Logit-based exit choice model of evacuation in rooms with internal obstacles and multiple exits

A logit-based discrete choice model is proposed to study the exit choice behaviour of evacuees in rooms with internal obstacles and multiple exits. Several factors influencing the exit choice behaviour, including the information obtained by evacuees, the tendency of following others, the visibility and familiarity of exits and the physical conditions of nearby exits, are considered. Evacuees are allowed to re-select their target exits for minimizing the perceived disutility during evacuation process. Numerical results from applying the model to cellular automata simulation of evacuation are presented and the effects of some model parameters on evacuation time are investigated.     

时滞细胞神经网络概周期解的存在性与全局指数稳定性

通过利用Banach 空间中的不动点定理和Lyapunov泛函的方法,获得了时滞细胞神经网络概周期解的存在性与全局指数稳定性的新结论. 所获结果在较大程度上改进和推广了已有文献中的相应结果.     

动力系统的复杂性刻划

本文扼要地综述了近年来提出的刻划动力系统复杂性的各种度量．着重点在于将复杂性同随机性区分开．由此对于过去为刻划混沌而提出的度量,其中包括Ｌｙａｐｕｎｏｖ指数、拓扑熵、测度熵和Ｋｏｌｍｏｇｏｒｏｖ复杂性等,作了简单回顾．从自动机和信息论的观点对于包括ＡＣ、ＳＣ、ＥＭＣ在内的新提出的复杂性度量作了阐述．通过单峰映射和一维元胞自动机等例子对上述复杂性度量进行了比较,并较详细地介绍了利用形式语言和自动机来分析动力系统的方法．      

Construction of phase diagrams for nanoscaled Ising thin films on the honeycomb lattice using cellular automata simulation approach

The phase diagrams of the three-layer Ising model on the honeycomb lattice with a diluted surface have been constructed using the probabilistic cellular automata based on Glauber algorithm. The effects of the exchange interactions on the phase diagrams have been investigated. A general mathematical expression for the critical temperature is obtained in terms of relative coupling r = J₁/J and Δ_s = (J_s/J) ? 1, where J and J_s represent the nearest neighbor coupling within inner- and surface-layers, respectively, and each magnetic site in the surface-layer is coupled with the nearest neighbor site in the inner-layer via the exchange coupling J₁. In the case of antiferromagnetic coupling between surface-layer and inner-layer, system reveals many interesting phenomena, such as the possibility of existence of compensation line before the critical temperature.     

Discrete Lagrange problems with constraints valued in a Lie group

The Lagrange problem is established in the discrete field theory subject to constraints with values in a Lie group. For the admissible sections that satisfy a certain regularity condition, we prove that the critical sections of such problems are the solutions of a canonically unconstrained variational problem associated with the Lagrange problem (discrete Lagrange multiplier rule). This variational problem has a discrete Cartan 1-form, from which a Noether theory of symmetries and a multisymplectic form formula are established. The whole theory is applied to the Euler-Poincaré reduction in the discrete field theory, concluding as an illustration with the remarkable example of the harmonic maps of the discrete plane in the Lie group $SO(n)$.     

An Enzyme-Loaded Metal–Organic Framework-Assisted Microfluidic Platform Enables Single-Cell Metabolite Analysis

Colonization of cancer cells at secondary sites, a decisive step in tumor metastasis, is strongly dependent on the formation of metastatic microenvironments regulated by intrinsic single-cell metabolism traits. Herein, we report a single-cell microfluidic platform for high-throughput dynamic monitoring of tumor cell metabolites to evaluate tumor malignancy. This microfluidic device empowers efficient isolation of single cells (>99 %) in a squashed state similar to tumor extravasation, and employs enzyme-packaged metal–organic frameworks to catalyze tumor cell metabolites for visualization. The microfluidic evaluation was confirmed by in vivo assays, suggesting that the platform allowed predicting the tumorigenicity of captured tumor cells and screening metabolic inhibitors as anti-metastatic drugs. Furthermore, the platform efficiently detected various aggressive cancer cells in unprocessed whole blood samples with high sensitivity, showing potential for clinical application.     

Platinum(II)-Based Optical Probes for Imaging Quadruplex DNA Structures via Phosphorescence Lifetime Imaging Microscopy

G-quadruplex DNA is a non-canonical structure that forms in guanine-rich regions of the genome. There is increasing evidence showing that G-quadruplexes have important biological functions, and therefore molecular tools to visualise these structures are important. Herein we report on a series of new cyclometallated platinum(II) complexes which, upon binding to G-quadruplex DNA, display an increase in their phosphorescence, acting as switch-on probes. More importantly, upon binding to G-quadruplexes they display a selective and distinct lengthening of their emission lifetime. We show that this effect can be used to selectively visualise these structures in cells using Phosphorescence Lifetime Imaging Microscopy (PLIM).     

Autohydrolysis of Diglycine-Activated Succinic Esters Boosts Cellular Uptake

Rapid cellular uptake of synthetic molecules remains a challenge, and the motif frequently employed to generate prodrugs, succinic ester, unfortunately lowers the efficacy of the desired drugs due to their slow ester hydrolysis and low cell entry. Here we show that succinic ester-containing diglycine drastically boosts the cellular uptake of supramolecular assemblies or prodrugs. Specifically, autohydrolysis of the diglycine-activated succinic esters turns the nanofibers of the conjugates of succinic ester and self-assembling motif into nanoparticles for fast cellular uptake. The autohydrolysis of diglycine-activated succinic esters and drug conjugates also restores the efficacy of the drugs. 2D nuclear magnetic resonance (NMR) suggests that a “U-turn” of diglycine favors intramolecular hydrolysis of diglycine-activated succinic esters to promote autohydrolysis. As an example of rapid autohydrolysis of diglycine-activated succinic esters for instant cellular uptake, this work illustrates a nonenzymatic bond cleavage approach to develop effective therapeutics for intracellular targeting.     

Barrier-breaking effects of ultrasonic cavitation for drug delivery and biomarker release

Recently, emerging evidence has demonstrated that cavitation actually creates important bidirectional channels on biological barriers for both intratumoral drug delivery and extratumoral biomarker release. To promote the barrier-breaking effects of cavitation for both therapy and diagnosis, we first reviewed recent technical advances of ultrasound and its contrast agents (microbubbles, nanodroplets, and gas-stabilizing nanoparticles) and then reported the newly-revealed cavitation physical details. In particular, we summarized five types of cellular responses of cavitation in breaking the plasma membrane (membrane retraction, sonoporation, endocytosis/exocytosis, blebbing and apoptosis) and compared the vascular cavitation effects of three different types of ultrasound contrast agents in breaking the blood-tumor barrier and tumor microenvironment. Moreover, we highlighted the current achievements of the barrier-breaking effects of cavitation in mediating drug delivery and biomarker release. We emphasized that the precise induction of a specific cavitation effect for barrier-breaking was still challenged by the complex combination of multiple acoustic and non-acoustic cavitation parameters. Therefore, we provided the cutting-edge in-situ cavitation imaging and feedback control methods and suggested the development of an international cavitation quantification standard for the clinical guidance of cavitation-mediated barrier-breaking effects.     

Camellia sinensis: Insights on its molecular mechanisms of action towards nutraceutical,anticancer potential and other therapeutic applications

The Camellia sinensis plant provides a wide diversity of black, green, oolong, yellow, brick dark, and white tea. Tea is one of the majorly used beverages across the globe, succeeds only in the water for fitness and pleasure. Generally, green tea has been preferred more as compared to other teas due to its main constituent e.g. polyphenols which contribute to various health benefits. The aim of this updated and comprehensive review is to bring together the latest data on the phytochemistry and pharmacological properties of Camellia sinensis and to highlight the therapeutic prospects of the bioactive compounds in this plant so that the full medicinal potential of Camellia sinensis can be realised. A review of published studies on this topic was performed by searching PubMed/MedLine, Scopus, Google scholar, and Web of Science databases from 1999 to 2022. The results of the analysed studies showed that the main polyphenols of tea are the four prime flavonoids catechins: epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC), and epicatechin (EC) along with the beneficial biological properties of tea for a broad heterogeneity of disorders, including anticancer, neuroprotective, antibacterial, antiviral, antifungal, antiobesity, antidiabetes and antiglaucoma activities. Poor absorption and low bioavailability of bioactive compounds from Camellia sinensis are limiting aspects of their therapeutic use. More human clinical studies and approaching the latest nanoformulation techniques in nanoparticles to transport the target phytochemical compounds to increase therapeutic efficacy are needed in the future.