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Reevaluating the composition of the double metal cyanide catalyst (DMC) as a salt of (NC)6Co3- anions with 1:1 Zn2+/(X)Zn+ cations (X = Cl, RO, AcO), we prepared a series of well-defined DMCs, [ClZn+][Zn2+][(NC)6Co3-][ROH], [(RO)Zn+][Zn2+][(NC)6Co3-], [(AcO)Zn+][Zn2+][(NC)6Co3-], [(RO)Zn+]p[ClZn+](1-p)[Zn2+][(NC)6Co3-], [(AcO)Zn+]p[(tBuO)Zn+]q[Zn2+][(NC)6Co3-], and [(AcO)Zn+]p[(tBuO)Zn+]q[ClZn+]r[Zn2+][(NC)6Co3-]. The structure of [(MeOC3H6O)Zn+][Zn2+][(NC)6Co3-] was precisely determined at the atomic level through Rietveld refinement of the synchrotron X-ray powder diffraction data. By evaluating the catalyst's performance in both propylene oxide (PO) polymerization and PO/CO2 copolymerization, a correlation between structure and performance was established on various aspects including activity, dispersity, unsaturation level, and carbonate fraction in the resulting polyols. Ultimately, our study identified highly efficient catalysts that outperformed the state-of-the-art benchmark DMC not only in PO polymerization [DMC-(OAc/OtBu/Cl)(0.59/0.38/0.15)] but also in PO/CO2 copolymerization [DMC-(OAc/OtBu)(0.95/0.08)].
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PURPOSE: Local steroid injection is an effective treatment modality for carpal tunnel syndrome. This study aimed to investigate the success rate of ultrasonography-guided local steroid injection and determine the prognostic value of the cross-sectional area (CSA) of the median nerve for steroid injection. METHODS: We retrospectively evaluated 40 patients with carpal tunnel syndrome whose median nerve CSA was >15 mm2 (large-CSA group; n = 16) or ≤15 mm2 (small-CSA group; n = 24). The CSA was measured using ultrasonography, and all the patients were treated with ultrasonography-guided corticosteroid injection. Demographic characteristics, symptoms, initial QuickDASH score, Boston Carpal Tunnel Questionnaires, and results of the nerve conduction study were assessed at baseline. Treatment success was defined in this study as the absence of symptom recurrence within the entire follow-up period. RESULTS: The treatment success rate was 45% (n = 18) after an average follow-up of 16 months. Overall, 11 patients (28%) underwent carpal tunnel release on an average of 11 months after steroid injection. The large-CSA group showed a significantly worse grade of electrodiagnostic testing at baseline than did the small-CSA group; however, there was no significant difference in final Boston Carpal Tunnel Questionnaires symptom score (1.7 vs 1.8, respectively) and the rate of continued treatment success at the last follow-up (42% vs 50%, respectively). The proportions of patients who required carpal tunnel decompression were 29% and 25% in the small-CSA and large-CSA groups, respectively. CONCLUSIONS: Local steroid injection for carpal tunnel syndrome has an overall success rate of 45% after a mean follow-up of 16 months. Preinjection CSA was not associated with whether the steroid injection was considered successful. This indicates that increased median nerve CSA does not preclude the possibility of symptomatic relief after a local steroid injection. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
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Síndrome del Túnel Carpiano , Nervio Mediano , Humanos , Nervio Mediano/diagnóstico por imagen , Nervio Mediano/cirugía , Síndrome del Túnel Carpiano/diagnóstico por imagen , Síndrome del Túnel Carpiano/tratamiento farmacológico , Síndrome del Túnel Carpiano/cirugía , Pronóstico , Estudios Retrospectivos , Ultrasonografía , Esteroides/uso terapéuticoRESUMEN
Melanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use.
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Melaninas , alfa-MSH , Melaninas/metabolismo , alfa-MSH/metabolismo , Monofenol Monooxigenasa/metabolismo , Factor de Transcripción Asociado a Microftalmía/genética , Factor de Transcripción Asociado a Microftalmía/metabolismo , Línea Celular TumoralRESUMEN
The efficiency of plasma surface modifications depends on the operating conditions. This study investigated the effect of chamber pressure and plasma exposure time on the surface properties of 3Y-TZP with N2/Ar gas. Plate-shaped zirconia specimens were randomly divided into two categories: vacuum plasma and atmospheric plasma. Each group was subdivided into five subgroups according to the treatment time: 1, 5, 10, 15, and 20 min. Following the plasma treatments, we characterized the surface properties, including wettability, chemical composition, crystal structure, surface morphology, and zeta potential. These were analyzed through various techniques, such as contact angle measurement, XPS, XRD, SEM, FIB, CLSM, and electrokinetic measurements. The atmospheric plasma treatments increased zirconia's electron donation (γ-) capacity, while the vacuum plasma treatments decreased γ- parameter with increasing times. The highest concentration of the basic hydroxyl OH(b) groups was identified after a 5 min exposure to atmospheric plasmas. With longer exposure times, the vacuum plasmas induce electrical damage. Both plasma systems increased the zeta potential of 3Y-TZP, showing positive values in a vacuum. In the atmosphere, the zeta potential rapidly increased after 1 min. Atmospheric plasma treatments would be beneficial for the adsorption of oxygen and nitrogen from ambient air and the generation of various active species on the zirconia surface.
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Presión Atmosférica , Circonio , Cerámica/química , Ensayo de Materiales , Propiedades de Superficie , Humectabilidad , Itrio , Circonio/químicaRESUMEN
INTRODUCTION: A one-way valve lesion plays an important role in the formation of Baker's cysts and serves as an important landmark for accessing these cysts during arthroscopic surgery. This study aimed to investigate the incidence of one-way valve lesions and their effect on clinical outcomes in patients who underwent arthroscopic cystectomy for Baker's cysts. MATERIALS AND METHODS: Patients who underwent arthroscopic cystectomy for Baker's cysts between June 2005 and November 2017 were retrospectively reviewed. Patient demographic characteristics, radiologic/arthroscopic findings (presence of one-way valve lesions, concurrent chondral and meniscal lesions, and cyst wall thickness), and clinical outcomes (clinical recurrence rate, Lysholm score, and complications) at the 2-year follow-up were evaluated. Subgroup analysis was performed to compare clinical outcomes between patients with and without one-way valve lesions. RESULTS: Thirty patients (mean age, 57.4 ± 9.4 years) were included in this study. One-way valve lesions were surgically documented in 11 patients (36.7%). Ten patients (33.3%) had chondral lesions with an International Cartilage Repair Society grade ≥ 3, and 23 patients (76.7%) had concurrent chondral and meniscal lesions. At the 2-year follow-up, none of the patients had experienced clinical recurrence; the mean Lysholm score was 76.3 ± 17.5 (48-100). Three patients reported persistent pain, while two reported numbness or paresthesia. Subgroup analysis showed no significant differences in clinical recurrence rates, Lysholm scores, and complication rates between the groups. CONCLUSIONS: The incidence of one-way valve lesions during arthroscopic cystectomy for Baker's cysts was lower than that previously reported. Arthroscopic cystectomy showed good clinical results in patients with and without these lesions.
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Cistectomía , Quiste Poplíteo , Humanos , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Incidencia , Cistectomía/efectos adversos , Quiste Poplíteo/epidemiología , Quiste Poplíteo/cirugía , Quiste Poplíteo/complicaciones , Artroscopía/métodosRESUMEN
OBJECTIVE: This study aimed to pilot PAX ("Play, Act & Interact"), an activity-based emotional support intervention for caregivers of child with cancer, which focuses on addressing their psychological distress and post-traumatic stress symptoms (PTSSs). METHOD: Sixteen mothers whose children were child with cancer participated in this 4-week intervention. Their children (n = 16; 14 males; median age at diagnosis = 10.3 years; the median amount of time from diagnosis = 9 months) were at different treatment stages for a range of different diagnoses. Caregivers completed self-report instruments assessing their psychological distress including PTSSs and family functioning before and after the intervention and a brief open-response exit survey. Paired sample t-tests were computed to compare the pre-and post-intervention scores. RESULTS: The Post-traumatic Stress Disorder Checklist scores significantly decreased from pre- (M = 37.00, SD = 14.75) to post-intervention (M = 32.56, SD = 15.52), t(15) = 4.25, p < .001. There was also a significant difference between pre- (M = 33.5, SD = 3.18) and post-intervention (M = 35.7, SD = 3.14) scores on the Family Adherence subscale of the Family Adaptability and Cohesion Evaluation Scales III, t(15) = -2.58, p = .02. CONCLUSIONS: PAX was a promising intervention for supporting caregivers' PTSSs and family adaptability. Future studies investigating the long-term effects and replicating the current study with more participants and a control group are needed.
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Cuidadores/psicología , Neoplasias , Apoyo Social , Estrés Psicológico/terapia , Niño , Femenino , Humanos , Masculino , Madres , Neoplasias/terapia , Encuestas y CuestionariosRESUMEN
Plasma surface treatment can be an attractive strategy for modifying the chemically inert nature of zirconia to improve its clinical performance. This study aimed to clarify the effect of plasma gas compositions on the physicochemical surface modifications of 3 mol% yttria-stabilized zirconia (3Y-TZP). The cold, atmospheric plasma discharges were carried out by using four different plasma gases, which are He/O2, N2/Ar, N2, and Ar from an application distance of 10 mm for 60 s. Static contact angles were measured to define the surface free energy. Changes in elemental composition, surface crystallinity, and surface topography were assessed with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM), respectively. A significant decrease in water contact angle was observed in all plasma groups with the lowest value of 69° in the N2/Ar group. CLSM and SEM investigations exhibited no morphological changes in all plasma groups. XPS revealed that a reduction in the surface C content along with an increase in O content was pronounced in the case of N2/Ar compared to others, which was responsible for high hydrophilicity of the surface. XRD showed that the changes in crystallite size and microstrain due to oxygen atom displacements were observed in the N2/Ar group. The N2/Ar plasma treatment may contribute to enhancing the bioactivity as well as the bonding performance of 3Y-TZP by controlling the plasma-generated nitrogen functionalities.
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Gases em Plasma , Itrio , Cerámica/química , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Propiedades de Superficie , Difracción de Rayos X , Itrio/química , Circonio/químicaRESUMEN
Funding information from the original version of this article was incomplete. Complete information is presented here.
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PURPOSE: We developed a new method to directly calculate Centiloid (CL) units of 18F-florbetaben (FBB) and 18F-flutemetamol (FMM) without conversion to the PiB standardized uptake value ratio (SUVR). METHODS: Paired FBB and FMM PET scans were obtained from 20 Alzheimer's disease-related cognitive impairment patients, 16 old controls, and 20 young controls. We investigated the correlations between the FBB and FMM CL units using the direct comparison of FBB-FMM CL (dcCL) method and the standard CL method and compare differences in FBB and FMM CL units between dcCL method and the standard method. RESULTS: Following the conversion of FBB or FMM SUVRs into CL units, a direct relationship was formed between the FBB or FMM SUVRs and the CL units using dcCL method (FBB dcCL = 151.42 × FBB dcSUVR - 142.24 and FMM dcCL = 148.52 × FMM dcSUVR - 137.09). The FBB and FMM CL units were highly correlated in both our method (R2 = 0.97, FMM dcCL = 0.97 × FBB dcCL + 1.64) and the standard method (R2 = 0.97, FMM CLstandard = 0.79 × FBB CLstandard + 1.36). However, the CL variations between FBB and FMM were smaller when calculated by dcCL method (6.15) than when calculated by the previous method (10.22; P = 0.01). CONCLUSIONS: Our findings suggest that our direct comparison of FBB-FMM method, rather than the standard method, is a reasonable way to convert FBB or FMM SUVRs into CL units, at least in environments where FBB or FMM ligands are used frequently.
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Enfermedad de Alzheimer , Estilbenos , Compuestos de Anilina , Benzotiazoles , Encéfalo , Humanos , Tomografía de Emisión de PositronesRESUMEN
OBJECTIVE: To apply an AT (Aß/tau) classification system to subcortical vascular cognitive impairment (SVCI) patients following recently developed biomarker-based criteria of Alzheimer's disease (AD), and to investigate its clinical significance. METHODS: We recruited 60 SVCI patients who underwent the neuropsychological tests, brain MRI, and 18F-florbetaben and 18F-AV1451 PET at baseline. As a control group, we further recruited 27 patients with AD cognitive impairment (ADCI; eight Aß PET-positive AD dementia and 19 amnestic mild cognitive impairment). ADCI and SVCI patients were classified as having normal or abnormal Aß (A-/A+) and tau (T-/T+) based on PET results. Across the three SVCI groups (A-, A+T-, and A+T+SVCI), we compared longitudinal changes in cognition, hippocampal volume (HV), and cortical thickness using linear mixed models. RESULTS: Among SVCI patients, 33 (55%), 20 (33.3%), and seven (11.7%) patients were A-, A+T-, and A+T+, respectively. The frequency of T+ was lower in A+SVCI (7/27, 25.9%) than in A+ADCI (14/20, 70.0%, p = 0.003) which suggested that cerebral small vessel disease affected cognitive impairments independently of A+. A+T-SVCI had steeper cognitive decline than A-SVCI. A+T+SVCI also showed steeper cognitive decline than A+T-SVCI. Also, A+T-SVCI had steeper decrease in HV than A-SVCI, while cortical thinning did not differ between the two groups. A+T+SVCI had greater global cortical thinning compared with A+T-SVCI, while declines in HV did not differ between the two groups. CONCLUSION: This study showed that the AT system successfully characterized SVCI patients, suggesting that the AT system may be usefully applied in a research framework for clinically diagnosed SVCI.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad de Alzheimer/diagnóstico por imagen , Amiloide , Péptidos beta-Amiloides , Disfunción Cognitiva/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Proteínas tauRESUMEN
BACKGROUND: Several conservative treatment methods, from intrinsic muscle exercises to orthoses, including insoles or specially designed shoes, have been introduced for pediatric flexible flat foot (PFFF). However, the structural effects of a long-term use of medial arch support insole remain unclear because the normal physiological maturation of the medial longitudinal arch cannot be ruled out. METHODS: From January 2005 to June 2015, 18 patients (34 feet) in group 1 (continuously insole applied group) and 13 patients (26 feet) in group 2 (untreated group) were enrolled. Medial arch support insole was applied from the age 10-11years to radiographic physeal closure. RESULTS: In group 1, talonavicular coverage angle, lateral talo-1st metatarsal angle, calcaneal pitch angle and medial cuneiform height were significantly changed at final follow-up, although all values were still within the abnormal range. Further, no significant differences were found in any of the increments of the radiographic parameters between group 1 and 2. CONCLUSIONS: Radiographic improvements were found in both of medial arch support insole treated or untreated group despite all radiographic values were still within the abnormal range. It was meaningful that the PFFF could be improved somewhat until the physes were closed. And the hindfoot alignment remained unchanged regardless of medial arch support insole application.
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Pie Plano/diagnóstico , Radiografía/métodos , Zapatos , Niño , Femenino , Pie Plano/rehabilitación , Estudios de Seguimiento , Humanos , Masculino , Estudios Prospectivos , Factores de TiempoRESUMEN
PURPOSE: We investigated the frequency and clinical significance of amyloid ß (Aß) positivity on PET in patients with cerebral amyloid angiopathy (CAA). METHODS: We recruited 65 patients who met the modified Boston criteria for probable CAA. All underwent amyloid PET, MRI, APOE genotyping and neuropsychological testing, and we obtained information on MRI markers of CAA and ischemic cerebral small-vessel disease (CSVD). We investigated the CAA/ischemic CSVD burden and APOE genotypes in relation to Aß positivity and investigated the effect of Aß positivity on longitudinal cognitive decline. RESULTS: Among the 65 CAA patients, 43 (66.2%) showed Aß PET positivity (Aß+). Patients with Aß+ CAA had more lobar microbleeds (median 9, interquartile range 2-41, vs. 3, 2-8; P = 0.045) and a higher frequency of cortical superficial siderosis (34.9% vs. 9.1%; P = 0.025), while patients with Aß- CAA had more lacunes (1, 0-2, vs. 0, 0-1; P = 0.029) and a higher frequency of severe white matter hyperintensities (45.5% vs. 20.9%; P = 0.040). The frequency of ε4 carriers was higher in Aß+ patients (57.1%) than in Aß- patients (18.2%; P = 0.003), while the frequency of ε2 carriers did not differ between the two groups. Finally, Aß positivity was associated with faster decline in multiple cognitive domains including language (P < 0.001), visuospatial function (P < 0.001), and verbal memory (P < 0.001) in linear mixed effects models. CONCLUSION: Our findings suggest that a significant proportion of patients with probable CAA in a memory clinic are Aß- on PET. Aß positivity in CAA patients is associated with a distinct pattern of CSVD biomarker expression, and a worse cognitive trajectory. Aß positivity has clinical relevance in CAA and might represent either advanced CAA or additional Alzheimer's disease neuropathological changes.
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Péptidos beta-Amiloides/genética , Apolipoproteínas E/genética , Angiopatía Amiloide Cerebral/diagnóstico por imagen , Trastornos del Conocimiento/diagnóstico por imagen , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Hemorragia Cerebral/diagnóstico por imagen , Cognición , Femenino , Genotipo , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estudios Prospectivos , Sustancia Blanca/diagnóstico por imagenRESUMEN
Self-emitting blue and red EuOX (X = F, Cl, Br, and I) were successfully synthesized and characterized. Far-infrared and Raman measurements revealed that the vibration modes prominently reflected the Eu-O and Eu-X bond characters of these materials. X-ray photoelectron spectroscopy (XPS) of the red-emitting EuOX compounds showed that Eu exclusively existed as Eu3+, while in the blue-emitting EuOX, a mixed Eu3+/Eu2+ state was observed. For the red-emitting EuOX (X = F, Cl, and Br), the maximum wavelengths of the charge-transfer (CT) bands were red-shifted: F â Cl â Br (282, 320, and 330 nm for F, Cl, and Br, respectively). Using one-electron spin-polarized band structure calculations, it was verified that the red-shift of the CT energy from F to Br in EuOX was mainly due to the relative positions of the halogen orbital energies being gradually increased, following the trend in their electronegativity. For the blue-emitting EuOX (X = Cl, Br, and I), the emission band maxima were red-shifted from Cl to I (409, 414, and 432 nm for Cl, Br, and I, respectively), which was quite opposite to the trend predicted based on the spectrochemical series in crystal field theory, which was in good agreement with the previous results of the calculated 5d â 4f transition energies of the Eu2+ activator based on the crystal field theory. Through photoluminescence, UV-visible absorbance, and XPS, it was elucidated that the red emission due to Eu3+ was strongly masked by the intensified blue emission associated with the small amount of Eu2+ in the blue-emitting EuOX (X = Cl, Br, and I). These materials may provide a platform for modeling new phosphors for application in solid-state lighting.
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PURPOSE: We estimated whether amyloid involvement in subcortical regions may predict cognitive impairment, and established an amyloid staging scheme based on degree of subcortical amyloid involvement. METHODS: Data from 240 cognitively normal older individuals, 393 participants with mild cognitive impairment, and 126 participants with Alzheimer disease were acquired at Alzheimer's Disease Neuroimaging Initiative sites. To assess subcortical involvement, we analyzed amyloid deposition in amygdala, putamen, and caudate nucleus. We staged participants into a 3-stage model based on cortical and subcortical amyloid involvement: 382 with no cortical or subcortical involvement as stage 0, 165 with cortical but no subcortical involvement as stage 1, and 203 with both cortical and subcortical involvement as stage 2. RESULTS: Amyloid accumulation was first observed in cortical regions and spread down to the putamen, caudate nucleus, and amygdala. In longitudinal analysis, changes in MMSE, ADAS-cog 13, FDG PET SUVR, and hippocampal volumes were steepest in stage 2 followed by stage 1 then stage 0 (p value <0.001). Stage 2 showed steeper changes in MMSE score (ß [SE] = -0.02 [0.004], p < 0.001), ADAS-cog 13 (0.05 [0.01], p < 0.001), FDG PET SUVR (-0.0008 [0.0003], p = 0.004), and hippocampal volumes (-4.46 [0.65], p < 0.001) compared to stage 1. CONCLUSIONS: We demonstrated a downward spreading pattern of amyloid, suggesting that amyloid accumulates first in neocortex followed by subcortical structures. Furthermore, our new finding suggested that an amyloid staging scheme based on subcortical involvement might reveal how differential regional accumulation of amyloid affects cognitive decline through functional and structural changes of the brain.
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Amiloide/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/metabolismo , Anciano , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Estudios de Casos y Controles , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/patología , Demencia/diagnóstico por imagen , Femenino , Fluorodesoxiglucosa F18 , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Tomografía de Emisión de Positrones , PronósticoRESUMEN
Blue-emitting Ca2-xMgxSiO4:Ce (0.0 ≤ x ≤ 1.0) phosphors were successfully synthesized and characterized. Rietveld refinement revealed that four main phases exist within the solid-solution range of CaO-MgO-SiO2, namely, ß-Ca2SiO4 (Mg (x) = 0.0), Ca14Mg2(SiO4)8 (Mg (x) = 0.25), Ca3Mg(SiO4)2 (Mg (x) = 0.5), and CaMgSiO4 (Mg (x) = 1.0). The variation of the IR modes was more prominent with increasing Mg2+ content in the Ca2-xMgxSiO4 materials. The sharing of O atoms of the SiO4-tetrahedra by the MgO6-octahedra induced weakening of the Si-O bonds, which resulted in the red shift of the [SiO4] internal modes and appearance of a Mg-O stretching vibration at â¼418 cm-1. Raman measurement revealed that the change of the Ca-O bond lengths because of the Mg2+-substitution directly reflected the frequency shift of the Si-O stretching-Raman modes. Notably, the thermal stability of Ca2-xMgxSiO4:Ce (Mg (x) > 0.0) phosphors was superior to that of ß-Ca2SiO4:Ce (Mg (x) = 0.0) as confirmed by temperature-dependent photoluminescence (PL) measurements. This indicated that Mg2+ ions play an important role in enhancement of the thermal stability. In combination with the results from PL and electroluminescence (EL), it was elucidated that the luminous efficiency of Ca2-xMgxSiO4:Ce (Mg (x) = 0.1) was approximately twice as much as ß-Ca2SiO4:Ce (Mg (x) = 0.00), directly indicating a "Mg2+-substitution effect". The large enhancements of PL, EL, and thermal stability because of Mg2+-substitution may provide a platform in the discovery of more efficient phosphors for NUV-LEDs.
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Sodium ion batteries offer promising opportunities in emerging utility grid applications because of the low cost of raw materials, yet low energy density and limited cycle life remain critical drawbacks in their electrochemical operations. Herein, we report a vanadium-based ortho-diphosphate, Na7V4(P2O7)4PO4, or VODP, that significantly reduces all these drawbacks. Indeed, VODP exhibits single-valued voltage plateaus at 3.88 V vs. Na/Na(+) while retaining substantial capacity (>78%) over 1,000 cycles. Electronic structure calculations reveal that the remarkable single plateau and cycle life originate from an intermediate phase (a very shallow voltage step) that is similar both in the energy level and lattice parameters to those of fully intercalated and deintercalated states. We propose a theoretical scheme in which the reaction barrier that arises from lattice mismatches can be evaluated by using a simple energetic consideration, suggesting that the presence of intermediate phases is beneficial for cell kinetics by buffering the differences in lattice parameters between initial and final phases. We expect these insights into the role of intermediate phases found for VODP hold in general and thus provide a helpful guideline in the further understanding and design of battery materials.
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Difosfatos/química , Suministros de Energía Eléctrica , Compuestos de Vanadio/química , Cristalografía , Electroquímica , Cinética , Modelos Teóricos , Difracción de Rayos XRESUMEN
BACKGROUND: Triple-negative breast cancer (TNBC) has a high risk of relapse and there are few chemotherapy options. Although 5-hydroxytryptamine (5-HT, serotonin) signaling pathways have been suggested as potential targets for anti-cancer drug development, the mechanism responsible for the action of 5-HT in TNBC remains unknown. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to measure mRNA and protein levels, respectively. Cell proliferation was measured using CellTiter 96 Aqueous One Solution. siRNA transfection was used to assess involvement of genes in cancer invasion, which were identified by Matrigel transwell invasion assay. Levels of 5-HT and vascular endothelial growth factor (VEGF) were measured using ELISA kits. Chick chorioallantoic membrane (CAM) assay and mouse tumor model were used to investigate the in vivo effects of SB269970, a 5-HT7 receptor antagonist, and BJ-1113, a novel synthetic compound. RESULTS: TNBC cell lines (MDA-MB-231, HCC-1395, and Hs578T) expressed higher levels of tryptophan hydroxylase 1 (TPH1) than hormone-responsive breast cancer cell lines (MCF-7 and T47D). In MDA-MB-231 cells, 5-HT promoted invasion and proliferation via 5-HT7 receptor, and interestingly, the stimulatory effect of 5-HT on MDA-MB-231 cell invasion was stronger than its effect on proliferation. Likewise, downstream signaling pathways of 5-HT7 differed during invasion and proliferation, that is, Gα-activated cAMP and Gßγ-activated kinase signaling during invasion, and Gßγ-activated PI3K/Akt signaling during proliferation. Also, 5-HT increased the protein expressions of TPH1 and VEGF in MDA-MB-231 cells. These results provide insight of the stimulatory effect of 5-HT on breast cancer progression; 5-HT was found to act more strongly during the first stage of metastasis (during invasion and migration) than during the later proliferative phase after local invasion. Interestingly, these actions of 5-HT were inhibited by BJ-1113, a 6-amino-2,4,5-trimethylpyridin-3-ol analog. BJ-1113 blocked intracellular signaling pathways initiated by 5-HT7 receptor activation, and exhibited anti-proliferative and anti-invasive activities against MDA-MB-231 cells. Furthermore, the inhibitory effect of BJ-1113 against MDA-MB-231 tumor growth was greater than that of SB269970, a 5-HT7 receptor antagonist. CONCLUSIONS: 5-HT7 receptor which mediates 5-HT-induced cancer progression is a potential therapeutic target in TNBC, and BJ-1113 offers a novel scaffold for the development of anti-cancer agents against TNBC.
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Comunicación Autocrina , Receptores de Serotonina/genética , Serotonina/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Triptófano Hidroxilasa/genética , Animales , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , AMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Humanos , Ratones , Modelos Biológicos , Receptores de Serotonina/metabolismo , Serotonina/farmacología , Antagonistas de la Serotonina/farmacología , Transducción de Señal/efectos de los fármacos , Neoplasias de la Mama Triple Negativas/patología , Triptófano Hidroxilasa/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Eu(2+)-activated M5(PO4)3X (M = Ca, Sr, Ba; X = F, Cl, Br) compounds providing different alkaline-earth metal and halide ions were successfully synthesized and characterized. The emission peak maxima of the M5(PO4)3Cl:Eu(2+) (M = Ca, Sr, Ba) compounds were blue-shifted from Ca to Ba (454 nm for Ca, 444 nm for Sr, and 434 nm for Ba), and those of the Sr5(PO4)3X:Eu(2+) (X = F, Cl, Br) compounds were red-shifted along the series of halides, F â Cl â Br (437 nm for F, 444 nm for Cl, and 448 nm for Br). The site selectivity and occupancy of the activator ions (Eu(2+)) in the M5(PO4)3X:Eu(2+) (M = Ca, Sr, Ba; X = F, Cl, Br) crystal lattices were estimated based on theoretical calculation of the 5d â 4f transition energies of Eu(2+) using LCAO. In combination with the photoluminescence measurements and theoretical calculation, it was elucidated that the Eu(2+) ions preferably enter the fully oxygen-coordinated sites in the M5(PO4)3X:Eu(2+) (M = Ca, Sr, Ba; X = F, Cl, Br) compounds. This trend can be well explained by "Pauling's rules". These compounds may provide a platform for modeling a new phosphor and application in the solid-state lighting field.