Judicious training pattern for superior molecular reorganization energy prediction model

Reorganization energy(RE)is closely related to the charge transport properties and is one of the important parameters for screening novel organic semiconductors(OSCs).With the rise of data-driven technology,accurate and efficient machine learning(ML)models for high-throughput screening novel organic molecules play an important role in the boom of material science.Comparing different molecular descriptors and algorithms,we construct a reasonable algorithm framework with molecular graphs to describe the compositional structure,convolutional neural networks to extract material features,and subsequently embedded fully connected neural networks to establish the mapping between features and predicted properties.With our well-designed judicious training pattern about feature-guided stratified random sampling,we have obtained a high-precision and robust reorganization energy prediction model,which can be used as one of the important descriptors for rapid screening potential OSCs.The root-meansquare error(RMSE)and the squared Pearson correlation coefficient(R^(2))of this model are 2.6 me V and0.99,respectively.More importantly,we confirm and emphasize that training pattern plays a crucial role in constructing supreme ML models.We are calling for more attention to designing innovative judicious training patterns in addition to high-quality databases,efficient material feature engineering and algorithm framework construction.

不同单细胞全基因组扩增方法的比较及MALBAC在辅助生殖中的应用

单细胞全基因组扩增(whole genome amplification,WGA)是指在单细胞水平对全基因组进行扩增的新技术,其原理是将分离的单个细胞的微量全基因组DNA进行扩增,获得高覆盖率的完整的基因组后进行高通量测序,用于揭示细胞异质性。目前,WGA方法主要包括引物延伸预扩增(primer extension preamplification PCR,PEP-PCR)、简并寡核苷酸引物PCR(degenerate oligonucleotide primed PCR,DOP-PCR)、多重置换扩增(multiple displacement amplification,MDA)、多次退火环状循环扩增(multiple annealing and looping-based amplification cycles,MALBAC)等。本文对不同的单细胞WGA方法的原理及应用情况分别进行了阐述,并对其扩增效率进行评价和比较,包括基因组覆盖度、均一性、重现性、SNV(single-nucleotide variants)和CNV(copy number variants)检测力等。综合对比不同单细胞WGA方法后发现,MALBAC的扩增均一性最高、等位基因脱扣率最低、重现性最好,且对于CNV和SNV的检测效果最好。本文还阐述了MALBAC技术在人类单精子减数重组、非整倍体分析以及人类卵细胞基因组研究中的应用。

Recent Advances in Interface Engineering for Electrocatalytic CO_(2) Reduction Reaction

Electrocatalytic CO_(2) reduction reaction(CO_(2) RR) can store and transform the intermittent renewable energy in the form of chemical energy for industrial production of chemicals and fuels,which can dramatically reduce CO_(2) emission and contribute to carbon-neutral cycle. E cient electrocatalytic reduction of chemically inert CO_(2) is challenging from thermodynamic and kinetic points of view. Therefore,low-cost,highly e cient,and readily available electrocatalysts have been the focus for promoting the conversion of CO_(2). Very recently,interface engineering has been considered as a highly e ective strategy to modulate the electrocatalytic performance through electronic and/or structural modulation,regulations of electron/proton/mass/intermediates,and the control of local reactant concentration,thereby achieving desirable reaction pathway,inhibiting competing hydrogen generation,breaking binding-energy scaling relations of intermediates,and promoting CO_(2) mass transfer. In this review,we aim to provide a comprehensive overview of current developments in interface engineering for CO_(2) RR from both a theoretical and experimental stand-point,involving interfaces between metal and metal,metal and metal oxide,metal and nonmetal,metal oxide and metal oxide,organic molecules and inorganic materials,electrode and electrolyte,molecular catalysts and electrode,etc. Finally,the opportunities and challenges of interface engineering for CO_(2) RR are proposed.

Expression,structure and function analysis of the sperm-oocyte fusion genes Juno and Izumo1 in sheep(Ovis aries)

Background:JUNO and IZUMO1 are the first receptor-ligand protein pairs discovered to be essential for spermoocyte fusion;their interaction is indispensable for fertilization.Methods:PCR was used to clone the full-length DNA sequence of the Juno gene in sheep.The single nucleotide polymorphism(SNP)loci of Juno were genotyped by Sequenom MassARRAY®.PCR combined with rapid amplification of cDNA Ends were used to clone the full-length cDNA sequence of Juno and Izumo1.Reverse transcriptase-PCR(RT-PCR)and real time-quantitative-PCR(RT-qPCR)were used to analyze the genes’expression in tissues of sheep,and single cell RNA-seq was used to analyze the genes’expression in oocytes,granulosa cells and follicular theca of polytocous and monotocous Small Tail Han ewes.Bioinformatics was used to analyze advanced structure and phylogeny of JUNO and IZUMO1 proteins.Results:The full-length DNA sequence of the Juno gene in sheep was cloned and nine SNPs were screened.We found a significant association between the g.848253 C>A locus of Juno and litter size of Small Tail Han sheep(P<0.05).The full-length cDNA sequence of Juno and Izumo1 genes from Small Tail Han sheep were obtained.We found a new segment of the Izumo1 CDS consisting of 35 bp,and we confirmed the Izumo1 gene has 9 exons,not 8.RT-qPCR showed that Juno and Izumo1 genes were highly expressed in ovarian and testicular tissues,respectively(P<0.01).Single cell RNA-seq showed Juno was specifically expressed in oocytes,but not in granulosa cells or follicular theca,while Izumo1 displayed little to no expression in all three cell types.There was no difference in expression of the Juno gene in oocyte and ovarian tissue in sheep with different litter sizes,indicating expression of Juno is not related to litter size traits.Bioinformatic analysis revealed the g.848253 C>A locus of Juno results in a nonconservative missense point mutation leading to a change from Phe to Leu at position 219 in the amino acid sequence.Conclusions:For the first time,this study systematically analyzed the expression,structure and function of Juno and Izumo1 genes and their encoded proteins in Small Tail Han sheep,providing the basis for future studies of the regulatory mechanisms of Juno and Izumo1 genes.

Enhanced Hole-Injection Property in an OLED with a Self-assembled Monolayer of Hole-Transporting TPD on Thin Au as the Anode

A thioester-functionalized triphenylamine hole-transporting molecule （TPD-SAc） was synthesized and self-assembled to form a monolayer on an ultra-thin Au film supported on indium-tin oxide glass. The modified surface was characterized by aqueous contact angle, ellipsometer, atomic force microscopy, X-ray photoelectron spectroscopy, and ultraviolet pho- toelectron spectrometer to substantiate the formation of compact and pinhole-free monolayers. The modified organic light emitting diode device [indium-tin oxide/Au （5 nm）/self-assembled monolayers （SAM）/TPD （50 nm）/Alq3 （40 nm）/TPBI （15 nm）/LiF （1 nm）/A1 （100 nm）] showed a luminance of 7303.90 cd/m^2 and a current efficiency of 8.49 cd/A with 1.78 and 2.29-fold increase, respectively, compared to the control device without SAM. The improvements were attributed to the enhanced compatibility of the organic-inorganic interface, matched energy level by introduction of an energy mediating step and superior hole-injection property of SAM molecules.

Exclusive CO_(2)-to-formate conversion over single-atom alloyed Cu-based catalysts

Electrochemical CO_(2) reduction reaction(CO_(2) RR),powered by renewable energy sources,provides an appealing approach to convert emitted CO_(2) to value-added chemicals and fuels and achieve a carbon-neutral cycle.Among various carbon-based products,formic acid(HCOOH) has been considered as a promising liquid hydrogen storage material due to its high energy density and hydrogen content.However,so far,the reported HCOOH-selective catalysts(e.g.,Bi,Sn,In,Pb and Pd) have failed in either activity(<500 mA cm^(-2)) or stability(<20 h),which significantly inhibits the industrialized feasibility of CO_(2) RR.In contrast,Cu takes the advantages of excellent activity and low cost,making it more commercially viable.To date,one of the most challenging issues of Cu-based catalysts lies in unsatisfactory selectivity,that is,tending to produce mixed products rather than specific one,due to the complicated reaction paths involved.Very recently,Zheng et al.have developed a single-atom alloy(SAAs) strategy for the exclusive CO_(2)-to-formate conversion over Cu-based catalysts.The as-prepared Pb single-atom alloyed Cu catalyst(Pb_(1)Cu)(Fig.la) exhibited near unity selectivity towards HCOOH and impressive stability,providing the prospect of industrial production of HCOOH from CO_(2).

Controlled growth of Mo2C pyramids on liquid Cu surface

Precise spatial control of 2D materials is the key capability of engineering their optical,electronic,and mechanical properties.However,growth of novel 2D Mo2C on Cu surface by chemical vapor deposition method was revealed to be seed-induced 2D growth,limiting further synthesis of complex Mo2C spatial structures.In this research,we demonstrate the controlled growth of Mo2C pyramids with numerous morphologies,which are characterized with clear terraces within the structures.The whole evolution for Mo2C pyramids in the coursed of CVD process has been detected,posing significant potential in probing growth mechanism.The formation of the Mo2C pyramids arises from the supersaturation-induced nucleation and concentration-gradient driven diffused growth of a new Mo2C layer on the edged areas of intrinsic ones,as supported by STEM imaging.This work provides a novel Mo2C-based pyramid structure and further reveals a sliding growth mechanism,which could offer impetus for the design of new 3D spatial structures of Mo2C and other 2D materials.

Insight into the Effect of Metal Cations in the Electrolyte on Performance for Electrocatalytic CO_(2)Reduction Reaction

This highlight indicates that the local electrostatic interactions between metal cations and key intermediates facilitate the electrocatalytic CO_(2) reduction reaction.Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)has been considered as a promising strategy to achieve a carbon-neutral cycle and produce valuable fuels and feedstocks.

提高喂奶量和提高开食料采食量对犊牛体架的增长哪个更重要?

近期,由于研究表明提高犊牛喂奶量增加了断奶前的平均日增重和今后的奶产量,因此人们对犊牛饲喂高水平的奶量或代乳粉的兴趣有所增加。但由宾夕凡尼亚州立大学进行的一项荟萃分析发现,犊牛开食料的摄入量对今后奶产量的影响,比奶或代乳粉的摄入量要大4倍。还有,这些研究者断定平均的日增重仅解释了3%的变异,而农场事件或饲养状况则占了未来产量的97%。此外,喂奶量或代乳粉的增加往往减少了断奶前开食料的采食量。

NIR-II Organic Photothermal Cocrystals with Strong Charge Transfer Interaction for Flexible Wearable Heaters

The organic cocrystal strategy has provided a convenient and efficient platform for preparing organic photothermal materials.However,the rapidly directional preparation of cocrystals with desirable photothermal properties remains challenging due to a lack of suitable design ideas.Here,two new photothermal cocrystals,MTC and MFC,based on acceptor molecules(TCNQ and F4TCNQ)with different electron-withdrawing capacities were quickly prepared by the coprecipitation method,aiming to explore the effect of charge transfer(CT)interaction on photothermal properties.Compared with MTC,the stronger intermolecular CT interaction in MFC facilitates extending the absorption range(from the NIR-I to the NIR-II region)and enhancing the non-radiative transition process.Under the 808 nm laser irradiation,the photothermal conversion efficiency(PCE)of MFC is 54.6%,whereas MTC displays a mere 36.8%.The MFC cocrystal was further combined with a flexible polymer substrate(HPDMS)to prepare a flexible wearable heater(HPDMS@MFC),which exhibits excellent NIR-II photothermal performance.This work points out a research direction for the rapid assembly of efficient photothermal cocrystals and additionally provides an extensive application prospect for organic photothermal cocrystals in the field of wearable devices.

Polymer: Non-fullerene acceptor heterojunction-based phototransistor for short-wave infrared photodetection

It remains full of challenge for extending short-wave infrared(SWIR)spectral response and weak-light detection in the context of broad spectral responses for phototransistor.In this work,a novel poly(2,5-bis(4-hexyldodecyl)-2,5-dihydro-3,6-di-2-thienyl-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-thiophene)(PDPPT3-HDO):COTIC-4F organic bulk-heterojunction is prepared as active layer for bulk heterojunction phototransistors.PDPPT3-HDO serves as a hole transport material,while COTIC-4F enhances the absorption of SWIR light to 1020 nm.As a result,smooth and connected PDPPT3-HDO film is fabricated by blade coating method and exhibits high hole mobility up to 2.34 cm^(2)·V^(-1)·s^(-1) with a current on/off ratio of 4.72×10^(5) in organic thin film transistors.PDPPT3-HDO:COTIC-4F heterojunction phototransistors exhibit high responsivity of 2680 A·W^(-1) to 900 nm and 815 A·W^(-1) to 1020 nm,with fast response time(rise time~20 ms and fall time~100 ms).The photosensitivity of the heterojunction phototransistor improves as the mass ratio of non-fullerene acceptors increases,resulting in an approximately two orders of magnitude enhancement compared to the bare polymer phototransistor.Importantly,the phototransistor exhibits decent responsivity even under ultra-weak light power of 43μW·cm^(-2) to 1020 nm.This work represents a highly effective and general strategy for fabricating efficient and sensitive SWIR light photodetectors.

Recent advances in long-persistent luminescence materials based on host–guest architecture

Organic long-persistent luminescence(LPL)materials,featuring low preparation cost,eco-friendly synthesis,and easy modification of functional groups,have exhibited extensive applications in information encryption,anti-counterfeiting,and biological imaging.Several design strategies including crystallization-inducement,H-aggregation,and host-guest doping to enhance persistent-room-temperature phosphorescence(RTP)effect by precisely controlling intersystem crossing(ISC)constant and suppressing nonradiative decay rates,those are important strategies to enable LPL performance.Among the strategies,researchers have made several efforts to enhance persistent-RTP effect by host-guest interaction,in which the host matrices provide a rigid environment for phosphor guest molecules.The interaction of the luminescent guest molecules with the host matrix can effectively reduce the vibration and rotation of the luminescent molecules,and suppress the non-radiative inactivation,thereby improving the phosphorescence quantum yield.This review aims to summarize several design strategies of pure organic LPL materials based on persistent-RTP effect through host-guest interaction,and describe some applications of pure organic LPL materials in different fields.

Interfacial molecular screening of polyimide dielectric towards high-performance organic field-effect transistors

The compatibility of the gate dielectrics with semiconductors is vital for constructing efficient conducting channel for high charge transport.However,it is still a highly challenging mission to clearly clarify the relationship between the dielectric layers and the chemical structure of semiconductors,especially vacuum-deposited small molecules.Here,interfacial molecular screening of polyimide(Kapton)dielectric in organic field-effect transistors(OFETs)is comprehensively studied.It is found that the semiconducting small molecules with alkyl side chains prefer to form a high-quality charge transport layer on polyimide(PI)dielectrics compared with the molecules without alkyl side chains.On this basis,the fabricated transistors could reach the mobility of 1.2 cm^(2) V^(−1)s^(−1) the molecule with alkyl side chains on bare PI dielectric.What is more,the compatible semiconductor and dielectric would further produce a low activation energy(E_(A))of 3.01 meV towards efficient charge transport even at low temperature(e.g.,100 K,0.9 cm^(2) V^(−1)s^(−1)).Our research provides a guiding scheme for the construction of high-performance thin-film field-effect transistors based on PI dielectric layer at room and low temperatures.

Highly crystalline,highly stable n-type ultrathin crystalline films enabled by solution blending strategy toward organic single-crystal electronics

The development of n-type semiconductor is still far behind that of p-type semiconductor on account of the challenges in enhancing carrier mobility and environmental stability.Herein,by blending with the polymers,n-type ultrathin crystalline thin film was successfully prepared by the method of meniscus-guided coating.Remarkably,the n-type crystalline films exhibit ultrathin thickness as low as 5 nm and excellent mobility of 1.58 cm^(2) V^(-1) s^(-1),which is outstanding in currently reported organic n-type transistors.Moreover,the PS layer provides a high-quality interface with ultralow defect which has strong resistance to external interference with excellent long-term stability,paving the way for the application of n-type transistors in logic circuits.

Highly emissive white single-molecular material towards organic light-emitting transistors

Organic light-emitting transistors(OLETs)are miniaturized electroluminescent devices,and they simultaneously integrate the dual functionality of switching in organicfield-effect transistors and emission in organic light-emitting diodes,which have recently aroused interest from scientists for the next-generation of display applications[1–3].Notably,white organic light-emitting transistors(WOLETs)have gained much attention for their potential applications in sensors,switches,and light sources,including indoor lighting,street lighting andflood lighting[4].Moreover,the Commission Internationale de l’Elcairage(CIE)standard coordinates are precisely defined as(0.33,0.33)of pure white emission,providing a universal reference for evaluating white light accuracy and consistency across lighting and display technologies[5].To meet the requirements of high color-purity,most of the reported white emissive materials and WOLETs have been achieved by rational combination of red,green,blue for three primary colors or blue and orange for two complementary colors emitters[6],such as doping an emitter into an appropriate host and employing the multi-component active layers with a stacked configuration[7].Although a minority of doped electroluminescent devices have the capability of good exciton utilization to realize the white emission,the multi-component active layer is inherently prone to phase separation,which is harmful for the optoelectronic devices[4].Therefore.

Two-Dimensional Conductive Metal-Organic Framework Reinforced Spinterface in Organic Spin Valves

Interface engineering in device fabrication is a significant but complicated issue.Although great successes have been achieved by conventional physical in situ or ex situ methods,it still suffers from complicated procedures.In this work,we present a facile method for fabricating phthalocyanine(Pc)-based two-dimensional conductive metal–organic framework(MOF)films.Based on PcM-Cu(M=Ni,Cu,H_(2))MOF films,spin valves with a vertical configuration of La_(0.67)Sr_(0.33)MnO_(3)/PcM-Cu MOFs/Co were constructed successfully,and exhibited notably high negative magnetoresistance(MR)up to -22% at 50 K.The penetrated Co atoms coordinated with the dehydrogenated hydroxy groups in the MOFs resulting in an antiferromagnetic layer of the PcM-Cu-Co hybrid structure.Interestingly,a significant exchange bias effect was demonstrated at the PcM-Cu MOF/Co interface,beneficial for the MR behavior.Thus,our present study provides new insights into developing high-performance organic spin valves via de novo molecular design.

Special issue dedicated to Professor Daoben Zhu on the occasion of his 80th birthday

This special issue is dedicated to Professor Daoben Zhu on the occasion of his 80th birthday and in recognition of his prominent contributions to the interdisciplinary fi eld of molecular materials and devices.Professor Zhu was born in Shanghai in 1942.He fi nished his graduate courses at East China University of Science and Technology in 1968.He joined the Institute of Chemistry,Chinese Academy of Sciences(ICCAS)as an assistant professor,and was promoted to associate professor in 1985 and professor in 1987.He worked as a visiting scholar from 1977 to 1979 and a visiting scientist from 1985 to 1986 at the Max-Planck Institute for Medical Research in Heidelberg,Germany.

Chemical vapor deposition for few‐layer two‐dimensional materials

Chemical vapor deposition(CVD)approach offers a controllable strategy for preparing large‐area and high‐quality few‐layer(mainly bilayer or trilayer)twisted or untwisted two‐dimensional(2D)materials,and is predicted to boost the development of 2D materials from laboratory research to industrial applications.

Cocrystal engineering:towards high-performance near-infrared organic phototransistors based on donor-acceptor charge transfer cocrystals

Near-infrared organic phototransistors have wide application prospects in many fields.The active materials with the high mobility and near-infrared response are critical to building high-performance near-infrared organic phototransistors,which are scarce at present.Herein,a new charge transfer cocrystal using 5,7-dihydroindolo[2,3-b]carbazole(5,7-ICZ)as the donor and 2,2’-(benzo[1,2-b:4,5-b’]dithiophene-4,8-diylidene)dimalononitrile(DTTCNQ)as the acceptor is properly designed and prepared in a stoichiometric ratio(D:A=1:1),which not only displays a high electron mobility of 0.15 cm^(2)V^(-1)s^(-1) and very low dark current,but also can serve as the active layer materials in the region of near-infrared detection due to the narrowed band gap and good charge transport properties.A high photosensitivity of 1.8×10^(4),the ultrahigh photoresponsivity of 2,923 A W-1and the high detectivity of 4.26×10^(11)Jones of the organic near-infrared phototransistors are obtained.

Largeπ-conjugated indium-based metal-organic frameworks for high‐performance electrochemical conversion of CO_(2)

The active site engineering of electrocatalysts,as one of the most economical and technological approaches,is a promising strategy to enhance the intrinsic activity and selectivity towards electrochemical CO_(2)reduction reaction.Herein,an indium-based porphyrin framework(In-TCPP)with a well-defined structure,highly dispersed catalytic center,and good stability was constructed for efficient CO_(2)-to-formate conversion.In-TCPP could achieve a high Faraday efficiency for formate(90%)and a cathodic energy efficiency of 63.8%in flow cells.In situ attenuated total reflectance Fourier transform infrared spectroscopy and density functional theory calculation confirm that the crucial intermediate is*COOH species which contributes to the formation of formate.This work is expected to provide novel insights into the precise design of active sites for high-performance electrocatalysts towards electrochemical CO_(2)reduction reaction.