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1.
J Colloid Interface Sci ; 625: 978-989, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35779524

RESUMO

As one of the most promising candidates for sodium-ion battery anodes, hard carbons suffer from inferior rate performance owing to limited ion transfer rate and sluggish electrochemical kinetics. In this work, novel carbon nanosheets (CNS) with hexagonal ordered conical macropores are prepared. The CNS has a very thin thickness of approximately 370 nm, and the conical pores are penetrated through the whole nanosheet, forming well-connected ion transport freeway. In addition, the carbon microcrystal structure and interlayer spacing can be well tailored by adjusting the carbonization temperature, thereby controlling the sodium storage behavior of carbon electrodes. These structural merits endow CNS with accelerated ion transfer, minimized ion diffusion distance and fast electrochemical kinetics. Consequently, the CNS presents superior electrochemical performance. It delivers a high reversible capacity of 298 mAh g-1 at 0.1 A g-1; and after repeated charge/discharge for 500 times at 1 A g-1, its capacity remains 195 mA h g-1, with no rapid capacity loss. More importantly, CNS exhibits outstanding rate capability. Even under a very high current density of 2 A g-1, it still displays a large capacity of 210 mAh g-1, higher than most of state-of-the-art carbon anodes.

2.
Phytopathology ; 111(4): 659-670, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33635092

RESUMO

Grape white rot (Coniothyrium diplodiella) is a major fungal disease affecting grape yield and quality. Quantitative trait locus (QTL) analysis is an important method for studying important horticultural traits of grapevine. This study was conducted to construct a high-density map and conduct QTL mapping for grapevine white rot resistance. A mapping population with 177 genotypes was developed from interspecific hybridization of a white rot-resistant cultivar (Vitis vinifera × V. labrusca 'Zhuosexiang') and white rot-susceptible cultivar (V. vinifera 'Victoria'). Single-nucleotide polymorphism (SNP) markers were developed by restriction site-associated DNA sequencing. The female, male, and integrated maps contained 2,501, 4,110, and 6,249 SNP markers with average genetic distances of adjacent markers of 1.25, 0.77, and 0.50 cM, respectively. QTL mapping was conducted based on white rot resistance identification of 177 individuals in July and August of 2017 and 2018. Notably, one stable QTL related to white rot resistance was detected and located on linkage group LG14. The phenotypic variance ranged from 12.93 to 13.43%. An SNP marker (chr14_3929380), which cosegregated with white rot resistance, was discovered and shows potential for use in marker-assisted selection to generate new grapevine cultivars with resistance to white rot.


Assuntos
Locos de Características Quantitativas , Vitis , Ascomicetos , Feminino , Ligação Genética , Masculino , Fenótipo , Doenças das Plantas/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Análise de Sequência de DNA , Vitis/genética
3.
Proc Natl Acad Sci U S A ; 116(29): 14682-14687, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31262812

RESUMO

Not all encounters with pathogens are stochastic and insects can adjust their immune management in relation to cues associated with the likelihood of infection within a life cycle as well as across generations. In this study we show that female insects (bed bugs) up-regulate immune function in their copulatory organ in anticipation of mating by using feeding cues. Male bed bugs only mate with recently fed females and do so by traumatic insemination (TI). Consequently, there is a tight temporal correlation between female feeding and the likelihood of her being infected via TI. Females that received predictable access to food (and therefore predictable insemination and infection cycles) up-regulated induced immunity (generic antibacterial activity) in anticipation of feeding and mating. Females that received unpredictable (but the same mean periodicity) access to food did not. Females that anticipated mating-associated immune insult received measurable fitness benefits (survival and lifetime reproductive success) despite laying eggs at the same rate as females that were not able to predict these cycles. Given that mating is a time of increased likelihood of infection in many organisms, and is often associated with temporal cues such as courtship and/or feeding, we propose that anticipation of mating-associated infection in females may be more widespread than is currently evidenced.


Assuntos
Percevejos-de-Cama/fisiologia , Comportamento Alimentar/fisiologia , Imunidade/fisiologia , Inseminação/imunologia , Preferência de Acasalamento Animal/fisiologia , Animais , Percevejos-de-Cama/microbiologia , Sinais (Psicologia) , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Masculino , Fatores Sexuais
4.
Small ; 13(38)2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28783256

RESUMO

A novel metallo-organic molecule, ferrocene, is selected as building block to construct Fe3 O4 dots embedded in 3D honeycomb-like carbon (Fe3 O4 dots/3DHC) by using SiO2 nanospheres as template. Unlike previously used inorganic Fe3 O4 sources, ferrocene simultaneously contains organic cyclopentadienyl groups and inorganic Fe atoms, which can be converted to carbon and Fe3 O4 , respectively. Atomic-scale Fe distribution in started building block leads to the formation of ultrasmall Fe3 O4 dots (≈3 nm). In addition, by well controlling the feed amount of ferrocene, Fe3 O4 dots/3DHC with well-defined honeycomb-like meso/macropore structure and ultrathin carbon wall can be obtained. Owing to unique structural features, Fe3 O4 dots/3DHC presents impressive lithium storage performance. The initial discharge and reversible capacities can reach 2047 and 1280 mAh g-1 at 0.05 A g-1 . With increasing the current density to 1 and 3 A g-1 , remarkable capacities of 963 and 731 mAh g-1 remain. Moreover, Fe3 O4 dots/3DHC also has superior cycling stability, after a long-term charge/discharge for 200 times, a high capacity of 1082 mAh g-1 can be maintained (80% against the capacity of the 2nd cycle).

5.
ACS Appl Mater Interfaces ; 9(18): 15557-15565, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28406286

RESUMO

A covalent bond-induced surface-confined cross-linking is reported to construct one-dimensional coaxial CNT@microporous carbon composite (CNT@micro-C). Octaphenyl polyhedral oligomeric silsesquioxane (Ph-POSS) composed of eight phenyls and a -Si8O12 cage was selected as precursor for microporous carbon. The layer-by-layer cross-linking of phenyl anchored Ph-POSS on the surface of CNT; after carbonization and etching of -Si8O12 cages, CNT@micro-C including CNT core and microporous carbon shell was harvested. The thickness of microporous carbon shell can be well tailored from 6.0 to 20.0 nm, and the surface area of CNT@micro-C can reach 1306 m2 g-1. CNT@micro-C combines the structural advantages of CNT and microporous carbon, presenting large surface area, high electrical conductivity, fast ion transfer speed, and short ion transfer distance. When used as electrode material, CNT@micro-C reveals superior supercapacitive performance; for example, its capacitance can reach 243 F g-1 at 0.5 A g-1 and slightly decreases to 209 F g-1 at 10 A g-1, indicating a capacitance retention of 86%. Even at a very high scan rate of 50 A g-1, a high capacitance of 177 F g-1 is retained, giving a capacitance retention of 73%.

6.
J Anim Ecol ; 85(1): 178-86, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26332860

RESUMO

Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature preference can facilitate shifts in strategy, but not without inevitable trade-offs.


Assuntos
Drosophila melanogaster/microbiologia , Drosophila melanogaster/fisiologia , Metarhizium/fisiologia , Animais , Comportamento Apetitivo , Temperatura Baixa , Feminino , Longevidade , Reprodução
7.
Evolution ; 68(8): 2225-33, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24862588

RESUMO

Many have argued that we may be able to extend life and improve human health through hormesis, the beneficial effects of low-level toxins and other stressors. But, studies of hormesis in model systems have not yet established whether stress-induced benefits are cost free, artifacts of inbreeding, or come with deleterious side effects. Here, we provide evidence that hormesis results in trade-offs with immunity. We find that a single topical dose of dead spores of the entomopathogenic fungus, Metarhizium robertsii, increases the longevity of the fruit fly, Drosophila melanogaster, without significant decreases in fecundity. We find that hormetic benefits of pathogen challenge are greater in lines that lack key components of antifungal immunity (Dif and Turandot M). And, in outbred fly lines, we find that topical pathogen challenge enhances both survival and fecundity, but reduces ability to fight off live infections. The results provide evidence that hormesis is manifested by stress-induced trade-offs with immunity, not cost-free benefits or artifacts of inbreeding. Our findings illuminate mechanisms underlying pathogen-induced life-history trade-offs, and indicate that reduced immune function may be an ironic side effect of the "elixirs of life."


Assuntos
Drosophila melanogaster/imunologia , Hormese , Longevidade , Animais , Resistência à Doença , Drosophila melanogaster/genética , Drosophila melanogaster/microbiologia , Feminino , Fertilidade , Técnicas de Inativação de Genes , Genótipo , Temperatura Alta , Masculino , Metarhizium/patogenicidade , Estresse Fisiológico
8.
Proc Biol Sci ; 280(1773): 20132018, 2013 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-24174107

RESUMO

Although it is well known that mating increases the risk of infection, we do not know how females mitigate the fitness costs of sexually transmitted infections (STIs). It has recently been shown that female fruitflies, Drosophila melanogaster, specifically upregulate two members of the Turandot family of immune and stress response genes, Turandot M and Turandot C (TotM and TotC), when they hear male courtship song. Here, we use the Gal4/UAS RNAi gene knockdown system to test whether the expression of these genes provides fitness benefits for females infected with the entomopathogenic fungus, Metarhizium robertsii under sexual transmission. As a control, we also examined the immunity conferred by Dorsal-related immunity factor (Dif), a central component of the Toll signalling pathway thought to provide immunity against fungal infections. We show that TotM, but not TotC or Dif, provides survival benefits to females following STIs, but not after direct topical infections. We also show that though the expression of TotM provides fecundity benefits for healthy females, it comes at a cost to their survival, which helps to explain why TotM is not constitutively expressed. Together, these results show that the anticipatory expression of TotM promotes specific immunity against fungal STIs and suggest that immune anticipation is more common than currently appreciated.


Assuntos
Proteínas de Drosophila/imunologia , Drosophila melanogaster/imunologia , Proteínas de Choque Térmico/imunologia , Comportamento Sexual Animal , Animais , Resistência à Doença , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/microbiologia , Drosophila melanogaster/fisiologia , Feminino , Fertilidade , Regulação da Expressão Gênica , Proteínas de Choque Térmico/antagonistas & inibidores , Proteínas de Choque Térmico/fisiologia , Masculino , Metarhizium/imunologia , Interferência de RNA , Transdução de Sinais
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