Preparation of films based on reticulated fish gelatin containing garlic essential oil.

Agro-industrial co-products, such as fish gelatin, stand out for their capacity in forming biopolymeric films, being biocompatible and non-toxic; however, its hydrophilicity poses a challenge. Essential oils, rich in bioactives, attract research interest aiming to enhance the protective barrier of films and enable their application in packaging. This study produced films based on cross-linked Nile tilapia skin gelatin, incorporating garlic essential oil. Gelatin obtained through partial collagen hydrolysis from the fish skin and cross-linked with gallic acid had hydroxyproline content of 10.02 g 100 g-1 and gel strength of 287 g, which were consistent with other studies. Oil extraction used supercritical CO2 as a solvent and ethanol as a cosolvent, following a factorial experimental design, evaluating the extraction temperature (40 °C and 70 °C) and cosolvent ratio (1:1 and 1:3), with three central points. Extraction was successful, with higher yields on a dry basis at 70 °C (88.35 %), using a 1:1 cosolvent ratio. Films incorporated with oil exhibited lower water vapor permeability (WVP) than those with only cross-linked gelatin (1.59 (g m-1 s-1 Pa-1) 1011). The film with the most suitable tensile strength (19.07 MPa), elongation (120.91 %), and WVP (1.09 (g m-1 s-1 Pa-1) 1011) properties contained garlic oil extracted at the central point (55 °C and 1:2). Thermal analysis indicated increased melting temperatures in films with added oil, suggesting low thermal degradation. These results suggest that garlic oil addition can improve the properties of fish gelatin-based films, making them promising for biodegradable packaging.

Central composite design-assisted visual and non-invasive detection of sertraline by sweet lemon waste-derived core-shell AuNPs@CDs.

This study reports a fast and visual detection method of antidepressant sertraline (SRT) drug by the core-shell AuNPs@CDs as the nanoprobes. The CDs has been eco-friendly synthesized from sweet lemon wastes to directly reduce Au+ to AuNPs without any external photoirradiation process or additional reductants. Optimizing key variables that impact the sensing process has been done using the central composite design (CCD) approach to simulate the assay condition before the analysis. Adding SRT with different concentrations to the nanoprobes under mildly acidic conditions presents an absorbance peak at 560 nm with purple color tonalities that differ from the behavior of alone nanoprobes (530 nm, pink color). The obtained absorption change is linearly proportional to the increase of SRT concentration from 1 µM to 35 µM with a limit of detection (LOD) value of 100 nM. The color changes with a vivid tonality from pink and purple to violet as the colorful fingerprint patterns are readily traceable by the naked eye, allowing the visual assay of SRT. The greenness of the developed approach is well evaluated by some international indexes including the complimentary green analytical procedure (ComplexGAPI) and also, the analytical greenness (AGREE) indexes. The proposed waste-derived nanoprobes based on the eco-friendly procedure not only conduct quantitative and qualitative non-invasive analysis of SRT by the naked eye but also, may widen for other applications in various fields.

CdS/Bi2S3/NiS ternary heterostructure-based photoelectrochemical immunosensor for the sensitive detection of carbohydrate antigen 125.

The sensitive, accurate and rapid detection of carbohydrate antigen 125 (CA125) is essential for the early diagnosis and clinical management of ovarian cancer, but there is still challenge. Herein, a photoelectrochemical (PEC) immunosensor based on CdS/Bi2S3/NiS ternary sulfide heterostructured photocatalyst was presented for the detection of CA125. The CdS/Bi2S3/NiS was synthesized by a one-step hydrothermal approach. The heterojunction comprising of CdS and Bi2S3 could separate photogenerated carriers, the introduced narrow bandgap NiS could act as electron-conducting bridge to facilitate the transfer of interfacial photogenerated electrons, thereby improving the photoelectric conversion efficiency. Due to their synergistic effect, the photocurrent response produced by the composite was up to 14.6 times of pure CdS. On the basis, a PEC immunosensor was constructed by introducing the CA125 antibody through thioglycolic acid linkage. It was found that the resulting immunosensor showed good performance. Under the optimized conditions, its linear detection range was as wide as 1 pg mL-1-50 ng mL-1, and the detection limit was low to 0.85 pg mL-1. Furthermore, we experimentally tested its anti-interference, stability and reproducibility, and satisfactory results were achieved. The practicable feasibility of the sensor was confirmed by testing serum sample. Thus this work provided a simple, fast and enough sensitive approach for CA125 monitoring.

Photoelectrochemical immunoassay of cardiac troponin I based on ZnTCPP/CdIn2S4 type-II heterojunction and co-catalyzed precipitation biolabeling.

CdIn2S4 and zinc tetrakis(4-carboxyphenyl)porphyrin (ZnTCPP) were synthesized by hydrothermal method, and an organic dye-sensitized inorganic semiconductor ZnTCPP/CdIn2S4 type II heterojunction was constructed on a fluorine-doped tin oxide (FTO) substrate electrode. A sandwich immunostructure for signal-attenuation photoelectrochemical (PEC) detection of cardiac troponin I (cTnI) was constructed using the ZnTCPP/CdIn2S4/FTO photoanode and a horseradish peroxidase (HRP)-ZnFe2O4-Ab2-bovine serum albumin (BSA) immunolabeling complex. The bioenzyme HRP and the HRP-like nanozyme ZnFe2O4 can co-catalyze the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to produce an insoluble precipitate on the photoanode, thus notably reducing the anodic photocurrent for quantitative determination of cTnI. Under the optimal conditions, the photocurrent at 0 V vs. SCE in 0.1 M phosphate buffer solution (pH 7.40) containing 0.1 M ascorbic acid was linear with the logarithm of cTnI concentration from 500 fg mL-1 to 50.0 ng mL-1, and the limit of detection (LOD, S/N = 3) is 0.15 pg mL-1. Spiked recoveries were 95.1% ~ 104% for assay of cTnI in human serum samples.

Dual-mode photoelectrochemical radar based on CdS quantum dot and Ce-MOF for detection of low-abundance disease-associated proteins.

Herein, we developed a convenient and versatile dual-mode electrochemiluminescence (ECL) and photoelectrochemistry (PEC) sensing radar for the detection of Prostate-specific antigen (PSA), which has important implications for detection of low-abundance disease-associated proteins. Cerium-based metal-organic framework (Ce-MOFs) were firstly modified on the electrode, showing well ECL and PEC property. In particular, a unique multifunctional Au@CdS quantum dots (QDs) probe loaded numerous QDs and antibody was fabricated, not only displaying strong ECL and PEC signals, but also having specific recognition to PSA. After the signal probe was linked to the electrode by immune reaction, much amplified signals of ECL and PEC were generated for double-mode detection of PSA. Therefore, this work proposed a multifunctional Au@CdS QDs signal probe with excellent ECL and PEC performance, and developed an ultrasensitive photoelectric biosensing platform for dual-mode detection, which provides an effective method for health monitoring of cancer patients.

A highly sensitive point-of-care detection platform for Salmonella typhimurium by integrating magnetic enrichment and fluorescent CsPbBr3@SiO2.

A platform was designed based on Fe3O4 and CsPbBr3@SiO2 for integrated magnetic enrichment-fluorescence detection of Salmonella typhimurium, which significantly simplifies the detection process and enhances the working efficiency. Fe3O4 served as a magnetic enrichment unit for the capture of S. typhimurium. CsPbBr3@SiO2 was employed as a fluorescence-sensing unit for quantitative signal output, where SiO2 was introduced to strengthen the stability of CsPbBr3, improve its biomodificability, and prevent lead leakage. More importantly, the SiO2 shell shows neglectable absorption or scattering towards fluorescence, making the CsPbBr3@SiO2 exhibit a high quantum yield of 74.4%. After magnetic enrichment, the decreasing rate of the fluorescence emission intensity of the CsPbBr3@SiO2 supernatant at 527 nm under excitation light at UV 365 nm showed a strong linear correlation with S. typhimurium concentration of 1 × 102~1 × 108 CFU∙mL-1, and the limit of detection (LOD) reached 12.72 CFU∙mL-1. This platform has demonstrated outstanding stability, reproducibility, and resistance to interference, which provides an alternative for convenient and quantitative detection of S. typhimurium.

Effect of pyrite particle size on the denitrification performance of autotrophic or split-mixotrophic bioreactors supported by pyrite/polycaprolactone.

In this study, a pyrite-based autotrophic denitrification (PAD) system, a polycaprolactone (PCL)-supported heterotrophic denitrification (PHD) system, and a pyrite+PCL-based split-mixotrophic denitrification (PPMD) system were constructed. The pyrite particle size was controlled in 1-3, 3-5, or 5-8 mm in both the PAD and PPMD systems to investigate the effect of pyrite particle size on the denitrification performance of autotrophic or split-mixotrophic bioreactors. It was found that the PAD system achieved the best denitrification efficiency with an average removal rate of 98.98% in the treatment of 1- to 3-mm particle size, whereas it was only 19.24% in the treatment of 5- to 8-mm particle size. At different phases of the whole experiment, the nitrate removal rates of both the PHD and PPMD systems remained stable at a high level (>94%). Compared with the PAD or PHD system, the PPMD system reduced the concentrations of sulfate and chemical oxygen demand in the final effluent efficiently. The interconnection network diagram explained the intrinsic metabolic pathways of nitrogen, sulfur, and carbon in the three denitrification systems at different phases. In addition, the microbial community analysis showed that the PPMD system was beneficial for the enrichment of Firmicutes. Finally, the impact mechanism of pyrite particle size on the performance of the PPMD system was proposed. PRACTITIONER POINTS: The reduction of pyrite particle size was beneficial for improving the efficiency of the PAD process. The change in particle size had an effect on NO2 --N accumulation in the PAD system. The accumulation of NH4 +-N in the PPMD system increased with the decrease in particle size. The reduction of pyrite particle size increased the production of SO4 2- in the PAD and PPMD systems. The correlations among the effluent indicators of the PAD and PPMD systems could be well explained.

Biosynthesis of photostable CdS quantum dots by UV-resistant psychrotolerant bacteria isolated from Union Glacier, Antarctica.

BACKGROUND: Quantum Dots (QDs) are fluorescent nanoparticles with exceptional optical and optoelectronic properties, finding widespread utility in diverse industrial applications. Presently, chemically synthesized QDs are employed in solar cells, bioimaging, and various technological domains. However, many applications demand QDs with prolonged lifespans under conditions of high-energy radiation. Over the past decade, microbial biosynthesis of nanomaterials has emerged as a sustainable and cost-effective process. In this context, the utilization of extremophile microorganisms for synthesizing QDs with unique properties has recently been reported. RESULTS: In this study, UV-resistant bacteria were isolated from one of the most extreme environments in Antarctica, Union Glacier at the Ellsworth Mountains. Bacterial isolates, identified through 16 S sequencing, belong to the genera Rhodococcus, Pseudarthrobacter, and Arthrobacter. Notably, Rhodococcus sp. (EXRC-4 A-4), Pseudarthrobacter sp. (RC-2-3), and Arthrobacter sp. (EH-1B-1) tolerate UV-C radiation doses ≥ 120 J/m². Isolated UV-resistant bacteria biosynthesized CdS QDs with fluorescence intensities 4 to 8 times higher than those biosynthesized by E. coli, a mesophilic organism tolerating low doses of UV radiation. Transmission electron microscopy (TEM) analysis determined QD sizes ranging from 6 to 23 nm, and Fourier-transform infrared (FTIR) analysis demonstrated the presence of biomolecules. QDs produced by UV-resistant Antarctic bacteria exhibit high photostability after exposure to UV-B radiation, particularly in comparison to those biosynthesized by E. coli. Interestingly, red fluorescence-emitting QDs biosynthesized by Rhodococcus sp. (EXRC-4 A-4) and Arthrobacter sp. (EH-1B-1) increased their fluorescence emission after irradiation. Analysis of methylene blue degradation after exposure to irradiated QDs biosynthesized by UV-resistant bacteria, indicates that the QDs transfer their electrons to O2 for the formation of reactive oxygen species (ROS) at different levels. CONCLUSIONS: UV-resistant Antarctic bacteria represent a novel alternative for the sustainable generation of nanostructures with increased radiation tolerance-two characteristics favoring their potential application in technologies requiring continuous exposure to high-energy radiation.

Shaping the Future of the Neurotransmitter Sensor: Tailored CdS Nanostructures for State-of-the-Art Self-Powered Photoelectrochemical Devices.

Semiconductor-based photoelectrochemical (PEC) test protocols offer a viable solution for developing efficient individual health monitoring by converting light and chemical energy into electrical signals. However, slow reaction kinetics and electron-hole complexation at the interface limit their practical application. Here, we reported a triple-engineered CdS nanohierarchical structures (CdS NHs) modification scheme including morphology, defective states, and heterogeneous structure to achieve precise monitoring of the neurotransmitter dopamine (DA) in plasma and noninvasive body fluids. By precisely manipulating the Cd-S precursor, we achieved precise control over ternary CdS NHs and obtained well-defined layered self-assembled CdS NHs through a surface carbon treatment. The integration of defect states and the thin carbon layer effectively established carrier directional transfer pathways, thereby enhancing interface reaction sites and improving the conversion efficiency. The CdS NHs microelectrode fabricated demonstrated a remarkable negative response toward DA, thereby enabling the development of a miniature self-powered PEC device for precise quantification in human saliva. Additionally, the utilization of density functional theory calculations elucidated the structural characteristics of DA and the defect state of CdS, thus establishing crucial theoretical groundwork for optimizing the polymerization process of DA. The present study offers a potential engineering approach for developing high energy conversion efficiency PEC semiconductors as well as proposing a novel concept for designing sensitive testing strategies.

Improving the anti-diabetic and anti-hyperlipidemic activities of extra virgin olive oil by the incorporation of diallyl sulfide.

Development of novel functional foods is trending as one of the hot topics in food science and food/beverage industries. In the present study, the anti-diabetic, anti-hyperlipidemic and histo-protective effects of the extra virgin olive oil (EVOO) enriched with the organosulfur diallyl sulfide (DAS) (DAS-rich EVOO) were evaluated in alloxan-induced diabetic mice. The ingestion of EVOO (500µL daily for two weeks) attenuated alloxan-induced elevated glucose, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, lactate dehydrogenase (LDH), urea and creatinine. It also normalized the levels of triglycerides (TG), total cholesterols (TC), low-density lipoprotein-cholesterol (LDL-c) and their consequent atherogenic index of plasma (AIP) in diabetic animals. Additionally, EVOO prevented lipid peroxidation (MDA) and reduced the level of hydrogen peroxide (H2O2) in diabetic animals. Concomitantly, it enhanced the activity of the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), reducing thereby tissue oxidative stress injury. The overall histologic (pancreas, liver, and kidney) alterations were also improved after EVOO ingestion. The manifest anti-diabetic, lipid-lowering and histo-protective properties of EVOO were markedly potentiated with DAS-rich EVOO suggesting possible synergistic interactions between DAS and EVOO lipophilic bioactive ingredients. Overall, EVOO and DAS-rich EVOO show promise as functional foods and/or adjuvants for the treatment of diabetes and its complications.

Ultrasensitive detection of chlortetracycline in animal-origin food using molecularly imprinted electrochemical sensor based on SnS2/ZnCo-MOF and AuNPs.

The chlortetracycline (CTC) residue in food poses a threat to human health. Therefore, developing sensitive, convenient and selective analytical methods for CTC detection is crucial. This study innovatively uses tin disulfide/bimetallic organic framework (SnS2/ZnCo-MOF) nanocomposites in conjunction with gold nanoparticles (AuNPs) to co-modify a glassy carbon electrode (GCE). Further, a molecularly imprinted polymer (MIP)-based electrochemical sensing platform Au-MIP/SnS2/ZnCo-MOF/Au/GCE (AZG) was fabricated for selective CTC detection. SnS2/ZnCo-MOF enhanced the stability and surface area of the AZG sensor. The presence of AuNPs facilitated electron transport between the probe and the electrode across the insulating MIP layer. The fixation of AuNPs and MIP via electropolymerization enhanced the selective recognition of this sensor and amplified its output signal. The AZG sensor demonstrated a wide linear detection range (0.1-100 µM), low detection limit (0.072 nM), and high sensitivity (0.830 µA µM-1). It has been used for detecting CTC in animal-origin food with good recovery (96.08%-104.60%).

Ultrasonic-induced grafted lanthanum sulfide decorated multi-walled carbon nanotube onto bacterial cellulose applied for adsorption of pesticides in environmental waters.

A new biosorbent was fabricated by modification of bacterial cellulose biopolymer grafted with lanthanum sulfide decorated carboxylated multiwall carbon nanotube (La2S3@MWCNT@BC). The sorbent was employed in a green alternative dispersive-solid phase extraction of a variety of 14 pesticides in environmental water samples. The analyses were performed using GC-µECD. The properties and structure of La2S3@MWCNT@BC nanocomposite were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and adsorption-desorption isotherms. The composition of the sorbent was also investigated to evaluate the adsorptive properties of its constituents. The impact of various parameters influencing extraction efficacies such as sorbent dose, adsorption time, sample pH, ionic strength, and desorption conditions was investigated. The method was validated by specificity, matrix effect % (-0.4 to -7.4), enrichment factor (4-10), limits of quantification (0.007-0.31 µg L-1), matrix-matched calibration linearity (0.01-200 µg L-1), determination coefficients (r2=0.9921-0.9998), and precision. The optimized method was applied for the analysis of multiclass pesticides in seven environmental and drinking waters and the recoveries were obtained in the 81-108 % range with RSDs of 2.5-4.7 %. This paper is the first report on the synthesis and use of La2S3@MWCNT@BC nanocomposite to extract pesticides from different water samples. The greenness of the procedure was evaluated by the AGREE protocols.

A label-free photoelectrochemical biosensor for silver ions based on Zn-Co doped C and CdS QD nanomaterials.

A sensitive photoelectrochemical (PEC) biosensor for silver ions (Ag+) was developed based on Zn-Co doped C and CdS quantum dot (CdS QD) nanomaterials. Hydrophobic modified sodium alginate (HMA), which could stabilize and improve the PEC performance of CdS QDs, was also used for the construction of PEC sensors. Especially, Zn-Co doped C, CdS QDs and HMA were sequentially modified onto an electrode surface via the drop-coating method, and a C base rich DNA strand was then immobilized onto the modified electrode. As the C base in DNA specifically recognized Ag+, it formed a C-Ag+-C complex in the presence of Ag+, which created a spatial steric hindrance, resulting in a reduced PEC response. The sensing platform is sensitive to Ag+ in the range of 10.0 fM to 0.10 µM, with a limit of detection of 3.99 fM. This work offers an ideal platform to determine trace heavy metal ions in environmental monitoring and bioanalysis.

Cr(VI) removal during cotransport of nano-iron-particles combined with iron sulfides in groundwater: Effects of D. vulgaris and S. putrefaciens.

Iron-based materials such as nanoscale zerovalent iron (nZVI) are effective candidates to in situ remediate hexachromium (Cr(VI))-contaminated groundwater. The anaerobic bacteria could influence the remediation efficiency of Cr(VI) during its cotransport with nZVI in porous media. To address this issue, the present study investigated the adsorption and reduction of Cr(VI) during its cotransport with green tea (GT) modified nZVI (nZVI@GT) and iron sulfides (FeS and FeS2) in the presence of D. vulgaris or S. putrefaciens in water-saturated sand columns. Experimental results showed that the nZVI@GT preferred to heteroaggregate with FeS2 rather than FeS, forming nZVI@GT-FeS2 heteroaggregates. Although the presence of D. vulgaris further induced nZVI@GT-FeS2 heteroaggregates to form larger clusters, it pronouncedly improved the dissolution of FeS and FeS2 for more Cr(VI) reduction associated with lower Cr(VI) flux through sand. In contrast, S. putrefaciens could promote the dispersion of the heteroaggregates of nZVI@GT-FeS2 and the homoaggregates of nZVI@GT or FeS by adsorption on the extracellular polymeric substances, leading to the improved transport of Fe-based materials for a much higher Cr(VI) immobilization in sand media. Overall, our study provides the essential perspectives into a chem-biological remediation technique through the synergistic removal of Cr(VI) by nZVI@GT and FeS in contaminated groundwater. ENVIRONMENTAL IMPLICATION: The green-synthesized nano-zero-valent iron particles (nZVI@GT) using plant extracts (or iron sulfides) have been used for in situ remediation of Cr(VI) contaminated groundwater. Nevertheless, the removal of Cr(VI) (including Cr(VI) adsorption and Cr(III) generation) could be influenced by the anaerobic bacteria governing the transport of engineered nanoparticles in groundwater. This study aims to reveal the inherent mechanisms of D. vulgaris and S. putrefaciens governing the cotransport of nZVI@GT combined with FeS (or FeS2) to further influence the Cr(VI) removal in simulated complex groundwater media. Our findings provides a chemical and biological synergistic remediation strategy for nZVI@GT application in Cr(VI)-contaminated groundwater.

Fluorescence based methodology with greenness consideration for concurrent estimation of anti-allergic medication; application to dosage form.

A green, sensitive and rapid spectrofluorimetric method for quantitative assay of an anti-allergic medication composed of montelukast and fexofenadine mixture in raw materials and dosage form was developed. The method was based on measuring the synchronous fluorimetric peak without interference, pre-separation or pre-extraction procedures. Montelukast was analyzed at 360 nm while fexofenadine was measured at 263 nm using Δλ = 20 nm for both drugs using ethanol as diluting solvent and acetate buffer of pH 4. The assay was rectilinear over the concentration range of 1.0-10.0 µg/mL for fexofenadine and 0.1-0.6 µg/mL for montelukast. The method was full validated according to ICH guidelines. The applicability of the method enables the assay of both drugs in raw materials, synthetic mixture as well as combined tablets. Moreover, the greenness of the method was assessed using different methods including; analytical eco-scale, GAPI and AGREE. All of these methods confirm that the proposed method is an eco-friendly method.

Copper recovery from waste printed circuit boards using pyrite as the bioleaching substrate.

Waste printed circuit boards (WPCBs) can be bioleached for Cu recovery, but lack of substrate for the bioleaching culture. In this study, using pyrite as a bacterial substrate for bioleaching WPCBs and recovering Cu was explored. The results showed that the WPCBs bioleaching using pyrite as the bacterial substrate was feasible. Mechanical crushing was a suitable WPCBs pretreatment method. The optimal WPCBs and pyrite pulp densities were respectively found to be 1.25% (w/v) and 1.0% (w/v), and the suitable nitrogen source ratio ((NH4)2SO4: (NH4)2HPO4) was deemed as 2 g/L: 2 g/L, achieving a Cu2+ leaching efficiency of 95.60 ± 1.57% in 14 d. Copper in the bioleaching solution can be directly recovery via electrodeposition. The Cu recovery efficiency in 60 min was up to 92.19 ± 1.35% under the optimal condition that the initial Cu2+ concentration and pH were respectively set at 7.34 g/L and 2.75, and the current density was set at 200 A/m2. Copper was found as the dominant metal in the cathode deposits, existing in the form of Cu and Cu2O. This work provided a novel approach for bioleaching WPCBs and recovering Cu.

MXene/ZnS/chitosan-cellulose composite with Schottky heterostructure for efficient removal of anionic dyes by synergistic effect of adsorption and photocatalytic degradation.

Nowadays, dye water pollution is becoming increasingly severe. Composite of MXene, ZnS, and chitosan-cellulose material (MX/ZnS/CC) was developed to remove anionic dyes through the synergistic effect of adsorption and photocatalytic degradation. MXene was introduced as the cocatalyst to form Schottky heterostructure with ZnS for improving the separation efficiency of photocarriers and photocatalytic performance. Chitosan-cellulose material mainly served as the dye adsorbent, while also could improve material stability and assist in generation of free radicals for dye degradation. The physics and chemistry properties of MX/ZnS/CC composite were systematically inspected through various characterizations. MX/ZnS/CC composite exhibited good adsorption ability to anionic dyes with adsorption capacity up to 1.29 g/g, and excellent synergistic effects of adsorption and photodegradation with synergistic removal capacity up to 5.63 g/g. MX/ZnS/CC composite performed higher synergistic removal ability and better optical and electrical properties than pure MXene, ZnS, chitosan-cellulose material, and MXene/ZnS. After compounding, the synergistic removal percentage of dyes increased by a maximum of 309 %. MX/ZnS/CC composite mainly adsorbs anionic dyes through electrostatic interactions and catalyzes the generation of •O2-, h+, and •OH to degrade dyes, which has been successfully used to remove anionic dyes from environmental water, achieving a 100 % removal of 50 mg/L dye.

Nitrate Chemodenitrification by Iron Sulfides to Ammonium under Mild Conditions and Transformation Mechanism.

Autotrophic denitrification utilizing iron sulfides as electron donors has been well studied, but the occurrence and mechanism of abiotic nitrate (NO3-) chemodenitrification by iron sulfides have not yet been thoroughly investigated. In this study, NO3- chemodenitrification by three types of iron sulfides (FeS, FeS2, and pyrrhotite) at pH 6.37 and ambient temperature of 30 °C was investigated. FeS chemically reduced NO3- to ammonium (NH4+), with a high reduction efficiency of 97.5% and NH4+ formation selectivity of 82.6%, but FeS2 and pyrrhotite did not reduce NO3- abiotically. Electrochemical Tafel characterization confirmed that the electron release rate from FeS was higher than that from FeS2 and pyrrhotite. Quenching experiments and density functional theory calculations further elucidated the heterogeneous chemodenitrification mechanism of NO3- by FeS. Fe(II) on the FeS surface was the primary site for NO3- reduction. FeS possessing sulfur vacancies can selectively adsorb oxygen atoms from NO3- and water molecules and promote water dissociation to form adsorbed hydrogen, thereby forming NH4+. Collectively, these findings suggest that the NO3- chemodenitrification by iron sulfides cannot be ignored, which has great implications for the nitrogen, sulfur, and iron cycles in soil and water ecosystems.

Effect of compaction on bisulfide diffusive transport through MX-80 bentonite.

Canada's deep geological repository (DGR) design includes an engineered barrier system where highly compacted bentonite (HCB) surrounds the copper-coated used fuel containers (UFCs). Microbial-influenced corrosion is a potential threat to long-term integrity of UFC as bisulfide (HS-) may be produced by microbial activities under anaerobic conditions and transported via diffusion through the HCB to reach the UFC surface, resulting in corrosion of copper. Therefore, understanding HS- transport mechanisms through HCB is critical for accurate prediction of copper corrosion allowance. This study investigated HS- transport behaviour through MX-80 bentonite at dry densities 1070-1615 kg m-3 by performing through-diffusion experiments. Following HS- diffusion, bromide (Br-) diffusion and Raman spectroscopy analyses were performed to explore possible physical or mineralogical alterations of bentonite caused by interacting with HS-. In addition, accessible porosity ε was estimated using extended Archie's law. Effective diffusion coefficient of HS- was found 2.5 × 10-12 m2 s-1 and 5.0× 10-12 m2 s-1 for dry densities 1330 and 1070 kg m-3, respectively. No HS- breakthrough was observed for highly compacted bentonite (1535-1615 kg m-3) over the experimental timeframe (170 days). Raman spectroscopy results revealed that HS- reacted with iron in bentonite and precipitated as mackinawite and, therefore, it was immobilized. Finally, results of this study imply that HS- transport towards UFC will be highly controlled by the available iron content and dry density of the buffer material.

Semisynthesis and biological evaluation of novel honokiol thioethers against colon cancer cells HCT116 via inhibiting the transcription and expression of YAP protein.

Honokiol, derived from Magnolia officinalis (a traditional Chinese medicine), has been reported to have anticancer activity. Here, a series of novel honokiol thioethers bearing a 1,3,4-oxadiazole moiety were prepared and evaluated for their anticancer activities against three types of digestive system tumor cells. Biological evaluation showed that honokiol derivative 3k exhibited the best antiproliferative activity against HCT116 cells with an IC50 value of 6.1 µmol/L, superior to the reference drug 5-fluorouracil (IC50: 9.63 ± 0.27 µmol/L). The structure-activity relationships (SARs) indicated that the introduction of -(4-NO2)Ph, 3-pyridyl, -(2-F)Ph, -(4-F)Ph, -(3-F)Ph, -(4-Cl)Ph, and -(3-Cl)Ph groups was favorable for enhancing the anticancer activity of the title honokiol thioethers. Further study revealed that honokiol thioether 3k can well inhibit the proliferation of colon cancer cells HCT116, arresting the cells in G1 phase and inducing cell death. Moreover, a preliminary mechanism study indicated that 3k directly inhibits the transcription and expression of YAP protein without activating the Hippo signaling pathway. Thus, honokiol thioether 3k could be deeply developed for the development of honokiol-based anticancer candidates.