Kinetic and Mechanistic Modelling of Pyrimethanil Fungicide Adsorption onto Soils of Varying Physico-chemical Properties.

Pesticide transport in the environment is impacted by the kinetics of its adsorption onto soil. The adsorption kinetics of pyrimethanil was investigated in ten soil samples of varying physicochemical properties. The highest adsorption was in the soil having the maximum silt and CaCO3 contents, pH and electrical conductance but the lowest amorphous Fe oxides and CaCl2 extractable Mn. Pseudo-second order kinetics and intra-particle diffusion model best accounted the adsorption kinetics of pyrimethanil. The equilibrium adsorption estimated by pseudo-second order kinetics (q02) was significantly and positively correlated with CaCl2 extractable Cu content (r = 0.709) while rate coefficient (k02) had a negative correlation with crystalline iron oxides content (r = -0.675). The intra-particle diffusion coefficient (ki.d.) had inverse relationship with CaCl2 extractable Mn content in soils (r = -0.689). FTIR spectra showed a significant interaction of pyrimethanil with micronutrient cations. Adsorption kinetic parameters of pyrimethanil could be successfully predicted by soil properties. The findings may help to evolve fungicide management decisions.

Distribution Clearance: Significance and Underlying Mechanisms.

PURPOSE: Evaluation of distribution kinetics is a neglected aspect of pharmacokinetics. This study examines the utility of the model-independent parameter whole body distribution clearance (CLD) in this respect. METHODS: Since mammillary compartmental models are widely used, CLD was calculated in terms of parameters of this model for 15 drugs. The underlying distribution processes were explored by assessment of relationships to pharmacokinetic parameters and covariates. RESULTS: The model-independence of the definition of the parameter CLD allowed a comparison of distributional properties of different drugs and provided physiological insight. Significant changes in CLD were observed as a result of drug-drug interactions, transporter polymorphisms and a diseased state. CONCLUSION: Total distribution clearance CLD is a useful parameter to evaluate distribution kinetics of drugs. Its estimation as an adjunct to the model-independent parameters clearance and steady-state volume of distribution is advocated.

Pharmacokinetics and Histotoxic Profile of a Novel Azithromycin-Loaded Lipid-Based Nanoformulation.

Azithromycin traditional formulations possesses poor oral bioavailability which necessitates development of new formulation with enhanced bioavailability of the drug. The objective of current research was to explore the kinetics and safety profile of the newly developed azithromycin lipid-based nanoformulation (AZM-NF). In the in-vitro study of kinetics profiling, azithromycin (AZM) release was assessed using dialysis membrane enclosing equal quantity of either AZM-NF, oral suspension of azithromycin commercial product (AZM-CP), or azithromycin pure drug (AZM-PD) in simulated intestinal fluid. The ex-vivo study was performed using rabbit intestinal segments in physiological salts solution in a tissue bath. The in-vivo study was investigated by oral administration of AZM to rabbits while taking blood samples at predetermined time-intervals, followed by HPLC analysis. The toxicity study was conducted in rats to observe histopathological changes in rat's internal organs. In the in-vitro study, maximum release was 95.38 ± 4.58% for AZM-NF, 72.79 ± 8.85% for AZM-CP, and 46.13 ± 8.19% for AZM-PD (p < 0.0001). The ex-vivo investigation revealed maximum permeation of 85.68 ± 5.87 for AZM-NF and 64.88 ± 5.87% for AZM-CP (p < 0.001). The in-vivo kinetics showed Cmax 0.738 ± 0.038, and 0.599 ± 0.082 µg/ml with Tmax of 4 and 2 h for AZM-NF and AZM-CP respectively (p < 0.01). Histopathological examination revealed compromised myocardial fibers integrity by AZM-CP only, liver and kidney showed mild aberrations by both formulations, with no remarkable changes in the rest of studied organs. The results showed that AZM-NF exhibited significantly enhanced bioavailability with comparative safer profile to AZM-CP investigated.

In Situ Lattice-Resolution Revelation of the Origins of Unexplored Anisotropic Sodiation Kinetics and Phase Transition in the Niobium Sulfide Anode.

Layered transition metal dichalcogenides (TMDs) have exhibited huge potential as anode materials for sodium-ion batteries. Most of them usually store sodium via an intercalation-conversion mechanism, but niobium sulfide (NbS2) may be an exception. Herein, through in situ transmission electron microscopy, we carefully investigated the insertion behaviors of Na ions in NbS2 and directly visualized anisotropic sodiation kinetics. Lattice-resolution imaging coupled with density functional theory calculations reveals the preferential diffusion of Na ions within layers of NbS2, accompanied by observable interlayer lattice expansion. Impressively, the Na-inserted layers can still withstand in situ mechanical testing. Further in situ observation vertical to the a/b plane of NbS2 tracked the illusive conversion reaction, which could result from interlayer gliding or wrinkling associated with stress accumulation. In situ electron diffraction measurements ruled out the possibility of such a conversion mechanism and identified a phase transition from pristine 3R-NbS2 to 2H-NaNbS2. Therefore, the NbS2 anode stores Na ions via only the intercalation mechanism, which conceptually differs from the well-known intercalation-conversion mechanism of typical TMDs. These findings not only decipher the whole sodiation process of the NbS2 anode but also provide valuable reference for unraveling the precise sodium storage mechanism in other TMDs.

Identification of heparin interaction sites on thrombin-activatable fibrinolysis inhibitor that modulate plasmin-mediated activation, thermal stability, and antifibrinolytic potential.

Background: Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen that provides a molecular link between coagulation and fibrinolysis. Studies have shown that the presence of glycosaminoglycans accelerates TAFI activation by plasmin and stabilizes activated TAFI (TAFIa). Objectives: We aimed to define the elements of TAFI structure that allow these effects. Methods: Based on crystallographic studies and homology to heparin-binding proteins, we performed mutagenesis of surface-exposed charged residues on TAFI that putatively constitute heparin-binding sites. We determined heparin binding, kinetics of activation by plasmin in the presence or absence of heparin, thermal stability, and antifibrinolytic potential of each variant. Results: Mutagenesis of Lys211 and Lys212 did not impair heparin binding but affected the ability of TAFI to be activated by plasmin. Mutagenesis of Lys306 and His308 did not impair heparin binding, but mutation of His308 had a severe negative effect on TAFI/TAFIa function. Mutation of Arg320 and Lys324 in combination markedly decreased heparin binding but had no effect on heparin-mediated acceleration of TAFI activation by plasmin while somewhat decreasing TAFIa stabilization by heparin. Mutagenesis of Lys327 and Arg330 decreased (but did not eliminate) heparin binding while decreasing the ability of heparin to accelerate plasmin-mediated TAFI activation, stabilize TAFIa, and increase the antifibrinolytic ability of TAFIa. A quadruple mutant of Arg320, Lys324, Lys327, and Arg330 completely lost heparin-binding ability and stabilization of the enzyme by heparin. Conclusion: Basic residues in the dynamic flap of TAFIa define a functionally relevant heparin-binding site, but additional heparin-binding sites may be present on TAFI.

Pre-Intercalation of TMA Cations in MoS2 Interlayers for Fast and Stable Zinc Ion Storage.

Applications of aqueous zinc ion batteries (ZIBs) for grid-scale energy storage are hindered by the lacking of stable cathodes with large capacity and fast redox kinetics. Herein, the intercalation of tetramethylammonium (TMA+) cations is reported into MoS2 interlayers to expand its spacing from 0.63 to 1.06 nm. The pre-intercalation of TMA+ induces phase transition of MoS2 from 2H to 1T phase, contributing to an enhanced conductivity and better wettability. Besides, The calculation from density functional theory indicates that those TMA+ can effectively shield the interactions between Zn2+ and MoS2 layers. Consequently, two orders magnitude high Zn2+ ions diffusion coefficient and 11 times enhancement in specific capacity (212.4 vs 18.9 mAh g‒1 at 0.1 A g‒1) are achieved. The electrochemical investigations reveal both Zn2+ and H+ can be reversibly co-inserted into the MoS2-TMA electrode. Moreover, the steady habitat of TMA+ between MoS2 interlayers affords the MoS2-TMA with remarkable cycling stability (90.1% capacity retention after 2000 cycles at 5.0 A g‒1). These performances are superior to most of the recent zinc ion batteries assembled with MoS2 or VS2-based cathodes. This work offers a new avenue to tuning the structure of MoS2 for aqueous ZIBs.

Microliter Whole Blood Neutrophil Assay Preserving Physiological Lifespan and Functional Heterogeneity.

For in vitro neutrophil functional assays, neutrophils are typically isolated from whole blood, having the target cells exposed to an artificial microenvironment with altered kinetics. Isolated neutrophils exhibit limited lifespans of only a few hours ex vivo, significantly shorter than the 3-5 day lifespan of neutrophils in vivo. In addition, due to neutrophils' inherently high sensitivity, neutrophils removed from whole blood exhibit stochastic non-specific activation that contributes to assay variability. Here, a method - named "µ-Blood" - is presented that enables functional neutrophil assays using a microliter of unprocessed whole blood. µ-Blood allows multiple phenotypic readouts of neutrophil function (including cell/nucleus morphology, motility, recruitment, and pathogen control). In µ-Blood, neutrophils show sustained migration and limited non-specific activation kinetics (<0.1% non-specific activation) over 3-6 days. In contrast, neutrophils isolated using traditional methods show increased and divergent activation kinetics (10-70% non-specific activation) in only 3 h. Finally, µ-Blood allows the capture and quantitative comparison of distinct neutrophil functional heterogeneity between healthy donors and cancer patients in response to microbial stimuli with the preserved physiological lifespan over 6 days.

Single-stranded DNA binding protein hitches a ride with the Escherichia coli YoaA-χ helicase.

The Escherichia coli XPD/Rad3-like helicase, YoaA, and DNA polymerase III subunit, χ, are involved in E. coli DNA damage tolerance and repair. YoaA and χ promote tolerance to the DNA chain-terminator, 3 -azidothymidine (AZT), and together form the functional helicase complex, YoaA-χ. How YoaA-χ contributes to DNA damage tolerance is not well understood. E. coli single-stranded DNA binding protein (SSB) accumulates at stalled replication forks, and the SSB-χ interaction is required to promote AZT tolerance via an unknown mechanism. YoaA-χ and SSB interactions were investigated in vitro to better understand this DNA damage tolerance mechanism, and we discovered YoaA-χ and SSB have a functional interaction. SSB confers a substrate-specific effect on the helicase activity of YoaA-χ, barely affecting YoaA-χ on an overhang DNA substrate but inhibiting YoaA-χ on forked DNA. A paralog helicase, DinG, unwinds SSB-bound DNA in a similar manner to YoaA-χ on the substrates tested. Through use of ensemble experiments, we believe SSB binds behind YoaA-χ relative to the DNA ds/ss junction and show via single-molecule assays that SSB translocates along ssDNA with YoaA-χ. This is, to our knowledge, the first demonstration of a mechanoenzyme pulling SSB along ssDNA.

Dependence of the formation kinetics of carbon dioxide hydrate on clay aging for solid carbon dioxide storage.

Clay-based marine sediments have great potential for safe and effective carbon dioxide (CO2) encapsulation by storing enormous amounts of CO2 in solid gas hydrate form. However, the aging of clay with time changes the surface properties of clay and complicates the CO2 hydrate formation behaviors in sediments. Due to the long clay aging period, it is difficult to identify the role of clay aging in the formation of CO2 hydrate in marine sediments. Here, we used ultrasonication and plasma treatment to simulate the breakage and oxidation of clay nanoflakes in aging and investigated the influence of clay aging on CO2 hydrate formation kinetics. We found that the breakage and oxidation of clay nanoflakes would disrupt the siloxane rings and graft hydroxyl on the clay nanoflakes. This decreased the negative charge density of clay nanoflakes and weakened the interfacial interaction of clay nanoflakes with the surrounding water. Therefore, the small clay nanoflakes enriched in hydroxyl would disrupt the surrounding tetrahedral water structure analogous to the CO2 hydrate, resulting in the prolongation of CO2 hydrate nucleation. These results revealed the influence of the structure-function relationship of clay nanoflakes with CO2 hydrate formation and are favorable for the development of hydrate-based CO2 storage.

Phosphorus recovery via struvite crystallization in batch and fluidized-bed reactors: Roles of microplastics and dissolved organic matter.

Struvite crystallization, a promising technology for nutrient recovery from wastewater, is facing considerable challenges due to the presence of emerging contaminants such as microplastics (MPs) ubiquitously found in wastewater. Here, we investigate the roles of MPs and humic acid (HA) in struvite crystallization in batch and fluidized-bed reactors (FBRs) using synthetic and real wastewater with a Mg:N:P molar ratio of 1:3:(1-1.3) at an initial pH of 11. Batch reactor (BR) experiment results show that MPs expedited the nucleation and growth rates of struvite (e.g., the rate of crystal growth in the presence of 30 mg L-1 of polyethylene terephthalate (PET) was 1.43 times higher than that in the blank system), while HA hindered the formation of struvite. X-ray diffraction and the Rietveld refinement analysis revealed that the presence of MPs and HA can result in significant changes in phase compositions of the reclaimed precipitates, with over 80 % purity of struvite found in the precipitates from suspensions in the presence of 30 mg L-1 of MPs. Further characterizations demonstrated that MPs act as seeds of struvite nucleation, spurring the formation of well-defined struvite, while HA favors the formation of newberyite rather than struvite in both reactors. These findings highlight the need for a more comprehensive understanding of the interactions between emerging contaminants and struvite crystallization processes to optimize nutrient recovery strategies for mitigating their adverse impact on the quality and yield of struvite-based fertilizers. ENVIRONMENTAL IMPLICATION: The presence of microplastics in wastewater poses a significant challenge to struvite crystallization for nutrient recovery, as it accelerates nucleation and growth rates of struvite crystals. This can lead to changes in the phase compositions of the reclaimed precipitates, with implications for the quality and yield of struvite-based fertilizers. Additionally, the presence of humic acid hinders the formation of struvite, favoring the formation of other minerals like newberyite. Understanding the interactions between emerging contaminants and struvite crystallization processes is crucial for optimizing nutrient recovery strategies and mitigating the environmental impact of these contaminants on water quality and struvite-based fertilizers.

Ultraclean Suspended Graphene by Radiolysis of Adsorbed Water.

Access to intrinsic properties of a 2D material is challenging due to the absence of a bulk that would dominate over surface contamination, and this lack of bulk also precludes effective conventional cleaning methods that are almost always sacrificial. Suspended graphene and carbon contaminants represent the most salient challenge. This work has achieved ultraclean graphene, attested by electron energy loss (EEL) spectra unprecedentedly exhibiting fine-structure features expected from bonding and band structure. In the cleaning process in a transmission electron microscope, radicals generated by radiolysis of intentionally adsorbed water remove organic contaminants, which would otherwise be feedstock of the notorious electron irradiation induced carbon deposition. This method can be readily adapted to other experimental settings and other materials to enable previously inhibited undertakings that rely on the intrinsic properties or ultimate thinness of 2D materials. Importantly, the method is surprisingly simple and robust, easily implementable with common lab equipment.

Unveiling microbial community structure and metabolic pathway over carbon cloth-titanium nitride-polyaniline biocathode for effective dichloromethane transformation.

Chlorinated volatile organic compounds (Cl-VOCs) have dramatically biotoxicity and environmental persistence due to the presence of chlorine atoms, seriously jeopardizing ecological security and human health. Dichloromethane (DCM) as a model pollutant, is widely applied in solvents, extractants and cleaning agents in the pharmaceutical, chemical and food industries. In this study, highly biocompatible and conductive carbon cloth-titanium nitride-polyaniline (CC-TiN-PANI) bioelectrodes were obtained for DCM degradation in microbial electrolysis cell (MEC). The good adhesion of TiN and PANI on the electrode surface was demonstrated. The degradation kinetics were fitted by the Haldane model, compared to the CC bioelectrode (0.8 h-1), the proportion of maximum degradation rates to half-saturation concentration (Vmax/Km) of CC-TiN (1.4 h-1) and CC-TiN-PANI (2.2 h-1) bioelectrodes were enhanced by 1.8 and 2.8 times, respectively. Microbial community structure analysis illuminated that the dominant genera on the biofilm were Alicycliphilus and Hyphomicrobium, and the abundance was enhanced significantly with the modification of TiN and PANI. The dechlorination of DCM to formaldehyde could be catalyzed by DCM dehalogenase (DcmA) or by haloalkane dehalogenase (DhlA). And further oxidized to formate: 1) direct catalyzed by formaldehyde dehydrogenase (FdhA); 2) conjugated with glutathione by S-(hydroxymethyl)-glutathione synthase (Gfa), S-(hydroxymethyl)-glutathione dehydrogenase (FrmA) and S-formyl-glutathione hydrolase (FrmB); 3) conjugation with tetrahydrofolate (H4F) and/or tetrahydromethanopterin.

A pH-dependent shift of redox cofactor specificity in a benzyl alcohol dehydrogenase of aromatoleum aromaticum EbN1.

We characterise a reversible bacterial zinc-containing benzyl alcohol dehydrogenase (BaDH) accepting either NAD+ or NADP+ as a redox cofactor. Remarkably, its redox cofactor specificity is pH-dependent with the phosphorylated cofactors favored at lower and the dephospho-forms at higher pH. BaDH also shows different steady-state kinetic behavior with the two cofactor forms. From a structural model, the pH-dependent shift may affect the charge of a histidine in the 2'-phosphate-binding pocket of the redox cofactor binding site. The enzyme is phylogenetically affiliated to a new subbranch of the Zn-containing alcohol dehydrogenases, which share this conserved residue. BaDH appears to have some specificity for its substrate, but also turns over many substituted benzyl alcohol and benzaldehyde variants, as well as compounds containing a conjugated C=C double bond with the aldehyde carbonyl group. However, compounds with an sp3-hybridised C next to the alcohol/aldehyde group are not or only weakly turned over. The enzyme appears to contain a Zn in its catalytic site and a mixture of Zn and Fe in its structural metal-binding site. Moreover, we demonstrate the use of BaDH in an enzyme cascade reaction with an acid-reducing tungsten enzyme to reduce benzoate to benzyl alcohol. KEY POINTS: •Zn-containing BaDH has activity with either NAD + or NADP+ at different pH optima. •BaDH converts a broad range of substrates. •BaDH is used in a cascade reaction for the reduction of benzoate to benzyl alcohol.

Clinical characteristics, viral dynamics, and antibody response of monkeypox virus infections among men with and without HIV infection in Guangzhou, China.

Background: Monkeypox virus (MPXV) is spreading globally and nearly half of the infected people were human immunodeficiency virus (HIV) positive. Therefore, an in-depth understanding of the effects of HIV infection on the outcomes of MPXV infection is urgently needed. This study aimed to explore the clinical features, viral dynamics, and antibody response to MPXV infections in men who had sex with men (MSM) with and without HIV co-infection. Design or methods: MPXV-infected patients diagnosed by PCR were recruited in this study and were divided into MPXV and MPXV + HIV groups based on whether they were co-infected with HIV. Clinical data and samples were collected during of the hospital stay and follow up interviews. The symptoms and signs, laboratory examinations, viral shedding in various body fluids or swabs, antibody dynamics were tracked and compared between the two groups. Results: A total of 41 MPXV patients were recruited through June 2023 to September 2023 in Guangzhou. The MPXV group and MPXV + HIV group comprised 20 and 21 MSM, respectively. Patients in the two groups exhibited similar clinical characteristics except for pruritus and eschar, both were significantly fewer in MPXV + HIV group than in MPXV only group. Among the 355 clinical samples collected, MPXV DNA was detected in 100% of scabs, 97.4% of skin swabs, and 92.3% of exudate swabs from lesions, while the positive rate was 87.5% from oropharyngeal swabs, 59% from saliva, 51.3% from anal swabs, 50% from feces, 30.6% from urine samples, 37.5% of semen, and 28.2% from sera. Dynamics analysis revealed that viral DNA was undetectable in most patients 20 days after symptom onset. IgM and IgG antibodies to MPXV were detected in all patients with 3-5 days earlier in the MPXV group than in the MPXV + HIV group. Conclusion: This cohort analysis based on a large outbreak among MSM in Guangzhou indicated no obvious differences in clinical symptoms, viral DNA data, but antibody responses were 3-5 days later in mpox patients with HIV infection.

Mn/carbon aerogels derived from the water-induced self-assembly of UIO-66 (Mn) for the thermal decomposition of ammonium perchlorate.

In solid propellants, combustion catalysts play a crucial role. Here, we introduce a convenient method for the self-assembly of UIO-66 (Mn) in the presence of water, leading to the preparation of Mn/C aerogels. The aerogels were successfully utilized in the thermocatalytic decomposition of ammonium perchlorate (AP). The results indicate that the incorporation of 2% mass fraction of Mn/C aerogels enhances the peak temperature of AP decomposition by approximately 87.5°C. Mn/C aerogels demonstrate excellent catalytic performance. In combination with kinetics, we propose a thermal catalytic mechanism.

In Situ Induced Interface Engineering in Hierarchical Fe3O4 Enhances Performance for Alkaline Solid-State Energy Storage.

Rechargeable aqueous batteries adopting Fe-based materials are attracting widespread attention by virtue of high-safety and low-cost. However, the present Fe-based anodes suffer from low electronic/ionic conductivity and unsatisfactory comprehensive performance, which greatly restrict their practicability. Concerning the principle of physical chemistry, fabricating electrodes that could simultaneously achieve ideal thermodynamics and fast kinetics is a promising issue. Herein, hierarchical Fe3O4@Fe foam electrode with enhanced interface/grain boundary engineering is fabricated through an in situ self-regulated strategy. The electrode achieves ultrahigh areal capacity of 31.45 mA h cm-2 (50 mA cm-2), good scale application potential (742.54 mA h for 25 cm2 electrode), satisfied antifluctuation capability, and excellent cycling stability. In/ex situ characterizations further validate the desired thermodynamic and kinetic properties of the electrode endowed with accurate interface regulation, which accounts for salient electrochemical reversibility in a two-stage phase transition and slight energy loss. This work offers a suitable strategy in designing high-performance Fe-based electrodes with comprehensive inherent characteristics for high-safety large-scale energy storage.

Synergistic adsorption of methylene blue using ternary composite of phosphoric acid geopolymer, calcium alginate, and sodium lauryl sulfate.

The removal of dyes from the aquatic ecosystem is necessary being a major threat to life. For enhanced remediation of methylene blue (MB) dye, a new ternary biopolymer-geopolymer-surfactant composite adsorbent is synthesized by combining phosphoric acid geopolymer (PAGP), calcium alginate (Alg), and sodium lauryl sulfate (SLS). During the synthesis of the composites, PAGP and SLS were mixed with the alginate matrix, producing porous hybrid beads. The PAGP-SLS-alginate (PSA) beads prepared were characterized using different analytical tools, i.e., scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR), X-ray diffractometry (XRD), surface area and porosimetery (SAP), and thermogravimetric analysis (TGA). To ascertain the ideal conditions for the adsorption process, a batch reactor procedure was used to investigate the effects of several parameters on MB adsorption, including pH (2, 4, 6, 8, 10), PSA adsorbent dosage (0.06-0.12 g), MB concentration (50-500 mg/L), contact time (15 to 300 min), and temperature (25, 35, and 45 °C). The SEM investigation indicated that ~ 1860 µm-sized PSA beads with 6-8 µm voids are generated. Based on XRD, FTIR, and SAP examinations, the material is amorphous, having numerous functional groups and an average pore size of 6.42 nm. Variation of pH has a little effect on the adsorption process, and the pH of 7.44 was found to be the pHpzc of the PSA beads. According to the findings of the batch study, equilibrium adsorption was obtained in 270-300 min, showing that the adsorption process was moderately slow-moving and effective. The dye adsorption linearly increased with initial dye concentration over concentration range of 50-500 mg/L and reciprocally decreased with rise in temperature. 0.06 g adsorbent dose, 25 °C, pH10, and 270 min were found to be the better conditions for adsorption experiments. Langmuir isotherm fitted well compared to Freundlich, Temkin, and Dubinin-Radushkevich (DR) isotherm models on the experimental data, and the maximum adsorption capacity(qmax) calculated was 1666.6 mg. g-1. Pseudo-second-order (PSO) kinetics model and multi steps (two) intra particle diffusion (IPD) model fitted well on the adsorption kinetics data. The system's entropy, Gibbs free energy, and change in enthalpy were measured and found to be -109.171 J. mol-1. K-1, - 8.198 to - 6.014 kJ. mol-1, and - 40.747 kJ. mol-1. Thermodynamics study revealed that adsorption process is exothermic, energetically favorable and resulting in the decrease in randomness. Chemisorption is found to be the dominant mechanism as confirmed by pH effect, Langmuir isotherm, PSO kinetics, IPD model, and thermodynamics parameters. PSA beads were successfully regenerated using ethanol in a course of 120 min and re-used for five times. To sum up, the PSA adsorbent's impressive adsorption capability of 1666.66 mg/g highlights its potential as a successful solution for methylene blue removal. The results of this study add to the expanding corpus of information on sophisticated adsorption materials and demonstrate PSA's potential for real-world uses in wastewater treatment and environmental clean-up.

Biochemical, kinetic, and structural characterization of a Bacillus tequilensis nitroreductase.

Nitroreductases (NRs) are NAD(P)H-dependent flavoenzymes that reduce nitro aromatic compounds to their corresponding arylamines via the nitroso and hydroxylamine intermediates. Because of their broad substrate scope and versatility, NRs have found application in multiple fields such as biocatalysis, bioremediation, cell-imaging and prodrug activation. However, only a limited number of members of the broad NR superfamily (> 24 000 sequences) have been experimentally characterized. Within this group of enzymes, only few are capable of amine synthesis, which is a fundamental chemical transformation for the pharmaceutical, agricultural, and textile industries. Herein, we provide a comprehensive description of a recently discovered NR from Bacillus tequilensis, named BtNR. This enzyme has previously been demonstrated to have the capability to fully convert nitro aromatic and heterocyclic compounds to their respective primary amines. In this study, we determined its biochemical, kinetic and structural properties, including its apparent melting temperature (Tm) of 59 °C, broad pH activity range (from pH 3 to 10) and a notably low redox potential (-236 ± 1 mV) in comparison to other well-known NRs. We also determined its steady-state and pre-steady-state kinetic parameters, which are consistent with other NRs. Additionally, we elucidated the crystal structure of BtNR, which resembles the well-characterized Escherichia coli oxygen-insensitive NAD(P)H nitroreductase (NfsB), and investigated the substrate binding in its active site through docking and molecular dynamics studies with four nitro aromatic substrates. Guided by these structural analyses, we probed the functional roles of active site residues by site-directed mutagenesis. Our findings provide valuable insights into the biochemical and structural properties of BtNR, as well as its potential applications in biotechnology.

Catalytic effect of nickel oxide nanoparticles from Lupinus Albus extract on green synthesis and photocatalytic reduction of methylene blue: kinetics and mechanism.

Green synthesis of nanomaterials is advancing due to their ease of synthesis, cheapness, nontoxicity, and renewability. An environmentally friendly biogenic method has been developed for the green synthesis of nickel oxide nanoparticles (NiO NPs) using phytochemical-rich bioextract. They are rich in bioextract phenolics, flavonoids, and berberine. These phytochemicals successfully reduce and stabilize NiNO3 into NiO NPs. In this study, NiO NPs were synthesized by the green synthesis method from Lupinus Albus. Characterization of NiO NPs was carried out by TEM, XRD, SEM, UV, XRF, BET, and EDX analyses. According to XRD analysis, TEM results also support this, where the NiO NPs particle size diameter is 5 nm. It was determined by the Tauc equation that the band energy gap of NiO NPs is 1.69 eV. It was determined that the BET surface area of NiO NPs was 49.6 m2/g. NiO nanoparticles synthesized from Lupinus Albus extract by the green synthesis method were used as catalysts in the photocatalytic reduction of methylene blue with NaBH4. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that there was no color change in 48 h without a catalyst, and in the presence of NiO nanoparticle catalyst, methylene blue was reduced by 97% in 8 min. The kinetics of the photocatalytic reduction of methylene blue with NaBH4 is a pseudo-first-order kinetic model and the kinetic rate constant is determined as 0.66 min-1, indicating that the catalytic effect of NiO NPs is very high at this value. NiO NPs were used five times in the photocatalytic reduction of methylene blue with NaBH4 and it was determined that the reduction of methylene blue was over 90% in each use.

NiO nanoparticles were synthesized from Lupinus Albus extract by green synthesis, which is an easily applied, cost-effective, and environmentally friendly method. The synthesized NiO nanoparticles were characterized using various characterization techniques. NiO nanoparticles have a high catalytic effect in the photocatalytic reduction of methylene blue with NaBH₄. Photocatalytic reduction of methylene blue with uncatalyzed NaBH₄ could not be achieved, and 97% reduction of methylene blue was completed in 8 min in the presence of NiO nanoparticle catalyst.

A Flow Cytometry-Based Method for Assessing CAR Cell Binding Kinetics Using Stable CAR Jurkat Cells.

Chimeric antigen receptors (CARs) are synthetic fusion proteins that can reprogram immune cells to target specific antigens. CAR-expressing T cells have emerged as an effective treatment method for hematological cancers; despite this success, the mechanisms and structural properties that govern CAR responses are not fully understood. Here, we provide a simple assay to assess cellular avidity using a standard flow cytometer. This assay measures the interaction kinetics of CAR-expressing T cells and targets antigen-expressing target cells. By co-culturing stably transfected CAR Jurkat cells with target positive and negative cells for short periods of time in a varying effector-target gradient, we were able to observe the formation of CAR-target cell doublets, providing a readout of actively bound cells. When using the optimized protocol reported here, we observed unique cellular binding curves that varied between CAR constructs with differing antigen binding domains. The cellular binding kinetics of unique CARs remained consistent, were dependent on specific target antigen expression, and required active biological signaling. While existing literature is not clear at this time whether higher or lower CAR cell binding is beneficial to CAR therapeutic activity, the application of this simplified protocol for assessing CAR binding could lead to a better understanding of the proximal signaling events that regulate CAR functionality. Key features • Determines CAR receptor cellular interaction kinetics using a Jurkat cell model. • Can be used for a wide variety of CAR target antigens, including both hematological and solid tumor targets. • Experiments can be performed in under two hours with no staining using a standard flow cytometer. • Requires stable CAR Jurkat cells and target cells with stable fluorescent marker expression for optimal results.