We report a new class of ruthenium(II) polypyridine complexes functionalized with a nitrone group as phosphorogenic bioorthogonal probes. These complexes were very weakly emissive owing to rapid C=N ...isomerization of the nitrone moiety, but exhibited significant emission enhancement upon strain‐promoted alkyne–nitrone cycloaddition (SPANC) reaction with bicyclo6.1.0nonyne (BCN)‐modified substrates. The modification of nitrone with a dicationic ruthenium(II) polypyridine unit at the α‐C‐position and a phenyl ring at the N‐position led to remarkably accelerated reaction kinetics, which are substantially greater (up to ≈278 fold) than those of other acyclic nitrone–BCN systems. Interestingly, the complexes achieved specific cell membrane/cytosol staining upon specific labeling of an exogenous substrate, BCN‐modified decane (BCN‐C10), in live cells. Importantly, the in situ generation of the more lipophilic isoxazoline adduct in the cytoplasm resulted in increased cytotoxicity, highlighting a novel approach to apply the SPANC labeling technique in drug activation.
Reactivity and regioselectivity: Reactive phosphorogenic ruthenium(II) nitrone complexes were designed to label and visualize strained alkyne‐functionalized substrates in different cellular compartments (see scheme).
In this paper, an extended car-following model is proposed to simulate traffic flow by considering average headway of preceding vehicles group in intelligent transportation systems environment. The ...stability condition of this model is obtained by using the linear stability analysis. The phase diagram can be divided into three regions classified as the stable, the metastable and the unstable ones. The theoretical result shows that the average headway plays an important role in improving the stabilization of traffic system. The mKdV equation near the critical point is derived to describe the evolution properties of traffic density waves by applying the reductive perturbation method. Furthermore, through the simulation of space–time evolution of the vehicle headway, it is shown that the traffic jam can be suppressed efficiently with taking into account the average headway effect, and the analytical result is consistent with the simulation one.
•A new car-following model is proposed by considering the average headway effect of preceding vehicles group in ITS environment.•Linear analysis is carried out to study the stability of traffic flow.•The mKdV equation can be derived by using the reductive perturbation method to describe the density wave of traffic jam.•The results show that the average headway effect can efficiently suppressed the emergence of traffic jamming.
Balanced development is essential for sustainable development. Investigating the coordination between urban construction and district-level population density can deepen the knowledge of balanced ...development on the urban scale and promote better delivery of planning policy. This study took Shanghai as an example to explore the influence of three kinds of urban construction – market-driven urban construction, public transportation infrastructure and public service facilities – on district-level population density with longitudinal data (2003–2017). Nine variables were selected through a comprehensive review of the literature and the policy/planning practices of Shanghai. Structural equation modeling (SEM) and stepwise multivariate linear regression (SMLR) were integrated, forming an explorative SEM analysis framework to analyze the significance of the variables and their interplay. The results showed that market-driven urban construction had the most significant influence on district-level population density. However, it was not well integrated with public service facilities. Additionally, public service facilities and public transportation were not evenly distributed. Therefore, policies on improving the public transportation network and coordinating the three types of urban construction is imperative.
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•Balanced development at urban scale is important for sustainable society.•The study proposed an explorative structural equation modeling analysis framework.•Retail affects population density at highest level in urban fringe and suburban.•Metro affects population density through market-driven urban construction.•Public service facilities are not coordinating with the other urban construction.
Events are commonly used for raising people's interests in using urban space for social interaction. Although previous studies have paid much attention to mega events and civic events, events held by ...profit-making organizations such as shopping centers have not been examined yet. More importantly, at places with shortage in public spaces, the events being held in shopping centers may have the ability in helping community development. This study aims at categorizing and comparing the characteristics of different events in shopping centers of Hong Kong. Events data is collected from Facebook and manipulated under three criteria: duration, accessibility and community. The results show that events of shopping centers can realize community functions such as increased social interaction and strengthen social bonds to a certain degree. Also, they can benefit the community through different levels of community participation. Based on the findings, an extended POSPD scheme is considered to increase the public space in Hong Kong since shopping center is capable of accommodating civic events. Furthermore, the extended POSPD requires a cooperation of government, local community and shopping center developer, which will stimulate community development in the long run.
•The paper contributes to the literature of events by studying the community function of events in shopping centers.•The paper establishes three criteria for assessing the characteristics of events of shopping centers.•The paper proposed an extended POSPD to increase the public space that can held civic events.•The extended POSPD helps to tie up government, community and private development (shopping center) for community development.
With the rapid urbanization in cities around the world, new towns that are close to the existing urban fringe have been developed to accommodate the increasing population. However, due to the long ...development time of the infrastructure systems in these new towns, the establishment of public transportation services usually lags behind the population expansion. Therefore, to ensure urban accessibility, governments utilize bus networks to bridge the connectivity gaps of metro systems. To assist the design and decision-making required for bus and metro interconnectivity and optimize public transportation networks, this study proposed a quantitative network-based framework. The proposed framework extended the existing social network analysis theory and identified five indicators to assess and optimize the network design. To validate the proposed method, nine typical cases in Shanghai were examined. The results based on the proposed analysis framework suggest that more edges between access points (bus stops within the walkable area of a metro station entrance) and other nodes can improve the accessibility of the study area and create a well-integrated system. Therefore, this study is able to provide an insightful understanding of intermodal transportation coordination and transport facility arrangement.
•The study considers the integration of bus and mass transportation to improve the bus-to-metro accessibility of new town.•The study proposes a novelframework to evaluate and optimize the local bus network based on social network analysis.•The methodology developed in the study can generate links between bus stops with significant improvement of accessibility.
In this paper, an extended car-following model is proposed to simulate traffic flow by considering the honk effect. The stability condition of this model is obtained by using the linear stability ...analysis. The phase diagram shows that the honk effect plays an important role in improving the stabilization of traffic system. The mKdV equation near the critical point is derived to describe the evolution properties of traffic density waves by applying the reductive perturbation method. Furthermore, the numerical simulation is carried out to validate the analytical results and indicates that the traffic jam can be suppressed efficiently via taking into account the honk effect.
Based on an extended lattice hydrodynamic model considering the delay of the driver’s response in sensing headway, we get the time-dependent Ginzburg–Landau (for short, TDGL) equation to describe the ...transition and critical phenomenon in traffic flow by applying the reductive perturbation method. The corresponding solutions are obtained. Numerical simulation is carried out to examine the performance of the model and the results show coincidence with the analysis results.
The synthesis, characterization, photophysics, lipophilicity, and cellular properties of new phosphorescent ruthenium(II) polypyridine complexes functionalized with a dibenzocyclooctyne (DIBO) or ...amine moiety Ru(N^N)2(L)(PF6)2 are reported (L=4‐(13‐N‐(3,4:7,8‐dibenzocyclooctyne‐5‐oxycarbonyl) amino‐4,7,10‐trioxa‐tridecanyl‐aminocarbonyl‐oxy‐methyl)‐4′‐methyl‐2,2′‐bipyridine bpy‐DIBO, N^N=2,2′‐bipyridine bpy (1 a), 1,10‐phenanthroline phen (2 a); L=4‐(13‐amino‐4,7,10‐trioxa‐tridecanylaminocarbonyl‐oxy‐methyl)‐4′‐methyl‐2,2′‐bipyridine bpy‐NH2, N^N=bpy (1 b), phen (2 b)). The strain‐promoted alkyne–azide cycloaddition (SPAAC) reaction of the DIBO complexes 1 a and 2 a with benzyl azide were studied. Also, the DIBO complexes 1 a and 2 a can selectively label N‐azidoglycans located on the surface of CHO‐K1 and A549 cells that were pretreated with 1,3,4,6‐tetra‐O‐acetyl‐N‐azidoacetyl‐D‐mannosamine (Ac4ManNAz). Additionally, the intracellular trafficking and localization of these biomolecules were monitored using laser‐scanning confocal microscopy. Interestingly, the biolabeling and cellular uptake efficiency of the DIBO complexes 1 a and 2 a were cell‐line dependent, as revealed by flow cytometry and ICP‐MS. Furthermore, the complexes showed good biocompatibility toward the Ac4ManNAz‐pretreated cells in the dark, but exhibited photoinduced cytotoxicity due to the generation of singlet oxygen.
Tracing of cell‐surface glycans: New azide‐reactive phosphorescent ruthenium(II) polypyridine dibenzocyclooctyne (DIBO) complexes were designed to selectively label and visualize N‐azidoglycans of 1,3,4,6‐tetra‐O‐acetyl‐N‐azidoacetyl‐D‐mannosamine (Ac4ManNAz)‐pretreated cells (see figure).
The coordination of pyridyl-tetrazine to a cationic iridium(iii) center affords a novel class of luminogenic bioorthogonal probes for biomolecular labeling and cellular imaging.
In the Letter, a modified car-following model is presented, in which, the effects of vehicles (or non-motor vehicles) on other lanes without isolation belts are taken into account. The stability ...condition of the model is obtained by using the control theory method. To check the validity of the present theoretical scheme, the numerical simulation is carried out for the new car-following model, and the simulation result is consistent with the theoretical analysis.
► We propose a new car-following model considering the effects of the traffic vehicles (or non-motor vehicles) without isolation belts. ► The control theory method is introduced into car-following model. ► The numerical simulation is presented to confirm the theoretical results.
