO-NiO completes the reduction of mixture of azo compounds within 8 min. Further, PdO-NiO exhibit stable reduction rate of azo compounds over five cycles with no significant loss. Hence, the proposed low cost and high efficient PdO-NiO catalyst could be the promising catalyst for degradation of azo compounds.

Enhanced sustainable electro-generation of a Ni (I) homogeneous electro-catalyst at a silver solid amalgam electrode for the continuous degradation of N2O, NO, DCM, and CB pollutants.

This paper reports the sustainable and enhanced generation of a Ni(I) active electro-catalyst using AgSAE as a cathode material for the sustainable degradation of N2O, NO, dichloromethane (DCM), and chlorobenzene (CB) by electroscrubbing in a series operation. The AgSAE electrode showed 1.66 times higher Ni(I) formation than the Ag metal electrode. The AgSAE achieved 20% ± 2% Ni(I) generation in a highly concentrated alkaline medium, whereas Ag metal only achieved 12% ± 2% Ni(I) generation at the same current density. Electrochemical impedance spectroscopy and voltammetric studies determined that the kinetics of the charge-transfer reaction was also preferential at the AgSAE, with the cathodic peak at -1.26 V vs. Ag/AgCl confirming Ni(I) formation. Initially, the change in the oxygen reduction potential and reduction efficiency of Ni(I) confirmed the removal of N2O, NO, DCM and CB. In addition, the gas Fourier transform infrared (FTIR) spectrum revealed 99.8% removal efficiency of toxic pollutants. Therefore, the regeneration of Ni(I) confirmed the sustainable removal of toxic pollutants. Furthermore, the FTIR spectra revealed the formation of NH3 during the reduction of N2O and NO. On the other hand, DCM and CB were reduced to benzene derivatives in the solution phase. In addition, a plausible reduction mechanism was derived. As a result, the AgSAE cathode exhibited two-fold higher removal efficiency of N2O, NO, DCM, and CB than the previously reported electrodes.

Tetracyanonickelate (II)/KOH/reduced graphene oxide fabricated carbon felt for mediated electron transfer type electrochemical sensor for efficient detection of N2O gas at room temperature.

N2O is the most significant anthropogenic greenhouse gas, which cause the ozone depletion. Hence, the room temperature detection of N2O is highly desirable. In this work, The TCN(II)-KOH-rGO/CF modified electrode was successfully fabricated by drop coating method. The synthesized electrode was successfully characterized by SEM, TEM, FT-IR and XRD. The sensor electrode was used to detect different N2O concentration in flow conditions at room temperature. TCN(II)-KOH-rGO/CF modified electrode showed high sensitivity towards N2O, a wide range from 1ppm to 16 ppm and low detection of 1 ppm N2O were achieved for the TCN(II)-KOH-rGO/CF modified electrode. The limit of detection and the response towards this nitrogen oxide is competitive to other sensing methods. In addition, the sensitivity of the electrochemical sensor electrode was compared with the online Gas Chromatography. Additionally, the selectivity of the working electrode was analyzed and specified. The working electrode stability was analyzed for more than 30 days shows good stability. The fabricated TCN(II)-KOH-rGO/CF electrode is easier to prepare to get excellent analytical performance towards N2O. Hence, the proposed TCN(II)-KOH-rGO/CF electrode could be the suitable material for detection of N2O in the real site process.

Synthesis of porous 2D layered nickel oxide-reduced graphene oxide (NiO-rGO) hybrid composite for the efficient electrochemical detection of epinephrine in biological fluid.

In the present research work, 2D-Porous NiO decorated graphene nanocomposite was synthesized by hydrothermal method to monitored the concentration of epinephrine (EPI). The morphology (SEM and TEM) results confirmed 2D-Porous NiO nanoparticles firmly attached over graphene nanosheets. FTIR and XPS analysis confirmed the formation of nickel oxide formation and complete reduction of GO to rGO. The electrochemical activity of the proposed NiO-rGO/GCE modified electrode on epinephrine was analyzed by simple cyclic voltammetry technique. The proposed low cost NiO-rGO/GCE modified electrode showed excellent catalytic activity over GCE and rGO/GCE electrodes. Due to its high conductivity and charge transfer ability of the NiO-rGO/GCE modified electrode exhibited high sensitivity of EPI at optimized conditions. The anodic peak current of the EPI linearly increases with increasing the concertation of EPI. A wide linear range (50 µM-1000 µM) was achieved with high correlation coefficient (R2 = 0.9986) and the limit of detection (LOD) of NiO-rGO/GCE modified electrode was calculated to be 10 µM. NiO-rGO/GCE electrode showed good stability and repeatability towards the EPI oxidation. Mainly, the proposed NiO-rGO/GCE modified electrode showed good sensitivity of EPI in the human biological fluid with high recovery percentage. The low cost, NiO-rGO/GCE electrode could be the promising sensor electrode for the detection of Epinephrine in the real samples.

Neodymium (Nd) based oxide perovskite nanostructures for photocatalytic and photoelectrochemical water splitting functions.

Neodymium (Nd) based perovskite (Nd1-xCoxFeO3) nanostructures were processed to address the rising energy and environment crisis through offering solutions by photocatalytic and photoelectrochemical (PEC) water splitting reactions. The impact of cobalt (Co) ions on the physicochemical properties of Nd-perovskites were studied using X-ray diffraction (XRD), Raman and electron microscopic instruments. The interaction of metal ions was studied in depth via X-ray photoelectron spectroscopy (XPS). Absorption and photoluminescence signals inferred the optical band gap to be lowered and defect states to increase upon Co substitution. Improved photocatalytic efficacy in Nd1-xCoxFeO3 was evaluated by comparative studies using NdFeO3. Secondly, the enhanced conductivities in Nd1-xCoxFeO3 studied via Nyquist plot was found to be advantageous in photoelectrode fabrication for PEC functions. Time-dependent photocurrent density results affirmed the stability in processed devices. Co ions were also inferred to boost the separation of charge carriers effectively. The improved performance in Nd1-xCoxFeO3 nanostructures were well justified to the successful incorporation of Co ions that sway the Nd-O, Co-O and Co-Fe-O bondings and boost the photon absorption and electronic conductivity to facilitate the observed performance.

A facile and green synthesis of CuO/NiO nanoparticles and their removal activity of toxic nitro compounds in aqueous medium.

In this present work, we report the green synthesis of mixed bimetal oxides (CuO/NiO) for the efficient reduction of toxic nitrophenols (NP, DNP and TNP) in aqueous medium. The CuO/NiO NPs were synthesized by green hydrothermal method combined calcination process. The physiochemical properties of the synthesized CuO/NiO NPs were systematically characterized by using XRD, XPS, FTIR, SEM, and HR-TEM techniques. The calcinated CuO/NiO NPs XRD pattern and SEM morphology show the high crystalline nature than the non-calcinated. Whereas, the XPS and FTIR results confirmed the formation of the metal oxide bonding and the interaction of the bimetals. The HR-TEM images showed the spherical crystals with average particle size about 25 nm. In addition, the SAED pattern confirmed the polycrystalline nature of CuO/NiO NPs. The catalytic reduction of nitro compounds to amino derivative was studied with reducing agent (NaBH4). The CuO/NiO NPs showed the high catalytic activity and completed the reduction reaction of NP, DNP and TNP with in 2, 5 and 10 min respectively. In addition, CuO/NiO NPS exhibited the excellent kinetic rate constant k value about 1.519, 0.5102, 0.4601 min-1 for NP, DNP and TNP respectively. Furthermore, the conversion product aminophenol was observed for these three nitro compounds. The proposed CuO/NiO NPs showed excellent crystal stability after the nitrophenol reduction reactions. An inexpensive CuO/NiO NPs is a promising catalysts for reduction of toxic nitro compounds to useful products in aqueous or non-aqueous medium.

Synthesis of hierarchically structured T-ZnO-rGO-PEI composite and their catalytic removal of colour and colourless phenolic compounds.

Phenolic compounds bisphenol A (BPA) and 4-nitrophenol (4-NP) are the prime water contaminants. As reported, these compounds are some of the highly hazardous ones to the human and living species. In this study, T-ZnO-rGO-PEI composite was synthesized employing hydrothermal method and the obtained composite samples were systematically characterized by FTIR, XPS, FE-SEM and HR-TEM studies. The FTIR, XPS analysis confirmed the successful surface modification of T-ZnO-rGO-PEI composite. The FE-SEM morphology confirmed the formation of ZnO (arm length about 2.5 µm) tetrapod structured in synthesized T-ZnO-rGO-PEI composite. The thickness of formed ZnO arm (0.44 µm) was increased after the polymer coating which confirmed the successful surface modification by PEI polymer. The HR-TEM images confirm the uniform coating of PEI polymer on T-ZnO-rGO surface. The catalytic activity and adsorption capacity of the synthesized T-ZnO-rGO-PEI composite was successfully explored using 4-nitrophenol and bisphenol-A as model pollutants .T-ZnO-rGO-PEI composite and found that 4-NP reduction reaction was completed within 10 min with the rate of 0.224 min-1. The BPA adsorption over T-ZnO-rGO-PEI exhibited high adsorption rate of 0.0210 min-1. In addition, the detailed 4-NP reduction and BPA adsorption mechanism was demonstrated. Hence the synthesized T-ZnO-rGO-PEI composite is a promising catalyst for the removal of micropollutants in aqueous medium.

A facile synthesis of metal ferrites and their catalytic removal of toxic nitro-organic pollutants.

Nitrocompounds are the major prime water contaminants. In this investigative study, toxic nitrocompounds (4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol) were removed by using magnetic CuFe2O4, CoFe2O4, and NiFe2O4 material systems. The metal ferrites were synthesized through hydrothermal method and also followed with calcination process. The properties of metal ferrites were confirmed through using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FE-SEM) studies and results there on were presented. For the first time, the synthesized CuFe2O4, CoFe2O4, and NiFe2O4 material systems were used for the reduction of 4-nitrophenol (NP), 2,4-dinitrophenol (DNP), and 2,4,6-trinitrophenol (TNP) in aqueous medium. The UV-visible spectrometry was employed to monitor the removal of nitro compounds and formation of aminophenol. Among, the three catalysts, the CuFe2O4 displayed excellent removal activity for nitrocompounds. The CuFe2O4 nanoparticles completely removed the NP, DNP and TNP within 2, 5, 10 min, respectively. The NP reduction reaction follows the pseudo-first-order kinetics. Further, the investigated and proposed CuFe2O4, catalyst has given and demonstrated excellent kinetic rate constants 0.990, 0.317, 0.184 min-1 for 4-NP, DNP and TNP respectively, which was very fast kinetic than the already published reports. Also, the aminophenol formation was confirmed for the above mentioned and select nitrocompounds. The obtained results confirm suggest that CuFe2O4 nanoparticles based material system could be one of the promising catalysts for nitro compounds removal process.

Surface-tuned hierarchical ɤ-Fe2O3-N-rGO nanohydrogel for efficient catalytic removal and electrochemical sensing of toxic nitro compounds.

4- Nitrophenol (4-NP) is a top rated hazardous environmental pollutant and secondary explosive chemicals. For the sake of ecology and environment safety, the catalytic reduction and detection of 4-NP is highly important. In this work, ɤ-Fe2O3-nitrogen doped rGO (ɤ-Fe2O3-N-rGO) nanohydrogel was synthesized by green hydrothermal method. The morphology and phase purity of prepared ɤ-Fe2O3-N-rGO nanohydrogel were confirmed by various analytical (SEM, TEM, XRD, and XPS) and electrochemical techniques. The morphological structure of ɤ-Fe2O3-N-rGO nanohydrogel confirmed that the nanocrystals are well covered over the 2D N-rGO layer. Further, ɤ-Fe2O3-N-rGO nanohydrogel was applied for the catalytic reduction and electrochemical detection of ecotoxic 4-NP. A low cost, ɤ-Fe2O3-N-rGO nanohydrogel displayed an excellent catalytic activity, high recyclability (>5 cycles) and high conversion efficiency of 4-NP to 4-Aminophenol (4-AP). In addition, ɤ-Fe2O3-N-rGO nanohydrogel modified GCE displayed a wide linear sensing range (0.1-1000 µM), and a low detection limit (LOD) of 0.1 µM with excellent sensitivity, high selectivity (<1.2%) and good stability (>4 weeks). The developed sensor electrode shows the low reduction potential of -0.3 V and -0.60 V for the determination of 4-NP. The proposed ɤ-Fe2O3-N-rGO nanohydrogel is promising catalyst for the detection and removal of toxic aromatic nitro compounds in real site applications.

Sustainable removal of N2O by mediated electrocatalytic reduction at ambient temperature electro-scrubbing using electrogenerated Ni(I) electron mediator.

Direct catalysis is generally proposed for nitrous oxide (N2O) abatement but catalysis is expensive, requires high temperatures, and suffers from media fouling, which limits its lifetime. In the present study, an ambient temperature electroscrubbing method was developed, coupling wet-scrubbing with an electrogenerated Ni(I) ([Ni(I)(CN)4]3-) mediator, to enable N2O reduction in a single process stage. The initial studies of 10 ppm N2O absorption into 9 M KOH and an electrolyzed 9 M KOH solution showed no removal. However, 95% N2O removal was identified through the addition of Ni(I) to an electrolyzed 9 M KOH. A change in the oxidation/reduction potential from -850 mV to -650 mV occurred following a decrease in Ni(I) concentration from 4.6 mM to 4.0 mM, which confirmed that N2O removal was mediated by an electrocatalytic reduction (MER) pathway. Online analysis identified the reaction product to be ammonia (NH3). Increasing the feed N2O concentration increased NH3 formation, which suggests that a decrease in electrolyzed solution reactivity induced by the increased N2O load constrained the side reaction with the carrier gas. Importantly, this study outlines a new regenerable method for N2O removal to commodity product NH3 at ambient temperature that fosters process intensification, overcomes the limitations generally observed with catalysis, and permits product transformation to NH3.

Electrochemically generated bimetallic reductive mediator Cu1+[Ni2+(CN)4]1- for the degradation of CF4 to ethanol by electro-scrubbing.

Remediation of electronic gas CF4 using commercially available technologies results in another kind of greenhouse gas and corrosive side products. This investigation aimed to develop CF4 removal at room temperature with formation of useful product by attempting an electrogenerated Cu1+[Ni2+(CN)4]1- mediator. The initial electrolysis of the bimetallic complex at the anodized Ti cathode demonstrated Cu1+[Ni2+(CN)4]1- formation, which was confirmed by additional electron spin resonance results. The degradation of CF4 followed mediated electrochemical reduction by electrogenerated Cu1+[Ni2+(CN)4]1-. The removal efficiency of CF4 of 95% was achieved by this electroscrubbing process at room temperature. The spectral results of online and offline Fourier transform infrared analyzer, either in gas or in solution phase, demonstrated that the product formed during the removal of CF4 by electrogenerated Cu1+[Ni2+(CN)4]1- by electroscrubbing was ethanol (CH3CH2OH), with a small amount of trifluoroethane (CF3CH3) intermediate.

A genomic case study of mixed fibrolamellar hepatocellular carcinoma.

BACKGROUND: Mixed fibrolamellar hepatocellular carcinoma (mFL-HCC) is a rare liver tumor defined by the presence of both pure FL-HCC and conventional HCC components, represents up to 25% of cases of FL-HCC, and has been associated with worse prognosis. Recent genomic characterization of pure FL-HCC identified a highly recurrent transcript fusion (DNAJB1:PRKACA) not found in conventional HCC. PATIENTS AND METHODS: We performed exome and transcriptome sequencing of a case of mFL-HCC. A novel BAC-capture approach was developed to identify a 400 kb deletion as the underlying genomic mechanism for a DNAJB1:PRKACA fusion in this case. A sensitive Nanostring Elements assay was used to screen for this transcript fusion in a second case of mFL-HCC, 112 additional HCC samples and 44 adjacent non-tumor liver samples. RESULTS: We report the first comprehensive genomic analysis of a case of mFL-HCC. No common HCC-associated mutations were identified. The very low mutation rate of this case, large number of mostly single-copy, long-range copy number variants, and high expression of ERBB2 were more consistent with previous reports of pure FL-HCC than conventional HCC. In particular, the DNAJB1:PRKACA fusion transcript specifically associated with pure FL-HCC was detected at very high expression levels. Subsequent analysis revealed the presence of this fusion in all primary and metastatic samples, including those with mixed or conventional HCC pathology. A second case of mFL-HCC confirmed our finding that the fusion was detectable in conventional components. An expanded screen identified a third case of fusion-positive HCC, which upon review, also had both conventional and fibrolamellar features. This screen confirmed the absence of the fusion in all conventional HCC and adjacent non-tumor liver samples. CONCLUSION: These results indicate that mFL-HCC is similar to pure FL-HCC at the genomic level and the DNAJB1:PRKACA fusion can be used as a diagnostic tool for both pure and mFL-HCC.

Gaseous trichloroethylene removal using an electrochemically generated homogeneous low-valent ligand-free Co(I) electrocatalyst by electro-scrubbing.

The interest in heterogeneous Co(OH)2 electrocatalysts for energy applications has increased steadily. This study focused on a ligand-free homogeneous electrocatalyst for the degradation of gaseous trichloroethylene (TCE) in NaOH in a divided electrolytic cell. The initial electrolysis results revealed a change in the oxidation reduction potential (ORP) of [Co(II)(OH)4](2-) (Co(II)) from -267 mV to -800 mV on anodized Ti during electrolytic reduction identifies low-valent homogeneous [Co(I)(OH)4](3-)(Co(I)) formation in 10 M NaOH. Cyclic voltammetry analysis of Co(II) at different anodized electrodes, Ag, carbon and Ti, in a 10 M NaOH solution, showed no stripping like peak in the reverse scan only the Ti electrode, supporting the formation of low-valent Co(I). UV-vis spectral analysis of the electrolyzed solution showed an enhanced peak corresponding to metal-to-ligand transition, demonstrates Co(I) formation. Co(II) reduction reached a maximum yield of 18% at 30 mA cm(-2) on an anodized Ti cathode. For gaseous TCE removal, continuous mode electro-scrubbing was adopted and degradation was monitored using an online FTIR gas analyzer that showed 99.75% degradation of TCE in the presence of homogeneous Co(I). Three consecutive regenerations of Co(I) and degradation steps of TCE confirmed the possibility of industrial applications in a sustainable manner.

Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: antimicrobial evaluation and anticancer studies.

Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by (1)H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M=Cu(II), Co(II)), Zn(II), or VO(IV); MPMP=2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X=Cl, (L1H), X=Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: synthesis, spectral characterization, antimicrobial and nuclease studies.

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA=Schiff base and B=2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, (1)H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, (1)H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

How much of virus-specific CD8 T cell reactivity is detected with a peptide pool when compared to individual peptides?

Immune monitoring of T cell responses increasingly relies on the use of peptide pools. Peptides, when restricted by the same HLA allele, and presented from within the same peptide pool, can compete for HLA binding sites. What impact such competition has on functional T cell stimulation, however, is not clear. Using a model peptide pool that is comprised of 32 well-defined viral epitopes from Cytomegalovirus, Epstein-Barr virus, and Influenza viruses (CEF peptide pool), we assessed peptide competition in PBMC from 42 human subjects. The magnitude of the peptide pool-elicited CD8 T cell responses was a mean 79% and a median 77% of the sum of the CD8 T cell responses elicited by the individual peptides. Therefore, while the effect of peptide competition was evident, it was of a relatively minor magnitude. By studying the dose-response curves for individual CEF peptides, we show that several of these peptides are present in the CEF-pool at concentrations that are orders of magnitude in excess of what is needed for the activation threshold of the CD8 T cells. The presence of such T cells with very high functional avidity for the viral antigens can explain why the effect of peptide competition is relatively minor within the CEF-pool.