Large Scale Synthesis of Binary Composite Nanowires in the Mn2O3-SnO2 System with Improved Charge Storage Capabilities

Large scale production of electrochemical materials in non-conventional morphologies such as nanowires has been a challenging issue. Besides, functional materials for a given application do not often offer all properties required for ideal performance; therefore, a composite is the most sought remedy. In this paper, we report large scale production of a composite nanowire, viz. Mn2O3-SnO2, and their constituent binary nanowires by a large scale electrospinning pilot plant consisting of 100 needles. Electrochemical characterization of thus produced composite nanowires showed nearly threefold increase in the discharge capacity compared to their single component counterparts: Mn2O3-SnO2 ∼53 mA h g−1 (specific capacitance, CS ∼384 F g−1); Mn2O3 ∼18 mA h g−1 (CS ∼164 F g−1); and SnO2 ∼14 mA h g−1 (CS ∼128 F g−1) at 1 A g−1 in 6 M KOH. The EIS studies showed that the characteristic resistances and time of the composite electrode are appreciably lower than their constituents. Owing to the scalability of the synthesis processes and promising capacitive properties achieved would lead the composite material as a competitive low-cost and high-performance supercapacitor electrode

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Function of flotillins in Alzheimer disease and apoptosis

Alzheimer’s disease (AD) is a common, age associated neurodegenerative disease that manifests as progressive dementia and is characterized by accumulation of the amyloid beta (Aβ) peptide which is a processing product of a transmembrane protein termed Alzheimer Amyloid Precursor Protein (APP). The Aβ peptide is generated by a sequential proteolytic processing of APP by two distinct proteases that are termed β- and γ-secretase. The β-secretase, also called BACE-1 or memapsin 2, belongs to the family of aspartyl proteases. BACE-1 evidently cleaves APP in an acidic endosomal compartment after endocytosis of APP, thereby facilitating Aβ peptide generation. Sorting of transmembrane proteins is generally controlled by sorting signals in the cytoplasmic domains of the cargo proteins. The short cytoplasmic tail of BACE-1 with 23 amino acids contains a sorting signal of the acidic cluster, di-leucine (ACDL) type. The two Leu residues in this determinant are important for the clathrin mediated endocytosis of BACE-1, whereas the acidic residues together with the Leu are required for the endosomal sorting and recycling of BACE-1 back to the plasma membrane. The ACDL motif binds to the members of the GGA (Golgi-localized γ ear-containg ARF- binding proteins) family (GGA1-GGA3) that are involved in the sorting of BACE-1. One of the major aims of this study was to address the role of flotillins in the intracellular sorting of BACE-1. This study shows that flotillin-1 directly binds to the di-leucine motif in the cytoplasmic tail of BACE-1, whereas flotillin-2 only shows an association mediated by flotillin-1. Flotillin-1 competes with GGA2 for the binding to BACE-1 tail, and thus influences the endosomal sorting of BACE-1. Importantly, depletion of flotillins results in an altered localization of the wildtype BACE-1, whereas the plasma membrane resident Leu to Ala (LLAA) mutant is not affected. Flotillin knockdown results in an accumulation of BACE-1, implicating reduced degradation and enhanced stability of this protease. Thus, flotillins appear to be important for the cellular targeting of BACE-1 and also influence the amyloidogenic processing of APP, as demonstrated by an increase in the amyloidogenic C-99 processing fragments. When flotillin depleted cells were subjected to apoptotic stresses including Aβ25-35 synthetic peptide (inducer of the extrinsic apoptosis pathway) or several chemotherapeutic agents (staurosporine, brefeldin A, doxorubicin, carboplatin and paclitaxel: intrinsic apoptosis pathway) and cytotoxicity was determined, various apoptotic markers were activated in flotillin depleted cells. Caspase-3 and GGA3 are well accepted apoptosis markers and an enhanced caspase-3 cleavage was detected upon STS induced apoptosis in SH-SY5Y, HeLa, and HaCaT cell lines and increased GGA3 cleavage was observed in MCF7 cell line. One of the major reasons for the apoptotic sensitivity in the absence of flotillins was a PI3K/Akt signaling defect. Neuroblastoma cells depleted of flotillins showed diminished levels of total Akt, phospho-Akt and phospho-ERK upon STS induced apoptosis. Since PI3K/Akt was the primary survival pathway affected upon STS induced apoptosis, ectopic expression of Akt in neuroblastoma cell line reduced caspase-3 cleavage and retarded apoptosis. The direct downstream target of Akt is FOXO3a, whose localization was investigated in flotillin depleted cells. A major proportion of FOXO3a was localized in the nucleus of flotillin knockdown cells, implicating that FOXOs are active in these cells and subsequently trigger the transcription of death genes. Strikingly, an essential anti-apoptotic molecule and a major cancer target, Mcl-1, was inherently downregulated in flotillin knockdown cells. Mcl-1 is a chief member of the Bcl-2 family as it plays a pivotal role in cell survival and it is a critical protein in cancer therapeutics as suppression of Mcl-1 protein can curtail the survival and growth of tumorous cells. Neuroblastoma cells were rescued from undergoing permanent damage due to STS induced apoptosis by overexpression of anti-apoptotic Bcl-2. Phorbol esters are well known PKC activators, and pre-treatment of neuroblastoma cells with phorbol esters along with staurosporine reduced caspase-3 cleavage. These results demonstrate that absence of flotillins can sensitize cellular systems to apoptosis induction. The two main characteristics of cancer cells include resistance to apoptosis and unresponsiveness to chemotherapeutic agents. It is a well established fact that impaired apoptosis is central to tumour development. This study implicates that the downregulation of flotillin function can trigger cellular susceptibility and enhances apoptosis in response to conventional chemotherapeutic agents. Therefore, flotillins can serve as vital regulators in providing a more rational approach in molecular-targeted therapies for receding cancer growth and survival

Imidazolidine-2-thione as corrosion inhibitor for mild steel in hydrochloric acid

366-374The inhibition effect of imidazolidine-2-thione (IMT) on the corrosion behaviour of mild steel (MS) in 1 N HCl was studied using potentiodynamic polarization, linear polarisation resistance (LPR), electrochemical impedance spectroscopy (EIS) and adsorption studies. The effects of inhibitor concentrations, temperature, corrosion rate and surface coverage are investigated. The corrosion rate and other parameters are evaluated for different inhibitor concentrations and the probable mechanism is also proposed. The results show that IMT possesses excellent inhibiting effect for the corrosion of the MS and the inhibitor acts as a mixed type inhibitor. The inhibitor does not affects the mechanism of the electrode processes and inhibits corrosion by blocking the reaction sites. The high inhibition efficiency of IMT was due to the adsorption of inhibitor molecules on the metal surface. The decrease of surface area available for electrode reactions to take place is due to the formation of a protective film. Activation energies and enthalpies of activation in the presence and absence of IMT were determined by measuring the temperature dependence of the corrosion current

Spectrophotometric determination of osmium(VIII) in trace amounts using ethylene thiourea (ETU) as chromogenic reagent

113-117A simple and highly sensitive spectrophotometric method has been described for the determination of trace amount of osmium(VIII) using ethylene thiourea (ETU) as a chromogenic reagent. The method is based on the formation of an instantaneous purple coloured complex at room temperature by the reaction of osmium(VIII) with ETU in strongly acidic (pH=1) solution having absorption maximum at 490 nm and is confirmed using derivative spectrophotometry. Linear calibration graphs are obtained for 0.03-3 µg/mL of the analyte. Sandell's sensitivity (1.13×10-3 µgcm-2), molar absorptivity (16.87×104 Lmol-1 cm-1), detection limit (0.0291 µg/mL) and quantitation limit (0.0833 µg/mL) are also calculated. The method is optimized and different analytical parameters were evaluated. The stoichiometry of the complex is found to be 1:3 by Job's method and mole ratio method. The stoichiometry of the complex is further confirmed by synthesizing the solid compound and characterizing it by various physicochemical methods