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A novel antiferroelectric material, PbSnO3 (PSO), was introduced into a resistive random access memory (RRAM) to reveal its resistive switching (RS) properties. It exhibits outstanding electrical performance with a large memory window (>104), narrow switching voltage distribution (±2 V), and low power consumption. Using high-resolution transmission electron microscopy, we observed the antiferroelectric properties and remanent polarization of the PSO thin films. The in-plane shear strains in the monoclinic PSO layer are attributed to oxygen octahedral tilts, resulting in misfit dislocations and grain boundaries at the PSO/SRO interface. Furthermore, the incoherent grain boundaries between the orthorhombic and monoclinic phases are assumed to be the primary paths of Ag+ filaments. Therefore, the RS behavior is primarily dominated by antiferroelectric polarization and defect mechanisms for the PSO structures. The RS behavior of antiferroelectric heterostructures controlled by switching spontaneous polarization and strain, defects, and surface chemistry reactions can facilitate the development of new antiferroelectric device systems.
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Recently, perovskite (PV) oxides with ABO3 structures have attracted considerable interest from scientists owing to their functionality. In this study, CaFeOx is introduced to reveal the resistive switching properties and mechanism of oxygen vacancy transition in PV and brownmillerite (BM) structures. BM-CaFeO2.5 is grown on an Nb-STO conductive substrate epitaxially. CaFeOx exhibits excellent endurance and reliability. In addition, the CaFeOx also demonstrates an electroforming-free characteristic and multilevel resistance properties. To construct the switching mechanism, high-resolution transmission electron microscopy is used to observe the topotactic phase change in CaFeOx . In addition, scanning TEM and electron energy loss spectroscopy show the structural evolution and valence state variation of CaFeOx after the switching behavior. This study not only reveals the switching mechanism of CaFeOx , but also provides a PV oxide option for the dielectric material in resistive random-access memory (RRAM) devices.
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BACKGROUND: We used the results of a contact behavior survey in conjunction with droplet pattern measurement to investigate the indoor population transmission dynamics of respiratory infections. METHODS: A total of 404 questionnaires on all contact behaviors were distributed to junior high school students. Droplet number concentration and size distribution generated by coughing and talking were measured by droplet experimentation. A deterministic susceptible-exposed-infected-recovery (SEIR) model was used to simulate the indoor transmission dynamics of influenza infection among schoolchildren. RESULTS: Results indicated that the average contact rates ranged from 9.44 to 11.18 person(-1) day(-1) for grades 7 to 9. We showed that total median droplet number concentrations were 9.01 × 10(7) and 8.23 × 10(7) droplets per cubic meter for coughing and talking, respectively. Population dynamic simulations indicated that the size-dependent median number of droplets per person resulted in a maximum of 8 and 10 infected persons on day 4, respectively, for talking and coughing activities. CONCLUSIONS: Human contact behavior and airborne droplet characteristics may substantially change predicted indoor population transmission dynamics of influenza infection.
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Microbiología del Aire , Contaminación del Aire Interior/análisis , Trazado de Contacto , Gripe Humana/transmisión , Modelos Biológicos , Adolescente , Adulto , Niño , Preescolar , Tos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Habla , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Mozart's Sonata for two pianos in D major, K.448 (Mozart K.448), has been shown to improve mental function, leading to what is known as the Mozart effect. Our previous work revealed that epileptiform discharges in children with epilepsy decreased during and immediately after listening to Mozart K.448. In this study, we evaluated the long-term effects of Mozart K.448 on children with refractory epilepsy. Eleven children with refractory epilepsy were enrolled. All of the patients were diagnosed as having had refractory epilepsy for more than 1 year (range =1 year to 6 years 4 months, mean =3 years 11 months) and had been receiving at least two antiepileptic drugs (AED). During the study period, they listened to Mozart K.448 once a day before bedtime for 6 months. Seizure frequencies were recorded 6 months before they started listening to this music and monthly during the study period. All of the patients remained on the same AEDs during the 6-month study period. Frequencies of seizures were compared before and after listening to Mozart K.448. Eight of eleven patients were seizure free (N=2) or had very good responses (N=6) after 6 months of listening to Mozart K.448. The remaining three (27.3%) showed minimal or no effect (effectiveness <50%; unmodified or worsened seizure frequency). The average seizure reduction was 53.6 ± 62.0%. There were no significant differences in seizure reduction with IQ, etiology, or gender. We conclude that Mozart K.448 should be further studied as a potential add-on therapy in the treatment of children with refractory epilepsy.
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Epilepsia/terapia , Musicoterapia/métodos , Resultado del Tratamiento , Estimulación Acústica/métodos , Análisis de Varianza , Anticonvulsivantes/uso terapéutico , Percepción Auditiva/fisiología , Niño , Preescolar , Femenino , Humanos , Lactante , Pruebas de Inteligencia , MasculinoRESUMEN
BACKGROUND: Limb-girdle muscular dystrophy (LGMD) is a genetically heterogeneous, hereditary disease characterized by limb-girdle weakness and histologically dystrophic changes. The prevalence of each subtype of LGMD varies among different ethnic populations. This study for the first time analyzed the phenotypes and genotypes in Taiwanese patients with LGMD in a referral center for neuromuscular diseases (NMDs). RESULTS: We enrolled 102 patients clinically suspected of having LGMD who underwent muscle biopsy with subsequent genetic analysis in the previous 10 years. On the basis of different pathological categories, we performed sequencing of target genes or panel for NMDs and then identified patients with type 1B, 1E, 2A, 2B, 2D, 2I, 2G, 2 N, and 2Q. The 1B patients with LMNA mutation presented with mild limb-girdle weakness but no conduction defect at the time. All 1E patients with DES mutation exhibited predominantly proximal weakness along with distal weakness. In our cohort, 2B and 2I were the most frequent forms of LGMD; several common or founder mutations were identified, including c.1097_1099delACA (p.Asn366del) in DES, homozygous c.101G > T (p.Arg34Leu) in SGCA, homozygous c.26_33dup (p.Glu12Argfs*20) in TCAP, c.545A > G (p.Tyr182Cys), and c.948delC (p.Cys317Alafs*111) in FKRP. Clinically, the prevalence of dilated cardiomyopathy in our patients with LGMD2I aged > 18 years was 100%, much higher than that in European cohorts. The only patient with LGMD2Q with PLEC mutation did not exhibit skin lesions or gastrointestinal abnormalities but had mild facial weakness. Muscle imaging of LGMD1E and 2G revealed a more uniform involvement than did other LGMD types. CONCLUSION: Our study revealed that detailed clinical manifestation together with muscle pathology and imaging remain critical in guiding further molecular analyses and are crucial for establishing genotype-phenotype correlations. We also determined the common mutations and prevalence for different subtypes of LGMD in our cohort, which could be useful when providing specific care and personalized therapy to patients with LGMD.
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Distrofia Muscular de Cinturas , Estudios de Cohortes , Pruebas Genéticas , Humanos , Distrofia Muscular de Cinturas/genética , Mutación/genética , Pentosiltransferasa , FenotipoRESUMEN
In the developing hypothalamus, the fat-derived hormone leptin stimulates the growth of axons from the arcuate nucleus of the hypothalamus (ARH) to other regions that control energy balance. These projections are significantly reduced in leptin deficient (Lepob/ob ) mice and this phenotype is largely rescued by neonatal leptin treatments. However, treatment of mature Lepob/ob mice is ineffective, suggesting that the trophic action of leptin is limited to a developmental critical period. To temporally delineate closure of this critical period for leptin-stimulated growth, we treated Lepob/ob mice with exogenous leptin during a variety of discrete time periods, and measured the density of Agouti-Related Peptide (AgRP) containing projections from the ARH to the ventral part of the dorsomedial nucleus of the hypothalamus (DMHv), and to the medial parvocellular part of the paraventricular nucleus (PVHmp). The results indicate that leptin loses its neurotrophic potential at or near postnatal day 28. The duration of leptin exposure appears to be important, with 9- or 11-day treatments found to be more effective than shorter (5-day) treatments. Furthermore, leptin treatment for 9 days or more was sufficient to restore AgRP innervation to both the PVHmp and DMHv in Lepob/ob females, but only to the DMHv in Lepob/ob males. Together, these findings reveal that the trophic actions of leptin are contingent upon timing and duration of leptin exposure, display both target and sex specificity, and that modulation of leptin-dependent circuit formation by each of these factors may carry enduring consequences for feeding behavior, metabolism, and obesity risk.
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Proteína Relacionada con Agouti/metabolismo , Núcleo Arqueado del Hipotálamo/citología , Leptina/metabolismo , Leptina/farmacología , Neuronas/efectos de los fármacos , Factores de Edad , Análisis de Varianza , Animales , Animales Recién Nacidos , Axones/efectos de los fármacos , Proteína 3 Similar a ELAV/metabolismo , Receptor alfa de Estrógeno/metabolismo , Femenino , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Integrasas/genética , Integrasas/metabolismo , Leptina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuropéptido Y/genética , Neuropéptido Y/metabolismo , Receptores de Leptina/genética , Receptores de Leptina/metabolismo , Factor de Transcripción STAT3/metabolismoRESUMEN
The autosomal recessive limb-girdle muscular dystrophy type 2A (LGMD2A) is caused by mutations in the calpain 3 (CAPN3) gene, and it is characterized by selective atrophy and weakness of proximal limb and girdle muscles. We report a 33-year-old woman with initial presentations of exercise intolerance and running difficulty at age 15 years. At presentation, waddling gait, positive Gowers' sign, and marked muscle atrophy in pelvic and leg muscles were noted. Muscle computed tomography (CT) imaging demonstrated symmetric involvement of the posterior thigh muscles with relative sparing of vastus lateralis, sartorius, and gracilis. Muscle biopsy revealed a dystrophic change and many lobulated fibers on NADH-tetrazolium reductase staining. Genetic analysis of the CAPN3 gene identified a novel homozygous mutation of c2047_2050 del4, p.Lys683fs mutation, confirming the first LGMD2A patient in Taiwan.
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Calpaína/genética , Proteínas Musculares/genética , Distrofia Muscular de Cinturas/genética , Mutación , Adulto , Femenino , Humanos , TaiwánRESUMEN
OBJECTIVE: Brain-derived neurotrophic factor (BDNF) is a potent regulator of neuronal development, and the Bdnf gene produces two populations of transcripts with either a short or long 3' untranslated region (3' UTR). Deficiencies in BDNF signaling have been shown to cause severe obesity in humans; however, it remains unknown how BDNF signaling impacts the organization of neuronal circuits that control energy balance. METHODS: We examined the role of BDNF on survival, axonal projections, and synaptic inputs of neurons in the arcuate nucleus (ARH), a structure critical for the control of energy balance, using Bdnf (klox/klox) mice, which lack long 3' UTR Bdnf mRNA and develop severe hyperphagic obesity. RESULTS: We found that a small fraction of neurons that express the receptor for BDNF, TrkB, also expressed proopiomelanocortin (POMC) or neuropeptide Y (NPY)/agouti-related protein (AgRP) in the ARH. Bdnf(klox/klox) mice had normal numbers of POMC, NPY, and TrkB neurons in the ARH; however, retrograde labeling revealed a drastic reduction in the number of ARH axons that project to the paraventricular hypothalamus (PVH) in these mice. In addition, fewer POMC and AgRP axons were found in the dorsomedial hypothalamic nucleus (DMH) and the lateral part of PVH, respectively, in Bdnf (klox/klox) mice. Using immunohistochemistry, we examined the impact of BDNF deficiency on inputs to ARH neurons. We found that excitatory inputs onto POMC and NPY neurons were increased and decreased, respectively, in Bdnf (klox/klox) mice, likely due to a compensatory response to marked hyperphagia displayed by the mutant mice. CONCLUSION: This study shows that the majority of TrkB neurons in the ARH are distinct from known neuronal populations and that BDNF plays a critical role in directing projections from these neurons to the DMH and PVH. We propose that hyperphagic obesity due to BDNF deficiency is in part attributable to impaired axonal growth of TrkB-expressing ARH neurons.
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Botulism is a severe neuroparalytic illness which is difficult to diagnose accurately, especially in children. We report a child with type A botulism intoxication, with very rapid progression to coma-like consciousness and respiratory failure. Careful physical examinations led to the suspicion of botulism, and electrophysiologic examinations, including electroencephalogram and repetitive nerve stimulation tests, further supported the diagnosis. Hospitalization due to botulism had a great emotional impact on the patient and psychological support was crucial.
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Botulismo/complicaciones , Parálisis/microbiología , Botulismo/diagnóstico , Preescolar , Progresión de la Enfermedad , Humanos , Masculino , Insuficiencia Respiratoria/microbiologíaRESUMEN
Alpha-dystroglycanopathy is caused by the glycosylation defects of α-dystroglycan (α-DG). The clinical spectrum ranges from severe congenital muscular dystrophy (CMD) to later-onset limb girdle muscular dystrophy (LGMD). Among all α-dystroglycanopathies, LGMD type 2I caused by FKRP mutations is most commonly seen in Europe but appears to be rare in Asia. We screened uncategorized 40 LGMD and 10 CMD patients by immunohistochemistry for α-DG and found 7 with reduced α-DG immunostaining. Immunoblotting with laminin overlay assay confirmed the impaired glycosylation of α-DG. Among them, five LGMD patients harbored FKRP mutations leading to the diagnosis of LGMD2I. One common mutation, c.948delC, was identified and cardiomyopathy was found to be very common in our cohort. Muscle images showed severe involvement of gluteal muscles and posterior compartment at both thigh and calf levels, which is helpful for the differential diagnosis. Due to the higher frequency of LGMD2I with cardiomyopathy in our series, the early introduction of mutation analysis of FKRP in undiagnosed Taiwanese LGMD patients is highly recommended.
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Distroglicanos/metabolismo , Distrofia Muscular de Cinturas/epidemiología , Adolescente , Adulto , Cardiomiopatías/etiología , Cardiomiopatías/genética , Niño , Estudios de Cohortes , Análisis Mutacional de ADN , Femenino , Regulación de la Expresión Génica/genética , Humanos , Masculino , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/patología , Distrofia Muscular de Cinturas/diagnóstico , Distrofia Muscular de Cinturas/metabolismo , Pentosiltransferasa , Proteínas/genética , Radiografía , Estudios Retrospectivos , Taiwán/epidemiología , Tomógrafos Computarizados por Rayos X , Adulto JovenRESUMEN
Dystrophinopathy is caused by mutations in the dystrophin gene at Xp21. Although manifesting carriers of dystrophinopathy have been documented in adults, symptomatic dystrophinopathy in female children is rare. We report on a 13-year-old girl with initial presentation of myalgia at age 7 years and an incidental finding of increased transaminases and creatine kinase at regular health check at age 12 years. At age 13 years, manual muscle testing revealed asymmetric bilateral proximal weakness of extremities. Slight calf hypertrophy and winged scapulae were found. Muscle biopsy revealed a mosaic pattern in dystrophin immunostaining. Mutation analysis of the dystrophin gene revealed a novel de novo c.1150-2delA mutation. Accordingly, the patient was found to be an isolated dystrophinopathy carrier, manifesting limb-girdle pattern of muscle weakness in her childhood. This report suggests that dystrophinopathy should always be considered in female patients with sporadic myopathy. Dystrophin immunostaining and mutation analysis for the dystrophin gene are necessary for final diagnosis, subsequent genetic counseling, and long-term care.
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Creatina Quinasa/sangre , Distrofina/genética , Heterocigoto , Mialgia/etiología , Adolescente , Femenino , HumanosRESUMEN
This study aimed to evaluate muscle involvement pattern and correlate the lesions on muscle imaging with clinical features and D4Z4 fragment size in 24 patients with facioscapulohumeral muscular dystrophy (FSHD). The grading of the muscle image detected by computed tomography (CT) was based on a four-point semi-quantitative visual scale. On muscle CT, the most affected muscle was trapezium, followed by hamstrings. CT image identified hamstrings involvement rather than shoulder-girdle in clinically asymptomatic subjects. CT image also showed that axial muscle was affected in one-third of patients which appeared even earlier than clinical manifestation. Strong correlations between CT findings, serum creatine kinase level and clinical severity scores were also found. Asymmetric involvement was more evident on CT image than it identified in manual muscle strength testing. Inverse correlation between CT grade and D4Z4 fragment size was clearly demonstrated. These findings suggest muscle CT will be helpful for the process of early intervention in FSHD, even in subjects in a preclinical status.
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Cromosomas Humanos Par 4 , Músculo Esquelético/fisiopatología , Distrofia Muscular Facioescapulohumeral/genética , Fenotipo , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distrofia Muscular Facioescapulohumeral/diagnóstico , Tomografía Computarizada por Rayos X , Adulto JovenRESUMEN
Multiple organ infarctions are a very rare clinical event in children. We report a 3-month-old infant with sepsis and disseminated intravascular coagulation, who was diagnosed with cerebral ischemic stroke associated with middle cerebral artery stenosis and subsequent retinal infarction by magnetic resonance imaging, fundoscopy and magnetic resonance angiography. In addition, he suffered from renal infarction with hypertension and was treated until 1 year of age. We emphasize the importance of early recognition of organ infarctions, prophylaxis of risk factors and of optimized therapy of the underlying etiology.
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Coagulación Intravascular Diseminada/complicaciones , Infarto/diagnóstico , Sepsis/complicaciones , Humanos , Lactante , Infarto/etiología , MasculinoRESUMEN
Obesity is a potential risk factor for cognitive deficits in the elder humans. Using a high-fat diet (HFD)-induced obese mouse model, we investigated the impacts of HFD on obesity, metabolic and stress hormones, learning performance, and hippocampal synaptic plasticity. Both male and female C57BL/6J mice fed with HFD (3 weeks to 9-12 months) gained significantly more weights than the sex-specific control groups. Compared with the obese female mice, the obese males had similar energy intake but developed more weight gains. The obese male mice developed hyperglycemia, hyperinsulinemia, hypercholesterolemia, and hyperleptinemia, but not hypertriglyceridemia. The obese females had less hyperinsulinemia and hypercholesterolemia than the obese males, and no hyperglycemia and hypertriglyceridemia. In the contextual fear conditioning and step-down passive avoidance tasks, the obese male, but not female, mice showed poorer learning performance than their normal counterparts. These learning deficits were not due to sensorimotor impairment as verified by the open-field and hot-plate tests. Although, basal synaptic transmission characteristics (input-output transfer and paired-pulse facilitation (PPF) ratio) were not significantly different between normal and HFD groups, the magnitudes of synaptic plasticity (long-term potentiation (LTP) and long-term depression (LTD)) were lower at the Schaffer collateral-CA1 synapses of the hippocampal slices isolated from the obese male, but not female, mice, as compared with their sex-specific controls. Our results suggest that male mice are more vulnerable than the females to the impacts of HFD on weight gains, metabolic alterations and deficits of learning, and hippocampal synaptic plasticity.
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Trastornos del Conocimiento/etiología , Grasas de la Dieta/administración & dosificación , Hipocampo/fisiopatología , Enfermedades Metabólicas/etiología , Plasticidad Neuronal , Obesidad/complicaciones , Factores Sexuales , Animales , Reacción de Prevención , Condicionamiento Clásico , Modelos Animales de Enfermedad , Ingestión de Energía , Miedo , Femenino , Hiperglucemia/etiología , Hiperinsulinismo/etiología , Hiperlipidemias/etiología , Aprendizaje , Depresión Sináptica a Largo Plazo , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/metabolismo , Distribución Aleatoria , Transmisión Sináptica , Aumento de PesoRESUMEN
Gabapentin, a novel anticonvulsant and analgesic, is a gamma-aminobutyric acid (GABA) analogue but was shown initially to have little affinity at GABA(A) or GABA(B) receptors. It was recently reported to be a selective agonist at GABA(B) receptors containing GABA(B1a)-GABA(B2) heterodimers, although several subsequent studies disproved that conclusion. In the present study, we examined whether gabapentin is an agonist at native GABA(B) receptors using a rat model of postoperative pain in vivo and periaqueductal gray (PAG) slices in vitro; PAG contains GABA(B) receptors, and their activation results in antinociception. An intrathecal injection of gabapentin or baclofen, a GABA(B) receptor agonist, induced antiallodynia in this postoperative pain model. Intrathecal injection of GABA(B) receptor antagonists CGP 35348 and CGP 55845 antagonized baclofen- but not gabapentin-induced antiallodynia. In ventrolateral PAG neurons, baclofen activated G-protein-coupled inwardly rectifying K(+) (GIRK) channels in a manner blocked by CGP 35348 or CGP 55845. However, gabapentin displayed no effect on the membrane current. In neurons unaffected by gabapentin, baclofen activated GIRK channels through GABA(B) receptors. It is concluded that gabapentin is not an agonist at GABA(B) receptors that are functional in baclofen-induced antiallodynia in the postoperative pain model in vivo and in GIRK channel activation in ventrolateral PAG neurons in vitro.