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1.
Artigo em Inglês | MEDLINE | ID: mdl-38458374

RESUMO

OBJECTIVE: To investigate the immediate effects of plastic ankle-foot orthosis (AFO) on locomotor performance in patients with stroke and determine how such effects might undergo alteration when distinct plantarflexor (PF) module subtypes are considered. DESIGN: Cross-sectional study. SETTING: Two university hospitals. PARTICIPANTS: Fifty-two patients with stroke and 21 of those without stroke (N=73). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor modules were identified through non-negative matrix factorization, and participants were classified into 3 groups: independent-normal-timing, independent-altered-timing, and merged PF modules. To assess the effects of the AFO, gait measurements reflecting locomotor performance were obtained with and without the presence of the plastic AFO for each group. RESULTS: The independent-altered-timing group had increased paretic propulsion, greater non-paretic step length, and faster walking speed after the administration of the plastic AFO; however, these significant changes were not observed in the independent-normal-timing and merged PF module groups. Notably, patients in the independent-normal-timing and merged PF module groups exhibited longer paretic stance times. CONCLUSION: This study suggests that the immediate effects of plastic AFO depend on the PF module subtype. These findings can potentially guide clinical decision-making regarding AFO selection for stroke rehabilitation in patients with diverse gait control characteristics.

2.
Aging Clin Exp Res ; 34(12): 3033-3039, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36057083

RESUMO

AIMS: Using the reliable change index (RCI), we aimed to examine the effect of a multicomponent exercise program on the individual level. METHODS: Overall, 270 adults (mean age, 78 years) completed a multicomponent physical exercise program (strength, aerobic, gait, and balance) for 40 min, 1-2 times per week, continued up to 1 year at a daycare center. Effectiveness was assessed using grip, ankle, knee, and hip strength; Timed Up & Go (TUG); Berg Balance Scale (BBS); gait speed; and 6-min walking distance. These were measured at baseline and every 3 months thereafter. We calculated the RCI using the data between two-time points (baseline and at 3, 6, 9, or 12 months) in each participant and then calculated the mean RCI value across the participants. A paired t-test was also employed to evaluate the effect of the intervention as an average-based statistics. RESULTS: The highest mean RCI values were on ankle plantar-flexion strength, followed by gait speed, hip abduction strength, BBS, knee extensor strength, 6-min walk distance, grip strength, and finally TUG. Paired t-test also revealed significant improvement with moderate effect sizes for ankle plantar-flexion strength (0.504), gait speed (0.413), hip abduction strength (0.374), BBS (0.334), knee extensor strength (0.264), and 6-min walk distance (0.248). Significant but small effect size was seen on TUG (0.183). CONCLUSION: The RCI is a convenient method of comparing the effect between different assessments, especially at an individual level. This index can be applied to the use of personal feedback.


Assuntos
Força Muscular , Equilíbrio Postural , Humanos , Idoso , Marcha , Caminhada , Terapia por Exercício/métodos
3.
BMC Vet Res ; 13(1): 389, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29237452

RESUMO

BACKGROUND: Leucine-rich glioma-inactivated (LGI) proteins play a critical role in synaptic transmission. Dysfunction of these genes and encoded proteins is associated with neurological disorders such as genetic epilepsy or autoimmune limbic encephalitis in animals and human. Familial spontaneous epileptic cats (FSECs) are the only feline strain and animal model of familial temporal lobe epilepsy. The seizure semiology of FSECs comprises recurrent limbic seizures with or without evolution into generalized epileptic seizures, while cats with antibodies against voltage-gated potassium channel complexed/LGI1 show limbic encephalitis and recurrent limbic seizures. However, it remains unclear whether the genetics underlying FSECs are associated with LGI family genes. In the present study, we cloned and characterized the feline LGI1-4 genes and examined their association with FSECs. Conventional PCR techniques were performed for cloning and mutational analysis. Characterization was predicted using bioinformatics software. RESULTS: The cDNAs of feline LGI1-4 contained 1674-bp, 1650-bp, 1647-bp, and 1617-bp open reading frames, respectively, and encoded proteins comprising 557, 549, 548, and 538 amino acid residues, respectively. The feline LGI1-4 putative protein sequences showed high homology with Homo sapiens, Canis familiaris, Bos taurus, Sus scrofa, and Equus caballus (92%-100%). Mutational analysis in 8 FSECs and 8 controls for LGI family genes revealed 3 non-synonymous and 14 synonymous single nucleotide polymorphisms in the coding region. Only one non-synonymous single nucleotide polymorphism in LGI4 was found in 3 out of 8 FSECs. Using three separate computational tools, this mutation was not predicted to be disease causing. No co-segregation of the disease was found with any variant. CONCLUSIONS: We cloned the cDNAs of the four feline LGI genes, analyzed the amino acid sequences, and revealed that epilepsy in FSEC is not a monogenic disorder associated with LGI genes.


Assuntos
Doenças do Gato/genética , Síndromes Epilépticas/veterinária , Animais , Gatos/genética , Clonagem Molecular/métodos , Análise Mutacional de DNA/veterinária , Síndromes Epilépticas/genética , Feminino , Genes/genética , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
4.
BMC Vet Res ; 12(1): 248, 2016 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-27829458

RESUMO

BACKGROUND: Epilepsy is the most common neurological disease in veterinary practice. However, contrary to human medicine, epilepsy classification in veterinary medicine had not been clearly defined until recently. A number of reports on canine epilepsy have been published, reflecting in part updated proposals from the human epilepsy organization, the International League Against Epilepsy. In 2015, the International Veterinary Epilepsy Task Force (IVETF) published a consensus report on the classification and definition of canine epilepsy. The purpose of this retrospective study was to investigate the etiological distribution, survival time of dogs with idiopathic epilepsy (IdE) and structural epilepsy (StE), and risk factors for survival time, according to the recently published IVETF classification. We investigated canine cases with epilepsy that were referred to our teaching hospital in Japan during the past 10 years, and which encompassed a different breed population from Western countries. RESULTS: A total of 358 dogs with epilepsy satisfied our etiological study criteria. Of these, 172 dogs (48 %) were classified as IdE and 76 dogs (21 %) as StE. Of these dogs, 100 dogs (consisting of 65 with IdE and 35 with StE) were included in our survival study. Median survival time from the initial epileptic seizure in dogs with IdE and StE was 10.4 and 4.5 years, respectively. Median lifespan of dogs with IdE and StE was 13.5 and 10.9 years, respectively. Multivariable analysis demonstrated that risk factors for survival time in IdE were high seizure frequency (≥0.3 seizures/month) and focal epileptic seizures. CONCLUSIONS: Focal epileptic seizures were identified as a risk factor for survival time in IdE. Clinicians should carefully differentiate seizure type as it is difficult to identify focal epileptic seizures. With good seizure control, dogs with IdE can survive for nearly the same lifespan as the general dog population. Our results using the IVETF classification are similar to previous studies, although some features were noted in our Japanese canine population (which was composed of mainly small-breed dogs), including a longer lifespan in dogs with epilepsy and a larger percentage of meningoencephalomyelitis of unknown origin in dogs with StE.


Assuntos
Doenças do Cão/epidemiologia , Epilepsia/veterinária , Animais , Cães , Epilepsia/epidemiologia , Feminino , Japão/epidemiologia , Expectativa de Vida , Masculino , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida
5.
Cortex ; 169: 203-219, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37948875

RESUMO

Color has meaning in particular contexts, and the meaning of color can impact behavioral performance. For example, the meaning of color about traffic rules (blue/green and red mean "go" and "stop" respectively) influences reaction times (RTs) to signals. Specifically, in a Go/No-go task, RTs have been reported to be longer when responding to a red signal and withholding the response to a blue signal (Red Go/Blue No-go task) than when responding to a blue signal and withholding the response to a red signal (Blue Go/Red No-go task). However, the neurophysiological background of this phenomenon has not been fully understood. The purpose of this study was to investigate the brain oscillatory activity associated with the effect of meaning of color on RTs in the Go/No-go task. Twenty participants performed a Blue simple reaction task, a Red simple reaction task, a Blue Go/Red No-go task, and a Red Go/Blue No-go task. We recorded responses to signals and electroencephalogram (EEG) during the tasks and evaluated RTs and changes in spectral power over time, referred to as event-related synchronization (ERS) and event-related desynchronization (ERD). The behavioral results were similar to previous studies. The EEG results showed that frontal beta ERD and theta ERS were greater when signals were presented in blue than red color in both simple reaction and Go/No-go tasks. In addition, the onset of theta ERS was delayed in the Red Go than Blue Go trial in the Go/No-go task. The enhanced beta ERD may indicate that blue signals facilitate motor response, and the delayed onset of theta ERS may indicate the delayed onset of cognitive process when responding to red signals as compared to blue signals in the Go/No-go task. Thus, this delay in cognitive process can be involved in the slow response in the Red Go/Blue No-go task.


Assuntos
Encéfalo , Eletroencefalografia , Humanos , Tempo de Reação/fisiologia , Encéfalo/fisiologia , Sincronização Cortical/fisiologia
6.
ScientificWorldJournal ; 2012: 250197, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22536126

RESUMO

GM1 gangliosidosis is a fatal neurodegenerative lysosomal storage disease caused by an autosomal recessively inherited deficiency of ß-galactosidase activity. Effective therapies need to be developed to treat the disease. In Shiba Inu dogs, one of the canine GM1 gangliosidosis models, neurological signs of the disease, including ataxia, start at approximately 5 months of age and progress until the terminal stage at 12 to 15 months of age. In the present study, serial MR images were taken of an affected dog from a model colony of GM1 gangliosidosis and 4 sporadic clinical cases demonstrating the same mutation in order to characterize the MRI features of this canine GM1 gangliosidosis. By 2 months of age at the latest and persisting until the terminal stage of the disease, the MR findings consistently displayed diffuse hyperintensity in the white matter of the entire cerebrum on T2-weighted images. In addition, brain atrophy manifested at 9 months of age and progressed thereafter. Although a definitive diagnosis depends on biochemical and genetic analyses, these MR characteristics could serve as a diagnostic marker in suspect animals with or without neurological signs. Furthermore, serial changes in MR images could be used as a biomarker to noninvasively monitor the efficacy of newly developed therapeutic strategies.


Assuntos
Biomarcadores , Doenças do Cão/diagnóstico , Gangliosidose GM1/veterinária , Imageamento por Ressonância Magnética/métodos , Animais , Progressão da Doença , Doenças do Cão/patologia , Cães , Gangliosidose GM1/diagnóstico , Gangliosidose GM1/patologia , Masculino
7.
Heliyon ; 8(5): e09469, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35647346

RESUMO

Prior knowledge of color, such as traffic rules (blue/green and red mean "go" and "stop" respectively), can influence reaction times (RTs). Specifically, in a Go/No-go task, where signals were presented by a light-emitting diode (LED) lighting device, RT has been reported to be longer when responding to a red signal and withholding the response to a blue signal (Red Go/Blue No-go task) than when responding to a blue signal and withholding the response to a red signal (Blue Go/Red No-go task). In recent years, a driving simulator has been shown to be effective in evaluation and training of driving skills of dementia and stroke patients. However, it is unknown whether the change in RT observed with the LED lighting device can be replicated with a monitor presenting signals that are different from the real traffic lights in terms of depth and texture. The purpose of this study was to elucidate whether a difference in visual modality (LED and monitor) influences the effect of prior knowledge of color on RTs. Fifteen participants performed a simple reaction task (Blue and Red signals), a Blue Go/Red No-go task, and a Red Go/Blue No-go task. Signals were presented from an LED lighting device (Light condition) and a liquid crystal display (LCD) monitor (Monitor condition). The results showed that there was no significant difference in simple RT by signal color in both conditions. In the Go/No-go task, there was a significant interaction between the type of signal presentation device and the color of signal. Although the RT was significantly longer in the Red Go/Blue No-go than Blue Go/Red No-go task in the Light condition, there was no significant difference in RT between the Blue Go/Red No-go and Red Go/Blue No-go tasks in the Monitor condition. It is interpreted that blue and red signals presented from the LCD monitor were insufficient to evoke a perception of traffic lights as compared to the LED. This study suggests that a difference in the presentation modality (LED and monitor) of visual information can influence the level of object perception and consequently the effect of prior knowledge on behavioral responses.

8.
PLoS One ; 17(12): e0279477, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36548285

RESUMO

During submaximal isometric contraction, there are two different load types: maintenance of a constant limb angle while supporting an inertial load (position task) and maintenance of a constant force by pushing against a rigid restraint (force task). Previous studies demonstrated that performing the position task requires more proprioceptive information. The purpose of this study was to investigate whether there would be a difference in cutaneous information processing between the position and force tasks by assessing the gating effect, which is reduction of amplitude of somatosensory evoked potentials (SEPs), and cutaneomuscular reflex (CMR). Eighteen healthy adults participated in this study. They contracted their right first dorsal interosseous muscle by abducting their index finger to produce a constant force against a rigid restraint that was 20% maximum voluntary contraction (force task), or to maintain a target position corresponding to 10° abduction of the metacarpophalangeal joint while supporting a load equivalent to 20% maximum voluntary contraction (position task). During each task, electrical stimulation was applied to the digital nerves of the right index finger, and SEPs and CMR were recorded from C3' of the International 10-20 system and the right first dorsal interosseous muscle, respectively. Reduction of the amplitude of N33 component of SEPs was significantly larger during the force than position task. In addition, the E2 amplitude of CMR was significantly greater for the force than position task. These findings suggest that cutaneous information processing differs with load type during static muscle contraction.


Assuntos
Dedos , Músculo Esquelético , Adulto , Humanos , Músculo Esquelético/fisiologia , Dedos/fisiologia , Contração Muscular/fisiologia , Reflexo/fisiologia , Pele/inervação , Contração Isométrica/fisiologia , Eletromiografia
9.
Geriatr Gerontol Int ; 22(3): 213-218, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35080094

RESUMO

AIM: To clarify the difference in the longitudinal effects of physical exercise on health-related outcomes according to the baseline frailty status (frail or non-frail) in community-dwelling older adults. METHODS: Participants included 177 adults aged ≥65 years who carried out multicomponent physical exercises (strength, aerobic, gait and balance) for 40 min, one to three times per week, for 1 year at a day-care center. Bodyweight, comfortable walking speed, 6-min walking distance and Mini-Mental State Examination were measured at baseline and every 3 months. For longitudinal trend, we analyzed the change in scores from baseline for each outcome using the linear mixed effects model. Fixed effects included "group" (frail or non-frail), "time" (4 time points every 3 months, from 3 to 12 months) and "interaction between group and time." RESULTS: The effect sizes from baseline showed almost all positive values for each outcome. The linear mixed effects model showed significant effects on "interaction between group and time" in changes in bodyweight (P = 0.033), "group" in changes in walking speed (P = 0.013) and "time" in changes in the Mini-Mental State Examination (P < 0.001). Bodyweight showed a decreasing trend in the non-frail group after 3 months, unlike in the frail group. For walking speed, moderate effect sizes (d = 0.67-0.74) were sustained over time in the frail group, as did lesser effect sizes (d = 0.26-0.40) in the non-frail group. CONCLUSIONS: Exercise-based multicomponent interventions were effective for both groups. The longitudinal effects on walking speed and bodyweight were greater in the frail group. Geriatr Gerontol Int 2022; 22: 213-218.


Assuntos
Fragilidade , Idoso , Exercício Físico , Terapia por Exercício , Idoso Fragilizado , Avaliação Geriátrica , Humanos , Vida Independente
10.
Front Hum Neurosci ; 15: 674964, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177494

RESUMO

In daily life, the meaning of color plays an important role in execution and inhibition of a motor response. For example, the symbolism of traffic light can help pedestrians and drivers to control their behavior, with the color green/blue meaning go and red meaning stop. However, we don't always stop with a red light and sometimes start a movement with it in such a situation as drivers start pressing the brake pedal when a traffic light turns red. In this regard, we investigated how the prior knowledge of traffic light signals impacts reaction times (RTs) and event-related potentials (ERPs) in a Go/No-go task. We set up Blue Go/Red No-go and Red Go/Blue No-go tasks with three different go signal (Go) probabilities (30, 50, and 70%), resulting in six different conditions. The participants were told which color to respond (Blue or Red) just before each condition session but didn't know the Go probability. Neural responses to Go and No-go signals were recorded at Fz, Cz, and Oz (international 10-20 system). We computed RTs for Go signal and N2 and P3 amplitudes from the ERP data. We found that RT was faster when responding to blue than red light signal and also was slower with lower Go probability. Overall, N2 amplitude was larger in Red Go than Blue Go trial and in Red No-go than Blue No-go trial. Furthermore, P3 amplitude was larger in Red No-go than Blue No-go trial. Our findings of RT and N2 amplitude for Go ERPs could indicate the presence of Stroop-like interference, that is a conflict between prior knowledge about traffic light signals and the meaning of presented signal. Meanwhile, the larger N2 and P3 amplitudes in Red No-go trial as compared to Blue No-go trial may be due to years of experience in stopping an action in response to a red signal and/or attention. This study provides the better understanding of the effect of prior knowledge of color on behavioral responses and its underlying neural mechanisms.

11.
Front Hum Neurosci ; 15: 617146, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679346

RESUMO

INTRODUCTION: Previous transcranial magnetic stimulation (TMS) studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand (ipsi-M1) plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements. METHOD: Ten healthy right-handed subjects performed four finger tapping tasks with the index finger: (1) simple tapping (Tap) task, (2) Real-word task, (3) Pseudoword task, and (4) Visually guided tapping (VT) task. In the Tap task, the subject performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word (e.g., apple). Because the action had a specific purpose (i.e., creating a word), this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword (e.g., gdiok) in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition (SICI and LICI) in the resting first dorsal interosseous (FDI) muscle. RESULTS: We found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions. DISCUSSION: We found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis.

13.
Front Vet Sci ; 8: 719455, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34355038

RESUMO

Epilepsy surgery is a common therapeutic option in humans with drug-resistant epilepsy. However, there are few reports of intracranial epilepsy surgery for naturally occurring epilepsy in veterinary medicine. A 12-year-old neutered male domestic shorthair cat with presumed congenital cortical abnormalities (atrophy) in the right temporo-occipital cortex and hippocampus had been affected with epilepsy from 3 months of age. In addition to recurrent epileptic seizures, the cat exhibited cognitive dysfunction, bilateral blindness, and right forebrain signs. Seizures had been partially controlled (approximately 0.3-0.7 seizures per month) by phenobarbital, zonisamide, diazepam, and gabapentin until 10 years of age; however, they gradually became uncontrollable (approximately 2-3 seizures per month). In order to plan epilepsy surgery, presurgical evaluations including advanced structural magnetic resonance imaging and long-term intracranial video-electroencephalography monitoring were conducted to identify the epileptogenic zone. The epileptogenic zone was suspected in the right atrophied temporo-occipital cortex and hippocampus. Two-step surgery was planned, and a focal cortical resection of that area was performed initially. After the first surgery, seizures were not observed for 2 months, but they then recurred. The second surgery was performed to remove the right atrophic hippocampus and extended area of the right cortex, which showed spikes on intraoperative electrocorticography. After the second operation, although epileptogenic spikes remained in the contralateral occipital lobe, which was suspected as the second epileptogenic focus, seizure frequency decreased to <0.3 seizure per month under treatment with antiseizure drugs at 1.5 years after surgery. There were no apparent complications associated with either operation, although the original neurological signs were unchanged. This is the first exploratory study of intracranial epilepsy surgery for naturally occurring epilepsy, with modern electroclinical and imaging evidence, in veterinary medicine. Along with the spread of advanced diagnostic modalities and neurosurgical devices in veterinary medicine, epilepsy surgery may be an alternative treatment option for drug-resistant epilepsy in cats.

15.
Brain Sci ; 11(6)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199505

RESUMO

Transcranial static magnetic field stimulation (tSMS) can modulate human cortical excitability and behavior. To better understand the neuromodulatory effect of tSMS, this study investigates whether tSMS applied over the left dorsolateral prefrontal cortex (DLPFC) modulates working memory (WM) performance and its associated event-related potentials (ERPs). Thirteen healthy participants received tSMS or sham stimulation over the left DLPFC for 26 min on different days. The participants performed a 2-back version of the n-back task before, during (20 min after the start of stimulation), immediately after, and 15 min after the stimulation. We examine reaction time for correct responses, d-prime reflecting WM performance, and the N2 and P3 components of ERPs. Our results show that there was no effect of tSMS on reaction time. The d-prime was reduced, and the N2 latency was prolonged immediately after tSMS. These findings indicate that tSMS over the left DLPFC affects WM performance and its associated electrophysiological signals, which can be considered an important step toward a greater understanding of tSMS and its use in studies of higher-order cognitive processes.

16.
Brain Sci ; 11(4)2021 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-33920398

RESUMO

The purpose of this pilot study was to investigate whether transcranial static magnetic field stimulation (tSMS), which can modulate cortical excitability, would influence inhibitory control function when applied over the dorsolateral prefrontal cortex (DLPFC). Young healthy adults (n = 8, mean age ± SD = 24.4 ± 4.1, six females) received the following stimulations for 30 min on different days: (1) tSMS over the left DLPFC, (2) tSMS over the right DLPFC, and (3) sham stimulation over either the left or right DLPFC. The participants performed a Go/NoGo task before, immediately after, and 10 min after the stimulation. They were instructed to extend the right wrist in response to target stimuli. We recorded the electromyogram from the right wrist extensor muscles and analyzed erroneous responses (false alarm and missed target detection) and reaction times. As a result, 50% of the participants made erroneous responses, and there were five erroneous responses in total (0.003%). A series of statistical analyses revealed that tSMS did not affect the reaction time. These preliminary findings suggest the possibility that tSMS over the DLPFC is incapable of modulating inhibitory control and/or that the cognitive load imposed in this study was insufficient to detect the effect.

17.
Chem Commun (Camb) ; 55(83): 12491-12494, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31573004

RESUMO

Photoelectrochemical oxidation of thiols was enhanced with a threshold potential of -0.35 V vs. Ag/AgCl by the use of a ZnPc/PCBM:P3HT/ZnO electode, which was prepared by removing the PEDOT:PSS/Au electrode of an inverted OPV device and coating it with ZnPc. A co-photocatalysis property of ZnPc was observed in the photoelectrochemistry and scanning Kelvin probe microscopy.

18.
Biochim Biophys Acta ; 1767(6): 660-5, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17187754

RESUMO

Adsorption of [(OH(2))(terpy)Mn(mu-O)(2)Mn(terpy)(OH(2))](3+) (terpy=2,2':6',2"-terpyridine) (1) onto montmorillonite K10 (MK10) yielded catalytic dioxygen (O(2)) evolution from water using a Ce(IV) oxidant. The Mn K-edge X-ray absorption near edge structure (XANES) of the 1/MK10 hybrid suggested that the oxidation state of the di-mu-oxo Mn(2) core could be Mn(III)-Mn(IV). However the pre-edge peak in the XANES spectrum of 1 adsorbed on MK10 is different from the neat 1 powder. The kinetic analysis of O(2) evolution showed that the catalysis requires cooperation of two equivalents of 1 adsorbed on MK10. The reaction of the [(bpy)(2)Mn(mu-O)(2)Mn(bpy)(2)](3+) (bpy=2,2'-bipyridine) (2)/MK10 hybrid with a Ce(IV) oxidant evolved O(2). However, the turnover number value was less than unity for 2/MK10, showing that 2 adsorbed on MK10 does not work as a catalyst. The terminal water ligands could be an important for the catalysis by adsorbed 1. The mechanism of O(2) production by photosynthetic oxygen evolving complex is discussed based on catalytic O(2) evolution by 1 adsorbed on MK10.


Assuntos
Silicatos de Alumínio/química , Bentonita/farmacocinética , Manganês/química , Modelos Biológicos , Oxigênio/química , Água/química , Adsorção , Catálise , Argila , Dimerização , Cinética , Compostos Organometálicos/química , Oxirredução , Oxigênio/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema II
19.
J Feline Med Surg ; 10(4): 418-21, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18372205

RESUMO

With the eventual goal of making zonisamide (ZNS), a relatively new antiepileptic drug, available for the treatment of epilepsy in cats, the pharmacokinetics after a single oral administration at 10mg/kg and the toxicity after 9-week daily administration of 20mg/kg/day of ZNS were studied in healthy cats. Pharmacokinetic parameters obtained with a single administration of ZNS at 10mg/day were as follows: Cmax=13.1microg/ml; Tmax=4.0h; T(1/2)=33.0h; areas under the curves (AUCs)=720.3microg/mlh (values represent the medians). The study with daily administrations revealed that the toxicity of ZNS was comparatively low in cats, suggesting that it may be an available drug for cats. However, half of the cats that were administered 20mg/kg/day daily showed adverse reactions such as anorexia, diarrhoea, vomiting, somnolence and locomotor ataxia.


Assuntos
Anticonvulsivantes/farmacocinética , Doenças do Gato/induzido quimicamente , Gatos/metabolismo , Isoxazóis/farmacocinética , Administração Oral , Animais , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/toxicidade , Área Sob a Curva , Disponibilidade Biológica , Doenças do Gato/sangue , Gatos/sangue , Relação Dose-Resposta a Droga , Feminino , Isoxazóis/efeitos adversos , Isoxazóis/toxicidade , Masculino , Taxa de Depuração Metabólica , Zonisamida
20.
ACS Omega ; 3(5): 5678-5684, 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458767

RESUMO

The molecular orientation of organic molecules of zinc phthalocyanine (ZnPc) in single-component films on copper iodide (CuI) substrates can be controlled to achieve a molecular orientation lying flat on the substrate (flat-on) owing to π-d orbital interactions between the ZnPc molecules and the CuI. A 3-fold enhancement in the performance of organic photovoltaic cells has been reported by introducing a CuI interlayer between a ZnPc:fullerene (C60) bulk heterojunction (BHJ) film and the substrate. However, the mechanism underpinning the resultant solar cell performance enhancement was unclear. Herein, we report on the results of using in situ reflection absorption spectroscopy measurements during the vacuum deposition of coevaporated ZnPc:C60 BHJ films on various substrates to investigate the ZnPc molecular orientation. Our results revealed that the flat-on molecular orientation of ZnPc molecules in ZnPc:C60 BHJ films on CuI interlayers and flat-on ZnPc substrates can be successfully identified via the strong π-π interactions between the BHJ film and the substrate. The π-π interactions between individual ZnPc molecules are stronger than the π-d interactions between ZnPc molecules and CuI in coevaporated ZnPc:C60 films, as is evident from the molecular orientation of ZnPc, as determined by in situ reflection absorption spectroscopy. Our findings demonstrate that precisely controlling the molecular orientations of the films could enhance organic photovoltaic (OPV) performance. The present work provides important insights that will enable the design of higher performance OPV cells.

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