Does climate policy uncertainty drive the extreme spillovers of carbon-energy-shipping markets?

In addressing the ramifications of climate change, the shipping industry, reliant on energy, has been integrated into the Emissions Trading System (ETS). This study utilizes the quantile connectedness model to investigate the information spillover mechanisms and extreme time-varying interconnections among carbon, energy, and shipping markets. Whether climate policy uncertainty drives the extreme interconnections is also discussed during both pre- and post-Paris Agreement periods, by using GARCH-MIDAS model. The empirical findings underscore the following key points: (i) the systemic connectedness is highly sensitive to market conditions and major events, increasing significantly under extreme market conditions; (ii) following the implementation of the Paris Agreement, an elevated level of informational interdependence has manifested between the carbon market and the energy and shipping sectors; (iii) the information transfer mechanism between carbon and shipping sectors creates direct and indirect spillover paths, with crude oil market mediating the indirect path; (iv) climate policy uncertainty greatly affects the extreme time-varying interconnections, and this impact has decreased after the Paris Agreement came into effect. These results offer valuable insights for market policymakers and shipping companies in achieving a balance between carbon emission reduction and shipping business, particularly amidst heightened climate policy uncertainty.

Unraveling Meso-Substituent Steric Effects on the Mechanism of Hydrogen Evolution Reaction in NiII Porphyrin Hydrides Using DFT Method.

Substituents at the meso-site of metalloporphyrins profoundly influence the hydrogen evolution reaction (HER) mechanism. This study employs density functional theory (DFT) to computationally analyze NiII-porphyrin and its hydrides derived from tetrakis(pentafluorophenyl)porphyrin molecules, presenting stereoisomers in ortho- or para-positions. The results reveal that the spatial resistance effect of meso-substituted groups at the ortho- and para-positions induces significant changes in Ni-N bond lengths, angles, and reaction dynamics. For ortho-position substituents forming complex I, a favorable 88.88 ų spherical space was created, facilitating proton coordination and the formation of H2 molecules; conversely, para-position substituents forming complex II impeded H2 formation until bimolecular complexes arose. Molecular dynamics (MD) analysis and comparison were conducted on the intermediation products of I-H2 and (II-H)2, focusing on the configuration and energy changes. In the I-H2 products, H2 molecules underwent separation after 150 fs and overcame the 2.2 eV energy barrier. Subsequently, significant alterations in the spatial structure were observed as complex I deformed. In the case of (II-H)2, it was influenced by the distinctive "sandwich" configuration; the spatial structure necessitated overcoming a 6.7 eV energy barrier for H2 detachment and a process observed after 2400 fs.

Light-Up Aptameric Sensor of Serotonin for Point-of-Care Use.

Serotonin is a vital neurotransmitter for regulating organism functions, and its abnormal level indicates multiple diseases. Aptamer has emerged as an innovative tool for serotonin analysis very recently; however, the current aptameric sensing platform lacks design flexibility and portability. Here, we introduce a light-up aptameric sensor using designer DNA molecules with tunable affinity and dynamic response and achieve mobile phone-based detection for point-of-care use. We develop a type of allosteric DNA sensor through flanking the serotonin recognition domain with split fluorogenic sequences, where both linker lengths and split sites of the aptamer affect its function. In addition, we design a series of molecular constructs that contain nucleotide mutations and systematically investigate the structure folding and ligand binding of the aptameric molecules. The results show distinct effects of variant mutation sites on conformation change and sensing responses. Notably, the variable aptameric molecules allow affinity and dynamic response regulation, which are adaptable to diverse sensing applications that require different threshold levels. Furthermore, we demonstrate a simple surface-based assay that can use smartphone imaging to visualize results for diagnosis. In a portable and simple manner, highly sensitive and selective serotonin assay is achieved in different biofluids, with detection limits in the low nanomolar range. This study offers an alternative approach for serotonin assay using engineered aptameric molecular probes. We expect that the practical utility may make the method promising in resource-limited settings.

Experimental and Theoretical Study on Crown Ether-Appended-Fe(III) Porphyrin Complexes and Catalytic Oxidation Cyclohexene with O2.

Modifying non-precious metal porphyrins at the meso-position is sufficient to further improve the ability to activate O2 and the selectivity of the corresponding redox products. In this study, a crown ether-appended Fe(III) porphyrin complex (FeTC4PCl) was formed by replacing Fe(III) porphyrin (FeTPPCl) at the meso-position. The reactions of FeTPPCl and FeTC4PCl catalysed by O2 oxidation of cyclohexene under different conditions were studied, and three main products, 2-cyclohexen-1-ol (1), 2-cyclohexen-1-one (2), and 7-oxabicyclo[4.1.0]heptane (3), were obtained. The effects of reaction temperature, reaction time, and the addition of axial coordination compounds on the reactions were investigated. The conversion of cyclohexene reached 94% at 70 °C after 12 h, and the selectivity toward product 1 was 73%. The geometrical structure optimization, molecular orbital energy level analysis, atomic charge, spin density, and density of orbital states analysis of FeTPPCl, FeTC4PCl, as well as the oxygenated complexes (Fe-O2)TCPPCl and (Fe-O2)TC4PCl formed after adsorption of O2, were carried out using the DFT method. The results of thermodynamic quantity variation with reaction temperature and Gibbs free energy variation were also analysed. Finally, based on experimental and theoretical analysis, the mechanism of the cyclohexene oxidation reaction with FeTC4PCl as a catalyst and O2 as an oxidant was deduced, and the reaction mechanism was obtained as a free radical chain reaction process.

Effect of Kushen (Radix Sophorae flavescentis) extract on laryngeal neoplasm Hep2 cells.

OBJECTIVE: To evaluate the effect of fermented extract of Kushen (Radix Sophorae Flavescentis) or non-fermented ESF on laryngeal neoplasms Hep2 cells. METHODS: Use 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay to explore the effect of fermented ESF and non-fermented ESF on Hep2 cells, and detect the mRNA and protein expression level of Bcl-2, Bax and Caspase-3 with reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Both fermented ESF and non-fermented ESF could inhibit laryngeal neoplasm's Hep2 cells, but and the cells did not response to the dilution 1: 320 of fermented ESF, nor to the 1:1280 dilution of non-fermented ESF. As time progressed, the dilution 1:80 of fermented ESF and 1:320 dilution of non-fermented ESF could significantly reduce Bcl-2 mRNA and protein expression and down-regulate Caspase-3 mRNA and protein expression. Bax mRNA and protein were not expressed in Hep2 cells. CONCLUSIONS: Both fermented ESF and non-fermented ESF could inhibit the proliferation of Hep2 cells, and the effect of non-fermented ESF was significantly better than that of the fermented.

[Preparation of Kushen-Dilong nanoemulsion gel and transdermal characterization in vitro].

OBJECTIVE: To prepare Kushen-Dilong nanoemulsion and nanoemuls-ion gel, and investigate its content, physical and chemical properties. Their transdermal properties in vitro were studied as well. METHOD: IPM acted as oil phase, EL35 as surfactant, EtOH as cosurfactant, Pheretima aqueous solution was added dropwise to the oil phase to prepare Kushen-Dilong nanoemulsion at room temperature using magnetic stirring. HPLC was used to determine the content of matrine and oxymatrine in the nanoemulsion. Transmission electron microscopy and laser particle size analyzer was used to determine the shape and size of the nanoemulsion. NP700 was used as substrate to prepare Kushen-Dilong nanoemulsion gel. Franz diffusion cell was used for the nanoemulsion and gel transdermal characteristics in vitro. RESULT: The Kushen-Dilong nanoemulsion was O/W nanoemulsion, its uniform particle size was 20.6 nm with roundness appearance and stable content. The steady-state permeation rate of Kushen-Dilong nanoemulsion, nanoemulsion gel, saturated aqueous solution, hydro gel were 0.1484, 0.1183, 0.0306, 0.0321 mg x cm(-2) x h(-1), respectively. CONCLUSION: The 24 h cumulative infiltration and infiltration rate of Kushen-Dilong nanoemulsion and nanoemulsion gel were better than the saturated aqueous solution and hydro gel, which could provide a new dosage form for Kushen-Dilong transdermal drug delivery.

[Physicochemical properties and skin penetration in vitro of total alkaloids of Sophora flavescens nanoemulsion].

The research aimed at investigating the physicochemical properties, stability and skin penetration in vitro of total alkaloids of Sophora flavescens nanoemulsion. Prepare total alkaloids of S. flavescens nanoemulsion and detect the determination of matrine and oxymatrine in the nanoemulsion using HPLC method. Transmission electron microscopy and laser particle size analyzer were utilized to detect the shape and size of the nanoemulsion respectively. And also the stability of nanoemulsion was studied under the conditions of low temperature (4 degrees C), normal temperature (25 degrees C) and high temperature (60 degrees C). Franz diffusion cell was used to research the transdermal absorption of nanoemulsion in vitro. The results found that the nanoemulsion we prepared presented appearance of rounded, uniform; its average diameter was (15.55 +/- 2.24) nm, and particle size distribution value was 0. 161; the appearance, diameter and percentage determination of total alkaloids of S. flavescens had no variations after 15 d under 4, 25, 60 degrees C respectively. The steady-state permeation rate was 4.564 1 microg x cm(-2) x h(-1), 24 h cumulative amount of penetration was 110.7 microg x cm(-2), which was 1.86 fold of 24 h cumulative amount of aqueous solution (59.41 microg x cm(-2)). All the results demonstrated total alkaloids of S. flavescens nanoemulsion had good permeability, and could provide a new preparation for its clinical application.

High-fidelity ATP imaging via an isothermal cascade catalytic amplifier.

Artificial catalytic DNA circuits that can identify, transduce and amplify the biomolecule of interest have supplemented a powerful toolkit for visualizing various biomolecules in cancer cells. However, the non-specific response in normal tissues and the low abundance of analytes hamper their extensive biosensing and biomedicine applications. Herein, by combining tumor-responsive MnO2 nanoparticles with a specific stimuli-activated cascade DNA amplifier, we propose a multiply guaranteed and amplified ATP-sensing platform via the successive cancer-selective probe exposure and stimulation procedures. Initially, the GSH-degradable MnO2 nanocarrier, acting as a tumor-activating module, ensures the accurate delivery of the cascade DNA amplifier into GSH-rich cancer cells and simultaneously provides adequate Mn2+ cofactors for facilitating the DNAzyme biocatalysis. Then, the released cascade amplifier, acting as an ATP-monitoring module, fulfills the precise and sensitive analysis of low-abundance ATP in cancer cells where the catalyzed hairpin assembly (CHA) is integrated with the DNAzyme biocatalyst for higher signal gain. Additionally, the cascade catalytic amplifier achieved tumor-specific activated photodynamic therapy (PDT) after integrating an activatable photosensitizer into the system. This homogeneous cascade catalytic aptasensing circuit can detect low-abundance endogenous ATP of cancer cells, due to its intrinsically rich recognition repertoire and avalanche-mimicking hierarchical acceleration, thus demonstrating broad prospects for analyzing clinically important biomolecules and the associated physiological processes.

Progress of Stimuli-Responsive Nanoscale Metal Organic Frameworks as Controlled Drug Delivery Systems.

BACKGROUND: Development of controlled drug delivery systems can improve the pharmacokinetic characteristics of drug molecules in the human body, thereby significantly improving the utilization rate of drugs and reducing toxicity and side effects caused by their high concentrations, which can occur when delivery is not controlled. Metal organic frameworks are a new class of very promising crystalline microporous materials, especially when the size is reduced to the nanometer range. Metal-organic frameworks exhibit large specific surface areas, tunable compositions, and easy functionalization. In recent years, an increasing number of studies have reported the remarkable advances in multifunctional nanoscale metal-organic frameworks in drug delivery. OBJECTIVE: To review the latest research involving advances in stimuli-responsive nanoscale metal organic frameworks as drug delivery systems in controlled-release drugs. DISCUSSION: We first introduce the two main strategies associated with nanoscale metal organic frameworks used in drug loading: direct assembly and post-encapsulation. We next focus on the latest discoveries of nanoscale metal-organic framework-based stimulus response systems for drug delivery, including pH, magnetics, light, ion, temperature, and other stimuli, as well as multiple stimulus- responsive drug delivery systems. Finally, we discuss the challenges and future developmental directions of nanoscale metal-organic framework-based controlled drug release.

Synthesis of a hierarchical carbon fiber@cobalt ferrite@manganese dioxide composite and its application as a microwave absorber.

In this study, a novel hierarchical carbon fiber@cobalt ferrite@manganese dioxide (CF@CoFe2O4@MnO2) composite was facilely prepared via a sol-gel method and hydrothermal reaction. The morphology, structure, chemical and element composition, crystal form, elemental binding energy, magnetic behavior and microwave absorbing performance of the composite were carefully investigated. According to its hysteresis loops, the composite exhibits a typical soft magnetic behavior, with a M s value of 30.2 emu g-1. Besides, the as-synthesized CF@CoFe2O4@MnO2 composite exhibits superior microwave absorption performance mainly due to reasonable electromagnetic matching, and its minimum reflection loss value can reach -34 dB with a sample thickness of just 1.5 mm. The composite can be regarded as an ideal microwave absorber.

Preparation and Characterization of Epoxy Resin Filled with Ti3C2Tx MXene Nanosheets with Excellent Electric Conductivity.

MXene represents new kinds of two-dimensional material transition metal carbides and/or carbonitrides, which have attracted much attention in various applications including electrochemical storage devices, catalysts, and polymer composite. Here, we report a facile method to synthesize Ti3C2Tx MXene nanosheets and prepare a novel electrically conductive adhesive based on epoxy resin filled with Ti3C2Tx MXene nanosheets by solution blending. The structure, morphology, and performance of Ti3C2Tx MXene nanosheets and epoxy/Ti3C2Tx MXene nanosheets composite were investigated. The results show that Ti3C2Tx MXene possesses nanosheet structure. Ti3C2Tx MXene nanosheets were homogeneously dispersed in epoxy resin. Electrical conductivity and mechanical properties measurements reveal that the epoxy/Ti3C2Tx MXene nanosheet composite exhibited both good electrical conductivity (4.52 × 10-4 S/m) and favorable mechanical properties (tensile strength of 66.2 MPa and impact strength of 24.2 kJ/m2) when the content of Ti3C2Tx MXene nanosheets is 1.2 wt %. Thus, Ti3C2Tx MXene is a promising filler for electrically conductive adhesive with high electric conductivity and high mechanical performance.

Synthesis of porous carbon embedded with NiCo/CoNiO2 hybrids composites for excellent electromagnetic wave absorption performance.

A series of NiCo/CoNiO2@C hybrid composites were successfully prepared by a hydrothermal method and subsequent heat-treatment process. Porous carbon was synthesized through a fabric carbonization process derived from fish skin. The micro-morphology and minor component of NiCo/CoNiO2@C hybrid composites could be tuned by controlling the adjunction amount of Co2+ and Ni2+. The NiCo/CoNiO2@C hybrid composite exhibited strong electromagnetic wave absorption performance when the adjunction amount of Co2+ and Ni2+ was 0.4 mmol and 0.2 mmol. The optimal reflection loss could up to -74.3 dB at the matching thickness of 3.8 mm, while the corresponding widest effective absorption bandwidth (reflection loss values lower than -10 dB) is up to 6.32 GHz covering from 11.78 GHz to 18.0 GHz at the matching thickness of 2.4 mm. Based on the Maxwell-Garnet theory, the pore size of porous carbon materials could influence the dielectric constant which has a great effect on impedance. Previous work has illustrated that porous carbon carbonized at 650 °C processes the proper pore size for excellent impedance matching. Besides, NiCo alloy nanosphere and CoNiO2 nanoflower would provide magnetic loss and interface polarization for attenuating electromagnetic wave energy. Moreover, the conductive loss derived from porous carbon and dipolar loss which originated from the defects are also beneficial to decay electromagnetic energy. This work indicates that the as-prepared NiCo/CoNiO2@C hybrid composites accompanied with excellent electromagnetic wave absorption performance could act as a promising absorber to deal with the increasingly serious electromagnetic pollution.

Fabrication of NiFe2O4@carbon fiber coated with phytic acid-doped polyaniline composite and its application as an electromagnetic wave absorber.

In this work, a novel CF@NiFe2O4 composite coated with phytic acid-doped polyaniline (CF@NiFe2O4@p-PANI) was facilely synthesized. First, a typical solvothermal reaction was applied to obtain the CF@NiFe2O4 composite, and then the phytic acid-doped polyaniline was grown in situ on the surface of the CF@NiFe2O4 composite. The morphological structure, chemical composition, and surface functional group distribution of this hybrid were systematically evaluated. The magnetic saturation (M s) value of the hybrid is 29.9 emu g-1, which represents an improvement in the magnetic loss. According to its reflection loss curve, the hybrid exhibits a superior EM wave absorption capacity, with a minimum reflection loss value and effective absorbing bandwidth of -46 dB when the sample thickness is 2.9 mm, and an effective absorption bandwidth of 5 GHz when the sample thickness is 1.5 mm. The excellent performance of this hybrid can mainly be attributed to its ideal matching of magnetic loss and dielectric loss, interfacial polarizations, eddy current loss and interface relaxation. This new material has the potential to be a superior electromagnetic wave absorber or applied as a functional filler to modify resin matrices.

Hierarchical Fe3O4@carbon@MnO2 hybrid for electromagnetic wave absorber.

In this work, a novel Fe3O4@C@MnO2 hybrid was successfully synthesized via facile method. The morphology, structure, chemical composition, magnetic behavior and EM wave absorbing performance of the hybrid were systematically investigated. Results indicate that the hybrid possesses uniform hierarchical and mesoporous structure. The magnetic saturation(Ms) value of the hybrid is 19.8 emu g-1, which is beneficial to improve magnetic loss. According to its reflection loss curve, the hybrid performs superior EM wave absorption capacity, with a minimum reflection loss value and effective absorbing bandwidth of -35 dB and 5 GHz when the specimen thickness is 2.7 mm. The excellent performance of this hybrid can mainly be attributed to its ideal matching of magnetic loss and dielectric loss, large specific surface area, mesoporous structure and interfacial polarizations. Such new material has the potential to be a superior electromagnetic wave absorber, or applied as a functional filler to modify resin matrix.

A sandwich-like Si/SiC/nanographite sheet as a high performance anode for lithium-ion batteries.

Silicon/carbon (Si/C) nanocomposite anodes have attracted great interest for their use in lithium-ion batteries (LIBs). However, Si nanoparticles are difficult to stabilize on a carbon surface. Herein, we solve this stabilization problem by designing a Si/silicon carbide/nanographite sheet (Si/SiC/NanoG) nanocomposite. The Si/SiC/NanoG nanocomposite is synthesized by the magnesium thermal reduction of a mixture of silica (SiO2) nanoparticles and NanoG at low temperature, which results in a sandwich-like structure in which the middle SiC layer serves as a linker to stabilize the Si nanoparticles on the surface of NanoGs. Electrochemical characterization shows that the Si/SiC/NanoG nanocomposite anode exhibits outstanding electrochemical performance (an initial reversible capacity of 1135.4 mA h g-1 and 80.4% capacity retention after 100 cycles at 100 mA g-1). This high capacity retention is due to the strong connection between Si and NanoG through the interfacial SiC layer, which buffers the volume changes during the Li-Si alloying-dealloying process. This research will contribute to the design of advanced Si/C anode materials of LIBs.

Covalent Bonding of Si Nanoparticles on Graphite Nanosheets as Anodes for Lithium-Ion Batteries Using Diazonium Chemistry.

Silicon/carbon (Si/C) composite has been proven to be an effective method of enhancing the electrochemical performance of Si-based anodes for lithium-ion batteries (LIBs). However, the practical application of Si/C materials in LIBs is difficult because of the weak interaction between Si and C. In this study, we applied two-step diazotization reactions to modify graphite nanosheets (GNs) and Si nanoparticles (Si NPs), yielding a stable Si-Ar-GNs composite. Owing to aryl (Ar) group bonding, Si NPs were dispersed well on the GNs. The as-prepared Si-Ar-GNs composite delivered an initial reversible capacity of 1174.7 mAh·g-1 at a current density of 100 mAh·g-1. Moreover, capacity remained at 727.3 mAh·g-1 after 100 cycles, showing improved cycling performance. This synthesis strategy can be extended to prepare other Si/C anode materials of LIBs.

Enhancement of Cerenkov luminescence imaging by dual excitation of Er(3+),Yb(3+)-doped rare-earth microparticles.

UNLABELLED: Cerenkov luminescence imaging (CLI) has been successfully utilized in various fields of preclinical studies; however, CLI is challenging due to its weak luminescent intensity and insufficient penetration capability. Here, we report the design and synthesis of a type of rare-earth microparticles (REMPs), which can be dually excited by Cerenkov luminescence (CL) resulting from the decay of radionuclides to enhance CLI in terms of intensity and penetration. METHODS: Yb(3+)- and Er(3+)- codoped hexagonal NaYF4 hollow microtubes were synthesized via a hydrothermal route. The phase, morphology, and emission spectrum were confirmed for these REMPs by power X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectrophotometry, respectively. A commercial CCD camera equipped with a series of optical filters was employed to quantify the intensity and spectrum of CLI from radionuclides. The enhancement of penetration was investigated by imaging studies of nylon phantoms and nude mouse pseudotumor models. RESULTS: the REMPs could be dually excited by CL at the wavelengths of 520 and 980 nm, and the emission peaks overlaid at 660 nm. This strategy approximately doubled the overall detectable intensity of CLI and extended its maximum penetration in nylon phantoms from 5 to 15 mm. The penetration study in living animals yielded similar results. CONCLUSIONS: this study demonstrated that CL can dually excite REMPs and that the overlaid emissions in the range of 660 nm could significantly enhance the penetration and intensity of CL. The proposed enhanced CLI strategy may have promising applications in the future.