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1.
Plant Dis ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783584

RESUMO

Euphrates poplar (Populus euphratica Oliv.) constitutes about 61% of the global poplar population, thriving in arid regions of western China (Wu et al. 2023). It plays a crucial role in maintaining ecological balance, securing oasis agriculture, and driving socio-economic progress in the region. During a June 2023 investigation in the P. euphratica forest within the Hotan area of Xinjiang (37°20'21″N, 79°21'15″E), over 12% of the P. euphratica trees displayed branch withering symptoms. The affected trees exhibited cracked bark, trunk decay, darkened coloration, and an eventual black coal-smoke-like appearance. Fungal spores were notably present beneath peeling bark on trunks and main branches. The deep ulcers extended longitudinally into the cambium, leading to tree mortality. In some cases, lateral spread into the sapwood caused dark discoloration of vascular tissue. Twenty diseased branches from various locations were collected and 5-10 mm2 lesions were excised from the edges. These were then surface-disinfected with 75% ethanol for 30 s and 1% sodium hypochlorite for 2 min. After three rinses with sterile distilled water, excess moisture was removed using sterile filter paper, followed by incubating the samples on Potato Dextrose Agar (PDA) medium. Cultures were subsequently grown at 25 ± 1 ℃ under a 12-h photoperiod for three days, thus resulting in the isolation of 25 fungal strains with similar morphological characteristics. All strains displayed rapid colony growth (40 mm/d). On PDA medium, the mycelium initially presented as a white colony, transitioning to an olive-green to greyish color, finally turning dark-grey to black. Colonies generated mycelia that disintegrated into 0- to 1-septate, cylindrical to round, hyaline to brown arthroconidia, occurring singly or in arthric chains, averaging 8.9 ± 2.1 µm × 4.9 ± 1.3 µm, with a length/width ratio of 1.79. Based on morphological characteristics, the isolates were identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers (Crous et al. 2006). Molecular characterization involved amplifying the partial internal transcribed spacer (ITS) region and translation elongation factor 1-α (TEF1-α) and ß-tubulin (TUB2) genes using ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and BT2a/BT2b primers (Glass and Donaldson 1995). Sequences, available in GenBank (ITS: PP033096, PP033097, PP033098; TUB2: PP032812, PP032813, PP032814; TEF1-α: PP032815, PP032816, PP032817), exhibited 99-100% identity with the epitype N. dimidiatum Arp2-D (ITS, MK813852; TUB2, MK816354; TEF1-α, MK816355). Phylogenetic analysis, employing maximum likelihood and Bayesian inference on concatenated ITS-TEF1-TUB, was constructed using IQ-Tree and MrBayes3.2.7, revealing isolates clustering within the N. dimidiatum clade. Three isolates (HY01, HY02, and HY05) from different collection points were chosen for pathogenic investigation. Pathogenicity testing on one-year-old healthy P. euphratica seedlings involved removing a 4-mm-diameter bark plug using a cork borer. A 3-day-cultured N. dimidiatum plug of the same size was inoculated, with a blank PDA as control. The wound was covered with moistened sterile absorbent cotton and finally sealed with parafilm for three days. Experiments were repeated thrice. Symptoms manifested by day 2 post-inoculation, resembling the original symptoms by day 7. In the control group, plants remained healthy. N. dimidiatum was exclusively re-isolated from lesions on inoculated stems, confirmed as N. dimidiatum through morphological characteristics and sequence analysis, aligning with Koch's hypothesis. To our knowledge, this is the first report of N. dimidiatum inducing stem canker on P. euphratica in China. This pathogen has been reported on many tree hosts including citrus (Alananbeh et al., 2020), common fig (Güney et al., 2022), dragon fruit (Salunkhe et al., 2023), and Almond (Nouri et al., 2018). Therefore our findings will serve as a warning for authorities to a potential threat in China's P. euphratica and other trees cultivation. Thus, further epidemiological studies are essential for devising effective management strategies.

2.
Br J Haematol ; 202(4): 840-855, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37365680

RESUMO

Multiple myeloma (MM) is the second most common haematological malignancy. Despite the development of new drugs and treatments in recent years, the therapeutic outcomes of patients are not satisfactory. It is necessary to further investigate the molecular mechanism underlying MM progression. Herein, we found that high E2F2 expression was correlated with poor overall survival and advanced clinical stages in MM patients. Gain- and loss-of-function studies showed that E2F2 inhibited cell adhesion and consequently activated cell epithelial-to-mesenchymal transition (EMT) and migration. Further experiments revealed that E2F2 interacted with the PECAM1 promoter to suppress its transcriptional activity. The E2F2-knockdown-mediated promotion of cell adhesion was significantly reversed by the repression of PECAM1 expression. Finally, we observed that silencing E2F2 significantly inhibited viability and tumour progression in MM cell models and xenograft mouse models respectively. This study demonstrates that E2F2 plays a vital role as a tumour accelerator by inhibiting PECAM1-dependent cell adhesion and accelerating MM cell proliferation. Therefore, E2F2 may serve as a potential independent prognostic marker and therapeutic target for MM.


Assuntos
Mieloma Múltiplo , Humanos , Animais , Camundongos , Mieloma Múltiplo/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Adesão Celular/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Proliferação de Células , Fator de Transcrição E2F2/genética , Fator de Transcrição E2F2/metabolismo
3.
Nature ; 529(7586): 377-82, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26751057

RESUMO

Batteries based on sodium superoxide and on potassium superoxide have recently been reported. However, there have been no reports of a battery based on lithium superoxide (LiO2), despite much research into the lithium-oxygen (Li-O2) battery because of its potential high energy density. Several studies of Li-O2 batteries have found evidence of LiO2 being formed as one component of the discharge product along with lithium peroxide (Li2O2). In addition, theoretical calculations have indicated that some forms of LiO2 may have a long lifetime. These studies also suggest that it might be possible to form LiO2 alone for use in a battery. However, solid LiO2 has been difficult to synthesize in pure form because it is thermodynamically unstable with respect to disproportionation, giving Li2O2 (refs 19, 20). Here we show that crystalline LiO2 can be stabilized in a Li-O2 battery by using a suitable graphene-based cathode. Various characterization techniques reveal no evidence for the presence of Li2O2. A novel templating growth mechanism involving the use of iridium nanoparticles on the cathode surface may be responsible for the growth of crystalline LiO2. Our results demonstrate that the LiO2 formed in the Li-O2 battery is stable enough for the battery to be repeatedly charged and discharged with a very low charge potential (about 3.2 volts). We anticipate that this discovery will lead to methods of synthesizing and stabilizing LiO2, which could open the way to high-energy-density batteries based on LiO2 as well as to other possible uses of this compound, such as oxygen storage.

4.
Biol Chem ; 402(4): 461-468, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33938176

RESUMO

The chemoresistance is one of the major challenges for acute myeloid leukemia (AML) treatment. We found that the expression of histone deacetylase 8 (HDAC8) was increased in daunorubicin (DNR) resistant AML cells, while targeted inhibition of HDAC8 by its specific siRNA or inhibitor can restore sensitivity of DNR treatment . Further, targeted inhibition of HDAC8 can suppress expression of interleukin 6 (IL-6) and IL-8. While recombinant IL-6 (rIL-6) and rIL-8 can reverse si-HDAC8-resored DNR sensitivity of AML cells. Mechanistical study revealed that HDAC8 increased the expression of p65, one of key components of NF-κB complex, to promote the expression of IL-6 and IL-8. It might be due to that HDAC8 can directly bind with the promoter of p65 to increase its transcription and expression. Collectively, our data suggested that HDAC8 promotes DNR resistance of human AML cells via regulation of IL-6 and IL-8.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Daunorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Histona Desacetilases/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas Repressoras/metabolismo , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Histona Desacetilases/genética , Humanos , Interleucina-6/antagonistas & inibidores , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/antagonistas & inibidores , Interleucina-8/genética , Interleucina-8/metabolismo , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , RNA Interferente Pequeno/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Células Tumorais Cultivadas
5.
Hepatology ; 71(1): 76-92, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31215672

RESUMO

Sestrin 3 (Sesn3) belongs to the three-member sestrin protein family. Sestrins have been implicated in antioxidative stress, adenosine monophosphate-activated protein kinase and mammalian target of rapamycin signal transduction, and metabolic homeostasis. However, the role of Sesn3 in the development of nonalcoholic steatohepatitis (NASH) has not been previously studied. In this work, we generated Sesn3 whole-body knockout and liver-specific transgenic mice to investigate the hepatic function of Sesn3 in diet-induced NASH. With only 4 weeks of dietary treatment, Sesn3 knockout mice developed severe NASH phenotype as characterized by hepatic steatosis, inflammation, and fibrosis. Strikingly, after 8-week feeding with a NASH-inducing diet, Sesn3 transgenic mice were largely protected against NASH development. Transcriptomic analysis revealed that multiple extracellular matrix-related processes were up-regulated, including transforming growth factor ß (TGF-ß) signaling and collagen production. Further biochemical and cell biological analyses have illustrated a critical control of the TGF-ß-mothers against decapentaplegic homolog (Smad) pathway by Sesn3 at the TGF-ß receptor and Smad3 levels. First, Sesn3 inhibits the TGF-ß receptor through an interaction with Smad7; second, Sesn3 directly inhibits the Smad3 function through protein-protein interaction and cytosolic retention. Conclusion: Sesn3 is a critical regulator of the extracellular matrix and hepatic fibrosis by suppression of TGF-ß-Smad3 signaling.


Assuntos
Dieta/efeitos adversos , Proteínas de Choque Térmico/fisiologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos
6.
Phys Chem Chem Phys ; 23(28): 15374-15383, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34259266

RESUMO

The use of the conventional pressure-composition-temperature (PCT) method to determine the thermodynamics of metal hydrides is a time-consuming process. This work presents an efficient method based on thermogravimetric analysis (TGA), to characterize the thermodynamic parameters. Through cycling catalyzed magnesium hydride in a TGA apparatus under a flowing gas with a constant hydrogen partial pressure, TGA curves can be used to determine absorption/desorption equilibrium temperatures. Based on the van't Hoff analysis, the reaction enthalpies and entropies can be derived from the equilibrium temperatures as a function of hydrogen pressure. Using the results of this work we calculated the hydrogenation and dehydrogenation enthalpies, which are 79.8 kJ per mol per H2 and 76.5 kJ per mol per H2, respectively. These values are in good agreement with those reported values using the PCT method. These results demonstrate that the TGA can be an efficient and effective method for measuring thermodynamic parameters of metal hydrides.

7.
Luminescence ; 36(3): 721-732, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33300263

RESUMO

In this study, a type of blue-emission fluorescent carbon dot was synthesized using malic acid, urea, and water. This material demonstrates strong stability to heat, ionic strength, and time. It was found that mercury ions can quench the blue fluorescence of the material, and using iodine ions, the fluorescence can be recovered. Hence, we designed an "off-on" mode to detect mercury and iodine ions using the carbon dots. The results showed that this material exhibits good selectivity and recovery rate. Concurrently, imaging experiments showed that this material demonstrates low cytotoxicity and can be used in cell fluorescence imaging. The study concludes that this material has wider application prospects in the future.


Assuntos
Iodo , Mercúrio , Pontos Quânticos , Carbono , Corantes Fluorescentes , Espectrometria de Fluorescência
8.
J Nanosci Nanotechnol ; 19(6): 3487-3494, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30744776

RESUMO

An environment-friendly non-chromium chemical conversion coating was obtained from fluozirconate/fluotitanate acidic solution for the corrosion protection of AA 5083. The surface morphology, composition, electrochemical behavior and corrosion resistance of this coating were investigated. The coating was found to be a homogeneous and dense layer consisting of nano-size particles, of which the major component was compound oxides consisted by Al, Mg, Zr, Ti, F and O. The results of electrochemical measurements, immersion and natural salt spray (NSS) tests demonstrated that the corrosion resistance of the AA 5083 H-116 was improved by the nano-sized non-chromium chemical conversion coating considerably, which was most attributed to the great inhibitive action on the anodic dissolution by acting as a protective barrier layer.

9.
Cell Physiol Biochem ; 51(2): 886-896, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30466095

RESUMO

BACKGROUND/AIMS: Among different molecular candidates, there is growing data to support that long noncoding RNAs (lncRNAs) play a significant role in acute myeloid leukemia (AML). HOXA-AS2 is significantly overexpressed in a variety of tumors and associated with anti-cancer drug resistance, however, little is known regarding the expression and function of HOXA-AS2 in the chemoresistance of AML. In this study, we aimed to determine the role and molecular mechanism of HOXA-AS2 in adriamycin-based chemotherapy resistance in AML cells. METHODS: Quantitative real-time PCR was used to detect HOXA-AS2 expression in the BM samples and ADR cell lines, U/A and T/A cells. Furthermore, the effects of HOXA-AS2 silencing on cell proliferation and apoptosis were assessed in vitro by CCK8 and flow cytometry, and on tumor growth in vivo. Furthermore, bioinformatics online programs predicted and luciferase reporter assay were used to validate the association of HOXA-AS2 and miR-520c-3p in AML. RESULTS: In this study, we showed that HOXA-AS2 is significantly upregulated in BM samples from AML patients after treatment with adriamycin-based chemotherapy and in U/A and T/A cells. Knockdown of HOXA-AS2 inhibited ADR cell proliferation in vitro and in vivo and promoted apoptosis. Bioinformatics online programs predicted that HOXA-AS2 sponge miR-520c-3p at 3'-UTR with complementary binding sites, which was validated using luciferase reporter assay and anti-Ago2 RIP assay. HOXA-AS2 could negatively regulate the expression of miR-520c-3p in ADR cells. S100A4 was predicted as a downstream target of miR-520c-3p, which was confirmed by luciferase reporter assay. CONCLUSION: Our results suggest that HOXA-AS2 plays an important role in the resistance of AML cells to adriamycin. Thus, HOXA-AS2 may represent a therapeutic target for overcoming resistance to adriamycin-based chemotherapy in AML.


Assuntos
Leucemia Mieloide Aguda/patologia , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Proteína A4 de Ligação a Cálcio da Família S100/metabolismo , Regiões 3' não Traduzidas , Animais , Antagomirs/metabolismo , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Masculino , Camundongos , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/uso terapêutico , Proteína A4 de Ligação a Cálcio da Família S100/química , Proteína A4 de Ligação a Cálcio da Família S100/genética
10.
Clin Lab ; 64(11)2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30549992

RESUMO

Background: Castleman disease (CD) is a lymphoproliferative disorder and Langerhans cell histiocytosis (LCH) is a clonal disease of the monocyte-macrophage system. The authors describe a rare case of CD coexistent with LCH at diagnosis in one lymph node. Methods: Hematologic investigation and intrapulmonary mass biopsy were performed. Results: The patient achieved complete remission and, up to now, no signs of recurrence were found. Conclusions: The report about co-existence with CD and LCH will promote correct diagnosis because of the recognition of this rare morphologic combination. An adequate amount of tissue should be obtained to avoid missing the diagnosis.


Assuntos
Hiperplasia do Linfonodo Gigante/complicações , Histiocitose de Células de Langerhans/complicações , Linfonodos/patologia , Biópsia , Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Hiperplasia do Linfonodo Gigante/cirurgia , Histiocitose de Células de Langerhans/diagnóstico por imagem , Histiocitose de Células de Langerhans/cirurgia , Humanos , Linfonodos/diagnóstico por imagem , Masculino , Indução de Remissão , Toracoscopia , Tomografia Computadorizada por Raios X , Adulto Jovem
11.
Clin Lab ; 64(7): 1311-1315, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30146835

RESUMO

BACKGROUND: Diffuse large B cell lymphoma (DLBCL) and follicular cell lymphoma (FL) synchronously occurring in the same individual is unusual. The authors describe a rare case of DLBCL coexisting with FL at diagnosis in a male patient, with intestinal and lymph node involvement. METHODS: Hematologic investigation, intestinal tumor biopsy, bone marrow examination, cytogenetic analysis, and PCR were performed. RESULTS: The patient received three courses of R-CHOP regimen chemotherapy, the mesentery lymph nodes were reduced to 2.7 x 1.4 cm compared to 5.4 x 5.0 cm at diagnosis. However, the mesentery lymph nodes were increased to 4.7 x 3.5 cm after four additional courses R-CHOP treatment. Unfortunately, the patient refused chemotherapy treatment or hematopoietic stem cell transplantation (HSCT) and was lost to follow-up. CONCLUSIONS: The presence of DLBCL coexisting with FL at diagnosis is rare and has generally been the subject of isolated case reports. Further studies are required to better understand the biological insights of the disease and to propose an optimal management strategy for this type of lymphoma.


Assuntos
Linfoma Folicular/diagnóstico , Linfoma Difuso de Grandes Células B/diagnóstico , Adulto , Antígenos CD20/análise , Antígenos CD79/análise , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Linfoma Folicular/complicações , Linfoma Folicular/metabolismo , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Neprilisina/análise , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas c-bcl-6/análise
12.
J Am Chem Soc ; 138(22): 6916-9, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27196140

RESUMO

Reactive metals including Ti, Zr, Hf, and V, among others, have a strong chemical affinity to oxygen, which makes them difficult to produce and costly to use. It is especially challenging to produce pure or metal alloy powders of these elements when extremely low oxygen content is required, because they have high solubility for oxygen, and the solid solution of these metals with oxygen is often more stable thermodynamically than their oxides. We report a novel thermochemical approach to destabilize Ti(O) solid solutions using hydrogen, thus enabling deoxygenation of Ti powder using Mg, which has not been possible before because of the thermodynamic stability of Ti(O) solid solutions relative to MgO. The work on Ti serves as an example for other reactive metals. Both analytical modeling and experimental results show that hydrogen can indeed increase the oxygen potential of Ti-O solid solution alloys; in other words, the stability of Ti-O solid solutions is effectively decreased, thus increasing the thermodynamic driving force for Mg to react with oxygen in Ti. Because hydrogen can be easily removed from Ti by a simple heat treatment, it is used only as a temporary alloying element to destabilize the Ti-O systems. The thermodynamic approach described here is a breakthrough and is applicable to a range of different materials. This work is expected to provide an enabling solution to overcome one of the key scientific and technological hurdles to the additive manufacturing of metals, which is emerging rapidly as the future of the manufacturing industry.

13.
J Transl Med ; 14: 270, 2016 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-27645552

RESUMO

BACKGROUND: Chronic myelogenous leukemia (CML) is a hematological stem cell disorder. Tyrosine kinase inhibitors (TKIs) are the standard treatments for CML, but a number of patients fail to respond effectively due to gene mutations. Celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, has been shown to have anti-tumor effect on solid tumor whereas the anti-CML effect and its underlying mechanism have not been completely elucidated. METHODS: The cytotoxic effects of celecoxib and/or imatinib were evaluated by MTT assay. Cell cycle distribution was examined by propidium iodide (PI) assay. Apoptosis or necrosis was analyzed by Annexin-V/PI, Hoechst 33342 staining and Western blot assays. Autophagy suppression effect of celecoxib was examined by Western blot and LysoTracker probe labelling. Lysosensor probe labelling was used to detect the effect of celecoxib on the lysosomal function. RESULTS: In this study, we found that celecoxib had therapy efficacy in KBM5 and imatinib-resistant KBM5-T315I CML cell lines. Celecoxib caused significant cytotoxic effect in both cell lines, especially in KBM5-T315I cells exposed to celecoxib for 72 h. Moreover, celecoxib induced necrosis and apoptosis while inhibited autophagy in CML cell lines and patient samples. Furthermore, this study demonstrated that celecoxib prevented the autophagic flux by inhibiting lysosome function. Celecoxib was tested in combination with imatinib, demonstrating that celecoxib could strengthen the cytotoxicity of imatinib in imatinib-resistant CML cells. CONCLUSIONS: These findings showed that celecoxib had therapy efficacy on CML cells. And it is first time to demonstrate that celecoxib is an autophagy suppresser and a combination of celecoxib and imatinib might be a promising new therapeutic strategy for imatinib-resistant CML cells.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Celecoxib/farmacologia , Celecoxib/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Adulto , Linhagem Celular Tumoral , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Mesilato de Imatinib/farmacologia , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Masculino , Pessoa de Meia-Idade , Necrose , Estadiamento de Neoplasias
14.
Cell Mol Neurobiol ; 36(1): 121-30, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26271288

RESUMO

Elevated ß-amyloid (Aß) is a hallmark of Alzheimer's disease (AD). Recent evidence has suggested that the receptor of advanced glycation end products (RAGE) is a key target for Aß-induced perturbation in AD, and blockade of RAGE significantly alleviates synaptic injury. Our previous study has suggested that ß-asarone could reduce neuronal apoptosis and improve memory deficits in ß-amyloid precursor protein and presenilin-1 (APP/PS1) double transgenic AD-model mice. In the present study, we evaluated the effects of ß-asarone on amyloidosis in APP/PS1 mice. We found that the survival of neurons of APP/PS1 mice was improved by ß-asarone, meanwhile, ß-asarone decreased Aß deposition and down-regulated Aß1-42 levels in cortex and hippocampus of APP/PS1 mice brain. Interestingly, the level of RAGE was also significantly down-regulated by ß-asarone. Our findings suggest that ß-asarone might be effective for the treatment of AD, and the decreasing effects of ß-asarone on Aß might associate with its down-regulation of RAGE.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Amiloidose/tratamento farmacológico , Anisóis/uso terapêutico , Regulação para Baixo/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Derivados de Alilbenzenos , Doença de Alzheimer/complicações , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Amiloidose/complicações , Amiloidose/patologia , Animais , Anisóis/administração & dosagem , Anisóis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/patologia , Modelos Animais de Doenças , Hipocampo/patologia , Camundongos Transgênicos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Placa Amiloide/complicações , Placa Amiloide/tratamento farmacológico , Placa Amiloide/patologia , Presenilina-1/metabolismo
15.
Nanotechnology ; 26(16): 164003, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25829367

RESUMO

Uniformly dispersed Pd nanoparticles on ZnO-passivated porous carbon were synthesized via an atomic layer deposition (ALD) technique, which was tested as a cathode material in a rechargeable Li-O2 battery, showing a highly active catalytic effect toward the electrochemical reactions-in particular, the oxygen evolution reaction. Transmission electron microscopy (TEM) showed discrete crystalline nanoparticles decorating the surface of the ZnO-passivated porous carbon support in which the size could be controlled in the range of 3-6 nm, depending on the number of Pd ALD cycles performed. X-ray absorption spectroscopy (XAS) at the Pd K-edge revealed that the carbon-supported Pd existed in a mixed phase of metallic palladium and palladium oxide. The ZnO-passivated layer effectively blocks the defect sites on the carbon surface, minimizing the electrolyte decomposition. Our results suggest that ALD is a promising technique for tailoring the surface composition and structure of nanoporous supports for Li-O2 batteries.

16.
Sci Rep ; 14(1): 15482, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969688

RESUMO

With the progression of many shale gas wells in the Sichuan-Chongqing region of China into the middle and late stages of exploitation, the problem of sand production in these wells is a primary factor influencing production. Failure to implement measures to remove sand from the gas wells will lead to a sharp decline in production after a certain period of exploitation. Moreover, As the amount of sand produced in the well increases, the production layer will be potentially buried by sand. To boost the production of shale gas wells in the Sichuan-Chongqing region and improve production efficiency, a novel downhole jet sand-washing device has been developed. Upon analyzing the device's overall structure, it is revealed that the device adopts a structural design integrating a jet pump with an efficient sand- washing nozzle, providing dual capabilities for jet sand- washing and sand conveying via negative pressure. To enhance the sand- washing and unblocking performance of the device, various sand- washing fluids and the structures of different sand- washing nozzles are compared for selection, aiming to elevate the device's sand- washing and unblocking performance from a macro perspective. Subsequently, drawing on simulation and internal flow field analysis of the device's sand- washing and unblocking process through CFD and the control variable method, it is ultimately found that the length diameter ratio of the cylindrical segment of the nozzle outlet, the outlet diameter, and the contraction angle of the nozzle greatly influence the device's sand- washing and unblocking performance. And the optimum ranges for the length-diameter ratio of the cylindrical segment of the nozzle outlet, the outlet diameter, the contraction angle of the nozzle, and the inlet diameter are 2 to 4, 6 mm to 10 mm, 12° to 16°, and 18 mm and 22 mm, respectively. The findings of the research not only provide new insights into existing sand removal processes but also offer a novel structure for current downhole sand removal devices and a specific range for the optimal size of the nozzle.

17.
J Mol Model ; 30(5): 142, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642186

RESUMO

CONTEXT: Hydrogen has emerged as a promising clean energy carrier, underscoring the imperative need to comprehend its adsorption mechanisms. This study delves into the magnetic and electronic properties of Co-Mo-P clusters, aiming to unveil their catalytic potential in hydrogen production. Employing density functional theory (DFT), we optimized cluster configurations and scrutinized their magnetic behaviors. Our investigation unveiled 16 stable configurations of the ConMoP (n = 1 ~ 5) cluster, predominantly in steric forms. The magnetic attributes were primarily ascribed to the d orbitals of Co metal atoms, with Co3MoP exhibiting exceptional magnetic characteristics. Analysis of density of state diagrams revealed the prevalence of spin-up α-electrons in d orbitals, while spin-down ß-electrons attenuated overall magnetic properties. Localized orbital (LOL) analysis highlighted stable covalent bonds within the clusters, affirming their catalytic potential. Orbital delocalization index (ODI) analysis revealed diverse spatial distribution ranges for orbitals across different configurations, suggesting a progressive attenuation of off-domain properties with increasing cluster size. Furthermore, infrared spectroscopy unveiled distinct vibrational peaks in various configurations, indicative of unique infrared activities. These findings contribute to a nuanced theoretical understanding of Co-Mo-P clusters and pave the path for future research aimed at augmenting their catalytic efficiency in hydrogen production. This study underscores the viability of Co-Mo-P clusters as alternatives to conventional Pt catalysts, offering insights into the design of novel materials for sustainable energy applications. Further research is warranted to explore the behavior of the Co-Mo-P system under diverse reaction conditions, fostering advancements in materials and energy science. METHODS: In this study, we harnessed the ConMoP (n = 1 ~ 5) cluster as a simulation platform for probing the local structure of the material. Our aim was to scrutinize the magnetism, electronic characteristics influenced by the varying metal atoms within these clusters. A systematic exploration involved incrementing the number of metal atoms and expanding the cluster size to elucidate the corresponding property variations. Density functional theory (DFT) calculations were pivotal to our methodology, employing the B3LYP hybrid functional implemented in the Gaussian 16 software package. The ConMoP (n = 1 ~ 5) cluster underwent optimization calculations and vibrational analysis at the def2-tzvp quantization level, yielding optimized configurations with diverse spin multiplet degrees. To comprehensively characterize and visually represent the stability, electronic features, and catalytic attributes of these configurations, we employed a suite of computational tools. Specifically, quantum chemistry software GaussView and wave function analysis software Multiwfn played integral roles. Through the integrated use of these computational tools, we acquired valuable insights into the magnetism, electronic characteristics of the ConMoP (n = 1 ~ 5) cluster, shedding light on their dependency on distinct metal atoms.

18.
Mater Horiz ; 11(8): 1908-1922, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38334032

RESUMO

Transgranular brittle fracture is the dominant failure mode of brittle materials, including ceramics and ceramic matrix composites. However, strengthening these materials without sacrificing their toughness has been a big challenge. In this study, an innovative approach is proposed to achieve coordinated strengthening and toughening of ceramics-based composites by introducing specific ductile coherent nanoparticles into ceramic grains. As an example, the WC-Co cemented tungsten carbides were used to demonstrate how this brittle material can achieve ultrahigh strength without losing toughness by seeding metallic nanoparticles inside WC grains. The mechanisms for inducing the formation and modulating the amount, size, and distribution of such nanophase within the ceramic grains were disclosed. The fraction of transgranular ruptures of the brittle ceramic phase was reduced significantly due to the presence of the ductile coherent in-grain nanoparticles. Both the strength and strain limit of the cemented carbides were remarkably increased compared to their counterparts reported in the literature. The coordinated strengthening and toughening strategy proposed in this work is applicable to a broad range of ceramics and ceramic matrix composites to obtain superior comprehensive mechanical properties.

19.
Materials (Basel) ; 17(3)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38591504

RESUMO

A new strategy for the high-throughput characterization of the mechanical homogeneity of metallurgical materials is proposed. Based on the principle of hydrostatic transmission and the synergistic analysis of the composition, microstructure, defects, and surface profile of the chosen material, the microstrain characteristics and changes in surface roughness after isostatic pressing were analyzed. After isostatic pressing, two types of microstrains were produced: low microstrain (surface smoothening with decreasing roughness) and large microstrain (surface roughening with increasing roughness). Furthermore, the roughness of the roughened microregions could be further classified based on the strain degree. The phenomenon of weak-interface damage with a large microstrain (plastic deformation, cleavage fracture, and tearing near nonmetallic inclusions) indicated that the surface microstrain analysis could be a new method of high-throughput characterization for microregions with relatively poor micromechanical properties. In general, the effect of isostatic pressing on the surface microstrain of heat-resistant steel provides a promising strategy for achieving high-throughput screening and statistically characterizing microregions with poor micromechanical properties, such as microregions containing microcracks, nonmetallic inclusions, pores, and other surface defects.

20.
J Am Chem Soc ; 135(30): 10982-5, 2013 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-23855837

RESUMO

Efforts to thermodynamically destabilize magnesium hydride (MgH2), so that it can be used for practical hydrogen storage applications, have been a difficult challenge that has eluded scientists for decades. This letter reports that MgH2 can indeed be destabilized by forming solid solution alloys of magnesium with group III and IVB elements, such as indium. Results of this research showed that the equilibrium hydrogen pressure of a Mg-0.1In alloy is 70% higher than that of pure MgH2. The temperature at 1 bar hydrogen pressure (T1bar) of Mg-0.1In alloy was reduced to 262.9 °C from 278.9 °C, which is the T1bar of pure MgH2. Furthermore, the kinetic rates of dehydrogenation of Mg-0.1In alloy hydride doped with a titanium intermetallic (TiMn2) catalyst were also significantly improved compared with those of MgH2.

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