A new non-fullerene acceptor based on the heptacyclic benzotriazole unit for efficient organic solar cells

Non-fullerene acceptors(NFAs)become an interesting family of organic photovoltaic materials,and have attracted considerable interest for their great potential in manufacturing large-area flexible solar panels by low cost coating methods[1–5].Recently,our group proposed in the first time an A-DA’D-A molecular strategy and synthesized a new class of non-fullerene acceptor Y6 with a record efficiency above 15%with single junction organic solar cells(OSCs)[6].To further improve the photovoltaic performance of OSCs,many effective strategies have been successfully explored,such as side-chain engineering and extension of fused core and terminal group engineering[7–12].As well-known,PCE of devices is determined by the open circuit voltage(Voc),short-circuit current density(Jsc)and fill factor(FF)[13].Among them,Voc is associated with low-lying highest occupied molecular orbital(HOMO)of donor and lowest unoccupied molecular orbital(LUMO)of acceptor of the active layer[14–16].Side-chain engineering is an effective strategy for manipulating energy levels and improving photovoltaic performance of devices[17–19].For example,introducing the alkyl/alkoxy chains can effectively tune the HOMO/LUMO energy levels[20–22].Tang et al.have reported a novel non-fullerene acceptor ITC6-IC.ITC6-IC has relatively high LUMO level and high Voc than those of ITIC due to the introduction of weak electrondonating hexyl group on thiophene[23].

Description of two new species of Pseudoaliinostoc(Nostocales,Cyanobacteria)from China based on the polyphasic approach

Two cyanobacterial strains CHAB5870 and CHAB5871 morphologically identifi ed as Nostoc-like species were isolated from different habitats in China,and they were phylogenetically and taxonomically characterized based on a polyphasic approach combining morphological,ecological,and molecular data.In the 16S rRNA gene phylogeny inferred using maximum likelihood,maximum-parismony,and bayesian inference methods,these two strains clustered within the Pseudoaliinostoc clade.The 16S rRNA gene sequences of these two strains displayed≥95.5%and≤98%similarity to Pseudoaliinostoc species,which indicated them to represent new species of the genus Pseudoaliinostoc.Furthermore,the unique pattern of D1-D1′and Box-B helix of the 16S–23S rRNA internal transcribed spacer(ITS)secondary structure also revealed that two strains represented novel species.These results supported the establishment of two new Pseudoaliinostoc species with the name P.jiangxiense sp.nov.and P.yunnanense sp.nov.

Diflurobenzothiadiazole core-based noncovalently fused small molecule acceptor exhibiting over 12% efficiency and high fill factor

The versatility and flexibility of organic photoelectric materials endow organic photovoltaic cells fine function modulation and huge commercial potential. In this work, a new noncovalent fused-ring small molecule acceptor(SMA) BID-4 F has been synthesized for high-efficient organic solar cells(OSCs). BID-4 F consists of a diflurobenzothiadiazole(DFBT) core, ladder-like indacenodithiophene(IDT) spacers, and dicyanoindanone electron-withdrawing end groups, which are supposed to be conformationally interlocked by noncovalent interactions, leading to good molecular planarity. In addition, compact solid state stacking was revealed by UV–vis–NIR absorption spectrum. The optimized PM6:BID-4 F based device delivers an eminent power conversion efficiency(PCE) of 12.30% with a high open-circuit voltage(Voc) of 0.92 V and a high fill factor(FF) of 74.3%. Most importantly, the PCE and FF are among one of the highest values reported for the OSCs based on the unfused-ring SMAs. Overall, our work demonstrates that the unfused ring central framework with high molecular planarity through noncovalent interactions provides a good strategy to construct highly efficient SMAs.

ADT-OH improves intestinal barrier function and remodels the gut microbiota in DSS-induced colitis

Owing to the increasing incidence and prevalence of inflammatory bowel disease(IBD)worldwide,effective and safe treatments for IBD are urgently needed.Hydrogen sulfide(H2S)is an endogenous gasotransmitter and plays an important role in inflammation.To date,H2S-releasing agents are viewed as potential anti-inflammatory drugs.The slow-releasing H_(2)S donor 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione(ADT-OH),known as a potent therapeutic with chemopreventive and cytoprotective properties,has received attention recently.Here,we reported its anti-inflammatory effects on dextran sodium sulfate(DSS)-induced acute(7 days)and chronic(30 days)colitis.We found that ADT-OH effectively reduced the DSS-colitis clinical score and reversed the inflammation-induced shortening of colon length.Moreover,ADT-OH reduced intestinal inflammation by suppressing the nuclear factor kappa-B pathway.In vivo and in vitro results showed that ADT-OH decreased intestinal permeability by increasing the expression of zonula occludens-1 and occludin and blocking increases in myosin II regulatory light chain phosphorylation and epithelial myosin light chain kinase protein expression levels.In addition,ADT-OH restored intestinal microbiota dysbiosis characterized by the significantly increased abundance of Muribaculaceae and Alistipes and markedly decreased abundance of Helicobacter,Mucispirillum,Parasutterella,and Desulfovibrio.Transplanting ADT-OH-modulated microbiota can alleviate DSS-induced colitis and negatively regulate the expression of local and systemic proinflammatory cytokines.Collectively,ADT-OH is safe without any short-term(5 days)or long-term(30 days)toxicological adverse effects and can be used as an alternative therapeutic agent for IBD treatment.

Extracellular signal regulated kinase 5 promotes cell migration,invasion and lung metastasis in a FAK-dependent manner

This study was designed to evaluate ERK5 expression in lung cancer and malignant melanoma progression and to ascertain the involvement of ERK5 signaling in lung cancer and melanoma.We show that ERK5 expression is abundant in human lung cancer samples,and elevated ERK5 expression in lung cancer was linked to the acquisition of increased metastatic and invasive potential.Importantly,we observed a significant correlation between ERK5 activity and FAK expression and its phosphorylation at the Ser910 site.Mechanistically,ERK5 increased the expression of the transcription factor USF1,which could transcriptionally upregulate FAK expression,resulting in FAK signaling activation to promote cell migration.We also provided evidence that the phosphorylation of FAK at Ser910 was due to ERK5 but not ERK1/2,and we then suggested a role for Ser910 in the control of cell motility.In addition,ERK5 had targets in addition to FAK that regulate epithelial-to-mesenchymal transition and cell motility in cancer cells.Taken together,our findings uncover a cancer metastasis-promoting role for ERK5 and provide the rationale for targeting ERK5 as a potential therapeutic approach.

Understanding energetic disorder in electron-deficient-core-based non-fullerene solar cells

Recent advances in material design for organic solar cells(OSCs)are primarily focused on developing near-infrared nonfullerene acceptors,typically A-DA′D-A type acceptors(where A abbreviates an electron-withdrawing moiety and D,an electron-donor moiety),to achieve high external quantum efficiency while maintaining low voltage loss.However,the charge transport is still constrained by unfavorable molecular conformations,resulting in high energetic disorder and limiting the device performance.Here,a facile design strategy is reported by introducing the"wing"(alkyl chains)at the terminal of the DA′D central core of the A-DA′D-A type acceptor to achieve a favorable and ordered molecular orientation and therefore facilitate charge carrier transport.Benefitting from the reduced disorder,the electron mobilities could be significantly enhanced for the"wing"-containing molecules.By carefully changing the length of alkyl chains,the mobility of acceptor has been tuned to match with that of donor,leading to a minimized charge imbalance factor and a high fill factor(FF).We further provide useful design strategies for highly efficient OSCs with high FF.

可变剪切在植物成花转换中的作用

精确调控成花转换,确保植物在适宜环境下开花,对于植物的成功繁殖和物种繁衍至关重要。开花由多种分子机制在转录、转录后和蛋白质水平进行调控。可变剪切(AS)是一种普遍的转录后水平调控过程,可从单个基因产生多个转录本,从而丰富转录组和蛋白质组的多样性。大量研究表明,可变剪切在成花转换过程中发挥重要作用。根据发育和环境条件,AS能够影响mRNA的稳定性和/或蛋白亚型的功能,从而调控开花相关基因的功能转录本和/或功能蛋白水平。揭示成花相关pre-mRNA的AS作用将进一步增进人们对开花相关基因功能以及整个成花转换调控网络的认识。该文归纳了涉及成花转换的AS研究进展,并针对各个调控途径进行总结,以期为进一步研究植物AS和成花转换调控机制提供参考。