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1.
Langmuir ; 40(13): 6786-6805, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38503426

RESUMEN

Traditional heterogeneous catalysts are affected in the catalytic hydrogenation of PS by the scale effect, viscosity effect, adhesion effect, and conformational effect, resulting in poor activity and stability. Monolithic Pd-CNTs@FN catalysts could eliminate or weaken the impact of these negative effects. We grew nitrogen-doped carbon nanotubes (NCNTs) on monolithic-foamed nickel (FN) and investigate their growth mechanism. Meanwhile, the feasibility of using the NCNTs@FN carrier for PS hydrogenation reaction was also verified. The growth of NCNTs on FN can be divided into 3 stages: initial growth stage, stable growth stage, and supersaturation stage. Finally, a three-layer structure of NCNT layer, dense carbon layer, and FN skeleton is formed. Two types of structures, nickel-doped carbon nanotubes (NiCNTs) and C-Ni alloy, are formed by combining C and Ni, while four nitrogen-doped structures, NPD, NPR, NG, and NO, are formed by C and N. The prepared carrier exhibited an extremely outstanding specific surface area (2.829 × 106 cm2/g) and strength (no NCNTs falling off after 24 h 500 rpm agitation), as well as high catalytic activity for PS hydrogenation after loaded with Pd (2.13 ± 0.95 nm), with a TOF of up to 27.6 gPS/(gPd•h). After 8 repetitions of the catalyst, there was no significant decrease in activity. This proves the excellent performance of Pd-NCNTs@FN in polymer hydrogenation reactions, laying a solid foundation for further research on the mechanism of NCNTs promoting PS hydrogenation and regulating the growth of NCNTs.

2.
Ann Neurol ; 93(2): 244-256, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36088542

RESUMEN

OBJECTIVE: Despite the increasing number of genes associated with Charcot-Marie-Tooth (CMT) disease, many patients currently still lack appropriate genetic diagnosis for this disease. Autosomal dominant mutations in aminoacyl-tRNA synthetases (ARSs) have been implicated in CMT. Here, we describe causal missense mutations in the gene encoding seryl-tRNA synthetase 1 (SerRS) for 3 families affected with CMT. METHODS: Whole-exome sequencing was performed in 16 patients and 14 unaffected members of 3 unrelated families. The functional impact of the genetic variants identified was investigated using bioinformatic prediction tools and confirmed using cellular and biochemical assays. RESULTS: Combined linkage analysis for the 3 families revealed significant linkage (Zmax LOD = 6.9) between the genomic co-ordinates on chromosome 1: 108681600-110300504. Within the linkage region, heterozygous SerRS missense variants segregated with the clinical phenotype in the 3 families. The mutant SerRS proteins exhibited reduced aminoacylation activity and abnormal SerRS dimerization, which suggests the impairment of total protein synthesis and induction of eIF2α phosphorylation. INTERPRETATION: Our findings suggest the heterozygous SerRS variants identified represent a novel cause for autosomal dominant CMT. Mutant SerRS proteins are known to impact various molecular and cellular functions. Our findings provide significant advances on the current understanding of the molecular mechanisms associated with ARS-related CMT. ANN NEUROL 2023;93:244-256.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Serina-ARNt Ligasa , Humanos , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Serina-ARNt Ligasa/genética , Mutación , Heterocigoto , Mutación Missense/genética
3.
Ann Neurol ; 92(3): 512-526, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35700120

RESUMEN

OBJECTIVE: Oculopharyngodistal myopathy (OPDM) is an adult-onset neuromuscular disease characterized by progressive ptosis, dysarthria, ophthalmoplegia, and distal muscle weakness. Recent studies revealed that GGC repeat expansions in 5'-UTR of LRP12, GIPC1, and NOTCH2NLC are associated with OPDM. Despite these advances, approximately 30% of OPDM patients remain genetically undiagnosed. Herein, we aim to investigate the genetic basis for undiagnosed OPDM patients in two unrelated Chinese Han families. METHODS: Parametric linkage analysis was performed. Long-read sequencing followed by repeat-primed polymerase chain reaction and amplicon length polymerase chain reaction were used to determine the genetic cause. Targeted methylation sequencing was implemented to detect epigenetic changes. The possible pathogenesis mechanism was investigated by quantitative polymerase chain reaction, immunoblotting, RNA fluorescence in situ hybridization, and immunofluorescence staining of muscle biopsy samples. RESULTS: The disease locus was mapped to 12q24.3. Subsequently, GGC repeat expansion in the promoter region of RILPL1 was identified in six OPDM patients from two families, findings consistent with a founder effect, designated as OPDM type 4. Targeted methylation sequencing revealed hypermethylation at the RILPL1 locus in unaffected individuals with ultralong expansion. Analysis of muscle samples showed no significant differences in RILPL1 mRNA or RILPL1 protein levels between patients and controls. Public CAGE-seq data indicated that alternative transcription start sites exist upstream of the RefSeq-annotated RILPL1 transcription start site. Strand-specific RNA-seq data revealed bidirectional transcription from the RILPL1 locus. Finally, fluorescence in situ hybridization/immunofluorescence staining showed that both sense and antisense transcripts formed RNA foci, and were co-localized with hnRNPA2B1 and p62 in the intranuclear inclusions of OPDM type 4 patients. INTERPRETATION: Our findings implicate abnormal GGC repeat expansions in the promoter region of RILPL1 as a novel genetic cause for OPDM, and suggest a methylation mechanism and a potential RNA toxicity mechanism are involved in OPDM type 4 pathogenesis. ANN NEUROL 2022;92:512-526.


Asunto(s)
Distrofias Musculares , Adulto , Humanos , Hibridación Fluorescente in Situ , Cuerpos de Inclusión Intranucleares/patología , Distrofias Musculares/genética , Linaje , ARN , Expansión de Repetición de Trinucleótido/genética
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2296-2299, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30440865

RESUMEN

Evoked tactile sensation (ETS) is induced with stimulation of areas in the projected finger map (PFM) in the stump skin of forearm amputees. The aim of the present study is to further explore the neural correlation of the ETS with central activities in the somatosensory cortex (SI). Two forearm amputees were recruited to participate in this study. The neuroimaging technique of Magnetoencephalography (MEG) was employed to reveal the activities in the somatosensory cortex (SI), while the thumb and little finger areas in the PFM and the thumb and little finger of the contralateral hand were stimulated with a bi-phasic current pulse train. In one subject, local anesthesia was applied to the skin areas of the thumb and little finger of the PFM to examine the effects of blocking peripheral nerve transmission on the central activities in SI. Results obtained in the two subjects indicated that stimulation of the thumb and little finger areas in the PFM of amputated side produced the similar neural activities in the somatosensory cortex as those of stimulating the thumb and little finger of the contralateral hand, both of which were consistent with the homunculus organization of the SI cortex. The intensity of SI cortical activities was proportional to the intensity of the amplitude of peripheral stimulation. In particular, local anesthesia reduced the intensity of central activities in SI as revealed by the MEG response, as well as the sensitivity of ETS as reported by the subject. This neural correlation appears to suggest that the finger areas in the PFM in the stump skin are neuroanatomically connected to the finger areas of the somatosensory cortex. Thus, electrical stimulation of the PFM can induce natural sensation as that of normal fingers. This establishes the neural basis of natural sensory feedback from the prosthetic hand to the forearm amputee with finger-to-finger specificity.


Asunto(s)
Corteza Somatosensorial , Tacto , Mapeo Encefálico , Dedos , Mano , Humanos , Magnetoencefalografía
6.
J Hazard Mater ; 329: 222-229, 2017 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-28178637

RESUMEN

Thermal activated serpentine with high adsorption capacity for heavy metals was prepared. The batch experiment studies were conducted to evaluate the adsorption performance of Cd2+ in aqueous solution using thermal activated serpentine as adsorbent. These samples before and after adsorption were characterized by XRD, FT-IR, SEM, XPS, and N2 adsorption-desorption at low temperature. It was found that serpentine with layered structure transformed to forsterite with amorphous structure after thermal treatment at over 700°C, while the surface area of the samples was increased with activated temperature and the serpentine activated at 700°C (S-700) presented the largest surface area. The pH of solution after adsorption was increased in different degrees due to hydrolysis of MgO in serpentine, resulting in enhancing adsorption of Cd2+. The S-700 exhibited the maximum equilibrium adsorption capacity (15.21mg/g), which was 2 times more than pristine serpentine. Langmuir isotherm was proved to describe the equilibrium adsorption data better than Freundlich isotherm and pseudo second order kinetics model could fit the adsorption kinetics processes well. Based on the results of characterization with XPS and XRD, the adsorption mechanisms could be explained as primarily formation of CdCO3 and Cd(OH)2 precipitation on the surface of serpentine.

7.
Neurosci Lett ; 636: 95-100, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-27818350

RESUMEN

OBJECTIVE: The study aimed to explore the modification to cortical oscillations of Parkinson disease (PD) patients by subthalamic nucleus deep brain stimulation (STN DBS). METHODS: With Magnetoencephalogram (MEG) detection, we examined the changes in absolute power spectrum of cortical oscillations in the PD patients with the treatment of STN DBS. RESULTS: The power analysis of PD patients showed a dominant over-synchronization of alpha and beta bands in temporal and occipital areas relative to the healthy control subjects. STN DBS on-state showed marked power increase in the gamma band of PD patients in the frontal and parietal relative to the DBS off-state. The alleviation of motor symptoms by STN DBS negatively correlated to the increase of high gamma oscillation in the right frontal cortex, and also correlated to the suppression of the alpha and beta oscillations in the right temporal cortex. CONCLUSION: The treatment of STN DBS to PD patients might involve the augmentation of gamma activity and suppression of alpha and beta activities in cortical oscillations.


Asunto(s)
Corteza Cerebral/fisiopatología , Estimulación Encefálica Profunda , Enfermedad de Parkinson/fisiopatología , Ritmo alfa , Ritmo beta , Femenino , Ritmo Gamma , Humanos , Magnetoencefalografía , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/cirugía , Periodicidad
8.
Nanoscale ; 8(9): 5226-34, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-26878901

RESUMEN

An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ ≥ 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron-hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion.

9.
Sci Rep ; 5: 11066, 2015 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-26067607

RESUMEN

The ubiquitin-protein ligase E3C (UBE3C) belongs to the E3 ligase enzyme family and implicates in the ubiquitin-proteasome pathway, thus regulates physiological and cancer-related processes. Here, we investigated the expression and roles of UBE3C in glioma. We demonstrated that UBE3C was overexpressed in glioma tissues and cell lines. Inhibition of UBE3C expression in glioma cells significantly decreased cell migration and invasion in vitro. Mechanistically, we disclosed that UBE3C physically interacted with and ubiquitinated tumor suppressor gene annexin A7 (ANXA7), resulting in ubiquitination and degradation of ANXA7. Our results also revealed that increased UBE3C expression was accompanied by a reduction in ANXA7 protein expression in glioma tissues, but not ANXA7 mRNA. Importantly, the inhibition of ANXA7 expression in gliomas cells with UBE3C interference could rescue the cell invasion. Clinically, UBE3C overexpression significantly correlated with high-grade tumors (p < 0.05), poor overall survival, and early tumor recurrence. Thus, our data reveal that high UBE3C expression contributes to glioma progression by ubiquitination and degradation of ANXA7, and thus presents a novel and promising target for glioma therapy.


Asunto(s)
Anexina A7/metabolismo , Glioma/metabolismo , Proteolisis , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/biosíntesis , Ubiquitinación , Anexina A7/genética , Línea Celular Tumoral , Supervivencia Celular , Regulación del Desarrollo de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Glioma/genética , Glioma/patología , Humanos , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genética
10.
Sci Rep ; 3: 1024, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23289066

RESUMEN

Herein we developed a new "smart" Gd-based MR contrast agent (i.e., 1) which is susceptive to furin, a protease overexpressed in tumor. Under the action of furin, 1 condenses to form dimers (1-Ds) and the latter self-assemble into gadolinium nanparticles (Gd-NPs). Relaxivity of 1-D is more than 2 folds of those of 1 and magnevist at 1.5 T, and 1.4 folds of that of 1 at 3 T. Intracellular condensation of 1 in furin-overexpressed MDA-MB-468 cells was proven with direct two-photon laser microscopy (TPLM) fluorescence imaging of the cells incubated with the europium analog of 1 (i.e., 2). Intracellular Gd-NPs of 1 were uncovered and characterized for the first time. MRI of MDA-MB-468 tumors showed that 1 has enhanced MR contrast within the tumors than that of its scrambled control 1-Scr.


Asunto(s)
Medios de Contraste/química , Gadolinio/química , Nanopartículas del Metal/química , Animales , Línea Celular Tumoral , Medios de Contraste/síntesis química , Dimerización , Europio/química , Furina/metabolismo , Humanos , Imagen por Resonancia Magnética , Nanopartículas del Metal/ultraestructura , Ratones , Ratones Desnudos , Microscopía Confocal , Neoplasias/diagnóstico por imagen , Radiografía , Trasplante Heterólogo
11.
Org Biomol Chem ; 9(20): 6917-9, 2011 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-21879136

RESUMEN

One multifunctional small molecule can undergo a natural condensation reaction under the control of reducing agent to generate amphiphilic oligomers which quickly self-assemble supramolecular nanoparticles or form crosslinked, reversibly degradable polymers.

12.
Regul Pept ; 172(1-3): 30-4, 2011 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-21889546

RESUMEN

Oxytocin (OT) has been reported to have a potential protective effect on stress-induced functional gastrointestinal disorders. This study determined whether colonic contraction in adults was affected by antenatal maternal hypoxia, and whether OT is involved in antenatal maternal hypoxia induced colonic contraction disorder. Isometric spontaneous contractions were recorded in colonic longitudinal muscle strips in order to investigate colonic contractions and the effects of exogenous OT on the contraction in antenatal maternal hypoxia and control mice. Both high potassium and carbachol-induced contractions of proximal colon but not distal colon were reduced in antenatal maternal hypoxia mice. Exogenous OT decreased the contractions of proximal colonic smooth muscle strips in control mice, while it increased contractions in antenatal maternal hypoxia mice. OT increased the contractions of distal colonic smooth muscle strips in both antenatal maternal hypoxia and control mice. Hexamethonium blocked the OT-induced potentiation of proximal colon but not distal colon in antenatal maternal hypoxia mice. These results suggest that exogenous oxytocin reverses the decrease of proximal colonic smooth muscle contraction in antenatal maternal hypoxia mice via ganglia.


Asunto(s)
Colon/efectos de los fármacos , Colon/fisiología , Ganglios/citología , Hipoxia/fisiopatología , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Oxitocina/farmacología , Animales , Animales Recién Nacidos , Colon/metabolismo , Femenino , Ganglios/efectos de los fármacos , Ganglios/metabolismo , Motilidad Gastrointestinal/efectos de los fármacos , Motilidad Gastrointestinal/fisiología , Ratones , Ratones Endogámicos BALB C , Músculo Liso/citología , Embarazo
13.
Chem Commun (Camb) ; 47(37): 10320-2, 2011 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-21853204

RESUMEN

A caspase-3 controlled condensation was applied to self-assemble biotinylated nanoparticles for capturing FITC-labelled streptavidin and subsequently turning on the fluorescence signal.


Asunto(s)
Caspasa 3/metabolismo , Nanopartículas/química , Biotinilación , Fluoresceína-5-Isotiocianato/química , Colorantes Fluorescentes/química , Proteínas Inmovilizadas/química , Proteínas Inmovilizadas/metabolismo , Espectrometría de Fluorescencia , Estreptavidina/química , Estreptavidina/metabolismo
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(3): 616-20, 2010 Mar.
Artículo en Chino | MEDLINE | ID: mdl-20496672

RESUMEN

Series of Tm3+/Yb3+ co-doped GdF3 powders were synthesized through an easy and mild hydrothermal method. The phase and purity of powders were characterized by powder X-ray diffraction (XRD) (Rigaku RU-200b). The morphologies of the samples were characterized by field emission scanning electron microscopy (FE SEM) (Hitachi S-4800). The ultraviolet (UV) up-conversion (UC)emission spectra were recorded by a fluorescence spectrophotometer (Hitachi F-4500) with a 980 nm semiconductor continuous wave laser diode as the excitation source. And the luminescent dynamics was measured by excitation with 980 nm using an optical parameter oscillator (OPO) laser pumped by a pulsed Nd : YAG laser with a pulse duration of 10 ns, repetition frequency of 10 Hz, and the signal was recorded by using a monochromator and an oscillograph. Under 980 nm excitation, Gd3+, acting as a kind of host ion in the studied system, and its UV UC emissions were observed and studied. The luminescent dynamics of the characteristic emission of Gd3+ (311.6 nm, 6P7/2 --> 8S7/2) was explored and studied. The luminescent dynamics analysis results indicated that, on UV UC emissions of Gd3+, Yb3+ ions served as primary sensitizer ions successively transferring energy to Tm3+ to populate the 3P2 level. Then, Tm3+ ions served as secondary sensitizer ions transferring energy to populate the multiple 6 I(J) states of Gd3+ 3P2 --> 3H6 (Tm3+): 8S7/2 --> 6 I(J) (Gd3+). Further, 6D(J) levels were populated through other energy transfer processes between Gd3+ and Yb3+ or Tm3+. Finally, UV UC emissions from the excited 6D9/2, 6 I(J), 6P5/2, and 6P7/2 states to the ground state 8S7/2 were observed. Meanwhile, Tm3+ acted as activator in its own UC emissions, and the article did not put emphasis on those except the 3P2 and 1 I6 levels to the ground state 3 H6 transitions. Especially, the dependences of UV UC emissions of Gd3+ on the Yb3+ concentrations, the Tm3+ concentrations, the annealing temperatures, and the excitation power densities of the 980 nm semiconductor continuous wave laser diode were studied, too.

16.
Neurosci Bull ; 25(2): 87-93, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19290027

RESUMEN

OBJECTIVE: Numerous studies have described both motor defects and cognitive impairments in several strains of rodents following 3-nitropropionic acid (3-NP) intoxication. In the present study, we investigated spatial recognition memory in Kunming mice that just recovered from motor defects induced by 3-NP. METHODS: Mouse model was made by systemic subacute 3-NP treatment, and spatial recognition memory was measured through the Y-maze Test, a simple two-trial recognition test. RESULTS: (1) On day 15 following 3-NP treatment, affected Kunming mice did not show motor defects in the Rotarod test and presented normal gait again. (2) In the following Y-maze test after 1h interval, the percentage (90.0%) of mice showing novel arm preference in 3-NP treatment group was significantly higher than the random chance level (50%), although it was only slightly higher than that (83.3%) in control group. On day 45 after 3-NP treatment, mice failed to choose unfamiliar novel arm as first choice, and the same occured in the control group. (3) For both post-intoxicated (on day 15 and day 45 following 3-NP treatment) and control groups, the duration in the novel arm and the frequency of entering it, were longer and higher compared with familiar start and other arms. For these mice that recently recovered from motor defects following 3-NP intoxication, no spatial memory deficits were observed through Y-maze Test. CONCLUSION: Kunming mice used in our assays might possess resistance to cognitive impairment induced by 3-NP, which is consistent with previous findings in Swiss EPM-M1 mice.


Asunto(s)
Convulsivantes/toxicidad , Trastornos de la Memoria/etiología , Actividad Motora/efectos de los fármacos , Trastornos del Movimiento/etiología , Nitrocompuestos/toxicidad , Intoxicación , Propionatos/toxicidad , Recuperación de la Función/fisiología , Animales , Conducta Animal , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Ratones Endogámicos , Intoxicación/complicaciones , Intoxicación/etiología , Recuperación de la Función/efectos de los fármacos , Prueba de Desempeño de Rotación con Aceleración Constante , Factores de Tiempo
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(12): 2768-71, 2008 Dec.
Artículo en Chino | MEDLINE | ID: mdl-19248479

RESUMEN

Novel red phosphor, Eu3+ -doped oxyphosphate (La3 PO7:Eu3+), was synthesized by a solid state method under high temperature. All the starting materials were analytical grade. La2O3, EuO3 and (NH4)2HPO4 weighed in appropriated molar ratios and ground in an agate mortar. Then the powder was treated under 1000 degrees C. The crystal phase of La3PO7:Eu3+ was investigated by X-ray diffraction (XRD) using a Cu target radiation resource (lamda = 1.54078 ?) and exhibited prominent peaks accordant with JCPDS standard card (33-0720) of La3PO7 in monoclinic phase. Emission and excitation spectra of La3PO7:Eu3+ were recorded at room temperature using a fluorescence spectrometer (Hitachi F-4500). Under 254 nm excitation, intense red fluorescence was observed from La3PO7:Eu3+, which was assigned to the (5)D0-->(7)F2 transition of Eu3+ ions. The intensity of the (5)D0-->(7)F2 transition is stronger than that of the (5)D0-->(7)F1 transition, showing that the Eu3+ ions were in the non-centrosym-metric sites in La3PO7. The CommissionIn-ternational DeL" Eclairage (CIE) coordinate of La3PO7:Eu3+ is (0.63,0.37) in the red area of CIE1931 XY chromaticity coordinate graph and close to that of Y2o3:Eu3+, but the cost of La3PO7 host is lower. This novel material may have potential applications in plasma display panels and Hg-free fluorescent lamps in the future.

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