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1.
Nature ; 592(7854): 376-380, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33854251

RESUMEN

The collective dynamics of topological structures1-6 are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions3,4 have not only deepened our understanding of many-body physics but also offered potential applications in data processing and storage7. Topological structures constructed from electrical polarization, rather than electron spin, have recently been realized in ferroelectric superlattices5,6, and these are promising for ultrafast electric-field control of topological orders. However, little is known about the dynamics underlying the functionality of such complex extended nanostructures. Here, using terahertz-field excitation and femtosecond X-ray diffraction measurements, we observe ultrafast collective polarization dynamics that are unique to polar vortices, with orders-of-magnitude higher frequencies and smaller lateral size than those of experimentally realized magnetic vortices3. A previously unseen tunable mode, hereafter referred to as a vortexon, emerges in the form of transient arrays of nanoscale circular patterns of atomic displacements, which reverse their vorticity on picosecond timescales. Its frequency is considerably reduced (softened) at a critical strain, indicating a condensation (freezing) of structural dynamics. We use first-principles-based atomistic calculations and phase-field modelling to reveal the microscopic atomic arrangements and corroborate the frequencies of the vortex modes. The discovery of subterahertz collective dynamics in polar vortices opens opportunities for electric-field-driven data processing in topological structures with ultrahigh speed and density.

2.
J Biol Chem ; 300(5): 107273, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38588806

RESUMEN

The stability of ribosomal DNA (rDNA) is maintained through transcriptional silencing by the NAD+-dependent histone deacetylase Sir2 in Saccharomyces cerevisiae. Alongside proteostasis, rDNA stability is a crucial factor regulating the replicative lifespan of S. cerevisiae. The unfolded protein response (UPR) is induced by misfolding of proteins or an imbalance of membrane lipid composition and is responsible for degrading misfolded proteins and restoring endoplasmic reticulum (ER) membrane homeostasis. Recent investigations have suggested that the UPR can extend the replicative lifespan of yeast by enhancing protein quality control mechanisms, but the relationship between the UPR and rDNA stability remains unknown. In this study, we found that the deletion of ARV1, which encodes an ER protein of unknown molecular function, activates the UPR by inducing lipid bilayer stress. In arv1Δ cells, the UPR and the cell wall integrity pathway are activated independently of each other, and the high osmolarity glycerol (HOG) pathway is activated in a manner dependent on Ire1, which mediates the UPR. Activated Hog1 translocates the stress response transcription factor Msn2 to the nucleus, where it promotes the expression of nicotinamidase Pnc1, a well-known Sir2 activator. Following Sir2 activation, rDNA silencing and rDNA stability are promoted. Furthermore, the loss of other ER proteins, such as Pmt1 or Bst1, and ER stress induced by tunicamycin or inositol depletion also enhance rDNA stability in a Hog1-dependent manner. Collectively, these findings suggest that the induction of the UPR enhances rDNA stability in S. cerevisiae by promoting the Msn2-Pnc1-Sir2 pathway in a Hog1-dependent manner.


Asunto(s)
ADN Ribosómico , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Respuesta de Proteína Desplegada , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , ADN Ribosómico/metabolismo , ADN Ribosómico/genética , Membrana Dobles de Lípidos/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/genética , Nicotinamidasa/metabolismo , Nicotinamidasa/genética , Sirtuina 2/metabolismo , Sirtuina 2/genética , Proteínas Reguladoras de Información Silente de Saccharomyces cerevisiae/metabolismo , Proteínas Reguladoras de Información Silente de Saccharomyces cerevisiae/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Retículo Endoplásmico/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Glicoproteínas de Membrana
3.
Nat Mater ; 23(1): 108-115, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37919351

RESUMEN

Multi-metal oxides in general and perovskite oxides in particular have attracted considerable attention as oxygen evolution electrocatalysts. Although numerous theoretical studies have been undertaken, the most promising perovskite-based catalysts continue to emerge from human-driven experimental campaigns rather than data-driven machine learning protocols, which are often limited by the scarcity of experimental data on which to train the models. This work promises to break this impasse by demonstrating that active learning on even small datasets-but supplemented by informative structural-characterization data and coupled with closed-loop experimentation-can yield materials of outstanding performance. The model we develop not only reproduces several non-obvious and actively studied experimental trends but also identifies a composition of a perovskite oxide electrocatalyst exhibiting an intrinsic overpotential at 10 mA cm-2oxide of 391 mV, which is among the lowest known of four-metal perovskite oxides.

4.
Nano Lett ; 24(21): 6417-6424, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38710072

RESUMEN

The functional properties of complex oxides, including magnetism and ferroelectricity, are closely linked to subtle structural distortions. Ultrafast optical excitations provide the means to manipulate structural features and ultimately to affect the functional properties of complex oxides with picosecond-scale precision. We report that the lattice expansion of multiferroic BiFeO3 following above-bandgap optical excitation leads to distortion of the oxygen octahedral rotation (OOR) pattern. The continuous coupling between OOR and strain was probed using time-resolved X-ray free-electron laser diffraction with femtosecond time resolution. Density functional theory calculations predict a relationship between the OOR and the elastic strain consistent with the experiment, demonstrating a route to employing this approach in a wider range of systems. Ultrafast control of the functional properties of BiFeO3 thin films is enabled by this approach because the OOR phenomena are related to ferroelectricity, and via the Fe-O-Fe bond angles, the superexchange interaction between Fe atoms.

5.
J Am Chem Soc ; 146(18): 12556-12564, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38660792

RESUMEN

Transition metal nitride (TMN)-based nanostructures have emerged as promising materials for diverse applications in electronics, photonics, energy storage, and catalysis due to their highly desirable physicochemical properties. However, synthesizing TMN-based nanostructures with designed compositions and morphologies poses challenges, especially in the solution phase. The cation exchange reaction (CER) stands out as a versatile postsynthetic strategy for preparing nanostructures that are otherwise inaccessible through direct synthesis. Nevertheless, exploration of the CER in TMNs lags behind that in metal chalcogenides and metal phosphides. Here, we demonstrate cation exchange in colloidal metal nitride nanocrystals, employing Cu3N nanocrystals as starting materials to synthesize Ni4N and CoN nanocrystals. By controlling the reaction conditions, Cu3N@Ni4N and Cu3N@CoN core@shell heterostructures with tunable compositions can also be obtained. The Ni4N and CoN nanocrystals are evaluated as catalysts for the electrochemical oxygen evolution reaction (OER). Remarkably, CoN nanocrystals demonstrate superior OER performance with a low overpotential of 286 mV at 10 mA·cm-2, a small Tafel slope of 89 mV·dec-1, and long-term stability. Our CER approach in colloidal TMNs offers a new strategy for preparing other metal nitride nanocrystals and their heterostructures, paving the way for prospective applications.

6.
Microvasc Res ; 153: 104655, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38232898

RESUMEN

OBJECTIVE: This study aimed to explore the effects of sedative doses of propofol and isoflurane on microcirculation in septic mice compared to controls. Isoflurane, known for its potential as a sedation drug in bedside applications, lacks clarity regarding its impact on the microcirculation system. The hypothesis was that propofol would exert a more pronounced influence on the microvascular flow index, particularly amplified in septic conditions. MATERIAL AND METHODS: Randomized study was conducted from December 2020 to October 2021 involved 60 BALB/c mice, with 52 mice analyzed. Dorsal skinfold chambers were implanted, followed by intraperitoneal injections of either sterile 0.9 % saline or lipopolysaccharide for the control and sepsis groups, respectively. Both groups received propofol or isoflurane treatment for 120 min. Microcirculatory parameters were obtained via incident dark-field microscopy videos, along with the mean blood pressure and heart rate at three time points: before sedation (T0), 30 min after sedation (T30), and 120 min after sedation (T120). Endothelial glycocalyx thickness and syndecan-1 concentration were also analyzed. RESULTS: In healthy controls, both anesthetics reduced blood pressure. However, propofol maintained microvascular flow, differing significantly from isoflurane at T120 (propofol, 2.8 ± 0.3 vs. isoflurane, 1.6 ± 0.9; P < 0.001). In the sepsis group, a similar pattern occurred at T120 without statistical significance (propofol, 1.8 ± 1.1 vs. isoflurane, 1.2 ± 0.7; P = 0.023). Syndecan-1 levels did not differ between agents, but glycocalyx thickness index was significantly lower in the isoflurane-sepsis group than propofol (P = 0.001). CONCLUSIONS: Propofol potentially offers protective action against microvascular flow deterioration compared to isoflurane, observed in control mice. Furthermore, a lower degree of sepsis-induced glycocalyx degradation was evident with propofol compared to isoflurane.


Asunto(s)
Anestésicos por Inhalación , Isoflurano , Propofol , Sepsis , Animales , Ratones , Propofol/farmacología , Isoflurano/farmacología , Microcirculación , Sindecano-1 , Anestésicos por Inhalación/farmacología , Sepsis/tratamiento farmacológico , Anestésicos Intravenosos/farmacología
7.
Med Sci Monit ; 30: e943036, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38308426

RESUMEN

BACKGROUND This subgroup analysis of prospective observational research, involving 71 participants, compared the effects of anesthesia on microvascular reactivity in obese vs lean individuals using near-infrared spectroscopy and vascular occlusion tests. The correlation between the body mass index (BMI) and microvascular reactivity under general anesthesia was also investigated. MATERIAL AND METHODS This study enrolled adult patients classified as American Society of Anesthesiologists physical status I or II, undergoing elective surgery under general anesthesia. The microcirculatory variables measured before (Tpre) and 30 min following the induction of anesthesia (Tpost) were as follows: baseline tissue oxygen saturation (StO2), occlusion slope (∇occl), and recovery slope (∇recov). The patients were grouped according to their BMI (lean [BMI <25 kg/m²] vs obese [BMI ≥25 kg/m²]). Data are presented as medians and interquartile ranges. RESULTS There were 43 patients in the lean group and 28 in the obese group. At Tpre, baseline StO2, ∇occl, and ∇recov were not different between the 2 groups (P=0.860, 0.659, and 0.518, respectively). At Tpost, the baseline StO2 and ∇occl were not different between the 2 groups (P=0.343 and 0.791); however, the ∇recov was lower in the obese group than in the lean group (3.245 [2.737, 3.977] vs 4.131 [3.491, 4.843], P=0.003). At Tpost, BMI showed a moderate correlation with ∇recov (correlation coefficient: -0.319, P=0.007). CONCLUSIONS In obese patients, capillary recruitment capacity during general anesthesia is compromised compared to lean patients.


Asunto(s)
Obesidad , Enfermedades Vasculares , Adulto , Humanos , Anestesia General , Índice de Masa Corporal , Capilares , Microcirculación , Estudios Observacionales como Asunto
8.
Biotechnol Lett ; 46(4): 521-530, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38872071

RESUMEN

Blood coagulation mediated by pig tissue factor (TF), which is expressed in pig tissues, causes an instant blood-mediated inflammatory reaction during pig-to-human xenotransplantation. Previously, we generated a soluble pig tissue factor pathway inhibitor α fusion immunoglobulin (TFPI-Ig) which inhibits pig TF activity more efficiently than human TFPI-Ig in human plasma. In this study, we generated several pig TFPI-Ig mutants and tested the efficacy of these mutants in preventing pig-to-human xenogeneic blood coagulation. Structurally important amino acid residues of pig TFPI-Ig were changed into different residues by site-directed mutagenesis. Subsequently, a retroviral vector encoding each cDNA of several pig TFPI-Ig mutants was cloned and transduced into CHO-K1 cells. After establishing stable cell lines expressing each of the pig TFPI-Ig mutants, soluble proteins were produced and purified for evaluating their inhibitory effects on pig TF-mediated blood coagulation in human plasma. The replacement of K36 and K257 with R36 and H257, respectively, in pig TFPI-Ig more efficiently blocked pig TF activity in human plasma when compared with the wild-type pig TFPI-Ig. These results may provide additional information to understand the structure of pig TFPIα, and an improved pig TFPI-Ig variant that more efficiently blocks pig TF-mediated blood coagulation during pig-to-human xenotransplantation.


Asunto(s)
Coagulación Sanguínea , Lipoproteínas , Trasplante Heterólogo , Animales , Humanos , Porcinos , Lipoproteínas/genética , Lipoproteínas/metabolismo , Coagulación Sanguínea/genética , Células CHO , Cricetulus , Tromboplastina/genética , Tromboplastina/metabolismo , Mutagénesis Sitio-Dirigida , Análisis Mutacional de ADN
9.
Orthod Craniofac Res ; 27(2): 303-312, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37955169

RESUMEN

OBJECTIVE: To compare changes in the maxillary posterior structure as seen in cone-beam computed tomography (CBCT) images resulting from facemask therapy using skeletal (miniplate/FM) anchorage versus tooth-borne anchorage (RME/FM). MATERIALS AND METHODS: A retrospective study was conducted on 20 patients divided into the miniplate/FM group (nine patients aged 9.5 ± 1.4 years) and the RME/FM group (11 patients aged 9.2 ± 1.4 years). CBCT images before and after facemask therapy were evaluated to assess changes in the maxillary posterior structure. RESULTS: The miniplate/FM group had greater advancement of the maxilla and midface compared to the RME/FM group (p < .05). Specifically, there was about three times more advancement of the pterygomaxillary suture in the miniplate/FM group than in the RME/FM group (p < .05). Moreover, the advancement of the pterygomaxillary suture was about half the advancement of A point in the miniplate/FM group, while only about 25% in the RME/FM group. Finally, the miniplate/FM group showed an increase in the transverse dimension of the posterior and superior parts of the maxilla (p < .05). CONCLUSION: There was greater forward movement of the pterygomaxillary suture with facemask therapy using the skeletal anchorage compared to tooth-borne anchorage, leading to a more significant advancement of the maxilla and midface.


Asunto(s)
Maloclusión de Angle Clase III , Humanos , Maloclusión de Angle Clase III/terapia , Estudios Retrospectivos , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Máscaras , Técnica de Expansión Palatina , Aparatos de Tracción Extraoral , Cefalometría/métodos
10.
Plant Foods Hum Nutr ; 79(2): 482-488, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38748356

RESUMEN

Hypertension remains a significant global health concern, contributing significantly to cardiovascular diseases and mortality rates. The inhibition of angiotensin-converting enzyme (ACE) plays a crucial role in alleviating high blood pressure. We investigated the potential of finger millets (Eleusine coracana) as a natural remedy for hypertension by isolating and characterizing its ACE-inhibitory compound. First, we evaluated the ACE-inhibitory activity of the finger millet ethanol extract and subsequently proceeded with solvent fractionation. Among the solvent fractions, the ethyl acetate fraction exhibited the highest ACE inhibitory activity and was further fractionated. Using preparative high-performance liquid chromatography, the ethyl acetate fraction was separated into four subfractions, with fraction 2 (F2) exhibiting the highest ACE inhibitory activity. Subsequent 1 H-nuclear magnetic resonance (NMR) and 13 C-NMR analyses confirmed that the isolated compound from F2 was catechin. Furthermore, molecular docking studies indicated that catechin has the potential to act as an ACE inhibitor. These findings suggest that finger millets, particularly as a source of catechin, have the potential to be used as a natural antihypertensive.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Antihipertensivos , Eleusine , Simulación del Acoplamiento Molecular , Extractos Vegetales , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/química , Eleusine/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antihipertensivos/farmacología , Antihipertensivos/química , Cromatografía Líquida de Alta Presión , Peptidil-Dipeptidasa A/metabolismo , Hipertensión/tratamiento farmacológico , Espectroscopía de Resonancia Magnética
11.
Clin Proteomics ; 20(1): 45, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37875819

RESUMEN

Glioblastoma is one of the most malignant primary brain cancer. Despite surgical resection with modern technology followed by chemo-radiation therapy with temozolomide, resistance to the treatment and recurrence is common due to its aggressive and infiltrating nature of the tumor with high proliferation index. The median survival time of the patients with glioblastomas is less than 15 months. Till now there has been no report of molecular target specific for glioblastomas. Early diagnosis and development of molecular target specific for glioblastomas are essential for longer survival of the patients with glioblastomas. Development of biomarkers specific for glioblastomas is most important for early diagnosis, estimation of the prognosis, and molecular target therapy of glioblastomas. To that end, in this study, we have conducted a comprehensive proteome study using primary cells and tissues from patients with glioblastoma. In the discovery stage, we have identified 7429 glioblastoma-specific proteins, where 476 proteins were quantitated using Tandem Mass Tag (TMT) method; 228 and 248 proteins showed up and down-regulated pattern, respectively. In the validation stage (20 selected target proteins), we developed quantitative targeted method (MRM: Multiple reaction monitoring) using stable isotope standards (SIS) peptide. In this study, five proteins (CCT3, PCMT1, TKT, TOMM34, UBA1) showed the significantly different protein levels (t-test: p value ≤ 0.05, AUC ≥ 0.7) between control and cancer groups and the result of multiplex assay using logistic regression showed the 5-marker panel showed better sensitivity (0.80 and 0.90), specificity (0.92 and 1.00), error rate (10 and 2%), and AUC value (0.94 and 0.98) than the best single marker (TOMM34) in primary cells and tissues, respectively. Although we acknowledge that the model requires further validation in a large sample size, the 5 protein marker panel can be used as baseline data for the discovery of novel biomarkers of the glioblastoma.

12.
Eur J Nucl Med Mol Imaging ; 50(3): 765-783, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36372804

RESUMEN

Alzheimer's disease (AD) is the most common dementia worldwide. The exact etiology of AD is unclear as yet, and no effective treatments are currently available, making AD a tremendous burden posed on the whole society. As AD is a multifaceted and heterogeneous disease, and most biomarkers are dynamic in the course of AD, a range of biomarkers should be established to evaluate the severity and prognosis. Positron emission tomography (PET) offers a great opportunity to visualize AD from diverse perspectives by using radiolabeled agents involved in various pathophysiological processes; PET imaging technique helps to explore the pathomechanisms of AD comprehensively and find out the most appropriate biomarker in each AD phase, leading to a better evaluation of the disease. In this review, we discuss the application of PET in the course of AD and summarized radiolabeled compounds with favorable imaging characteristics.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Imagen Molecular , Biomarcadores , Péptidos beta-Amiloides
13.
Theor Appl Genet ; 136(7): 166, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37393202

RESUMEN

KEY MESSAGE: One major quantitative trait loci and candidate gene for salt tolerance were identified on chromosome 3 from a new soybean mutant derived from gamma-ray irradiation, which will provide a new genetic resource for improving soybean salt tolerance. Soil salinity is a worldwide problem that reduces crop yields, but the development of salt-tolerant crops can help overcome this challenge. This study was conducted with the purpose of evaluating the morpho-physiological and genetic characteristics of a new salt-tolerant mutant KA-1285 developed using gamma-ray irradiation in soybean (Glycine max L.). The morphological and physiological responses of KA-1285 were compared with salt-sensitive and salt-tolerant genotypes after treatment with 150 mM NaCl for two weeks. In addition, a major salt tolerance quantitative trait locus (QTL) was identified on chromosome 3 in this study using the Daepung X KA-1285 169 F2:3 population, and a specific deletion was identified in Glyma03g171600 (Wm82.a2.v1) near the QTL region based on re-sequencing analysis. A kompetitive allele-specific PCR (KASP) marker was developed based on the deletion of Glyma03g171600 which distinguished the wild-type and mutant alleles. Through the analysis of gene expression patterns, it was confirmed that Glyma03g171700 (Wm82.a2.v1) is a major gene that controls salt tolerance functions in Glyma03g32900 (Wm82.a1.v1). These results suggest that the gamma-ray-induced mutant KA-1285 has the potential to be employed for the development of a salt-tolerant cultivar and provide useful information for genetic research related to salt tolerance in soybeans.


Asunto(s)
Glycine max , Glycine max/genética , Alelos , Rayos gamma , Genotipo , Reacción en Cadena de la Polimerasa
14.
J Biomed Sci ; 30(1): 66, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37568205

RESUMEN

BACKGROUND: Parkinson's disease (PD) is the second most frequent age-related neurodegenerative disorder and is characterized by the loss of dopaminergic neurons. Both environmental and genetic aspects are involved in the pathogenesis of PD. Osmotin is a structural and functional homolog of adiponectin, which regulates the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) via adiponectin receptor 1 (AdipoR1), thus attenuating PD-associated pathology. Therefore, the current study investigated the neuroprotective effects of osmotin using in vitro and in vivo models of PD. METHODS: The study used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced and neuron-specific enolase promoter human alpha-synuclein (NSE-hαSyn) transgenic mouse models and 1-methyl-4-phenylpyridinium (MPP+)- or alpha-synuclein A53T-treated cell models. MPTP was injected at a dose of 30 mg/kg/day for five days, and osmotin was injected twice a week at a dose of 15 mg/kg for five weeks. We performed behavioral tests and analyzed the biochemical and molecular changes in the substantia nigra pars compacta (SNpc) and the striatum. RESULTS: Based on our study, osmotin mitigated MPTP- and α-synuclein-induced motor dysfunction by upregulating the nuclear receptor-related 1 protein (Nurr1) transcription factor and its downstream markers tyrosine hydroxylase (TH), dopamine transporter (DAT), and vesicular monoamine transporter 2 (VMAT2). From a pathological perspective, osmotin ameliorated neuronal cell death and neuroinflammation by regulating the mitogen-activated protein kinase (MAPK) signaling pathway. Additionally, osmotin alleviated the accumulation of α-synuclein by promoting the AMPK/mammalian target of rapamycin (mTOR) autophagy signaling pathway. Finally, in nonmotor symptoms of PD, such as cognitive deficits, osmotin restored synaptic deficits, thereby improving cognitive impairment in MPTP- and α-synuclein-induced mice. CONCLUSIONS: Therefore, our findings indicated that osmotin significantly rescued MPTP/α-synuclein-mediated PD neuropathology. Altogether, these results suggest that osmotin has potential neuroprotective effects in PD neuropathology and may provide opportunities to develop novel therapeutic interventions for the treatment of PD.


Asunto(s)
Fármacos Neuroprotectores , Enfermedad de Parkinson , Humanos , Ratones , Animales , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , alfa-Sinucleína/farmacología , Fármacos Neuroprotectores/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Sustancia Negra/metabolismo , Transducción de Señal , Neuronas Dopaminérgicas/metabolismo , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Serina-Treonina Quinasas TOR/farmacología , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Mamíferos
15.
Bioorg Chem ; 134: 106466, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36934691

RESUMEN

Actinidia polygama has been used as a traditional medicine for treating various diseases. In the present study, 13 compounds, including three new monoterpenoids (1-3), were isolated from the leaves of A. polygama to investigate the bioactive constituents of the plant. The structures were characterized by analyzing spectroscopic and chiroptical data. These compounds were preliminarily screened for their ability to increase insulin secretion levels after glucose stimulation. Of these, 3-O-coumaroylmaslinic acid (4) and jacoumaric acid (5) showed activity. In further biological studies, these compounds exhibited increased glucose-stimulated insulin secretion (GSIS) activity without cytotoxicity in rat INS-1 pancreatic ß-cells as well as α-glucosidase inhibitory activity. Furthermore, both compounds increased insulin receptor substrate-2 (IRS-2), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), pancreatic and duodenal homeobox-1 (PDX-1), and peroxisome proliferator-activated receptor-γ (PPAR-γ) expression. Hence, these compounds may be developed as potential antidiabetic agents.


Asunto(s)
Actinidia , alfa-Glucosidasas , Ratas , Animales , Secreción de Insulina , alfa-Glucosidasas/metabolismo , Actinidia/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Glucosa/metabolismo , Insulina/metabolismo
16.
Environ Res ; 221: 115305, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36642120

RESUMEN

Phenols are significant environmental endocrine disruptors that can have adverse health effects on exposed individuals. Correlating phenol exposure to potential health implications requires the development of a comprehensive and sensitive analytical method capable of analyzing multiple phenols in a single sample preparation and analytical run. Currently, no such method is available for multiple classes of phenols due to electrospray ionization (ESI) limitations in concurrent ionization and lack of sensitivity to certain phenols, particularly alkylphenols. In this study, we investigated the influence of mobile phase compositions in ESI on concurrent ionization and analytical sensitivity of liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) during the analysis of multiple classes of phenols, and we propose a comprehensive and sensitive analytical method for various classes of phenols (i.e., bisphenols, parabens, benzophenones, chlorophenols, and alkylphenols). The proposed method was affected by 0.5 mM ammonium fluoride under methanol conditions. It enabled the concurrent ionization of all the phenols and significantly improved the analytical sensitivity for bisphenols and alkylphenols, which typically have poor ionization efficiency. This method, combined with a "dilute and shoot" approach, allowed us to simultaneously quantify 38 phenols with good chromatographic behavior and sensitivity. Furthermore, the method was successfully applied to the analysis of 61 urine samples collected from aquatic (swimming) and land (indoor volleyball and outdoor football) athletes.


Asunto(s)
Clorofenoles , Humanos , Espectrometría de Masas en Tándem/métodos , Parabenos/análisis , Benzofenonas/análisis , Cromatografía Liquida/métodos , Fenoles/orina , Espectrometría de Masa por Ionización de Electrospray/métodos
17.
BMC Public Health ; 23(1): 1226, 2023 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-37355587

RESUMEN

BACKGROUND: The COVID-19 pandemic has highlighted the need for global unity and timely access to healthcare for all including multilingual and intercultural societies. This study aimed to identify barriers to healthcare access due to the COVID-19 crisis among Nepalese migrants in Japan and explore ways to counter these barriers, both in routine and crisis situations. METHODS: This study used an exploratory sequential mixed-methods study design. The researchers conducted 11 focus group discussions including 89 participants and an online survey involving 937 respondents. The integration of focus group discussions and logistic regression analysis from the survey was reported via a 'joint display'. RESULTS: Twenty-six themes on barriers to and six on facilitators of healthcare accessibility were identified by the focus group discussions among which 17 barriers like lack of knowledge of health insurance, language barriers, lack of hotline services, unawareness of available services, fear of discrimination etc. had significant association in our logistic regression analysis after adjusting for all confounders. Similarly, the only facilitator that had a significant impact, according to the multivariable logistic regression analysis, was receiving health information from Nepali healthcare professionals (OR = 1.36, 95% CI = (1.01 - 1.82), p-value < 0.05). CONCLUSION: The study suggests the need for a crisis information hub which could be coordinated by the Nepal embassy or concerned authorities, flexible policies for active deployment of Nepalese health workers and volunteers, accessible hotlines in the Nepali language, and incorporation of Nepali telehealth services in Japan.


Asunto(s)
COVID-19 , Migrantes , Humanos , COVID-19/epidemiología , Nepal/epidemiología , Pandemias , Japón/epidemiología , Accesibilidad a los Servicios de Salud
18.
BMC Health Serv Res ; 23(1): 1388, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-38082399

RESUMEN

BACKGROUND: We determined the cost-effectiveness of the anti-vascular endothelial growth factor (VEGF) intravitreal injection versus panretinal photocoagulation (PRP) for patients with proliferative diabetic retinopathy (PDR) in South Korea. METHODS: We simulated four treatment strategies using PRP and the anti-VEGF injection by constructing a Markov model for a hypothetical cohort of 50-year-old PDR patients: (1) PRP only; (2) anti-VEGF injection only; (3) PRP first; and (4) anti-VEGF injection first. RESULTS: In this cost-effectiveness analysis, compared with only-PRP, the incremental cost-effectiveness ratio was $95,456 per quality-adjusted life-year (QALY) for PRP first, $34,375 per QALY for anti-VEGF injection first, and $33,405 per QALY for anti-VEGF injection only from a healthcare perspective. From the societal and payer perspective, strategy (2) was more cost-saving and effective than (1). In the probabilistic sensitivity analysis, only-PRP was cost-effective up to the willingness-to-pay (WTP) of about $42,000, while anti-VEGF injection only was cost-effective from a healthcare perspective. From the societal and payer perspectives, regardless of the value of WTP, anti-VEGF injection only was the most cost-effective strategy. CONCLUSION: In our study, the anti-VEGF injection for PDR was cost-effective from the payer and societal perspectives.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , Humanos , Persona de Mediana Edad , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/cirugía , Ranibizumab/uso terapéutico , Análisis Costo-Beneficio , Inhibidores de la Angiogénesis/uso terapéutico , Factores de Crecimiento Endotelial/uso terapéutico , Inyecciones Intravítreas , Análisis de Costo-Efectividad , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , Coagulación con Láser , Diabetes Mellitus/terapia
19.
J Korean Med Sci ; 38(23): e195, 2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-37309700

RESUMEN

BACKGROUND: In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration. METHODS: The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations. RESULTS: An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3-4 months. CONCLUSION: We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media. Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics.


Asunto(s)
COVID-19 , Niño , Humanos , Adenosina-5'-(N-etilcarboxamida) , República de Corea , SARS-CoV-2 , Guías de Práctica Clínica como Asunto
20.
Nano Lett ; 22(18): 7477-7483, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36069205

RESUMEN

Solid-state batteries (SSBs) have received attention as a next-generation energy storage technology due to their potential to superior deliver energy density and safety compared to commercial Li-ion batteries. One of the main challenges limiting their practical implementation is the rapid capacity decay caused by the loss of contact between the cathode active material and the solid electrolyte upon cycling. Here, we use the promising high-voltage, low-cost LiNi0.5Mn1.5O4 (LNMO) as a model system to demonstrate the importance of the cathode microstructure in SSBs. We design Al2O3-coated LNMO particles with a hollow microstructure aimed at suppressing electrolyte decomposition, minimizing volume change during cycling, and shortening the Li diffusion pathway to achieve maximum cathode utilization. When cycled with a Li6PS5Cl solid electrolyte, we demonstrate a capacity retention above 70% after 100 cycles, with an active material loading of 27 mg cm-2 (2.2 mAh cm-2) at a current density of 0.8 mA cm-2.

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