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[Display omitted] Supramolecular chirality systems have attracted tremendous research interest for their applications in wide fields. Pillar[ n ]arenes, as a young class of macrocyclic host, have been widely applied in assembly systems due to their excellent complexation ability. Notably, pillar[ n ]arenes has two stable conformers (p R and p S), whereas they exhibit a dynamically racemic equilibrium in solution due to fast interconversion by rotating the hydroquinone units along the annulus. Synthesizing stable and separable enantiomers remains a challenge for pillar[ n ]arenes. In this minireview, construction strategy of chiral pillar[ n ]arenes and their complexes was systematically summarized. Their applications in constructing circularly polarized luminescence materials were emphasized. This minireview could inspire more researchers to investigate chiral pillar[ n ]arenes with multifunctionality in future. [ABSTRACT FROM AUTHOR]

Carbon onions have shown potential applications in many fields due to their low density, tunable conductivity, excellent thermal and chemical stability. In this study, we report an efficient method for synthesis of gram-scale hollow carbon onions (HCNOs). A chemical vapor deposition (CVD) process was carried out at 700 °C with magnesium oxide supported cobalt as catalyst. Abundant HCNOs were obtained by leaching the CVD product in hydrochloric acid when the precursor weight ratio of cobalt and magnesium oxide is 5%. Scanning electron microscopy and transmission electron microscopy images indicate the sample is composed of hollow polyhedral particles with diameter of 10–50 nm. The thermogravimetric analysis indicates the purity of HCNOs is about 99%. X-ray diffraction and Raman spectra demonstrates a moderate graphitization of HCNOs in which graphite carbon and defective carbon both present. The graphite carbon can provide good conduction that is beneficial to introduce the microwave, while the defects can provide abundant polarization center to stimulate the formation of multiple dielectric resonances. The calculated reflection loss curve of HCNOs with a thin thickness of 2 mm exhibit wide absorption bandwidth at high frequency (13.5–16.9 GHz), indicating an excellent microwave absorption performance at high frequency. Image 10171 [ABSTRACT FROM AUTHOR]

[Display omitted] Dust pollution generated from metro construction can cause serious pneumoconiosis in workers. To efficiently relieve dust pollution in personnel breathing zones during drilling operations, this study applied a numerical simulation of a metro tunnel to analyze the effects of ventilation parameters (supply airflow volume and distance of forced air duct outlet from driving face) on the distribution behaviors of airflow velocity and dust concentrations. Sixteen ventilation conditions were designed to determine dust pollution characteristics in four personnel breathing zones, and optimal dimensionless ventilation parameters corresponding to efficient dust suppression performance were determined. The numerical simulation results indicated that each supply airflow volume corresponded to an optimal installation position of the forced air duct outlet. Without considering advancement of the driving face, the optimal dimensionless distance of the forced air duct outlet from the driving face (ratio of the distance of the forced air duct outlet from the driving face to the equivalent diameter of the excavated section) was 3.125 and 3.906 when the dimensionless supply airflow volume (ratio of supply airflow volume to the minimum supply airflow volume corresponding to the average section airflow velocity of 0.15 m/s) were 1.002–1.336 and 1.671–2.005, respectively. However, the recommended dimensionless distance of a forced air duct outlet from a driving face should not be 5.469 when the dimensionless supply airflow volume is 1.002–2.005. Considering a 5–10 m advancement of the driving face, the optimal dimensionless distance of the forced air duct outlet from the driving face was 3.125 when the dimensionless supply airflow volume was 1.002–2.005. The accuracy of the numerical simulation results was validated in field measurements. [ABSTRACT FROM AUTHOR]

In order to avoid the serious melt-dripping problems caused by conventional phosphorus flame retardants, a new arylene-ether containing monomer named 2,2′-(4,4′-(1,4-phenylenebis(oxy))bis(4,1-phenylene))bis(oxy) diethanol (PBPBD) was synthesized and introduced into the PET main-chain via condensation polymerization. With the incorporation of arylene-ether units, the thermal stability and the char residue from combustion of flame-retardant-element-free copolyesters containing PBPBD (BD x PETs) increased dramatically. However, the crystallinity and melting temperature of these copolymers were lower than the same quantities for PET. Thermal degradation kinetic was investigated using the Ozawa-Flynn-Wall method, which illustrated that the apparent activation energy for decomposition of the copolyesters was enhanced with increasing the conversion and the content of PBPBD. Py-GC/MS results showed that the PBBPD structural units undergo rearrangement reactions at high temperature, and ultimately form conjugated heteroaromatic structures, which lead to the formation of stable char residues with unique “stick-shaped” micro-morphology. Due to these rearrangement reactions, BD x PETs showed an expected flame retardant performance and a reduction in smoke generation during combustion. For example, the LOI value for BD 10 PET was 28.4, and the total smoke production (TSP) was 10.4 m 2 , much smaller than that for PET, 18.8 m 2 . Moreover, melt-dripping was restricted. [ABSTRACT FROM AUTHOR]

Bronchoscopic cryotherapy facilitates the treatment of endobronchial tuberculosis (EBTB) and helps suppress progressive bronchial stenosis. However, the molecular mechanism of bronchoscopic cryotherapy in EBTB patients has not been reported. Transcriptome sequencing was performed to explore differentially expressed mRNAs (DEGs) in EBTB patients before and after bronchoscopic cryotherapy. Gene Ontology (GO) and KEGG analyses were carried out. Five genes (MKLN1 , HIGD1A , PTGES , SKIL , and MCEMP1) were selected and validated using real-time qPCR (RT- qPCR). In transcriptome analysis, 448 DEGs with p < 0.05 and|logFC| > 1 were identified; of these, 171 and 277 DEGs were significantly up- and down-regulated after bronchoscopic cryotherapy, respectively. Results displayed 337 biological process (GO-BP), 48 cellular component (GO-CC) and 62 molecular function (GO-MF) terms and 20 KEGG pathways. RT- qPCR results were consistent with the sequencing data. These data provide informative evidence and recommendations for further scientific research on bronchoscopic cryotherapy for EBTB. • We firstly identified transcriptome map of EBTB patients before and after bronchoscopy cryotherapy treatment. • The results showed that 448 DEGs (171 upregulated and 277 downregulated) were obtained between BCT group and ACT group. • These results provide a theoretical basis for further exploring the molecular mechanism of bronchoscopy cryotherapy for EBTB. [ABSTRACT FROM AUTHOR]