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1.
Materials (Basel) ; 16(20)2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37895734

RESUMEN

In this paper, we investigate the structural, microstructural, dielectric, and energy storage properties of Nd and Mn co-doped Ba0.7Sr0.3TiO3 [(Ba0.7Sr0.3)1-xNdxTi1-yMnyO3 (BSNTM) ceramics (x = 0, 0.005, and y = 0, 0.0025, 0.005, and 0.01)] via a defect dipole engineering method. The complex defect dipoles (MnTi"-VO∙∙)∙ and (MnTi"-VO∙∙) between acceptor ions and oxygen vacancies capture electrons, enhancing the breakdown electric field and energy storage performances. XRD, Raman, spectroscopy, XPS, and microscopic investigations of BSNTM ceramics revealed the formation of a tetragonal phase, oxygen vacancies, and a reduction in grain size with Mn dopant. The BSNTM ceramics with x = 0.005 and y = 0 exhibit a relative dielectric constant of 2058 and a loss tangent of 0.026 at 1 kHz. These values gradually decreased to 1876 and 0.019 for x = 0.005 and y = 0.01 due to the Mn2+ ions at the Ti4+- site, which facilitates the formation of oxygen vacancies, and prevents a decrease in Ti4+. In addition, the defect dipoles act as a driving force for depolarization to tailor the domain formation energy and domain wall energy, which provides a high difference between the maximum polarization of Pmax and remnant polarization of Pr (ΔP = 10.39 µC/cm2). Moreover, the complex defect dipoles with optimum oxygen vacancies in BSNTM ceramics can provide not only a high ΔP but also reduce grain size, which together improve the breakdown strength from 60.4 to 110.6 kV/cm, giving rise to a high energy storage density of 0.41 J/cm3 and high efficiency of 84.6% for x = 0.005 and y = 0.01. These findings demonstrate that defect dipole engineering is an effective method to enhance the energy storage performance of dielectrics for capacitor applications.

2.
Materials (Basel) ; 15(24)2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36556714

RESUMEN

High-Mn lightweight steel, Fe-0.9C-29Mn-8Al, was manufactured using steelmaking, ingot-making, forging, and rolling processes. After the final rolling process, a typical austenite single phase was observed on all sides of the thick plate. The microstructural changes after annealing and aging heat-treatments were observed, using optical and transmission electron microscopy. The annealed coupon exhibited a typical austenite single phase, including annealing twins in several grains; the average grain size was 153 µm. After aging heat treatment, κ-carbide was observed within the grains and on the grain boundaries. Additionally, the effect of aging heat treatment on the mechanical properties was analyzed, using a tensile test. The fine κ-carbide that precipitated within the grains in the aged coupon improved the 0.2% offset yield and the tensile stresses, as compared to the as-annealed coupon. To estimate the applicability of high-Mn lightweight steel for low-pressure (LP) steam turbine blades, a low-cycle fatigue (LCF) test was carried out at room temperature. At a total strain amplitude of 0.5 to 1.2%, the LCF life of high-Mn lightweight steel was approximately three times that of 12% Cr steel, which is used in commercial LP steam turbine blades. The LCF behavior of high-Mn lightweight steel followed the Coffin-Manson equation. The LCF life enhancement in the high-Mn lightweight steel results from the planar dislocation gliding behavior.

3.
Sci Rep ; 12(1): 7204, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-35504925

RESUMEN

To learn spatiotemporal representations and anomaly predictions from geophysical data, we propose STANet, a spatiotemporal neural network with a trainable attention mechanism, and apply it to El Niño predictions for long-lead forecasts. The STANet makes two critical architectural improvements: it learns spatial features globally by expanding the network's receptive field and encodes long-term sequential features with visual attention using a stateful long-short term memory network. The STANet conducts multitask learning of Nino3.4 index prediction and calendar month classification for predicted indices. In a comparison of the proposed STANet performance with the state-of-the-art model, the accuracy of the 12-month forecast lead correlation coefficient was improved by 5.8% and 13% for Nino3.4 index prediction and corresponding temporal classification, respectively. Furthermore, the spatially attentive regions for the strong El Niño events displayed spatial relationships consistent with the revealed precursor for El Niño occurrence, indicating that the proposed STANet provides good understanding of the spatiotemporal behavior of global sea surface temperature and oceanic heat content for El Niño evolution.


Asunto(s)
El Niño Oscilación del Sur , Redes Neurales de la Computación , Predicción , Aprendizaje
4.
Materials (Basel) ; 15(10)2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35629672

RESUMEN

Z-type hexagonal ferrites have recently received attention for their room-temperature magnetoelectric (ME), which is activated when the temperature at which the transverse-conical spin-state transitions to a ferrimagnetic state is increased. The changes in the magnetic domain structure at the transition have been well-documented; however, they are still not understood in detail. In the present study, Lorentz transmission electron microscopy (TEM) analysis combined with an in situ heating experiment was conducted to demonstrate the shift in magnetic domain structure during the transition from the transverse-conical spin arrangement to a ferrimagnetic spin order. The dynamics of the magnetic domain structure changes with the increasing temperature were acquired in real-time. At 490 K, the magnetization transition from the transverse-conical spin state to the ferromagnetic state was demonstrated. Cross-tie domain walls formed during the magnetic transition process. The increased effect of the demagnetizing field applied to the 180° magnetic domains was caused by a lower magnetocrystalline anisotropy (MCA) at the easy axis of magnetization.

5.
Materials (Basel) ; 15(7)2022 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-35407995

RESUMEN

Real-time structural changes in Na-ß″-alumina were observed in situ using transmission electron microscopy (TEM) with electron beam irradiation. Na-ß″-alumina has been widely investigated as a solid electrolyte material for sodium-sulfur secondary batteries owing to its high ionic conductivity. This high conductivity is known to be due to the Na+ ions on the loosely packed conduction planes of Na-ß″-alumina. In the present study, we acquired real-time videos of the generation of spinel blocks caused by the conduction of Na+ ions. In addition, by observing Na extraction during electron beam irradiation, we experimentally confirmed that spinel block generation originates from the Na+ ion conduction, which has been a subject of recent debate.

6.
Biomol Ther (Seoul) ; 30(1): 80-89, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34887366

RESUMEN

The targeting of DNA methylation in cancer using DNA hypomethylating drugs has been well known to sensitize cancer cells to chemotherapy and immunotherapy by affecting multiple pathways. Herein, we investigated the combinational effects of DNA hypomethylating drugs and ionizing radiation (IR) in human sarcoma cell lines both in vitro and in vivo. Clonogenic assays were performed to determine the radiosensitizing properties of two DNA hypomethylating drugs on sarcoma cell lines we tested in this study with multiple doses of IR. We analyzed the effects of 5-aza-dC or SGI-110, as DNA hypomethylating drugs, in combination with IR in vitro on the proliferation, apoptosis, caspase-3/7 activity, migration/invasion, and Western blotting using apoptosis- or autophagy-related factors. To confirm the combined effect of DNA hypomethylating drugs and IR in our in vitro experiment, we generated the sarcoma cells in nude mouse xenograft models. Here, we found that the combination of DNA hypomethylating drugs and IR improved anticancer effects by inhibiting cell proliferation and by promoting synergistic cell death that is associated with both apoptosis and autophagy in vitro and in vivo. Our data demonstrated that the combination effects of DNA hypomethylating drugs with radiation exhibited greater cellular effects than the use of a single agent treatment, thus suggesting that the combination of DNA hypomethylating drugs and radiation may become a new radiotherapy to improve therapeutic efficacy for cancer treatment.

7.
ACS Sens ; 6(12): 4461-4470, 2021 12 24.
Artículo en Inglés | MEDLINE | ID: mdl-34878775

RESUMEN

The rapid and unexpected spread of SARS-CoV-2 worldwide has caused unprecedented disruption to daily life and has brought forward critical challenges for public health. The disease was the largest cause of death in the United States in early 2021. Likewise, the COVID-19 pandemic has highlighted the need for rapid and accurate diagnoses at scales larger than ever before. To improve the availability of current gold standard diagnostic testing methods, the development of point-of-care devices that can maintain gold standard sensitivity while reducing the cost and providing portability is much needed. In this work, we combine the amplification capabilities of reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) techniques with high-sensitivity end-point detection of crumpled graphene field-effect transistors (cgFETs) to develop a portable detection cell. This electrical detection method takes advantage of the ability of graphene to adsorb single-stranded DNA due to noncovalent π-π bonds but not double-stranded DNA. These devices have demonstrated the ability to detect the presence of the SARS-CoV-2 virus in a range from 10 to 104 copies/µL in 20 viral transport medium (VTM) clinical samples. As a result, we achieved 100% PPV, NPV, sensitivity, and specificity with 10 positive and 10 negative VTM clinical samples. Further, the cgFET devices can differentiate between positive and negative VTM clinical samples in 35 min based on the Dirac point shift. Likewise, the improved sensing capabilities of the crumpled gFET were compared with those of the traditional flat gFET devices.


Asunto(s)
Técnicas Biosensibles , COVID-19 , Grafito , Humanos , Pandemias , SARS-CoV-2 , Sensibilidad y Especificidad
8.
J Ginseng Res ; 45(5): 591-598, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34803429

RESUMEN

BACKGROUND: Hematopoiesis is the production of blood cells from hematopoietic stem cells (HSCs) that reside in the bone marrow. Cyclophosphamide (CTX) is a chemotherapy drug that suppresses the immune system. Korean Red Ginseng (KRG) and Colla corii asini (CCA) have been traditionally used for boosting the immune system. METHODS: HSCs in the bone marrow, and immune cell subtype in splenocytes, PBMCs, and thymocytes were investigated. Serum levels of hematopoietic-related markers were analyzed using ELISA. Protein expression in spleen tissue was analyzed using western blot analysis. Hematoxylin & eosin staining in the femurs of mice were also conducted. RESULTS: The combination of KRG and CCA with a ratio of 3:2 increased HSCs, CD3 and CD8+ T cells in the circulation, and CD3 T cells in the spleen. A ratio of 2:3 (KRG:CCA) increased the thymic regulatory T cells and recovered the CD3 T cells in the spleen and circulation while recovering proteins in the JAK-STAT pathway in the spleen. Overall, blood cell population and differentiating factors vital for cell differentiation were also significantly recovered by all combinations especially in ratios of 3:2 and 2:3. CONCLUSION: A ratio of 3:2 (KRG:CCA) is the most ideal combination as it recovered the HSC population in the bone marrow of mice.

9.
Sci Rep ; 11(1): 14468, 2021 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-34262073

RESUMEN

We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe-Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe-Mn-Al-C alloys exhibited a superior strength-ductility balance enabled by the recovery of the strain hardening rate. To understand the relation between the κ-carbides and strain hardening recovery, dislocation gliding in the aged alloys during plastic deformation was analyzed through in situ tensile transmission electron microscopy (TEM). The in situ TEM results confirmed the particle shearing mechanism leads to planar dislocation gliding. During deformation of the 100 h-aged alloy, some gliding dislocations were strongly pinned by the large κ-carbide blocks and were prone to cross-slip, leading to the activation of multiple slip systems. The abrupt decline in the dislocation mean free path was attributed to the activation of multiple slip systems, resulting in the rapid saturation of the strain hardening recovery. It is concluded that the planar dislocation glide and sequential activation of slip systems are key to induce strain hardening recovery in polycrystalline metals. Thus, if a microstructure is designed such that dislocations glide in a planar manner, the strain hardening recovery could be utilized to obtain enhanced mechanical properties of the material.

10.
Artículo en Inglés | MEDLINE | ID: mdl-33953788

RESUMEN

Background and Objective. Epimedium koreanum Nakai is a medicinal plant known for its health beneficial effects on impotence, arrhythmia, oxidation, aging, osteoporosis, and cardiovascular diseases. However, there is no report available that shows its effects on platelet functions. Here, we elucidated antiplatelet and antithrombotic effects of ethyl acetate fraction of E. koreanum. Methodology. We analyzed the antiplatelet properties using standard in vitro and in vivo techniques, such as light transmission aggregometry, scanning electron microscopy, intracellular calcium mobilization measurement, dense granule secretion, and flow cytometry to assess integrin α IIb ß 3 activation, clot retraction, and Western blot, on washed platelets. The antithrombotic effects of E. koreanum were assessed by arteriovenous- (AV-) shunt model in rats, and its effects on hemostasis were analyzed by tail bleeding assay in mice. Key Results. E. koreanum inhibited platelet aggregation in agonist-stimulated human and rat washed platelets, and it also reduced calcium mobilization, ATP secretion, and TXB2 formation. Fibrinogen binding, fibronectin adhesion, and clot retraction by attenuated integrin α IIb ß 3-mediated inside-out and outside-in signaling were also decreased. Reduced phosphorylation of extracellular signal-regulated kinases (ERK), Akt, PLCγ2, and Src was observed. Moreover, the fraction inhibited thrombosis. HPLC results revealed that the fraction predominantly contained icariin. Conclusion and Implications. E. koreanum inhibited platelet aggregation and thrombus formation by attenuating calcium mobilization, ATP secretion, TXB2 formation, and integrin α IIb ß 3 activation. Therefore, it may be considered as a potential candidate to treat and prevent platelet-related cardiovascular disorders.

12.
Mol Brain ; 14(1): 73, 2021 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-33892766

RESUMEN

Loss-of-function mutations in the human oligophrenin-1 (OPHN1) gene cause intellectual disability, a prevailing neurodevelopmental condition. However, the role OPHN1 plays during neuronal development is not well understood. We investigated the role of the Drosophila OPHN1 ortholog Graf in the development of the mushroom body (MB), a key brain structure for learning and memory in insects. We show that loss of Graf causes abnormal crossing of the MB ß lobe over the brain midline during metamorphosis. This defect in Graf mutants is rescued by MB-specific expression of Graf and OPHN1. Furthermore, MB α/ß neuron-specific RNA interference experiments and mosaic analyses indicate that Graf acts via a cell-autonomous mechanism. Consistent with the negative regulation of epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) signaling by Graf, activation of this pathway is required for the ß-lobe midline-crossing phenotype of Graf mutants. Finally, Graf mutants have impaired olfactory long-term memory. Our findings reveal a role for Graf in MB axon development and suggest potential neurodevelopmental functions of human OPHN1.


Asunto(s)
Axones/metabolismo , Proteínas Portadoras/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Memoria a Largo Plazo/fisiología , Cuerpos Pedunculados/metabolismo , Olfato/fisiología , Animales , Encéfalo/metabolismo , Proteínas Portadoras/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Endocitosis , Epistasis Genética , Receptores ErbB/metabolismo , Proteínas Fluorescentes Verdes/metabolismo , Ligandos , Metamorfosis Biológica , Mutación/genética , Regiones Promotoras Genéticas/genética , Transducción de Señal
13.
J Cell Biol ; 220(5)2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33683284

RESUMEN

Mutations in the human ALS2 gene cause recessive juvenile-onset amyotrophic lateral sclerosis and related motor neuron diseases. Although the ALS2 protein has been identified as a guanine-nucleotide exchange factor for the small GTPase Rab5, its physiological roles remain largely unknown. Here, we demonstrate that the Drosophila homologue of ALS2 (dALS2) promotes postsynaptic development by activating the Frizzled nuclear import (FNI) pathway. dALS2 loss causes structural defects in the postsynaptic subsynaptic reticulum (SSR), recapitulating the phenotypes observed in FNI pathway mutants. Consistently, these developmental phenotypes are rescued by postsynaptic expression of the signaling-competent C-terminal fragment of Drosophila Frizzled-2 (dFz2). We further demonstrate that dALS2 directs early to late endosome trafficking and that the dFz2 C terminus is cleaved in late endosomes. Finally, dALS2 loss causes age-dependent progressive defects resembling ALS, including locomotor impairment and brain neurodegeneration, independently of the FNI pathway. These findings establish novel regulatory roles for dALS2 in endosomal trafficking, synaptic development, and neuronal survival.


Asunto(s)
Esclerosis Amiotrófica Lateral/metabolismo , Endosomas/metabolismo , Endosomas/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Densidad Postsináptica/metabolismo , Densidad Postsináptica/fisiología , Esclerosis Amiotrófica Lateral/genética , Animales , Transporte Biológico/fisiología , Muerte Celular/genética , Supervivencia Celular/genética , Células Cultivadas , Drosophila/genética , Drosophila/metabolismo , Drosophila/fisiología , Endosomas/genética , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Mutación/genética , Fenotipo , Densidad Postsináptica/genética , Proteínas de Unión al GTP rab5/genética , Proteínas de Unión al GTP rab5/metabolismo
14.
Phytother Res ; 35(3): 1621-1633, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33150724

RESUMEN

The consequences of increased industrialization increased the risk of asthma and breathing difficulties due to increased particulate matter in the air. We aim to investigate the therapeutic properties of Hypericum ascyron L. extract (HAE) in airway inflammation and unravel its mechanism of action. We conducted nitric oxide and cell viability assay, real-time PCR and western blot analyses along with in vitro studies. in vivo studies include a model of coal fly ash and diesel exhaust particle (CFD)-induced airway inflammation in mice. HAE reduced coal fly ash (CFA)-induced nitric oxide secretion without exhibiting cytotoxicity in MH-S cells. HAE also reduced the mRNA expression of pro-inflammatory cytokines and reduced the expression of proteins in the NFκB and MAPK pathways. In a mice model of CFD-induced airway inflammation, HAE effectively reduced neutrophil infiltration in bronchoalveolar lavage fluid (BALF) and increased the amount of T cells in the BALF, lungs, and blood while reducing all other immune cell subtypes to reduce airway inflammatory response. CXCL-1, IL-17, MIP-2, and TNF-α expression in the BALF were also reduced. HAE effectively reduced MIP-2 and TNF-α mRNA expression in the lung tissue of mice. In a nutshell, HAE is effective in preventing airway inflammation induced by CFA in MH-S cells, as well as inflammation induced by CFD in mice.


Asunto(s)
Hypericum/química , Inflamación/tratamiento farmacológico , Material Particulado/química , Animales , Modelos Animales de Enfermedad , Inflamación/inducido químicamente , Ratones
15.
J Ginseng Res ; 44(6): 833-842, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33192127

RESUMEN

BACKGROUND: Ulcerative colitis (UC) is a commonly encountered large intestine disease in the contemporary world that terminates into colorectal cancer; therefore, the timely treatment of UC is of major concern. Panax ginseng Meyer is an extensively consumed herbal commodity in South East Asian countries, especially Korea. It exhibits a wide range of biologically beneficial qualities for almost head-to-toe ailments in the body. Epimedium koreanum Nakai (EKN) is also a widely used traditional Korean herbal medicine used for treating infertility, rheumatism, and cardiovascular diseases. MATERIALS AND METHODS: Separately the anti-inflammatory activities of both red ginseng extracts (RGEs) and EKNs had been demonstrated in the past in various inflammatory models; however, we sought to unravel the anti-inflammatory activities of the combination of these two extracts in dextran sulfate sodium (DSS)-induced ulcerative colitis in mice model because the allopathic remedies for UC involve more side effects than benefits. RESULTS: Our results have shown that the combination of RGE + EKN synergistically alleviated the macroscopic lesions in DSS-induced colitic mice such as colon shortening, hematochezia, and weight loss. Moreover, it restored the histopathological lesions in mice and decreased the levels of pro-inflammatory mediators and cytokines through the repression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP-3) expression. In vitro, this combination also reduced the magnitude of nitric acid (NO), pro-inflammatory mediators and cytokine through NF-κB and mitogen-activated protein kinase (MAPK) pathways in RAW 264.7 mouse macrophage cells. CONCLUSION: In the light of these findings, we can endorse this combination extract as a functional food for the prophylactic as well as therapeutic treatment of UC in humans together with allopathic remedies.

16.
Molecules ; 25(22)2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-33182623

RESUMEN

Ginseng is a vastly used herbal supplement in Southeast Asian countries. Red ginseng extract enriched with Rg3 (Rg3-RGE) is a formula that has been extensively studied owing to its various biological properties. Persicaria tinctoria (PT), belonging to the Polygonaceae family, has also been reported for its anti-inflammatory properties. Ulcerative colitis (UC) is inflammation of the large intestine, particularly in the colon. This disease is increasingly common and has high probability of relapse. We investigated, separately and in combination, the effects of Rg3-RGE and PT using murine exemplary of UC induced by DSS (Dextran Sulfate Sodium). For in vitro and in vivo experiments, nitric oxide assay, qRT-Polymerase Chain Reaction (PCR), Western blot, ulcerative colitis introduced by DSS, Enzyme Linked Immunosorbent Assay (ELISA), and flow cytometry analysis were performed. The results obtained demonstrate that treatment with Rg3-RGE + PT showed synergism to suppress inflammation (in vitro) in RAW 264.7 cells via mitogen-activated protein kinase and nuclear factor κB pathways. Moreover, in C57BL/6 mice, this mixture exhibits strong anti-inflammatory effects in restoring colon length, histopathological damage, pro-inflammatory mediators, and cytokines amount, and decreasing levels of NLRP3 inflammasome (in vivo). Our results recommend that this mixture can be used for the prevention of UC as a prophylactic/therapeutic supplement.


Asunto(s)
Caryophyllales/química , Colitis Ulcerosa/tratamiento farmacológico , Panax/química , Extractos Vegetales/farmacología , Balance Th1 - Th2 , Animales , Antiinflamatorios , Ensayo de Inmunoadsorción Enzimática , Inflamación , Mediadores de Inflamación/metabolismo , Sistema de Señalización de MAP Quinasas , Masculino , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/química , Células RAW 264.7 , Transducción de Señal
17.
Molecules ; 25(20)2020 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-33081281

RESUMEN

A 'remedy for all' natural product widely known in the Korean Peninsula is called Panax Ginseng Meyer. Globalization represents a persistent risk to the ozone layer, leading to bountiful amounts of Ultra-Violet B beams (UVB). The variety in human skin hues is ascribed to the characteristic color called Melanin. However, Melanin overproduction due to UVB beams promotes skin staining and tumorigenesis, a process called photo aging, which damages skin quality. To assess the effects of Korean Red Ginseng Oil (KGO) on photo aging, the murine melanoma cell lines B16/F10 were used in vitro and HRM-2 hairless mice exposed to UVB were studied in vivo. Our results revealed that KGO reduced tyrosinase activity and melanin production in B16/F10 cells along with the suppression of upstream factors involved in the melanin production pathway, both transcriptionally and transitionally. In the in vivo studies, KGO suppressed the expression of Matrix Metalloproteinase (MMP) and Interleukins along with a reduction of depth in wrinkle formation and reduced collagen degradation. Moreover, the feed intake and feed efficiency ratio that decreased as a result of UVB exposure was also improved by KGO treatment. In light of our results, we conclude that KGO can have considerable benefits due to its various properties of natural skin enhancement.


Asunto(s)
Carcinogénesis/efectos de los fármacos , Melanoma Experimental/tratamiento farmacológico , Panax/química , Aceites de Plantas/farmacología , Animales , Carcinogénesis/efectos de la radiación , Fibroblastos/efectos de los fármacos , Humanos , Melaninas/biosíntesis , Melaninas/efectos de la radiación , Ratones , Ratones Pelados , Ozono/efectos adversos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Aceites de Plantas/química , Piel/efectos de los fármacos , Piel/metabolismo , Rayos Ultravioleta/efectos adversos
18.
Sci Rep ; 10(1): 12140, 2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32699336

RESUMEN

Steel is the global backbone material of industrialized societies, with more than 1.8 billion tons produced per year. However, steel-containing structures decay due to corrosion, destroying annually 3.4% (2.5 trillion US$) of the global gross domestic product. Besides this huge loss in value, a solution to the corrosion problem at minimum environmental impact would also leverage enhanced product longevity, providing an immense contribution to sustainability. Here, we report a leap forward toward this aim through the development of a new family of low-density stainless steels with ultra-high strength (> 1 GPa) and high ductility (> 35%). The alloys are based on the Fe-(20-30)Mn-(11.5-12.0)Al-1.5C-5Cr (wt%) system and are strengthened by dispersions of nano-sized Fe3AlC-type κ-carbide. The alloying with Cr enhances the ductility without sacrificing strength, by suppressing the precipitation of κ-carbide and thus stabilizing the austenite matrix. The formation of a protective Al-rich oxide film on the surface lends the alloys outstanding resistance to pitting corrosion similar to ferritic stainless steels. The new alloy class has thus the potential to replace commercial stainless steels as it has much higher strength at similar formability, 17% lower mass density and lower environmental impact, qualifying it for demanding lightweight, corrosion resistant, high-strength structural parts.

19.
Front Pharmacol ; 11: 698, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32508642

RESUMEN

BACKGROUND: The prevalence of cardiovascular diseases (CVDs) is increasing at a high rate, and the available treatment options, sometimes, have complications which necessitates the need to develop safer and efficacious approaches. Ethnomedicinal applications reportedly reduce CVD risk. Ulmus parvifolia Jacq. (Ulmaceae) commonly known as Chinese Elm or Lacebark Elm, is native to China, Japan, and Korea. It exhibits anti-inflammatory, antiviral, and anticancer properties, but its anti-platelet properties have not yet been elucidated. PURPOSE: To investigate the pharmacological anti-platelet and anti-thrombotic effects of U. parvifolia bark extract. STUDY DESIGN AND METHODS: Human and rat washed platelets were prepared; light transmission aggregometry and scanning electron microscopy was performed to assess platelet aggregation and the change in platelet shape, respectively. Intracellular calcium mobilization, ATP release, and thromboxane-B2 production were also measured. Integrin αIIbß3 activation was analyzed in terms of fibrinogen binding, fibronectin adhesion, and clot retraction. The expression of MAPK, Src, and PI3K/Akt pathway proteins was examined. Cyclic nucleotide signaling pathway was evaluated via cAMP elevation and VASP phosphorylation. Anti-thrombotic activity of the extract was evaluated in vivo using an arteriovenous shunt rat model, whereas its effect on hemostasis in mice was assessed via bleeding time assay. RESULTS: U. parvifolia extract significantly inhibited human and rat platelet aggregation in a dose-dependent manner along with inhibition of calcium mobilization, dense granule secretion, and TxB2 production. Integrin αIIbß3 mediated inside-out and outside-in signaling events, as evidenced by the inhibition of fibrinogen binding, fibronectin adhesion, and clot retraction. The extract significantly reduced phosphorylation of Src, MAPK (ERK, JNK, and p38MAPK), and PI3K/Akt pathway proteins. Cyclic-AMP levels were elevated in U. parvifolia-treated platelets, while PKAαßγ and VASPser157 phosphorylation was enhanced. U. parvifolia reduced thrombus weight in rats and moderately increased bleeding time in mice. CONCLUSION: U. parvifolia modulates platelet responses and inhibit thrombus formation by regulating integrin αIIbß3 mediated inside-out and outside-in signaling events and cAMP signaling pathway.

20.
J Med Food ; 23(3): 312-318, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32191579

RESUMEN

The aim of this study was to investigate the efficacy of an ethanol extract of Physalis alkekengi (PA) and its mechanistic pathway of action at the molecular level for its antiobesity properties. Four-week old male Institute of Cancer Research (ICR) mice were acclimatized for a week before starting the high-fat diet (HFD) for 2 weeks to induce obesity, followed by 8 more weeks of oral administration of 10 mg/kg orlistat and 300 mg/kg of PA extract, along with HFD. Body weights of the mice and feed and water intake were recorded weekly. After a total of 12 weeks, mice were euthanized, and blood, liver, and adipose tissues were harvested for further analysis. Administration of PA extract inhibited the progression of obesity by reducing weight gain, weight of adipose tissue, and normalizing serum triglyceride, glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, alanine aminotransferase, and aspartate aminotransferase. PA extract prevented the progression of nonalcoholic steatohepatitis induced by HFD and prevented the enlargement of liver. Phosphorylation of adenosine monophosphate-activated protein kinase α increased while phosphorylation of acetyl-CoA carboxylase was reduced. The browning gene uncoupling protein 1 expression was also increased by PA extract treatment. Our findings revealed that the antiobesity properties of PA extract may be mediated by browning of white adipose tissue.


Asunto(s)
Tejido Adiposo Blanco/metabolismo , Fármacos Antiobesidad/administración & dosificación , Obesidad/tratamiento farmacológico , Physalis/química , Extractos Vegetales/administración & dosificación , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Animales , Dieta Alta en Grasa/efectos adversos , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Obesidad/genética , Obesidad/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
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