To get the safe and effective therapy for liver cancer, multifunctional nanoparticulate systems with therapeutic efficacy for biomedical application are progressing quite rapidly. The aim of the ...present research is to determine the potential of doxorubicin (DOX)-loaded folic acid-polyethylene glycol-β-cyclodextrin (FA-PEG-β-CD) nanoparticles (NPs) as drug-delivery system for liver cancer therapy. The targeting delivery of FA-PEG-β-CD was synthesized from FA and β-CD with PEG as a linker, which then loaded antitumor drug DOX to get the FA-PEG-β-CD/DOX NPs. The physicochemical characterizations including flourier transform infrared,
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H nuclear magnetic resonance, transmission electron microscope and dynamic light scattering, drug-loading content, drug encapsulation efficiency, blood compatibility, and in-vitro drug release were investigated. Finally, the in-vitro antitumor activity was estimated by HepG2 cells. The size of FA-PEG-β-CD NPs was about 20-80 nm, while FA-PEG-β-CD/DOX NPs was 30-60 nm. And the FA-PEG-β-CD/DOX NPs have drug-loading efficiency (11.9%) and encapsulation efficiency (95.2%). The in-vitro drug release results showed that the FA-PEG-β-CD NPs could not merely improve the solubility of hydrophobic drugs but also control the drug release. Blood compatibility assays revealed that DOX-loaded NPs did not induce blood hemolysis. In summary, the drug delivery of FA-PEG-β-CD NPs is suitable to carry the drug to the tumor tissues and release the drug effectively, and FA-PEG-β-CD/DOX NPs may be a potential platform for improving the treatment of liver cancer.
Te-vacancy-rich CoTe2−x nanoparticles confined in hollow hierarchical gridded structured CoTe2−x@3DPSNDC composite has been synthesized to cope with the non-negligible dissolution and shuttle effects ...of K-polytellurides. Benefiting from the synergistic regulation of the robust chemisorption and physical confinement of S, N-codoped dual-type carbon-confinement structure, and defect chemistry acceleration reaction kinetics, the CoTe2−x@3DPSNDC electrode exhibits ultra-stable cycling stability and rapid potassium storage performance.
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•3D hierarchical grid structured dual-type carbon-confined Te-vacancy-rich CoTe2−x nanodots (CoTe2−x@3DPSNDC) were synthesized.•The nature behind the evolution and the capacity decay of CoTe2 was clarified.•3DPSNDC effectively suppresses the dissolution and shuttle of potassium polytellurides (K-pTex) through physical confinement and chemisorption.•Te-vacancy-rich CoTe2−x significantly accelerates the K-ion diffusion kinetics.•The CoTe2−x@3DPSNDC electrode manifest excellent potassium storage performance.
Metal tellurides (MTes) have emerged as highly promising anode materials for potassium-ion batteries (PIBs) due to their exceptional volumetric capacity and superior electronic conductivity. The practical application of MTes, however, faces challenges such as slow kinetics, volumetric effects, and ill-defined shuttling phenomena of K-polytellurides (K-pTex). Herein, we present a groundbreaking solution through the development of Te-vacancy-rich CoTe2−x nanoparticles confined within a 3D honeycomb-like, hollow hierarchical gridded porous structured, S, N co-doped dual-carbon structural composite (CoTe2−x@3DPSNDC) via facile defect chemistry. This well-designed composite offers an unparalleled combination of fast ion/electron transport and stable K-pTex, propelling battery reactions to new heights. State-of-the-art in-/ex-situ techniques and density functional theory calculations reveal the evolution and shuttling mechanism of K-pTex. Remarkably, our study validates the exceptional physical confinement and chemisorption capabilities of S, N co-doped dual-type carbon skeletons on K5Te3 and K2Te3, leading to ultra-stable potassium-ion storage. Furthermore, the Te vacancies substantially boost the intrinsic conductivity of CoTe2−x, resulting in accelerated reaction kinetics and enhanced rate performance of the CoTe2−x@3DPSNDC electrode which achieved an impressive capacity of 508.1 mAh cm−3 at 5.0 A g−1. Our advanced design concept provides unique insights into the construction of MTes anodes for achieving stable cyclability and fast-charging PIBs.
•Optimal designs of Tradable Credit Scheme (TCS) with asymmetric transaction cost.•Pareto-improving and financial feasibility conditions are derived.•Extended results for heterogeneous commuters.•The ...significant impact of the asymmetry in transaction cost is unveiled.
Tradable credit schemes (TCS) have been promoted as an alternative to congestion pricing in recent years. Most existing TCS studies assume a frictionless trading market that incurs zero transaction cost. In this study, we propose to examine how transaction cost, taking the form of brokerage fee charged by a TCS operator for the deal-matching service, impacts the performance of TCS in the context of morning commute. Unlike the existing studies, the brokerage fee is assumed to be proportional to the transaction value and asymmetrically split between buyers and sellers. Using the bottleneck model, the optimal TCS design is first obtained for the case of homogeneous commuters and asymmetric transaction cost. We also derive the conditions that ensure Pareto-improving for commuters and financial self-sufficiency for the operator. The latter means the brokerage fee can cover the operator’s cost. These analytical results are then extended to cases considering user heterogeneity—which allows commuters to have different values of times (VOT) and desired arrival times at the workplace—and coarse charging design. Among other things, we find that an asymmetric fee structure is better for system performance when buyers bear a higher share of the transaction cost.
Demand Responsive Connectors (DRCs) have become a more general-purpose flexible transit service that caters to patrons' personal needs. The traditional DRC operation, however, suffers from low ...efficiency due to excessive detours and incurs diseconomies of scale with respect to the demand and service area. To tackle this issue, we propose a novel DRC fed by shared bikes, which functions as an access/egress mode for certain request points. Analytical models are derived for the joint design of such a hybrid system. A mixed-integer non-linear programme is established to minimise the total system cost. A heuristic solution algorithm is developed by combining the simulated annealing and branch-and-bound algorithms. A series of numerical cases are designed to evaluate the proposed system's performance against the traditional ones. The results demonstrate that the introduction of shared bikes can reduce the DRC tour length and consequently save total system costs.
Cerium dioxide (CeO2) semiconductor has received wide attention in the field of energy and environment due to its excellent oxygen storage capacity and abundant oxygen vacancies (OVs). Previous ...research demonstrated that the morphology and structure of the crystal had great influence on the physicochemical properties of the material. Herein, CeO2 nanomaterials with different morphologies were prepared via a facile hydrothermal and template method. Systematic material characterizations suggested that the synthetic CeO2 has different morphologies with CeO2 nanorods (NRs), nanocubes (NCs), nanosheets (NSs), hollow spheres (HSs), and mesoporous CeO2 (m-CeO2), respectively. The visible-light-induced degradation performance of CeO2 with different morphologies was investigated in aqueous solution using the antibiotic tetracycline (TC) as a model pollutant. The experimental results exhibited that the CeO2NRs possessed the best adsorption capacity and photocatalytic activity and more than 89.35% TC could be removed within 90 min. Combined with the XPS characterization results implied that the concentrations of Ce3+ and OVs on the surface of CeO2 with different morphologies were discrepancy, and the improved photocatalytic performance of CeO2NRs was mainly due to the higher concentration of Ce3+ and OVs on the catalyst surface. These results confirmed that the regulation of the morphology of CeO2 could effectively enhance its photocatalytic activity. Furthermore, the results of active species trapping experiments proved that the super oxide anion (•O2-) radical and hole (h+) played dominant roles in the degradation of TC.
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•In all morphologies, CeO2NRs exhibited a satisfactory TC degradation performance under visible light irradiation.•During photocatalysis, Ce3+ and OVs are essential for the photocatalytic properties of CeO2.•Notably, adsorption plays the same important role as photocatalysis in TC removal.
A pomegranate-like SnSe/ZnSe@C anode has been rationally designed and fabricated via electrostatic spraying and high-temperature selenization, exhibiting fast and ultrastable sodium storage ...capability.
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Tin selenide (SnSe) is considered as a potential anode for sodium-ion batteries (SIBs) owing to its high theoretical specific capacity. Unfortunately, it suffers from drastic volume expansion/contraction during sodium ions insertion/extraction, resulting in poor cycling stability. Herein, a pomegranate-inspired porous carbon shell wrapped heterogeneous SnSe/ZnSe composite (SnSe/ZnSe@C) is exquisitely designed and fabricated through electrostatic spraying followed by high-temperature selenization. The polyacrylonitrile-derived carbon shell acts as an adhesive to link the porous cubic SnSe/ZnSe and form highly interconnected microcircuits to improve the electron/ion transfer efficiency and inhibit the bulk volume change of internal metallic selenide nanoparticles and polyselenides dissolution during repeated cycling. Moreover, the abundant heterostructure interface of SnSe/ZnSe further significantly accelerates the electrons/ions transport. As a result, the as-prepared SnSe/ZnSe@C electrode exhibits a high specific capacity (508.3 mAh g−1 at 0.05 A g−1), excellent rate performance (177.8 mAh g−1 at 10.0 A g−1), and remarkable cycling stability (195.9 mAh g−1 after 10,000 cycles at 5.0 A g−1). Furthermore, in-situ X-ray diffraction (XRD)/Raman, ex-situ transmission electron microscopy, and kinetic analysis clearly reveal a four-step electrochemical reaction process and battery-capacitor dual-mode sodium storage mechanism. This work provides a new perspective for developing commercial SIBs anode materials with high capacity and long lifespan.
As a major part of public transportation systems, bus transit has been regarded as an effective mode to alleviate traffic congestion and solve vehicle emission problems. The performance of a bus ...transit system depends largely on the design of bus stop locations. This research proposes a multi-period continuum model (peak and off-peak hours) to optimize the design of a bus route for four different vehicle types (i.e., supercharge bus, compressed natural gas (CNG) bus, lithium-ion battery bus, and diesel bus) considering driving regimes and pollutant cost. Inter-stop driving regimes—acceleration, cruising, coasting, and deceleration—are explicitly introduced into the optimization to determine whether and how the coasting regime should be undertaken in the tradeoff between commercial speed of vehicles and operating costs. The cost effectiveness of each alternative has been investigated in a life cycle and compared with respect to different vehicle types. The method has been applied to the real-world bus route no. 7 in Yaan City (China). The results of numerical experiments show that through optimization the total system cost can be reduced by more than 50%. The results of the continuum model are validated by comparison with the discretized results, and the outcomes are similar (with error less than 3%). Finally the life-cycle cost of the four vehicle types is analyzed, and the results indicate that, because of high purchase prices, it is difficult for clean-energy buses to outperform conventional buses in a life cycle (normally eight years), unless subsidies are provided.
In recent years the metropolitans in China have seen the surging installations of the left-turn waiting area (LWA) at the signalized intersections. The design allows the left-turning vehicles to ...enter the intersection at the onset of the through green phase (of the same approach) and wait for the exclusive left-turn signal at the LWA. The LWA layout can effectively reduce the probability of stranded and queue overflow of the left-turn vehicles, but no study is conducted yet to assess the safety performance of the signalized intersections with LWA. The paper adopts the traffic conflict technique (represented by post-encroachment time), compares the discrepancy of conflict types between intersections with LWA and without, and develops the severity models to identify the contributing factors for the left-turn conflicts. Results demonstrate that the left-turn volume, driving outside the LWA, running red light, the presence of secondary conflicts, and the rear-end conflicts significantly increase the severities of traffic conflicts at the LWA. The findings serve to provide recommendations to revise the current design standard of the LWA (GB5768-2009) and consequently improve the safety operations of signalized intersections with LWA in China.
Sodium-ion batteries have great potential to become large-scale energy storage devices due to their abundant and low-cost resources. However, the lack of anode and cathode materials with both high ...energy density and long-term cycling performance significantly affects their commercial applications. In this work, uniform CoTe
nanoparticles are generated from the tellurization of Co nanoparticles, which were coated with polyvinylpyrrolidone in a three-dimensional (3D) porous carbon matrix (CoTe
@3DPNC). Finally, a dual-type carbon confinement structure is formed after tellurization during which citric acid is adopted as the source of the inner carbon scaffold. The hierarchical carbon matrix not only builds a robust and fast ion/electronic conductive 3D architecture but also mitigates the volume expansion and aggregation of CoTe
during sodium insertion/extraction. Remarkably, the CoTe
@3DPNC electrode displays a high reversible capacity (216.5 mAh g
/627.9 mAh cm
at 0.2 A g
after 200 cycles) and outstanding long-term cycling performance (118.1 mAh g
/342.5 mAh cm
even at 5.0 A g
after 2500 cycles). Kinetics tests and capacitance calculations clearly reveal a battery-capacitive dual-model Na-storage mechanism. Furthermore,
XRD/SEM/TEM demonstrate superior stability during sodium insertion/extraction. This work provides a valuable strategy for the rational structural design of long-life electrodes for advanced rechargeable batteries.
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