Genetic dissection and validation of a major QTL for grain weight on chromosome 3B in bread wheat(Triticum aestivum L.)

Grain weight is one of the key components of wheat(Triticum aestivum L.)yield.Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(RIL)population derived from a cross between W7268 and Chuanyu 12(CY12)was employed to detect quantitative trait loci(QTLs)for thousand-grain weight(TGW),grain length(GL),grain width(GW),and the ratio of grain length to width(GLW)in six environments.Seven major QTLs,QGl.cib-2D,QGw.cib-2D,QGw.cib-3B,QGw.cib-4B.1,QGlw.cib-2D.1,QTgw.cib-2D.1 and QTgw.cib-3B.1,were consistently identified in at least four environments and the best linear unbiased estimation(BLUE)datasets,and they explained 2.61 to 34.85%of the phenotypic variance.Significant interactions were detected between the two major TGW QTLs and three major GW loci.In addition,QTgw.cib-3B.1 and QGw.cib-3B were co-located,and the improved TGW at this locus was contributed by GW.Unlike other loci,QTgw.cib-3B.1/QGw.cib-3B had no effect on grain number per spike(GNS).They were further validated in advanced lines using Kompetitive Allele Specific PCR(KASP)markers,and a comparison analysis indicated that QTgw.cib-3B.1/QGw.cib-3B is likely a novel locus.Six haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and cultivars.According to gene annotation,spatial expression patterns,ortholog analysis and sequence variation,the candidate gene of QTgw.cib-3B.1/QGw.cib-3B was predicted.Collectively,the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.

Identification and validation of major QTL for grain size and weight in bread wheat(Triticum aestivum L.)

Grain size and weight are key components of wheat yield.Exploitation of major underlying quantitative trait loci(QTL)can improve yield potential in wheat breeding.A recombinant inbred line(RIL)population was constructed to detect QTL for thousand-grain weight(TGW),grain length(GL)and grain width(GW)across eight environments.Genomic regions associated with grain size and grain weight were identified on chromosomes 4A and 6A using bulked segregant exome sequencing(BSE-Seq)analysis.After constructing genetic maps,six major QTL detected in at least four individual environments and in best linear unbiased estimator(BLUE)datasets,explained 7.50%-23.45%of the phenotypic variation.Except for QGl.cib-4A,the other five QTL were co-located in two regions,namely QTgw/Gw.cib-4A and QTgw/Gw/Gl.cib-6A.Interactions of these QTL were analyzed.Unlike QTgw/Gw/Gl.cib-6A,QTgw/Gw.cib-4A and QGl.cib-4A had no effect on grain number per spike(GNS).The QTL were validated in a second cross using Kompetitive Allele Specific PCR(KASP)markers.Since QTgw/Gw.cib-4A was probably a novel locus,it and the KASP markers reported here can be used in wheat breeding.TraesCS4A03G0191200 was predicted to be potential candidate gene for QTgw/Gw.cib-4A based on the sequence differences,spatiotemporal expression patterns,gene annotation and haplotype analysis.Our findings will be useful for fine mapping and for marker-assisted selection in wheat grain yield improvement.

Advertisement Call Variability in the Black-spined Toad Bufo melanostictus (Anura: Bufonidae) during the Breeding Season in Lishui, Zhejiang, China

Advertisement calls play an important role in influencing female mate choice and are regarded as one of the key characters responsible for reproductive isolation and speciation events in frogs and toads. The black-spined toad, Bufo melanostictus, is one of the most common amphibians in Southeast Asia and is frequently observed in human habitations throughout its distributional range. The advertisement calls of the toad have not been well described. Here, we report the advertisement calls of this species from Lishui, Zhejiang, China during its breeding season. The advertisement calls of B. melanostictus are composed of single notes with a single harmonic frequency emitted sporadically. The call parameters recorded in this study were highly variable across recording times and with different body sizes. Dominant frequency was negatively correlated with body size. Comparing the calls of the B. melanostictus population from Lishui with the populations from five other localities(Bangkok, Thailand; Coorg, India; Burma, Myanmar; Bali, Indonesia; Halimun-Salak National Park, Indonesia), we found that call structure was similar among five different populations with no harmonics, while the Halimun-Salak National Park population contained two clear harmonics. Dominant frequency was similar between Bali(1.56 kHz) and Coorg(1.6 kHz) populations, while it was highly variable among other populations. Besides call duration, call interval and pulse/call rate may also be significantly different among the comparing populations. Pooling the available data, we observed some similarities and differences in call parameters among the six populations.

DID Code:A Bridge Connecting the Materials Genome Engineering Database w让h Inheritable Integrated Intelligent Manufacturing

A data identifier(DID)is an essential tag or label in all kinds of databases—particularly those related to integrated computational materials engineering(ICME),inheritable integrated intelligent manufacturing(I3M),and the Industrial Internet ofThings.With the guidance and quick acceleration of the developme nt of advanced materials,as envisioned by official documents worldwide,more investigations are required to construct relative numerical standards for material informatics.This work proposes a universal DID format consisting of a set of build chains,which aligns with the classical form of identifier in both international and national standards,such as ISO/IEC 29168-1:2000,GB/T 27766-2011,GA/T 543.2-2011,GM/T 0006-2012,GJB 7365-2011,SL 325-2014,SL 607-201&WS 363.2-2011,and QX/T 39-2005.Each build chain is made up of capital letters and numbers,with no symbols.Moreover,the total length of each build chain is not restricted,which follows the formation of the Universal Coded Character Set in the international standard of ISO/IEC 10646.Based on these rules,the proposed DID is flexible and convenient for extendi ng and sharing in and between various cloud-based platforms.Accordingly,classical two-dimensional(2D)codes,including the Hanxin Code,Lots Perception Matrix(LP)Code,Quick Response(Q.R)code,Grid Matrix(GM)code,and Data Matrix(DM)Code,can be constructed and precisely recognized and/or decoded by either smart phones or specific machines.By utilizing these 2D codes as the fingerprints of a set of data linked with cloud-based platforms,progress and updates in the composition-processing-structure-property-performance workflow process can be tracked spontaneously,paving a path to accelerate the discovery and manufacture of advanced materials and enhance research productivity,performance,and collaboration.

Effects of Predation by Invasive Western Mosquitofish(Gambusia affinis) on Survival of Eggs,Embryos and Tadpoles of Pelophylax nigromaculatus and Duttaphrynus melanostictus in South China

Alien species are one of the most serious threats to the decline and extinction of native amphibian populations. In this study, we examined the predation of invasive Western Mosquitofish Gambusia affinis on the eggs, embryos, and tadpoles of Duttaphrynus melanostictus and Pelophylax nigromaculatus in south China. Our results suggested that the survival of eggs and embryos remaining in the egg capsules of P. nigromaculatus and D. melanostictus was significantly higher than those removed from the egg capsule at 12-h intervals within 72 h in the presence of G. affinis. The survival of P. nigromaculatus eggs and embryos without egg capsules was significantly lower than those of D. melanostictus without egg capsules. The survival of P. nigromaculatus eggs and embryos with egg capsules was significantly higher than those of D. melanostictus with egg capsules from 24 h to 72 h except for 12 h. The survival of D. melanostictus tadpoles was significantly higher than that of P. nigromaculatus tadpoles in the presence of G. affinis. The survival of Gosner stage 26 tadpoles of P. nigromaculatus was significantly higher than that of Gosner stage 30 tadpoles from 12 h to 60 h, but there were no significant differences at 72 h. In contrast, the survival of Gosner stage 26 tadpoles of D. melanostictus was significantly lower than that of Gosner stage 30 tadpoles within 72 h, recording every 12 h. The increasing temperature caused a significant increase in predation by G. affinis on P. nigromaculatus eggs and embryos. The outer jelly capsule surrounding anurans eggs might serve as a mechanical defense against predation by G. affinis due to its large diameter, relatively stationary state and unpalatability. The differences in the vulnerability of P. nigromaculatus and D. melanostictus embryos and tadpoles to G. affinis probably due to differences in the unpalatability, black skin and activity. Based on the magnitude of predation by G. affinis on the eggs, embryos and tadpoles of these two species and the combined impact of temperature, we might speculate that invasive G. affinis and global warming would have more detrimental impacts on population viability of P. nigromaculatus than D. melanostictus in China.

Density But Not Kinship Regulates the Growth and Developmental Traits of Chinese Tiger Frog (Hoplobatrachus chinensis) Tadpoles

Kinship and density are believed to affect important ecological processes such as intraspecific competition, predation, growth, development, cannibalism, habitat selection and mate choice, In this work, we used Chinese tiger frog Hoplobatrachus chinensis tadpoles as an experimental model to investigate the effects of kinship and density on growth and development of this species over a 73 day period. The results showed that density can affect the growth and developmental traits （survival rate, larval period, size at the limb bud protrusion/metamorphic climax and body mass at different life stages） of H. chinensis tadpoles, while kinship does not. Tadpoles took longer to develop and potential metamorphosis was greater in high density groups of both sibling and non-siblings. The interaction of kinship and density did not significantly influenced growth traits of H. chinensis tadpoles during the experimental period. For coefficient variations of each growth trait, no differences were detected between sibling and non-sibling groups. These findings provide valuable information on the basic ecology of H. chinensis which will be helpful in future studies of other anuran species.

高分子降解课程思政教学探索与实践

在高分子降解课程中紧密结合课程内容,围绕高分子降解中的“卡脖子难题”“科学家故事”“工程伦理”等方面深入挖掘课程思政素材,通过“主题式”课程大作业汇报、“模拟联合国”等形式开展丰富多样的课程思政教学,培养学生“科技报国”“科学发展观”“科学精神”和全球胜任力。

合理优化实验教学资源 有效提升化学科学素养

初中化学的学习目的是学习化学的基本概念和基本原理;学习一些化学实验和化学计算的基本技能;初步认识化学在实际生活中的应用;培养科学的学习方法,及关心社会、关心自然的情感,提升化学学科素养。文章就在教学实践中,如何优化化学实验教学资源,扬长避短,合理运用两种实验教学资源的互补性,有效提升化学科学素养,进行初步探讨和研究。

调整教学内容 重组教学顺序——以初中化学为例

对于酸碱盐的化学性质的考查,在各省中考试卷命题中无不作为重中之重。其题型之多,变化之大,一直是化学教学中的重难点。酸碱盐部分虽然题型众多,但都是以酸碱盐知识为载体。科粤版教材没有根据电离来定义酸碱盐,而是进行弹性处理、打"擦边球",采取实例描述的方法介绍酸碱盐,在实际教学中效果不佳。为了加强学生的认知参与,行为参与,在教学实践中,尝试对初中化学第八章第二节的教学内容进行调整和重组,以提高学生的学习兴趣,提高教学效率。

Expression of cytochrome P450 2A13 in human non-small cell lung cancer and its clinical significance

Lung cancer is one of the most important causes of cancer-related mortality worldwide. Human cytochrome P450 2A13 enzyme （CYP2A13） is predominantly expressed in the respiratory tract and could catalyze various carcinogens. In this study, we quantified CYP2A13 expression in non-small cell lung cancer （NSCLC） tissues and examined the relation between CYP2A13 and clinicopathologic factors. Thirty-five paired lung cancer and normal tissues were studied for the expression of the CYP2A13 gene by using real-time PCR and Western blot- ting assays. We also investigated the relationship between CYP2A13 expression and clinicopathologic factors such as age, gender, histology and lymph node status in tumor tissues. SPSS （17.0） statistical software was applied for data analysis. The real-time PCR results showed that there was no significant difference in the CYP2A13 mRNA transcript levels between tumor and paired normal tissues in the 35 samples and in 12 paired squamous cell car- cinomas. In adenocarcinoma, the expression of CYP2A13 mRNA in tumor tissues was 12.5% of that in adjacent tissues （P 〈 0.05） and it was not associated with age, gender, histology and lymph node status of the patients. The amounts of CYP2A13 proteins detected by Western blotting assays correlated well with those of the correspond- ing mRNAs. In conclusion, the expression of CYP2A13 was downregulated in lung adenocarcinoma. CYP2A13 may be involved in the development and progression of lung adenocarcinoma.

Effects of electrostimulation and administration of succinylcholine on the expression of Fos protein in mesencephalic periaqueductal gray matter of rats after simulated weightlessness

BACKGROUND： Expression of Fos in neurons of periaqueductal gray （PAG） is used to reflect the excitability. However, changes of expression of Fos in neurons of PAG are caused by injured electrostimulation after simulated weightlessness, and the relationship between pretreatment and injection of succinylcholine has not been determined yet. OBJECTIVE ： To investigate the changes of expression of Fos in PAG induced by injured electrostimulation pretreatment and injection of succinylcholine at 2 weeks after simulated weightlessness.DESIGN： Observational and controlled animal study.SETTING： Department of Physiology, Medical School, Xi＇an Jiaotong University; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education. MATERIALS： A total of 24 adult female SD rats, of clean grade and weighing 180-220 g, were selected in this study. METHODS： The experiment was completed in the Experimental Animal Center of Xi＇an Jiaotong University.① All rats were randomly divided into 2 groups according to body mass： simulated weightlessness group and control group with 12 in each group. And then, each group was also divided into 3 subgroups： electrostimulation group, succinylcholine-pretreatment group and succinylcholine-injection group with 4 in each subgroup. ②The model of weightlessness was simulated by tail-suspended female rats, which were described and modified by Cheng Jie. Rats in normal control group were given the same interventions as simulated weightlessness group except for tail-suspended. ③ Experimental method： The rats in electrostimulation group were given nociceptive stimulus by a pair of subcutaneous electrodes inserted into 1 and 5 claw of left hindlimb. The stimulus （current： 10 mA; duration： 1 ms; interval： 1 s） lasted for 30 minutes. The rats in succinylcholine-pretreatment group received stimulus after intravenous administration of succinylcholine, rats in succinylcholine-injection group were not given stimulus, just received succinylcholine. ④ All rats were perfused and fixed after 2 hours from the end of stimulation. The brains were removed, and serial frozen sections of midbrain were stained using immunocytochemical method, observed and taken photos under light-microscope. The number and morphological characters of Fos-immunoreactive （Fos-IR） neurons in ventrolateral part of PAG were investigated. MAIN OUTCOME MEASURES： The alterations in number and morphological characters of Fos-IR neurons in ventrolateral PAG of all rats.RESULTS： A total of 24 rats were involved in the final analysis. ① The morphological changes of Fos-IR neurons： The expressions of Fos in ventrolateral part of PAG were observed in both control and simulated weightlessness groups rats after being given nociceptive stimulus. As compared with control group, Fos-IR neurons in simulated weightlessness group were dyed lightly, cellular integrity was impaired, and cellular verge was unclear. ② The numbers of Fos-IR neurons： In control group, the numbers of Fos-IR neurons in ventrolateral part of PAG in simulated weightlessness group were obviously lower than succinylcholine-pretreatment group, but obviously higher than succinylcholine-injection group （46.94±3.38, 71.06±8.96 and 35.04±4.62, respectively, P 〈 0.05）. In 14-day simulated weightlessness group, the numbers of Fos-IR neurons in electrostimulation group were also obviously lower than succinylcholine-pretreatment group, and obviously higher than succinylcholine-injection group （27.77±3.27, 32.91±2.99 and 11.75±1.00, respectively, P 〈 0.05）. The numbers of Fos-IR neurons in all subgroups in control group were obviously higher than those subgroups in simulated weightlessness group. Compared with electrostimulation group, the percentage of expression of Fos in ventrolateral part of PAG responsed to nociceptive stimulus after administration of succinylcholine （SCH） was increased to 51.83% in control group and 18.51% in simulated weightlessness group.CONCLUSION ：① The expression of Fos in neurons in ventrolateral part of PAG were increased by the pretreatment of SCH before nociceptive stimulus.② Nociceptive stimulus could increase the expression of Fos in neurons in ventrolateral part of PAG. ③ The numbers of Fos-IR neurons in ventrolateral part of PAG were decreased obviously after 2-week simulated weightlessness.

Sexual differences of the effects of prenatal stress on the expression of extracellular signal-regulated kinaseas in the hippocampus of offspring rats

BACKGROUND： Prenatal stress has been shown to inhibit cell proliferation in the dentate gyrus and hippocampus, reduce hippocampal volume, and cause neuronal loss and oxidative damage in the hippocampus of offspring rats, but the sexual difference of the effects on offsprings is seldom referred to. OBJECTIVE： To observe the effect of prenatal stress to adult pregnant rats on expression of extracellular signal-regulated kinases （ERK） in hippocampus of the offspring rats of different genders. DESIGN ： A randomized and control animal experiment.SETTING： Department of Physiology and Pathophysiology, School of Medicine, Xi＇an Jiaotong University. MATERIALS ： The experiments were carried out in the Key Laboratory of Environment and Gene Related Diseases （Xi＇an Jiaotong University）, Ministry of Education between October 2005 and March 2006. Fifteen female and five male adult Sprague-Dawley rats were adopted. Female rats weighing 230-250 g and male rats weighing 280-350 g were used. METHODS： The virgin female rats were placed overnight with adult male rats （3：1） for mating. A total of twelve pregnant rats were randomly assigned to prenatal stress group （PNS group, n=6） and control group （n=6）. The pregnant rats of the PNS group were exposed to restraint stress on days 14-20 of pregnancy three times a day, 45 minutes for each time . The restraint device was a transparent plastic tube （6.8 cm in diameter） with air holes for breathing and closed end. The length could be adjusted to accommodate the size of the animals. To prevent habituation of animals to the daily procedure, restraint periods were randomly shifted within certain time periods （8：00-11：00, 11：00-14：00, and 16：00-19：00）. After birth, offsprings of all groups were culled to 8-10 litters in each group and housed in the same animal room, and kept together with their biologic mothers. The pregnant rats of the control group were left undisturbed. On day 21, after all the offspring were weaned, male and female pups were separated and housed four in each cage respectively until test at 30 days of age. At the end of postnatal day 30, one male and female offspring rats from the same dam were selected with a random choice and a total of 24 animals from 12 different dams were used. The experimental rats were sacrificed by decapitation under anesthesia. Bilateral hippocampal tissues were isolated and homogenized in cold condition. Alkaline carbonate buffer （BCA） method was used to detect the concentration of extracellular signal-regulated kinases （ERK）, then mixed with loading buffer, the constant voltage was 100 V. Finally, BCIP/NBT staining and electrDphoresis were performed, the absorbance （A） value for the bands was detected with the Bandscan analytical software, and the expression of ERK in hippocampus of offspring rats of different genders in each group was quantitatively analyzed. MAIN OUTCOME MEASURES： The level of ERK expression in hippocampus of offspring rats of different genders in each group was observed.RESULTS： All the 24 offspring rats were involved in the analysis of results. ① The staining results of ERP activity in the extract of brain tissue detected with Western blotting technique and specific antibody analysis showed that the ERP in hippocampus of offspring rats had two subtypes of ERK-1 and ERK-2, and the latter was the main type.② Standardized by the average A value in the control group, the quantitative data of the general A value of total ERK showed that the expression of ERK-2 in hippocampus of female offspring rats was obviously higher in the PNS group than in the control group （A value： 126±6.76,100±4.89,P〈 0.01）. ③The expression of ERK-2 had no obvious difference between the female and male offspring rats in the control group.④ The expression of ERK-2 in hippocampus of male offspring rats was a little higher in the PNS group than in the control group （A value： 104±6.27,102±5.48,P 〉 0.05）. CONCLUSION ： PNS significantly affects the increase of ERK expression in hippocampus of female offspring rats, but has no obvious influence on that of male ones.

鸟鸣多样性感知与声景感知恢复性:鸟鸣音频和科普的干预

自然声景具有感知恢复性,让人从疲劳中恢复,鸟鸣是声景中的重要组成,研究鸟鸣对声景感知恢复性的影响,可以为公众从自然中获得更高水平的感知恢复性效益提供参考依据。2021年7–8月,我们在北京西山国家森林公园使用播放鸟鸣的扬声器增加环境中的鸟鸣多样性,设置标识牌以提供当地常见鸟类及鸟鸣的科普信息,并对744名游客进行问卷调查,了解游客获得的声景感知恢复性和对鸟鸣多样性的感知水平。研究发现处在鸟鸣多样性更丰富环境的游客获得了更高水平的声景感知恢复性效益,获得鸟鸣科普信息的游客感知到了更高水平的鸟鸣多样性,游客感知的鸟鸣多样性与实际鸟鸣多样性不相关。结果表明声景恢复性与环境中鸟鸣多样性呈正相关,更丰富的鸟鸣多样性能够改善游客在自然环境中的游览体验并受益,标识牌能够促进游客关注环境,提高感知到的鸟鸣数量。

Structural superlubricity at homogenous interface of pentagraphene

Two-dimensional(2D)van der Waals layered materials have been widely used as lubricant.Penta-graphene(PG),a 2D carbon allotrope exclusively composed of irregular carbon pentagons has recently been predicted to have superlubricating property.In the present study,by combining the molecular dynamics simulation and first-principles calculations,we investigated the frictional property of PG in both commensurate and incommensurate contacts.Our calculations show the ultra-low friction at the interface of relatively rotated bilayer PG with twist angles of more than 10°away from the commensurate configuration.Meanwhile,our calculations demonstrate the isotropy of the ultra-low friction at the interface of incommensurate contact,in contrast to the anisotropic of the commensurate contacting interface.Additionally,the evolution of friction force and the fluctuation of potential energy along sliding path correlate closely with the interface’s structure.The energetics and charge density explain the difference between the friction at the interfaces of the commensurate and incommensurate contacts.Not only that,we found the correlation between the intrinsic structural feature and interlayer binding energy.Importantly,our findings on the retainment of the ultra-low friction under work conditions indicates that the superlubricating state of PG has good practical adaptability.

Boundary slip and lubrication mechanisms of organic friction modifiers with effect of surface moisture

Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a combination of molecular dynamics(MD)simulation and experiment for the organic friction modifier(OFM)-containing lubricant.The stearic acid and poly-α-olefin 4cSt(PAO4)were chosen as the OFM and base oil molecules,respectively.The physical adsorption indicates that on the moist surface water molecules are preferentially adsorbed on friction surface,and even make OFM adsorption film thoroughly leave surface and mix with base oil.In shear process,the adsorption of water film and desorption OFM film are further enhanced,particularly under higher shear rate.The simulated friction coefficient(that is proportional to shear rate)increases firstly and then decreases with thickening water film,in good agreement with experiments,while the slip length shows a contrary change.The wear increases with humidity due to tribochemistry revealing the continuous formation and removal of Si–O–Si network.The tribological discrepancy of OFM-containing lubricant in dry and humid conditions is attributed to the slip plane’s transformation from the interface between OFM adsorption film and lubricant bulk to the interface between adsorbed water films.This work provides a new thought to understand the boundary lubrication and failure of lubricant in humid environments,likely water is not always harmful in oil lubrication systems.

PBO fibers/fluorine-containing liquid crystal compound modified cyanate ester wave-transparent laminated composites with excellent mechanical and flame retardance properties

Bisphenol A dicyanate ester resins modified by fluorine-containing liquid crystal compound(LCFE)are applied as polymer matrix(LCFE-BADCy),poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers as rein-forcements,and fluorine/adamantane PBO precursor(pre FABPBO)as interfacial compatibilizer to prepare the corresponding PBO fibers/FABPBO/LCFE-BADCy wave-transparent laminated composites.LCFE could improve the order degree of BADCy cured network,in favor of enhancing the wave-transparent perfor-mance,mechanical properties,and intrinsic thermal conductivity.The dielectric constant and dielectric loss of PBO fibers/FABPBO/LCFE-BADCy composites are highly temperature(25–200℃)and frequency(10^(4)–10^(7) Hz and 8.2–12.4 GHz)stable with the value of 2.49 and 0.003 under 10^(6) Hz at 25℃,and the corresponding wave transmission efficiency is 95.0%,higher than that of 92.5%for PBO fibers/BADCy com-posites.The interlamellar shear strength and flexural strength are respectively 50.7 MPa and 682.5 MPa,38.1%and 16.2%higher than those of PBO fibers/BADCy composites.Besides,the volume resistivity,breakdown voltage,heat resistance index,glass transition temperature,flame retardant grade,and ul-timate oxygen index of PBO fibers/FABPBO/LCFE-BADCy composites are respectively 5.3×10^(15)Ωcm,29.75 kV/mm,217.2℃,245.7℃,V-1 grade,and 33.6%,expected to be performed as a new generation of“lightweight/loading/wave-transparent”electromagnetic window materials in advanced military weapons and civil communication base station.

Branched Fluorine/Adamantane Interfacial Compatibilizer for PBO Fibers/Cyanate Ester Wave-Transparent Laminated Composites

Comprehensive Summary Branched fluorine/adamantane PBO precursor(preFABPBO),synthesized via random co-condensation between 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoro propane,1,3-adamantanedicarbonyl dichloride,and trimesoyl chloride,is performed as interfacial compatibilizer,bisphenol A dicyanate ester(BADCy)resin as polymer matrix,and poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers as reinforcements to prepare PBO fibers/FABPBO-BADCy wave-transparent laminated composites by high temperature molding.The mechanical properties,wave-transparent performances,and heat resistances of PBO fibers/BADCy composites are simultaneously improved by the addition of preFABPBO.The interlaminar shear strength(ILSS)and flexural strength of PBO fibers/FABPBO-BADCy composites are 48.9 and 665.3 MPa,respectively,increased by 33.2%and 13.3%compared to those of PBO fibers/BADCy composites(36.7 and 587.4 MPa).The dielectric constant and dielectric loss values at 106 Hz are 2.53 and 0.003,respectively,lower than those of PBO fibers/BADCy composites(3.06 and 0.006),and the corresponding wave transmission efficiency is 94.8%,which also presents excellent stability over the wide temperature(25-200℃)and frequency range(103-107 Hz and 8.2-12.4 GHz).Meanwhile,the heat resistance index and glass transition temperature are 229.9℃and 247.5℃,also better than those of PBO fibers/BADCy composites(229.6℃and 247.1℃).

Factors and cytokine signatures associated with the response to therapy in patients with primary biliary cholangitis-autoimmune hepatitis overlap syndrome:a real-world study

To the Editor:Autoimmune liver disease is a chronic immune-mediated liver disease.The term“overlap syndrome”(OS)is used to describe the conditions in which patients simultaneously or consecutively present with features of primary biliary cholangitis(PBC)or primary sclerosing cholangitis and autoimmune hepatitis(AIH).[1]PBC-AIH OS is described most frequently,[2]with a prevalence of approximately 8%to 20%in adult patients with either pure PBC or AIH.

Application of metal-organic frameworks,covalent organic frameworks and their derivates for the metal-air batteries

Metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)as the novel porous materials have the merits of diverse,adjustable functionality,high porosity and surface area,which have great application prospects in the gas storage,separation and catalysis.In addition,their derivates make up for the insufficient of electronic conductivity and chemical stability of MOFs and COFs,and provide a new ideal for accurate control of material structure.Up to now,many efficient electrocatalysts have been designed based on MOFs,COFs and their derivates for O_(2)reduction/evolution reactions(ORR/OER)and CO_(2)reduction/evolution reactions(CO_(2)RR/CO_(2)ER)in the metal-air batteries.In this review,the latest development of MOFs,COFs and their derivates in the metal-air batteries is summarized,and we discuss the structural characteristics of these materials and their corresponding mechanisms of action.By comprehensively reviewing the advantages,challenges and prospects of MOFs and COFs,we hope that the organic framework materials will shed more profound insights into the development of electrocatalysis and energy storage in the future.

Polysilsesquioxane‑PBO Wave‑Transparent Composite Paper with Excellent Mechanical Properties and Ultraviolet Aging Resistance

The rapid development of radar antenna systems to meet requirements for high integration and precision places stringent requirements on the dielectric properties,mechanical properties and heat resistance of wave-transparent composite paper.In this paper,poly(p-phenylene-2,6-benzobisoxazole)(PBO)fibers are first dissolved by trifluoroacetic acid/methyl sulfonic acid to obtain PBO nanofibers(PNF),and the amino polysilsesquioxane(NH_(2)-POSS)is dispersed uniformly inside the PNF via ultrasonic-assisted and deprotonation.The POSS-PNF composite paper is fabricated by the method of“suction filtration and hot-pressing”.Because of the uniformly dispersion of NH_(2)-POSS,the POSS-PNF composite paper has a low dielectric constant(ε,2.08)and dielectric loss tangent(tanδ,0.0047),and the wave-transparent coefficient(|T|2)is 96.7%(1 MHz),which is higher than that of PNF paper(95.5%,1 MHz).Additionally,the POSS-PNF composite paper possesses excellent tensile strength of 163.3 MPa,tensile modulus of 6.9 GPa,toughness of 9.1 MJ/m^(3),outstanding flame retardancy and excellent UV aging resistance.According to a simulation of the radome honeycomb panel,POSS-PNF composite paper has low loss and reflections of electromagnetic waves in the X-band(8.4~12.4 GHz),and wide angle of incidence(0°-80°),which favor high|T|2.The results indicate that the POSS-PNF composite paper has excellent potential for applications in the fields of aerospace,wearable flexible electronic devices and 5G communication.