Iron Oxide-Copper Mineral Associations in Supergene Zones: Insights into Flotation Challenges and Optimization Using Response Surface Methodology.

In this study, batch flotation tests were conducted to investigate the flotation of oxidized copper ore from the supergene zone of the Bounhas deposit. Utilizing the Response Surface Methodology (RSM) anchored on the Box-Behnken Design (BBD), the effects of parameters such as collector dosage, sulfidizing agent, copper oxide and iron oxide grades, and particle size on copper recovery were explored. ANOVA and response surface plots elucidated the complex behavior of copper flotation. Mineralogical analyses of the initial feed and postflotation tails were performed on an industrial scale using advanced Zeiss microscopy. The quadratic model with an R 2 of 94.49% accurately captured the impact of the process parameters on copper recovery. Among the key findings, the sulfidizing agent exhibited the most substantial quadratic effect, while the copper oxide grade had the most substantial linear impact on recovery. A pivotal observation was the link between copper losses in tailings and specific iron oxide-copper associations. Optimization identified conditions leading to a maximum copper recovery rate of 71.49%. When validated industrially, the model demonstrated robust applicability for analogous mineral processing contexts. The study's mineralogical insights enhance our understanding of the supergene zone mineralization and offer a solid foundation for subsequent in-depth mineral processing studies.

Rosenbergiella meliponini D21B Isolated from Pollen Pots of the Australian Stingless Bee Tetragonula carbonaria.

Rosenbergiella bacteria have been previously isolated predominantly from floral nectar and identified in metagenomic screenings as associated with bees. Here, we isolated three Rosenbergiella strains from the robust Australian stingless bee Tetragonula carbonaria sharing over 99.4% sequence similarity with Rosenbergiella strains isolated from floral nectar. The three Rosenbergiella strains (D21B, D08K, D15G) from T. carbonaria exhibited near-identical 16S rDNA. The genome of strain D21B was sequenced; its draft genome contains 3,294,717 bp, with a GC content of 47.38%. Genome annotation revealed 3236 protein-coding genes. The genome of D21B differs sufficiently from the closest related strain, Rosenbergiella epipactidis 2.1A, to constitute a new species. In contrast to R. epipactidis 2.1A, strain D21B produces the volatile 2-phenylethanol. The D21B genome contains a polyketide/non-ribosomal peptide gene cluster not present in any other Rosenbergiella draft genomes. Moreover, the Rosenbergiella strains isolated from T. carbonaria grew in a minimal medium without thiamine, but R. epipactidis 2.1A was thiamine-dependent. Strain D21B was named R. meliponini D21B, reflecting its origin from stingless bees. Rosenbergiella strains may contribute to the fitness of T. carbonaria.

A comprehensive review of COVID-19 detection techniques: From laboratory systems to wearable devices.

Screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among symptomatic and asymptomatic patients offers unique opportunities for curtailing the transmission of novel coronavirus disease 2019, commonly known as COVID-19. Molecular diagnostic techniques, namely reverse transcription loop-mediated isothermal amplification (RT-LAMP), reverse transcription-polymerase chain reaction (RT-PCR), and immunoassays, have been frequently used to identify COVID-19 infection. Although these techniques are robust and accurate, mass testing of potentially infected individuals has shown difficulty due to the resources, manpower, and costs it entails. Moreover, as these techniques are typically used to test symptomatic patients, healthcare systems have failed to screen asymptomatic patients, whereas the spread of COVID-19 by these asymptomatic individuals has turned into a crucial problem. Besides, respiratory infections or cardiovascular conditions generally demonstrate changes in physiological parameters, namely body temperature, blood pressure, and breathing rate, which signifies the onset of diseases. Such vitals monitoring systems have shown promising results employing artificial intelligence (AI). Therefore, the potential use of wearable devices for monitoring asymptomatic COVID-19 individuals has recently been explored. This work summarizes the efforts that have been made in the domains from laboratory-based testing to asymptomatic patient monitoring via wearable systems.

Isophthalate:coenzyme A ligase initiates anaerobic degradation of xenobiotic isophthalate.

BACKGROUND: Environmental contamination from synthetic plastics and their additives is a widespread problem. Phthalate esters are a class of refractory synthetic organic compounds which are widely used in plastics, coatings, and for several industrial applications such as packaging, pharmaceuticals, and/or paints. They are released into the environment during production, use and disposal, and some of them are potential mutagens and carcinogens. Isophthalate (1,3-benzenedicarboxylic acid) is a synthetic chemical that is globally produced at a million-ton scale for industrial applications and is considered a priority pollutant. Here we describe the biochemical characterization of an enzyme involved in anaerobic degradation of isophthalate by the syntrophically fermenting bacterium Syntrophorhabdus aromaticivorans strain UI that activate isophthalate to isophthalyl-CoA followed by its decarboxylation to benzoyl-CoA. RESULTS: Isophthalate:Coenzyme A ligase (IPCL, AMP-forming) that activates isophthalate to isophthalyl-CoA was heterologously expressed in E. coli (49.6 kDa) for biochemical characterization. IPCL is homologous to phenylacetate-CoA ligase that belongs to the family of ligases that form carbon-sulfur bonds. In the presence of coenzyme A, Mg2+ and ATP, IPCL converts isophthalate to isophthalyl-CoA, AMP and pyrophosphate (PPi). The enzyme was specifically induced after anaerobic growth of S. aromaticivorans in a medium containing isophthalate as the sole carbon source. Therefore, IPCL exhibited high substrate specificity and affinity towards isophthalate. Only substrates that are structurally related to isophthalate, such as glutarate and 3-hydroxybenzoate, could be partially converted to the respective coenzyme A esters. Notably, no activity could be measured with substrates such as phthalate, terephthalate and benzoate. Acetyl-CoA or succinyl-CoA did not serve as CoA donors. The enzyme has a theoretical pI of 6.8 and exhibited optimal activity between pH 7.0 to 7.5. The optimal temperature was between 25 °C and 37 °C. Denaturation temperature (Tm) of IPCL was found to be at about 63 °C. The apparent KM values for isophthalate, CoA, and ATP were 409 µM, 642 µM, and 3580 µM, respectively. Although S. aromaticivorans is a strictly anaerobic bacterium, the enzyme was found to be oxygen-insensitive and catalysed isophthalyl-CoA formation under both anoxic and oxic conditions. CONCLUSION: We have successfully cloned the ipcl gene, expressed and characterized the corresponding IPCL enzyme, which plays a key role in isophthalate activation that initiates its activation and further degradation by S. aromaticivorans. Its biochemical characterization represents an important step in the elucidation of the complete degradation pathway of isophthalate.

PCovNet: A presymptomatic COVID-19 detection framework using deep learning model using wearables data.

While the advanced diagnostic tools and healthcare management protocols have been struggling to contain the COVID-19 pandemic, the spread of the contagious viral pathogen before the symptom onset acted as the Achilles' heel. Although reverse transcription-polymerase chain reaction (RT-PCR) has been widely used for COVID-19 diagnosis, they are hardly administered before any visible symptom, which provokes rapid transmission. This study proposes PCovNet, a Long Short-term Memory Variational Autoencoder (LSTM-VAE)-based anomaly detection framework, to detect COVID-19 infection in the presymptomatic stage from the Resting Heart Rate (RHR) derived from the wearable devices, i.e., smartwatch or fitness tracker. The framework was trained and evaluated in two configurations on a publicly available wearable device dataset consisting of 25 COVID-positive individuals in the span of four months including their COVID-19 infection phase. The first configuration of the framework detected RHR abnormality with average Precision, Recall, and F-beta scores of 0.946, 0.234, and 0.918, respectively. However, the second configuration detected aberrant RHR in 100% of the subjects (25 out of 25) during the infectious period. Moreover, 80% of the subjects (20 out of 25) were detected during the presymptomatic stage. These findings prove the feasibility of using wearable devices with such a deep learning framework as a secondary diagnosis tool to circumvent the presymptomatic COVID-19 detection problem.

Hepatoprotective activity of melittin on isoniazid- and rifampicin-induced liver injuries in male albino rats.

BACKGROUND: The present study investigated the ameliorative effect of melittin, a major polypeptide in the venom of honeybee (Apis mellifera), on isoniazid-(INH) and rifampicin-(RIF) induced hepatotoxicity in male albino rats. METHOD: Thirty rats (140-200 g) were divided into five groups (n = 6): normal control (NC) received normal saline orally (NaCl, 0.9%; toxic (T) group received INH + RIF (each rat received 100 mg/kg, p.o.); melittin (Mel15, Mel30) groups (each rat received 15 or 30 µg/kg s.c); and normal recovery (NR) group received INH + RIF (each rat received 100 mg/kg, p.o.). Blood and liver samples were collected for biochemical, hematological and histopathological studies respectively. RESULTS: The administration of melittin was found to prevent the antitubercular drug-induced alterations in the diagnostic markers; reduced glutathione (GSH), direct bilirubin (DB), total bilirubin (TB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and total serum protein (TSP). Besides, hematological alterations were significantly high in Mel groups when compared to the toxic group. The NR group exhibited lower levels of DB, TB, ALP, LDH and TSP. In addition, treatment with melittin offered protection in the NR group with respect to MDA levels. CONCLUSION: Evidence from this study suggests that melittin is beneficial for the prevention of acute hepatic failure in antitubercular drug-induced hepatoxicity and could be used as a potential therapeutic agent.

Ferric-bipyridine assay: A novel spectrophotometric method for measurement of antioxidant capacity.

Measurement of the antioxidant potential using in vitro assays is paramount in the assessment of various food products and nutraceuticals. Researchers always attempt to develop more accurate assays which can be performed in unsophisticated conditions. This novel method, Ferric-Bipyridine reducing capacity of total antioxidants (FBRC) is a very simple, accurate assay performed based on the reduction of Fe (III) to Fe (II) by antioxidants with the formation of a colored complex with bipyridine (Bp) i.e, Fe(II)-Bp. The FBRC method thus developed was assessed under carefully adjusted parameters of oxidant concentration, pH, temperature, solvent, light and time in order to fix the optimum conditions for the assay. The spectrophotometric monitoring of Fe(II)-Bp complex was noted by the formation of an intense pink color at room temperature with absorption maxima at 535 nm, pH 4. The analytical performance of this method was fully validated, and the obtained results were satisfactory. It was successfully applied to measure the total antioxidant capacity of standard compounds such as gallic acid, ascorbic acid and butylated hydroxy toluene (BHT), in addition to some plant extracts and oils. The FBRC method is inexpensive, reproducible and simple to perform. In addition, the antioxidant activity of the tested compounds compared to common reference methods showed that the novel FBRC method is superior to the Ferric reducing antioxidant power (FRAP) with regard to its use of realistic pH and faster kinetics. Thus, the FBRC method is convenient for the estimation of total antioxidant in plants extracts, natural products, essential oils and food stuff.

Antioxidant and antihyperlipidemic activity of Costus speciosus against atherogenic diet-induced hyperlipidemia in rabbits.

OBJECTIVE: An extract of Costus speciosus (CSE), a herb widely used in folk medicine, was evaluated for its antioxidant, antihyperlipidemic and ameliorating effects on histopathological changes in atherogenic rabbits. METHODS: Twenty-four male rabbits (Oryctolagus cuniculus) were divided into 4 groups. Three groups were fed a diet containing 3% saturated fat and 1.3% cholesterol for 40 d. One of these was sacrificed on the 40th day and was called the pathogenic (P) group; the other two groups received treatment for another 30 d as follows: one received 0.8 g/(kg·d) of CSE and the other was given 0.01 g/(kg·d) of simvastatin. The normal group was sacrificed on the 70th day and used as a control. RESULTS: CSE showed radical-scavenging ability. Administration of CSE for a 30-day period resulted in a significant decrease in total cholesterol, triacylglycerol, low-density lipoprotein and aspartate aminotransferase compared to the P group, while levels of hemoglobin, packed corpuscular volume and red blood cells were elevated. With respect to studies performed on the heart, a decrease in malondialdehyde and an increase in reduced glutathione were noted. Total protein increased in the liver, heart and aorta after treatment with CSE and also a marked improvement in histopathological parameters was demonstrated. CONCLUSION: The present findings indicate that the C. speciosus rhizome possesses antiatherogenic and antioxidant properties which may provide protective effects against oxidative stress in atherosclerotic rabbits.

Hepatoprotective and antioxidant effects of single clove garlic against CCl4-induced hepatic damage in rabbits.

BACKGROUND: The increase in demand and consumption of single clove garlic or 'Solo garlic' (Allium sativum) has resulted in an increase in research on its therapeutic properties. The present study aims to evaluate the antioxidant activities, oxidant-scavenging efficiency and preventive effects of SCG (single clove garlic) and MCG (multi clove garlic) on CCl4-induced acute hepatotoxicity in male rabbits. METHODS: For this purpose, rabbits were orally administered with 3 ml of CCl4 /kg of body weight, followed by 0.8 g of MCG or SCG/kg twice a week for three successive weeks. Oxidative hepatotoxicity was then assessed. RESULTS: SCG extracts exhibited higher antioxidant capacity than the MCG extract. Scavenging ability of SCG showed significant (p < 0.05) elevation against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals in comparison to MCG. In addition, total phenolic content of SCG was significantly elevated (p < 0.001), thereby suggesting that the composition of garlic storage constituents varies with the number of cloves present. CCl4-induced hepatotoxicity demonstrated histological changes including severe damage in the structure of liver tissues which correlated well to oxidative stress levels. Simultaneously, administration of SCG resulted in a significant reduction of serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TB) levels in addition to improvement in some histological parameters. Low levels of lipid peroxidation (malondialdehyde, MDA) (p < 0.001), along with a huge reduction in peroxidase (POx) (p < 0.001) revealed protection against oxidative toxicity in the liver homogenate. Higher levels of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.05) when compared to the MCG test (TM) group indicates that removal of H2O2 is based on CAT activity in SCG test (TS) group rather than the POx activity demonstrated in the former group. CONCLUSION: The present study indicates that SCG possesses more protective ability than MCG against CCl4-induced liver injury and might be an effective alternative medicine against acute oxidative liver toxicity.

Evaluating the biodeterioration enzymatic activities of fungal contamination isolated from some ancient yemeni mummies preserved in the national museum.

Sophisticated mummification using chemical preservation was prevalent in ancient Yemeni civilization as noted in the 4th century B.C. mummies of the National Museum of Yemen, Sana'a, used in this study. Five of these mummies were used to evaluate hydrolytic enzymes produced as a result of fungal contamination. Forty-seven fungal species were isolated, thereby reflecting a high degree of contamination which may have resulted from the poor ventilation and preservation system. Aspergillus was the most common genus isolated (48.9%). Fifteen isolates exhibited ability to produce cellulase (EC; 3.2.1.4), Aspergillus candidus being the highest cellulose-producer. Pectin lyase (PL, EC; 4.2.2.2) and pectin methyl esterase (PME, EC; 3.1.1.11) were produced by Trichoderma hamatum, whereas chitinase (EC; 3.2.1.14) was produced by Aspergillus niger. Protease activity was noted by only Cladosporium herbarum. The higher activities of these fungal hydrolytic enzymes represent the major threats of biodeterioration including deteriorating linen bandages as well as the mummy bodies. Therefore, it is recommended to improve the preservation system of the mummies at the National Museum to minimize the contamination up to the lowest level and protect the mummies from biodeterioration.