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1.
Mol Plant ; 17(4): 614-630, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38454602

RESUMO

The infection of host plants by many different viruses causes reactive oxygen species (ROS) accumulation and yellowing symptoms, but the mechanisms through which plant viruses counteract ROS-mediated immunity to facilitate infection and symptom development have not been fully elucidated. Most plant viruses are transmitted by insect vectors in the field, but the molecular mechanisms underlying virus‒host-insect interactions are unclear. In this study, we investigated the interactions among wheat, barley yellow dwarf virus (BYDV), and its aphid vector and found that the BYDV movement protein (MP) interacts with both wheat catalases (CATs) and the 26S proteasome ubiquitin receptor non-ATPase regulatory subunit 2 homolog (PSMD2) to facilitate the 26S proteasome-mediated degradation of CATs, promoting viral infection, disease symptom development, and aphid transmission. Overexpression of the BYDV MP gene in wheat enhanced the degradation of CATs, which leading to increased accumulation of ROS and thereby enhanced viral infection. Interestingly, transgenic wheat lines overexpressing BYDV MP showed significantly reduced proliferation of wingless aphids and an increased number of winged aphids. Consistent with this observation, silencing of CAT genes also enhanced viral accumulation and reduced the proliferation of wingless aphids but increased the occurrence of winged aphids. In contrast, transgenic wheat plants overexpressing TaCAT1 exhibited the opposite changes and showed increases in grain size and weight upon infection with BYDV. Biochemical assays demonstrated that BYDV MP interacts with PSMD2 and promotes 26S proteasome-mediated degradation of TaCAT1 likely in a ubiquitination-independent manner. Collectively, our study reveals a molecular mechanism by which a plant virus manipulates the ROS production system of host plants to facilitate viral infection and transmission, shedding new light on the sophisticated interactions among viruses, host plants, and insect vectors.


Assuntos
Afídeos , Luteovirus , Complexo de Endopeptidases do Proteassoma , Viroses , Animais , Triticum , Afídeos/genética , Catalase , Proteínas Virais , Espécies Reativas de Oxigênio , Luteovirus/genética , Plantas Geneticamente Modificadas , Doenças das Plantas
2.
Neuropsychiatr Dis Treat ; 19: 775-784, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37051416

RESUMO

Background: Hypoxia inducible factor-1α (HIF-1α) regulates glucose metabolism during ischemia. This study investigated the effect of recombinant adenovirus HIF-1ɑ on neurological function and energy metabolism in a rat cerebral ischemia-reperfusion model. Methods: Rats were divided into four groups: sham-operated (Sham) group, cerebral ischemia-reperfusion (CIR) group, recombinant adenovirus empty vector (Ad) group, and recombinant adenovirus-mediated HIF-1α (AdHIF-1α) group. The AdHIF-1α group and the Ad group were injected with AdHIF-1α and Ad in the lateral ventricle. The mNSS was performed at post-ischemia day 0 (P0) and P1, P14 and P28. At P14, the cerebral infarct volume was compared. At P28, HE staining, Nissl stains and TUNEL staining were performed. The expression of HIF-1α, GLUT1 and PFKFB3 were evaluated by Western Blot and immunohistochemistry. High performance liquid chromatography (HPLC) was used to determine the expression of GLUT1 and PFKFB3, and the level of energy metabolites: ATP, ADP and AMP. Results: mNSS scores in the AdHIF-1α group were consistently lower than those in the CIR and Ad groups from P14 (P < 0.05) and Ad groups (P < 0.05). The cerebral infarct volume was reduced in the AdHIF-1α group compared with that in CIR group and Ad group (P < 0.05). At P28, HE showed better pathological changes in AdHIF-1α group. The number of Nissl bodies was increased in the AdHIF-1α group compared with the CIR and Ad groups (P < 0.05). The number of apoptotic cells in the AdHIF-1α group was fewer than that in the CIR and Ad groups (P < 0.05). The expression of HIF-1α, GLUT1 and PFKFB3 was significantly higher in the AdHIF-1α group compared with the CIR and Ad groups (P < 0.05). The ATP, ADP and AMP in the ischemic penumbra were also higher in the AdHIF-1α group (P < 0.05). Conclusion: HIF-lα promoted neurological function recovery and decreased cerebral infarct volume in rats after cerebral ischemia-reperfusion injury by improving energy metabolism.

3.
Front Public Health ; 10: 840379, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35273942

RESUMO

The seismic resilience of water supply systems can be impacted by numerous factors, but what these factors are in the rural context of China is unknown. In this study, 41 potential influencing factors of seismic-resilience for rural water supply system (RWSS) were obtained through a literature review and semi-structured expert interview, comprising 26 general influencing factors (GFs) and 15 water supply safety influencing factors (SFs). This study verified and ranked these factors through a questionnaire survey delivered to RWSS stakeholders in Sichuan Province, China. Based on 123 valid, returned questionnaires, these factors are divided into 9 factor groups through factor analysis performed on GFs and SFs, respectively, of which "economic resilience" and "organizational resilience in disaster prevention stage" are shown to be the most important factor groups. Additionally, it found that the experience of earthquake events significantly affects the perceptions of stakeholders on the importance of certain factors. Specifically, stakeholders who have experienced an earthquake prioritize the post-earthquake resilience of the system, while those who have not experienced an earthquake prioritize the absorption capacity of the system in the disaster prevention stage. Thus, it is not appropriate to use fixed weights to evaluate the seismic resilience of RWSSs. Significantly, this outcome differs from existing findings on the resilience of Urban Water Supply Systems (UWSSs), where "technical resilience" is the key dimension. These findings can help decision-makers fully understand the factors affecting the seismic resilience of RWSSs in China, and in doing so, augment the strengthening of rural water supply.


Assuntos
Terremotos , Água , China , Análise Fatorial , Humanos , Abastecimento de Água
4.
Sci Rep ; 12(1): 4323, 2022 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-35279670

RESUMO

China suffers from frequent large-scale earthquakes, posing a significant challenge to the development and integrity of its rural water supply system (RWSS). The earthquake resilience of water supply systems is understood to be a function of multifaceted factors, which are time- and space-dependent. Measuring the seismic-resilience of RWSS in China remains a challenge. This paper proposes a multi-stage comprehensive evaluation framework, focusing on the relationship between multi-dimensional factors and the seismic- resilience of RWSS in rural areas, across three stages: before, during and after earthquake events. This study comprises four steps: (1) Development of a multi-stage evaluation conceptual framework; (2) identification of seismic-resilience factors; (3) verification of the relationships between factors and stages; and (4) formation of the final evaluation framework. The relationship between multi-dimensional factors is confirmed by a method of triangulation through the quantitative analysis of PLS-SEM combined with the qualitative literature analysis, highlighting the causal approach of the resilience of RWSSs, so as to better understand the resilience state of each stage of disaster. Understanding these factors and their influence on the seismic capacity of RWSS will enable local authorities to recognize the existing advantages and disadvantages of these factors, so as to carry out better resilience practice in all stages of disasters.


Assuntos
Desastres , Terremotos , China , Projetos de Pesquisa , Abastecimento de Água
5.
Rev Sci Instrum ; 92(10): 104501, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34717411

RESUMO

Errors in the attitude of optical payloads onboard remote-sensing satellites have a significant impact on image quality and high-precision quantification. This study presents two on-orbit calibration techniques for optical payloads. Self-calibration of the orientation of the optical axis of an optical payload can be achieved through on-orbit observation and imaging of star points based on the pinhole imaging principle. Separate on-orbit observation and imaging of star points can facilitate the mutual calibration of an optical payload and a star sensor as well as the correction of their installation errors. These two techniques are validated through ground and on-orbit satellite tests. The results show the following: The self-calibration error for a typical remote-sensing satellite is better than 0.2″ and the mutual-calibration error is better than 2″ for its optical payload and star sensor. Self-calibration and mutual calibration are effective for improving the calibration accuracy for the on-orbit orientation of optical payloads.

6.
J Microencapsul ; 37(6): 445-456, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32524873

RESUMO

Aims: The present work investigates the effect of tartary buckwheat flavonoid (TBF) capsules on the physical and chemical properties of yoghurt using polymeric whey protein (PWP) as a wall material.Methods: PWP was prepared by thermal polymerisation. TBF was encapsulated using PWP as the wall material via the pore-coagulation bath method. The physicochemical properties of the TBF capsules, such as the entrapment yield, moisture, average particle size, particle size distribution, surface morphology, molecular interactions, and thermal stability were investigated, in addition to the release of TBF in simulated gastric and intestinal juices. Yoghurt formulation was carried out using encapsulated TBF (3%, w/w), blank PWP beads (2.7%, w/w), and unencapsulated TBF (0.3%, w/w). A control yoghurt sample was prepared without these ingredients. The effects of encapsulated TBF on the chemical composition, acidity, texture, synaeresis, sensory properties, number of Streptococcus thermophilus and Lactobacillus, and other physical and chemical properties of the yoghurt were investigated.Results: TBF capsules were found to be sphere-shaped with porous surfaces, an average particle size of 1728.67 µm, an encapsulation yield of 92.85 ± 1.98% (w/w), and a glass transition temperature of 152.06 °C. When the TBF capsules were exposed to simulated gastric fluid for 4 h, the TBF release rate was 15.75% (w/w), while in simulated intestinal fluid, the TBF release rate reached 65.99% (w/w) after 1 h. After 5-6 h in simulated intestinal fluid, the TBF release rate reached 100% (w/w). The protein content of the yoghurt with encapsulated TBF was 3.57 ± 0.26% (w/w, p < 0.01), and the numbers of Lactobacillus and Streptococcus thermophilus were 2.45 ± 0.98 × 108 (p < 0.01) and 5.43 ± 2.24 × 107 CFU/mL (p < 0.05), respectively, with strong water retention being detected (p < 0.01). Samples containing the encapsulated TBF exhibited a significantly higher acceptability than the unencapsulated TBF (p < 0.01).Conclusions: Encapsulation using PWP effectively delivers TBF to the small intestine through the stomach. It also masks the bitter taste, enhances the colour of TBF-containing yoghurt, and improves the physical and chemical properties of the yoghurt.


Assuntos
Fagopyrum/química , Flavonoides/química , Proteínas do Soro do Leite/química , Iogurte , Varredura Diferencial de Calorimetria , Composição de Medicamentos , Liberação Controlada de Fármacos , Tamanho da Partícula , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier , Iogurte/análise
7.
Phytother Res ; 31(1): 140-151, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28058783

RESUMO

Larrea nitida Cav. (LNC), which belongs to the family Zygophyllaceae, is widely indigenous and used in South America to treat various pathological conditions. It contains the antioxidant and antiinflammatory but toxic nordihydroguaiaretic acid (NDGA) as well as O-methylated metabolite of NDGA (MNDGA) as bioactive compounds. The hepatic metabolism-based toxicological potential of extracts of LNC (LNE), NDGA, and MNDGA has not previously been reported. The present study aimed to characterize the phase I and phase II hepatic metabolism and reactive intermediates of LNE, NDGA, and MNDGA and their effects on the major drug-metabolizing enzymes in vitro and ex vivo. A methanol extract of LNC collected from Chile as well as NDGA and MNDGA isolated from LNE were subjected to metabolic stability assays in liver microsomes in the presence of the cofactors reduced nicotinamide dinucleotide phosphate (NADPH) and/or uridine 5'-diphosphoglucuronic acid (UDPGA). Cytochrome P450 (CYP) inhibition assays were performed using CYP isozyme-specific model substrates to examine the inhibitory activities of LNE, NDGA, and MNDGA, which were expressed as % inhibition and IC50 values. Ex vivo CYP induction potential was investigated in the liver microsomes prepared from the rats intraperitoneally administered with LNE. Glutathione (GSH) adduct formation was monitored by LC-MS3 analysis of the microsomal incubation samples with either NDGA or MNDGA and an excess of GSH to determine the formation of electrophilic reactive intermediates. Both NDGA and MNDGA were stable to NADPH-dependent phase I metabolism, but labile to glucuronide conjugation. LNE, NDGA, and MNDGA showed significant inhibitory effects on CYP1A2, 2C9, 2D6, and/or 3A4, with IC50 values in the micromolar range. LNE was found to be a CYP1A2 inducer in ex vivo rat experiments, and mono- and di-GSH adducts of both NDGA and MNDGA were identified by LC-MS3 analysis. Our study suggests that hepatic clearance is the major elimination route for the lignans NDGA and MNDGA present in LNE. These lignans may possess the ability to modify biomacromolecules via producing reactive intermediates. In addition, LNE, NDGA, and MNDGA are found to be inhibitors for various CYP isozymes such as CYP2C9 and 3A4. Thus, the consumption of LNC as an herbal preparation or NDGA may cause metabolism-driven herb-drug interactions. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Larrea/química , Lignanas/química , Fígado/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Animais , Feminino , Interações Ervas-Drogas , Humanos , Lignanas/farmacologia , Ratos
8.
Phytother Res ; 30(6): 971-80, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26989859

RESUMO

Phytoestrogens are selective estrogen receptor modulators (SERMs) with potential for use in hormone replacement therapy (HRT) to relieve peri/postmenopausal symptoms. This study was aimed at elucidating the molecular mechanisms underlying the SERM properties of the extract of Korean-grown Opuntia ficus-indica (KOFI). The KOFI extract induced estrogen response element (ERE)-driven transcription in breast and endometrial cancer cell lines and the expression of endogenous estrogen-responsive genes in breast cancer cells. The flavonoid content of different KOFI preparations affected ERE-luciferase activities, implying that the flavonoid composition likely mediated the estrogenic activities in cells. Oral administration of KOFI decreased the weight gain and levels of both serum glucose and triglyceride in ovariectomized (OVX) rats. Finally, KOFI had an inhibitory effect on the 17ß-estradiol-induced proliferation of the endometrial epithelium in OVX rats. Our data demonstrate that KOFI exhibited SERM activity with no uterotrophic side effects. Therefore, KOFI alone or in combination with other botanical supplements, vitamins, or minerals may be an effective and safe alternative active ingredient to HRTs, for the management of postmenopausal symptoms. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Opuntia/química , Receptores de Estrogênio/química , Animais , Feminino , Humanos , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Transfecção
9.
Shanghai Kou Qiang Yi Xue ; 23(3): 312-6, 2014 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-25102874

RESUMO

PURPOSE: To discuss the selection of appropriate post and core materials in order to obtain better fracture resistance for thin-walled teeth. METHODS: Ninety maxillary incisors were endodontically treated and the crowns were cut off. Then they were randomly divided into 9 groups. The teeth in the first 4 groups were restored with cast (A1.3 and A1.6) and fiber (B1.3 and B1.6) posts of 1.3 and 1.7 mm diameters. The teeth in the other 5 groups were enlarged to simulate the 1 mm thin-walled teeth and restored with cast (C) and fiber posts. The fiber posts were reconstructed and cemented with Unicem (D1.3 and D1.6) and ParaCore (E1.3 and E1.6). All teeth were restored with full crown, and the fracture resistance and fracture mode were analysed. Statistical analysis was carried out using SPSS 16.0 software package. RESULTS: Largest fracture resistance values (610.2 ± 45.6) N were found in Group A1.3 of ordinary root canals, and no significant difference (P>0.05) existed between Group A1.3, A1.6 and B1.3, B1.6. Group C received the largest fracture resistance value(584.5 ± 121.2) N in thin-walled root canals, and fiber posts reconstructed with ParaCore cement could increase fracture resistance [E1.3,(420.6 ± 95.7) N; E1.6,(517.9 ± 67.2) N], which was significant different compared with D1.3 and D1.6 (P<0.05), but similar to B1.3 and B1.6 in ordinary root canals. CONCLUSIONS: The root can be better preserved by fiber post and the fracture resistance is not affected by the posts with diameters of 1.3 mm and 1.6 mm. The fracture resistance of teeth can be enhanced by reconstruction of root canals with Paracore.


Assuntos
Técnica para Retentor Intrarradicular , Dente não Vital , Resinas Compostas , Coroas , Cimentos Dentários , Análise do Estresse Dentário , Cimentos de Ionômeros de Vidro , Humanos , Incisivo , Fraturas dos Dentes
10.
Anal Biochem ; 385(2): 264-9, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19100707

RESUMO

A kind of nanocomposite with good dispersion in water was prepared through covalent adsorption of ferrocenecarboxaldehyde on multiwalled carbon nanotubes (MWNTs) for electrical communication between glucose oxidase (GOD) and electrode. The ferrocene-modified multiwalled carbon nanotube nanocomposites (MWNTs-Fc) could be conveniently cast on electrode surfaces. With the aid of chitosan, GOD was then immobilized on the nanostructure film to form a reagentless amperometric sensor for glucose determination. FTIR spectra and cyclic voltammetry were used to characterize the nanocomposites. The presence of both ferrocene as mediator of electron transfer and MWNTs as conductor enhanced greatly the enzymatic response to the oxidation of glucose. The novel biosensor exhibited a fast response toward glucose with a detection limit of 3.0 x 10(-6) mol/L and the linear range extended up to 3.8 x 10(-3) mol/L.


Assuntos
Técnicas Biossensoriais/métodos , Compostos Ferrosos/química , Glucose/análise , Nanotubos de Carbono/química , Técnicas Biossensoriais/instrumentação , Quitosana , Eletrodos , Enzimas Imobilizadas , Glucose Oxidase , Metalocenos
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