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1.
Carbohydr Polym ; 320: 121251, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37659828

RESUMO

Currently, the quest for more renewable and biodegradable materials is a scientific priority to address the problems of petroleum-based plastics are difficult to degrade. In this work, cellulose nanocrystals (CNC) have been used as a template and four morphologies of CNC-ZnO nanocomposites were prepared via a hydrothermal method, and CNC-ZnO/polylactic acid (PLA) composite films were obtained by solution casting. We find that CNC-ZnO nanocomposites as heterogeneous nucleating agents improved the crystallinity and the film with flower-like CNC-ZnO was improved by 2.4 %. Ea required for thermal degradation of the PLA films decreased to 66-81 % of that of neat PLA, calculated by the Kissinger method, the Friedman method, and the Flynn-Wall-Ozawa (FWO) method. The R2 model was the solid degradation mechanism of the PLA films, analyzed through the Coats-Redfern method and the Criado method. The H-bond content of the composite films was significantly reduced after thermal aging at 150 °C. We found that three-dimensional CNC-ZnO (ZnO-3) made more prominent contributions to the crystallization, thermal degradation, and thermal aging of PLA films than other dimensional. The thermal properties can be regulated by the dimension, size, and apparent morphology of CNC-ZnO nanoparticles.

2.
Biology (Basel) ; 12(7)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37508331

RESUMO

Cotton Verticillium wilt, mainly caused by Verticillium dahliae, has a serious impact on the yield and quality of cotton fiber. Many microRNAs (miRNAs) have been identified to participate in plant resistance to V. dahliae infection, but the exploration of miRNA's function mechanism in plant defense is needed. Here, we demonstrate that the ghr-miR482b-GhRSG2 module mediates cotton plant resistance to V. dahliae infection. Based on the mRNA degradation data and GUS fusion experiments, ghr-miR482b directedly bonds to GhRSG2 mRNA to lead to its degradation. The knockdown and overexpression of ghr-miR482b through virus-induced gene silencing strategies enhanced (decreased by 0.39-fold in disease index compared with the control) and weakened (increased by 0.46-fold) the plant resistance to V. dahliae, respectively. In addition, silencing GhRSG2 significantly increased (increased by 0.93-fold in disease index) the plant sensitivity to V. dahliae compared with the control plants treated with empty vector. The expression levels of two SA-related disease genes, GhPR1 and GhPR2, significantly decreased in GhRSG2-silenced plants by 0.71 and 0.67 times, respectively, and in ghr-miR482b-overexpressed (OX) plants by 0.59 and 0.75 times, respectively, compared with the control, whereas the expression levels of GhPR1 and GhPR2 were significantly increased by 1.21 and 2.59 times, respectively, in ghr-miR482b knockdown (KD) plants. In sum, the ghr-miR482b-GhRSG2 module participates in the regulation of plant defense against V. dahliae by inducing the expression of PR1 and PR2 genes.

3.
Plant Sci ; 330: 111647, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36806608

RESUMO

Many cotton miRNAs in root responding to Verticillium dahliae infection have been identified. Conversely, the miRNAs in leaf distantly responding to this fungal infection from roots via systemic acquired resistance (SAR) remain to be explored. Here, we constructed two groups of leaf sRNA libraries in cotton treated with V. dahliae via root-dipped method at 7- and 10-day post inoculation. Analysis of high-throughput sRNA sequencing identified 75 known and 379 novel miRNAs, of which 41 miRNAs significantly differentially expressed in fungal treatment plant leaves compared to the mock treatment at two time points. Then we characterized the cotton miR530-SAP6 module as a representative in the distant response to V. dahliae infection in roots. Based on degradome data and a luciferase (LUC) fusion reporter analysis, ghr-miR530 directedly cleaved GhSAP6 mRNA during the post-transcriptional process. Silencing of ghr-miR530 increased plant defense to this fungus, while its overexpression attenuated plant resistance. In link with ghr-miR530 function, the knockdown of GhSAP6 also decreased the plant resistance, resulting from down-regulation of SA-relative gene expression including GhNPR1 and GhPR1. In all, these results demonstrated that there are numerous miRNAs in leaf distantly responding to V. dahliae infection in roots mediate plant immunity.


Assuntos
Ascomicetos , MicroRNAs , Pequeno RNA não Traduzido , Verticillium , Resistência à Doença/genética , Verticillium/fisiologia , Ascomicetos/genética , MicroRNAs/genética , Gossypium/genética , Gossypium/metabolismo , Doenças das Plantas/microbiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
4.
Appl Opt ; 60(23): 6761-6768, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34613154

RESUMO

Optical coherence tomography (OCT) technology can obtain a clear retinal structure map, which is greatly beneficial for the diagnosis of retinopathy. Ophthalmologists can use OCT technology to analyze information about the retina's internal structure and changes in retinal thickness. Therefore, segmentation of retinal layers in images and screening for retinal diseases have become important goals in OCT scanning. In this paper, we propose the multiscale dual attention (MSDA)-UNet network, an MSDA mechanism network for OCT lesion area segmentation. The MSDA-UNet network introduces position and multiscale channel attention modules to calculate a global reference for each pixel prediction. The network can extract the lesion area information of OCT images of different scales and perform end-to-end segmentation of the OCT retinopathy area. The network framework was trained and tested on the same OCT dataset and compared with other OCT fluid segmentation methods to assess its effectiveness.


Assuntos
Retina/diagnóstico por imagem , Doenças Retinianas/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Conjuntos de Dados como Assunto , Aprendizado Profundo , Humanos , Redes Neurais de Computação
5.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 12): m1527, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23468736

RESUMO

In the title Cu(I) compound, [Cu(C6H5N5)(C18H15P)2]BF4, the Cu(I) cation is N,N'-chelated by a 5-(pyridin-2-yl)-1H-tetra-zole ligand and coordinated by two triphenyl-phosphane ligands in a distorted tetra-hedral geometry. The tetra-zole and pyridine rings are essentially coplanar [dihedral angle = 4.1 (3)°]. The tetra-fluoridoborate anion links to the complex cation via an N-H⋯F hydrogen bond.

6.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 11): m1394, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23284366

RESUMO

In the title compound, [Co(C(6)H(3)ClNO(2))(2)(H(2)O)(4)]·4H(2)O, the Co(II) cation is located on an inversion center and is coordinated by four water mol-ecules and two 6-chloro-pyridine-3-carboxyl-ate anions in a slightly distorted octa-hedral geometry. In the crystal, complex mol-ecules and lattice water mol-ecules are linked by O-H⋯O and O-H⋯N hydrogen bonds into a three-dimensional network.

7.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 1): m88-9, 2010 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-21522603

RESUMO

In the title rhenium(I) complex, [ReBr(C(13)H(9)N(3)O)(CO)(3)]·CH(2)Cl(2), the dichloro-methane solvent mol-ecule is disordered over two positions with an occupancy ratio of 0.81 (15):0.19 (15). The Re(I) atom is coordinated by two N atoms from a 2-phenyl-5-(pyridin-2-yl-κN)-1,3,4-oxadiazole (L) ligand, three C atoms from three carbonyl groups and a Br atom in a distorted octa-hedral geometry. The three rings in L are almost coplanar (a mean plane fitted through all non-H atoms of this ligand has an r.m.s. deviation of 0.063 Å), and the carbonyl ligands are coordinated in a fac arrangement.

8.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 1): m9-m10, 2010 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-21522604

RESUMO

In the title compound, [ReBr(C(14)H(11)N(3)O)(CO)(3)]·CH(2)Cl(2), the coordination geometry of the Re(I) atom is a distorted ReC(3)N(2)Br octa-hedron with the carbonyl C atoms in a fac arrangement. Within the 2-(pyridin-2-yl)-5-p-tolyl-1,3,4-oxadiazole ligand, the dihedral angles between the oxadiazole ring and the pyridine (py) and benzene (bz) rings are 1.7 (2) and 7.1 (2)°, respectively, and the dihedral angle between the py and bz rings is 5.5 (2)°. In the crystal, aromatic π-π stacking between the oxadiazole rings of adjacent mol-ecules [centroid-centroid separation = 3.465 (3) Å] is seen.

9.
Chem Commun (Camb) ; (39): 5868-70, 2009 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19787124

RESUMO

The first optical oxygen sensor based on Cu(I) complex-polystyrene composite nanofibrous membranes, showing high sensitivity (I(0)/I(100) = 15.56), good linear Stern-Volmer characteristics (R(2) = 0.9966) and short response/recovery time (t(decrease) (s) = 7 and t(increase) (s) = 14), has been prepared; these results represent the best values reported for oxygen sensors based on Cu(I) complexes.


Assuntos
Cobre/química , Nanoestruturas/química , Oxigênio/química , Poliestirenos/química , Técnicas Biossensoriais , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência
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