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ZrCoSb based half-Heusler (HH) alloys have been widely studied as a p-type thermoelectric (TE) material for power generation applications in the mid-temperature regime. However, their intrinsically high thermal conductivity has been found to be detrimental for the improvement in their thermoelectric figure-of-merit (ZT), which presently is far below unity. In the current work, a state-of-the-art ZT ∼1.1 at 873 K was realized in an optimized composition of nanostructured Zr1-xHfxCoSb0.9Sn0.1 HH alloys by employing compositional modulation i.e. grain-by-grain compositional variations, which leads to a substantial increase in its power factor coupled with a concurrent decrease in its thermal conductivity. Significant reduction in the phonon mean-free-path is observed on Hf substitution, which is comparable to the average crystallite size (∼25 nm), thus leading to a very low thermal conductivity of ∼2.2 W m−1K−1 at 873 K, which is amongst the lowest reported in HH alloys. The TE device characteristics, estimated using cumulative temperature dependence model for quantitative evaluation of TE performance, yielded an output power density of ∼10 Wcm−2 with a leg efficiency of ∼10% in the optimized composition of nanostructured Zr1-xHfxCoSb0.9Sn0.1 HH alloys, which is comparable to the reported efficiencies of other state-of-the-art TE materials. Keywords: Half Heuslers, Iso-electronic, Waste heat recovery, Mid-temperature, Efficiency, Compositional modulation

Introduction: Despite considerable benefits associated with current drug-eluting stents, continued attention to the safety, efficacy, and deliverability of available drug-eluting stent has led to the development of newer stent. Methods: This study was a single-centre, prospective, non-randomized, first-in-man study which included clinical follow-up data was collected at 1, 8 and 12 months after the procedure. The study included 105 patients with de novo native coronary artery lesions including multi-vessel disease treated with Supralimus-Core® stent. Repeat angiography was performed 8 months post-stent implantation. Results: At quantitative coronary angiography 8-month luminal late loss was 0.39 ± 0.33 mm in-stent and 0.33 ± 0.35 mm in-segment. The incidence of any major adverse cardiac event at 30 days, 8 months and 12 months was 1 (1%), 6 (6%) and 7 (7%) respectively. Conclusion: This study demonstrates that the Supralimus-Core® SES is a safe and effective treatment for patients with obstructive coronary artery disease. ClinicalTrials.gov ID: NCT00811616.

Although lockdown of the industrial and transport sector and stay at home advisories to counter the COVID-19 pandemic have shown that the air quality has improved during this time, very little is known about the role of ambient air pollutants and meteorology in facilitating its transmission. This paper presents the findings from a study that was conducted to evaluate whether air quality index (AQI), three primary pollutants (PM 2.5 , PM 10 and CO), Ground level ozone (O 3 ) and three meteorological variables (temperature, relative humidity, wind speed) have promoted the COVID-19 transmission in five megacities of India. The results show significant correlation of PM 2.5 , PM 10 , CO, O 3 concentrations, AQI and meteorological parameters with the confirmed cases and deaths during the lockdown period. Among the meteorological variables considered, temperature strongly correlated with the COVID-19 cases and deaths during the lockdown (r=0.54;0.25) and unlock period (r=0.66;0.25). Among the pollutants, ozone, and among the meteorological variables, temperature, explained the highest variability, up to 34% and 30% respectively, for COVID-19 confirmed cases and deaths. AQI was not a significant parameter for explaining the variations in confirmed and death cases. WS and RH could explain 10-11% and 4-6% variations of COVID-19 cases. A GLM model could explain 74% and 35% variability for confirmed cases and deaths during the lockdown and 66% and 19% variability during the unlock period. The results suggest that meteorological parameters may have promoted the COVID-19 incidences, especially the confirmed cases. Our findings may encourage future studies to explore more about the role of ambient air pollutants and meteorology on transmission of COVID-19 and similar infectious diseases., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Cars are a commuting lifeline worldwide, despite contributing significantly to air pollution. This is the first global assessment on air pollution exposure in cars across ten cities: Dhaka (Bangladesh); Chennai (India); Guangzhou (China); Medellín (Colombia); São Paulo (Brazil); Cairo (Egypt); Sulaymaniyah (Iraq); Addis Ababa (Ethiopia); Blantyre (Malawi); and Dar-es-Salaam (Tanzania). Portable laser particle counters were used to develop a proxy of car-user exposure profiles and analyse the factors affecting particulate matter ≤2.5 μm (PM 2.5 ; fine fraction) and ≤10 μm (PM 2.5 - 10 ; coarse fraction). Measurements were carried out during morning, off- and evening-peak hours under windows-open and windows-closed (fan-on and recirculation) conditions on predefined routes. For all cities, PM 2.5 and PM 10 concentrations were highest during windows-open, followed by fan-on and recirculation. Compared with recirculation, PM 2.5 and PM 10 were higher by up to 589% (Blantyre) and 1020% (São Paulo), during windows-open and higher by up to 385% (São Paulo) and 390% (São Paulo) during fan-on, respectively. Coarse particles dominated the PM fraction during windows-open while fine particles dominated during fan-on and recirculation, indicating filter effectiveness in removing coarse particles and a need for filters that limit the ingress of fine particles. Spatial variation analysis during windows-open showed that pollution hotspots make up to a third of the total route-length. PM 2.5 exposure for windows-open during off-peak hours was 91% and 40% less than morning and evening peak hours, respectively. Across cities, determinants of relatively high personal exposure doses included lower car speeds, temporally longer journeys, and higher in-car concentrations. It was also concluded that car-users in the least affluent cities experienced disproportionately higher in-car PM 2.5 exposures. Cities were classified into three groups according to low, intermediate and high levels of PM exposure to car commuters, allowing to draw similarities and highlight best practices., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Indoor Air Pollution (IAP) is one of the top environmental risks in developing countries including India, with more than a million deaths annually, predominantly through Particulate Matter (PM) exposure. The current study deals with the measurement of PM concentrations in rural households under varied fuel and kitchen-types, evaluation of the indoor air pollution (IAP) characteristics and estimation of respiratory dosage for the different subjects (women, young children and the elderly). Monitoring of particulate matter (PM) was carried out during summer, monsoon and winter season with biomass, LPG and combine of biomass and LPG being used as fuel for cooking. Furthermore, different types of indoor kitchens (with partition and without partition) and outdoor kitchens (separate enclose kitchen and open kitchen) were also considered as kitchen type along with fuel are two crucial factors contributing to IAP. Deposition fractions were calculated using Multiple Particle Path Dosimetry (MPPD) to study the deposition patterns in different parts of the human respiratory tract (HRT) - head, tracheobronchial and pulmonary for women, young children and the elderly people. Dosage of particulate matter was calculated by inputting the recorded PM measurements, a comparison made for biomass-LPG and dosage intensification due to the kitchen-type presented. While the biomass households exhibited high levels of dosage (1181.4 to 5891.7 μg) against the LPG households (89.9 to 811.2 μg), the indoor kitchen types exhibited a maximum intensification of 10.6 times than outdoor kitchens with the same fuel. This study not only establishes the IAP characteristics but also quantifies the role of fuel-type and kitchen-type in IAP. The study also indicates various measures that could be deployed to reduce dosage and thus minimize the health risks., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Particulate matter (PM) is crucial among six criteria air pollutants, and it is frequently associated with human morbidity and mortality. According to the aerodynamic diameter, PM is classified as coarse (PM 10 ) and fine (PM 2.5 ). PM with these smaller sizes can easily enter and get deposited in the human airways. This deposited PM fraction commences the development of respiratory diseases such as asthma, chronic obstructive pulmonary disease, and even cancer. Thus, the quantification of PM deposition and its clearance in the human airway are essential for evaluating health risks. This study aims to investigate the size-segregated PM (PM 10 , PM 2.5, and PM 1 ) deposition in human lungs. Size-segregated PM is collected using the Grimm portable environmental dust monitor during winter season near an arterial road located in Chennai city of Tamil Nadu state, India. Multiple-Path Particle Dosimetry (MPPD) Model version 3.04 is utilized for quantifying PM deposition. In MPPD, airway structures of infants (3 and 28 months), children (3, 8, 9 and 14 years) and adults (18 and 21 years) are considered for the study. The values of PM concentration, body orientation, breathing scenario, tidal volume, pause fraction, inspiration fraction, and breathing frequency are specified in the MPPD for quantifying PM depositions. Results showed that 8-year children and 28 months infant groups are recorded with maximum and minimum size-segregated PM deposition respectively. The coarse particles (PM 10 ) are primarily deposited in the head (55-95%) and tracheobronchial (3-44%) regions whereas fine particles (PM 2.5 and PM 1 ) depositions are observed maximum in the head (36-63%) and pulmonary (28.2-52.7%) regions. Except for the adult age group, PM 2.5 has the maximum deposition percentage in tracheobronchial and pulmonary regions. In the case of lobar depositions, lower lobes receive maximum deposition (66.4%) than the upper (27.2%) and middle lobes (6.4%). PM 2.5 dominated the deposition in all five lobes of infant, children, and adults. The clearance rate of deposited PM is high in the tracheobronchial region whereas it is low in the pulmonary region. This study also concludes that PM 2.5 is the important size fraction in lung deposition. Further, the study results can be used for human health risk assessments such as oxidative potential and toxicity of deposited PM., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Impairment in mitochondrial biogenesis and function plays a key role in depression and anxiety, both of which being associated with changes in fatty acid and phospholipid metabolism. The antidepressant effects of (R,S)-ketamine have been linked to its conversion into (2S,6S;2R,6R)-hydroxynorketamine (HNK); however, the connection between structure and stereochemistry of ketamine and HNK in the mitochondrial homeostatic response has not yet been fully elucidated at a metabolic level., Methods: We used a multi-platform, non-targeted metabolomics approach to study the change in mitochondrial metabolome of PC-12 cells treated with ketamine and HNK enantiomers. The identified metabolites were grouped into pathways in order to assess global responses., Results: Treatment with (2R,6R)-HNK elicited the significant change in 49 metabolites and associated pathways implicated in fundamental mitochondrial functions such as TCA cycle, branched-chain amino acid biosynthetic pathway, glycoxylate metabolic pathway, and fatty acid β-oxidation. The affected metabolites included glycerate, citrate, leucine, N,N-dimethylglycine, 3-hexenedioic acid, and carnitine and attenuated signals associated with 9 fatty acids and elaidic acid. Important metabolites involved in the purine and pyrimidine pathways were also affected by (2R-6R)-HNK. This global metabolic profile was not as strongly impacted by treatment with (2S,6S)-HNK, (R)- and (S)-ketamine and in some instances opposite effects were observed., Conclusions: The present data provide an overall view of the metabolic changes in mitochondrial function produced by (2R,6R)-HNK and related ketamine compounds and offer an insight into the source of the observed variance in antidepressant response elicited by the compounds., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Increasing urban air pollution level in Indian cities is one of the major concerns for policy makers due to its impact on public health. The growth in population and increase in associated motorised road transport demand is one of the major causes of increasing air pollution in most urban areas along with other sources e.g., road dust, construction dust, biomass burning etc. The present study documents the development of an urban local air quality management (ULAQM) framework at urban hotspots (non-attainment area) and a pathway for the flow of information from goal setting to policy making. The ULAQM also includes assessment and management of air pollution episodic conditions at these hotspots, which currently available city/regional-scale air quality management plans do not address. The prediction of extreme pollutant concentrations using a hybrid model differentiates the ULAQM from other existing air quality management plans. The developed ULAQM framework has been applied and validated at one of the busiest traffic intersections in Delhi and Chennai cities. Various scenarios have been tested targeting the effective reductions in elevated levels of NO x and PM 2.5 concentrations. The results indicate that a developed ULAQM framework is capable of providing an evidence-based graded action to reduce ambient pollution levels within the specified standard level at pre-identified locations. The ULAQM framework methodology is generalised and therefore can be applied to other non-attainment areas of the country., (Copyright © 2017 Elsevier B.V. All rights reserved.)

G protein-coupled receptor 55 (GPR55) possesses pro-oncogenic activity and its function can be competitively inhibited with (R,R')-4'-methoxy-1-naphthylfenoterol (MNF) through poorly defined signaling pathways. Here, the anti-tumorigenic effect of MNF was investigated in the human pancreatic cancer cell line, PANC-1, by focusing on the expression of known cancer biomarkers and the expression and function of multidrug resistance (MDR) exporters such as P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP). Incubation of PANC1 cells with MNF (1μM) for 24h significantly decreased EGF receptor, pyruvate kinase M2 (PKM2), and β-catenin protein levels and was accompanied by significant reduction in nuclear accumulation of HIF-1α and the phospho-active forms of PKM2 and β-catenin. Inhibition of GPR55 with either MNF or the GPR55 antagonist CID 16020046 lowered the amount of MDR proteins in total cellular extracts while diminishing the nuclear expression of Pgp and BCRP. There was significant nuclear accumulation of doxorubicin in PANC-1 cells treated with MNF and the pre-incubation with MNF increased the cytotoxicity of doxorubicin and gemcitabine in these cells. Potentiation of doxorubicin cytotoxicity by MNF was also observed in MDA-MB-231 breast cancer cells and U87MG glioblastoma cells, which express high levels of GPR55. The data suggest that inhibition of GPR55 activity produces antitumor effects via attenuation of the MEK/ERK and PI3K-AKT pathways leading to a reduction in the expression and function of MDR proteins., (Published by Elsevier Ltd.)

Screening approaches adopted in pharmaceutical companies for chiral LC method development may be quite complicated and sophisticated in order to guarantee a high success rate. However in other environments it may be of more value to assess how simple a screen might be used to still have a good chance of achieving success. The genuine need to develop chiral separations for the former 'legal-high' drug mephedrone and related cathinones of topical interest presented a good opportunity to develop this theme. In initial work on mephedrone itself, no chiral separation was observed on Chirobiotic V, Cyclobond I 2000 DNP, Whelk-O1 and AmyCoat using reversed phase mobile phases. However, using normal phase solvents, chiral separation was observed on all the chiral stationary phases (CSP) used except Chiralcel OJ-H. Of the chiral separations observed on RegisPack, RegisCell and Whelk-O1, some optimisation work was carried out on the latter two which had showed the greatest enantioselectivity. Following optimisation, the best enantioselectivity (1.59) and enantioresolution (5.90) was found with a 250 mm × 4.6 mm I.D. Whelk-O1 column using a propan-2-ol (IPA)-hexane-trifluoroacetic acid (TFA)-triethylamine (TEA) (10:90:0.05:0.05, v/v/v/v) mobile phase. Subsequent screening on other cathinones was restricted to RegisPack, RegisCell and Whelk-O1 or equivalent phases with two mobile phases and this gave a very good success rate. Indeed it was possible to separate all six cathinones on one column, RegisCell, with one mobile phase, propan-2-ol-hexane-TFA (15:85:0.1, v/v/v) but obviously it had been necessary to go through the 3-column screen to arrive at this finding. While Whelk-O1 was not so successful, ease of optimisation on this phase was again a feature. To illustrate the applicability of these separations, it was shown that, as a basis for semi-preparative work, the optimsed mephedrone separation on Whelk-O1 could be scaled-up to a 2000μl injection of a 1.0 mg ml(-1) solution in mobile phase (2.0mg on-column) while still using the 250 mm × 4.6 mm I.D. analytical column., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The 24-h average ambient particulate matter (PM(10) and PM(2.5)) concentrations are sampled concurrently during November 2008-April 2009 at a busy roadside in Chennai City, India. The elemental (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn) and ionic (Na(+), NH(4)(+), K(+), Ca(2+), Mg(2+), F(-), Cl(-), NO(2)(-), NO(3)(-) and SO(4)(2-)) composition of PM(10) and PM(2.5) are determined using an inductively coupled plasma-optical emission spectrometer (ICP-OES) and an ion chromatograph (IC), respectively. The emission inventory at the study area is also carried out to identify the likely PM emission sources. The U.S. EPA's-CMB (chemical mass balance) version 8.2 is applied to identify the source contribution of ambient PM(10) and PM(2.5) concentrations at the study area. Results indicated that diesel exhausts (43-52% in PM(10) and 44-65% in PM(2.5)) and gasoline exhausts (6-16% in PM(10) and 3-8% in PM(2.5)) are found to be the major source contributors at the study site followed by the paved road dusts (PM(10)=PM(2.5)=0.-2.3%), brake lining dusts (0.1% in PM(10) and 0.2% in PM(2.5)), brake pad wear dusts (0.1% in PM(10) and 0.01% in PM(2.5)), marine aerosols (PM(10)=PM(2.5)=0.1%) and cooking (~0.8% in PM(10) and ~1.5% in PM(2.5))., (Copyright © 2012 Elsevier B.V. All rights reserved.)

An enantioselective capillary electrophoresis-laser-induced fluorescence (CE-LIF) method for the analysis of D-serine (D-Ser) in cellular matrices has been developed. The assay involves derivatization with FITC followed by CE-LIF using 0.5 mM hydroxyl propyl-β-cyclodextrin in borate buffer [80 mM, pH 9.3]. The method was able to resolve D-Ser and L-Ser with an enantioselectivity (α) of 1.03 and a resolution (R(s)) of 1.37. Linearity was established from 0.25 to 100.00 μM. The assay was also able to enantioselectively resolve 6 additional amino acid racemates. The method was applied to the determination of intracellular D-Ser concentrations in PC-12, C6, 1312N1, and HepG2 cell lines. This method was used to determine the concentration-dependent increases in D-Ser and associated EC₅₀ values produced by L-Ser and the concentration-dependent decreases in d-Ser and associated IC₅₀ values produced by glycine, a competitive inhibitor of serine racemase (SR). Western blot analysis determined that the PC-12 and C6 cell lines contained monomeric and dimeric forms of SR while the 1321N1 and HepG2 cells contained only the monomeric form. Although the SR dimer has been identified as the active form of the enzyme, all four of the tested cell lines expressed enzymatically active SR., (Published by Elsevier Inc.)

In this paper, the chemical characterization of PM₁₀ and PM₂.₅ mass concentrations emitted by heterogeneous traffic in Chennai city during monsoon, winter and summer seasons were analysed. The 24-h averages of PM₁₀ and PM₂.₅ mass concentrations, showed higher concentrations during the winter season (PM₁₀=98 μg/m³; PM₂.₅=74 μg/m³) followed by the monsoon (PM₁₀=87 μg/m³; PM₂.₅=56 μg/m³) and summer (PM₁₀=77 μg/m³; PM₂.₅=67 μg/m³) seasons. The assessment of 24-h average PM₁₀ and PM₂.₅ concentrations was indicated as violation of the world health organization (WHO standard for PM₁₀=50 μg/m³ and PM₂.₅=25 μg/m³) and Indian national ambient air quality standards (NAAQS for PM₁₀=100 μg/m³ and PM₂.₅=60 μg/m³). The chemicals characterization of PM₁₀ and PM₂.₅ samples (22 samples) for each season were made for water soluble ions using Ion Chromatography (IC) and trace metals by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) instrument. Results showed the dominance of crustal elements (Ca, Mg, Al, Fe and K), followed by marine aerosols (Na and K) and trace elements (Zn, Ba, Be, Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, Sr and Te) emitted from road traffic in both PM₁₀ and PM₂.₅ mass. The ionic species concentration in PM₁₀ and PM₂.₅ mass consists of 47-65% of anions and 35-53% of cations with dominance of SO₄²⁻ ions. Comparison of the metallic and ionic species in PM₁₀ and PM₂.₅ mass indicated the contributions from sea and crustal soil emissions to the coarse particles and traffic emissions to fine particles., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A case report of 37-year-old female with end stage renal disease presented with recurrent pericardial effusion and cardiac tamponade, who underwent percutaneous balloon pericardiotomy using an Inoue balloon dilating catheter, to create a non-surgical pericardial window. The procedure of non-surgical pericardial window is safe and effective alternative to conventional more invasive surgical pericardial window. It is concluded that percutaneous balloon pericardiotomy is helpful in the management of massive pericardial effusions particularly in patients with chronic renal failure and poor clinical condition.

DNA sequences encoding hypothetical proteins homologous to S1 nuclease from Aspergillus oryzae are found in many organisms including fungi, plants, pathogenic bacteria, and eukaryotic parasites. One of these is the M1 nuclease of Mesorhizobium loti which we demonstrate herein to be an enzymatically active, soluble, and stable S1 homolog that lacks the extensive mannosyl-glycosylation found in eukaryotic S1 nuclease homologs. We have expressed the cloned M1 protein in M. loti and purified recombinant native M1 to near homogeneity and have also isolated a homogeneous M1 carboxy-terminal hexahistidine tag fusion protein. Mass spectrometry and N-terminal Edman degradation sequencing confirmed the protein identity. The enzymatic properties of the purified M1 nuclease are similar to those of S1. At acidic pH M1 is 25 times more active on single-stranded DNA than on double-stranded DNA and 3 times more active on single-stranded DNA than on single-stranded RNA. At neutral pH the RNase activity of M1 exceeds the DNase activity. M1 nicks supercoiled RF-I plasmid DNA and rapidly cuts the phosphodiester bond across from the nick in the resultant relaxed RF-II plasmid DNA. Therefore, M1 represents an active bacterial S1 homolog in spite of great sequence divergence. The biochemical characterization of M1 nuclease supports our sequence alignment that reveals the minimal 21 amino acid residues that are necessarily conserved for the structure and functions of this enzyme family. The ability of M1 to degrade RNA at neutral pH implies previously unappreciated roles of these nucleases in biological systems.

Background: Complex anatomy of intra-cardiac structures requires spatial orientation of image in three dimensions for better understanding and enhanced image interpretation. We evaluated the feasibility and efficacy of the emerging 'real-time three-dimensional transthoracic echocardiography' technique for comprehensive assessment of cardiac anatomy, physiology, pathomorphology and pathophysiology in patients with structural heart disease., Methods and Results: Patients with structural heart disease (n=152) were evaluated by conventional two-dimensional transthoracic echocardiography and real-time three-dimensional transthoracic echocardiography using standard protocol. Fifty-six cases were of rheumatic etiology with multi-valvular involvement (mitral stenosis: 32; mitral regurgitation: 29; tricuspid regurgitation: 8; aortic valve disease: 11) and 21 cases of non-rheumatic valvular heart disease. A total of 38 congenital heart disease patients were examined including 23 patients with atrial septal defect. Left ventricular function (n=20) and right ventricular function (n=10) were also assessed using dedicated software., Conclusions: Results of real-time three-dimensional transthoracic echocardiography mitral valve area assessment by planimetery are comparable to two-dimensional transthoracic echocardiography with additional information about surface anatomy of leaflets and the subvalvular apparatus in real time with clear demarcation of commissural fusion and scallops of leaflets. Enface view of atrial septal defect with direct visualization of shape, size and number of defects, tricuspid valve area by planimetery, right ventricular shape, objective assessment of ventricular volumes and regurgitation vena contracta area are the fields where three-dimensional transthoracic echocardiography was of additive value to conventional two-dimensional transthoracic echcardiography. This study proves clinical feasibility of real-time three-dimensional transthoracic echocardiography but requires further validation of quantitative observations.

Differential development of monoamine oxidase (MAO) isoenzymes in rat whole brain is described in postnatally developing Sprague-Dawley rats. Total MAO and isoenzyme activity was measured using nonspecific and specific substrates. Total MAO activity measured using tyramine, increased postnatally up to 24 weeks of age and attained a plateau afterward. The increase in total MAO activity was significant at all age groups (18 days to 36 months) investigated as compared to new born rats. MAO-A and MAO-B activities were measured using octopamine and benzylamine respectively. We also observed a marginal increase of MAO-A activity and a significant increase of MAO-B activity upon development. Furthermore, at 12 weeks of age, MAO-B activity increased by 10-fold as compared to new born and was consistent up to 36 months of age. The qualitative localization of the enzyme activity on non SDS-PAGE by nitroblue tetrazolium staining confirmed the increase of MAO-B during the development. It is suggested that the maturational increase of total MAO activity in brain is predominantly due to the increase of MAO-B isoenzyme.

Experiments were carried out to establish the role of glutathione reductase (GR), if any, in the metabolic conversion of disulfiram (DS) to diethyldithiocarbamate (DDC). It was observed that, under standard assay conditions, whereas DS was incorporated as a substrate instead of oxidised glutathione (GSSG), the enzymes from both human liver extract and yeast sources failed to reduce the parent compound, implying that glutathione reductase perse do not reduce disulfiram. However, the incorporation of disulfiram into an assay system comprising of GSSG, NADPH and reductase resulted in DS reduction to DDC. Further, the observation, that the GR assay system devoid of either GSSG or NADPH was found to lack DS reducing ability, implies that GSH as a reaction product of GR system is responsible for the reduction of DS to DDC. The results of in-vitro experiments indicated that GSH perse could reduce DS to DDC nonenzymatically, with a stoichiometric relationship of 2:1. Thus it is inferred that GR perse do not reduce DS, whereas GSH, as an intermediary metabolite of GR system, brings about non-enzymatic reduction of DS via a sulfhydral group exchange reaction.