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1.
J Am Chem Soc ; 146(26): 17559-17565, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38916517

RESUMEN

Despite recent advances in porous organic molecular crystals, the engineering of dual-pore systems within the intermolecular voids remains a significant challenge. In this study, we have achieved the crystallization-induced social self-sorting of "quasi-racemic" dialdehydes into a macrocyclic imine. X-ray crystallographic analysis unambiguously characterizes the resulting structure as incorporating two quasi-racemate pairs with four diamine molecules. Notably, different alkyl substituents on the quasi-racemates afford two types of one-dimensional pores within the macrocyclic imine crystal. The different adsorption properties of these pores were substantiated through adsorption experiments. An intriguing helical arrangement of guest molecules was observed within one of the pores. This study provides pioneering evidence that the social self-sorting of quasi-racemates offers a new methodology for creating dual-functional supramolecular materials.

2.
Exp Eye Res ; 227: 109382, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36634838

RESUMEN

Intraocular pressure (IOP) is the most important risk factor for the onset and progression of glaucoma. IOP reduction has been proven effective in the treatment of glaucoma. IOP is controlled by the production and outflow of the aqueous humor (AH), and the trabecular meshwork (TM) is the main pathway for AH drainage from the eye. However, there are few conventional IOP-lowering treatments that target TM, and there is a need for such treatments. In this study, we screened for the expression level of fibronectin as an indicator and identified an activin receptor-like kinase (ALK) 5 inhibitor. Western blot analysis showed that SB431542, an ALK 5 inhibitor, reduced fibronectin and α-SMA expression. Moreover, a single dose of the ALK5 inhibitor SB431542 reduced IOP in mice, and the IOP-lowering effect of the ALK5 inhibitor was greater than that of a Rho-associated coiled-coil-containing protein kinase inhibitor (Y-27632). Repeated dosing with ALK5 inhibitor eye drops (once daily) enhanced the murine IOP-lowering effect. Furthermore, ALK5 inhibition decreased the expression of extracellular matrix (ECM) mRNA and suppressed ECM production. These findings suggest that ALK5 inhibitors may contribute to the development of new treatments for glaucoma that target the TM.


Asunto(s)
Glaucoma , Malla Trabecular , Ratones , Animales , Malla Trabecular/metabolismo , Presión Intraocular , Fibronectinas/metabolismo , Humor Acuoso/metabolismo , Glaucoma/tratamiento farmacológico , Glaucoma/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo
3.
Exp Eye Res ; 215: 108917, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34973946

RESUMEN

Glaucoma is a neurodegenerative disease that leads to blindness, and lowering intraocular pressure (IOP) is very important in glaucoma treatment. The trabecular meshwork is responsible for aqueous humor outflow, and the accumulation of fibronectin in trabecular meshwork is known to cause ocular hypertension. We have already shown that Piezo1 activation has an IOP lowering effect in mice and suppresses fibronectin expression level in human trabecular meshwork cells (HTMC). In this study, we report the mechanism of the reduction of fibronectin caused by Piezo1 activation. Activation of Piezo1 in HTMC showed increased expression of matrix metalloproteinase-2 (MMP-2) and cyclooxygenase (COX)-2, and decreased fibronectin expression. In addition, Piezo1 activation enhanced phosphorylation of cytosolic phospholipase A2 (cPLA2), and inhibitors targeting cPLA2 and COX-2 suppressed Yoda 1, a Piezo1 agonist, induced fibronectin reduction. These results indicate that the arachidonic acid cascade underlies this reaction, and, in support of this hypothesis, activation of Piezo1 promoted secretion of prostaglandin F2α (PGF2α) in HTMC. These results indicate that the activation of Piezo1 in HTMC promotes the degrading of fibronectin by promoting the arachidonic acid cascade and increasing the expression of PGF2α and MMP-2.


Asunto(s)
Ácido Araquidónico , Dinoprost , Fibronectinas , Glaucoma , Enfermedades Neurodegenerativas , Hipertensión Ocular , Animales , Humor Acuoso/metabolismo , Ácido Araquidónico/metabolismo , Dinoprost/metabolismo , Fibronectinas/metabolismo , Glaucoma/metabolismo , Presión Intraocular , Canales Iónicos/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Ratones , Enfermedades Neurodegenerativas/metabolismo , Hipertensión Ocular/metabolismo , Fosfolipasas A2 Citosólicas/metabolismo , Fosfolipasas A2 Citosólicas/farmacología , Malla Trabecular/metabolismo
4.
J Org Chem ; 87(3): 1641-1660, 2022 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-34082529

RESUMEN

We studied the Z/E preference of N-phenylthioacetamide (thioacetanilide) derivatives in various solvents by means of 1H NMR spectroscopy, as well as molecular dynamics (MD) and other computational analyses. Our experimental results indicate that the Z/E isomer preference of secondary (NH)thioamides of N-phenylthioacetamides shows substantial solvent dependency, whereas the corresponding amides do not show solvent dependency of the Z/E isomer ratios. Detailed study of the solvent effects based on molecular dynamics simulations revealed that there are two main modes of hydrogen (H)-bond formation between solvent and (NH)thioacetamide, which influence the Z/E isomer preference of (NH)thioamides. DFT calculations of NH-thioamide in the presence of one or two explicit solvent molecules in the continuum solvent model can effectively mimic the solvation by multiple solvent molecules surrounding the thioamide in MD simulations and shed light on the precise nature of the interactions between thioamide and solvent. Orbital interaction analysis showed that, counterintuitively, the Z/E preference of NH-thioacetamides is mainly determined by steric repulsion, while that of sterically congested N-methylthioacetamides is mainly determined by thioamide conjugation.


Asunto(s)
Simulación de Dinámica Molecular , Tioamidas , Enlace de Hidrógeno , Espectroscopía de Resonancia Magnética , Solventes/química , Tioamidas/química
5.
J Nurs Manag ; 30(7): 2207-2215, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35258139

RESUMEN

AIM: This study aimed to evaluate an ethics education program developed to increase moral efficacy among nurses in an acute health care facility. BACKGROUND: Moral distress among nurses can cause serious problems in terms of hospital organisations and patient safety. To reduce moral distress and promote professional confidence in nursing practice, a strategic intervention program is needed. METHODS: An ethics education program introduced methods to increase self-efficacy in accordance with Bandura's social cognitive theory. Eight nurses were recruited from 2017 to 2019, and all conversations and discussions regarding the ethics consultation were recorded on IC recorders and analysed qualitatively. RESULTS: Four core categories-Convinced to take an active role in ethical issues; Progressed in nursing practice with ethical agency; Experienced professional transformation; and Empowered by the presence of colleagues-emerged as outcomes of the ethics education program that related to moral efficacy. CONCLUSIONS: The four core outcome categories suggested that the participants had gained confidence after taking part in the ethical education program. IMPLICATIONS FOR NURSING MANAGEMENT: The results of the participants' described behaviours and actions suggested that they would be proactive in contributing to reductions in moral distress in the future.


Asunto(s)
Ética en Enfermería , Enfermeras y Enfermeros , Humanos , Principios Morales , Comunicación , Atención a la Salud
6.
Angew Chem Int Ed Engl ; 61(48): e202211196, 2022 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-36194383

RESUMEN

Incorporating hetero-metal-atom, e.g., titanium, into zeolite frameworks can enhance the catalytic activity and selectivity in oxidation reactions. However, the rational design of zeolites containing titanium at specific sites is difficult because the precise atomic structure during synthesis process remained unclear. Here, a titanosilicate with predictable titanium distribution was synthesized by mediating vacancies in a defective MSE-type zeolite precursor, based on a pre-designed synthetic route including modification of vacancies followed by titanium insertion, where electron microscopy (EM) plays a key role at each step resolving the atomic structure. Point defects including vacancies in the precursor and titanium incorporated into the vacancy-related positions have been directly observed. The results provide insights into the role of point defects in zeolites towards the rational synthesis of zeolites with desired microscopic arrangement of catalytically active sites.

7.
Exp Eye Res ; 202: 108338, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33157126

RESUMEN

Growth differentiation factor 15 (GDF15) is a protein belonging to the transforming growth factor beta (TGF-ß) superfamily. The precursor GDF15 is cleaved and activated as a mature GDF15 by protease. GDF15 has been detected in the aqueous humor of the primary open angle glaucoma patients, however the localization and the effect on the retinal ganglion cells (RGCs) are still unknown. Thus, the purpose of this study was to elucidate the effect of GDF15 on mouse optic nerve crush (ONC) model and primary culture of rat RGCs. Immunostaining showed that the GDF15 was in the ganglion cell layer (GCL), and colocalized with GFAP-positive cells in the GCL and the optic nerve. Western blotting analysis showed that the mature GDF15 was upregulated in the retina and the optic nerve after the ONC. Intravitreal injection of GDF15 suppressed RGCs loss of the ONC model mice in vivo. The neurites length of the primary culture of rat RGCs were increased by mature GDF15 treatment. In addition, the neurotrophic effect of GDF15 was canceled by RET inhibitor treatment. These findings indicate that GDF15 has neuroprotective effect on RGCs via GFRAL-RET pathway. Therefore, GDF15 may be one of novel therapeutic targets in RGC degenerative diseases.


Asunto(s)
Factor 15 de Diferenciación de Crecimiento/farmacología , Traumatismos del Nervio Óptico/prevención & control , Degeneración Retiniana/prevención & control , Células Ganglionares de la Retina/efectos de los fármacos , Animales , Western Blotting , Células Cultivadas , Modelos Animales de Enfermedad , Proteína Ácida Fibrilar de la Glía/metabolismo , Factor 15 de Diferenciación de Crecimiento/metabolismo , Inmunohistoquímica , Masculino , Ratones , Microscopía Confocal , Compresión Nerviosa , Traumatismos del Nervio Óptico/metabolismo , Ratas , Ratas Sprague-Dawley , Degeneración Retiniana/metabolismo , Células Ganglionares de la Retina/metabolismo , Distribución Tisular , Factor de Crecimiento Transformador beta/farmacología
8.
J Pharmacol Sci ; 147(2): 211-221, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34217619

RESUMEN

Trabecular meshwork (TM) regulates the intraocular pressure (IOP) through the control of aqueous humor outflow. Previous reports show that TM cells express 11 types of mechanosensitive molecules, including Piezo 1, which sense mechanical stimuli. However, the role of Piezo 1 on TM remains unclear. Thus, in this study, we focused on the Piezo 1 and examined its role in TM cells. Immunostaining showed that Piezo 1 was expressed in mouse TM and human TM cells. Moreover, the eye drops containing Piezo 1 agonist Yoda 1 reduced the IOP in mice, and also reduced fibronectin expression level around the TM. In addition, Piezo 1 activation suppressed human TM cells migration/proliferation, and decreased fibronectin expression level. On the other hand, Piezo 1 activation increased matrix metalloproteinase (MMP)-2 expression responsible for fibronectin degradation. These findings could contribute to the development of new treatments for glaucoma.


Asunto(s)
Expresión Génica/genética , Glaucoma/genética , Glaucoma/terapia , Presión Intraocular/genética , Canales Iónicos/fisiología , Animales , Movimiento Celular/genética , Proliferación Celular/genética , Células Cultivadas , Fibronectinas/genética , Fibronectinas/metabolismo , Humanos , Canales Iónicos/genética , Canales Iónicos/metabolismo , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Ratones , Ratones Endogámicos , Terapia Molecular Dirigida , Malla Trabecular/citología , Malla Trabecular/metabolismo
9.
J Pharmacol Sci ; 147(2): 200-207, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34384568

RESUMEN

Leber hereditary optic neuropathy (LHON) is caused by mitochondrial DNA mutations and is the most common inherited mitochondrial disease. It is responsible for central vision loss in young adulthood. However, the precise mechanisms of onset are unknown. This study aimed to elucidate the mechanisms underlying LHON pathology and to discover new therapeutic agents. First, we assessed whether rotenone, a mitochondrial complex Ⅰ inhibitor, induced retinal degeneration such as that in LHON in a mouse model. Rotenone decreased the thickness of the inner retina and increased the expression levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and immunoglobulin heavy-chain binding protein (BiP). Second, we assessed whether rotenone reproduces LHON pathologies on RGC-5, a neural progenitor cell derived from the retina. Rotenone increased the cell death rate, ROS production and the expression levels of ER stress markers. During chemical compounds screening, we used anti-oxidative compounds, ER stress inhibitors and anti-inflammatory compounds in a rotenone-induced in vitro model. We found that SUN N8075, an ER stress inhibitor, reduced mitochondrial ROS production and improved the mitochondrial membrane potential. Consequently, the ER stress response is strongly related to the pathologies of LHON, and ER stress inhibitors may have a protective effect against LHON.


Asunto(s)
Compuestos de Anilina/farmacología , Descubrimiento de Drogas , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/fisiología , Atrofia Óptica Hereditaria de Leber/tratamiento farmacológico , Atrofia Óptica Hereditaria de Leber/genética , Piperazinas/farmacología , Rotenona/efectos adversos , Animales , Células Cultivadas , ADN Mitocondrial/genética , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Estrés del Retículo Endoplásmico/genética , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Potencial de la Membrana Mitocondrial/genética , Ratones Endogámicos C57BL , Terapia Molecular Dirigida , Mutación , Atrofia Óptica Hereditaria de Leber/inducido químicamente , Atrofia Óptica Hereditaria de Leber/patología , Especies Reactivas de Oxígeno/metabolismo , Retina/efectos de los fármacos , Retina/metabolismo , Retina/patología , Degeneración Retiniana/inducido químicamente , Degeneración Retiniana/genética , Degeneración Retiniana/patología
10.
Ophthalmic Res ; 64(1): 68-76, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32498067

RESUMEN

The characteristics of the conjunctival bleb are some of the most important factors for the surgical success of glaucoma filtering surgery. To improve surgical outcome, we investigated bleb histology after 3 different glaucoma surgeries. Surgery was performed in 21 white rabbits. Rabbits were randomized to trabeculectomy or implantation with EX-PRESS or a silicone tube (each n = 7). Bleb survival, intraocular pressure (IOP), and vascularity were evaluated. At 6 weeks, eyes were enucleated for histological analysis. Postoperative IOP at 2 weeks was significantly lower in the trabeculectomy and the EX-PRESS group than in the silicone tube group (p = 0.037) but not thereafter. Postoperative bleb survival (p = 0.542) and vascularity (p = 0.988) were similar among the 3 groups. Histologically, a capsule showing mild fibroblast proliferation associated with intercellular collagen was present around the surgical site. The thickness of the bleb was similar among all experimental groups, but it was significantly greater than in controls (p < 0.05). The inflammatory area did not differ between the EX-PRESS and the silicone tube group but was significantly greater in the trabeculectomy group than in the tube group (p = 0.031). A correlation between the thickness of the bleb wall and inflammation was found (r = 0.56, p < 0.01). EX-PRESS and silicone tube implants appear to be relatively inert, with little difference in biocompatibility and bleb survival. Since some degree of inflammation was still observed histologically in the bleb, more noninvasive surgical methods and more biocompatible materials may be desirable.


Asunto(s)
Conjuntiva/patología , Implantes de Drenaje de Glaucoma , Glaucoma/cirugía , Presión Intraocular/fisiología , Complicaciones Posoperatorias/diagnóstico , Trabeculectomía/efectos adversos , Animales , Modelos Animales de Enfermedad , Estudios de Seguimiento , Glaucoma/diagnóstico , Glaucoma/fisiopatología , Masculino , Conejos , Resultado del Tratamiento
11.
Int J Mol Sci ; 22(18)2021 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-34575849

RESUMEN

Cystatin C (CST3) is an endogenous cysteine protease inhibitor, which is implicated in cerebral amyloid angiopathy (CAA). In CAA, CST3 is found to be aggregated. The purpose of this study is to investigate whether this aggregation could alter the activity of the protein relevant to the molecular pathology of CAA. A system of CST3 protein aggregation was established, and the aggregated protein was characterized. The results showed that CST3 aggregated both at 80 °C without agitation, and at 37 °C with agitation in a time-dependent manner. However, the levels of aggregation were high and appeared earlier at 80 °C. Dot-blot immunoassay for oligomers revealed that CST3 could make oligomeric aggregates at the 37 °C condition. Electron microscopy showed that CST3 could make short fibrillary aggregates at 37 °C. Cathepsin B activity assay demonstrated that aggregated CST3 inhibited the enzyme activity less efficiently at pH 5.5. At 7.4 pH, it lost the inhibitory properties almost completely. In addition, aggregated CST3 did not inhibit Aß1-40 fibril formation, rather, it slightly increased it. CST3 immunocytochemistry showed that the protein was positive both in monomeric and aggregated CST3-treated neuronal culture. However, His6 immunocytochemistry revealed that the internalization of exogenous recombinant CST3 by an astrocytoma cell culture was higher when the protein was aggregated compared to its monomeric form. Finally, MTT cell viability assay showed that the aggregated form of CST3 was more toxic than the monomeric form. Thus, our results suggest that aggregation may result in a loss-of-function phenotype of CST3, which is toxic and responsible for cellular degeneration.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Amiloide/metabolismo , Cistatina C/metabolismo , Péptido Hidrolasas/metabolismo , Agregación Patológica de Proteínas/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Agregado de Proteínas , Temperatura
12.
Molecules ; 26(23)2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34885878

RESUMEN

We used computational modeling, based on Density Functional Theory, to help understand the preference for the formation of silanol nests and the substitution of Si by Ti or Al in different crystallographic positions of the MSE-type framework. All these processes were found to be energetically favorable by more than 100 kJ/mol. We suggested an approach for experimental identification of the T atom position in Ti-MCM-68 zeolite via simulation of infrared spectra of pyridine and acetonitrile adsorption at Ti. The modeling of adsorption of hydrogen peroxide at Ti center in the framework has shown that the molecular adsorption was preferred over the dissociative adsorption by 20 to 40 kJ/mol in the presence or absence of neighboring T-atom vacancy, respectively.

13.
Exp Eye Res ; 191: 107900, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31874142

RESUMEN

Piezo channel is one of the mechanosensitive channels that senses pressure and shearing stress. Previous reports show that Piezo channel is expressed in many tissues such as skin and lung and they have many important roles. In addition, the mRNA of Piezo has been detected in astrocytes in the optic nerve head of mice. However, it is not yet clear where Piezo channel localize in eye and what kind of effects it have. Thus, the purpose of this study was to determine the expression sites of Piezo channel in mouse eyes and effect of Piezo channel on retinal ganglion cells. Immunostaining analysis showed that the Piezo 1/2 were expressed in the cornea, trabecular meshwork of the anterior ocular segment, lens epithelial cells, and on the retinal ganglion cell layer. The expression of retinal Piezo 2 was increased in retinal disorder model mouse caused by high IOP. Piezo 1 agonist Yoda 1 suppressed neurite outgrowth in retinal ganglion cells. On the other hand, Piezo antagonist GsMTx4 promoted neurite outgrowth in retinal ganglion cells. These findings indicate that Piezo channel may contribute to diseases relating the IOP such as glaucoma.


Asunto(s)
Canales Iónicos/farmacología , Hipertensión Ocular/etiología , Enfermedades de la Retina/etiología , Células Ganglionares de la Retina/efectos de los fármacos , Animales , Western Blotting , Células Cultivadas , Córnea/metabolismo , Células Ependimogliales , Células Epiteliales/metabolismo , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intercelular/farmacología , Presión Intraocular , Canales Iónicos/agonistas , Canales Iónicos/antagonistas & inhibidores , Canales Iónicos/metabolismo , Cristalino/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Proyección Neuronal/fisiología , Hipertensión Ocular/metabolismo , Hipertensión Ocular/patología , Pirazinas/farmacología , Ratas , Ratas Sprague-Dawley , Enfermedades de la Retina/metabolismo , Enfermedades de la Retina/patología , Células Ganglionares de la Retina/metabolismo , Células Ganglionares de la Retina/patología , Venenos de Araña/farmacología , Tiadiazoles/farmacología , Malla Trabecular/metabolismo
14.
Neurochem Res ; 44(7): 1773-1779, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31102025

RESUMEN

Spinal muscular atrophy (SMA) is an inherited disease characterized by progressive motor neuron death and subsequent muscle weakness and is caused by deletion or mutation of survival motor neuron (SMN) 1 gene. Protecting spinal motor neuron is an effective clinical strategy for SMA. The purpose of this study was to investigate the potential effect of an anti-epileptic drug levetiracetam on SMA. In the present study, we used differentiated spinal motor neurons (MNs) from SMA patient-derived induced pluripotent stem cells (SMA-iPSCs) to investigate the effect of levetiracetam. Levetiracetam promoted neurite elongation in SMA-iPSCs-MNs. TUNEL-positive spinal motor neurons were significantly reduced by levetiracetam in SMA-iPSCs-MNs. In addition, the expression level of cleaved-caspase 3 was decreased by levetiracetam in SMA-iPSCs-MNs. Furthermore, levetiracetam improved impaired mitochondrial function in SMA-iPSCs-MNs. On the other hand, levetiracetam did not affect the expression level of SMN protein in SMA-iPSCs-MNs. These findings indicate that levetiracetam has a neuroprotective effect for SMA.


Asunto(s)
Células Madre Pluripotentes Inducidas/efectos de los fármacos , Levetiracetam/uso terapéutico , Neuronas Motoras/efectos de los fármacos , Atrofia Muscular Espinal/prevención & control , Neuritas/efectos de los fármacos , Fármacos Neuroprotectores/uso terapéutico , Apoptosis/efectos de los fármacos , Chaperonina 60/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/patología , Mitocondrias/efectos de los fármacos , Proteínas Mitocondriales/metabolismo , Neuronas Motoras/patología , Atrofia Muscular Espinal/patología , Neuritas/patología
15.
J Am Chem Soc ; 139(23): 7989-7997, 2017 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-28581728

RESUMEN

Synthesis of new zeolites with controlled pore architectures is important in the field of catalysis and separation related to chemical transformation, environmental protection, and energy-saving. Zeolites containing channels of different sizes in the same framework have been desirable. We report here the synthesis and structure of a novel aluminosilicate zeolite (designated as YNU-5), the first zeolite containing interconnected 12-, 12-, and 8-ring pores, as well as independent straight 8-ring channels. The synthesis procedure is quite simple and consists of conventional hydrothermal conditions as well as readily available starting materials. The framework structure is stable enough and Si/Al ratio is controllable between 9 and 350. Determination of the crystal structure is performed by utilizing X-ray diffraction-based techniques, revealing 9 independent tetrahedrally coordinated atoms. This robust structure is expected to be industrially valuable and several unusual combinations of composite building units are of considerable interest in an academic sense. The new zeolite YNU-5 is promising catalyst for the production of useful light olefins such as propylene and butylenes in the dimethyl ether-to-olefin reaction, when the Si/Al ratio is properly tuned by dealumination through simple acid treatments.

16.
J Org Chem ; 82(21): 11370-11382, 2017 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-28968504

RESUMEN

The conformational properties of N-acyl azoles (imidazole, pyrazole, and triazole) were examined. The N-2',4',6'-trichlorobenzoyl azoles were stable in methanol at room temperature, and no hydrolyzed products were observed over 7 days in the presence of 5% trifluoroacetic acid or 5% triethylamine in CDCl3. The high stability may be explained by the double-bond amide character caused by the steric hindrance due to the ortho-substituents in the benzoyl group. While specific E-amide preferences were observed in N-acyl pyrazoles/triazoles, the amides of the imidazoles gave a mixture of E and Z. One of the conceivable ideas to rationalize this conformational preference may be repulsive interaction between two sets of lone-pair electrons on the pyrazole 2-nitrogen (nN) and the carbonyl oxygen atoms (nO) in the Z-conformation of N-acyl pyrazoles/triazoles. However, analysis of orbital interactions suggested that in the case of the E-conformation of N-acyl pyrazoles, such electron repulsion is small because of distance. The interbond energy calculations suggested that the Z-conformer is involved in strong vicinal σ-σ repulsion along the amide linkage between the σN1N2 and σC1C2 orbitals in the anti-periplanar arrangement and between the σN1C5 and σC1C2 orbitals in the syn-periplanar arrangement, which lead to the overwhelming E-preference in N-acyl pyrazoles/triazoles. In the case of N-acyl imidazoles, similar vicinal σ-σ repulsions were counterbalanced, leading to a weak preference for the E-conformer over the Z-conformer. The chemically stable and E-preferring N-acyl azoles may be utilized as scaffolds in future drug design.

17.
J Diabetes Complications ; 38(6): 108746, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38749296

RESUMEN

AIMS: This study aimed to investigate the relationship between changes in glucose metabolism and body composition in patients with diabetes. METHODS: We included 380 patients with type 2 diabetes, who underwent bioelectrical impedance analysis, in this longitudinal study. Changes in HbA1c (ΔHbA1c) levels and body composition indices were compared between baseline and 6 months. A multivariate analysis was performed to examine the relationship between ΔHbA1c and changes in body composition. RESULTS: HbA1c levels were significantly decreased at 6 months (P < 0.01), but there was no significant change in BMI. A linear multiple regression analysis showed that ΔHbA1c was negatively correlated with changes in muscle mass (ß = -0.18; P = 0.047) and bone mineral content (ß = -0.28; P < 0.001), but there was no significant association between ΔHbA1c levels and a change in body fat percentage. CONCLUSIONS: This study shows a limited association between short-term changes in glucose metabolism and changes in body composition in patients with type 2 diabetes. Therefore, interventions aimed at reducing adiposity may not affect glucose metabolism in the short term, while interventions focused on maintaining or enhancing muscle mass and bone mineral content may play an important role in diabetes management.


Asunto(s)
Composición Corporal , Densidad Ósea , Diabetes Mellitus Tipo 2 , Hemoglobina Glucada , Músculo Esquelético , Humanos , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Masculino , Hemoglobina Glucada/análisis , Hemoglobina Glucada/metabolismo , Femenino , Persona de Mediana Edad , Composición Corporal/fisiología , Anciano , Estudios Longitudinales , Músculo Esquelético/metabolismo , Densidad Ósea/fisiología , Impedancia Eléctrica , Glucemia/metabolismo , Glucemia/análisis , Adiposidad/fisiología , Índice de Masa Corporal
18.
Chemistry ; 19(24): 7780-6, 2013 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-23606200

RESUMEN

An aluminum-rich MSE-type zeolite (Si/Al is as small as 7) has been successfully synthesized in a remarkably short crystallization period of only 3 days by the hydrothermal conversion of an FAU-type zeolite, presumably by the assembly of four-membered-ring (4-R) aluminosilicate oligomers supplied by the double 6-R (D6R) components of the FAU framework with the aid of the structure-directing agents and seed crystals. The dealuminated version of the aluminum-rich MSE-type zeolite showed a high level of coke durability in addition to a significant yield of propylene, which indicates that this novel zeolitic material is suitable for industrial applications as a highly selective and long-lived catalyst.

19.
Phys Chem Chem Phys ; 15(32): 13523-31, 2013 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-23824320

RESUMEN

The paramagnetic doping of Cu(2+) in both mesoporous silica materials and microporous silicate crystals (zeolites) can be used effectively to enhance the signal intensity of (29)Si solid state magic angle spinning NMR, as a result of shortening of the spin-lattice relaxation time, T1, by the paramagnetic effect, because of the Cu(2+) electronic relaxation time in the range of 10(-8) s. This leads to drastically reduced data-collection times, typically 80-fold shorter than that in mesoporous silica. We found that the estimated range of the paramagnetic effect of Cu(2+) doping in porous silicates was at least 1 nm.


Asunto(s)
Cobre/química , Dióxido de Silicio/química , Silicio/química , Zeolitas/química , Espectroscopía de Resonancia Magnética , Tamaño de la Partícula , Porosidad , Propiedades de Superficie
20.
J Biosci Bioeng ; 136(3): 239-245, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37344278

RESUMEN

This study describes a co-culture system of human skin equivalents (HSEs) and dorsal root ganglion (DRG) neurons. We prepared spheroids of mouse DRG neurons with or without Schwann cells (SCs). Spheroids comprising DRG neurons and SCs showed longer neurite extensions than those comprising DRG neurons alone. Neurite extension of more than 1 mm was observed from spheroids cultured inside HSEs, whereas neurite extension was primarily observed on the surface of HSEs from spheroids cultured on HSEs. We propose that our model may be a useful tool for studying neurite extension in the human skin.


Asunto(s)
Neuritas , Neuronas , Humanos , Ratones , Animales , Técnicas de Cocultivo , Neuritas/fisiología , Células de Schwann , Células Cultivadas
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