Alkyl chain modulation of asymmetric hexacyclic fused acceptor synergistically with wide bandgap third component for high efficiency ternary organic solar cells

Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology of blend film,thereby improving charge mobility and reducing energy loss within the corresponding film.Notably,the PM6:BP4F-UU device exhibited a higher open-circuit voltage(V_(oc))of 0.878 V compared to the PM6:BP4F-HU device with a V_(oc)of 0.863 V.Further,a new wide bandgap SMA named BTP-TA was designed and synthesized as the third component to the PM6:BP4F-UU host binary devices,which showed an ideal complementary absorption spectrum in PM6:BP4F-UU system.In addition,BTP-TA can achieve efficient intermolecular energy transfer to BP4F-UU by fluorescence resonance energy transfer(FRET)pathway,due to the good overlap between the photoluminescence(PL)spectrum of BTP-TA and the absorption region of BP4F-UU.Consequently,ternary devices with 15wt%BTP-TA exhibits broader photon utilization,optimal blend morphology,and reduced charge recombination compared to the corresponding binary devices.Consequently,PM6:BP4F-UU:BTP-TA ternary device achieved an optimal power conversion efficiency(PCE)of 17.83%with simultaneously increased V_(oc)of 0.905 V,short-circuit current density(J_(sc))of 26.14 mA/cm^(2),and fill factor(FF)of 75.38%.

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].

二苯乙烯苷对HepG2细胞胆固醇含量的影响及其作用机制研究

目的探索二苯乙烯苷对HepG2细胞胆固醇含量的影响及其作用机制。方法将细胞随机分为正常组、模型组(ox-LDL 50 mg/L)、A组(ox-LDL 50 mg/L+二苯乙烯苷250μmol/L)、B组(ox-LDL50 mg/L+二苯乙烯苷188μmol/L)、C组(ox-LDL 50 mg/L+二苯乙烯苷125μmol/L)及D组(ox-LDL50 mg/L+二苯乙烯苷62.5μmol/L)。细胞处理48 h后,采用油红O脂肪染色法观察、胆固醇测定试剂盒测定各组胆固醇的含量并用逆转录聚合酶链反应检测肝癌HepG2细胞ABCG1、ABCA1及SR-BI的表达水平。结果正常组、A、B、C和D组细胞内总胆固醇(TC)、细胞内游离胆固醇(FC)含量均低于模型组(P <0.05),同时A、B、C和D组上清TC和FC含量较正常组升高(P<0.05)。二苯乙烯苷能够降低HepG2细胞内胆固醇含量,增加胆固醇外流率(P<0.05),其中二苯乙烯苷浓度为125μmol/L时达最高值。模型组细胞ABCA1 mRNA表达水平较正常组下降(P<0.05)。A、B、C和D组ABCA1、ABCG1和SR-BI mRNA表达水平较模型组上升(P<0.05)。结论二苯乙烯苷能够降低HepG2细胞胆固醇的含量,其机制可能是通过上调ABCA1、ABCG1和SR-BI的表达水平而增加胆固醇外流。

Optimizing side chains on different nitrogen aromatic rings achieving 17% efficiency for organic photovoltaics

Balancing charge generation and low energy loss(E_(loss)), especially in the wide spectral absorption region is critical to obtain high-performance organic photovoltaics(OPVs). Therefore, Y11-M and Y11-EB are designed and synthesized through modifying alkyl chains on different nitrogen aromatic rings of the reported non-fullerene acceptor Y11. Although all the molecules have almost similar low band-gap(around 1.30 e V), Y11-M and Y11-EB exhibit wider absorption in 410–870 nm region. Eventually, the conventional devices based on Y11-M and Y11-EB possess more efficient charge generation with low Eloss(around 0.44 e V). In addition, outstanding efficiencies of 16.64% and 17.15% with the fill factor of 76.15% and 74.73% are obtained in PM6:Y11-M and PM6:Y11-EB-based devices, both higher than Y11:PM6. The results highlight the importance of rational alkyl chains optimization, and a good structureproperty relationship is established as well.

Twisted Poisson Homology of Truncated Polynomial Algebras in Four Variables

In this paper, we study the twisted Poisson homology of truncated polynomials algebra A in four variables, and we calculate exactly the dimension of i-th (i = 1, 2, 3, 4) twisted Poisson homology group over A by the induction on the length. The calculation methods provided in this paper can also solve truncated polynomials algebra in a few variables.

Stereochemical editing:Catalytic racemization of secondary alcohols and amines

Chiral alcohols and amines are important structural units widely existing in pharmaceuticals,agrochemicals,and food additives.Dynamic kinetic resolution(DKR)is an efficient strategy to deliver optically active alcohols and amines from their racemates.For the development of DKR method,racemization catalyst plays as a crucial element with the requirement of compatibility with the kinetic resolution(KR)system.In this paper,recent advance in the catalytic racemization of secondary alcohols and amines is summarized based on different types of racemizing intermediates,which are redox racemization via ketone/imine intermediates,racemization via radical intermediates,and racemization via carbocation intermediates.Enzymatic racemization of secondary alcohols and amines is also enclosed.

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

The development of A-DA′D-A type small molecule acceptors(SMAs)has promoted the rapid progress of polymer solar cells(PSCs)in recent years.The outer side chains on the terminal thiophene ring and inner side chains on nitrogen atoms of the pyrrole ring of the DA′D fused ring play important roles in the photovoltaic performance of the SMAs.Here,we synthesized two new SMAs,2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-bis(4-(2-ethylhexyl)thiophen-2-yl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methaneylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(T2EH)and 2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-bis(3-(2-ethylhexyl)phenyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methaneylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)(P2EH),with 2-ethylhexylβ-substituted thienyl or phenyl as the outer side chains,respectively,to improve the photovoltaic properties of the SMAs.Compared with P2EH,T2EH exhibits closerπ−πstacking,slightly red-shifted absorption,and higher electron mobility.Moreover,the active layer of T2EH blended with the low-cost polymer donor poly[(thiophene)-alt-(6,7-difluoro-2-(2-hexyldecyloxy)quinoxaline)](PTQ10)possesses higher mobilities,a longer lifetime,and less recombination of the charge carriers in comparison with that of the PTQ10:P2EH active layer.Eventually,the PTQ10:T2EH-based PSCs showed an outstanding power conversion efficiency(PCE)of 18.55%,while the PSC based on PTQ10:P2EH displayed a PCE of 17.50%.Importantly,18.55%is the highest PCE in the PTQ10-based binary PSCs so far.The results indicate that T2EH is one of the best SMAs for the PTQ10-based PSCs and is a promising SMA for the application of PSCs.

A-DA’D-A Type Pentacyclic Small Molecule Acceptors to Exceed 16.5%Efficiency by Heteroatom Effect at the Outer Side Chain

Comprehensive Summary In this work,we adopt a“heteroatom side-chains”modification strategy to modify the thiophene units in A-DA'D-A(acceptor-donor-acceptor’-donor-acceptor)type pentacyclic SMAs(small molecule acceptors),that is,introducing branched alkyl chain at theβ-position of thiophene instead of straight alkyl chain,and then introducing oxygen atom at the third-position on the basis of branched chain.Two new pentacyclic SMAs(BZ4F-EH and BZ4F-OEH)were synthesized,and the influence of the heteroatom side-chains on photoelectric properties of A-DA'D-A type pentacyclic SMAs was systematically studied.Compared with our previously reported BZ4F(Y26),BZ4F-EH shows slightly blue-shifted absorption,while BZ4F-OEH has obvious red-shifted absorption.As a result,BZ4F-OEH-based binary device achieved a high power conversion efficiency(PCE)of 16.56%with a fill factor(FF)of 79.3%,which is the highest efficiency of pentacyclic SMAs to date.

High-Performance D-A Copolymer Donor Based on Difluoroquinoxaline A-Unit with Alkyl-Chlorothiophene Substituents for Polymer Solar Cells

Side chain engineering with fluorine substitution is widely used to enhance photovoltaic performance of polymer donors in the research field of polymer solar cells(PSCs).However,fluorine substitution has disadvantages of complicated synthesis and high cost.Herein,we synthesized a novel D-A copolymer donor PBQ9 based on difluoroquinoxaline A-unit with chlorine substitution on its alkyl-thiophene side chains instead of fluorine substitution in the polymer donor PBQ6,which greatly shortens the synthetic route and reduces the cost.Interestingly,the optimized binary PSC with PBQ9 as polymer donor and m-TEH as acceptor demonstrated a high power conversion efficiency(PCE)of 18.81%(certified PCE of 18.33%by National Institute of Metrology,China)with a high fill factor of 80.59%,and the photovoltaic performance of the PSCs is insensitive to the different batches of the polymer donor.The results indicate that PBQ9 is a high-performance polymer donor and that chlorine substitution is an effective strategy to improve photovoltaic performance and reduce the cost of polymer donors.

Temporal dynamics of SARS-CoV-2 genome mutations that occurred in vivo on an aircraft

We analyzed variations in the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)genome during a flight-related cluster outbreak of coronavirus disease 2019(COVID-19)in Shenzhen,China,to explore the characteristics of SARS-CoV-2 transmission and intra-host single nucleotide variations(iSNVs)in a confined space.Thirty-three patients with COVID-19 were sampled,and 14 were resampled 3-31 days later.All 47 nasopharyngeal swabs were deep-sequenced.iSNVs and similarities in the consensus genome sequence were analyzed.Three SARS-CoV-2 variants of concern,Delta(n=31),Beta(n=1),and C.1.2(n=1),were detected among the 33 patients.The viral genome sequences from 30 Delta-positive patients had similar SNVs;14 of these patients provided two successive samples.Overall,the 47 sequenced genomes contained 164 iSNVs.Of the 14 paired(successive)samples,the second samples(T2)contained more iSNVs(median:3;95%confidence interval[95%CI]:2.77-10.22)than did the first samples(T1;median:2;95%CI:1.63-3.74;Wilcoxon test,P=0.021).38 iSNVs were detected in T1 samples,and only seven were also detectable in T2 samples.Notably,T2 samples from two of the 14 paired samples had additional mutations than the T1 samples.The iSNVs of the SARS-CoV-2 genome exhibited rapid dynamic changes during a flight-related cluster outbreak event.Intra-host diversity increased gradually with time,and new site mutations occurred in vivo without a population transmission bottleneck.Therefore,we could not determine the generational relationship from the mutation site changes alone.

A chlorinated non-fullerene acceptor for efficient polymer solar cells

Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize the photoelectric properties is reported.A new narrow bandgap(1.30 eV)chlorinated non-fullerene electron acceptor(Y15),based on benzo[d][1,2,3] triazole with two 3-undecylthieno[2’,3’:4,5] thieno[3,2-b] pyrrole fused-7-heterocyclic ring,with absorption edge extending to the near-infrared(NIR) region,namely A-DA’D-A type structure,is designed and synthesized.Its electrochemical and optoelectronic properties are systematically investigated.Benefitting from its NIR light harvesting,the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency(PCE) of 14.13%,when blending with a wide bandgap polymer donor PM6.Our results show that the A-DA’D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells(PSCs).

Chlorinated polymerized small molecule acceptor enabling ternary all-polymer solar cells with over 16.6% efficiency

Recently,all-polymer solar cells(all-PSCs) based on polymerized small molecule acceptors(PSMAs) have achieved significant progress.Ternary blending has proven to be an effective strategy to further boost the power conversion efficiency(PCE) of the all-PSCs.Herein,a new A-DA′D-A small-molecule acceptor-based PSMA(named as PYCl-T) was designed and synthesized,which possesses similar polymer backbone with the widely used PY-IT,but with chlorine substitution on the A-end groups in the A-DA′D-A structure.PYCl-T was then employed as the third component into the PM6:PY-IT system and the ternary all-PSCs based on PM6:PY-IT:PYCl-T demonstrated a high PCE of 16.62%(certified value of 16.3%).Moreover,the PCE of 15.52% was realized in the enlarged ternary all-PSCs with effective area of 1 cm^(2),indicating the great potential in large-scale applications.Moreover,the optimized ternary blend films of PM6:PY-IT:PYCl-T show excellent thermal stability at 150 ℃.This work demonstrates that the utilization of a ternary blend system involving two well-compatible PSMA polymer acceptors is an effective strategy to boost the performance of the all-PSCs.

Stable perovskite solar cells with efficiency of 22.6%via quinoxaline-based polymeric hole transport material

Poor stability of spiro-OMe TAD hole transport materials(HTMs)with dopant is a major obstacle for the commercialization of perovskite solar cells(pero-SCs).Herein,we demonstrate a series of quinoxaline-based D-A copolymers PBQ5,PBQ6 and PBQ10 as the dopant-free polymer HTMs for high performance pero-SCs.The D-A copolymers are composed of fluorothienyl benzodithiophene(BDTT)as D-unit,difluoroquinoxaline(DFQ)with different side chains as A-unit,and thiophene asπ-bridge,where the side chains on the DFQ unit are bi-alkyl for PBQ5,bi-alkyl-fluorothienyl for PBQ6,and alkoxyl for PBQ10.All the three copolymers are adopted as the dopant-free HTM in the pero-SCs.The planar n-i-p structured pero-SCs based on(FAPb I_(3))_(0.98)(MAPb Br_(3))_(0.02)with PBQ6 HTM demonstrated the high power conversion efficiency(PCE)of 22.6%with Vocof1.13 V and FF of 80.8%,which is benefitted from the suitable energy level and high hole mobility of PBQ6.The PCE of 22.6%is the highest efficiency reported in the n-i-p structured pero-SCs based on dopant-free D-A copolymer HTM.In addition,the peroSCs show significantly enhanced ambient,thermal and light-soaking stability compared with the devices with traditional spiroOMe TAD HTM.

Gene duplication drove the loss of awn in sorghum.

Loss of the awn in some cereals including sorghum is a key transition during cereal domestication or improvement that has facilitated grain harvest and storage.The genetic basis for the loss of awn in sorghum during domestication or improvement remains unknown.Here,we identified a transcription factor gene awn1 encoding an ALOG domain,which is responsible for awn loss during sorghum domestication or improvement.awn1 arose from a gene duplication from chromosome 10 that translocated to chromosome 3,recruiting a new promoter from the neighbouring intergenic region filled with"noncoding DNA",and recreating the first exon and intron.The awn1 acquires high expr`ession after duplication and represses the elongation of awns in domesticated sorghum.Comparative mapping revealed a high collinearity at awn1 paralog locus on chromosome 10 across cereals and awn growth and development was successfully reactivated on the rice spikelet by inactivating rice awn1 orthologue.Further RNA-seq and DAP-seq revealed that as a transcription repressor,AWN1 directly bound to the motif in the regulatory regions from three MADS genes related to flower development and two genes DL and LKS2 for the development of awn,downregulated the expressions of these genes,and then repressed the elongation of awn.The preexistence of regulatory elements in the neighbouring intergenic region of awn1 before domestication signified that noncoding DNA may serve as a treasure trove for evolution during adaptation to a changing world.Our results supported that gene duplication can promptly drive the evolution of gene regulatory network.

辛基取代喹喔啉聚合物给体使全聚合物有机太阳能电池的效率超过17%

本文设计并合成了一种新型喹喔啉类聚合物给体PBQ8,其在喹喔啉单元上具有正辛基侧链,与先前报道的PBQ5(异辛基侧链)具有相同的聚合物骨架结构.与PBQ5相比,PBQ8表现出更强的分子间相互作用和更好的分子堆积.当其与聚合物受体PY-IT共混时,基于PBQ8:PY-IT的全聚合物太阳能电池表现出远高于PBQ5:PY-IT器件效率,其能量转化效率为17.04%,这是目前全聚合物太阳能电池中的最高效率之一.结果表明,聚合物给体的侧链工程是进一步提高全聚合物太阳能电池光伏性能的有效途径.

Whole-Genome Sequences Analysis Displays Relationship of SARS-CoV-2 Delta Variant Between Four Local Cases and Passengers of a Flight from South Africa—Shenzhen City,Guangdong Province,China,June 2021

On June 14,2021,a customs officer(Case A)went to the infirmary at Baoan International Airport in Shenzhen due to a runny nose and fever.He was admitted to the Central Hospital of Baoan immediately.This patient preliminarily tested positive for coronavirus disease 2019(COVID-19)infection,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),using a quantitative realtime reverse transcription polymerase chain reaction(qRT-PCR)method in this hospital.Then,a mixed specimen of nasopharyngeal swab.

Realization of Poisson enveloping algebra

为泊松代数学，泊松模块的范畴等价于它包围的泊松的模块范畴代数学，在此包围的泊松代数学是联合的。在这篇文章，为多项式代数学 S 上的泊松结构，我们首先构造泊松代数学 R，然后证明包围的泊松 S 的代数学对 R 的使量子化的通用包围代数学的专门化同形，因此，是 R 的变丑量子化。

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.

Honeycomb-Like Hydrogel Microspheres for 3D Bulk Construction of Tumor Models

A two-dimensional(2D)cell culture-based model is widely applied to study tumorigenic mechanisms and drug screening.However,it cannot authentically simulate the threedimensional(3D)microenvironment of solid tumors and provide reliable and predictable data in response to in vivo,thus leading to the research ilusionis and failure of drug screening.In this study,honeycomb-like gelatin methacryloyl(GelMA)hydrogel microspheres are developed by synchronous photocrosslinking microluidic technique to construct a 3D model of osteosarcoma.The in vitro study shows that ostcosarcoma cells(K7M2)culured in 3D GelMA microspheres have stronger tumorous stemness。proliferation and migration abilitics,more osteoclastogenetic ability,and reistance to chemotherapeutic drugs(DOX)than that of cells in 2D cultures.More imporantly,the 3D-cultured K7M2 cells show more tumorigenicity in immunologically sound mice,characterized by shorter tumorigenesis time,larger tumor volumc,severe bone destruction,and higher mortality.In conclusion,honeycomb like porous microsphere scaffolds are constructed with uniform structure by micofluidic technology to massively produce tumor cells with original phenotypes.Those microspheres could recapitulate the physiology microenvironment of tumors.maintain ell-cell and cell-extracellular matrix interactions,and thus provide an efective and convenient strategy for tumor pathogenesis and drug screening research.

Manipulating molecular aggregation and crystalline behavior of A-DA’D-A type acceptors by side chain engineering in organic solar cells

Alkyl chains engineering plays an important role in photovoltaic materials for organic solar cells.Herein,three A-DA’D-A(acceptor–donor–acceptor’–donor–acceptor)type acceptors named Y6,Y6-C4,and Y6-C5 with different branching position on the pyrrole motif are discussed and the relationship between molecular aggregation,crystalline,and device performance are systematically investigated.The distance between the branching position and the main backbone affects their optical absorption and energy levels.Y6-C4 and Y6-C5 with the branching position at the fourth and fifth carbon of the alkyl chain show blue-shifted absorption and increased electrochemical bandgaps,compared with Y6 with the branching position at the second carbon of the alkyl side chain.In addition,this distance influences the molecular aggregation and crystalline behavior of the donor/acceptor blends.Compared with Y6-C4,Y6-C5 possesses a stronger crystalline and aggregate ability in the blends with a lower non-radiative energy loss,which results in a higher open circuit voltage(Voc)of 0.88 V.Finally,Y6-C5-based binary device achieved a high power conversion efficiency up to 16.73%with afill factor(FF)of 0.78.These results demonstrate that the side chain engineering is an effective strategy for tuning the molecular aggregation and crystalline to improve photovoltaic performance of the A-DA’D-A type acceptors.