Amperometric determination of hydrazine using a CuS-ordered mesoporous carbon electrode.

An electrocatalytic sensor for hydrazine using copper sulfide-ordered mesoporous carbon (CuS-OMC) is described. A facile solvothermal synthetic strategy was adopted for CuS-OMC and the ordered mesoporous carbon was obtained through nanocasting method. The synthesized CuS-OMC was characterized using microscopic and spectrochemical techniques. CuS-OMC was immobilized on GCE and evaluated for its electrochemical sensing of hydrazine using cyclic voltammetry and amperometry. CuS-OMC modified GCE exhibited better hydrazine sensing at an optimized pH 7.4 in terms of oxidation potential and current compared with that of GCE, CuS, and OMC. The observed sensing performance of CuS-OMC was attributed to the presence of Cu (I/II) in CuS dispersed in OMC which acts as an electrocatalytic center for the sensing of hydrazine. Amperometry under optimized experimental condition with an applied potential of 270 mV was employed to obtain a linear calibration plot in the range 0.25 to 40 µM (R2 = 0.9908) with a detection limit of 0.10 µM with a sensitivity of 0.915 (± 0.02) µA cm-2 µM-1. Real sample analyses were carried out by spiking of hydrazine in different water samples and the recoveries were in the range of 97 ± 2.1% (n = 3). Graphical abstract.

Investigation on removal of malachite green using EM based compost as adsorbent.

The discarded materials from different sources can be utilized as effective materials in wastewater remediation. This proposed study was aimed mainly to investigate the possibility of Effective Microorganisms based compost (EMKC), which is derived from the kitchen solid waste, as a non-conventional low cost adsorbent for the removal of malachite green from aqueous solution. Batch experiments were carried out to evaluate the optimum operating parameters like pH (2-9), initial dye concentration (50-1000mg/L), adsorbent particle size (0.6-2.36mm) and adsorbent dosage (2-12g/L). EMKC recorded maximum uptake of 136.6mg/g of MG at pH 8, initial dye concentration 1000mg/L, adsorbent particle size 1.18mm and adsorbent dosage 4g/L. Two and three parameter adsorption models were employed to describe experimental biosorption isotherm data. The results revealed that the Sips model resulted in better fit than other models. The pseudo-first and -second order models were applied to describe kinetic data, of which the pseudo-second order described experimental data better with high correlation coefficient. This investigation suggested that EMKC could be an effective and low cost material for the removal of malachite green dye from aqueous solution.

Synthesis of new cis-fused tetrahydrochromeno[4,3-b]quinolines and their antiproliferative activity studies against MDA-MB-231 and MCF-7 breast cancer cell lines.

New cis-fused tetrahydrochromeno[4,3-b]quinolines have been synthesized by intramolecular [4+2] imino-Diels-Alder reactions of 2-azadienes derived in situ from aromatic amines and 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones in the presence of 20mol% Yb(OTf)(3) in acetonitrile under reflux conditions in good to excellent yields. The structures were established by spectroscopic data and further confirmed by X-ray diffraction analysis. These compounds were evaluated for their antiproliferative activity against MDA-MB-231 and MCF-7 breast cancer cells. The results showed that compounds 3e, 3f, and 3k exhibit significant antiproliferative activity against MCF-7 breast cancer cells and low inhibitory activity against MDA-MB-231 breast cancer cell lines. Compound 3h displayed activity as comparable to tamoxifen on both the cell lines.

Exploring the synergistic effect of NixSn2xS4x thiospinel with MWCNTs for enhanced performance in dye-sensitized solar cells, the hydrogen evolution reaction, and supercapacitors.

Trifunctional nickel tin sulfide (NixSn2xS4x) with a thiospinel-like structure composited with multiwalled carbon nanotubes (MWCNTs) (M-NixSn2xS4x) was synthesized by a facile method. The unit cell arrangement of the prepared composite was studied by density functional theory, and the theoretical interpretation satisfactorily inferred the presence of a synergistic effect between the thiospinel and MWCNTs. The high metallic conductivity and superior electrocatalytic activity of the M-NixSn2xS4x composite endow it with diverse applications. The composite shows promise as a counter electrode for dye-sensitized solar cells (efficiency of 4.67% for fluorine-doped indium tin oxide compared to 5.23% for platinum); an efficient catalyst for the hydrogen evolution reaction with good cycling stability and a low overpotential of -41 mV at a cathode current density of 10 mA cm2 and a Tafel slope of 43 mV dec-1 on a graphite sheet electrode; and an impressive capacitance material on a graphite sheet electrode alternative to expensive current collectors such as Ni foam, with a specific capacitance value of 1200 F g-1 at a current density of 1 A g-1 and a long life span of 92.6% that is retained for up to 15 000 cycles.

Effect of 1-aminobenzotriazole on the in vitro metabolism and single-dose pharmacokinetics of chlorzoxazone, a selective CYP2E1 substrate in Wistar rats.

The aim of this study was to study the effect of 1-aminobenzotriazole (ABT) on in vitro metabolism, oral, and intravenous (IV) pharmacokinetics of chlorzoxazone (CZX) in rats. Enzyme kinetics of CZX was performed with rat and human liver microsomes and pure isozyme (CYP2E1) with and without ABT. The enzyme kinetics (V(max) and K(m)) of the formation of 6-hydroxychlorzoxazone (OH-CZX) was found to be similar among rat liver microsomes (3486 pmol mg protein(-1) min(-1) and 345 microM), human liver microsomes (3194 pmol mg protein(-1) min(-1) and 335 microM) and pure isozyme (3423 pmol mg protein(-1) min(-1) and 403 microM), but K(I) and K(inact) values for ABT towards the ability to inhibit the formation of OH-CZX from CZX varied between liver microsomes (rat: 32.09 microM and 0.12 min(-1); human: 27.19 microM and 0.14 min(-1)) and pure isozyme (3.18 microM and 0.29 min(-1)). The novel robust analytical method was capable of quantifying CZX, OH-CZX, and ABT simultaneously in a single run, and the method was used for both in vitro and in vivo studies. Pre-treatment of rats with ABT prior to oral and IV administration of CZX significantly decreased the clearance (threefold) and consequently increased the AUC of CZX (approx. three- to fourfold). When rats were pre-treated with ABT, the formation of OH-CZX was completely blocked after oral and IV administration; however, we were able to measure OH-CZX in rats administered with CZX by oral and IV routes without pre-treatment of ABT. The oral bioavailability of CZX was approximately 71% when dosed alone and reached 100% under pre-treatment with ABT. The t(1/2) values of CZX was significantly prolonged for oral dosing compared with IV dosing under pre-treated conditions with ABT, suggesting an involvement of pre-systemic component in the disposition of CZX. The pharmacokinetic parameters of ABT did not change when it was dosed along with CZX (oral and IV), indicating that either CZX or OH-CZX had no effect on disposition of ABT. The plasma concentrations of ABT were above and beyond the required levels to inhibit CYP2E1 enzyme for at least 36 h post-treatment.

Outcome of patients with systemic lupus erythematosus in intensive care unit.

The objective of the study was to identify the causes, outcome and prognosis of severe illness in patients with systemic lupus erythematosus (SLE) requiring intensive care unit (ICU) care in a University Hospital over a five-year period. The design was a cohort study. Forty-eight SLE patients requiring ICU management over a five-year period (January 1997-December 2001) were studied prospectively. Of 48 patients, 14 (29.2%) died, predominantly with multiorgan dysfunction syndrome (MODS). Patients whose APACHE II score was equal to or greater than 20 had higher mortality than those with APACHE score below 20 (60 versus 7.1%; and P < 0.01). All the 18 patients whose health status rated as 'good' survived, while 46.7% of 30 patients whose health rated as 'poor' died (P < 0.01). Patients who had thrombocytopenia associated with sepsis and/or disseminated intravascular coagulopathy (DIC) had the highest mortality (75%, five-year survival). In conclusion, SLE patients admitted to the ICU had a lower mortality rate than some of the previous reports. Patients with SLE with high APACHE score, > or =20, poor health status, thrombocytopenia and multiorgan dysfunction syndrome had poor prognosis in the ICU.