电荷迁移方向调控的BiVO_(4)量子点/苝四羧酸Z型异质结与纳米金修饰在人工光合成H_(2)O_(2)中的协同作用

利用太阳能驱动的半导体光催化技术将H_(2)O和O_(2)转化为H_(2)O_(2),是传统蒽醌工艺的可持续替代方案之一.在光催化O_(2)还原生产H_(2)O_(2)的过程中,主要涉及到O_(2)的还原和H_(2)O的氧化两个半反应.然而,单一的窄带隙半导体往往难以满足整体反应的热力学电位要求.为了克服这一挑战,研究人员借鉴自然光合作用的原理,提出了构建Z型异质结体系的策略.这种体系不仅能有效促进电荷的分离,从而增强光催化效率,而且能保留光生电荷较强的氧化还原能力,这对于H_(2)O_(2)的光合成至关重要.此外,O_(2)的活化对于H_(2)O_(2)光合成同样重要.然而,目前在构建Z型异质结时,对于Z型异质结的两组分自身电荷传输方向的匹配性鲜有关注.因此,构建具有电荷定向传输的Z型异质结,并精准负载O_(2)活化位点,对于提高H_(2)O_(2)的光合成效率和稳定性具有重要意义.本文以苝-3,4,9,10-四羧酸二酐(PTCDA)为前驱体,在水解的过程中,引入预制备的钒酸铋量子点(BQD),原位构建BQD/PTA Z型异质结.然后,通过低温辅助光还原策略将纳米Au精确修饰在苝四甲酸(PTA)上,制得具有定向电荷传输的BQD/PTA-Au Z型异质结.形貌表征结果表明,PTA的形态为平均厚度为3.5 nm的不规则纳米片,其表面均匀负载了直径约为7 nm的BQD纳米颗粒,而超小的Au纳米粒子(直径约为5 nm)则负载在PTA纳米片的边缘.优化后的BQD/PTA-Au异质结光催化H_(2)O_(2)产率为218.6μmol g^(-1)h^(-1),约为PTA纳米片的6.4倍;此外,在405 nm波长下,该异质结的表观量子产率为PTA的4.8倍.在模拟太阳光条件下,BQD/PTA-Au异质结的太阳能到化学能转换效率(SCC)为0.47%;且在连续5次的循环实验中表现出良好的稳定性.光物理和光化学测试结果表明,BQD/PTA Z型异质结的构建显著促进了PTA的电荷分离,Au修饰后复合体的电荷分离进一步增强.扫描开尔文探针(SKP)测试结果表明,BQD和PTA的能带结构满足Z型电荷传输路径,电子顺磁共振和原位X射线光电子能谱分析结果表明,所构建的Z型异质结由于电荷传输方向匹配,显著促进·O_(2)-自由基的形成;而后续的Au修饰则能够定向接受来自PTA的光生电子.旋转圆盘电极测试结果表明,BQD/PTA-Au的平均电子转移数最接近2,说明其遵循两电子氧还原反应(ORR)路径.结合物种捕获实验推测,·O_(2)-自由基是BQD/PTA-Au异质结光合成H_(2)O_(2)的主要活性物种.原位漫反射红外光谱测试证实,纳米Au修饰可进一步提高O_(2)在催化剂表面吸附,并加速两电子的O_(2)还原反应.综上,本文围绕着具有各向异性电荷迁移的PTA,设计构建了电荷定向迁移的Z型异质结体系,实现了高效的H_(2)O_(2)光合成,为高效Z型异质结体系设计构建提供了新思路.

Identif ication of a hypersensitive response core peptide of HrpZ and its role in increasing grape downy mildew resistance

Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts of soluble fusion proteins of harpin HrpZ and its subpeptides were obtained via the optimized induction conditions(28℃ with 0.5 mmol·L^(-1) IPTG for 6 h)in Escherichia coli BL21(DE3).Hypersensitive response(HR)assays demonstrated that the C-terminal 66 aa of HrpZ(HrpZ_C_2_2)elicited a strong HR in tobacco(Nicotiana benthamiana)and grape(Flame Seedless)leaves.Additionally,treatment with HrpZ,and particularly HrpZ_C_2_2,significantly reduced the disease incidence and severity index of field vine leaves and those inoculated with downy mildew.The determination of the physiological parameters indicated that HrpZ,and especially HrpZ_C_2_2,improved the photosynthesis-and chlorophyll fluorescence-related parameters,enhanced the activity of defense-related enzymes,including SOD,POD,CAT and PAL,and increased the H_(2)O_(2) level.Collectively,we efficiently expressed a core peptide of HrpZ and elucidated its strong ability to elicit a HR and resistance to downy mildew.This research provides insight into understanding the structure and function of HrpZ and will advance the application of HrpZ_C_2_2 to increase the resistance of grapevine to downy mildew.

On Klein tunneling of low-frequency elastic waves in hexagonal topological plates

Incident particles in the Klein tunnel phenomenon in quantum mechanics can pass a very high potential barrier.Introducing the concept of tunneling into the analysis of phononic crystals can broaden the application prospects.In this study,the structure of the unit cell is designed,and the low frequency(<1 k Hz)valley locked waveguide is realized through the creation of a phononic crystal plate with a topological phase transition interface.The defect immunity of the topological waveguide is verified,that is,the wave can propagate along the original path in the cases of impurities and disorder.Then,the tunneling phenomenon is introduced into the topological valley-locked waveguide to analyze the wave propagation,and its potential applications(such as signal separators and logic gates)are further explored by designing phononic crystal plates.This research has broad application prospects in information processing and vibration control,and potential applications in other directions are also worth exploring.

Melatonin enhances salt tolerance by promoting MYB108A-mediated ethylene biosynthesis in grapevines

The signal molecules melatonin and ethylene play key roles in abiotic stress tolerance.The interplay between melatonin and ethylene in regulating salt tolerance and the underlying molecular mechanism of this interplay remain unclear.Here,we found that both melatonin and 1-aminocyclopropane-1-carboxylic acid(ACC,a precursor of ethylene)enhanced the tolerance of grapevine to NaCl;additionally,ethylene participated in melatonin-induced salt tolerance.Further experiments indicated that exogenous treatment and endogenous induction of melatonin increased the ACC content and ethylene production in grapevine and tobacco plants,respectively.The expression of MYB108A and ACS1,which function as a transcription factor and a key gene involved in ethylene production,respectively,was strongly induced by melatonin treatment.Additionally,MYB108A directly bound to the promoter of ACS1 and activated its transcription.MYB108A expression promoted ACC synthesis and ethylene production by activating ACS1 expression in response to melatonin treatment.The suppression of MYB108A expression partially limited the effect of melatonin on the induction of ethylene production and reduced melatonin-induced salt tolerance.Collectively,melatonin promotes ethylene biosynthesis and salt tolerance through the regulation of ACS1 by MYB108A.

Melatonin alters the secondary metabolite profile of grape berry skin by promoting VvMYB14-mediated ethylene biosynthesis

The interplay between melatonin and ethylene in the regulation of fruit metabolism and the underlying molecular mechanism of this interplay remain largely unclear.Here,widely targeted metabolomics analysis revealed a total of 464 metabolites present in berry skin.Among them,27 significantly differentially accumulated metabolites(DAMs)were produced in response to melatonin treatment in the presence or absence of 1-MCP.Most of the DAMs were secondary metabolites,including flavonoids,phenolic acids,stilbenes,and flavonols.Additionally,the accumulation of 25 DAMs was regulated by melatonin via ethylene.RNA-seq analysis indicated that melatonin primarily regulated the pathways of plant hormone signal transduction and secondary metabolite biosynthesis via ethylene.Gene-metabolite association analysis showed that melatonin regulated the expression of the VvSTS1,VvF3H,VvLAR2,and VvDFR genes,suggesting that these genes may play key roles in regulating secondary metabolites in the skin;additionally,VvMYB14 and VvACS1 were suggested to be involved in the regulation of secondary metabolites.Further experiments revealed that melatonin induced the expression of VvMYB14 and that VvMYB14 increased ethylene production by transcriptionally activating VvACS1,thereby affecting the accumulation of secondary metabolites.Collectively,melatonin promotes ethylene biosynthesis and alters secondary metabolite accumulation through the regulation of VvACS1 by VvMYB14.

Melatonin promotes ripening of grape berry via increasing the levels of ABA, H2O2, and particularly ethylene

The role of melatonin in the regulation of fruit ripening and the mechanism involved remain largely unknown.In“Moldova”grape berries,melatonin accumulated rapidly from onset of veraison,reached the maximum at 94 days after bloom(DAB)and then exhibited low levels at late stages of berry ripening.By contrast,abscisic acid(ABA)and hydrogen peroxide(H2O2)exhibited different accumulation patterns,and ethylene was primarily produced immediately before veraison.Further experiments demonstrated that 10 and particularly 100µM melatonin treatments increased the levels of ABA,H2O2,and ethylene production and promoted berry ripening compared with the control treatment,whereas 0.1 and 1.0µM melatonin did not lead to clear effects.Additionally,the application of inhibitors indicated that ABA,H2O2,and ethylene participated in the regulation of berry ripening induced by melatonin,and the suppression of ethylene biosynthesis produced the greatest inhibitory effects on melatonin-induced berry ripening compared with those of ABA and H2O2.Melatonin also promoted ethylene production via ABA.In summary,10 and particularly 100µM melatonin treatments promoted berry ripening,which was accomplished,at least partially,via the other signaling molecules of ABA,H2O2,and particularly ethylene.This research provides insight into melatonin signaling during berry ripening and may advance the application of melatonin to accelerate berry ripening.

清凉慢岛——重庆九龙半岛城市更新规划设计研究

在我国城市经历了快速城市化进程后,城市更新成为转型发展的重要途径。低碳生态和高质量发展是目前城市更新中的关键议题。“山城火炉”重庆在过去40年的快速扩张发展后,亟需探索可持续的城市更新路径。尚未更新的九龙半岛成为研究和规划设计的典型地区。本文从生态、历史、产业、社会、交通等方面分析了九龙半岛的资源禀赋,判断其具有成为中心城区凉岛绿心、建构地区级历史资源体系和成为世界级双年展场的潜力,据此提出将“清凉慢岛”作为其发展定位。规划设计围绕“清凉”和“慢”两大主题,通过“清凉生态”“低碳交通”“慢体验”“慢创作”和“慢生活”五大策略,谋划由总体规划到地段设计的更新路径,并探索实施保障。本文试图建构一种比较视野下的面向生态和经济的定性、定量分析方法,并落实到设计方案中,提出对存量地区更新的多维度解决方案。

VvMYB14 participates in melatonin-induced proanthocyanidin biosynthesis by upregulating expression of VvMYBPA1 and VvMYBPA2 in grape seeds

This work demonstrated that melatonin increases continuously in seeds,particularly seed coats,during berry ripening.Exogenous melatonin treatments significantly increased the proanthocyanidin(PA)content,partially through ethylene signaling,in seed coats.VvMYB14 expression exhibited patterns similar to melatonin accumulation over time,which was largely induced by melatonin treatment in seed coats during berry ripening.Additionally,VvMYB14 bound to the MBS element of the VvMYBPA1 promoter to activate expression.VvMYB14 overexpression largely upregulated expression of VvMYBPA1,VvMYBPA2 and VvLAR1 and increased the PA content in grape seed-derived calli.Similar increases in AtTT2 and AtBAN expression and PA content were found in VvMYB14-overexpressing Arabidopsis seeds.It was also observed that VvMYB14 overexpression increased ethylene production and thereby induced expression of VvERF104,which bound to the ERF element of the VvMYBPA2 promoter and activated its expression.Additionally,VvERF104 suppression reduced the VvMYB14 overexpression-induced increases in expression of VvMYBPA2 and VvLAR1 and PA content.Further experiments revealed that melatonin-induced increases in the expression of VvMYBPA1,VvMYBPA2,VvERF104 and VvLAR1 and PA accumulation were significantly reduced in VvMYB14-suppressing grape calli and leaves.Collectively,VvMYB14 mediates melatonin-induced PA biosynthesis by directly transactivating VvMYBPA1 expression and indirectly upregulating VvMYBPA2 expression via VvERF104.

Technoeconomically competitive four-terminal perovskite/graphenesilicon tandem solar cells with over 20% efficiency

Perovskite/Silicon(PS) tandem solar cells have attracted much interest over recent years. However, the most popular crystalline silicon solar cells utilized in tandems require complicated fabrication processes mainly including texturization, diffusion, passivation and metallization, which takes up much cost in photovoltaic market. Here, we report a facile graphene/silicon(Gr/Si) solar cell featuring of lowtemperature( 200 °C) processing and an efficiency of 13.56%. For reducing the heat dissipation loss of high energy photon, the perovskite solar cell(PSC) with a wide band gap of 1.76 e V was adopted as the top cell for the tandem. To reduce the loss of parasitic absorption in hole transport layers(HTLs),thickness of Spiro-OMe TAD is re-optimized by compromising the efficiency and the optical transmittance of the devices. As a result, the semitransparent top perovskite solar cell yields a highest efficiency of13.35%. Furthermore, we firstly achieved a low-temperature-processed four-terminal(4-T) perovskite/graphene-silicon(PGS) heterojunction tandem solar cell with the efficiency of 20.37%. The levelized cost of electricity(LCOE) of PGS 4-T modules were estimated to a competitive price, exhibiting much greater potential for practical application compared to that of PS 4-T modules.

共价有机框架材料在碘捕捉方面的研究进展

随着核工业的发展,放射性碘被确定为最危险的核废料之一。放射性碘捕获对于降低核废水污染也有着重要意义。共价有机框架材料(COFs)是一种通过共价键连接形成的晶态多孔有机材料,因其具有大的比表面积、规则的孔道结构和高化学稳定性等特点,因其本身的结构特征和COFs吸附位点易被碘分子占据,COFs被认为是理想的碘捕捉材料。本文主要综述了具有周期性多孔结构的COFs材料在碘捕捉领域的研究进展。首先,简要论述近年来各课题组对于亚胺键连接的COFs在碘捕获方面的进展。其次,探讨复合型COFs和离子型COFs的碘捕获能力。最后,探讨高效碘捕获COFs材料拓展至规模化应用的潜力并展望该领域未来的发展形势。

气温和根区温度对葡萄叶片光合荧光特性的影响

为探究气温和根区温度对葡萄(Vitis vinifera)叶片光合荧光特性的影响,以一年生巨峰葡萄为试材,设置对照、高气温、高根区温度和两者交叉作用共4组处理。结果表明,相较于对照和高气温,高根区温度以及交叉处理叶片最大光化学效率(F_(v)/F_(m))降低更明显;与对照相比,高根区温度以及高气温与高根区温度交叉处理下光系统II(PSII)实际光化学效率Y(II)显著降低,非调节能量耗散的量子产量Y(NPQ)及QA氧化还原状态(1–qP)值显著上升。同时,高根区温度以及高气温与高根区温度交叉处理显著增加了J点的可变荧光(V_(j)),而用于电子传递的量子产额(φ_(Eo))及性能指数(PI_(ABS))显著降低。此外,高根区温度以及高气温与高根区温度交叉处理下单位面积有活性的反应中心数目(RC/CS_(m))也显著下降,K点相对可变荧光(W_(k))明显上升。综上所述,高根区温度是高气温与根区高温交叉胁迫的主导因子,PSII受体侧是主要的伤害位点,高气温加剧了高根区温度对PSII造成的伤害。

30-Year Trends in the Disease Burden, Incidence, and Prevention of Pneumoconiosis

The global incidence of pneumoconiosis,a lung disease caused by inhaling industrial dust,has increased by 61.5%from 1990 to 2019,according to a recent report.China had the highest number of cases in 2019,followed by India and the United States.The all-age standard incidence rate for pneumoconiosis was 2.39 per 100,000 population in 2019,with China also having the highest rate.However,there was a decrease in the incidence rate in Belgium and Italy during the same period.The report also highlights regional variations in the changing trend,with the largest increase in cases observed in North Africa and the Middle East.Improved dust prevention and control measures are urgently needed to reduce workplace dust exposure and combat the rising cases of pneumoconiosis globally.

Identification of diverse novel genomoviruses in gut of wild birds

Genomoviridae is a virus family belonging to circular replication associated protein encoding ssDNA(CRESS-DNA)viruses,which have diverse genomic architecture and are widely distributed among different ecosystems.In this study,we characterized 39 novel genomovirus genomes including 3 from wild egrets,9 from wild cranes,as well as 27 from wild finches in three different types of cloacal swabs of wild bird sampled in the station of Xinqing bird ringing,Maoershan Nature Reserve in Heilongjiang Province,Changbai Mountain in Jilin Province,and Hangzhou Wetland Park in Zhejiang Province,China.Here,using a Rep sequence phylogeny-based analysis,we divided the 39 genomoviruses into 8 genera within the family Genomoviridae,including Gemycircularvirus(n=20),Gemykibivirus(n=3),Gemygorvirus(n=2),Gemyvongvirus(n=2),Gemykolovirus(n=3),Gemykrogvirus(n=6),Gemytondvirus(n=1),Gemyduguivirus(n=1)and one unclassified genomovirus.The 39 genomovirus genomes belong to 36 species(27 of which are new)based on the currently accepted genomovirus pairwise nucleotide sequence identity species demarcation threshold of 78%.Overall,the research enriches our knowledge of CRESS-DNA viral diversity in China and emphasizes the prevalence of genomoviruses in nature.

Single-cell analysis reveals the potential mechanisms of pyrotinib resistance in non-small cell lung cancer

Dear Editor,Lung cancer still remains the leading cause of cancer death worldwide,80-90%of which are non-small cell lung cancer(NSCLC).In 2-3%of NSCLC patients,mutations in human epidermal growth factor receptor 2(HER2)have been identified as oncogenic drivers.However,HER2 has been poorly reported as a therapeutic target for advanced NSCLC despite of the outstanding improvements in breast cancer receiving HER2-targeting regimens.

Exogenous L-tryptophan treatment increases the concentrations of melatonin and aroma compounds in grape berries and wine

L-Tryptophan(Trp)is a substrate for the biosynthesis of melatonin,and melatonin is a signal molecule that alters the secondary metabolite profile;whether Trp treatments promote the biosynthesis of melatonin to regulate aroma compounds in grape berries and wine remains unclear.Here,the content of melatonin was higher in Marselan grapes and wine than that in other grape cultivars.Marselan grapes were subjected to 30 different Trp treatments.The content of melatonin and aroma compounds in Marselan grapes was increased by several treatments.Increases in the content of volatiles were mainly driven by increases in aldehydes.Hexanal,the most abundant aldehyde compound,was the main contributor to increases in aldehydes following Trp treatment.The results of our study indicate that the root application of 250 mg/L L-tryptophan during the fruiting expansion stage and the spraying application of 50 mg/L L-tryptophan spray during the veraison stage were the optimal treatments because the content of melatonin and aroma compounds,as well as other basic quality parameters,were highest in Trp-treated grape berries and wine in these treatments.Overall,these two effective Trp treatments could be used to enhance the content of melatonin and aroma compounds in Marselan grapes,and this could increase the economic value of this cultivar.