Low Band Gap Polymers Based on Isodiketopyrrolopyrroles, Aminobenzodiones, 1,8-Benzodifuranones and Naphthodiones

In this work new monomers and polymers with donor-acceptor ability and polymers containing diketopyrrolo[3,2-b]pyrrole (isoDPP), benzodione and naphthodione chromophores in the main chain with deep colour, broad absorption and low band gap are prepared and investigated. The compounds might be suitable for electronic applications, especially in solar cell devices. Characteristic properties are studied using spectroscopic methods (UV/vis, fluorescecne, NMR spectroscopy), gel permeation chromatography, cyclic voltammetry, elemental analysis, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Using Stille coupling, conjugated polymers containing isoDPP were prepared. The polymers exhibit a strong bathochromic shift compared with the previously reported isoDPP polymers and also show a high glass transition temperature (Tg) and excellent thermal stability. Photoirradiation studies indicate that the polymers in solution are extremely stable against UV and visible light irradiation. Spectroelectrochemical studies indicated a reversible electrochromism with isosbestic points near 710 nm. Using Pd-atalysed Buchwald amination, some polymers based on aminobenzodiones were prepared and characterized. The polymers exhibit quite low band gaps (1.07 to 1.18 eV), high photostabilty and a large solvatochromic shift up to 3140 cm–1. Furthermore, the polymers show broad UV/vis absorption bands in a range from 400 to 900 nm with high extinction coefficients of 1.7 to 3.1*104 L mol–1 cm–1. Furthermore, four new monomers and two polymers based on naphthodifuranone (NDF) were synthesized. These compounds exhibit broad UV/vis absorption bands. Apart from that, for the first time monomers and polymers based on naphthodipyrrolidone (NDP) were synthesized in this work. The NDP-based polymers not only exhibit broad UV/vis absorption with high extinction coefficients, but also possess low band gaps. The broad absorption in the visible, combined with high colour depth and low band gap render NDP-based polymers interesting as building blocks for optoelectronic materials, especially for solar cell applications

Assessment of Reclamation Treatments of Abandoned Farmland in an Arid Region of China

Reclamation of abandoned farmland is crucial to a sustainable agriculture in arid regions. This study aims to evaluate the impact of different reclamation treatments on abandoned salinized farmland. We investigated four artificial reclamation treatments, continuous cotton (CC), continuous alfalfa (CA), tree-wheat intercropping (TW) and trees (TS), which were conducted in 2011–2012 in the Manasi River Basin of Xinjiang Province, China. Soil nutrient, microorganism and enzyme activity were examined in comparison with natural succession (CK) in an integrated analysis on soil fertility improvement and soil salinization control with these reclamations. Results indicate that the four artificial reclamation treatments are more effective approaches than natural restoration to reclaim abandoned farmland. TW and CA significantly increased soil nutrient content compared to CK. CC reduced soil salinity to the lowest level among all treatments. TW significantly enhanced soil enzyme activity. All four artificial reclamations increased soil microbial populations and soil microbial biomass carbon. TW and CA had the greatest overall optimal effects among the four treatments in terms of the ecological outcomes. If both economic benefits and ecological effects are considered, TW would be the best reclamation mode. The findings from this study will assist in selecting a feasible method for reclamation of abandoned farmland for sustainable agriculture in arid regions.This research was supported by the Special Fund for Agro-scientific Research in the Public Interest (201503120); Science and Technology Research and Achievement Transformation Project of The Xinjiang Production and Construction Crops (2016AD022); and the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2014BAC14B03)

Next-Generation Composite Coating System: Nanocoating

Nanocoating combines the protective properties of conventional coating system with effects on nanoscale such as high hardness, UV scattering, and uniform dispersing. Their facile and low-cost synthesis, together with superior protective properties and multi-functionalities, makes nanocoating attractive candidates for next-generation coating systems. In this review, a brief introduction regarding mainstream nanocoating and its related challenges including the zinc oxide-, titanium dioxide-, silica dioxide-, graphene-, carbon nanotube-based nanocoating system is presented. Finally, a perspective of the nanocoating is demonstrated

Cardioprotective effects of tanshinone IIA pretreatment via kinin B2 receptor-Akt-GSK-3β dependent pathway in experimental diabetic cardiomyopathy

<p>Abstract</p> <p>Aims</p> <p>Diabetic cardiomyopathy, characterized by myocardial structural and functional changes, is a specific cardiomyopathy develops in patients with diabetes mellitus. The present study was to investigate the role of kinin B2 receptor-Akt-glycogen synthase kinase (GSK)-3β signalling pathway in mediating the protective effects of tanshinone IIA (TSN) on diabetic cardiomyopathy.</p> <p>Methods and results</p> <p>Streptozocin (STZ) induced diabetic rats (n = 60) were randomized to receive TSN, TSN plus HOE140 (a kinin B2 receptor antagonist), or saline. Healthy Sprague-Dawley (SD) rats (n = 20) were used as control. Left ventricular function, myocardial apoptosis, myocardial ultrastructure, Akt, GSK-3β and NF-κB phosphorylation, the expression of TNF-α, IL-6 and myeloperoxidase (MPO) were examined. Cardiac function was well preserved as evidenced by increased left ventricular ejection fraction (LVEF) and ± dp/dt (maximum speed of contraction/relaxation), along with decreased myocardial apoptotic death after TSN administration. TSN pretreatment alleviated mitochondria ultrastructure changes. TSN also enhanced Akt and GSK-3β phosphorylation and inhibited NF-κB phosphorylation, resulting in decreased TNF-α, IL-6 and MPO activities. Moreover, pretreatment with HOE140 abolished the beneficial effects of TSN: a decrease in LVEF and ± dp/dt, an inhibition of cardiomyocyte apoptosis, a destruction of cardiomyocyte mitochondria cristae, a reduction of Akt and GSK-3β phosphorylation, an enhancement of NF-κB phosphorylation and an increase of TNF-α, IL-6 and MPO production.</p> <p>Conclusion</p> <p>These data indicated that TSN is cardioprotective in the context of diabetic cardiomyopathy through kinin B2 receptor-Akt-GSK-3β dependent pathway.</p

Genomic epidemiology and characterization of Staphylococcus aureus isolates from raw milk in Jiangsu, China: emerging broader host tropism strain clones ST59 and ST398

Staphylococcus aureus is highly pathogenic and can cause disease in both humans and domestic animals. The aim of this study was to investigate the genomic epidemiology of S. aureus isolates from raw milk in Jiangsu Province, China, to identify predominant lineages and their associated genomic and phenotypic characteristics. In this study, we identified 117 S. aureus isolates collected from 1,062 samples in Jiangsu Province between 2021 and 2022. Based on whole-genome sequencing (WGS) data from 117 S. aureus isolates, molecular analyses indicated CC1-ST1 (26.50%, 31/117), CC97-ST97 (18.80%, 22/117), CC398-ST398 (10.26%, 12/117), CC8-ST630 (7.69%, 9/117) and CC59-ST59 (2.56%, 3/117) were the major lineages. The prevalence of mecA-positive strains was 11.11%. Four methicillin-resistant S. aureus (MRSA) lineages were found, including MRSA-ST59-t172 (n = 3), OS-MRSA-ST398-t011 (n = 1), MRSA-ST630-t2196 (n = 2) and OS-MRSA-ST630-t2196 (n = 7). Phenotypic resistance to penicillin (30.77%, 36/117), ciprofloxacin (17.09%, 20/117) and erythromycin (15.38%, 18/117) was observed which corresponded with resistance genotypes. All of the isolates could produce biofilms, and 38.46% (45/117) of isolates had invasion rates in mammary epithelial cells (MAC-T) of greater than 1%. Interestingly, most biofilm-producing and invading isolates harbored ebp-icaA-icaB-icaC-icaR-clfA-clfB-fnbA-fnbB-sdrC-sdrD-sdrE-map-can (27.35%, 32/117) and ebp-icaA-icaB-icaC-icaD-icaR-clfA-clfB-fnbA-fnbB-sdrC-sdrD-sdrE-map (33.33%, 39/117) adherence-associated gene patterns and belonged to lineages CC1 and CC97, respectively. Virulence factor assays showed that 47.01% of the isolates contained at least enterotoxin genes. Isolates harboring the immune evasion cluster (IEC) genes (sea, sak, chp, and scn) were predominantly categorized as STs 464, 398, and 59. IEC-positive ST398 and ST59 isolates contained a very high proportion of virulence genes located on prophages, whereas most IEC-negative ST398 clade isolates carried broad-spectrum drug resistance genes. Meanwhile, the IEC-positive ST398 clade showed a close genetic relationship with isolates from the pork supply chain and hospital surgical site infections. MRSA-ST59 strains showed the closest genetic relationship with an isolate from quick-frozen products. High-risk livestock-associated strains ST398 and MRSA-ST59 were detected in raw milk, indicating a potential public health risk of S. aureus transmission between livestock and humans. Our study highlights the necessity for S. aureus surveillance in the dairy industry

Advanced glycation end products accelerate ischemia/reperfusion injury through receptor of advanced end product/nitrative thioredoxin inactivation in cardiac microvascular endothelial cells.

The advanced glycation end products (AGEs) are associated with increased cardiac endothelial injury. However, no causative link has been established between increased AGEs and enhanced endothelial injury after ischemia/reperfusion. More importantly, the molecular mechanisms by which AGEs may increase endothelial injury remain unknown. Adult rat cardiac microvascular endothelial cells (CMECs) were isolated and incubated with AGE-modified bovine serum albumin (BSA) or BSA. After AGE-BSA or BSA preculture, CMECs were subjected to simulated ischemia (SI)/reperfusion (R). AGE-BSA increased SI/R injury as evidenced by enhanced lactate dehydrogenase release and caspase-3 activity. Moreover, AGE-BSA significantly increased SI/R-induced oxidative/nitrative stress in CMECs (as measured by increased inducible nitric oxide synthase expression, total nitric oxide production, superoxide generation, and peroxynitrite formation) and increased SI/R-induced nitrative inactivation of thioredoxin-1 (Trx-1), an essential cytoprotective molecule. Supplementation of EUK134 (peroxynitrite decomposition catalyst), human Trx-1, or soluble receptor of advanced end product (sRAGE) (a RAGE decoy) in AGE-BSA precultured cells attenuated SI/R-induced oxidative/nitrative stress, reduced SI/R-induced Trx-1 nitration, preserved Trx-1 activity, and reduced SI/R injury. Our results demonstrated that AGEs may increase SI/R-induced endothelial injury by increasing oxidative/nitrative injury and subsequent nitrative inactivation of Trx-1. Interventions blocking RAGE signaling or restoring Trx activity may be novel therapies to mitigate endothelial ischemia/reperfusion injury in the diabetic population

From Transistors to Phototransistors by Tailoring the Polymer Stacking

It is universally acknowledged that highly photosensitive transistors are strongly dependent on the high carrier mobility of polymer-based semiconductors. However, the polymer π–π stacking and aggregation, required to increase the charge mobility, conversely inhibit the dissociation of photogenerated charge carriers, in turn accelerating the geminate recombination of electron-hole pairs. To explore the effects of charge mobility and polymer stacking on the photoresponsivity of the phototransistors, here, two alternating copolymers are synthesized, namely P-PPAB-IDT and P-PPAB-BDT, by palladium-catalyzed Stille coupling of PPAB with indaceodithiophene (IDT) or benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl) (BDT) monomers. The polymer P-PPAB-IDT demonstrates a nearly 20 times enhancement in the hole mobility compared to P-PPAB-BDT. Yet, P-PPAB-IDT surprisingly shows no response to white light illumination, whereas P-PPAB-BDT exhibits a significant photoresponse to the same light source with a high light-current/dark-current (Ilight/Idark) ratio of 21.6 in the p-type area and a low current ratio of just 5.2 in the n-type area. It is believed that this work will provide an effective strategy to develop highly photosensitive polymer semiconductors by reducing polymer stacking and aggregation rather than improving the charge carrier mobility.acceptedVersionPeer reviewe

Sulfonated Dopant-Free Hole-Transport Material Promotes Interfacial Charge Transfer Dynamics for Highly Stable Perovskite Solar Cells

The integration of a functional group into dopant-free hole-transport materials (HTMs) to modify the perovskite|HTM interface has become a promising strategy for high-performance and stable perovskite solar cells (PSCs). In this work, a sulfonated phenothiazine-based HTM is reported, namely TAS, which consists of a butterfly structure with a readily synthesized N,​N-​bis[4-​(methylthio)​phenyl]​aniline side functional group. The interaction between TAS and perovskite via Pb–S bond induces a dipole moment that deepens the valence band of perovskite and thereby leads to enhanced open-circuit voltage in corresponding n-i-p PSCs. More importantly, the functionalization of perovskite surface via Pb–S bond promotes the hole extraction reaction while suppressing the interfacial non-radiative recombination, contributing to a 20–50% performance improvement compared to less- (4-​(methylthio)​-​N-​[4-​(methylthio)​phenyl]​aniline, DAS) or non-interacting (N,N-bis(4-methoxyphenyl)aniline, TAO) counterparts. Consequently, TAS-based PSCs exhibit superior device stability with a high PCE retention (>90% of the initial value) after 125 days of storage in the air.acceptedVersionPeer reviewe