Oxygen carriers are attracting extensive interest in biomedical research and clinical applications such as wound healing, alternative blood transfusion, and acute trauma treatment. Great efforts have ...been devoted to the generation of oxygen carriers with special functions and properties to meet specific demands. Here, we present black phosphorus (BP)-loaded separable responsive microneedles (MNs) with oxygen carrying and controllable oxygen delivering ability for wound healing. Such MNs are composed of a polyvinyl acetate (PVA) backing layer and gelatin methacryloyl (GelMA) tips that are loaded with BP quantum dots (BP QDs) and hemoglobin (Hb). Taking advantage of the fast dissolvability of PVA, the backing layer soon disappears after the MNs are applied to skin and the noncytotoxic, biocompatible GelMA tips are left inside the skin. Due to the excellent photothermal effect of BP QDs and the reversible oxygen binding property of Hb, the local temperature of the skin will increase after near-infrared ray irradiation, resulting in the responsive oxygen release. Notably, the practical performance of such MNs has been demonstrated by treating the full-thickness cutaneous wounds of a type I diabetes rat model, indicating their potential value in wound healing and other related biomedical fields.
Silicon (Si) is considered to be a promising next-generation anode material for lithium-ion batteries. However, the large volume change during (de)lithiation processes causes fracture of Si ...electrodes, thereby limiting Si’s practical application in lithium-ion batteries. In this work, we formulate a variational-based fully chemo-mechanical coupled computational framework to study diffusion induced large plastic deformation and phase field fracture in Si electrodes. Into this framework we incorporate a recently developed reaction-controlled diffusion model to predict two-phase lithiation for amorphous Si (a-Si) and crystalline Si (c-Si) as well as diffusion induced anisotropic deformation for c-Si. The variational formulation suggests to consider the deformation field, the chemical potential, and the damage field as primary unknowns. The concentration field is considered as a local variable and is recovered from the chemical potential on the element level. We carry out several numerical simulations to show the performance of our computational model and point out the significance of accurately accounting for the presence of the reaction front when modeling diffusion induced fracture problems for both a-Si and c-Si electrodes. In addition, we investigate how the fracture energy release rate, electrode geometry, and geometrical constraints affect the fracture behavior of Si electrodes.
•A variational based computational framework that combines multiple dissipative phenomena is proposed.•Diffusion induced large plastic deformation and phase field fracture during two-phase lithiation of silicon electrodes is modeled.•The effect of fracture energy release rate, electrode geometry, and geometric constraints on the fracture behavior of silicon electrodes is investigated.
The use of nighttime lights (NTL) data to proxy for local economic activity is well established in remote sensing and other disciplines. Validation studies comparing NTL data with traditional ...economic indicators, such as Gross Domestic Product (GDP), underpin this usage in applied studies. Yet the most widely cited validation studies do not use the latest NTL data products, may not distinguish between time-series and cross-sectional uses of NTL data, and usually are for aggregated units, such as nation-states or the first sub-national level, yet applied studies increasingly focus on smaller and lower-level spatial units. To provide more updated and disaggregated validation results, this study examines relationships between GDP and NTL data for 2657 county-level units in China, observed each year from 2012 to 2019. The NTL data used were from three sources: the Defense Meteorological Satellite Program (DMSP), whose time series was recently extended to 2019; and two sets of Visible Infrared Imaging Radiometer Suite (VIIRS) data products. The first set of VIIRS products is the recently released version 2 (V.2 VNL) annual composites, and the second is the NASA Black Marble annual composites. Contrasts were made between cross-sectional predictions for GDP differences between areas and time-series predictions of economic activity changes over time, and also considered different levels of spatial aggregation.
A patch with the capability of avoiding wound infection and promoting tissue remolding is of great value for wound healing. In this paper, we develop a biomass chitosan microneedle array (CSMNA) ...patch integrated with smart responsive drug delivery for promoting wound healing. Chitosan possesses many outstanding features such as the natural antibacterial property and has been widely utilized for wound healing. Besides, the microstructure of microneedles enables the effective delivery of loaded drugs into the target area and avoids the excessive adhesion between the skin and the patch. Also, vascular endothelial growth factor (VEGF) is encapsulated in the micropores of CSMNA by temperature sensitive hydrogel. Therefore, the smart release of the drugs can be controllably realized via the temperature rising induced by the inflammation response at the site of wounds. It is demonstrated that the biomass CSMNA patch can promote inflammatory inhibition, collagen deposition, angiogenesis, and tissue regeneration during the wound closure. Thus, this versatile CSMNA patch is potentially valuable for wound healing in clinical applications.
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•An antibacterial and angiogenic chitosan patch with microneedle array.•Biomass antibacterial chitosan preventing bacterial infection.•Microstructure of microneedle improve the ability of drug delivery.•Temperature responsive hydrogel encapsulating for intelligent drug release.•Microneedle array patch promoting wound healing.
In this paper, a cooperative search method for multiple UAVs is proposed to solve the problem of low efficiency of multi-UAV task execution by using a cooperative game with incomplete information. To ...improve search efficiency, CBBA (Consensus-Based Bundle Algorithm) is applied to designate the tasks area for each UAV. Then, Independent Deep Reinforcement Learning (IDRL) is used to solve Nash equilibrium to improve UAVs’ collaborations. The proposed reward function is smartly developed to guide UAVs to fly along the path with higher reward value while avoiding the collisions between UAVs during flights. Finally, extensive experiments are carried out to compare our proposed method with other algorithms. Simulation results show that the proposed method can obtain more rewards in the same period of time as other algorithms.
Tsunami is one of the most destructive natural disasters and the probabilistic tsunami hazard assessment (PTHA) has become increasingly popular in both academic and engineering field. However, most ...methods to carry out PTHA cannot avoid large number of scenario simulations generated by comprehensive assessment of the uncertainties of all seismic parameters. In order to balance the accuracy and feasibility in PTHA, we propose a more efficient approach. Based on the linear assumption of tsunami waves in deep water, the computation of tsunami wave propagation is given by the linear superposition of waves caused by unit sources of water level disturbance, which transforms a large number of seismic tsunami scenarios simulations into a limited number of simulations on wave propagating from each unit source. By placing 5,438 unit sources in Gaussian-shaped waveform with the interval of 0.1° around Manila Trench to approximate the initial water level disturbance under any combination of seismic parameters, we have evaluated 1,380,000 potential seismic scenarios in the Manila trench area. The water level fluctuation process of each target point along 100 m isobaths in every scenario is calculated to estimate whether the maximum wave height of the leading wave exceeds a specific critical value. Combining the probability density of each seismic parameter, the exceedance probabilities of specific wave heights and hazard curves at all target points are given.
•An efficient approach to execute probabilistic tsunami hazard assessment is introduced.•1,380,000 potential seismic scenarios have been computed.•Tsunami hazard curves along 100 m isobaths of Hainan Island are presented.
Apigenin is a non-toxic natural flavonoid that is abundantly present in common fruits and vegetables. It has been reported that apigenin has various beneficial health effects such as ...anti-inflammation and chemoprevention. Multiple studies have shown that inflammation is an important risk factor for atherosclerosis, diabetes, sepsis, various liver diseases, and other metabolic diseases. Although it has been long realized that apigenin has anti-inflammatory activities, the underlying functional mechanisms are still not fully understood.
In the present study, we examined the effect of apigenin on LPS-induced inflammatory response and further elucidated the potential underlying mechanisms in human THP-1-induced macrophages and mouse J774A.1 macrophages. By using the PrimePCR array, we were able to identify the major target genes regulated by apigenin in LPS-mediated immune response. The results indicated that apigenin significantly inhibited LPS-induced production of pro-inflammatory cytokines, such as IL-6, IL-1β, and TNF-α through modulating multiple intracellular signaling pathways in macrophages. Apigenin inhibited LPS-induced IL-1β production by inhibiting caspase-1 activation through the disruption of the NLRP3 inflammasome assembly. Apigenin also prevented LPS-induced IL-6 and IL-1β production by reducing the mRNA stability via inhibiting ERK1/2 activation. In addition, apigenin significantly inhibited TNF-α and IL-1β-induced activation of NF-κB.
Apigenin Inhibits LPS-induced Inflammatory Response through multiple mechanisms in macrophages. These results provided important scientific evidences for the potential application of apigenin as a therapeutic agent for inflammatory diseases.
Purpose
COVID-19 has severely affected urban and rural tourism in China, which has been extensively reported in the newspapers. This paper aims to discuss the impact of COVID-19 on urban and rural ...tourism at each critical juncture of the COVID-19 pandemic, as well as the studies, measures and attitudes of various stakeholders toward urban and rural tourism and their future development.
Design/methodology/approach
This paper collects Chinese news reports as the research object and uses ROST Content Mining 6.0 and Gephi software to analyze and visualize the data for high-frequency words and analyzed the discourse of stakeholders within the newspaper text.
Findings
This study found that prior to February 20, 2020, the Chinese Government mainly focused on pandemic prevention. From February 21 to April 3 (before The Qingming Festival), resumption of work and production became the theme. From April 4 to May 1 (before May Day), a time-sharing reservation system was widely implemented and the differentiation between urban and rural tourism became more prominent. After May 1, rural tourism attracted greater attention.
Originality/value
This paper uses discourse analysis to understand the impact of COVID-19 on urban and rural tourism from the perspective of time nodes and the relationship between various stakeholders and predicts the development trends within urban and rural tourism. This paper enriches and expands tourism management knowledge in the face of major crises, providing valuable advice for managers and investors and makes suggestions for the development of urban and rural tourism.
COVID-19下中国的城乡旅游：恢复措施与旅游发展研究
目的
COVID-19已严重影响了中国的城市和乡村旅游业, 报纸上对此进行了广泛报道。本文旨在探讨在COVID-19大流行的每个关键时刻对城乡旅游的影响, 以及各种利益相关者对城乡旅游及其未来发展的观点, 措施和态度。
设计/方法
本文以中文新闻报道为研究对象, 利用ROST Content Mining 6.0和Gephi软件对高频词数据进行分析和可视化, 分析了报纸正文中利益相关者的话语。
结果
这项研究发现, 在2020年2月20日之前, 中国政府主要将重点放在疫情防控上。 2月21日至4月3日（清明节之前）, 复工复产成为主题。 从4月4日至5月1日（五一节之前）, 分时预约系统得到广泛实施, 城市和乡村旅游业的区别更加突出。 5月1日之后, 乡村旅游引起了更多关注。
创意/价值
本文通过话语分析从时间节点和各个利益相关者之间的关系的角度了解了COVID-19对城乡旅游业的影响, 并预测了城乡旅游业的发展趋势。 面对重大危机, 本文丰富和扩展了旅游管理知识, 为管理者和投资者提供了宝贵的建议, 并为城乡旅游业的发展提供了建议。
Turismo urbano y rural bajo COVID-19 en China Investigación sobre medidas de recuperación y desarrollo turístico
Propósito
COVID-19 ha afectado gravemente al turismo urbano y rural en China, que ha sido ampliamente informado en los periódicos. Este documento tiene como objetivo discutir el impacto de COVID-19 en el turismo urbano y rural en cada coyuntura crítica de la pandemia de COVID-19, así como los puntos de vista, las medidas y las actitudes de diversos interesados en relación con el turismo urbano y rural y su desarrollo futuro.
Diseño/metodología/enfoque
Este documento recopiló informes de noticias chinos como objeto de investigación y utilizó el software ROST Content Mining 6.0 y Gephi para analizar y visualizar los datos de palabras de alta frecuencia y analizó el discurso de los interesados dentro del texto del periódico.
Conclusiones
Este estudio encontró que antes del 20 de febrero de 2020, el gobierno chino se centró principalmente en la prevención de la pandemia en lugares pintorescos. Del 21 de febrero al 3 de abril (antes del Festival de Qingming), la reanudación del trabajo y la producción se convirtió en el tema. Desde el 4 de abril hasta el 1 de mayo (antes del Primero de Mayo), se implementó ampliamente un sistema de reserva de tiempo compartido y la diferenciación entre el turismo urbano y el rural se hizo más prominente. Después del 1 de mayo, el turismo rural atrajo mayor atención.
Originalidad/valor
En este documento, se utiliza el análisis del discurso para comprender el impacto de COVID-19 en el turismo urbano y rural desde la perspectiva de los nodos de tiempo y la relación entre los diversos interesados y se predice las tendencias de desarrollo dentro del turismo urbano y rural. Este trabajo enriquece y amplía el conocimiento de la gestión turística frente a las grandes crisis, brindando valiosos consejos a administradores e inversores, y hace sugerencias para el desarrollo del turismo urbano y rural.
Microneedles have attracted increasing interest among various medical fields due to their painless, noninvasive, and efficient way of drug delivery. However, practical applications of these ...microneedles in different epidermal locations and environments are still restricted by their low adhesion and poor antimicrobial activity. Here, inspired by the antibacterial strategy of
and adhesion mechanisms of mussel byssi and octopus tentacles, we develop hierarchical microneedles with multifunctional adhesive and antibacterial abilities. With polydopamine hydrogel as the microneedle base and a loop of suction-cup-structured concave chambers encircling each microneedle, the generated microneedles can fit the skin well; keep strong adhesion in dry, moist, and wet environments; and realize self-repair after being split into two parts. Besides, as polymyxin is loaded into both the hydrogel tips and the polydopamine base, the microneedles are endowed with excellent ability to resist common bacteria during storage and usage. We have demonstrated that these microneedles not only showed excellent adhesion when applied to knuckles and ideal antibacterial activity but also performed well in drug-sustained release and treatment for the osteoarthritis rat model. These results indicate that bioinspired multifunctional microneedles will break through the limitation of traditional methods and be ideal candidates for versatile transdermal drug delivery systems.
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