Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Small Methods ; : e2301709, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38678540

RESUMO

Robust synthesis of ultrafine metal nanoparticles (ufMNPs) below 5 nm with clean surfaces and strong optical absorption in the visible spectral range is challenging due to their instability originating from large surface-to-volume ratios. This work reports a general strategy involving two sequential steps: i) loading metal precursor ions onto the surface of silica nanospheres (SiOx NSs) by forming a uniform coating of metal oxyhydroxide [MOy(OH)z] through preferred surface acid-base reactions and ii) thermally reducing MOy(OH)z in forming gas at elevated temperatures to form ufMNPs evenly dispersed on the surface of SiOx NSs. The capability of this synthesis strategy is verified by loading ufMNPs of various transition metals and bimetallic combinations onto the SiOx NSs. The ufMNPs exhibit strong optical absorption enhanced by the optical scattering resonances in the SiOx NSs, which generate intense electric fields near the surface of the SiOx NSs. The SiOx NSs also support stabilizing the ufMNPs, which do not need additional organic capping reagents. The successful synthesis of SiOx-NS-supported ufMNPs with clean surfaces and enhanced optical absorption is promising for exploring the photocatalytic properties of ufMNPs.

2.
Plant Physiol Biochem ; 208: 108475, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38430786

RESUMO

Saline-alkali stress significantly affects the growth and yield of alfalfa (Medicago sativa L.). Organic acid secretion is crucial in alleviating abiotic stress-induced damage in plants. In this study, we evaluated the contents of the major organic acids secreted by the roots of tolerant (ZD) and sensitive (LYL) varieties of alfalfa under saline-alkali stress and investigated the effects of these organic acids on the growth, and physiological functions of alfalfa. Our results indicated that the oxalic acid (OA) content was the highest among the organic acids secreted from alfalfa roots under saline-alkali stress, and oxalic acid content was the most significantly different between the two varieties, ZD and LYL, compared to the contents of the other organic acids. Oxalic acid alleviated the inhibition of alfalfa growth caused by saline-alkali stress, improved photosynthetic characteristics, reduced the accumulation of reactive oxygen species, and increased the activity of antioxidant enzymes and content of osmoregulatory substances. Furthermore, oxalic acid resulted in significantly increased expression of genes involved in photosynthesis and antioxidant system in alfalfa under saline-alkali stress. This study revealed the effects of oxalic acid secreted by the root system on stress-related physiological processes, providing valuable insights into the functions of root secretions in plant saline-alkali resistance.


Assuntos
Antioxidantes , Medicago sativa , Antioxidantes/metabolismo , Medicago sativa/genética , Álcalis/metabolismo , Fotossíntese , Oxalatos/metabolismo , Oxalatos/farmacologia
3.
Chem Soc Rev ; 53(9): 4400-4433, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38497773

RESUMO

The theoretically infinite compositional space of high-entropy alloys (HEAs) and their novel properties and applications have attracted significant attention from a broader research community. The successful synthesis of high-quality single-phase HEA nanoparticles represents a crucial step in fully unlocking the potential of this new class of materials to drive innovations. This review analyzes the various methods reported in the literature to identify their commonalities and dissimilarities, which allows categorizing these methods into five general strategies. Physical minimization of HEA metals into HEA nanoparticles through cryo-milling represents the typical top-down strategy. The counter bottom-up strategy requires the simultaneous generation and precipitation of metal atoms of different elements on growing nanoparticles. Depending on the metal atom generation process, there are four synthesis strategies: vaporization of metals, burst reduction of metal precursors, thermal shock-induced reduction of metal precursors, and solvothermal reduction of metal precursors. Comparisons among the methods within each strategy, along with discussions, provide insights and guidance for achieving the robust synthesis of HEA nanoparticles.

4.
Nanoscale Horiz ; 9(4): 627-636, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38334479

RESUMO

Selective hydrogenation of CO2 to yield CH4 relies on the appropriate catalysts that can facilitate the cleavage of CO bonds and dissociative adsorption of H2. Ultrafine Rh nanoparticles loaded on silica nanospheres were used as a class of photocatalysts to significantly improve the selectivity and reaction rate of producing CH4 from the mixture of CO2 and H2 under the illumination of a broadband visible light source. The intense light scattering resonances in the silica nanospheres generate strong electric fields near the silica surface to enhance the light absorption power in the supported ultrafine Rh nanoparticles, promoting the efficiency of hot electron generation in the Rh nanoparticles. The interaction of the hot electrons with the adsorbate species on the Rh nanoparticle surface weakens the C-O bond to facilitate the deoxygenation of CO2, favoring the production of CH4 with a unity selectivity at a faster rate in the presence of surface adsorbed hydrogen (H*). The systematic studies on reaction kinetics and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy under different conditions, including various temperatures, illumination powers, and feeding gas compositions, reveal the reaction mechanism responsible for CO2 methanation and the role of photoillumination.

5.
Plant Physiol Biochem ; 207: 108338, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38244388

RESUMO

Alfalfa (Medicago sativa L.) is a leguminous forage widely grown worldwide. Saline and alkaline stress can affect its development and yield. To elucidate the physiological mechanisms of alfalfa in response to saline and alkaline stress, we investigated the growth and physiological and metabolomic changes in alfalfa under saline (100 mM NaCl) and alkaline (100 mM Na2CO3, NaHCO3) stress. At the same Na+ concentration, alkaline stress caused more damage than that caused by saline stress. A total of 65 and 124 metabolites were identified in response to saline and alkaline stress, respectively. Determination of gene expression, enzyme activity, substance content, and KEGG enrichment analysis in key pathways revealed that alfalfa responded to saline stress primarily by osmoregulation and TCA cycle enhancement. Flavonoid synthesis, TCA cycle, glutamate anabolism, jasmonate synthesis, and cell wall component synthesis increased as responses to alkaline stress. This study provides important resources for breeding saline-alkaline-resistant alfalfa.


Assuntos
Medicago sativa , Melhoramento Vegetal , Medicago sativa/genética , Cloreto de Sódio/farmacologia , Cloreto de Sódio/metabolismo , Sódio/metabolismo , Metabolômica , Estresse Fisiológico , Regulação da Expressão Gênica de Plantas
6.
Front Plant Sci ; 14: 1293167, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38078103

RESUMO

Abiotic stresses, such as high salinity, pose a significant threat to plant growth and development, reducing crop yield and quality. Calcineurin B-like (CBL) proteins serve as crucial calcium sensors in plant responses to diverse environmental stresses. However, the CBL family in sweet cherry has not been identified at the genome-wide level, and the regulatory role of CBL proteins in cherry plants' salt response is unclear. Here, we identified 10 CBL family genes (PavCBLs) from the Prunus avium genome and cloned seven of them. We comprehensively analyzed PavCBL genes for collinearity, phylogenetic relationships, gene structure, and conserved motifs. Expression analysis revealed significant induction of transcription under abiotic stress, with PavCBL4 displaying the most substantial expression change. Additionally, we identified PavCBL4 as a PavSOS2 (Salt Overly Sensitive 2)-interacting protein through Y2H and Split-LUC assays. Subcellular localization analysis indicated that PavCBL4 is present in both the cytoplasm and nucleus. Functional assessment of PavCBL4 in the PavCBL4-overexpressing transgenic 'Gisela 6' plants showed its positive role in enhancing salt tolerance in cherry plants. Measurements of Na+ content and antioxidant enzyme activity under salt stress indicated that PavCBL4 functions positively by inhibiting Na+ accumulation and promoting ROS scavenging in response to salt stress. These findings lay the groundwork for a deeper understanding of the molecular mechanisms underlying PavCBL-mediated salt tolerance in sweet cherry.

7.
Sheng Wu Gong Cheng Xue Bao ; 39(4): 1731-1746, 2023 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-37154335

RESUMO

Adiponectin receptor 1 (AdipoR1) and Adiponectin receptor 2 (AdipoR2) can bind to adiponectin (AdipoQ) secreted by adipose tissue to participate in various physiological functions of the body. In order to explore the role of AdipoR1 and AdipoR2 in amphibians infected by Aeromonas hydrophila (Ah), the genes adipor1 and adipor2 of Rana dybowskii were cloned by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed by bioinformatics. The tissue expression difference of adipor1 and adipor2 was analyzed by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR), and an inflammatory model of R. dybowskii infected by Ah was constructed. The histopathological changes were observed by hematoxylin-eosin staining (HE staining); the expression profiles of adipor1 and adipor2 after infection were dynamically detected by qRT-PCR and Western blotting. The results show that AdipoR1 and AdipoR2 are cell membrane proteins with seven transmembrane domains. Phylogenetic tree also shows that AdipoR1 and AdipoR2 cluster with the amphibians in the same branch. qRT-PCR and Western blotting results show that adipor1 and adipor2 were up-regulated at different levels of transcription and translation upon Ah infection, but the response time and level were different. It is speculated that AdipoR1 and AdipoR2 participate in the process of bacterial immune response, providing a basis for further exploring the biological functions of AdipoR1 and AdipoR2 in amphibians.


Assuntos
Adiponectina , Receptores de Adiponectina , Animais , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Filogenia , Adiponectina/genética , Adiponectina/metabolismo , Clonagem Molecular , Ranidae/genética
8.
Plant Physiol Biochem ; 200: 107787, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37247557

RESUMO

Myo-inositol oxygenase (MIOX), a pivotal enzyme in the myo-inositol oxygenation pathway, catalyzes the cleavage of myo-inositol to UDP-glucuronic acid and plays a major role in plant adaptation to abiotic stress factors. However, studies pertaining to the MIOX gene family in alfalfa (Medicago sativa L.) are lacking. Therefore, this study characterized ten MsMIOX genes in the alfalfa genome. These genes were divisible into two classes distributed over three chromosomes and produced 12 pairs of fragment repeats and one pair of tandem repeats. Physicochemical properties, subcellular location, protein structure, conserved motifs, and gene structure pertinent to these MsMIOX genes were analyzed. Construction of a phylogenetic tree revealed that similar gene structures and conserved motifs were present in the same MsMIOX groups. Analysis of cis-acting elements revealed the presence of stress- and hormone-induced expression elements in the promoter regions of the MsMIOX genes. qRT-PCR analysis revealed that MsMIOX genes could be induced by various abiotic stress factors, such as salt, saline-alkali, drought, and cold. Under such conditions, MIOX activity in alfalfa was significantly increased. Heterologous MsMIOX2 expression in yeast enhanced salt, saline-alkali, drought, and cold tolerance. Overexpression of MsMIOX2 in the hairy roots of alfalfa decreased O2- and H2O2 content and enhanced the abiotic stress tolerance. This study offers comprehensive perspectives on the functional features of the MsMIOX family and provides a candidate gene for improving the abiotic stress tolerance of alfalfa.


Assuntos
Inositol Oxigenase , Medicago sativa , Medicago sativa/genética , Medicago sativa/metabolismo , Inositol Oxigenase/genética , Inositol Oxigenase/metabolismo , Peróxido de Hidrogênio/metabolismo , Filogenia , Estresse Fisiológico/genética , Cloreto de Sódio/farmacologia , Inositol/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo
9.
Front Plant Sci ; 14: 1079292, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36860903

RESUMO

Color is an essential appearance characteristic of sweet cherry (Prunus avium L.) fruits and mainly determined by anthocyanin. Temperature plays an important role in the regulation of anthocyanin accumulation. In this research, anthocyanin, sugar, plant hormone and related gene expression were analyzed using physiological and transcriptomic methods in order to reveal the effects of high temperature on fruit coloring and the related mechanism. The results showed that high temperature severely inhibited anthocyanin accumulation in fruit peel and slowed the coloring process. The total anthocyanin content in fruit peel increased by 455% and 84% after 4 days of normal temperature treatment (NT, 24°C day/14°C night) and high temperature treatment (HT, 34°C day/24°C night), respectively. Similarly, the contents of 8 anthocyanin monomers were significantly higher in NT than in HT. HT also affected the levels of sugars and plant hormones. The total soluble sugar content increased by 29.49% and 16.81% in NT and HT, respectively, after 4 days of treatment. The levels of ABA, IAA and GA20 also increased in both the two treatments but more slowly in HT. Conversely, the contents of cZ, cZR and JA decreased more rapidly in HT than in NT. The results of the correlation analysis showed that the ABA and GA20 contents were significantly correlated with the total anthocyanin contents. Further transcriptome analysis showed that HT inhibited the activation of structural genes in anthocyanin biosynthesis as well as the repression of CYP707A and AOG, which dominated the catabolism and inactivation of ABA. These results indicate that ABA may be a key regulator in the high-temperature-inhibited fruit coloring of sweet cherry. High temperature induces higher ABA catabolism and inactivation, leading to lower ABA levels and finally resulting in slow coloring.

10.
Plant Dis ; 107(10): 3269-3272, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36947840

RESUMO

Sweet cherry virescence phytoplasma strain SCV-TA2020, a related strain of 'Candidatus Phytoplasma ziziphi', is a pathogen associated with sweet cherry virescence disease in China. Here, we provide the first-draft genome sequence of SCV-TA2020, which consists of 775,344 bases, with a GC content of 23.21%. This will provide a reference for understanding the host selection and diversity of host-specific symptoms of 16SrV-B subgroup phytoplasmas.


Assuntos
Phytoplasma , Prunus avium , Phytoplasma/genética , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Filogenia , Doenças das Plantas , China
11.
Chem Commun (Camb) ; 59(24): 3546-3549, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36892408

RESUMO

Triphenylphosphine oxide (TPPO) and triphenylphosphine (TPP) can form a complex in solution, promoting visible light absorption to trigger electron transfer within the complex and generate radicals. Subsequent radical reactions with thiols enable desulfurization to produce carbon radicals that react with aryl alkenes to yield new C-C bonds. Since ambient oxygen can easily oxidize TPP to TPPO, the reported method requires no explicit addition of a photocatalyst. This work highlights the promise of using TPPO as a catalytic photo-redox mediator in organic synthesis.

12.
Nanomaterials (Basel) ; 12(23)2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36500939

RESUMO

Eliminating clogging in capillary tube reactors is critical but challenging for enabling continuous-flow microfluidic synthesis of nanoparticles. Creating immiscible segments in a microfluidic flow is a promising approach to maintaining a continuous flow in the microfluidic channel because the segments with low surface energy do not adsorb onto the internal wall of the microchannel. Herein we report the spontaneous self-agglomeration of reduced graphene oxide (rGO) nanosheets in polyol flow, which arises because the reduction of graphene oxide (GO) nanosheets by hot polyol changes the nanosheets from hydrophilic to hydrophobic. The agglomerated rGO nanosheets form immiscible solid segments in the polyol flow, realizing the liquid-solid segmented flow to enable clogging aversion in continuous-flow microfluidic synthesis. Simultaneous reduction of precursor species in hot polyol deposits nanocrystals uniformly dispersed on the rGO nanosheets even without surfactant. Cuprous oxide (Cu2O) nanocubes of varying edge lengths and ultrafine metal nanoparticles of platinum (Pt) and palladium (Pd) dispersed on rGO nanosheets have been continuously synthesized using the liquid-solid segmented flow microfluidic method, shedding light on the promise of microfluidic reactors in synthesizing functional nanomaterials.

13.
J Phys Chem Lett ; 13(38): 8921-8927, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36130195

RESUMO

Photolysis reaction pathways of [Au(III)Cl4]- in aqueous solution have been investigated by time-resolved X-ray absorption spectroscopy. Ultraviolet excitation directly breaks the Au-Cl bond in [Au(III)Cl4]- to form [Au(II)Cl3]- that becomes highly reactive within 79 ps. Disproportionation of [Au(II)Cl3]- generates [Au(I)Cl2]-, which is stable for ≤10 µs. In contrast, intense near-infrared lasers photolyze water to generate hydrated electrons, which then reduce [Au(III)Cl4]- to [Au(II)Cl3]- at 5 ns. Hydrated electrons further induce a chain reaction from [Au(II)Cl3]- to [Au(0)Cl]- by successively removing one Cl-. The zero-valency Au anions quickly polymerize and condense to form Au nanoparticles, which become the dominating product after 400 s. Our results reveal that the condensation of zero-valency Au starts with dimerization of gold clusters coordinated with chloride ions rather than direct condensation of pristine Au atoms.


Assuntos
Ouro , Nanopartículas Metálicas , Ânions , Cloretos , Ouro/química , Água/química , Espectroscopia por Absorção de Raios X , Raios X
14.
Nanoscale Horiz ; 6(7): 568-573, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-33997878

RESUMO

The involvement of heterogeneous solid/liquid reactions in growing colloidal nanoparticles makes it challenging to quantitatively understand the fundamental steps that determine nanoparticles' growth kinetics. A global optimization protocol relying on simulated annealing fitting and the LSW growth model is developed to analyze the evolution data of colloidal silver nanoparticles synthesized from a microwave-assisted polyol reduction reaction. Fitting all data points of the entire growth process determines with high fidelity the diffusion coefficient of precursor species and the heterogeneous reduction reaction rate parameters on growing silver nanoparticles, which represent the principal functions to determine the growth kinetics of colloidal nanoparticles. The availability of quantitative results is critical to understanding the fundamentals of heterogeneous solid/liquid reactions, such as identifying reactive species and reaction activation energy barriers.

15.
Oncol Lett ; 21(4): 288, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732364

RESUMO

Long non-coding RNAs (lncRNAs) have been confirmed to participate in cancer regulation, including oral squamous cell carcinoma (OSCC). The aim of the present study was to investigate the role of UASR1 in OSCC. The expression levels of UASR1, miR-375 and JAK2 were detected in OSCC tissues by reverse transcriptase quantitative PCR. The targets of UASR1 were predicted by IntaRNA. Colony formation and CCK-8 assays were conducted to estimate cell proliferation. Western blotting was used to detect the protein expression of JAK2. The results demonstrated that UASR1 was upregulated in OSCC tissues compared with non-tumor tissues, and the high level of UASR1 expression was associated with poor overall survival. UASR1 is predicted to interact with miR-375 and the interaction was confirmed by Dual-luciferase activity assay. However, overexpression of UASR1 and miR-375 did not affect the expression of each other. Instead, upregulation of JAK2, a target of miR-375, was observed after the overexpression of UASR1 in OSCC cells. Moreover, overexpression of UASR1 attenuated the inhibitory effects of miR-375 on the expression of JAK2 and cell proliferation. Therefore, UASR1 is overexpressed in OSCC and regulates cancer cell proliferation by regulating the miR-375/JAK2 axis.

16.
J Biochem Mol Toxicol ; 35(4): e22689, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33347680

RESUMO

The present study examines the chemopreventive role of [6]-gingerol, an active component of ginger, on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis models. The HBP has been developed with an addition of 0.5% of DMBA to the HBP area three times per week, up to the end of the 16th experimental week. At the end of the experiment, we noticed 100% tumor incidence and precancerous lesions, such as dysplasia, hyperplasia, keratosis, and well-differentiated squamous cell carcinoma, in DMBA-induced HBP. Furthermore, we observed that [6]-gingerol inhibited the increased thiobarbituric acid-reactive substances and decreased antioxidant levels in DMBA-induced hamsters. Moreover, [6]-gingerol inhibits DMBA-exposed over expression of inflammatory markers (inducible nitric oxide synthase, interleukin [IL]-1ß, IL-6, cyclooxygenase-2, and tumor necrosis factor-α) and cell proliferation markers (cyclin D1, proliferating cell nuclear antigen); induces proapoptotic markers in HBP. Nuclear factor erythroid-2-related factor-2 (Nrf2) is a major antioxidant transcription factor, which regulates the antioxidant gene-dependent scavenge of tumor proliferation and apoptosis. Overexpression of Nrf2 signaling plays a pivotal role and can be a novel target in preventing carcinogenesis. In this study, [6]-gingerol restores the DMBA-induced depletion of Nrf2 signaling and thereby prevents buccal pouch carcinogenesis in hamsters. These results point out that [6]-gingerol impedes the responses of inflammatory and cell proliferation-associated progression of cancer through the action of Nrf2 signaling.


Assuntos
9,10-Dimetil-1,2-benzantraceno/toxicidade , Carcinogênese , Catecóis/farmacologia , Proliferação de Células/efeitos dos fármacos , Álcoois Graxos/farmacologia , Mucosa Bucal/metabolismo , Neoplasias Bucais , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas de Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Carcinogênese/induzido quimicamente , Carcinogênese/metabolismo , Carcinogênese/patologia , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Masculino , Mesocricetus , Mucosa Bucal/patologia , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia
17.
Mol Med Rep ; 22(2): 1129-1136, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32626995

RESUMO

Temporomandibular disorder (TMD) is a complicated and multi­factorial disease related to inflammation and cartilage destruction. Intra­articular injection of xanthan gum (XG) has been demonstrated to protect the joint cartilage and reduce osteoarthritis progression. However, the role and mechanism of XG in TMD is still unclear. In the present study, chondrocytes were isolated from rats and identified by immunofluorescence. Cells were stimulated by XG or interleukin (IL)­1ß. Cell viability was analyzed by MTT assay. Tumor necrosis factor α (TNF­α) and IL­6 levels were determined by ELISA. The expression of monocyte chemoattractive protein­1 (MCP­1), inducible nitric oxide synthase (iNOS), collagens, matrix metalloproteinases (MMPs), peptidyl­prolyl isomerase 1 (Pin1) and phosphorylated nuclear factor κB (NF­κB) p65 (p­p65) was analyzed by quantitative PCR or western blotting. MMP activity was assessed by gelatin zymography. Compared with the control, XG treatment partially reversed the IL­1ß­reduced cell viability. In addition, IL­1ß stimulation increased inflammatory cytokine expression, including TNF­α, IL­6 secretion, MCP­1 and iNOS expression, whereas XG treatment reduced the expression of these inflammatory cytokines compared with that of the IL­1ß­stimulated cells. Additionally, XG increased the expression of collagen, but reduced MMP expression and activity as compared with that in the IL­1ß group. In addition, XG treatment prevented the IL­1ß­increased Pin1 and p­p65 expression. These data suggested that XG reduced the expression of inflammatory cytokines and may maintain the balance between collagens and MMPs partially through the Pin1/NF­κB signaling pathway in IL­1ß­stimulated temporomandibular chondrocytes. Therefore, XG may be useful in the treatment of TMD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Condrócitos/efeitos dos fármacos , Citocinas/metabolismo , Polissacarídeos Bacterianos/farmacologia , Fator de Transcrição RelA/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/metabolismo , Interleucina-1beta/farmacologia , Masculino , Metaloproteinases da Matriz/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Transtornos da Articulação Temporomandibular/induzido quimicamente , Transtornos da Articulação Temporomandibular/tratamento farmacológico
18.
Ying Yong Sheng Tai Xue Bao ; 31(4): 1121-1129, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32530186

RESUMO

To investigate the effects of H2S on mitochondrial functions under low temperature stress, we analyzed the effects of 0.05 mmol·L-1 NaHS and 15 µmmol·L-1 HT (hypotaurine and H2S scavenger) on mitochondria antioxidant enzyme activities and mitochondrial permeability transition pore, mitochondrial membrane fluidity, mitochondrial membrane potential, Cyt c/a ratio and H+-ATPase activity in sweet cherry stigma and ovary with sweet cherry variety Zaodaguo under -2 ℃ low temperature stress. The results showed that low temperature stress increased the concentrations of mitochondrial H2O2 and MDA, enhanced the mitochondrial membrane permeability, but decreased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase acti-vity. Application of NaHS at 0.05 mmol·L-1 could effectively reduce the concentrations of H2O2 and MDA, and keep higher activities of SOD, POD and CAT of mitochondrial for longer time. Furthermore, application of 0.05 mmol·L-1 NaHS could decrease mitochondrial membrane permeability while increase mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity in stigma and ovary under low temperature stress. The effects of NaHS were completely offset by HT addition. The results suggested that exogenous H2S could alleviate the oxidative damage on stigma and ovary stress through decreasing H2O2 accumulation, regulating mitochondria antioxidant system, increasing H+-ATPase activity, and mitigating mitochondria function under low temperature.


Assuntos
Sulfeto de Hidrogênio , Prunus avium , Feminino , Peróxido de Hidrogênio , Mitocôndrias , Ovário , Estresse Oxidativo , Temperatura
19.
Cancer Manag Res ; 12: 3401-3407, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32494204

RESUMO

INTRODUCTION: The oncogenic role of lncRNA LUADT1 has been investigated only in lung cancer. This study aimed to investigate the role of LUADT1 in oral squamous cell carcinoma (OSCC). PATIENTS AND METHODS: The expression levels of LUADT1 in paired OSCC and non-tumor tissues from OSCC patients were determined by RT-qPCR. A 5-year follow-up study was performed to analyze the prognostic value of LUADT1 for OSCC. Dual-luciferase assay and overexpression experiments were performed to assess the interactions among LUADT1, miR-34a and GASL1. Cell proliferation was analyzed by cell proliferation assay. RESULTS: In this study, we found that LUADT1 was upregulated in OSCC and predicted poor survival. LUADT1 was predicted to interact with miR-34a, which was confirmed by dual-luciferase activity assay. However, overexpression experiments showed that they did not affect the expression of each other. Interestingly, overexpression of LUADT1 resulted in upregulation of GAS1, a target of miR-34a. Cell proliferation assay revealed that overexpression of LUADT1 and GAS1 resulted in promoted cell proliferation. MiR-34a played an opposite role and reversed the effects of LUADT1 overexpression. CONCLUSION: LUADT1 may promote OSCC proliferation by regulating miR-34a/GAS1 axis.

20.
Nano Lett ; 20(4): 2806-2811, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32197043

RESUMO

Silver nanostructures with hierarchical porosities of multiple length scales have been synthesized through electrochemical reduction of silver benzenethiolate nanoboxes. The porous Ag nanostructures exhibit superior catalytic performance toward electrochemical reduction of CO2. The Faradaic efficiency of reducing CO2 to CO can be close to 100% at high cathodic potentials, benefiting from the readsorbed benzenethiolate ions on the Ag surface that can suppress the hydrogen evolution reaction (HER). Density functional theory calculations using the SCAN functional reveal that the disfavored H binding on the benzenethiolate-modified Ag surface is responsible for inhibiting the HER. The mass-specific activity of CO2 reduction can be over 500 A/g because the multiple-scale porosities maximize the diffusion of reactive species to and away from the Ag surface. The unique multiscale porosities and surface modification of the as-synthesized Ag nanostructures make them a class of promising catalysts for electrochemical reduction of CO2 in protic electrolytes to achieve maximum activity and selectivity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...