Reconfigurable logic and in-sensor encryption operations in an asymmetrically tunable van der Waals heterostructure

Reconfigurable devices can be used to achieve multiple logic operation and intelligent optical sensing with low power consumption,which is promising candidates for new generation electronic and optoelectronic integrated circuits.However,the versatility is still limited and need to be extended by the device architectures design.Here,we report an asymmetrically gate two-dimensional(2D)van der Waals heterostructure with hybrid dielectric layer SiO_(2)/hexagonal boron nitride(h-BN),which enable rich function including reconfigurable logic operation and in-sensor information encryption enabled by both volatile and non-volatile optoelectrical modulation.When the partial gate is grounded,the non-volatile light assisted electrostatic doping endowed partially reconfigurable doping between n-type and p-type,which allow the switching of logic XOR and not implication(NIMP).When the global gate is grounded,additionally taking the optical signal as another input signal,logic AND and OR is realized by combined regulation of the light and localized gate voltage.Depending on the high on/off current ratio approaching 105 and reliable&switchable logic gate,in-sensor information encryption and decryption is demonstrated by manipulating the logic output.Hence,these results provide strong extension for current reconfigurable electronic and optoelectronic devices.

Tenecteplase thrombolysis for stroke up to 24 hours after onset with perfusion imaging selection:the umbrella phase IIa CHABLIS-T randomised clinical trial

Background The performance of intravenous tenecteplase in patients who had an acute ischaemic stroke with large/medium vessel occlusion or severe stenosis in an extended time window remains unknown. We investigated the promise of efficacy and safety of different doses of tenecteplase manufactured in China, in patients who had an acute ischaemic stroke with large/ medium vessel occlusion beyond 4.5- hour time window. Methods The CHinese Acute tissue- Based imaging selection for Lysis In Stroke- Tenecteplase was an investigator- initiated, umbrella phase IIa, open- label, blinded- endpoint, Simon’s two- stage randomised clinical trial in 13 centres across China's Mainland. Participants who had salvageable brain tissue on automated perfusion imaging and presented within 4.5-24 hours from time of last seen well were randomised to receive 0.25 mg/ kg tenecteplase or 0.32 mg/kg tenecteplase, both with a bolus infusion over 5-10 s. The primary outcome was proportion of patients with promise of efficacy and safety defined as reaching major reperfusion without symptomatic intracranial haemorrhage at 24-48 hours after thrombolysis. Assessors were blinded to treatment allocation. All participants who received tenecteplase were included in the analysis. Results A total of 86 patients who had an acute ischaemic stroke identified with anterior large/medium vessel occlusion or severe stenosis were included in this study from November 2019 to December 2021. All of the 86 patients enrolled either received 0.25 mg/kg (n=43) or 0.32 mg/kg (n=43) tenecteplase, and were available for primary outcome analysis. Fourteen out of 43 patients in the 0.25 mg/kg tenecteplase group and 10 out of 43 patients in the 0.32 mg/kg tenecteplase group reached the primary outcome, providing promise of efficacy and safety for both doses based on Simon’s two- stage design. Discussion Among patients with anterior large/medium vessel occlusion and significant penumbral mismatch presented within 4.5-24 hours from time of last seen well, tenecteplase 0.25 mg/kg and 0.32 mg/kg both provided sufficient promise of efficacy and safety.

Transition-metal and base-free ether synthesis via alcohol-participated yne-allylic substitution

Ethers are among the most important chemicals in organic synthesis,the pharmaceutical industry,agrochemical production,and material science.C–O bond formation via substitution is one of the most widely used strategies for ether formation.However,known methods usually employ transition-metal and bases to facilitate the process.In this work,we describe the base-and transition-metal-free ether formation via alcohol and phenol-participated substitution.The protocol allows access to a large number of ethers with enyne functional moieties,and features mild reaction conditions,high efficiency,and good regio-and stereoselectivities.The reaction could be readily scaled up,and the products could be used in a range of further transformations.

Numerical analysis on combustion characteristics of hybrid rocket motor with star-tube segmented grain

A method of star-tube combined segmented grain is proposed to improve the combustion performance of hybrid rocket motor.The star-tube combined segmented grain consists of a single-port star part and a single-port tube part.A mid-chamber forms between the fore-grain and the aft-grain for better mixing effect.The single-port feature gives hybrid rocket motor several advantages,such as simple structure,high reliability,and variable combinations.This paper is mainly aimed at studying the combustion characteristics of hybrid rocket motor with star-tube segmented grain through three-dimensional steady simulations.Combustion performance of the motors with different segmented grain combinations,including fore-tube/aft-tube,fore-tube/aftstar,fore-star/aft-star and fore-star/aft-tube,is contrastively analyzed.The motor in this paper adopts polyethylene and 90%hydrogen peroxide as the propellants.Simulations reveal that segmented grain with different-type grain combinations could greatly change the flow field in the second half of the combustion chamber.Transformation of the flow field is beneficial to the mixing between the fuel and the oxidizer,and it could increase the fuel regression rate and the combustion efficiency.The turbulence effect of tube aft-grain is better than that of star aft-grain.Among the four segmented grain combinations,the combination of star fore-grain and tube aft-grain is the preferred method with optimal overall performance.This grain configuration could increase the regression rate of tube aft-grain to surpass that of star aft-grain in other combinations.Besides,hybrid rocket motor with this grain configuration achieves the highest combustion efficiency.

环境DNA技术与传统捕捞揭示崇明岛内河鱼类多样性

崇明岛位于长江入海口,其内河网密布,鱼类资源众多,但违规捕捞现象屡禁不止,严重影响崇明岛鱼类资源。鱼类多样性是水生态环境保护的一个重要指标,为评估上海崇明岛内鱼类资源、揭示鱼类多样性,于2020年6月至2021年5月在崇明岛内河设置24个采样位点,利用环境DNA(eDNA)技术与传统捕捞手段,每个季度进行了1次共4次采样调查。调查共检出13个目级阶元的78种鱼类,其中鲤形目最多,约占44%。基于捕获鱼类样本计算的全年香农-威纳多样性指数为2.08,基于eDNA数据计算的全年香农-威纳样性指数值为2.96,表明崇明岛具有较丰富的鱼类多样性。两种方法检测出共同的优势种为鳊(Parabramis pekinensis)、似鳊(Pseudobrama simoni)、麦穗鱼(Pseudorasbora parva)、子陵吻虾虎鱼(Rhinogobius giurinus)、大鳍(Acheilognathus macropterus),表明崇明岛内河鱼类群落结构由淡水鱼类主导。主坐标分析和PERMANOVA检验结果显示东-西部群落鱼类组成存在差异(R2=0.101 2,P=0.027 6)。研究结果亦表明eDNA技术可以作为传统鱼类资源调查的一个重要辅助手段。本研究为崇明岛内河鱼类资源现存状况、合理利用及保护提供了基础资料。

Conserved Cytochrome P450 Evolved in Seed Plants Regulates Flower Maturation

Global inspection of plant genomes identifies genes maintained in low copies across taxa and under strong purifying selection, which are likely to have essential functions. Based on this rationale, we investigated the function of the low-duplicated CYP715 cytochrome P450 gene family that appeared early in seed plants and evolved under strong negative selection. Arabidopsis CYP715A 1 showed a restricted tissue-specific expres- sion in the tapetum of flower buds and in the anther filaments upon anthesis, cyp715a1 insertion lines showed a strong defect in petal development, and transient alteration of pollen intine deposition. Comparative expres- sion analysis revealed the downregulated expression of genes involved in pollen development, cell wall biogenesis, hormone homeostasis, and floral sesquiterpene biosynthesis, especially TPS21 and several key genes regulating floral development such as MYB21, MYB24, and MYC2. Accordingly, floral sesquiterpene emission was suppressed in the cyp715a1 mutants. Flower hormone profiling, in addition, indicated a modi- fication of gibberellin homeostasis and a strong disturbance of the turnover of jasmonic acid derivatives. Petal growth was partially restored by the active gibberellin GA3 or the functional analog of jasmonoyl-isoleucine, coronatine. CYP715 appears to function as a key regulator of flower maturation, synchronizing petal expan- sion and volatile emission. It is thus expected to be an important determinant of flower-insect interaction.

Copper-catalyzed diversified annulations betweenα-diketones and alkynylα-diketones

Copper-catalyzed divergent annulations betweenα-diketones and alkynylα-diketones have been achieved,delivering a series of highly functionalized and biologically important cis-hexahydro-2Hcyclopenta[b]furan(HCPF)and 2-hydroxydihydrofuran-3(2H)-one(HDFO)products with high levels of stereoselectivity under identical conditions.The protocol features the use of earth-abundant copper catalyst,mild conditions,shortening synthetic routes in constructing different molecular frameworks,and reducing the corresponding possible waste production.The substituents of the nucleophilicα-diketones play crucial roles in switching the reaction pathways.

Catalytic chemodivergent annulations betweenα-diketones and alkynylα-diketones

Four types of unprecedented and chemodivergent reactions betweenα-diketones and alkynylα-diketones have been achieved under the catalysis of phosphine and Br?nsted base,respectively,leading to the rapid construction of four different classes of biologically important but synthetically challenging molecular scaffolds including 2-hydroxyfuran-3(2H)-ones,4-hydroxy-2-oxabicyclo[2.2.1]heptan-3-ones,1,3-diaryl cyclobutanes,and 4-(furan-2(3H)-ylidene)cyclopent-2-enones.The formation of the products includes two novel rearrangement processes,and further transformations on the products can be easily achieved to deliver value-added substances such as highly functionalized cyclopentanes.Moreover,the 2-hydroxyfuran-3(2H)-one products display promising photophysical properties such as green luminescence under UV light and aggregation-induced emission effect,showing the practical application value of this work.The great potential ofα-diketones in both synthetic chemistry and material science has been unambiguously demonstrated.