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1NPR1 as a transgenic crop protection strategy in horticultural species显示文摘The NPR1(NONEXPRESSOR OF PATHOGENESIS RELATED GENES1)gene has a central role in the long-lasting,broad-spectrum defense response known as systemic acquired resistance(SAR).When overexpressed in a transgenic context in Arabidopsis thaliana,this gene enhances resistance to a number of biotic and abiotic stresses.Its position as a key regulator of defense across diverse plant species makes NPR1 a strong candidate gene for genetic engineering disease and stress tolerance into other crops.High-value horticultural crops face many new challenges from pests and pathogens,and their emergence exceeds the pace of traditional breeding,making the application of NPR1-based strategies potentially useful in fruit and vegetable crops.However,plants overexpressing NPR1 occasionally present detrimental morphological traits that make its application less attractive.The practical utility of NPR-based approaches will be a balance of resistance gains versus other losses.In this review,we summarize the progress on the understanding of NPR1-centered applications in horticultural and other crop plants.We also discuss the effect of the ectopic expression of the A.thaliana NPR1 gene and its orthologs in crop plants and outline the future challenges of using NPR1 in agricultural applications.Katchen Julliany P.Silva Nasser Mahna Zhonglin Mou Kevin M.Folta 2018Horticulture Research2018,5,1:3
2Self-assembly of single walled carbon nanotubes onto cotton to make conductive yarn显示文摘A simple,economical and scalable technique is demonstrated to make conductive yarn.Single walled carbon nanotubes(SWCNTs)are non-covalently functionalized with dye(Acid Red 91)and dispersed in water;while cotton yarn is treated with poly(ethylene imine).When the resulting yarn is immersed in the SWCNT dispersion,SWCNTs self-assemble onto the yarn due to electrostatic forces between the functionalized nanotubes and yarn.Scanning electron microscopy,transmission electron microscopy and Raman spectroscopy indicate the assembly of carbon nanotubes.The SWCNT functionalized yarn exhibits reasonable electrical conduction behaviour and are then used to make chemiresistors.The electrical resistance of the chemiresistors used as sensors increases on exposure to ammonia gas,which can be explained in terms of electron transfer between gas molecules and SWCNTs.Wei Zhang Yee Yuan Tan Chengwei Wu S.Ravi P.Silva 2012Particuology2012,10,4:2
3Microstructural Morphologies and Experimental Growth Laws during Solidification of Monotectic and Hypermonotectic Al-Pb Alloys显示文摘Al—Pb alloys with monotectic and hypermonotectic compositions were directionally solidified under unsteadystate heat flow conditions.The cooling curves recorded during solidification allowed solidification thermal parameters such as the cooling rate(T),growth rate(v) and thermal gradient(G) to be experimentally determined.Different microstructural patterns have been associated with the alloy solute content,i.e.,Al—1.2and 2.1 wt%Pb.A sequence of morphologies from the bottom to the top of the Al—1.2 wt%Pb alloy casting(monotectic) can be observed:Pb-rich droplets in the aluminum-rich matrix,followed by a region of microstructural transition formed by droplets and fibers and finally by a mixture of fibers and strings of pearls.A completely fibrous structure(without transition) has been observed along the entire Al—2.1 wt%Pb alloy casting(hypermonotectic).The interphase spacing(λ) was measured along the casting length,and experimental correlations between λ and experimental solidification thermal parameters have been established.Power laws with a —2.2 exponent expressing λ as a function of the growth rate,v,were found to better represent the fibrous growth of both Al—Pb alloys.Moreover,a single experimental law expressing λ as a function of both G and v was found to describe the fibrous growth of both the monotectic and the hypermonotectic alloys experimentally examined.Adrina P.Silva Amauri Garcia José E.Spinelli 2014Journal of Materials Science & Technology2014,30,4:2
4Antiglycation,antioxidant,antiacne,and photoprotective activities of crude extracts and triterpene saponin fraction of Sapindus saponaria L.fruits:An in vitro study显示文摘Objective:To evaluate the photoprotective,antioxidant,antiglycation,and antiacne activities of crude extract(CESs)and triterpene saponin fraction(TSSs)of Sapindus saponaria.Methods:HPLC-MS purification was performed on a Symmetry TM C18 column.The saponins were identified by a UV detector.Antioxidant activity was evaluated by DPPH and O_(2)^(−)radicals scavenging,and FRAP and TBARS assays.Glycation activity was assessed by relative electrophoretic mobility and inhibition of advanced glycation end products(AGEs)formation.Additionally,antiacne activity was determined by inhibition of Cutibacterium acnes,and photoprotective effect was evaluated by Mansur’s method.Results:Most of the triterpene saponins detected in the fraction by HPLC-MS analysis were hederagenin as the aglycon.CESs and TSSs presented varying antioxidant activity in DPPH(CESs:75.69%and TSSs:83.65%),FRAP(CESs:425.39μM TE/g DW and TSSs:649.36μM TE/g DW),TBARS(CESs:42.96%and TSSs:52.16%)and O_(2)^(−)radicals scavenging(CESs:61.33%and TSSs:86.69%)tests.CESs and TSSs also exhibited antiglycation activity comparable to bovine serum albumin treated with aminoguanidine.In addition,CESs and TSSs showed inhibition of AGE formation(34.48%and 61.85%,respectively).Antiacne activity against Cutibacterium acnes was observed with a minimum inhibitory concentration equal to minimum bactericidal concentration(CESs:36.11µg/mL and TSSs:18.34µg/mL).In photoprotective assays,CESs and TSSs showed maximum absorbance of 1.42 to 0.20 and 2.80 to 1.30,respectively,in the wavelength range of 260 to 400 nm.Furthermore,CESs and TSSs showed sun protection factors of 8.89 and 14.89,respectively.Conclusions:Sapindus saponaria fruit extracts show strong antioxidant potential and antiglycation activity against bovine serum albumin glycation and AGE formation.Besides,they presented antibacterial activity against Cutibacterium acnes and photoprotective effect against UV-A and UV-B.Regildo M.G.Silva Gustavo R.Martins Laura M.B.Nucci Filipe O.Granero Célia C.M.Figueiredo Patrícia S.Santiago Luciana P.Silva 2022Asian Pacific Journal of Tropical Biomedicine2022,12,9:1
5Complex permittivity-dependent plasma confinement-assisted growth of asymmetric vertical graphene nanofiber membrane for high-performance Li-S full cells显示文摘Vertical graphene(VG),possessing superior chemical,physical,and structural peculiarities,holds great promise as a building block for constructing a high-energy density lithium-sulfur(Li-S)battery.Therefore,it is desirable to develop a new VG growth technique with a novel structure to enable wide applications.Herein,we devise a novel complex permittivity-dependent plasma confinement-assisted VG growth technique,via asymmetric growing a VG layer on one side of N-doped carbon nanofibers for the first time,using a unique lab-built high flux plasma-enhanced chemical vapor deposition system,as a bifunctional nanofiber membrane to construct Li-S batteries with low neg-ative/positive(N/P)and electrolyte/sulfur(E/S)ratios.The unique nanofiber membrane could simultaneously protect the cathode and anode,enabling an excellent electrochemical performance with low N/P and E/S ratios in Li-S bat-teries.Such a full cell delivers high gravimetric energy density and volumetric energy density of 340 Wh kg^(-1) and 547 Wh L^(-1),respectively,at low N/P(2:1)and E/S(4:1)ratios.Furthermore,a pouch cell achieves a high areal capacity of 7.1 mAh cm^(-2) at a sulfur loading of 6 mg cm^(-2).This work put forward a novel pathway for the design of high-energy density Li-S batteries.Yongshang Zhang Zhiheng Wu Shaobin Wang Neng Li S.Ravi P.Silva Guosheng Shao Peng Zhang 2022InfoMat2022,4,7:1
6mTOR pathway activation in cutaneous melanoma is associated with poorer prognosis characteristics显示文摘H.Pópulo P.Soares A.Faustino A. S.Rocha P.Silva F.Azevedo J. M.Lopes 2011Pigment Cell & Melanoma Research2011,,:1
7Laser-Induced Recoverable Fluorescence Quenching of Perovskite Films at a Microscopic Grain Scale显示文摘Understanding the fundamental properties of metal-halide perovskite materials is driving the development of novel optoelectronic applications.Here,we report the observation of a recoverable laser-induced fluorescence quenching phenomenon in perovskite films with a microscopic grain-scale restriction,accompanied by spectral variations.This fluorescence quenching depends on the laser intensity and the dwell time under Auger recombination dominated conditions.These features indicate that the perovskite lattice deformation may take the main responsibility for the transient and show a new aspect to understand halide perovskite photostability.We further modulate this phenomenon by adjusting the charge carrier recombination and extraction,revealing that efficient carrier transfer can improve the bleaching resistance of perovskite grains.Our results provide future opportunities to attain high-performance devices by tuning the perovskite lattice disorder and harvesting the energetic carriers.Yuren Xiang Yameng Cao Wenqiang Yang Rui Hu Sebastian Wood Bowei Li Qin Hu Fan Zhang Jujie He Mozhgan Yavari Jinlai Zhao Yunlong Zhao Jun Song Junle Qu Rui Zhu Thomas P.Russell S.Ravi P.Silva Wei Zhang 2022Energy & Environmental Materials2022,5,4:0
8CO_(2)Emissions Post-COP26:Who is Responsible to Curb the Flow?Does it Matter if We Can Make it a Win-Win?显示文摘The debate about climate change is highly politicized.Not everyone is convinced that CO_(2)emissions are worth curbing despite seemingly irrefutable evidence in the IPCC’s latest report.[1]Some have vested interests in exploiting fossil fuels while others think alternative,cheaper solutions can be found.Countries that have shifted from manufacturing to service-based economies will find it easier to decarbonize.Other countries with relatively low carbon emissions per capita but large populations believe it is unfair that they should have to bear heavy costs of decarbonization to solve a problem that wealthier countries have created.James Crawshaw S.Ravi P.Silva 2022Energy & Environmental Materials2022,5,3:0
9Horizontally Solidified Al-3 wt%Cu-(0.5 wt%Mg)Alloys:Tailoring Thermal Parameters,Microstructure,Microhardness,and Corrosion Behavior显示文摘In the present experimental investigation,Al–3 wt%Cu and Al–3 wt%Cu–0.5 wt%Mg alloys castings are produced by a horizontal solidification technique with a view to examining the interrelationship among growth rate(GR),cooling rate(CR),secondary dendrite arm spacing(λ2),Vickers microhardness(HV),and corrosion behavior in a 0.5 M NaCl solution.The intermetallic phases of the as-solidified microstructures,that is,h-Al2Cu,S–Al2CuMg,and x-Al7Cu2 Fe,are subjected to a comprehensive characterization by using calculations provided by computational thermodynamics software,optical microscopy,and scanning electron microscopy/energy-dispersive spectroscopy.Moreover,electrochemical impedance spectroscopy and potentiodynamic polarization tests have been applied to analyze the corrosion performance of samples of both alloys castings.Hall–Petch-type equations are proposed to represent the HV dependence onλ2.It is shown that the addition of Mg to the Al–Cu alloy has led to a considerable increase in HV;however,the Al–Cu binary alloy is shown to have lower corrosion current density(icorr)as well as higher polarization resistance as compared to the corresponding results of the Al–Cu–Mg ternary alloy.Andre Barros Clarissa Cruz Adrina P.Silva Noe Cheung Amauri Garcia Otavio Rocha Antonio Moreira 2019Acta Metallurgica Sinica(English Letters)2019,32,6:0
10Zinc-Based Metal-Organic Frameworks for High-Performance Supercapacitor Electrodes:Mechanism Underlying Pore Generation显示文摘Heat treatment of metal-organic frameworks(MOFs)has provided a wide variety of functional carbons coordinated with metal compounds.In this study,two kinds of zinc-based MOF(ZMOF),C_(16)H_(10)O_(4)Zn(ZMOF1)and C_(8)H_(4)O_(4)Zn(ZMOF2),were prepared.ZMOF1 and ZMOF2 were carbonized at 1000℃,forming CZMOF1 and CZMOF2,respectively.The specific surface area(S_(BET))of CZMOF2 was~2700 m^(2)g^(−1),much higher than that of CZMOF1(~1300 m^(2)g^(−1)).A supercapacitor electrode based on CZMOF2 achieved specific capacitances of 360,278,and 221 F g^(−1)at 50,250,and 1000 mA g^(−1)in an aqueous electrolyte(H2SO_(4)),respectively,the highest values reported to date for ZMOF-derived electrodes under identical conditions.The practical applicability of the CZMOF-based supercapacitor was verified in non-aqueous electrolytes.The initial capacitance retention was 78%after 100000 charge/discharge cycles at 10 A g^(−1).Crucially,the high capacitance of CZMOF2 arises from pore generation during carbonization.Below 1000℃,pore generation is dominated by the Zn/C ratio of ZMOFs,as carbon atoms reduce the zinc oxides formed during carbonization.Above 1000℃,a high O/C ratio becomes essential for pore generation because the oxygen functional groups are pyrolyzed.These findings will provide insightful information for other metal-based MOFderived multifunctional carbons.Shigeyuki Umezawa Takashi Douura Koji Yoshikawa Daisuke Tanaka Vlad Stolojan S.Ravi P.Silva Mika Yoneda Kazuma Gotoh Yasuhiko Hayashi 2023Energy & Environmental Materials2023,6,2:0
11Progress of Pb-Sn Mixed Perovskites for Photovoltaics: A Review显示文摘Pb-Sn mixed perovskites are becoming increasingly popular as narrowbandgap(1.2–1.3 eV)light absorbers in single-junction perovskite solar cells(PSCs)and as bottom cells for all-perovskite tandem solar cells,for highefficiency,low-cost,lightweight,roll-to-roll printable photovoltaic(PV)applications.From the first report of planar Pb:Sn mixed PSCs in 2014,the power conversion efficiencies(PCE)have increased from 10%to 21%by the end of 2020 with an exponential growth in research conducted in this field.Despite much effort,the performance and stability of Pb-Sn mixed PSCs are still limited,which constrains their long-term use in all-perovskite tandem devices.This review highlights the avenues explored in improving different aspects of Pb-Sn mixed PSCs and provides a comprehensive discussion of the interdependent factors affecting the device performance.This includes compositional engineering of the perovskite crystal,absorber layer fabrication and crystallization methods,bandgap tuning,Sn4+reduction,and surface passivation of the absorber layer,as well as the selection of interlayers and electrodes of the final PSC.Rajapakshe Mudiyanselage Indrachapa Bandara Shashini M.Silva Cameron C.L.Underwood K.D.G.Imalka Jayawardena Radu A.Sporea S.Ravi P.Silva 2022Energy & Environmental Materials2022,5,2:0
12Degradation Diagnostics from the Subsurface of Lithium-Ion Battery Electrodes显示文摘Despite the long-established rocking-chair theory of lithium-ion batteries(LIBs),developing novel characterization methodology with higher spatiotemporal resolution facilitates a better understanding of the solid electrolyte interphase studies to shape the reaction mechanisms.In this work,we develop a Xenon ion plasma focused ion beam(Xe+PFIB)-based characterization technique to probe the cross-sectional interface of both ternary cathode and graphite anode electrodes,with the focus on revealing the chemical composition and distribution underneath the electrode surface by in-depth analysis of secondary ions.Particularly,the lithium fluoride is detected in the pristine cathode prior to contact with the electrolyte,reflecting that the electrode degradation is in the form of the loss of lithium inventory during electrode preparation.This degradation is related to the hydrolysis of the cathode material and the decomposition of the PVDF binder.Through the quantitative analysis of the transition-metal degradation products,manganese is found to be the dominant element in the newly formed inactive fluoride deposition on the cathode,while no transition metal signal can be found inside the anode electrode.These insights at high resolution implemented via a PFIB-based characterization technique not only enrich the understanding of the degradation mechanism in the LIBs but also identify and enable a high-sensitivity methodology to obtain the chemical survey at the subsurface,which will help remove the capacity-fade observed in most LIBs.Xuhui Yao Tomas Samoril JiriDluhos John F.Watts Zhijia Du Bohang Song SRavi P.Silva Tan Sui Yunlong Zhao 2022Energy & Environmental Materials2022,5,2:0
13Influence of Halide Choice on Formation of Low-Dimensional Perovskite Interlayer in Efficient Perovskite Solar Cells显示文摘Recent advances in heterojunction and interfacial engineering of perovskite solar cells(PSCs)have enabled great progress in developing highly efficient and stable devices.Nevertheless,the effect of halide choice on the formation mechanism,crystallography,and photoelectric properties of the lowdimensional phase still requires further detailed study.In this work,we present key insights into the significance of halide choice when designing passivation strategies comprising large organic spacer salts,clarifying the effect of anions on the formation of quasi-2D/3D heterojunctions.To demonstrate the importance of halide influences,we employ novel neo-pentylammonium halide salts with different halide anions(neoPAX,X=I,Br,or Cl).We find that regardless of halide selection,iodide-based(neoPA)_(2)(FA)_((n-1))PbnI_((3n+1))phases are formed above the perovskite substrate,while the added halide anions diffuse and passivate the perovskite bulk.In addition,we also find the halide choice has an influence on the degree of dimensionality(n).Comparing the three halides,we find that chloride-based salts exhibit superior crystallographic,enhanced carrier transport,and extraction compared to the iodide and bromide analogs.As a result,we report high power conversion efficiency in quasi-2D/3D PSCs,which are optimal when using chloride salts,reaching up to 23.35%,and improving long-term stability.Xueping Liu Thomas Webb Linjie Dai Kangyu Ji Joel A.Smith Rachel C.Kilbride Mozhgan Yavari Jinxin Bi Aobo Ren Yuanyuan Huang Zhuo Wang Yonglong Shen Guosheng Shao Stephen J.Sweeney Steven Hinder Hui Li David G.Lidzey Samuel D.Stranks Neil C.Greenham S.Ravi P.Silva Wei Zhang 2022Energy & Environmental Materials2022,5,2:0
14A functional gel polymer electrolyte based on PVDF-HFP/gelatin toward dendrite-free lithium metal batteries显示文摘The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved the safety of traditional LMBs.However,the limited inhibition of GPE on lithium dendrites is detrimental to the safety of LMBs.Herein,a kind of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)/gelatin(GN)GPE with high ionic conductivity,high-temperature resistance,and flame-retardancy,was prepared by electrospinning and soaking method.Utilizing the electrospinning network of PVDF-HFP,its affinity to liquid electrolytes,makes this GPE more beneficial to ions transport and the formation of gel.And,the GN with sol–gel properties,enhances the mechanical property(13.5 MPa)of HFP-GN GPE.Meanwhile,X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)suggest that the attraction of polar groups of GN to Li+can regulate the distribution of Li+and protect Li anodes.Consequently,the application of HFP-GN GPEs to LMBs with cathodes of LiFePO_(4) and LiCoO_(2) deliver excellent electrochemical performances:after 300 cycles,the LiFePO_(4)/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09%at 5 C;after 400 cycles at 2 C,the LiCoO_(2)/HFP-GN GPE/Li cell retains a high capacity retention of 74%.This GPE is demonstrated for the application prospect of safe LMBs.Xiaoyi Hu Kangli Liu Shijie Zhang Guosheng Shao S.Ravi P.Silva Peng Zhang 2024Nano Research2024,17,4:0
15Effect of Surfactants on the Thermoelectric Performance of Double-Walled Carbon Nanotubes显示文摘Thermoelectrics are a promising solution to the recovery of some of the 60%of the worldwide energy wasted as heat.However,their conversion efficiency is low and the best performing materials are brittle,toxic,and made of expensive ceramics.The challenge in developing better performing materials is in disrupting the electrical vs thermal conductivity correlation,to achieve low thermal conductivity simultaneously with a high electrical conductivity.Carbon nanotubes allow for the decoupling of the electronic density of states from the phonon density of states and this paper shows that flexible,thin films of double-walled carbon nanotube(DWCNT)can form effective n-and p-doped semiconductors that can achieve a combined Seebeck coefficient of 157.6µV K^(−1),the highest reported for a single DWCNT device to date.This is achieved through selected surfactant doping,whose role is correlated with the length of the hydrocarbon chain of the hydrophobic tail group of the surfactant’s molecules.CNTs functionalized with Triton X-405 show the highest output power consisting of a single junction of p-and n-type thermoelectric elements,reaching as high as 67 nW for a 45 K temperature gradient.Thus enabling flexible,cheaper,and more efficient thermoelectric generators through the use of functionalized CNTs.Zakaria Saadi Simon G.King Jose V.Anguita Vlad Stolojan S.Ravi P.Silva 2023Energy & Environmental Materials2023,6,1:0
16Fern extracts potentiate fluconazole activity and inhibit morphological changes in Candida species显示文摘Objective: To investigate the antifungal activity of the fern species Lygodium venustum(L. venustum) and Pityrogramma calomelanos(P. calomelanos) against Candida albicans and Candida tropicalis strains.Methods: The microdilution method was used to evaluate the antifungal activity, as well as the modulating effects of ethanolic extracts of these plants in combination with fluconazole. The minimum inhibitory concentration(MIC), minimum fungicide concentration and morphological changes were also determined.Results: The extract obtained from L. venustum presented a MIC > 8 192 mg/m L, while the extract obtained from and P. calomelanos presented a MIC = 8 192 mg/m L, indicating that they present weak antifungal activity. However, combination of the extracts with Fluconazole potentiated the antifungal activity of this drug. At different experimental conditions, such as concentration of the extract and type of strain, the extracts inhibited hyphae and pseudohyphae formation, indicating that these fern species can affect the morphology of the fungi.Conclusions: The extracts obtained from the fern species L. venustum and P. calomelanos dose not present significant antifungal activity. However, P. calomelanos potentiates the activity of fluconazole and both extracts inhibits the morphological changes in Candida species, indicating that they have potential pharmacological activity as modulators of fungal biology. Therefore, novel studies are required to characterize the interference of these extracts in the virulence and pathogenicity of Candida species as well as the potential of fern species to treat fungal infections.Maria A.Freitas Antonia T.L.Santos Antonio J.T.Machado Ana Raquel P.Silva Fábia F.Campina Maria S.Costa Gioconda M.A.B.Martins Maria Flaviana B.Morais-Braga Saulo R.Tintino Irwin R.A.Menezes Jaime Ribeiro-Filho Altevir P.Medeiros Adeliana S.Oliveira Patrício B.Maracajá Henrique D.M.Coutinho 2017Asian Pacific Journal of Tropical Biomedicine2017,7,11:0
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