3,014 research outputs found
Biochar-amended potting medium reduces the susceptibility of rice to root-knot nematode infections
Background: Biochar is a solid coproduct of biomass pyrolysis, and soil amended with biochar has been shown to enhance the productivity of various crops and induce systemic plant resistance to fungal pathogens. The aim of this study was to explore the ability of wood biochar to induce resistance to the root-knot nematode (RKN) Meloidogyne graminicola in rice (Oryza sativa cv. Nipponbare) and examine its histochemical and molecular impact on plant defense mechanisms.
Results: A 1.2 % concentration of biochar added to the potting medium of rice was found to be the most effective at reducing nematode development in rice roots, whereas direct toxic effects of biochar exudates on nematode viability, infectivity or development were not observed. The increased plant resistance was associated with biochar-primed H2O2 accumulation as well as with the transcriptional enhancement of genes involved in the ethylene (ET) signaling pathway. The increased susceptibility of the Ein2b-RNAi line, which is deficient in ET signaling, further confirmed that biochar-induced priming acts at least partly through ET signaling.
Conclusion: These results suggest that biochar amendments protect rice plants challenged by nematodes. This priming effect partially depends on the ET signaling pathway and enhanced H2O2 accumulation
Efeitos citotóxicos de anestesia local com lidocaína/ropivacaína em linhagens celulares de melanoma humano
ResumoJustificativaOs anestésicos locais (ALs) são geralmente considerados como seguros, mas citotoxicidade foi relatada em vários anestésicos locais usados em seres humanos, a qual não é bem investigada. No presente estudo, a citotoxicidade de lidocaína e ropivacaína e da combinação de lidocaína e ropivacaína foi avaliada em linhagens celulares de melanoma humano. Melfalano, um agente alquilante de mostarda nitrogenada, foi usado como um agente de controle para a comparação da atividade citotóxica.MétodosLinhagens celulares de melanoma, A375 e Hs294T foram expostas por uma hora a concentrações diferentes dos agentes mencionados acima. A viabilidade celular após a exposição foi determinada por citometria de fluxo.ResultadosOs ALs investigados mostraram citotoxicidade prejudicial nas linhagens celulares de melanoma estudadas dependente do tempo (p<0,001), da concentração (p<0,001) e do agente. Em ambas as linhagens de células A375 e Hs294T, níveis mínimos de viabilidade celular foram encontrados após 72 horas de exposição a esses agentes. Lidocaína a 2% provocou uma redução das células vitais para 10%±2% e 14%±2% em A375 e Hs294T, respectivamente, após 72 horas de exposição. Ropivacaína a 0,75% após 72 horas reduziu as células viáveis para 15%±3% e 25%±3%, em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas para a combinação foi de 10%±2% e 18%±2% em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas ao melfalano foi de 8%±1% e 12±2, em A375 e Hs294T, respectivamente.ConclusãoOs ALs têm atividade citotóxica em linhagens de celulares de melanoma humano de modo dependente do tempo, da concentração e do agente. A apoptose nas linhagens celulares foi mediada por meio da atividade das caspases‐3 e caspases‐8.AbstractBackgroundLocal anesthetics (LAs) are generally considered as safe, but cytotoxicity has been reported for several local anesthetics used in humans, which is not well investigated. In the present study, the cytotoxicity of lidocaine, ropivacaine and the combination of lidocaine and ropivacaine were evaluated on human melanoma cell lines. Melphalan, a nitrogen mustard alkylating agent, was used as a control agent for comparison of cytotoxic activity.MethodsMelanoma cell lines, A375 and Hs294T, were exposed to 1h to different concentrations of above agents. Cell‐viability after exposure was determined by flow cytometry.ResultsInvestigated LAs showed detrimental cytotoxicity on studied melanoma cell lines in time‐ (p<0.001), concentration‐ (p<0.001), and agent dependant. In both A375 and Hs294T cell lines, minimum cell viability rates were found after 72h of exposure to these agents. Lidocaine 2% caused a reduction of vital cells to 10%±2% and 14%±2% in A375 and Hs294T, respectively after 72h of exposure. Ropivacaine 0.75% after 72h reduced viable cells to 15%±3% and 25%±3% in A375 and Hs294T, respectively. Minimum cell viability after 72h exposure to the combination was 10%±2% and 18%±2% in A375 and Hs294T, respectively. Minimum cell viability after 72h exposure to melphalan was 8%±1% and 12%±2%, in A375 and Hs294T, respectively.ConclusionLAs have cytotoxic activity on human melanoma cell lines in a time‐, concentration‐ and agent‐dependant manner. Apoptosis in the cell lines was mediated through activity of caspases‐3 and caspases‐8
A Semisupervised Feature Selection with Support Vector Machine
Feature selection has proved to be a beneficial tool in learning problems with the main advantages of interpretation and generalization. Most existing feature selection methods do not achieve optimal classification performance, since they neglect the correlations among highly correlated features which all contribute to classification. In this paper, a novel semisupervised feature selection algorithm based on support vector machine (SVM) is proposed, termed SENFS. In order to solve SENFS, an efficient algorithm based on the alternating direction method of multipliers is then developed. One advantage of SENFS is that it encourages highly correlated features to be selected or removed together. Experimental results demonstrate the effectiveness of our feature selection method on simulation data and benchmark data sets
Modeling in SolidWorks and analysis of temperature and thermal stress during construction of intake tower
AbstractWith a focus on the intake tower of the Yanshan Reservoir, this paper discusses the method of modeling in the 3D CAD software SolidWorks and the interface processing between SolidWorks and the ANSYS code, which decreases the difficulty in modeling complicated models in ANSYS. In view of the function of the birth-death element and secondary development with APDL (ANSYS parametric design language), a simulation analysis of the temperature field and thermal stress during the construction period of the intake tower was conveniently conducted. The results show that the temperature rise is about 29.934 °C over 3 or 4 days. The temperature differences between any two points are less than 24 °C. The thermal stress increases with the temperature difference and reaches its maximum of 1.68 MPa at the interface between two concrete layers
Determination of Anthraquinone Content in Lac Dye Through Combined Spectrophotometry and HPCE
AbstractThis study is aim to establish the method for determination of anthraquinone content in lac dye with the combined spectrophotometry and HPCE, With the 0.5%Mg(Ac)2-CH3OH solution as the colour-developing agent, the carminic acid concentration within the concentration of 5∼50μg/mL presents a good linear relationship with the absorbance under the wavelength of 540nm (R=0.9994). Through the test, the results showed that the total anthraquinone content in lac dye was 82.13%, average recovery rate 97.80%, RSD 1.31%. Under 291nm detection wavelength and 25°C column temperature, with pH8.035 60mmol/LNa2HPO4-Na2B4O7 • 10H2O mixed buffer as background electrolyte and 60cm × 75μm uncoated capillary column as separation lanes, separation voltage 20kV, pressure 0.5psi × 10s for sample injection, the relative contents of five components laccaic acids A, B, C, D, E were measured by peak area normalization method; combined with the spectrophotometry, the contents of five anthraquinone components - laccaic acids A, B, C, D, E were determined, respectively 40.42%, 17.66%, 2.54%, 1.51%, 20.00%
Global Optimization of Minority Game by Smart Agents
We propose a new model of minority game with so-called smart agents such that
the standard deviation and the total loss in this model reach the theoretical
minimum values in the limit of long time. The smart agents use trail and error
method to make a choice but bring global optimization to the system, which
suggests that the economic systems may have the ability to self-organize into a
highly optimized state by agents who are forced to make decisions based on
inductive thinking for their limited knowledge and capabilities. When other
kinds of agents are also present, the experimental results and analyses show
that the smart agent can gain profits from producers and are much more
competent than the noise traders and conventional agents in original minority
game.Comment: 5 pages, 5 figure
Interface-tuning of ferroelectricity and quadruple-well state in CuInPS via ferroelectric oxide
Ferroelectric van der Waals CuInPS possesses intriguing
quadruple-well states and negative piezoelectricity. Its technological
implementation has been impeded by the relatively low Curie temperature (bulk
~42 {\deg}C) and the lack of precise domain control. Here we show that
CuInPS can be immune to the finite size effect and exhibits enhanced
ferroelectricity, piezoelectricity, and polar alignment in the ultrathin limit
when interfaced with ferroelectric oxide PbZrTiO films.
Piezoresponse force microscopy studies reveal that the polar domains in thin
CuInPS fully conform to those of underlying
PbZrTiO, where the piezoelectric coefficient changes sign
and increases sharply with reducing thickness. High temperature
domain imaging points to a significantly enhanced exceeding 200 {\deg}C
for 13 nm CuInPS on PbZrTiO. Density functional
theory modeling and Monte Carlo simulations show that the enhanced polar
alignment and can be attributed to interface-mediated structure
distortion in CuInPS. Our study provides an effective material strategy
to engineer the polar properties of CuInPS for flexible nanoelectronic,
optoelectronic, and mechanical applications.Comment: 21 pages, 5 figures, and Supporting Informatio
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