Environmental and social disclosures dataset for Malaysian public listed companies.

This article presents a comprehensive dataset extracted from published annual, sustainability and integrated reports, focusing on environmental (GRI300) and social (GRI400) disclosures, for the top 100 Malaysian public listed companies (based on Market Capitalization as of 31 December 2016). The dataset covers three years (2018 to 2020) with 300 firm-year observations. Environmental and Social disclosure scores were calculated using the Global Reporting Initiative (GRI) framework and derived from the content analysis of the companies' reports accessed from respective corporate or Bursa Malaysia's websites. A binary scoring method (one for disclosure or zero, otherwise for each environmental and social disclosure item) was employed. This scoring process underwent three stages of rigorous manual verification protocol: initial check and scoring by research assistants, review by the research team, and a final review by an independent external accounting firm for validation. This dataset is valuable for academics, practitioners, and policymakers to evaluate corporate alignment with UN Sustainable Development Goal (SDG) #12, encouraging Responsible Consumption and Production, and shape strategic policies to meet Bursa compliance for enhanced corporate sustainability. It further aids in investigating associations between governance factors and other firm characteristics with environmental and social disclosures.

An enhanced electrochemical performance of in milk, pigeon meat and eggs samples using se nanorods capped with Co3O4 nanoflowers decorated on graphene oxide.

In this work, we report a novel preparation of selenium nanorods (Se) doped cobalt oxide (Co3O4) nanoflowers encapsulated with graphene oxide (GO) nanocomposite (NC). Se nanorods were successfully decorated on Co3O4 nanoflowers and an increase in electrical conductivity was observed in Se-Co3O4@GO-NC. The as-prepared Se-Co3O4@GO-NC was utilized as an effective nanocomposite for the electrochemical detection of dimetridazole (DMZ) for the first time in the field of electrochemical sensors. Se-Co3O4@GO-NC modified glassy carbon electrode (GCE) which showed an excellent cathodic current response (17.6 µA) at the lower potential at -0.7314 V upon DMZ sensing. With the various optimized conditions, Se-Co3O4@GO-NC based electrochemical sensor displayed a lengthy linear range of 0.02-83.72 µM, limit of detection 3.4 nM and sensitivity of 1.898 µA.µM-1. cm-2 for DMZ detection. In addition, Se-Co3O4@GO-NC revealed fabulous catalytic reduction activity for DMZ, when compared to GO and Se-Co3O4 modified GCE. Additionally, Se-Co3O4@GO-NC is applied in real sample analysis of pigeon egg, milk and pigeon meat. The results illustrated that Se-Co3O4@GO-NC can be a promising nanocomposite for the electrocatalytic reduction of DMZ in clinical samples in biomedical field.

Microfluidic electrochemical immunosensor for the determination of cystatin C in human serum.

The fabrication of a nanointerfaced electrochemical immunosensor is described for the rapid determination of cystatin C, a biomarker that is elevated in diabetic retinopathy. A dispersion of graphene oxide-chitosan (GO-Chit) nanocomposite was used to modify the carbon working electrode, allowing for a high conjugation of anti-cystatin C antibody. This modified sensor was characterized both morphologically and electrochemically, and the sensor performance was evaluated towards selective quantification of cystatin C in simulated as well as serum samples using cyclic voltammetry and differential pulse voltammetry. The sensor was able to detect cystatin C in the concentration range1 - 10 mg/L with a detection limit of 0.0078 mg/L. The preparation time of the sensor was 420 s, which was faster than that of conventional ELISA and other electrochemical sensors reported in literature. The clinical applicability of the proposed electrochemical biosensor was demonstrated through quantification of cystatin C in human serum samples and identification of diabetic retinopathy. A cutoff value of 1.2 mg/L of cystatin C was used beyond which the samples were classified as positive for diabetic retinopathy. Two different working electrodes, namely a glassy carbon electrode (GCE) and paper electrodes, were used in the study. The working potential was set to 0.25 V vs. Ag/AgCl for experiments with the GCE and 0.15 V for the paper electrodes. The prediction was validated by clinical diagnosis wherein the prediction accuracy of the sensor exceeded 85%. The sensor platform was translated onto a paper substrate and characterized for achieving an optimum sensing performance. This work is the first attempt to employ an electrochemical cystatin C sensor for the diagnosis of diabetic retinopathy from serum samples. Graphical abstract.

Vitamin B12-Immobilized Graphene Oxide for Efficient Electrocatalytic Carbon Dioxide Reduction Reaction.

A naturally occurring water-soluble cobalt-complex cyanocobalamin (Vitamin B12) has been identified as a new and efficient electrocatalyst for the CO2 -to-CO reduction reaction in aqueous solution. Heterogeneous B12-electrocatalysts prepared by a simple electrochemical immobilization technique on graphene-oxide (GO)-modified glassy carbon and carbon paper (CP) electrodes, without any non-degradable polymer-binders, showed a highly stable and well-defined surface-confined redox peak at E'=-0.138 V vs. RHE with a surface-excess value, ΓB12 =4.28 nmol cm-2 . This new electrocatalyst exhibits 93 % Faradaic efficiency for CO2 -to-CO conversion at an electrolysis potential, -0.882 V vs. RHE (an optimal condition) with a high current density, 29.4 mA cm-2 and turn-over-frequency value, 5.2 s-1 , without any surface-fouling problem, in 0.5 m KHCO3 . In further, it follows an eco-friendly, sustainable and water-based approach with the involvement of biodegradable and non-toxic chemicals/materials like B12, GO and CP.

Nickel sulfide-incorporated sulfur-doped graphitic carbon nitride nanohybrid interface for non-enzymatic electrochemical sensing of glucose.

A nickel sulfide-incorporated sulfur-doped graphitic carbon nitride (NiS/S-g-C3N4) nanohybrid was utilized as an interface material for the non-enzymatic sensing of glucose in an alkaline medium (0.1 M NaOH). The precursors used in the preparation of NiS/S-g-C3N4 hybrid were thiourea and nickel nitrate hexahydrate as the sulfur and nickel sources, respectively. The HRTEM results reveal that NiS nanoparticles incorporated on the S-g-C3N4 nanosheet surface could enhance the electrocatalytic activity and electrical conductivity. The prepared NiS/S-g-C3N4 crystalline nature, surface functionalities, graphitic nature, thermal stability and surface composition were investigated using XRD, FT-IR, Raman spectroscopy, TGA and XPS analyses. The NiS/S-g-C3N4 modified electrode was used for the non-enzymatic sensing of glucose at an applied potential of 0.55 V vs. Ag/AgCl with a detection limit of 1.5 µM (S/N = 3), sensitivity of 80 µA mM-1 cm-2 and the response time of the fabricated sensor was close to 5 s. Different inorganic ions and organic substances did not interfere during glucose sensing. The NiS/S-g-C3N4 nanohybrid material could be extended for a real sample analysis and open the way for diverse opportunities in the electrochemical sensing of glucose.

Metabolic Syndrome-An Emerging Constellation of Risk Factors: Electrochemical Detection Strategies.

Metabolic syndrome is a condition that results from dysfunction of different metabolic pathways leading to increased risk of disorders such as hyperglycemia, atherosclerosis, cardiovascular diseases, cancer, neurodegenerative disorders etc. As this condition cannot be diagnosed based on a single marker, multiple markers need to be detected and quantified to assess the risk facing an individual of metabolic syndrome. In this context, chemical- and bio-sensors capable of detecting multiple analytes may provide an appropriate diagnostic strategy. Research in this field has resulted in the evolution of sensors from the first generation to a fourth generation of 'smart' sensors. A shift in the sensing paradigm involving the sensing element and transduction strategy has also resulted in remarkable advancements in biomedical diagnostics particularly in terms of higher sensitivity and selectivity towards analyte molecule and rapid response time. This review encapsulates the significant advancements reported so far in the field of sensors developed for biomarkers of metabolic syndrome.

Achieving a Stable High Surface Excess of Glucose Oxidase on Pristine Multiwalled Carbon Nanotubes for Glucose Quantification.

In this study, glucose oxidase (GOx) immobilization onto ten different types of carbon modified GCEs and its direct electron transfer (DET) were investigated. A maximum amount of GOx immobilization (ΓGOx) of 2.9 nM/cm2 was achieved on the pristine multiwalled carbon nanotubes (PMWCNT) with high stability. Furthermore, the coefficient value for electron transfer (0.5) and the rate constant of 3.16 s-1 were measured from scan rate studies on PMWCNT/GOx. The derived electro-analytical parameters were superior in PMWCNT system than those of several CNT based nanocomposite materials published in the literature. The PMWCNT/GOx displayed a standard potential (E0') of -444 mV with perfect redox peaks, and appreciable peak separation (ΔEp) value of 22 mV in neutral electrolyte medium was noted. Glucose quantification was made using the mediator, ferrocene monocarboxylic acid (FMCA), and quantification was done with dissolved oxygen (O2) reduction caused by the glucose oxidase-mediated enzymatic catalysis of glucose. Sensor calibration results revealed a broad range from 0.2 to 5.8 mM with a lower limit of determination found to be 45 µM for glucose. A strong affinity between PMWCNT/GOx and glucose was assessed with Michaelis-Menten constant (2.24 mM). The proposed biosensor had excellent sensitivity and remained unaffected by the presence of other electroactive groups. This work demonstrates that pristine MWCNT can be used directly as an immobilization matrix for biosensing applications without cumbersome electrode preparation steps and the introduction of dopants.

Synthesis, Characterization, and Biomedical Applications of an Alkylated Quercetin-Gadolinium Complex.

Flavonoids and their derivatives have been extensively studied for their pharmaceutical applications due to their antioxidant and anti-inflammatory properties. The coordination complexes of several flavonoids have demonstrated DNA binding ability that can confer anticancer properties. The structure of the flavonoid has a pronounced influence on its pharmacological properties. Herein we report the synthesis and characterization of alkylated quercetin and its complex with gadolinium. The structure of the complex was confirmed using spectroscopic techniques. The ability of the gadolinium-alkylated quercetin complex to serve as a magnetic contrast agent was compared with gadolinium-quercetin complex. The quercetin-gadolinium complex was found to exhibit better contrast property with a relaxivity of 0.2952 µg mL-1 s-1 when compared to the gadolinium complex of alkylated quercetin. This difference primarily arises due to the greater hydrophobicity of the alkylated quercetin complex that restricts access of water. However, the alkylated quercetin was found to exhibit better enzyme mimic activity as the metal ion served as a redox center that enabled quantification of hydrogen peroxide in the concentration range 50-450 µM within 5 s with a sensitivity of 64 nA/µM and limit of detection of 7.3 µM. The better sensing performance of the alkylated quercetin-gadolinium complex, reported here for the first time, when compared to quercetin-gadolinium complex can be attributed to the enhanced electroactive area on the working electrode.

A blood-serum sulfide selective electrochemical sensor based on a 9,10-phenanthrenequinone-tethered graphene oxide modified electrode.

The sulfide ion and its associated species (H2S and HS-) are widely referred to as toxic chemicals. However, at concentrations of ∼10-100 µM, it serves as a neurotransmitter and signaling agent in biological systems. Abnormalities in blood serum sulfide can be an indication of several diseases, including diabetes, wherein there is a significant reduction in the sulfide ion concentration (<10 µM). Herein, we wish report a 9,10-phenanthrenequinone (PQn) tethered graphene oxide (GO) modified glassy carbon electrode (GCE/GO@PQn) for the highly selective and stable electrocatalytic oxidation and flow injection analysis (FIA) of sulfide ions. The electrode exhibits a detection range of 1-100 µM, and is suitable for the common biochemical interference-free detection of blood serum sulfide in pH 7 phosphate buffer solution. The modified electrode was found to be tolerant of interfering chemicals such as cysteine, uric acid, ascorbic acid, nitrate, glucose, hydrogen peroxide, nitrate, nitrite and dissolved oxygen. This is unlike conventional redox mediator modified electrodes, which all show marked interference with the above-mentioned chemicals during sulfide detection. A constructed FIA calibration plot (applied potential, Eapp = 0.15 V vs. Ag/AgCl) was linear in the sulfide concentration ranges of 1-100 µM (1st region) and 300 µM-5 mM (2nd region) with a detection limit value of 700 nM. The selective and quick FIA of sulfide ions in three diabetic patient blood samples along with a control was demonstrated as a proof of concept.

In Situ Structural Elucidation and Selective Pb2+ Ion Recognition of Polydopamine Film Formed by Controlled Electrochemical Oxidation of Dopamine.

Owing to the versatility and biocompatibility, a self-polymerized DA (in the presence of air at pH 8.5 tris buffer solution) as a polydopamine (pDA) film has been used for a variety of applications. Indeed, instability under electrified condition (serious surface-fouling) and structural ambiguity of the pDA have been found to be unresolved problems. Previously, pDA films (has hygroscopic and insoluble property) prepared by various controlled chemical oxidation methods have been examined for the structural analysis using ex situ solid-state NMR and mass spectroscopic techniques. In this work, a new in situ approach has been introduced using an electrochemical quartz crystal microbalance (EQCM) technique for the improved structural elucidation of pDA that has been formed by a controlled electrochemical oxidation of DA on a carboxylic acid functionalized multiwalled carbon nanotube-Nafion (cationic perfluoro polymer) modified electrode (f-MWCNT-Nf) system in pH 7 phosphate buffer solution. Key intermediates like 5,6-dihydroxy indole (DHI; 150.7 g mol-1), dopamine (154.1 g mol-1), Na+, PO42-, and polymeric product of high molecular weight, 2475 g mol-1, have been trapped on f-MWCNT-Nf surface via π-π (sp2 carbon of MWCNT and aromatic e-s), covalent (amide-II bonding, minimal), hydrogen, and ionic bonding and identified its molecular weights successfully. The new pDA film system showed well-defined peaks at E°' = 0.25 V and -0.350 vs Ag/AgCl corresponding to the surface-confined dopamine/dopamine quinone and DHI/5,6-indolequinone redox transitions without any surface-fouling complication. As an electroanalytical application of pDA, selective recognition of Pb2+ ion via {(pDA)-hydroquinone-Pb0} complexation with detection limit (signal-to-noise ratio = 3) 840 part-per-trillion has been demonstrated.

An Elegant Analysis of White Spot Syndrome Virus Using a Graphene Oxide/Methylene Blue based Electrochemical Immunosensor Platform.

White spot syndrome virus (WSSV) is a major devastating virus in aquaculture industry. A sensitive and selective diagnostic method for WSSV is a pressing need for the early detection and protection of the aquaculture farms. Herein, we first report, a simple electrochemical immunosensor based on methylene blue dye (MB) immobilized graphene oxide modified glassy carbon electrode (GCE/GO@MB) for selective, quick (35 ± 5 mins) and raw sample analysis of WSSV. The immunosensor was prepared by sequential modification of primary antibody, blocking agent (bovine serum album), antigen (as vp28 protein), secondary antibody coupled with horseradish peroxidase (Ab2-HRP) on the GCE/GO@MB. The modified electrode showed a well-defined redox peak at an equilibrium potential (E1/2), -0.4 V vs Ag/AgCl and mediated H2O2 reduction reaction without any false positive result and dissolved oxygen interferences in pH 7 phosphate buffer solution. Under an optimal condition, constructed calibration plot was linear in a range of 1.36 × 10-3 to 1.36 × 107 copies µL-1 of vp28. It is about four orders higher sensitive than that of the values observed with polymerase chain reaction (PCR) and western blot based WSSV detection techniques. Direct electrochemical immunosensing of WSSV in raw tissue samples were successfully demonstrated as a real sample system.

Enhancing fermentable sugar yield from cassava pulp for bioethanol production: microwave-coupled enzymatic hydrolysis approach.

Cassava pulp, a potential biological feedstock for ethanol production has been subjected to microwave-assisted alkali pretreatment and microwave-coupled enzymatic hydrolysis. Microwave pretreatment may be a good alternative as it can reduce the pretreatment time and improve the enzymatic activity during hydrolysis. Liquid to solid ratio for the pretreatment of cassava pulp was found to be 20:1. Cassava pulp was pretreated at various NaOH concentration, microwave temperature and gave maximum yield of reducing sugar with 1.5% NaOH at 90 °C in 30 min than conventional alkali pretreatment after enzymatic hydrolysis. The subsequent enzymatic saccharification of pretreated cassava pulp using α amylase dosage of 400 IU at microwave temperature of 90 °C resulted in highest reducing sugar yield of 723 mg/g pulp. Microwave-assisted alkali pretreatment improved the enzymatic saccharification of cassava pulp by increasing its accessibility to hydrolytic enzymes. Microwave-assisted alkali pretreatment and microwave-coupled enzymatic hydrolysis are found to be efficient for improving the yield of reducing sugar.

A direct SAXS approach for the determination of specific surface area of clay in polymer-layered silicate nanocomposites.

The interfacial area between the matrix and the filler is a key parameter which shapes the performance of polymer-based composites and nanocomposites, even though it is difficult to quantify. A very easy SAXS method, based on the Porod equation, is proposed for measuring the specific surface area of nanofillers embedded in a polymer matrix. In order to assess its reliability, this approach was applied to natural rubber- or styrene butadiene-based samples containing different types of montmorillonite clay. A wide range of specific surfaces was detected. SAXS data were compared to complementary X-ray diffraction and TEM information, obtaining a good agreement. Interpretation of the tensile properties by theoretical models and comparison with the literature corroborated the validity of the specific surface area measurement. The possibility to quantify this feature of composites allows the rational design of such materials to be improved.

Emergence of sporotrichosis in Manipur.

A retrospective analysis of all cases of sporotrichosis was conducted to examine the pattern and frequency of sporotrichosis cases in Manipur over a period of six year from July 1999 to June 2005. Seventy-three (73) cases of sporotrichosis were detected of which 30 were confirmed by culture and 43 were diagnosed by aspiration cytology only. Most of the patients belonged to the age group of 21 to 40 years (n = 23; 31.5%). There were 39 females (53.4%) and 34 males (46.5%). Commonest site of infection was upper limbs (n = 39; 53.4%) followed by lower limbs (n = 17; 23.2%). Commonest type of infection was lymphocutaneous form (n = 46; 63.1%) followed by fixed cutaneous form (n = 27; 36.9%). Among these 73 cases, 2 male patients (2.7%) were found to be HIV positive. In our experience, collection of material by aspiration of pus or infected tissue was found to be a better method compared to scraping or exudate. This study revealed Manipur as a new endemic area for sporotrichosis.

Ecthyma gangrenosum: a rare cutaneous manifestation caused by pseudomonas aeruginosa without bacteraemia in a leukaemic patient--a case report.

Ecthyma gangrenosum is a rare and invasive cutaneous infection caused by Pseudomonas aeruginosa in the majority of cases, typically affecting immunocompromised patients, particularly those with neutropenia. We report a rare case of ecthyma gangrenosum in the absence of bacteraemia presenting as a solitary necrotic ulcer in a female patient with acute lymphoblastic leukaemia. A culture from the ecthyma lesion revealed the presence of Pesudomonas aeruginosa, but the results of repeated blood cultures were negative. The patient responded well to amikacin to which the isolate was susceptible in vitro. Considering high rate of mortality, early diagnosis and prompt effective treatment is mandatory.

Pleuropulmonary paragonimiasis mimicking pulmonary tuberculosis--a report of three cases.

Paragonimiasis is an important cause of pulmonary disease worldwide. Infection in humans mainly occurs by ingestion of raw or undercooked freshwater crabs or crayfish. The disease is well known in endemic regions of Asian countries, where culturally based methods of food preparation foster human transmission. Three patients with clinical and radiological features compatible with pulmonary tuberculosis had been treated for tuberculosis without remedy despite an inability to demonstrate acid fast bacilli in sputum smears. All patients had history of ingestion of raw crabs and crayfish. The confirmed diagnosis of pleuropulmonary paragonimiasis was made based on the demonstration of Paragonimus eggs in the sputum, and high absolute eosinophilia in their peripheral blood and pleural fluid. All the patients had been treated with praziquantel successfully.

Insecticidal action of the polyphenolic rich fractions from the stem bark of Streblus asper on Dysdercus cingulatus.

Extracts from the stem bark of Streblus asper possess insecticidal activity against the fifth instar of Dysdercus cingulatus. Methanolic extract showed an LC(50) value of 5.56 microg/insect. Partition with chloroform increased the insecticidal activity (LC(50) 2.01 microg/insect). Three polyphenolic rich fractions were obtained from silica-gel column chromatography of the chloroform fraction and found to have noteworthy insecticidal activity (LC(50): 1.82 microg, 2.70 microg, 2.26 microg/insect) by topical application. This may provide a useful beginning for the development of biopesticides.