RESUMEN
Frankliniella occidentalis (Pergande) is a typical omnivorous insect that feeds on host plants, pollens and mite eggs, and poses a threat to crops worldwide. The insulin signalling pathway (ISP) is a typical nutrient-sensitive pathway that participates in the regulation of various functions in insects. Serine/threonine kinases (AKTs) and phosphoinositide-dependent kinases (PDKs) are key components of the ISP. In this study, the FoAKT and FoPDK genes in F. occidentalis were cloned, and the effects of three foods on their expression were determined. The expression of FoAKT and FoPDK in the thrips fed on kidney bean leaves supplemented with pine pollen or mite eggs was higher than in those primarily fed on leaves alone. Meanwhile, the fecundity of thrips fed on leaves supplemented with pine pollen was highest. In addition, RNA interference-mediated knockdown of FoAKT and FoPDK decreased vitellogenin (Vg) content and Vg expression in females, shortened ovariole length, delayed egg development and reduced fecundity and offspring hatching rates. Furthermore, the synthesis of juvenile hormone (JH) was reduced, and the contents of glucose, trehalose, glycogen and trehalase were affected. These results suggest that FoAKT and FoPDK regulate the reproduction of F. occidentalis by regulating Vg and JH production as well as carbohydrate metabolism.
Asunto(s)
Proteínas de Insectos , Reproducción , Thysanoptera , Animales , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Femenino , Thysanoptera/genética , Thysanoptera/fisiología , Polen , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Hormonas Juveniles/metabolismo , Ácaros/fisiología , FertilidadRESUMEN
Environmental exposures are the main cause of cancer, and their carcinogenicity has not been fully evaluated, identifying potential carcinogens that have not been evaluated is critical for safety. This study is the first to propose a weight of evidence (WoE) approach based on computational methods to prioritize potential carcinogens. Computational methods such as read across, structural alert, (Quantitative) structure-activity relationship and chemical-disease association were evaluated and integrated. Four different WoE approach was evaluated, compared to the best single method, the WoE-1 approach gained 0.21 and 0.39 improvement in the area under the receiver operating characteristic curve (AUC) and Matthew's correlation coefficient (MCC) value, respectively. The evaluation of 681 environmental exposures beyond IARC list 1-2B prioritized 52 chemicals of high carcinogenic concern, of which 21 compounds were known carcinogens or suspected carcinogens, and eight compounds were identified as potential carcinogens for the first time. This study illustrated that the WoE approach can effectively complement different computational methods, and can be used to prioritize chemicals of carcinogenic concern.
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Carcinógenos , Exposición a Riesgos Ambientales , Humanos , Carcinógenos/toxicidad , Exposición a Riesgos Ambientales/efectos adversos , Relación Estructura-Actividad Cuantitativa , Medición de Riesgo , AnimalesRESUMEN
The western flower thrips, Frankliniella occidentalis Pergande, is an invasive pest that damages agricultural and horticultural crops. The induction of plant defenses and RNA interference (RNAi) technology are potent pest control strategies. This study investigated whether the anti-adaptive ability of F. occidentalis to jasmonic acid (JA)- and methyl jasmonate (MeJA)-induced defenses in kidney bean plants was attenuated after glutathione S-transferase (GST) gene knockdown. The expression of four GSTs in thrips fed JA- and MeJA-induced leaves was analyzed, and FoGSTd1 and FoGSTs1 were upregulated. Exogenous JA- and MeJA-induced defenses led to increases in defensive secondary metabolites (tannins, alkaloids, total phenols, flavonoids, and lignin) in leaves. Metabolome analysis indicated that the JA-induced treatment of leaves led to significant upregulation of defensive metabolites. The activity of GSTs increased in second-instar thrips larvae fed JA- and MeJA-induced leaves. Co-silencing with RNAi simultaneously knocked down FoGSTd1 and FoGSTs1 transcripts and GST activity, and the area damaged by second-instar larvae feeding on JA- and MeJA-induced leaves decreased by 62.22% and 55.24%, respectively. The pupation rate of second-instar larvae also decreased by 39.68% and 39.89%, respectively. Thus, RNAi downregulation of FoGSTd1 and FoGSTs1 reduced the anti-adaptive ability of F. occidentalis to JA- or MeJA-induced defenses in kidney bean plants.
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Phaseolus , Thysanoptera , Acetatos , Animales , Ciclopentanos/metabolismo , Ciclopentanos/farmacología , Flavonoides/metabolismo , Flores/metabolismo , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Lignina/metabolismo , Oxilipinas/metabolismo , Oxilipinas/farmacología , Phaseolus/metabolismo , Fenoles/metabolismo , Interferencia de ARN , Taninos/metabolismo , Thysanoptera/genética , Thysanoptera/metabolismoRESUMEN
Two-dimensional (2D) materials, such as graphene, inorganic oxides, and hydroxides, are one of the most extensively studied classes of materials due to their unilamellar crystallites or nanosheet structures. In this study, instead of using the universal exfoliation method of the bulky crystal precursor, 2D crystals/nanosheets of MgAl-layered double hydroxides (LDHs) were synthesized in formamide. We propose that the obtained crystals are unilamellar according to the XRD, TEM, and AFM observations. The HRTEM and fast Fourier transform images confirm that the crystal structures are the same as those of the exfoliated MgAl-LDH nanosheets. The directly synthesized sheets can stack into a 3D crystal structure, which is the same as that of typical LDHs except for the disordered orientation of the a-/b- crystal axis of each sheet. This result provides not only a novel approach to the preparation of 2D crystals but also insight into the formation mechanism of LDHs.
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Lithium-sulfur batteries offer the potential for significantly higher energy density and cost-effectiveness. However, their progress has been hindered by challenges such as the "shuttle effect" caused by lithium polysulfides and the volume expansion of sulfur during the lithiation process. These limitations have impeded the widespread adoption of lithium-sulfur batteries in various applications. It is urgent to explore the high-performance sulfur host to improve the electrochemical performance of the sulfur electrode. Herein, bimetallic NiFe hydroxide (NiFe-LDH)-modified carbon nanotubes (CNTs) are prepared as the sulfur host materials (NiFe-CNT@S) for loading of sulfur. On the one hand, the crosslinked CNTs can increase the electron conductivity of the sulfur host as well as disperse NiFe-LDHs nanosheets. On the other hand, NiFe-LDHs command the capability of strongly adsorbing lithium polysulfides and also accelerate their conversion, which effectively suppresses the shuttle effect problem in lithium polysulfides. Hence, the electrochemical properties of NiFe-CNT@S exhibit significant enhancements when compared with those of the sulfur-supported pure NiFe-LDHs (NiFe-LDH@S). The initial capacity of NiFe-CNT@S is reported to be 1010 mAh g-1. This value represents the maximum amount of charge that the material can store per gram when it is first synthesized or used in a battery. After undergoing 500 cycles at a rate of 2 C (1 C = 1675 mA g-1), the NiFe-CNT@S composite demonstrates a sustained capacity of 876 mAh g-1. Capacity retention is a measure of how well a battery or electrode material can maintain its capacity over repeated charge-discharge cycles, and a higher retention percentage indicates better durability and stability of the material.
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Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is an agricultural pest threatening various horticultural crops worldwide. Inducing plant resistance is an ecologically beneficial and potentially effective method for controlling F. occidentalis. As an essential nutrient element, exogenous calcium enhances plant-induced resistance. This study investigated the effects of CaCl2 on the secondary metabolites of kidney bean plants and detoxifying and digestive enzymes in F. occidentalis. We found that treatment of plants and treatment time and also the interactions of the 2 factors significantly affected secondary metabolites contents (tannin, flavonoids, total phenol, alkaloid, and lignin) of kidney bean leaves, which indicated that that the effect of treatment of plants on secondary metabolites varied with treatment time. Moreover, when thrips fed on CaCl2-treated plants, the activities of detoxifying enzymes, enzymes glutathione S-transferase and cytochrome P450 substantially increased compared to those in which thrips fed on control plants. However, the activity of carboxylesterase significantly decreased. The detoxifying enzyme genes CL992.contig6, CYP4PN1, and CYP4PJ2 were significantly upregulated at 24 and 48 h. The activities of digestive enzymes (α-amylase, chymotrypsin, and lipase) increased substantially in F. occidentalis. The digestive enzyme gene, FoAMY-1, was significantly upregulated at 24 and 48 h after treatment. The pupation rate and pupal weight of F. occidentalis were significantly reduced. The results indicated that exogenous CaCl2-induced metabolic changes in kidney bean plants and altered the enzymatic activity and development of F. occidentalis that fed upon them.
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Phaseolus , Thysanoptera , Animales , Thysanoptera/fisiología , Calcio/farmacología , Cloruro de Calcio/farmacología , Productos AgrícolasRESUMEN
The most reported two-dimensional (2D) reconfigurable multivalued logic (RMVL) devices primarily involve a planar configuration and carrier transport, which limits the high-density circuit integration and high-speed logic operation. In this work, the vertical transistors with reconfigurable MoTe2 homojunction are developed for low-power, high-speed, multivalued logic circuits. Through top/bottom dual-gate modulation, the transistors can be configured into four modes: P-i-N, N-i-P, P-i-P, and N-i-N. The reconfigurable rectifying and photovoltaic behaviors are observed in P-i-N and N-i-P configurations, exhibiting ideal diode characteristics with a current rectification ratio over 105 and sign-reversible photovoltaic response with a photoswitching ratio up to 7.44 × 105. Taking advantage of the seamless homogeneous integration and short vertical channel architecture, the transistor can operate as an electrical switch with an ultrafast speed of 680 ns, surpassing the conventional p-n diode. The MoTe2 half-wave rectifier is then applied in high-frequency integrated circuits using both square wave and sinusoidal waveforms. By applying an electrical pulse with a 1/4 phase difference between two input signals, the RMVL circuit has been achieved. This work proposes a universal and reconfigurable vertical transistor, enabled by dual-gate electrostatic doping on top/bottom sides of MoTe2 homojunction, suggesting a high integration device scheme for high-speed RMVL circuits and systems.
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As advanced electrodes for direct alcohol fuel cells, graphene-Pd and graphene-Pt composites with a trace of SnO(2) have been successfully synthesized by a modified electroless plating technique. The surface of graphene oxide is first sensitized by Sn(2+) ions, and subsequently, Pd or Pt nanoparticles are deposited on the surface of graphene oxide. Finally, graphene oxide was reduced to graphene by further adding NaBH(4). Compared to other carbon-(e.g., Vulcan XC-72R) supported Pd and Pt, the resultant graphene-Pd and Pt composites exhibit better electrocatalytic activity and long-term stability toward alcohol electrooxidation. Additionally, a trace amount of SnO(2) formed around active catalysts may also be beneficial to the enhancement of electrochemical activity.
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Alcoholes/química , Técnicas Electroquímicas , Grafito/química , Paladio/química , Platino (Metal)/química , Catálisis , Electrodos , Oxidación-Reducción , Tamaño de la Partícula , Propiedades de Superficie , Compuestos de Estaño/síntesis química , Compuestos de Estaño/químicaRESUMEN
Frankliniella occidentalis (Pergande) is an important horticultural pest that causes serious damage to rose plants, which is one of its preferred foods. In this study, rose petals, rose flowers, and 10% honey solution + kidney bean pods were chosen as foods to assess their influence on the growth, development and fecundity of F. occidentalis. The results showed that developmental time of immature F. occidentalis with the following trend: rose flowers <10% honey solution + kidney bean pods < rose petals < kidney bean pods. The longevities of both female and male adults were lowest when feeding on the rose petals and were highest when feeding on rose flowers. The fecundity was in the following order: rose flowers >10% honey solution + kidney bean pods > rose petals > kidney bean pods. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) of F. occidentalis feeding on rose petals and kidney bean pods were lower than those feeding on rose flowers and 10% honey solution + kidney bean pods. The development, longevity, fecundity, and parameters have significantly changed since F1 generation after feeding with the three food types. The results indicated that different parts of rose flowers had a significant effect on the development of thrips, and nectar and pollen had a positive effect on thrips population increase and reproduction.
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The development and reproduction of the fall armyworm (FAW), Spodoptera frugiperda, which were reared on artificial diets containing nano-graphene oxide (GO), were determined based on age-stage, two-sex life table analysis. The results showed that GO had adverse effects on FAWs. Compared with the control, the duration of the egg stage and first, second, and sixth instar larval stages increased with increasing GO concentrations; however, the lifespan of male and female adults decreased with increasing GO concentrations. Weights of FAW pupae that were supplied with GO-amended diets increased by 0.17-15.20% compared to the control. Intrinsic growth, limited growth, and net reproductive rates of FAWs feeding on GO supplemented diets were significantly lower than the control, while mean generational periods (0.5 mg/g: 38.47; 1 mg/g: 40.38; 2 mg/g: 38.42) were significantly longer than the control. The expression of genes encoding vitellogenin (Vg) and vitellogenin receptor (VgR) expression was abnormal in female FAW adults feeding on GO-amended diets; the number of eggs laid decreased relative to the control, but Vg expression increased. In conclusion, GO prolonged the developmental period of FAWs, decreased fecundity, and led to a decline in the population size. The study provides a basis for the rational use of GO as a pesticide synergist for FAW control.
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The western flower thrip (WFT) Frankliniella occidentalis (Pergande) is a serious agricultural pest with a wide host range which has developed resistance to several groups of insecticides. In this study, the effect of insecticide resistance on WFT host adaptability was explored by examining changes in detoxification enzyme activities and thrip development, and reproduction on preferred and less preferred host plants, eggplant Solanum melongena L. and broad bean Vicia faba L., respectively. Thrips were screened with spinetoram on kidney bean for six generations. Activities of glutathione S-transferase (GST), mixed function oxidases (MFOs), and cytochrome P450 enzyme (P450) in a resistant strain (RS) reared on broad bean were significantly higher than those in a sensitive strain (SS), and only carboxylesterase (CarE) increased in the RS when reared on eggplant, compared with the SS. Activities of the four detoxification enzymes in the RS reared on broad bean were significantly higher than in those reared-on eggplant. On broad bean, RS adult longevity was lower and developmental duration of offspring was shorter than those of the SS, but fecundity increased. On eggplant, RS fecundity was lower and developmental duration of offspring was shorter than those of the SS. In addition, fecundity was higher and developmental duration was longer in the RS reared on broad bean than in those reared-on eggplant. The results indicated that spinetoram resistance could change WFT host preference and that those changes might be associated with detoxification enzyme activities. Thus, it was hypothesized that adaptability of the RS to the less preferred host broad bean increased, whereas adaptability to the preferred host eggplant decreased.
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Insecticidas , Thysanoptera , Animales , Resistencia a los Insecticidas , Insecticidas/farmacología , Tablas de Vida , MacrólidosRESUMEN
Western flower thrips (Frankliniella occidentalis) pose a serious threat to the global vegetable and flower crop production. The regulatory mechanism for superoxide dismutase (SOD) in the feeding adaptation of F. occidentalis after host shifting remains unclear. In this study, the copper chaperone for SOD (CCS) and manganese SOD (MnSOD) genes in F. occidentalis were cloned, and their expression levels at different developmental stages was determined. The mRNA expression of FoCCS1 and FoMnSOD2 in F. occidentalis second-instar larvae and adult females of F1, F2, and F3 generations was analyzed after shifting the thrips to kidney bean and broad bean plants, respectively. The F2 and F3 second-instar larvae and F2 adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to kidney bean plants. The F1 second-instar larvae and F2 adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to broad bean plants. The RNA interference significantly downregulated the FoCCS1 mRNA expression levels and adult females showed significantly inhibited SOD activity after shifting to kidney bean and broad bean plants. F. occidentalis adult females subjected to RNA interference and released on kidney bean and broad bean leaves for rearing, respectively, significantly reduced the survival rate and fecundity. These findings suggest that FoCCS1 plays an active role in regulating the feeding adaptation ability of F. occidentalis after host shifting.
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Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a serious invasive pest in China. In this study, we determined whether exogenous jasmonic acid (JA) and ethylene (ET) treatments could induce resistance against F. occidentalis in faba bean plants. First, we investigated the effects of different concentrations of JA or ET alone on F. occidentalis and then assessed the effects of optimal concentrations of JA and ET combined. Our results showed that the optimal concertation of JA was 2 mmol/L and ET was 0.5 mmol/L. JA + ET mixture showed the greatest inhibitory effect in terms of oviposition and feeding. JA with ET was found to induce changes in the activities of lipoxygenase (LOX), allene oxide synthase (AOS), polyphenol oxidase (PPO), 1-aminocyclopropane 1-carboxylic acid synthase (ACS), and trypsin inhibitor (TI). This treatment also activated or inhibited the relative expression levels of LOX1, ACO2, ACS2, and AP2/ERF. Treatment of faba bean plants with JA and ET significantly prolonged F. occidentalis development and adult preoviposition period, significantly reduced per-female oviposition, and altered male longevity and offspring demographic parameters. These results indicate that JA with ET can induce defenses against the growth and development of F. occidentalis in faba bean plants.
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The western flower thrips, Frankliniella occidentalis, is a major invasive pest of commercially important crops worldwide. We compared the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and the expressions of two putative SOD and two putative POD sequences in second instar larvae and adults after three generations of adaptation to kidney bean and broad bean plants. The results showed that the SOD, POD, and CAT activities in adults were significantly higher than those in the second instar larvae. The SOD activities were significantly higher in both the second instar larvae and the adults fed on kidney bean (Phaseolus vulgaris) plants versus broad bean (Vicia faba) plants, whereas the POD and CAT activities showed the opposite trend. The gene expression data showed that the FoPOD-2 expression levels were lower in the second instar larvae after three generations of feeding on broad bean plants versus kidney bean plants. The expression levels of FoSOD-1 and FoSOD-2, and FoPOD-1 under broad bean plant treatment were higher than those under kidney bean plant treatment. Additionally, gene expression fluctuated among the different generations. Our results indicated that western flower thrips demonstrated plasticity in gene expression and activity of protective enzymes, which is related to their adaptability to the host plants. Western flower thrips can change the expression of protective enzyme genes and enzyme activity in vivo to better adapt to kidney bean and broad bean plants.
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Phaseolus , Thysanoptera , Animales , Productos Agrícolas , Flores , Larva , Phaseolus/genéticaRESUMEN
Solving the polysulfide shuttle problem is one of the core challenges for the industrialization of lithium-sulfur batteries. In this work, a triphasic composite of LDH/sulfur/rGO (LDH: layered double hydroxide, rGO: reduced graphene oxide) with a crepe cake like structure is designed and fabricated as a positive electrode material for lithium-sulfur batteries. Sulfur nanoparticles are embedded in the interlayer space of the composite and thus are well protected physically via three-dimensional wrapping and chemically via strong interaction of LDH nanoflakes with lithium polysulfides, such as ionic bonds and S···H hydrogen bonds. In addition, the flexible lamellar structure of the composite with soft graphene layers can tolerate the volume expansion of sulfur during lithiation as well as facilitate ionic permeability and electron transport, which is favorable for the redox reactions of polysulfide. The present work sheds light on the future development and industrialization of lithium-sulfur batteries.
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Exceptionally long C60 nanowires, with a length to width aspect ratio as large as 3000, are grown from a 1,2,4-trimethylbenzene solution of C60. They have been formed to possess a highly unusual morphology, with each nanowire being composed of two nanobelts joined along the growth direction to give a V-shaped cross section. The crystal structure of these nanowires is found to be orthorhombic, with the unit cell dimensions of a = 10.2 A, b = 20.5 A, and c = 25.6 A. Structural and compositional analyses enable us to explain the observed geometry with an anisotropic molecular packing mechanism that has not been observed previously in C60 crystal studies. The nanowires have been observed to be able to transform into carbon nanofibers following high-temperature treatment, but the original V-shaped morphology can be kept unchanged in the transition. A model for the nanowire morphology based upon the solvent-C60 interactions and preferential growth directions is proposed, and potentially it could be extended for use to grow different types of fullerene nanowires.
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Porous carbon materials have attracted considerable attention for their various applications such as catalyst supports for fuel cells. However, few studies focus on the effect of carbon pore structure on different alcohols electrooxidation. In this work, platinum@nitrogen-doped carbon nanospheres with tailored mesopores (Pt@NMCs) are fabricated and exhibit outstanding electrocatalytic activity and durability for alcohol oxidation because of the structural advantages such as adjustable mesopores, N-doped carbon, and embedded catalysts. More importantly, the pore size of NMCs (or called the size of the windows connecting the neighboring spherical cavities), which can be tuned simply by adjusting the diameter of colloidal silica nanospheres, has a great effect on the electrocatalytic activity and selectivity of Pt catalysts toward oxidation of alcohols (methanol, ethanol, and n-propanol). Accordingly, we can adopt optimal Pt@NMCs with appropriate pore size based on different requirements and applications.
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A new species of entomopathogenic fungi, Lecanicilliumcauligalbarum, was discovered from a survey of invertebrate-associated fungi in the Yao Ren National Forest Mountain Park in China. The synnemata of this species emerged from the corpse of a stemborer (Lepidoptera), which was hidden amongst pieces of wood on the forest floor. It differs from morphologically similar Lecanicillium species mainly in its short conidiogenous cells and ellipsoid to ovoid and aseptate conidia. Phylogenetic analysis of a combined data set comprising ITS, SSU, LSU, TEF, RPB1 and RPB2 sequence data supported the inclusion of L.cauligalbarum in the Lecanicillium genus and its recognition as a distinct species.
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Mesoporous single-crystal Co(3)O(4) was obtained using cage-containing mesoporous silicas, FDU-12 and SBA-16, as templates and characterised by XRD, HRTEM and nitrogen adsorption-desorption while SQUID magnetometry was used to probe the magnetic character.
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Hierarchically structured composites (TUD-C) with ZSM-5 crystals embedded in a well-connected mesoporous matrix were synthesized by using only one organic templating/scaffolding molecule (TPAOH).