Autocatalytic System Research Articles

PH and ROS Dual-Responsive Autocatalytic Release System Potentiates Immunotherapy of Colorectal Cancer.

The immunosuppressive microenvironment severely limits the responsiveness of colorectal cancer (CRC) to immunotherapy. Herein, a pH and reactive oxygen species (ROS) dual-responsive autocatalytic release system (TPDM/PGA) is constructed to reverse the immunosuppressive microenvironment and potentiate CRC immunotherapy. Dihydroartemisinin (DHA) and mitoxantrone (MTO) are conjugated to ROS-responsive polyethylenimine (TP) via a ROS-cleavable linker, respectively, and then coated with polyglutamic acid (PGA) to endow pH and ROS dual-responsiveness. The dissociation of PGA within the acidic TME facilitates its deep penetration and cell internalization, while the intracellular released DHA and MTO in response to high levels of H2O2 further produced a large amount of ROS, forming positive feedback to accelerate drug release and exacerbate oxidative stress. TPDM/PGA collaboratively reversed the immunosuppressive microenvironment and induced a strong anti-tumor immune response when combined with anti-PD-L1 antibody, significantly inhibiting tumor growth and prolonging the survival time of CT26 and MC38 tumor-bearing mice. The excellent therapeutic effect, together with the good tolerance, make TPDM/PGA a promising candidate for enhanced immunotherapy of colorectal cancer.

Rapid miRNA detection enhanced by exponential hybridization chain reaction in graphene field-effect transistors

Scalable electronic devices that can detect target biomarkers from clinical samples hold great promise for point-of-care nucleic acid testing, but still cannot achieve the detection of target molecules at an attomolar range within a short timeframe (<1 h). To tackle this daunting challenge, we integrate graphene field-effect transistors (GFETs) with exponential target recycling and hybridization chain reaction (TRHCR) to detect oligonucleotides (using miRNA as a model disease biomarker), achieving a detection limit of 100 aM and reducing the sensing time by 30-fold, from 15 h to 30 min. In contrast to traditional linear TRHCR, our exponential TRHCR enables the target miRNA to initiate an autocatalytic system with exponential kinetics, significantly accelerating the reaction speed. The resulting reaction products, long-necked double-stranded polymers with a negative charge, are effectively detected by the GFET through chemical gating, leading to a shift in the Dirac voltage. Therefore, by monitoring the magnitude of this voltage shift, the target miRNA is quantified with high sensitivity. Consequently, our approach successfully detects 22-mer miRNA at concentrations as low as 100 aM in human serum samples, achieving the desired short timeframe of 30 min, which is congruent with point-of-care testing, and demonstrates superior specificity against single-base mismatched interfering oligonucleotides.

One-tube target amplification-free CRISPR-Cas13 autocatalytic system

Clustered regularly interspaced short palindromic repeats (CRISPR) diagnostics have shown great promise for nucleic acid testing. However, CRISPR/Cas13a-based RNA sensing is hindered by the absence of accurate, fast and sensitive assays. Current Cas-based methods generally involve two separate steps: target-amplification and Cas-detection. This two-step method complicates detection, causes cross-contamination, and is difficult to deploy. Therefore, it is necessary to develop a facile one-step Cas13a-based RNA detection assay. We present a one-tube target amplification-free CRISPR-Cas13a autocatalytic circuit system that combines the Cas13a nuclease, T4 polynucleotide kinase, Bsu DNA polymerase and T7 RNA polymerase with a universally designed combinatorial DNA probe to create a one-pot assay for isothermal RNA detection. In this assay, after target RNA recognition, the cis-cleavage and trans-cleavage activities of Cas13 are activated, which leads to the initiation of a Cas13a autocatalytic reaction, resulting in an exponentially amplifying detection signal, thus enabling the detection of approximately 23.01 (95 % CI:16.95-41.23) copies/µL RNA in 45 min. A facile, easy-to-deploy, and one-tube Cas13a-based autocatalytic reaction system was constructed for rapid and highly sensitive RNA detection for the first time. This Cas13a-based autocatalytic system offers not only a versatile platform for directly detecting RNA targets but also a route toward point-of-care nucleic acid testing.

Aqueous AlCl3/ZnCl2 solution room-induced the self-growing strategy of expanded topological network for cellulose/polyacrylamide-based solid-state electrolytes

The green synthesis strategy for cellulose-containing hydrogel electrolytes is significant for effectively managing resources, energy, and environmental concerns in the contemporary world. Herein, we propose an all-green strategy using AlCl3/ZnCl2/H2O solvent to create cellulose/polyacrylamide-based hydrogel (AZ-Cel/PAM) with expanded hierarchical topologies. The aqueous AlCl3/ZnCl2 facilitates the efficient dissolution of cellulose at room temperature, and the dispersed Al3+-Zn2+ ions autocatalytic system catalyzes in-situ polymerization of acrylamide (AM) monomer. This expands the AM network within the cellulose framework, forming multiple bonding interactions and stable ion channels. The resulting hybrid hydrogel exhibits improved mechanical properties (tensile strength of 56.54 kPa and compressive strength of 359.43 kPa) and enhanced ionic conductivity (1.99 S/m). Furthermore, it also demonstrates excellent adhesion, freeze resistance (−45 °C), and water retention capabilities. Quantum simulations further clarify the mechanical composition and ion transport mechanism of AZ-Cel/PAM hydrogels. The assembled supercapacitor with the hydrogel electrolyte, demonstrates an ideal area-specific capacitance of 203.80 mF/cm2. This all-green strategy presents a novel approach to developing sustainable energy storage devices.

The Euler’s harmonic holomorphic regenerative universe

The Cartesian dualism is a precursor to Euler’s complex theory, that completes the Descartes-Leibnitz monadic conception using the natural quanta (non-splitting e, π) along with their topological torsion in the form of dual isomorphism. The complete Euler’s identity controls a bounded regenerative/ recurrent multiverse (a kind of multigraph) by two regenerative exponential functions, one quantic, e = exp (1) and another gravitational, g0 ≡ 10 = exp (1) with the fixed points, g0 = π2 and (g0g0) respectively. Physically, the fixed points give the well-defined the unit gravity (g0 m/s2) and light self-ignition velocity of a stable recurrent self-sustained process, provided the rate of mass production just equals the rate removal. This is the Euler’s fictitious regenerative universe - like our world, a quantum autocatalytic reaction system. The present paper describes such a system controlled by thermal gravitational waves, in the case the critical solar system.

Numerical Computations of Time-Dependent Auto-Catalytic Glycolysis Chemical Reaction-Diffusion System

A combined semi-discretized spectral matrix collocation algorithm based on (new) family of Krawtchouk polynomials is proposed to solve the time-dependent nonlinear auto-catalytic glycolysis reaction-diffusion system arising in mathematical chemistry. The first stage of the numerical algorithm is devoted to the Taylor series time advancement procedure yielding to a (linear and steady) system of ODEs. In the second stage and in each time frame, a matrix collocation technique based on the Krawtchouk polynomials is utilized to the resulting system of ODEs in an iterative manner. The results of the performed numerical experiments with Neumann boundary conditions are given to show the utility and applicability of the combined Taylor-Krawtchouk spectral collocation algorithm. The positive property of the glycolysis chemical model is sustained by the proposed algorithm and verified through comparisons with existing numerical methods in the literature. The combined technique is simple and flexible enough to easily produce the approximate solutions of diverse physical and applied models in engineering and science.

Visible light-driven and substrate-promoted alkenyltrifluoromethylation of alkenes to synthesize CF3-functionalized 1,4-naphthoquinones.

The first example of the visible light-driven and substrate-promoted three-component alkenyltrifluoromethylation of alkenes is developed. This approach uses easily available alkenes, 2-arylamino-1,4-naphthoquinones and Togni reagent as the reactants, and describes good functionality tolerance. The reaction offers a precise synthesis of valuable CF3-functionalized 1,4-naphthoquinones and can be applied in late-stage modification of natural products and pharmaceuticals. Experimental results imply that bifunctional 2-arylamino-1,4-naphthoquinones serve as both substrates and catalysts. In terms of this autocatalytic system, the protocol enables a straightforward intermolecular difunctionalization of alkenes under visible light irradiation without external catalysts.

Dynamic Bufurcation of a Tri-molecular Autocatalytic Reaction-diffusion System

The tri-molecular autocatalytic reaction-diffusion system is a class of model, which can reveal a variety of phenomena observed in areas of encompassing physics, biology, ecology, chemistry and many other fields. In this paper, the tri-molecular autocatalytic reaction-diffusion system with Neumann boundary condition is studied. First, We have reached the following conclusion: the equilibrium of the system loses stability if the parameter is greater than a fixed value, and the corresponding principle of exchange stability condition is then verified. Second, we obtained the local asymptotic stability of trivial, transition types, expressions of bifurcated solutions, the main tools are center manifold theory. The theory is used to reduce the infinite dynamical system to a finite dimensional. Finally, the necessary explanations for the theory is provided.

When patterns come to life: Comment on “Unified representation of Life's basic properties by a 3-species Stochastic Cubic Autocatalytic Reaction-Diffusion system of equations” by A.P. Muñuzuri and J. Pérez-Mercader

When patterns come to life: Comment on “Unified representation of Life's basic properties by a 3-species Stochastic Cubic Autocatalytic Reaction-Diffusion system of equations” by A.P. Muñuzuri and J. Pérez-Mercader

Information, computation, and causality in living systems: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations", by A.P. Muñuzuri and J. Pérez-Mercader.

Information, computation, and causality in living systems: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations", by A.P. Muñuzuri and J. Pérez-Mercader.

Effect of KMnO4 on the migration and transformation of Mn2+ and NH4+-N in electrolytic manganese residue: Autocatalytic system of manganese (Mn2+-MnO2-Mn2+)

Electrolytic manganese residue (EMR) leachate contains high concentrations of Mn2+, NH4+-N, and heavy metals, seriously damaging the ecological environment. In this study, the effects of different KMnO4 dosages on the migration and transformation of Mn2+ and NH4+-N in EMR were investigated. The results showed that KMnO4 accelerated the migration and transformation of Mn2+ and NH4+-N. Mn2+ was mainly converted to the new ecologically hydrated MnO2 (NEHMO), which adsorbed Mn2+ and then oxidized it to form new active manganese oxides, thus constructing an autocatalytic oxidation reaction system of manganese (Mn2+-MnO2-Mn2+). A part of NH4+-N adsorbed on the NEHMO surface was catalytically oxidized to NO3–-N and NO2–-N. Mn2+on the EMR surface of the KMnO4 system mainly existed in the form of Mn3+, and the manganese oxides formed by the autocatalytic oxidaton of manganese mainly existed in the EMR system in the Fe-Mn oxidation state and residue state. This study provides theoretical support for developing in-situ remediation technology for EMR in residue sites.

Conceptualizing life via non-equilibrium physics; is it enough?: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations" by A.P. Muñuzuri and J. Pérez-Mercader.

Conceptualizing life via non-equilibrium physics; is it enough?: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations" by A.P. Muñuzuri and J. Pérez-Mercader.

Self-adhesive frost-resistant conductive hydrogel electrolytes based on TA@WSCA-Zn autocatalytic system for flexible and foldable solid-state capacitors

In this study, we have successfully prepared a freeze-resistant conductive hydrogel with a fast polymerization rate and excellent mechanical and adhesive properties. In this paper, hydrogels capable of rapid polymerization in a short time were prepared based on the TA@WSCA-Zn (WSCA, water-soluble cellulose acetate; TA@WSCA, tannic acid-coated WSCA suspension; TA@WSCA-Zn, a certain amount of zinc chloride (ZnCl2) was added to TA@WSCA suspension;) autocatalytic system at room temperature or low temperature. TA@WSCA-Zn forms a stable reversible quinone-catechol redox reaction to activate the decomposition of ammonium persulfate (APS, initiator) to produce SO4−· radicals, which triggers the ultra-fast polymerization of amphoteric ([2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl), SBMA) and acrylic monomers (AA). To improve the frost resistance and electrical conductivity of the hydrogels, we also introduced amphoteric ions, which can provide migration channels for Zn2+ and greatly increase the migration rate. The TA@WSCA-7.5/PSA hydrogel (PSA, hydrogel prepared by polymerization of acrylic acid and SBMA as monomers;) can achieve tensile strength and toughness of 1.33 MPa and 4.89 MJ m−3. It can provide excellent electrical conductivity and interfacial adhesion over a temperature range of 25 to −60 °C. In addition, the supercapacitor assembled from the TA@WSCA-7.5/PSA hydrogel electrolyte still has good capacitance characteristics after folding and 10,000 charge/discharge cycles, with a capacitance retention of 93.33 % and an excellent cycle life. This autocatalytic system provides a new strategy and approach for the preparation of freeze-resistant conductive hydrogel electrolytes.

A rapid polymerization of flexible wearable hydrogels sensors with excellent mechanical property, conductivity and frost resistance performance based on double autocatalytic system

Recently, wearable services that are flexible and based on conductive hydrogels have rapidly evolved and found numerous applications. These conductive hydrogels must possess remarkable mechanical strength, electrical conductivity, and sensing stability, while also being able to withstand low temperatures. However, creating hydrogels that meet all these requirements can be a lengthy and complicated process. Herein, we quickly (10 s) generated a double network conductive hydrogels (PHTF@DNH) using the double autocatalytic system consisting of TA (Tannic acid) and Fe3+. Due to the hydrogen bonding interactions between polyacrylamide (PAM), chitosan quaternary ammonium salt (HACC), TA, cross-linking of N, N′-methylene-bis-acrylamide (MBA), and ionic conduction of sodium citrate (Na3Cit), the hydrogel exhibit excellent tensile property (stress of 177.40 kPa, elongation at break of 788%), compressive performance (compressive strength of 1.1 MPa at 80% deformation), desirable toughness (702.60 kJ/m3), and exceptional cyclic compression and swelling properties. The hydrogel-based sensors show exceptional electrical conductivity (59.02 mS/cm), sensitivity (GF value of 1.13 at 100–550% strain), broad detection range and good signal stability. Even at −30 °C, the hydrogels still maintained stable. Eventually, it is harmless to human skin. We believe that the PHTF@DNH offer a new approach to the manufacture of sensitive wearable electronic devices.

Numerical and renormalization group analysis of the phase diagram of a stochastic cubic autocatalytic reaction-diffusion system.

The renormalization group is a set of tools that can be used to incorporate the effect of fluctuations in a dynamical system as a rescaling of the system's parameters. Here, we apply the renormalization group to a pattern-forming stochastic cubic autocatalytic reaction-diffusion model and compare its predictions with numerical simulations. Our results demonstrate a good agreement within the range of validity of the theory and show that external noise can be used as a control parameter in such systems.

On the robustness of the Grey-Scott system as a minimal model of life: Comments on "Unified representation of Life's basic properties by a 3-species Stochastic Cubic Autocatalytic Reaction-Diffusion system of equations" by A. P. Muñuzuri and J. Pérez-Mercader.

On the robustness of the Grey-Scott system as a minimal model of life: Comments on "Unified representation of Life's basic properties by a 3-species Stochastic Cubic Autocatalytic Reaction-Diffusion system of equations" by A. P. Muñuzuri and J. Pérez-Mercader.

A novel recipe for prebiotic systems chemistry arising from autocatalytic relationships: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations", by A.P. Muñuzuri and J. Pérez-Mercader.

A novel recipe for prebiotic systems chemistry arising from autocatalytic relationships: Comment on "Unified representation of life's basic properties by a 3-species stochastic cubic autocatalytic reaction-diffusion system of equations", by A.P. Muñuzuri and J. Pérez-Mercader.

Multifunctional conductive hydrogels based on the alkali lignin-Fe3+-mediated Fenton reaction for bioelectronics

Requirements for sustainable development have led to the urgent need for low cost, green, and reproducible resources. Lignin is one of the resources meeting this requirement. Herein, an alkali lignin (AL)-Fe3+-H2O2 autocatalytic system was introduced to assemble multifunctional AL-Fe3+/polyacrylic acid (PAA) hydrogels. The AL-Fe3+ pair-mediated Fenton reaction can generate a large number of free radicals to accelerate gelation. Owing to the abundant hydrogen bonds and metal coordination bonds, the AL-Fe3+/PAA hydrogels possessed excellent mechanical properties (tensile strength of 38 kPa), adhesion properties (18 kPa for pigskin), and self-healing ability (78 % for tensile strength and 88 % for tensile modulus). In addition, hydrogel-based sensors with high durability, strain sensitivity, and fast response times were employed to accurately monitor motion or electrophysiological signals. Subsequently, a portable sensing device for the wireless and remote monitoring of a user's motion status was integrated. As a result, an AL-Fe3+-H2O2 autocatalytic system has great potential for use in hydrogel preparation in flexible bioelectronics and wearable sensors. It can promote the sustainable development of flexible bioelectronics.

Control of chaos and bifurcation by nonfeedback methods in an autocatalytic chemical system

AbstractNonfeedback methods of chaos and bifurcation control are suited for practical applications because of their speed, flexibility, no online monitoring, and processing requirements. In this paper, we analyze the control performance of various nonfeedback methods such as (i) adding a weak periodic force, (ii) adding a second periodic force, and (iii) adding a quasiperiodic force. We apply these methods to control chaos and bifurcation in an autocatalytic chemical system. By choosing the amplitudes of the external excitation as control parameters, we investigate what effect the amplitudes have on the dynamics of the chemical system with suitable system's parameters value. Controlling of chaotic and bifurcation behaviors has been investigated through the bifurcation diagram, phase portrait, and time series.

Analyses of Critical Hydrogen Enrichment in PWR Containment Compartments

During a loss-of-coolant accident in a pressurized water reactor (PWR), steam of varying quality is released from the primary circuit into the equipment compartments of the containment, followed by the release of a hydrogen-steam mixture during the core degradation phase. In the case of long-lasting accidents, findings of detailed code analyses indicate an enrichment of hydrogen in lower peripheral containment compartments in the reference PWR plant under investigation. During the late accident phase with ex-vessel molten core–concrete interaction, even in the case of an operating passive autocatalytic recombiner system, this poses a threat for local hydrogen combustion later on. Such hydrogen phenomena are not expected and have not been widely studied up to now. Therefore, corresponding experiments have been performed at the THAI test facility operated by Becker Technologies. One of these tests had been precalculated with the COntainment COde SYStem (COCOSYS) as part of the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) code system AC2 and has been used to validate the code. The 60-m3 THAI test vessel has been divided into an inner compartment that has been connected to the surrounding vessel, simulating the upper and peripheral containment part, by very small flow openings at the bottom representing the clearance between door frames and door leaves and one opening at the top representing typical openings by burst disks. The paper discusses both the experimental findings of a test series on the potential enrichment of hydrogen in lower containment compartments and the COCOSYS calculations demonstrating the applicability of the code under complex flow conditions including stratification phenomena.