Phylotranscriptomic discordance is best explained by incomplete lineage sorting within Allium subgenus Cyathophora and thus hemiplasy accounts for interspecific trait transition

The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and diversification.Much can be learned about this process from phylogeny-based trait evolution.However,such inference is often plagued by genome-wide gene-tree discordance(GTD),mostly due to incomplete lineage sorting(ILS)and/or introgressive hybridization,especially when the genes underlying the traits appear discordant.Here,by collecting transcriptomes,whole chloroplast genomes(cpDNA),and population genetic datasets,we used the coalescent model to turn GTD into a source of information for ILS and employed hemiplasy to explain specific cases of apparent“phylogenetic discordance”between different morphological traits and probable species phylogeny in the Allium subg.Cyathophora.Both concatenation and coalescence methods consistently showed the same phylogenetic topology for species tree inference based on single-copy genes(SCGs),as supported by the KS distribution.However,GTD was high across the genomes of subg.Cyathophora:~27%e38.9%of the SCG trees were in conflict with the species tree.Plasmid and nuclear incongruence was also present.Our coalescent simulations indicated that such GTD was mainly a product of ILS.Our hemiplasy risk factor calculations supported that random fixation of ancient polymorphisms in different populations during successive speciation events along the subg.Cyathophora phylogeny may have caused the character transition,as well as the anomalous cpDNA tree.Our study exemplifies how phylogenetic noise can be transformed into evolutionary information for understanding character state transitions along species phylogenies.

有机化学实验课教学质量提升的探索与实践

本文介绍了有机化学实验教学过程中存在的一些问题,并从强化学生预习效果、加强教师技能培训、重视集体备课、强化实验过程的教师指导、增加课后的评价反思等方面介绍了我校提高有机化学实验教学质量的探索和实践。

Insight into the experiment and extraction mechanism for separating carbazole from anthracene oil with quaternary ammonium-based deep eutectic solvents

Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering.Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil.In this research,three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors.To explore their extraction performance of carbazole,the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution (γ^(∞)) of carbazole in DESs,and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution (C^(∞)) value.Then,the separation performance of these three DESs was evaluated by experiments,and the experimental results were in good agreement with the COSMO-RS prediction results.The TBAC:EG (1:2) was determined as the most promising solvent.Additionally,the extraction conditions of TBAC:EG (1:2) were optimized,and the extraction efficiency,distribution coefficient and selectivity of carbazole could reach up to 85.74%,30.18 and 66.10%,respectively.Moreover,the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent.In addition,the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene,the carbazole was obtained with purity and yield of 85.32%,60.27%,respectively.Lastly,the extraction mechanism was elucidated byσ-profiles and interaction energy analysis.Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H...Cl) and van der Waals interactions (C–H...O and C–H...π),which corresponding to the blue and green isosurfaces in IGMH analysis.This work presented a novel method for separating carbazole from crude anthracene oil,and will provide an important reference for the separation of other high value-added products from coal tar.

Moderate Fields, Maximum Potential: Achieving High Records with Temperature‑Stable Energy Storage in Lead‑Free BNT‑Based Ceramics

The increasing awareness of environmental concerns has prompted a surge in the exploration of leadfree,high-power ceramic capacitors.Ongoing efforts to develop leadfree dielectric ceramics with exceptional energystorage performance(ESP)have predominantly relied on multicomponent composite strategies,often accomplished under ultrahigh electric fields.However,this approach poses challenges in insulation and system downsizing due to the necessary working voltage under such conditions.Despite extensive study,bulk ceramics of(Bi_(0.5)Na_(0.5))TiO_(3)(BNT),a prominent lead-free dielectric ceramic family,have seldom achieved a recoverable energy-storage(ES)density(Wrec)exceeding 7 J cm^(−3).This study introduces a novel approach to attain ceramic capacitors with high ESP under moderate electric fields by regulating permittivity based on a linear dielectric model,enhancing insulation quality,and engineering domain structures through chemical formula optimization.The incorporation of SrTiO_(3)(ST)into the BNT matrix is revealed to reduce the dielectric constant,while the addition of Bi(Mg_(2/3)Nb_(1/3))O_(3)(BMN)aids in maintaining polarization.Additionally,the study elucidates the methodology to achieve high ESP at moderate electric fields ranging from 300 to 500 kV cm^(−1).In our optimized composition,0.5(Bi_(0.5)Na_(0.4)K_(0.1))TiO_(3)–0.5(2/3ST-1/3BMN)(B-0.5SB)ceramics,we achieved a Wrec of 7.19 J cm^(−3) with an efficiency of 93.8%at 460 kV cm^(−1).Impressively,the B-0.5SB ceramics exhibit remarkable thermal stability between 30 and 140℃ under 365 kV cm^(−1),maintaining a Wrec exceeding 5 J cm^(−3).This study not only establishes the B-0.5SB ceramics as promising candidates for ES materials but also demonstrates the feasibility of optimizing ESP by modifying the dielectric constant under specific electric field conditions.Simultaneously,it provides valuable insights for the future design of ceramic capacitors with high ESP under constraints of limited electric field.

Review of Sc microalloying effects in Al-Cu alloys

Artificially controlling the solid-state precipitation in aluminum (Al) alloys is an efficient way to achieve well-performed properties,and the microalloying strategy is the most frequently adopted method for such a purpose.In this paper,recent advances in lengthscale-dependent scandium (Sc) microalloying effects in Al-Cu model alloys are reviewed.In coarse-grained Al-Cu alloys,the Sc-aided Cu/Sc/vacancies complexes that act as heterogeneous nuclei and Sc segregation at the θ′-Al_(2)Cu/matrix interface that reduces interfacial energy contribute significantly to θ′precipitation.By grain size refinement to the fine/ultrafine-grained scale,the strongly bonded Cu/Sc/vacancies complexes inhibit Cu and vacancy diffusing toward grain boundaries,promoting the desired intragranular θ′precipitation.At nanocrystalline scale,the applied high strain producing high-density vacancies results in the formation of a large quantity of (Cu Sc,vacancy)-rich atomic complexes with high thermal stability,outstandingly improving the strength/ductility synergy and preventing the intractable low-temperature precipitation.This review recommends the use of microalloying technology to modify the precipitation behaviors toward better combined mechanical properties and thermal stability in Al alloys.

Total ionizing dose effect modeling method for CMOS digital-integrated circuit

Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was proposed.The digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional area.Each of these three parts was separately modeled.Using the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using VHDL-AMS.In the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area models.Furthermore,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital IC.TID experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose point.This confirms the practicality and accuracy of the proposed modeling method.The TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.

Taxonomic Status of Three Recently Proposed Species of the Genus Kurixalus(Anura,Rhacophoridae),with Discussion on the ZooBank Registrations for Electronical Publication

In the present study,we propose the synonymization of Kurixalus silvaenaias with Kurixalus qionglaiensis.This conclusion is based on morphological examination and phylogenetic analysis of a series of newly collected specimens,as well as the type series of both nomenclatures.The publication dates of the two species were determined according to the related articles of the International Code of Zoological Nomenclature.Of note,the ZooBank registrations for both species are invalid.Consequently,the publication of K.silvaenaias does not qualify as a published work and the correct publication date of K.qionglaiensis should be the date on which it was physically printed.Furthermore,based on the results presented in this study and its original description,the proposal of K.inexpectatus is deemed untenable and should,therefore,be considered a junior synonym of K.idiootocus.We further provide suggestions for the authors,editors,and publishers who are working on taxonomic publications,as well as for ZooBank to improve the registering service.

Lactiplantibacillus plantarum AR113 alleviates microbiota dysbiosis of tongue coating and cerebral ischemia/reperfusion injury in rat

Stroke is one of the leading causes of death and disability worldwide.However,information on stroke-related tongue coating microbiome(TCM)is limited,and whether TCM modulation could benefit for stroke prevention and rehabilitation is unknown.Here,TCM from stroke patients(SP)was characterized using molecular techniques.The occurrence of stroke resulted in TCM dysbiosis with significantly reduced species richness and diversity.The abundance of Prevotella,Leptotrichia,Actinomyces,Alloprevotella,Haemophilus,and TM7_[G-1]were greatly reduced,but common infection Streptococcus and Pseudomonas were remarkably increased.Furthermore,an antioxidative probiotic Lactiplantibacillus plantarum AR113 was used for TCM intervention in stroke rats with cerebral ischemia/reperfusion(I/R).AR113 partly restored I/R induced change of TCM and gut microbiota with significantly improved neurological deficit,relieved histopathologic change,increased activities of antioxidant enzymes,and decreased contents of oxidative stress biomarkers.Moreover,the gene expression of antioxidant-related proteins and apoptosis-related factors heme oxygenase-1(HO-1),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),nuclear factor erythroid 2-related factor 2(Nrf2),NAD(P)H:quinone oxidoreductase-1(NQO-1),and Bcl-2 was significantly increased,but cytochrome C,cleaved caspase-3,and Bax were markedly decreased in the brain by AR113 treatment.The results suggested that AR113 could ameliorate cerebral I/R injury through antioxidation and anti-apoptosis pathways,and AR113 intervention of TCM may have the application potential for stroke prevention and control.

Role of oncogenic long noncoding RNA KCNQ1OT1 in colon cancer

The role of lncRNA KCNQ1 opposite strand/antisense transcript 1(KCNQ1OT1)in colon cancer involves various tumorigenic processes and has been studed widely.However,the mechanism by which it promotes colon cancer remains unclear.Retrovirnl vector pSEB61 was retroftted in established HCT116 siKCN and SW480-siKCN cells to silence KCNQ1 OT1.Cellular proliferation was measured using CCK8 assay,and flow cytometry(FCM)detected cell cydle changes.RNA sequencing(RNA Seq)analysis showed differentially expressed genes(DEGs).Gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were carried out to analyze enriched functions and signaling pathways.RT-qPCR,immunofluorescence,and western blotting were carried out to validate downstream gene expressions.The effects of tumorigenesis were evaluated in BALB/c nude mice by tumor xenografts.Our data revealed that the silencing of KONQ1OT1 in HCT116 and SW480 cells slowed cell growth and decreased the number of cells in the G2/M phase.RNA-Seq analysis showed the data of DEGs enriched in various GO and KEGG pathways such as DNA replication and cell cyde.RT qPCR,immunofluorescence,and western blotting confirmed downstream CCNE2 and PCNA gene expressions.HCT116 siKCN cells signifcantly suppressed tumorigenesis in BALB/c nude mice.Our study suggests that lncRNA KCNQ1OT1 may provide a promising therapeutic strategy for colon cancer.

“考古”陶片中酒类残留的分析检测

通过对陶器中酒类残留的检测分析,介绍了化学技术手段在考古工作中的应用。在实验中,学生通过萃取、抽滤、离心、旋转蒸发等实验步骤提取酒的标志物——有机酸,并对其进行高效液相色谱(HPLC)检测,最后结合陶片的考古背景分析陶片的可能用途。该实验依托于考古化学这一新兴交叉学科,面向化学、考古学等专业的学生开设,有助于学生了解并掌握分析化学中样品分离和制备、液相色谱分析等基本概念与操作,并对考古学的研究内容形成一定认识。

新文科背景下理论与实践相结合的考古化学教学模式探索

在新文科建设背景下,我们将化学和考古学融合构建了理论实践相结合的通识核心课程考古化学,打破了文、理学科壁垒,对学生进行理论知识和实验技能紧密结合的跨学科培养。同时结合开放创新实验、毕业设计,根据学生兴趣和职业发展规划量身打造个性化研究课题,引导学生在应用化学理论知识和实验技能解决考古实际问题的过程中建立化学、考古学紧密结合的综合创新思维,提升学生的科研创新能力,为新型文理复合型人才的培养提供了思路。

LW-AFC,a new formula derived from Liuwei Dihuang decoction,ameliorates behavioral and pathological deterioration via modulating the neuroendocrine-immune abnormalities in PrP-hAβPPswe/PS1^(ΔE9) transgenic mice

OBJECTIVE To investigate the effect of LW-AFC,a new formula of the main active components extracted fromLiuwei Dihuang decoction,on treatment of Alzheimer disease(AD) in mouse models.METHODS After treatment LW-AFC,mice were cognitively evaluated in behavioral experiments.Neuron loss,amyloid-β(Αβ) deposition,and Αβ level were analyzed using Nissl staining,immunofluorescence,and an Alpha LISA assay,respectively.Multiplex bead analysis,a radioimmunoassay,immunochemiluminometry,and an ELISA were used to measure cytokine and hormone levels.Lymphocyte subsets were detected using flow cytometry.RESULTS LW-AFC ameliorated the cognitive impairment observed in APP/PS1 mice,including the impairment of object recognition memory,spatial learning and memory,and active and passive avoidance.In addition,LW-AFC alleviated the neuron loss in the hippocampus,suppressed Αβ deposition in the brain,and reduced the concentration of Aβ1-42 in the hippocampus and plasma of APP/PS1 mice.LW-AFC treatment also significantly decreased the secretion of corticotropin-releasing hormone and gonadotropin-releasing hormone in the hypothalamus,and adrenocorticotropic hormone,luteinizing hormone,and follicle-stimulating hormone in the pituitary.Moreover,LW-AFC increased CD8+CD28+T cells,and reduced CD4^+CD25^+Foxp3^+T cells in the spleen lymphocytes,down-regulated interleukin(IL)-1β,IL-2,IL-6,IL-23,granulocyte-macrophage colony stimulating factor,and tumor necrosis factor-α and-β,and up-regulated IL-4 and granulocyte colony stimulating factor in the plasma of APP/PS1 mice.CONCLUSION LW-AFC ameliorated the behavioral and pathological deterioration of APP/PS1 transgenic micevia the restoration of the NIM network to a greater extent than either memantineor donepezil,which supports the use of LW-AFC as a potential agent for AD therapy.

Effects of LW-AFC,a new formula derived from Liuwei Dihuang decoction,on intestinal microbiome in senescence-accelerated mouse prone 8 strain,a mouse model of Alzheimer disease

OBJECTIVE To investigate the effects of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on gut microbiota and the behavior of learning and memory of SAMP8 mice,a mouse model of Alzheimer Disease(AD),and identify the specific intestinal microbiota correlating with cognitive ability.METHODS Morris-water maze test,novel object recognition test and shuttle-box test were conducted to observe the ability of learning and memory.16S rRNA amplicon sequencing(Illumina,San Diego,CA,USA)was employed to investigate gut microbiota.RESULTS The treatment of LW-AFC improved cognitive impairments of SAMP8 mice,including spatial learning and memory ability,active avoidance response,and object recognition memory capability.Our data indicated that there were significantly 8 increased and 12 decreased operational taxonomic units(OTUs)in the gut microbiota of SAMP8 mice compared with senescence accelerated mouse resistant 1(SAMR1) strains,the control of SAMP8 mice.The treatment of LW-AFC altered 22(16 increased and 6 decreased)OTUs in SAMP8 mice and among them,15 OTUs could be reversed by LW-AFC treatment resulting in a microbial composition similar to that of SAMR1 mice.We further showed that there were7(3 negative and 4 positive correlation)OTUs significantly correlated with all the three types of cognitive abilities,at the order level,including Bacteroidales,Clostridiales,Desulfovibrionales,CW040,and two unclassified orders.LW-AFC had influences on bacterial taxa correlated with the abilities of learning and memory in SAMP8 mice and restored them to SAMR1 mice.CONCLUSION The effects of LW-AFC on improving cognitive impairments of SAMP8 mice might be via modulating intestinal microbiome and LW-AFC could be used as a potential anti-AD agent.

LW-AFC,a new formula derived from Liuwei Dihuang decoction,ameliorates behavioral and pathological deterioration via modulating the neuroendocrineimmune system in Alzheimer disease mouse models

OBJECTIVE Alzheimer disease(AD),the most common cause of dementia among older people,could not be prevented,halted,or reversed up till now.A large body of pharmacological study has revealed that Liuwei Dihuang(LW) possesses potential therapeutic effects on AD.LW-AFC is key fractions fromLW.In the present study,we investigated the effect of LW-AFC on AD mouse models.METHODS PrP-hAβPPswe/PS1ΔE9(APP/PS1) mice and senescence-accelerated mouse prone 8 strain(SAMP8),classic AD animal models,were employed.After the treatment of LW-AFC,mice were cognitively evaluated in behavioral experiments.Neuron loss,amyloid-β(Αβ)deposition,and Αβ level were analyzed using Nissl staining,immunofluorescence,and an AlphaLISA assay,respectively.Multiplex bead analysis,a radioimmunoassay,immunochemiluminometry,and an ELISA were used to measure cytokine and hormone levels.Lymphocyte subsets were detected using fl ow cytometry.RESULTS LW-AFC ameliorated the cognitive impairment observed in APP/PS1 and SAMP8 mice,including the impairment of object recognition memory,spatial learning and memory,and active and passive avoidance.In addition,LW-AFC alleviated the neuron loss in the hippocampus,suppressed amyloid-β(Αβ) deposition in the brain,and reduced the concentration of Aβ1-42 in the hippo.campus and plasma of APP/PS1 mice.LW-AFC treatment also significantly restored the imbalance of hypothalamic-pituitary-adrenal(HPA) and hypothalamic-pituitary-gonadal(HPG) axis,enhanced the proliferation of splenocytes,corrected the disorder of lymphocyte subsets,and regulated the abnormal production of cytokine in APP/PS1 and SAMP8 mice.Effects of LW-AFC on pharmacodynamics and neuroendocrine immunomodulation network in APP/PS1 and SAMP8 mice were better than meman.tine and donepezil.CONCLUSION LW-AFC ameliorated the behavioral and pathological deterioration of AD mouse models via the restoration of the NIM network,which supports the use of LW-AFC as a potential agent for AD therapy.

Liuwei Dihuang Decoction improves cognitive impairments via regulating immune system in APP/PS1 transgenic mouse, a mouse model of Alzheimer disease

OBJECTIVE To investigate the effect and mechanisms of Liuwei Dihuang Decoction(LW) on cognition in PrP-hAβPPswe/PS1ΔE9(APP/PS1) transgenic mice.METHODS LW was adminis.trated with oral for 3 months.The locomotor activity test was performed to investigate the spontaneous motor activity of mice.The Morris water maze test and shuttle box test were performed to investigate the spatial learning and memory and active avoidance response respectively.The Αβ deposits and neuron loss in the hippocampus was detected by immunofluorescence staining and nissl staining respectively.The flow cytometry was employed to investigate the lymphocyte subsets of the mice.The 3 H-thymidine incorporation was performed to investigate the splenocytes proliferation.RESULTS The treatment of LW ameliorated the impairments of spatial learning and memory and active and passive avoidance in APP/PS1 mice.The administration of LW alleviated neuron loss in the brain,suppressed amyloid-β(Αβ) deposits in the hippocampus of APP/PS1 mice.The treatment of LW significantly increased ConAand LPS-induced proliferation of splenocytes,increased CD3+ T cells and CD19+ B cells in the spleen lymphocytes and reduced Gr1+ cells in APP/PS1 mice.CONCLUSION This data indicated the adminis.tration of LW ameliorated behavioral and pathological deterioration via regulating immune function.

应用OCTA观察青少年近视患者配戴角膜塑形镜后眼底微循环的变化

目的:应用光学相干断层扫描血管成像(OCTA)观察青少年近视患者配戴角膜塑形镜后眼底微循环的变化。方法:前瞻性研究。收集2021-04/2022-06于我院就诊并选择角膜塑形镜矫正视力的中低度青少年近视患者40例40眼,分别于戴镜前、戴镜后1、3、6mo评估裸眼远视力、眼轴,并采用OCTA观察视网膜浅层血流密度(SVD)和深层血流密度(DVD)、视网膜厚度(CRT)、中心凹无血管区面积(FAZ-A)和周长(FAZ-P)、视神经纤维层(RNFL)厚度、盘周放射状毛细血管血流密度(RPCD)变化情况。结果:戴镜后1、3、6mo,纳入患者裸眼远视力较戴镜前显著改善(P<0.001),眼轴长度无显著变化(P>0.05)。戴镜前后,纳入患者中心凹象限SVD、中心凹和下方象限DVD均有差异(P<0.01),但CRT、FAZ-A和FAZ-P、RNFL厚度、RPCD均无差异(P>0.05)。结论:低中度青少年近视患者配戴角膜塑形镜可显著改善视力,黄斑区局部视网膜血流密度增加。

氧化石墨烯的尺寸对碳纤维/环氧树脂湿热界面性能的影响

通过Hummers法获得两种尺寸的氧化石墨烯(GO),利用模压成型制备GO改性碳纤维增强环氧树脂复合材料(GO/CF/EP),并对复合材料进行湿热处理,利用层间剪切性能、动态热机械性能和微观形貌分析室温干态和湿热处理后复合材料的改性效果。结果表明:GO对复合材料的层间剪切强度和玻璃化转变温度均具有良好的改善作用;室温干态时两种尺寸GO对复合材料层间剪切强度的改善效果基本相同;随GO含量增加,小尺寸GO使复合材料的湿热层间剪切强度下降更快,GO含量为0.1%(质量分数,下同)时对复合材料的层间剪切性能改善作用较好,而GO含量为0.2%时对复合材料的玻璃化转变温度改善更好。随GO含量增加,GO-EP复合树脂基体的放热峰向低温移动,小尺寸GO使复合树脂的凝胶时间变短。微观形貌分析表明,GO的存在有利于增加复合材料破坏时的裂纹扩散路径,从而更有助于材料耗散裂纹尖端能量。

高离子电导率聚离子液体基自修复固态电解质的制备

采用可逆加成-断裂链转移(RAFT)聚合法成功合成了高分子量、窄分布的聚[1-(4-乙烯基苄基)-3-甲基咪唑双三氟甲烷磺酰亚胺](P[VBMIM][TFSI]),并将其与双三氟甲烷磺酰亚胺锂(LiTFSI)共混,通过溶液浇筑法制备了固态聚合物电解质(SPEs)。首先通过力学性能、流变学、热分析和电化学测试研究了P[VBMIM][TFSI]本体结构与性能的关系。随相对分子质量增加,P[VBMIM][TFSI]缠结程度逐渐加深,拉伸强度大幅度提升,而离子电导率与热降解温度变化不大。进一步对固态聚合物电解质进行更深入的电化学测试和分析。结果表明,SPEs在30℃时离子电导率最高可达到4.06×10^(-4) S/cm,锂离子迁移数为0.34,电化学窗口达到了4.5V。通过光学显微镜观察其自修复性,SPEs在室温时20min便可平复表面划痕,且具备良好的弹性,可以在5min内几乎完全回复拉伸长度。

丝状真菌Podospora anserina AA11家族裂解多糖单加氧酶基因的鉴定和功能研究

辅助活性蛋白家族(auxiliary activity family,AA family)中的裂解多糖单加氧酶(lytic polysaccharide monooxygenase,LPMO)能催化纤维素、几丁质和淀粉等多种难降解碳水化合物的氧化解聚。尽管目前对LPMO的酶学研究较多,但对LPMO基因失活的研究却鲜有报道。本研究利用同源重组方法定点敲除丝状真菌Podospora anserina中AA11家族的5个LPMO基因PaLPMO11A(Pa_4_4790)、PaLPMO11B(Pa_1_5310)、PaLPMO11C(Pa_2_7840)、PaLPMO11D(Pa_2_8610)和PaLPMO11E(Pa_3_9420),分别构建了单突变体ΔPaLPMO11A(ΔA)、ΔPaLPMO11B(ΔB)、ΔPaLPMO11C(ΔC)、ΔPaLPMO11D(ΔD)和ΔPaLPMO11E(ΔE),然后通过遗传杂交构建所有多基因突变体。通过在不同碳源培养基上的表型分析、DAB和NBT染色以及纤维素酶活测定分析野生型菌株与突变型菌株在生长速率、有性生殖、氧化应激和纤维素降解能力等方面的差异,揭示LPMO11基因在P.anserina菌株的生长发育和木质纤维素降解过程中的作用。实验结果表明,在不同纤维素碳源上,ΔBΔCΔE、ΔAΔBΔCΔE、ΔAΔCΔDΔE和ΔAΔBΔCΔDΔE突变型菌株的有性生殖能力降低,其余突变型菌株的孢子萌发效率、生长速率和生殖能力几乎没有差异。PaLPMO11家族5个基因的同时缺失,会导致菌株利用各种碳源的能力明显降低、生长速率降低、孢子萌发率降低、子实体数减少、部分子实体发育异常、寿命缩短和降解纤维素的能力显著下降,但仍有野生型45%以上的总纤维素酶活力。上述结果表明,LPMO11基因可能参与P.anserina的生长发育、有性生殖、衰老和纤维素降解过程。本研究为系统阐述丝状真菌P.anserina中木质纤维素降解的调控机制提供参考。

Refined Aerodynamic Test of Wide-Bodied Aircraft and Its Application

The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.