Prophages domesticated by bacteria promote the adaptability of bacterial cells

Prophages are temperate phages integrated into the host bacterial genome.They play an important role in the adaptation and the pathogenicity of bacteria,especially pathogenic bacteria.In this review,we described the distribution of prophages in different hosts and different environments,and focused on the significance of prophages.At the singlecell level,prophages can help the host adapt to harsh external environments by directly carrying virulence genes,encoding regulatory factors and activating lysogeny.At the population level,prophages can influence the overall evolutionary direction and ecological function of the host bacterial community.This review will help us understand the important role of prophages as unique organisms in individual bacteria and microbial populations.

Enhanced n-Type Thermoelectric Performance of Conjugated Polymers Based on an Indandione-Terminated Quinoidal Unit through Comonomer Optimization

Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.

Direct Arylation Polycondensation of Thiophene-Based C−H Monomers

Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.

Retina-inspired organic neuromorphic vision sensor with polarity modulation for decoding light information

The neuromorphic vision sensor(NeuVS),which is based on organic field-effect transistors(OFETs),uses polar functional groups(PFGs)in polymer dielectrics as interfacial units to control charge carriers.However,the mechanism of modulating charge transport on basis of PFGs in devices is unclear.Here,the carboxyl group is introduced into polymer dielectrics in this study,and it can induce the charge transfer process at the semiconductor/dielectric interfaces for effective carrier transport,giving rise to the best device mobility up to 20 cm^(2) V^(−1) s^(−1) at a low operating voltage of−1 V.Furthermore,the polarity modulation effect could further increase the optical figures of merit in NeuVS devices by at least an order of magnitude more than the devices using carboxyl group-free polymer dielectrics.Additionally,devices containing carboxyl groups improved image sensing for light information decoding with 52 grayscale signals and memory capabilities at an incredibly low power consumption of 1.25 fJ/spike.Our findings provide insight into the production of high-performance polymer dielectrics for NeuVS devices.

不同网络结构特征下呼吸道传播病毒传播动力学研究

呼吸道传播病毒传播动力学特征的研究对于预测病毒传播趋势、掌握病毒传播特性、推演病毒传播控制策略至关重要。在病毒传播动力学研究方面,传统上采用系统动力学方法构建病毒传播仓室模型进行模拟和病毒传播推演,其中最为典型的病毒传播仓室模型是SIR(易感susceptible、感染infective、清除removal)[1]模型。

Calculation aided miscibility manipulation enables highly efficient polythiophene:nonfullerene photovoltaic cells

Polythiophenes,with merits of low cost and high scalability of synthesis,have received growing interest in organic solar cells.To date,the best-performing polythiophene:nonfullerene solar cells exhibit typical power conversion efficiencies (PCEs) of 10%–12%,which is much lower than those employing PM6-and D18-type polymers.This inferior performance is mostly limited by the improper miscibility between polythiophene and acceptors.Efforts on engineering the molecular structure to systematically tune the miscibility are required.With the aid of group contribution calculations,the miscibility of polythiophene:nonfullerene blend system was finely tuned by varying the ratios of siloxane-terminated chains and alkyl chains in ester-substituted polythiophenes through random copolymerization.Based on a series of the polythiophene and nonfullerene acceptors,the detailed analysis of blend miscibility and performance reveals a surprising anticorrelation between the Flory-Huggins interaction parameter (χ_(aa)) and the optimal time of solvent vapor annealing for device performance across these systems.Primarily due to the slightly higher χ_(aa),the blend of PDCBT-Cl-Si5 and ITIC-Th1 results in a record-high PCE of 12.85%in polythiophene:nonfullerene solar cells.The results not only provide a calculation-guided approach for molecular design but also prove that precise control of the miscibility is an effective way to design high-performance polythiophene:nonfullerene blends and beyond.

Low-bandgap conjugated polymers based on benzodipyrrolidone with reliable unipolar electron mobility exceeding 1 cm^(2) V^(-1)s^(-1)

The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.

Dithienocarbazole- and benzothiadiazole-based donor-acceptor conjugated polymers for bulk heterojunction polymer solar cells

Donor-acceptor(D-A)-conjugated polymers P(BT-C1)and P(BT-C2),with dithieno[2,3-b;7,6-b]carbazole(C1)or dithieno[3,2-b;6,7-b]carbazole(C2)as D-unit and benzothiadiazole(BT)as A-unit,were synthesized.The optical bandgaps of the polymers are similar(1.84 and 1.88 e V,respectively).The structures of donor units noticeably influence the energy levels and backbone curvature of the polymers.P(BT-C1)shows a large backbone curvature;its highest occupied molecular orbital(HOMO)energy level is 5.18 e V,whereas P(BT-C2)displays a pseudo-straight backbone and has a HOMO energy level of 5.37 e V.The hole mobilities of the polymers without thermal annealing are 1.9×10 3 and 2.7×10 3 cm2 V 1 s 1 for P(BT-C1)and P(BT-C2),respectively,as measured by organic thin-film transistors(OTFTs).Polymer solar cells using P(BT-C1)and P(BT-C2)as the donor and phenyl-C71-butyric acid methyl ester(PC71BM)as the acceptor were fabricated.Power conversion efficiencies(PCEs)of 4.9%and 5.0%were achieved for P(BT-C1)and P(BT-C2),respectively.The devices based on P(BT-C2)exhibited a higher Voc due to the deeper HOMO level of the polymer,which led to a slightly higher PCE.

基于增强电子传输的双层MXene/半导体高性能n型薄膜晶体管

电介质/半导体的界面工程是制备高性能有机场效应晶体管的关键.本工作提出采用MXene/半导体双层结构制备高性能n型晶体管,其中载流子的形成和调控发生在二氧化硅/半导体界面,同时高迁移率和长横向尺寸的MXene纳米片作为主要的电荷传输通道.通过调节MXene纳米片的互连度,优化了器件的电学性能.与单层N2200晶体管相比,MXene/N2200晶体管表现出显著增强的n型特性,包括提升100倍的场效应迁移率、10^(4)电流开关比以及0.64 V dec^(-1)亚阈值摆幅.MXene/N2200晶体管的高性能归因于MXene纳米沟道的电负性和高迁移率.电负性显著增强了电子从N2200向MXene沟道的转移,而高迁移率使得电子有效传输至电极.MXene/p型半导体晶体管却表现出受抑制的p型性能,这是因为MXene纳米片具有高度电负性.此外,本文提出的双层MXene/n型半导体结构也具有良好的结构普适性和高性能优势.这些结果表明双层MXene/半导体结构有望应用于高性能n型晶体管的制备.

High T_(g) Polymer Insulator Yields Organic Photovoltaic Blends with Superior Thermal Stability at 150℃

Record-breaking organic solar cells(OSCs)based on blends of polymer donors and small molecule acceptors often show undesirable degradati on,which severely precludes their practical use.Herei n,we demonstrate a facile and cost-effective approach to con struct thermally stable OSCs at 150℃ by incorporating a small amount of a polymer insulator polyacenaphthylene(PAC)with high glass-transition temperature over 230℃ into polymer:acceptor blends.The model PTB7-Th:EH-IDTBR blend with 10 wt%PAC maintained above 85%of its initial efficiency upon continuous heating at 150℃ for over 800 h,while the efficiency of the blend without PAC sharply dropped by 70%after-300 h.Owing to high miscibility with acceptors,PAC confines the motion of the acceptor molecules and suppresses the acceptor crystallization at elevated temperatures,leading to significantly improved stability.Importantly,the effectiveness of this blending approach was also validated in many other OSC systems,showing great potential for achieving high-performance thermally stable electronics.

Fusing Thienoisoindigo to the Conjugated Ribbons with Strong Absorption in the Second Near-Infrared Window

Organic dyes with strong absorption in the second near-infrared(NIR-II)window(1000-1700 nm)have multiple applications.However,the design and synthesis of stable NIR-II absorbing organic dyes are very challenging and constantly defy our synthetic ability.In this work,we have successfully synthesized a series of soluble and stable fused thienoisoindigo(nThIID)ribbons.The absorption maximum(λ_(max))of the ribbons increases from 644 nm of 1ThIID to 1252 nm of 6ThIID.Importantly,nThIIDs with n≥4 all display strong absorption in the NIR-II window with molar extinction coefficients(ε_(max))greater than 105 L mol^(−1)cm^(−1)atλmax.These molecules are promising photothermal conversion dyes with photothermal conversion efficiencies of ca.60%under 1064 nm laser irradiation.