Being one of the hazardous contaminants in the environment, continuous exposure to cadmium ions (Cd(II)) has been shown to severely affect the well being of both humans and animals. Therefore, development of a highly sensitive method to detect trace amounts of such substance in the environment acquires scientific pertinence. In this present work, carbon paste electrode modified with bis(benzylidene)ethelynediamine (BBE-CPE) was used for the determination of Cd(II) using square wave anodic stripping voltammetric (SWASV) technique. A response surface methodological approach employing the Box-Behnken design (BBD) based on four relevant variables viz. pH, deposition time, percentage ligand and deposition potential was used for optimizing the experimental conditions for detecting such ions. Under optimized conditions (supporting electrolyte: pH 4.5, deposition time: 350 s, ligand graphite composition: 6%, deposition potential: ‒1.1 V), a linear response over a wide range of Cd(II) concentrations (1–500 µg L−1) with low detection limit (0.4 µg L-1) and quantification limit (1.4 µg L-1) were observed with deposition time being the most impacting factor. Pertinently, the BBE-CPE developed here exhibited exceptional recovery of Cd(II) concentrations in the sea and tap water samples, comparable with that observed under simulated conditions, suggesting its applicability for a variety of real samples. © 2020 Trans Tech Publications Ltd, Switzerland.

Increasing energy demands call for sustainable alternative sources. Solid state fermentation (SSF) of raw oil palm frond leaves (OPFL) as the substrate to produce extracellular cellulases and xylanase by a novel Rhizopus oryzae UC2 (GenBank accession no. MF767597) was optimized. Optimum SSF conditions (30 °C, 40% moisture content, 2.0 × 108 spores/g inoculum size) yielded the maximum carboxymethyl cellulase (CMCase) (94.68 U/g), filter paperase (FPase) (25.46 U/g), β-glucosidase (145.47 U/g) and xylanase (213.99 U/g) activities, showing a broad pH range of between 6.0 and 12.0. Proteome analysis of crude enzyme cocktail revealed three β-glucosidases, as well as one endo-β-1,4-glucanase, exoglanase and endo-β-1,4-xylanase each. Activities of the enzyme complex were maximal at an acidic pH and temperature that ranged between pH 3.0–5.0 and 50–60 °C, respectively. In situ hydrolysis of OPFL released various concentrations of sugars viz. glucose (26.74 mg/g), xylose (1.44 mg/g), fructose (50.8 mg/g) and cellobiose (58.31 mg/g). Moreover, CMCase, FPase, β-glucosidase and xylanase exhibited half-lives of 5.13, 1.48, 18.81, 9.23 h when incubated at 60 °C, respectively. Thus, the desirable qualities of R. oryzae UC2 seen here supported its prospective biocatalytic role for timely and safe production of digestible carbohydrates from agro-industrial biomass for the subsequent biotransformation into biofuel. © 2019 Elsevier Ltd

The use of 21 autosomal STR loci for human identification has been gaining popularity throughout the world. It has been indicated that the forensic statistical parameters for supporting the use of 21 STR loci varied among different populations. Hitherto, such data for the diverse Malaysian populations remain unreported, rendering doubts in the court of law about its real ability for human identification in Malaysian population. Using the GlobalFiler™ Express PCR Amplification Kit, complete DNA profiles of 21 STR loci from buccal swabs of convicted Malaysian criminal (n = 570; 190 each for Malays, Chinese, and Indians) (by the year 2016–2017) were analyzed for their allele frequencies, exact test of Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, power of exclusion, match probability, and polymorphism information content. Most of the loci were found to be in the Hardy-Weinberg equilibrium after the Bonferroni correction. Being the most informative locus, SE33 demonstrated the highest power of discrimination and power of exclusion, indicating its usefulness to discriminate individuals. In contrast, TPOX had the lowest power of discrimination and power of exclusion, as well as being the less informative genetic locus for all Malaysian population studied here. The probabilities that two individuals would share the same DNA profiles among the Malaysian Malays, Chinese, and Indians, as well as in general Malaysian population, were 1.3713 × 10−25, 2.8822 × 10−25, 7.5668 × 10−26, and 1.0385 × 10−26, respectively. The results obtained here were found comparable with similar studies reported in other populations. Hence, its robustness for forensic human identification among the Malaysian populations is, therefore, statistically supported.

Evidences of crime are often disposed in waterways to destroy all ties to the crime. Nonetheless, these evidences are not inevitably lost as the water insoluble lipid components may remain on the object. Currently, Small Particle Reagent (SPR) is used for visualizing such wet fingerprints and it comprises of several chemicals that are relatively hazardous to the crime investigator and the environment. The adaptation of a greener nano-biotechnological route might be useful, but there is still much to be done to improve this fingerprint visualisation method. Henceforth, this study was carried out to optimise the visualization protocol for CRL-MWCNTs/GA/I3K/SAF on split natural fingerprints immersed in purified tap water for one-and 15 days using response surface methodology (RSM). The addition of I3K as the mordant expedited the overall staining process. This study achieved a better mean fingerprints quality for the one-day immersed samples fared better compared to 15 days, thus suggesting the adequate use of CRL in the formulation. Hence, it was shown that RSM is reliable in predicting the optimum condition that yielded the highest mean fingerprint quality for both time intervals (one and 15 days). © 2020, Institute of Chemistry, Slovak Academy of Sciences.

Ananas comosus (L.) Merr is one of many commercially popular fruits in the cannery food industry that contributes to the increasingly mounting agro-industrial waste. In this study, a four−factor−three−level Box−Behnken design (BBD) that comprised of sonication time (A), solvent ratio (B), amplitude (C) and liquid−solid ratio (D) for the ultrasound−assisted extraction (UAE) of pineapple peels (PP) was utilized to optimize the yield of total phenolic content (TPC). Under an optimized UAE condition [5 min; 50 % of ethanol: water; 65 % of amplitude; 35:1 mL/g of liquid−solid ratio], the highest TPC from PP of 708.10 mg gallic acid equivalent (GAE)/g DW was achieved. Antioxidant capacity analysis of PP revealed a high total flavonoid content (TFC) with the IC50 for 2,2−diphenyl−1−picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) of 1146.86 ± 11.83 mg QE/g, 11.83 mg/mL and 1578.07 ± 25.96 µM Fe (II)/100g, respectively. High-performance liquid chromatography (HPLC) analysis revealed that the major flavonoid in the phenolic profile of PP extracts being catechin followed by quercetin and gallic acid. The UAE of PP extracts exhibited higher TPC than known conventional extraction techniques, thus indicating its efficacy to recover satisfactory quantities of phenolics in PP under optimized conditions. © 2020 Penerbit UTM Press. All rights reserved.