In this work, poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium nanoparticles (NPs) supported on bamboo leaf-derived porous carbon (Ru/BC) has been synthesized via a one-step procedure. The ...structure and morphology of the as-synthesized samples were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). As a catalyst for hydrogen generation from the hydrolysis of ammonia-borane (AB, NH3BH3) at room temperature, Ru/BC stabilized with 1 mg of PVP exhibited high activity (TOF = 718 molH2·molRu−1·min−1) and low activation energy (Ea = 22.8 kJ mol−1). In addition, the catalyst could be easily recovered and showed fairly good recyclability with 55.6% of the initial catalytic activity retained after ten experimental cycles, which confirmed that PVP could stabilize the Ru NPs and prevent their agglomeration on BC surface. Our results suggest that PVP-stabilized Ru/BC is a highly efficient catalyst for the hydrolysis of AB.
•Ru nanoparticles are successfully supported on porous carbon (Ru/BC).•PVP-stabilized Ru/BC catalyst can efficiently catalyze AB hydrolysis.•Ru/BC-1 exhibits high activity with Ea of 22.8 kJ mol−1 and TOF of 718 molH2·molRu−1·min−1.•Ru/BC-1 can be easily recovered and exhibits fairly good recyclability.
This paper investigates the problems of passivity and passification for a class of nonlinear Markov jump genetic regulatory networks with time-varying delays and disturbances. By utilizing the ...Lyapunov–Krasovskii functional method, a novel delay-dependent passivity criterion is established in terms of linear matrix inequalities to guarantee the Markov jump genetic regulatory networks to be passive. Then, based on the obtained passivity conditions, the passification problem is further solved by designing a mode-dependent state feedback controller. A numerical example is presented to demonstrate the effectiveness and validity of the proposed approaches.
The low thermal conductivity and liquid-phase leakage of phase change materials seriously hinder their large-scale applications. Porous materials have been identified as an effective way to address ...the leakage and provide a thermally conductive network. Therefore, we designed an expanded graphite-based multifunctional composite phase change thermal storage materials for personal thermal management and antimicrobial in medical protection. Expanded graphite (EG) was used as the matrix, silver nanowires (Ag NWs) as the functional enhancement materials, and
n
-octadecane (OD) as the thermal storage materials. OD and Ag NWs were adsorbed in the porous structure of EG by vacuum-assisted impregnation. Finally, EG/Ag NWs/OD were combined with non-woven fabrics (N) by one-step hot pressing method to obtain EG/Ag NWs/OD-N composite with excellent comprehensive performance. With the mass ratio of EG to Ag NWs of 13:7, EG/Ag NWs/OD-N exhibited a thermal conductivity of 2.0130 W m
−1
K
−1
, which was improved by 1070.3% compared with pure OD. EG/Ag NWs/OD-N has a melting enthalpy of 137.85 J·g
−1
and a crystallization enthalpy of 128.97 J·g
−1
. In addition, EG/Ag NWs/OD-N display great antibacterial properties, thermal cycling stability, shape stability, and cycling persistence and showed excellent temperature control in protective clothing applications, offering great potential for large-scale applications.
Porous carbon derived from waste biomass has attracted great interest for supercapacitors due to high surface area, superior electrical conductivity, and excellent electrochemical properties. ...Moreover, it is of essential importance to control the microstructure for directing its application. Herein, nitrogen-doped porous carbon materials were synthesized from dried ginkgo leaves through alkali activation and the subsequent heating treatment, during which ureophil with high nitrogen content was used as additional nitrogen source. Ureophil not only obviously increases the nitrogen content of the sample, but also remarkably promotes the development of porous structure. Arising from the large specific surface area of 2947 m2 g−1 and high nitrogen content of 3.31 wt%, the as-prepared nitrogen-doped carbon achieves high specific capacitance (323.2 F g−1 at 0.5 A g−1) and superior rate capability (244 F g−1 at 20 A g−1). It also shows an outstanding cycling stability (0.00061% of capacitance decay per cycle for 12,000 cycles). The results demonstrate that our nitrogen-doped carbon derived from ginkgo leaves could be a potential candidate of electrode materials for practical applications in the fields of supercapacitor and other electrochemical energy storage and conversion devices.
Nitrogen-doped porous carbon materials were synthesized from dried ginkgo leaves, which exhibited high specific capacitance, superior rate capability and outstanding cycling stability. Display omitted
•Porous carbon materials were prepared from ginkgo leaves.•Nitrogen was doped into porous carbon using ureophil.•N-doped carbon has high specific capacitance (323 F g−1 at 0.5 A g−1) and superior rate capability (244 F g−1 at 20 A g−1).•Outstanding cycling stability (92.7% retention after 12,000 cycles at 10 A g−1) was achieved.
•The CF-UF coupled with HPLC-MS/MS method was developed and validated for unbound lenvatinib analysis.•Significant factors affecting CF-UF process was optimized.•Significant differences existed in ...the unbound fraction between individuals.•Please contact me if any possible requestion.
In clinical practice, the determination of unbound drug concentration is very important for dose adjustment and toxicity prediction because only the unbound fraction can achieve a pharmacological effect. A fast, sensitive and accurate analytical method of centrifugal ultrafiltration coupled with high performance liquid chromatography-tandem mass spectrometry method was developed and applied to allow the quantification of unbound lenvatinib concentration. The application of linear regression analysis was used to examine the effects of centrifugal force, centrifugal time, and protein content on ultrafiltrate volume (Vu). The results indicated that the centrifugal force and centrifugal time have an influence on Vu that is significantly positive (P < 0.05). This developed method with good linearity (r2 = 0.9996), good accuracy (bias % ≤ 2.24 %), good precision (CV % ≤ 7.10 %), and good recovery (95.46 %−106.46 %) was suitable for routine clinical practice and studies. Particularly, the ultrafiltration membrane had no non-specific binding to lenvatinib. The unbound fractions can be separated in just 15 min. This method was applied to quantify clinical samples and to determine the plasma protein binding and unbound fraction of lenvatinib. This study provides a more effective and promising method for determination of unbound lenvatinib. It could be beneficial to measure the unbound concentration of lenvatinib in personalized medicine and therapeutic drug monitoring in routine clinical practice.
This paper is concerned with the finite-time H∞ control problem for a class of uncertain switched linear neutral systems with time-varying delays. By fully exploiting the mode-dependency of the ...proposed Lyapunov–Krasovskii functionals, the considered systems could be further investigated with stable and unstable subsystems being concurrently contained. Sufficient criteria are first derived for ensuring finite-time boundedness of the underlying system with a given maximum ratio of activation time between unstable subsystems and stable ones. Then the H∞ performance analysis and the memory state-feedback controller design are carried out for a given performance index. Finally, two numerical examples are presented to illustrate the potential and advantages of the developed findings.
The transcription factor CONSTANS (CO) integrates day‐length information to induce the expression of florigen FLOWERING LOCUS T (FT) in Arabidopsis. We recently reported that the C‐terminal CCT ...domain of CO forms a complex with NUCLEAR FACTOR‐YB/YC to recognize multiple cis‐elements in the FT promoter, and the N‐terminal tandem B‐box domains form a homomultimeric assembly. However, the mechanism and biological function of CO multimerization remained unclear. Here, we report that CO takes on a head‐to‐tail oligomeric configuration via its B‐boxes to mediate FT activation in long days. The crystal structure of B‐boxesCO reveals a closely connected tandem B‐box fold forming a continuous head‐to‐tail assembly through unique CDHH zinc fingers. Mutating the key residues involved in CO oligomerization resulted in a non‐functional CO, as evidenced by the inability to rescue co mutants. By contrast, a transgene encoding a human p53‐derived tetrameric peptide in place of the B‐boxesCO rescued co mutant, emphasizing the essential role of B‐boxesCO‐mediated oligomerization. Furthermore, we found that the four TGTG‐bearing cis‐elements in FT proximal promoter are required for FT activation in long days. Our results suggest that CO forms a multimer to bind to the four TGTG motifs in the FT promoter to mediate FT activation.
Examination of the crystal structure of Nterminal tandem B‐box domains of CONSTANS (CO), the key player in photoperiod flowering pathway, reveals that B‐Boxes of CO form a head‐to‐tail type linear oligomer, which mediates the multimeric assembly of CO to enhance the accurate targeting of CO to FLOWERING LOCUS T.
We aimed to investigate the effect of Cyclocarya paliurus leaves extracts (CP) on glucose and blood lipid metabolism and its relationship with intestinal flora in type 2 diabetes mellitus (T2DM) ...patients.
In this open-label, 84-day randomized controlled trial, a total of 38 T2DM patients were randomly assigned to the CP group or the Glipizide group (G group) in a 2:1 ratio. T2DM-associated metabolic phenotypes, gut microbiota and metabolites including short-chain fatty acids (SCFAs) and bile acids (BAs) were detected.
At the end of intervention, CP, like Glipizide, significantly improved HbA1c level and other glucose metabolism parameters (fasting plasma glucose (FBG), 2-hour post-meal blood glucose (2hPBG), the area under curve of oral glucose tolerance test glucose (OGTT glucose AUC)). Moreover, CP also resulted in the significant improvement in the levels of blood lipid and blood pressure. Notably, the improvement in blood lipid(triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c)) and blood pressure (diastolic blood pressure (DBP)) was significantly greater in the CP group compared with the G group. Furthermore, the liver and kidney function parameters did not significantly change in both CP group and the G group over the 84-day period. Additionally, the enrichment of potentially beneficial bacteria (Faecalibacterium and Akkermansia), SCFAs and unconjugated BAs and the depletion of potential pathogenic bacteria (Prevotella_9) and conjugated BAs were observed in the CP group, while the abundances of the gut microbial were kept stable in the G group after intervention.
CP displays a more beneficial effect in the alleviation of T2DM-associated metabolic phenotypes than glipizide by regulating gut microbiota and metabolites in T2DM patients, with no significant effects on liver and kidney function.
•3D nanocubic NiCoS-PBA is fabricated with six concave faces and numerous micropores.•The etching step in the preparation process is the key, which produces more active sites for sulfidation to ...enhance the electrochemical properties.•The specific capacitance of NiCoS-PBA reaches 965 C g−1 at 1 A g−1.
In this work, 3D nanocubes NiCo-PBA sulfide (NiCoS-PBA) has been prepared by ammonia solution etching and vulcanizing for NiCo-Prussian blue analogue (NiCo-PBA) homemade. The SEM and TEM show that the obtained NiCoS-PBA has the 3D nanocubes structure with rough surface and inward depressions. Electrochemical analysis indicates that an ultrahigh specific capacitance of NiCoS-PBA is 965 C g−1 at 1 A g−1, which is better than that of NiCo-PBA# (256 C g−1), only sulfurized NiCoS-PBA# (369 C g−1) and only etched NiCo-PBA (281 C g−1) at the same condition. This is thanks to the 3D nanocubes structure, which has large accessible areas and rich active sites for redox reactions to enhance the electrochemical performance of supercapacitors. Meanwhile, this also illustrates that the etching and vulcanizing treatments can significantly boost the specific capacitance of NiCoS-PBA. Additionally, the NiCoS-PBA-based asymmetric supercapacitor (ACS) device offers an energy density of 61.7 Wh kg−1 at a power density of 800.1 W kg−1. It is believed that NiCoS-PBA will be a strong contender as an electrode material in supercapacitors.
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Without effective and secure hydrogen production, it is impossible to utilize hydrogen energy on a large scale. Whereas hydrogen emission from NaBH4 hydrolysis with high hydrogen yield is an ...impressively efficient hydrogen supply method. However, it is affected by sluggish hydrogen production kinetics and low yields, therefore it is required to develop hydrolysis catalysts with good performance under alkaline conditions. In this study, a composite of unique CoNi layered double hydroxide (CoNi-LDH) nanosheets interconnected by muti-walled carbon nanotubes (MWCNTs) was prepared for the first time, and the surface was modified with metal borides produced by in-situ reduction. Among them, CoNi-LDH nanosheets are created when CoNi-MOF spontaneously derivates in alkaline electrolytes. The successful preparation of CoB-LDH-CNT has been confirmed by SEM, TEM, EDS, XRD, and XPS characterization. The hydrolysis experiments show that it has good catalytic activity with an optimal hydrogen generation rate (HGR) of 5167.72 mL·min−1·g−1 and low activation energy (Ea) of 29.93 kJ·mol−1. After ten cycles of experiments, it still has 75.4% of the initial performance, showing excellent stability, which may be attributed to the fact that MWCNTs can help to reconnect broken nanosheets during the reaction. This interconnected multistage structure offers a new methodology for enhancing the catalytic performance of metal boride and metal hydroxide materials.
•Novel CoB-LDH-CNT compositions was prepared for hydrogen production of NaBH4 hydrolysis for the first time.•CoB-LDH-CNT-50 achieves good HER performance and the lowest Ea of 29.93 kJ∙mol−1.•The bonding effect of multi-walled carbon nanotubes (MWCNTs) enabled the catalyst to maintain 75.4% activity after 10 cycles.
