Construction of a Cu@hollow TS-1 nanoreactor based on a hierarchical full-spectrum solar light utilization strategy for photothermal synergistic artificial photosynthesis

The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosynthesis by coupling both photochemistry and thermochemistry.However,strategies for maximizing the use of solar spectra with different frequencies in photothermal catalysis are urgently needed.Here,a hierarchical full-spectrum solar light utilization strategy is proposed.Based on this strategy,a Cu@hollow titanium silicalite-1 zeolite(TS-1)nanoreactor with spatially separated photo/thermal catalytic sites is designed to realize high-efficiency photothermal catalytic artificial photosynthesis.The space-time yield of alcohol products over the optimal catalyst reached 64.4μmol g−1 h−1,with the selectivity of CH3CH2OH of 69.5%.This rationally designed hierarchical utilization strategy for solar light can be summarized as follows:(1)high-energy ultraviolet light is utilized to drive the initial and difficult CO_(2) activation step on the TS-1 shell;(2)visible light can induce the localized surface plasmon resonance effect on plasmonic Cu to generate hot electrons for H2O dissociation and subsequent reaction steps;and(3)low-energy near-infrared light is converted into heat by the simulated greenhouse effect by cavities to accelerate the carrier dynamics.This work provides some scientific and experimental bases for research on novel,highly efficient photothermal catalysts for artificial photosynthesis.

Proximity Effect of Fe-Zn Bimetallic Catalysts on CO_(2) Hydrogenation Performance

The interaction between a promoter and an active metal crucially impacts catalytic performance.Nowadays,the influence of promoter contents and species has been intensively considered.In this study,we investigate the effect of the iron(Fe)-zinc(Zn)proximity of Fe-Zn bimetallic catalysts on CO_(2)hydrogenation performance.To eliminate the size effect,Fe_(2)O_(3)and ZnO nanoparticles with uniform size are first prepared by the thermal decomposition method.By changing the loading sequence or mixing method,a series of Fe-Zn bimetallic catalysts with different Fe-Zn distances are obtained.Combined with a series of characterization techniques and catalytic performances,Fe-Zn bimetallic proximity for compositions of Fe species is discussed.Furthermore,we observe that a smaller Fe-Zn distance inhibits the reduction and carburization of the Fe species and facilitates the oxidation of carbides.Appropriate proximity of Fe and Zn(i.e.,Fe_1Zn_(1)-imp and Fe_(1)Zn_(1)-mix samples)results in a suitable ratio of the Fe_5C_(2)and Fe_(3)O_(4)phases,simultaneously promoting the reverse water-gas shift and Fischer-Tropsch synthesis reactions.This study provides insight into the proximity effect of bimetallic catalysts on CO_(2)hydrogenation performance.

基于管道声模态的SCR催化消声器传递损失分析

柴油机SCR选择性催化还原技术是欧五排放标准的重要技术路线之一,SCR催化消声器实现柴油机尾气净化和排气减噪的双重功能。文章应用三维声学软件Virtual.Lab,基于管道声模态法结合传递导纳函数,通过对常温及高温下的SCR消音器的传递损失进行计算得到其具有较好的消声性能,为优化和改进排气系统的声学性能提供仿真技术支持。

某增压发动机的进气系统声学性能研究

发动机进气系统噪声是汽车的主要噪声源之一,进气系统不仅需要为发动机提供很好的空气动力学性能,还需要有良好的消声能力。文章以某增压发动机车型的进气系统为研究对象,以传递损失为指标,运用声学软件Virtual.lab分析其0到4000Hz频率段的声学特性,并在此基础上添加若干个消声元件来提高进气系统全频率段的消声能力。

A Distributed Strategy for Defensing Objective Function Attack in Large-scale Cognitive Networks

Most of existed strategies for defending OFA (Objective Function Attack)are centralized, only suitable for small-scale networks and stressed on the computation complexity and traffic load are usually neglected. In this paper, we pay more attentions on the OFA problem in large-scale cognitive networks, where the big data generated from the network must be considered and the traditional methods could be of helplessness. In this paper, we first analyze the interactive processes between attacker and defender in detail, and then a defense strategy for OFA based on differential game is proposed, abbreviated as DSDG. Secondly, the game saddle point and optimal defense strategy have proved to be existed simultaneously. Simulation results show that the proposed DSDG has a less influence on network performance and a lower rate of packet loss.More importantly, it can cope with the large range

The light and hypoxia induced gene ZmPORB1 determines tocopherol content in the maize kernel

Tocopherol is an important lipid-soluble antioxidant beneficial for both human health and plant growth. Here, we fine mapped a major QTLqVE1 affecting γ-tocopherol content in maize kernel, positionally cloned and confirmed the underlying gene ZmPORB1(por1), as a protochlorophyllide oxidoreductase. A 13.7 kb insertion reduced the tocopherol and chlorophyll content, and the photosynthetic activity by repressing ZmPORB1 expression in embryos of NIL-K22, but did not affect the levels of the tocopherol precursors HGA(homogentisic acid)and PMP(phytyl monophosphate). Furthermore, ZmPORB1 is inducible by low oxygen and light, thereby involved in the hypoxia response in developing embryos. Concurrent with natural hypoxia in embryos, the redox state has been changed with NO increasing and H_(2)O_(2) decreasing, which lowered γ-tocopherol content via scavenging reactive nitrogen species. In conclusion, we proposed that the lower lightharvesting chlorophyll content weakened embryo photosynthesis, leading to fewer oxygen supplies and consequently diverse hypoxic responses including an elevated γ-tocopherol consumption. Our findings shed light on the mechanism for fine-tuning endogenous oxygen concentration in the maize embryo through a novel feedback pathway involving the light and low oxygen regulation of ZmPORB1 expression and chlorophyll content.

Making small molecules in plants:A chassis for synthetic biology-based production of plant natural products

Plant natural products have been extensively exploited in food,medicine,flavor,cosmetic,renewable fuel,and other industrial sectors.Synthetic biology has recently emerged as a promising means for the cost-effective and sustainable production of natural products.Compared with engineering microbes for the production of plant natural products,the potential of plants as chassis for producing these compounds is underestimated,largely due to challenges encountered in engineering plants.Knowledge in plant engineering is instrumental for enabling the effective and efficient production of valuable phytochemicals in plants,and also paves the way for a more sustainable future agriculture.In this manuscript,we briefly recap the biosynthesis of plant natural products,focusing primarily on industrially important terpenoids,alkaloids,and phenylpropanoids.We further summarize the plant hosts and strategies that have been used to engineer the production of natural products.The challenges and opportunities of using plant synthetic biology to achieve rapid and scalable production of high-value plant natural products are also discussed.

Salicylic acid biosynthesis is not from phenylalanine in Arabidopsis

The phytohormone salicylic acid(SA)regulates biotic and abiotic stress responses in plants.Two distinct biosynthetic pathways for SA have been well documented in plants:the isochorismate(IC)pathway in the chloroplast and the phenylalanine ammonia-lyase(PAL)pathway in the cytosol.However,there has been no solid evidence that the PAL pathway contributes to SA biosynthesis.Here,we report that feeding Arabidopsis thaliana with Ring-13C-labeled phenylalanine(13C6-Phe)resulted in incorporation of the13C label not into SA,but into its isomer 4-hydroxybenzoic acid(4-HBA)instead.We obtained similar results when feeding13C6-Phe to the SA-deficient ics1 ics2 mutant and the SA-hyperaccumulating mutant s3h s5h.Notably,we detected13C6-SA when13C6-benzoic acid(BA)was provided,suggesting that SA can be synthesized from BA.Furthermore,despite the substantial accumulation of SA upon pathogen infection,we did not observe incorporation of13C label from Phe into SA.We also did not detect13C6-SA in PAL-overexpressing lines in the kfb01 kfb02 kfb39 kfb50 background after being fed13C6-Phe,although endogenous PAL levels were dramatically increased.Based on these combined results,we propose that SA biosynthesis is not from Phe in Arabidopsis.These results have important implications for our understanding of the SA biosynthetic pathway in land plants.

宫颈胃型腺癌30例临床分析

目的探讨宫颈胃型腺癌(gastric-type endocervical adenocarcinoma,G-EAC)的临床特征、诊疗及预后。方法回顾性分析2017年1月—2022年6月郑州大学第一附属医院收治的30例G-EAC患者的临床资料,并对患者进行随访,评估预后。结果30例G-EAC中,I期10例,Ⅱ期2例,III期15例,Ⅳ期3例。HPV阳性率为18.2%,TCT阳性率为52.2%。仅11例术前确诊为G-EAC,8例因宫颈活检病理确诊,3例因宫颈锥形切除术后病理确诊;15例术前诊断为宫颈腺癌,1例误诊为子宫内膜癌,1例误诊为原发性卵巢癌,2例因良性病变行子宫及双侧附件切除术,均于术后病理确诊为G-EAC。61.5%患者病变累及宫体,52.0%伴有淋巴结转移,38.5%见脉管内癌栓,26.9%伴有卵巢转移,23.1%阴道受累,15.4%出现神经侵犯,7.7%病变侵犯直肠。随访至2022年9月,6例死于本病,4例复发,8例未控,5例失访;5年生存率56.7%,5年无进展生存率44.7%。结论G-EAC早期诊断困难,误诊率高,易发生浸润和转移,预后差,需重视阴道长期排液的症状及宫颈部位影像学特征,结合组织病理学形态和免疫组织化学染色可明确诊断,做到早诊早治,降低误诊率,以期改善预后。

Size dependence of carbon-encapsulated iron-based nanocatalysts for Fischer–Trposch synthesis

The conversion from syngas derived from non-petroleum recourses to liquid fuels and chemicals via Fischer–Tropsch synthesis(FTS)is regarded as an alternative and potential route.Developing catalyst with controllable particle size and clarifying size effect are of significance to promote the process.Herein,we engineered carbon-encapsulation structure to restrict particle growth but avoid strong metal–support interactions.The prepared carbon-encapsulated nanoparticles(Fe@C)showed a superior catalytic activity compared with conventional carbon-supported nanoparticles(Fe/C).By tuning particle size from 3.0 to 9.1 nm,a volcano-like trend of iron time yield(FTY)peaked at 2659μmol·gFe^(−1)·s^(−1)is obtained with an optimum particle size of 5.3 nm.According to temperature-programmed reduction and desorption results,a linear relationship between apparent turnover frequency and CO dissociation capacity was established.The enhanced CO dissociative adsorption along with weakened H_(2)activation on larger nanoparticles resulted in higher C_(5+)selectivity.This study provides a strategy to synthesize carbon supported metal catalysts with controllable particle size and insight into size effect on Fe-based catalytic FTS.

西安市莲湖区2008-2017年丙肝流行特征分析及趋势预测

目的了解2008-2017年西安市莲湖区丙肝流行特征并进行趋势预测,为莲湖区的防治工作提供科学依据。方法采用描述性流行病学方法对资料进行统计分析,利用2008-2017年丙肝年发病率建立灰色模型GM(1,1),并预测2018年、2019年丙肝发病情况。结果2008-2017年莲湖区累计报告丙肝病例2376例,年均发病率为33.11/10万,发病总体呈逐年上升趋势,历年各月均有发病,无明显季节特征;报告病例数以30~79岁年龄组最多,2059例(86.66%);男性病例多于女性,性别比为1.53∶1。职业分布以离退休人员、家务待业和工人为主达1608例(67.68%);建立灰色模型GM(1,1)方程为:Y(t+1)=141.25e^0.13t-117.38,其中待定参数μ=15.26,α=-0.13,模型拟合评价指标后验差比值C=0.24,小误差概率P=1,拟合精度好,外推预测出2018年、2019年莲湖区丙肝发病率分别为60.78/10万、68.96/10万。结论2008-2017年莲湖区丙肝发病总体呈上升趋势;根据GM(1,1)模型拟合评价指标,此模型对该区丙肝发病率的预测效果较好,且预测结果显示2018年、2019年丙肝发病率将持续升高。

熊猫索桥技术中两种高强度缝线修复跟腱断裂的生物力学比较研究

目的比较熊猫索桥技术(panda rope bridge technique,PRBT)中两种高强度缝线以不同缝合方式修复跟腱断裂的生物力学差异,以期为临床选择缝线及缝合方式提供参考。方法取市售40条牛跟腱随机分成4组(n=10),在跟腱止点近端4 cm处横形切断并缝合。其中,A、B组使用Ethibond 5号线,近端均为腱腹交界处Krackow缝合,远端分别为跟骨冠状孔固定、跟骨锚钉缝合,断端平面分别经过4、8根线;C、D组均使用Ultrabraid 2号线,近端为腱腹交界处Krackow缝合,远端为带线锚钉固定于跟骨,断端平面分别经过4、8根线。使用电子动静态万能材料仪测试动态拉力20~100、20~200、20~300、20~400 N(0.5 Hz、250个循环)下,每个阶段跟腱断端间隙以及缝合失效发生情况。结果拉力20~100 N和20~200 N,跟腱断端间隙从小到大依次为D、B、C、A组,其中A、B组间及C、D组间差异有统计学意义(P<0.05)。拉力20~300 N和20~400 N,4组跟腱断端间隙>5 mm,为巨大间隙。拉力20~100 N和20~200 N,4组缝合保持率均为100%。拉力20~300 N,A、B、C、D组缝合保持率分别为0、80%、60%和100%。其中,A组缝合保持率与B、D组间比较,差异有统计学意义(P<0.05);其余组间差异无统计学意义(P>0.05)。拉力20~400 N,A、B、C、D组缝合保持率分别为0、50%、0和70%,A、B组间及C、D组间比较差异有统计学意义(P<0.05)。结论采用PRBT以8根高强度缝线经跟腱断端平面方式修复跟腱断裂,可以满足早期快速康复中使用跟腱靴或者跟垫时安全行走的要求。

Controllable Fe/HCS catalysts in the Fischer-Tropsch synthesis: Effects of crystallization time

The Fischer--Tropsch synthesis(FTS)con-tinues to be an attractive alternative for producing a broad range of fuels and chemicals through the conversion of syngas(H2 and CO),which can be derived from various sources,such as coal,natural gas,and biomass.Among iron carbides,Fe2C,as an active phase,has barely been studied due to its thermodynamic instability.Here,we fabricated a series of Fe2C embedded in hollow carbon sphere(HCS)catalysts.By varying the crystallization time,the shell thickness of the HCS was manipulated,which significantly influenced the catalytic performance in the FTS.To investigate the relationship between the geometric structure of the HCS and the physic-chemical properties of Fe species,transmission electron microscopy,X-ray diffraction,N2 physical adsorption,X-ray photo-electron spectroscopy,hydrogen temperature-programmed reduction,Raman spectroscopy,and Mossbauer spectro-scopy techniques were employed to characterize the catalysts before and after the reaction.Evidently,a suitable thickness of the carbon layer was beneficial for enhancing the catalytic activity in the FTS due to its high porosity,appropriate electronic environment,and relatively high Fe2C content.

Glycoside-specific metabolomics combined with precursor isotopic labeling for characterizing plant glycosyltransferases

Glycosylation by uridine diphosphate-dependent glycosyltransferases(UGTs)in plants contributes to the complexity and diversity of secondary metabolites.UGTs are generally promiscuous in their use of acceptors,making it challenging to reveal the function of UGTs in vivo.Here,we described an approach that combined glycoside-specific metabolomics and precursor isotopic labeling analysis to characterize UGTs in Arabidopsis.We revisited the UGT72E cluster,which has been reported to catalyze the glycosylation of monolignols.Glycoside-specific metabolomics analysis reduced the number of differentially accumulated metabolites in the ugt72e1e2e3 mutant by at least 90%compared with that from traditional untargeted metabolomics analysis.In addition to the two previously reported monolignol glycosides,a total of 62 glycosides showed reduced accumulation in the ugt72e1e2e3 mutant,22 of which were phenylalanine-derived glycosides,including 5-OH coniferyl alcohol-derived and lignan-derived glycosides,as confirmed by isotopic tracing of[^(13)C_(6)]-phenylalanine precursor.Our method revealed that UGT72Es could use coumarins as substrates,and genetic evidence showed that UGT72Es endowed plants with enhanced tolerance to low iron availability under alkaline conditions.Using the newly developed method,the function of UGT78D2 was also evaluated.These case studies suggest that this method can substantially contribute to the characterization of UGTs and efficiently investigate glycosylation processes,the complexity of which have been highly underestimated.

Pd(OAc)_(2)/PPh_(3)-Catalyzed Desulfonylative Homocoupling of Arylsulfonyl Chlorides

The Pd-catalyzed homodimerization with respect to arylsulfonyl chlorides as an efficient method for the synthesisof biaryls has been developed. This desulfonylative reaction which was performed at reflux in 1,4-dioxane for 4h under air afforded the desired products in good to excellent yields.