4,9- and 4,10-Substituted pyrenes: synthesis, successful isolation, and optoelectronic properties.

We report herein a way to prepare and purify optoelectronic functional 4,9- and 4,10-substituted pyrene isomers. By tuning the size of substituents, the designed 4,9- and 4,10-isomers can be successfully isolated by recycling preparative size-exclusion chromatography (SEC) and/or repeated recrystallization. The structure and purity of the isolated compounds 1-5 have been confirmed by 1H NMR, 13C NMR, and HRMS. The photophysical and electrochemical properties of compounds 1-5 have been studied in detail both experimentally and theoretically. The lowest transitions of these pyrenes, 1-5, are allowed, with moderate to high fluorescence quantum yields and radiative decay rates around 108 s-1. The differences between the electrochemical and photophysical properties of 4,9-, 4,10-, 1,6-, and 2,7-substituted isomers are compared and concluded.

Combined Spectroscopic and TD-DFT Analysis to Elucidate Substituent and Acidochromic Effects in Organic Dyes: A Case Study on Amino- versus Nitro-Substituted 2,4-Diphenylquinolines.

A combined spectroscopic and TD-DFT case study was performed, to identify a robust method to calculate the complex near UV/Vis absorption spectra of various amino- vs. nitro-substituted 2,4-diphenylquinolines, which vary strongly under neutral and successively acidic conditions. For this, different DFT functionals were tested for geometry optimization and the TD part to calculate the neutral and different protonated species in a fast screening approach, i. e. using single point calculations in an implicit solvent. Offset-corrected M06HF, hitherto only applied to polymers, was identified as a suitable method to reproduce the absorption spectra in a reasonable fashion for all different substitution pattern and all different protonated species at different pH values; moreover, the method properly predicts the energetic ordering of low-lying n-π* and ππ* transitions, which is decisive for the non-/emissive nature of the different compounds. In all, this might provide a valuable tool for computer-aided design of related classes of compounds.

Excited-state non-radiative decay in stilbenoid compounds: an ab initio quantum-chemistry study on size and substituent effects.

In the framework of optoelectronic luminescent materials, non-radiative decay mechanisms are relevant to interpret efficiency losses. These radiationless processes are herein studied theoretically for a series of stilbenoid derivatives, including distyrylbenzene (DSB) and cyano-substituted distyrylbenzene (DCS) molecules in vacuo. Given the difficulties of excited-state reaction path determinations, a simplified computational strategy is defined based on the exploration of the potential energy surfaces (PES) along the elongation, twisting, and pyramidalization of the vinyl bonds. For such exploration, density functional theory (DFT), time-dependent (TD)DFT, and complete-active-space self-consistent field/complete-active-space second-order perturbation theory (CASSCF/CASPT2) are combined. The strategy is firstly benchmarked for ethene, styrene, and stilbene; next it is applied to DSB and representative DCS molecules. Two energy descriptors are derived from the approximated PES, the Franck-Condon energy and the energy gap at the elongated, twisted, and pyramidalized structures. These energy descriptors correlate fairly well with the non-radiative decay rates, which validates our computational strategy. Ultimately, this strategy may be applied to predict the luminescence behavior in related compounds.

Excited state absorption spectra of dissolved and aggregated distyrylbenzene: A TD-DFT state and vibronic analysis.

A time-dependent density functional theory study is performed to reveal the excited state absorption (ESA) features of distyrylbenzene (DSB), a prototype π-conjugated organic oligomer. Starting with a didactic insight to ESA based on simple molecular orbital and configuration considerations, the performance of various density functional theory functionals is tested to reveal the full vibronic ESA features of DSB at short and long probe delay times.

Highly efficient expression of functional recombinant human keratinocyte growth factor 1 and its protective effects on hepatocytes.

Three forms of recombinant human keratinocyte growth factor 1 (rhKGF1) with or without the native signal peptide or a 23-amino acid truncation were expressed in Spodoptera frugiperda 9 (Sf9) cells by designing with insect codon usage. Immunoblotting demonstrated that these rhKGF1 proteins were recognized by a human anti-KGF1 antibody. The multiplicity of infection and timing of harvest had a significant effect on protein yield, protein quality, and cytotoxicity. Our results indicated that the native signal peptide directed KGF1 secretion from insect cells, reaching a maximum at 60 h postinfection. Although secretion of rhKGF1194 was less efficient than that of rhKGF1163 and rhKGF1140, protein secretion is an attractive pathway for simple purification of biologically active rhKGF1 at a high yield. Moreover, the sizes of rhKGF1194 and rhKGF1163 were similar (20 kDa), suggesting that the signal peptide may be recognized and removed in Sf9 cells. A 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay was used to analyze the biological function of rhKGF1, indicating that the three forms of rhKGF1 had a similar mitogenic function in BaF3 cells. Furthermore, to elucidate the effect of rhKGF1 on cytoprotection of liver cells, we used KGF1 pretreatment of an acute liver injury model. The results indicated that rhKGF1 prevented necrosis and apoptosis of CCl4-treated HL7702 cells in vitro and in vivo. These results suggest that KGF1 may be a candidate therapeutic drug for acute liver injury.

Optically induced charge-transfer in donor-acceptor-substituted p- and m- C2B10H12 carboranes.

Icosahedral carboranes, C2B10H12, have long been considered to be aromatic but the extent of conjugation between these clusters and their substituents is still being debated. m- and p-Carboranes are compared with m- and p-phenylenes as conjugated bridges in optical functional chromophores with a donor and an acceptor as substituents here. The absorption and fluorescence data for both carboranes from experimental techniques (including femtosecond transient absorption, time-resolved fluorescence and broadband fluorescence upconversion) show that the absorption and emission processes involve strong intramolecular charge transfer between the donor and acceptor substituents via the carborane cluster. From quantum chemical calculations on these carborane systems, the charge transfer process depends on the relative torsional angles of the donor and acceptor groups where an overlap between the two frontier orbitals exists in the bridging carborane cluster.

Sequential-Stimuli Induced Stepwise-Response of Pyridylpyrenes.

Stimuli-responsive materials, especially multi-stimuli-responsive materials, can sense external stimuli such as light, heat, and force, have shown great potential in drug delivery, data storage, encryption, energy-harvesting, and artificial intelligence. Conventional multi-stimuli-responsive materials are sensitive to each independent stimulus, causing losses in the diversity and accuracy of the identification for practical application. Herein, a unique phenomenon of sequential-stimuli induced stepwise-response generated from elaborately designed single-component organic materials is reported, which shows large bathochromic shifts up to 5800 cm-1 under sequential stimuli of force and light. In contrast to multi-stimuli-responsive materials, the response of these materials strictly relies on the sequence of stimuli, allowing logicality, rigidity, and accuracy to be integrated into one single-component material. The molecular keypad lock is built based on these materials, pointing promising to a future for this logical response in significant practical applications. This breakthrough gives a new drive to classical stimuli-responsiveness and provides a fundamental design strategy for new generations of high-performance stimuli-responsive materials.

SLC7A11, a potential immunotherapeutic target in lung adenocarcinoma.

SLC7A11 has significant translational value in cancer treatment. However, there are few studies on whether SLC7A11 affects the immune status of lung adenocarcinoma (LUAD). Information on SLC7A11 expression and its impact on prognosis was obtained from the cancer genome atlas and gene expression omnibus databases. The differentially expressed genes (DEGs) were analysed by GO and KEGG. GSEA enrichment analysis was performed in the SLC7A11-high and SLC7A11-low groups. The relationship between SLC7A11 and tumour immunity, immune checkpoints, and immune cell infiltration was studied using R language. We analysed the correlation between SLC7A11 and chemotactic factors (CFs) and chemokine receptors using the TISIDB database. SLC7A11 is overexpressed in many tumours, including LUAD. The 5-year overall survival of patients in the SLC7A11-high group was lower than in the SLC7A11-low group. KEGG analysis found that the DEGs were enriched in ferroptosis signaling pathways. GSEA analysis found that the survival-related signaling pathways were enriched in the SLC7A11-low group. The SLC7A11-low group had higher immune scores and immune checkpoint expression. SLC7A11 was negatively correlated with many immune cells (CD8+ T cells, immature dendritic cells), CFs, chemokine receptors (such as CCL17/19/22/23, CXCL9/10/11/14, CCR4/6, CX3CR1, CXCR3) and MHCs (major histocompatibility complex). SLC7A11 may regulate tumour immunity and could be a potential therapeutic target for LUAD.

Travel time prediction of urban public transportation based on detection of single routes.

Improving travel time prediction for public transit effectively enhances service reliability, optimizes travel structure, and alleviates traffic problems. Its greater time-variance and uncertainty make predictions for short travel times (≤35min) more subject to be influenced by random factors. It requires higher precision and is more complicated than long-term predictions. Effectively extracting and mining real-time, accurate, reliable, and low-cost multi-source data such as GPS, AFC, and IC can provide data support for travel time prediction. Kalman filter model has high accuracy in one-step prediction and can be used to calculate a large amount of data. This paper adopts the Kalman filter as a travel time prediction model for a single bus based on single-line detection: including the travel time prediction model of route (RTM) and the stop dwell time prediction model (DTM); the evaluation criteria and indexes of the models are given. The error analysis of the prediction results is carried out based on AVL data by case study. Results show that under the precondition of multi-source data, the public transportation prediction model can meet the accuracy requirement for travel time prediction and the prediction effect of the whole route is superior to that of the route segment between stops.

The intelligent engine start-stop trigger system based on the actual road running status.

With the rapid development of urbanization and the popularization of the vehicle, the frequent occurrence of traffic jams results in idling fuel waste, environmental pollution, and other issues. In order to alleviate these problems, engine start-stop technology has been widely used in different types of vehicles in recent years. However, current start-stop trigger technology has many deficiencies, such as mistaken triggering and frequent engine start-stop, which greatly reduces user driving experience, causing most of them to deactivate this system. The intelligent engine start-stop trigger (IEST) system based on the actual road running status was established by building the image recognition model and the digital traffic analysis model in order to solve this problem. A system test shows that IEST can avoid frequently engine starting and stopping. The results show that IEST could effectively improve the driving experience and reduce engine fuel consumption, and it promotes conventional engine start-stop technology.

Diethylamine fluorescence sensor based on silica hollow sphere photonic crystals.

In this study, based on silica hollow sphere photonic crystals (SHSPCs), a simple and selective fluorescence sensor for high-performance diethylamine detection was developed. The sensor does not involve complicated integration of arrays or tedious synthetic work. During the detection, the SHSPCs could significantly enhance the fluorescence intensity of rhodamine 6G (Rh6G), and meanwhile, adsorb some Rh6G on their surface. Due to the competitive adsorption, diethylamine could free the Rh6G which was adsorbed on the surface of the SHSPCs, thus enhancing the fluorescence emission intensity with the increase of Rh6G concentration. The second enhancement of the fluorescence emission enabled the selective detection of diethylamine. It is remarkable that a simple and readily available dye (Rh6G) facilitates the efficient detection of diethylamine. Moreover, the sensor has good interference immunity, stability and reusability.

Research on the method of travel area clustering of urban public transport based on Sage-Husa adaptive filter and improved DBSCAN algorithm.

The travel trajectory data of mobile intelligent terminal users are characterized by clutter, incompleteness, noise, fuzzy randomness. The accuracy of original data is an essential prerequisite for better results of trajectory data mining. The Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is one of the most effective trajectory data mining methods, but the selection of input parameters often limits it. The Sage-Husa adaptive filtering algorithm effectively controls the error range of mobile phone GPS data, which can meet the positioning accuracy requirements for DBSCAN spatial clustering having the advantages of low cost and convenient use. Then, a novel cluster validity index was proposed based on the internal and external duty cycle to balance the influence of the distance within-cluster, the distance between clusters, and the number of coordinate points in the process of clustering. The index can automatically choose input parameters of density clustering, and the effective clustering can be formed on different data sets. The optimized clustering method can be applied to the in-depth analysis and mining of traveler behavior trajectories. Experiments show that the Sage -Husa adaptive filtering algorithm proposed further improves the positioning accuracy of GPS, which is 17.34% and 15.24% higher eastward and northward, 14.25%, and 18.17% higher in 2D and 3D dimensions, respectively. The number of noise points is significantly reduced. At the same time, compared with the traditional validity index, the evaluation index based on the duty cycle proposed can optimize the input parameters and obtain better clustering results of traveler location information.

The Central Role of Nitrogen Atoms in a Zeolitic Imidazolate Framework-Derived Catalyst for Cathodic Hydrogen Evolution.

Platinum usually offers the most effective active center for hydrogen evolution reaction (HER), because of the optimal trade-off between the adsorption and desorption of hydrogeN atoms (H*) on Pt atoms. Herein, we report an unusual result regarding the active center of a HER catalyst, which was synthesized by electrodepositing traces of Pt nanoparticles (NPs) into a porous nitrogen-rich dodecahedron matrix derived from zeolitic imidazolate framework ZIF-8. With an ultra-low Pt loading of 2.76 µg cm-2 , the N-Pt-bonded catalyst can produce a current density of 117 mA cm-2 for the HER in 1.0 m H2 SO4 at an overpotential of 50 mV, whereas the commercial Pt/C (300 µg cm-2 Pt) can only reach 50 mA cm-2 under the same conditions. Cyclic voltammetry demonstrates that both the H* adsorption and the Pt oxidation are not allowed to occur on this catalyst, due to a full surface coverage of the trace Pt NPs by imidazole. The results from the specially designed experiments indicate that the imidazole N atoms may act as proton anchor-sites for the HER due to their electron donor nature. Density functional theory calculations also support a catalytic HER mechanism centered at the Pt-supported N active center, which needs a Gibbs free energy of H* absorption (ΔGH* ) significantly smaller than the absolute value of ΔGH* on the Pt(111) surface. We hope that the results of this study will encourage the research on novel N-centered catalysts for the HER.

2,7-Carbazole Derived Organoboron Compounds: Synthesis and Molecular Fluorescence.

Triarylboranes have drawn much attention in OLEDs owing to their remarkable solid-state luminescence properties. Here two new A-D-A type compounds, 2,7-bis(dimesitylboryl)-N-ethyl-carbazole (BCz) using triarylborane as electron acceptor and carbazole as electron donor while 2,7-bis((4-(dimesitylboryl)phenyl)ethynyl)-9-ethyl-carbazole (BPACz) using phenylacetylene as extra conjugated bridge, have been synthesized and their photoluminescence related properties in various states have been investigated both experimentally and theoretically. Both compounds show blue emission with high quantum yields, being potential candidates for blue OLED materials.

Air-Stable Organic Radicals: New-Generation Materials for Flexible Electronics?

In the last few years, air-stable organic radicals and radical polymers have attracted tremendous attention due to their outstanding performance in flexible electronic devices, including transistors, batteries, light-emitting diodes, thermoelectric and photothermal conversion devices, and among many others. The main issue of radicals from laboratory studies to real-world applications is that the number of known air-stable radicals is very limited, and the radicals that have been used as materials are even less. Here, the known and newly developed air-stable organic radicals are summarized, generalizing the way of observing air-stable radicals. The special electric and photophysical properties of organic radicals and radical polymers are interpreted, which give radicals a wide scope for various of potential applications. Finally, the exciting applications of radicals that have been achieved in flexible electronic devices are summarized. The aim herein is to highlight the recent achievements in radicals in chemistry, materials science, and flexible electronics, and further bridge the gap between these three disciplines.

Evaluation of passenger satisfaction of urban multi-mode public transport.

The scientific evaluation of passenger satisfaction for public transport is helpful to enhance the attraction of public transport. To improve the accuracy of passenger satisfaction evaluation for public transport and the scientificity and objectivity of the index weighting, combining the characteristics of analytic hierarchy process (AHP), entropy weight method (EWM) and fuzzy comprehensive evaluation(FCE) method, the passenger satisfaction evaluation system for Ningbo's urban public transportation was built. The paper analyzed 5046 questionnaires on conventional bus transit and 1682 questionnaires on rail transit in Ningbo city, Passenger satisfaction for Ningbo city's public transport was evaluated comprehensively, and the evaluation results showed that the overall passenger satisfaction of the public transport in Ningbo was 91.2 in 2019, The case study shows that the application of the AHP-EWM-FCE model on the multi-mode public transport system can objectively quantify passengers' feelings about urban public transport service, and thus provide a theoretical basis for the improvement of passenger satisfaction in Ningbo.

[The effect of matrine on the signal transduction pathway of transforming growth factor-beta1 in human lung fibroblast cells].

OBJECTIVE: To investigate the effect of matrine on the signal transduction pathway of transforming growth factor-beta1 (TGF-beta1). METHODS: The effect of TGF-beta1, Staurosporine, PD98059 and matrine on the expression of CTGF, CTGF mRNA, p-Smad2, and p-ERK1/2 were evaluated by Western blot in cultured HLF-02 cells. Immunohistochemical staining was applied to test the expression of CTGF and the expression level of CTGF mRNA was assayed by RT-PCR. RESULTS: Basal levels of CTGF protein were observed in cultured HLF-02. The expression of CTGF, CTGF mRNA, p-Smad2 and p-ERK1/2, in HLF-02 cells were stimulated significantly (P < 0.01) by 1 ng/mL TGF-beta1 treatment. The increase of CTGF protein was inhibited significantly by pre-incubation with Staurosporine (SP) and PD98059 (P < 0.01). And matrine could markedly inhibited the up-regulation of CTGF, CTGF mRNA, p-Smad2 and p-ERK1/2 (P < 0.05 or P < 0.01) in a concentration-dependant manner. CONCLUSION: CTGF, CTGF mRNA, p-Smad2 and p-ERK1/2 of HLF-02 cells could be significantly up-regulated after treated with TGF-beta1, and these increases could be inhibited significantly by matrine. This implied that matrine inhibit the expression of CTGF and CTGF mRNA induced by TGF-beta1 through the Smad2 and ERK signal transduction pathways.

[The effect or rosiglitazone on signal pathways of transforming growth factor-beta1 in human lung fibroblast].

OBJECTIVE: To investigate the expression of CTGF, CTGF mRNA, NF-kappaB and AP-1 induced by TGF-beta1 in human lung fibroblast (HLF-02), and study the effect and possible mechanism of rosiglitazone on signal pathways of TGF-beta1 in HLF-02. METHODS: The effects of TGF-beta1, curcumin, PDTC and rosiglitazone on the expression of CTGF, NF-kappaB and AP-1 were evaluated with Western blot. The expression of CTGF was also detected with immunohistochemistry assay. The level of CTGF mRNA was detected with RT-PCR. RESULTS: (1) The CTGF protein levels of HLF-02 cells were significantly up-regulated after incubated with 1 ng/mL TGF-beta1 for 15 min (P<0.01 vs Control). The CTGF mRNA was also up-regulated. The levels of CTGF protein and CTGF mRNA expression was up-regulated by TGF-beta1 in a time-dependent manner. (2) The expression of NF-kappaB and AP-1 increased after HLF-02 cells were incubated with 1 ng/mL TGF-beta1 for 30 min (P<0.01 vs Control). The CTGF protein levels were inhibited obviously after HLF-02 cells were incubated with PDTC or curcumin. (3) The expression of CTGF, NF-kappaB and AP-1 decreased after pre-incubation with different doses of rosiglitazone (P<0.01 vs TGF-beta1 group). The CTGF mRNA were also markedly inhibited (P<0.01 vs TGF-beta1 group). CONCLUSION: It is supposed that rosiglitazone inhibits CTGF expression induced by TGF-beta1 in HLF-02 cells by activating PPARgamma through NF-kappaB and AP-1 signal transduction pathways.

Modeling vehicle interior noise exposure dose on freeways: Considering weaving segment designs and engine operation.

Vehicle interior noise functions at the dominant frequencies of 500 Hz below and around 800 Hz, which fall into the bands that may impair hearing. Recent studies demonstrated that freeway commuters are chronically exposed to vehicle interior noise, bearing the risk of hearing impairment. The interior noise evaluation process is mostly conducted in a laboratory environment. The test results and the developed noise models may underestimate or ignore the noise effects from dynamic traffic and road conditions and configuration. However, the interior noise is highly associated with vehicle maneuvering. The vehicle maneuvering on a freeway weaving segment is more complex because of its nature of conflicting areas. This research is intended to explore the risk of the interior noise exposure on freeway weaving segments for freeway commuters and to improve the interior noise estimation by constructing a decision tree learning-based noise exposure dose (NED) model, considering weaving segment designs and engine operation. On-road driving tests were conducted on 12 subjects on State Highway 288 in Houston, Texas. On-board Diagnosis (OBD) II, a smartphone-based roughness app, and a digital sound meter were used to collect vehicle maneuvering and engine information, International Roughness Index, and interior noise levels, respectively. Eleven variables were obtainable from the driving tests, including the length and type of a weaving segment, serving as predictors. The importance of the predictors was estimated by their out-of-bag-permuted predictor delta errors. The hazardous exposure level of the interior noise on weaving segments was quantified to hazard quotient, NED, and daily noise exposure level, respectively. Results showed that the risk of hearing impairment on freeway is acceptable; the interior noise level is the most sensitive to the pavement roughness and is subject to freeway configuration and traffic conditions. The constructed NED model shows high predictive power (R = 0.93, normalized root-mean-square error [NRMSE] < 6.7%). IMPLICATIONS: Vehicle interior noise is usually ignored in the public, and its modeling and evaluation are generally conducted in a laboratory environment, regardless of the interior noise effects from dynamic traffic, road conditions, and road configuration. This study quantified the interior exposure dose on freeway weaving segments, which provides freeway commuters with a sense of interior noise exposure risk. In addition, a bagged decision tree-based interior noise exposure dose model was constructed, considering vehicle maneuvering, vehicle engine operational information, pavement roughness, and weaving segment configuration. The constructed model could significantly improve the interior noise estimation for road engineers and vehicle manufactures.

A new cellular automaton model for urban two-way road networks.

A new cellular automaton (CA) model is proposed to simulate traffic dynamics in urban two-way road network systems. The NaSch rule is adopted to represent vehicle movements on road sections. Two novel rules are proposed to move the vehicles in intersection areas, and an additional rule is developed to avoid the "gridlock" phenomenon. Simulation results show that the network fundamental diagram is very similar to that of road traffic flow. We found that the randomization probability and the maximum vehicle speed have significant impact on network traffic mobility for free-flow state. Their effect may be weak when the network is congested.