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1.
Sci Total Environ ; : 174907, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39034008

RESUMO

Microplastics (MPs) are omnipresent in the environment and they are linked to ecosystem and human health problems. The atmospheric transport of MPs and the role of tree leaves in MP atmospheric deposition has not been adequately studied. MP concentrations on the leaves of different tree species in urban regions of the Netherlands and Portugal, along with related MP deposition, were investigated in this study. We collected leaves from cedar, eucalyptus, oak, pine and willow trees, together with monthly deposition of particles under the trees and in the open space in Coimbra (Portugal). In Wageningen (the Netherlands), we collected leaves from a fir and a holly tree at different heights above the ground and with dry and wet weather conditions. MPs were extracted through density separation and quantified under a microscope. Polymer types were identified using µ-FTIR. The results showed a higher number of MP particles on the needle-shaped leaves from fir (2.52 ±â€¯2.14 particles·cm-2) and pine (0.5 ±â€¯0.13 particles·cm-2) and significantly lower numbers of MPs per cm2 of leaf area on the bigger leaves from eucalyptus (0.038 ±â€¯0.003 particles·cm-2) and cedar (0.037 ±â€¯0.002 particles·cm-2). All tree leaves seemed to filter airborne MPs, especially the smallest particles. A non-significantly higher number of particles on leaves was detected on lower tree branches and after dry periods. The deposition of MPs under trees was generally higher than in the open space. Our results indicated that part of the MPs retained by the tree leaves floats down to lower branches and to the soil surface. We also saw that different tree species had different capacities to retain particles on their leaves over time. To control the transport of MPs through the atmosphere, it is essential to consider the role of different vegetation types in filtering small particles, especially in cities.

2.
Occup Med (Lond) ; 70(9): 680-684, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33247305

RESUMO

BACKGROUND: The number of patients living with depression continues to increase in Japan. The economic effects of depression include loss of productivity due to both absenteeism and presenteeism. Gender differences have been reported in prevalence, onset pathways and subjective symptoms of depression. AIMS: To understand how workers with major depressive disorder (MDD) perceive problems in the workplace and examine gender differences in their self-perceived levels of functioning at work, noticed during the initial stages of depression. METHODS: This is a cross-sectional study of Japanese workers with MDD. Participants' self-perceived changes in the level of functioning at work were surveyed after the diagnosis during the first visit. The relationship between gender and changes in the level of functioning at work as initially perceived by the participants themselves was analysed using the chi-square test, supplemented by a residual analysis. RESULTS: We administered the survey to 147 workers with MDD. In terms of gender differences in initial self-perceived changes in the level of functioning at work, the proportion of men reporting reduced work efficiency was significantly higher than that of women, while the proportion of women reporting deterioration in relationships with colleagues and superiors was significantly higher than that of men. CONCLUSIONS: The findings suggest that greater attention to reduced work efficiency by men and to deterioration in work relationships by women with MDD should be essential components of self-care. Managers need to pay attention to the level of functioning and provide adequate social support for employees.


Assuntos
Depressão , Transtorno Depressivo Maior , Absenteísmo , Estudos Transversais , Feminino , Humanos , Japão , Masculino , Caracteres Sexuais , Inquéritos e Questionários , Local de Trabalho
3.
Sci Rep ; 9(1): 9803, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31278289

RESUMO

The anthropogenic CO2 accumulating in the ocean is lowering seawater carbonate ion concentration and may reduce calcification rates of marine calcareous organisms. Several proxies based on test weights of planktic foraminifera have been used to evaluate the impact of ocean acidification on these organisms. Unfortunately, because of the absence of a method to evaluate the bulk density of a test, the impact of seawater carbonate chemistry on test calcification is still not fully understood. In this study, we measured bulk densities of living Globigerina bulloides (planktic foraminifera) tests with an X-ray micro-computed tomography (XMCT) scanner and compared them with ambient seawater characteristics. Results demonstrated that test bulk densities were controlled by ambient seawater carbonate ion concentrations and that changes of test bulk densities were accompanied by changes in micron to submicron scale porosity of internal ultrastructure. These results suggest that alteration of the bulk density of foraminiferal tests due to acidification of ambient seawater can be directly observed by XMCT scanning. A useful metric of calcification intensity would therefore be physical measurements of test densities with XMCT.


Assuntos
Calcificação Fisiológica , Foraminíferos/fisiologia , Oceanos e Mares , Plâncton/fisiologia , Água do Mar/química , Carbonato de Cálcio/química , Ciclo do Carbono/fisiologia , Dióxido de Carbono/química , Carbonatos/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Microtomografia por Raio-X
4.
Occup Med (Lond) ; 69(1): 39-46, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30428079

RESUMO

BACKGROUND: Teaching is one of the most stressful occupations. Over the last decade, about 5000 Japanese public school teachers per year have taken sick leave due to a mental illness. School principals and vice principals also face occupational stress, although few studies have examined occupational stress in these groups. AIMS: To clarify the relationship between occupational stress, role problems and depressive symptoms among school principals and vice principals in Japan. METHODS: We conducted a cross-sectional study in 2013 with data from 262 principals and 268 vice principals in Japan. We used the Japanese version of Zung's Self-Rating Depression Scale (SDS) to evaluate depressive symptoms and the Generic Job Stress Questionnaire to evaluate occupational stress and social support. We categorized SDS scores above 49 as indicating depression. We examined the relationship between depressive symptoms and perceived occupational stress using stepwise forward multivariate logistic regression analyses. RESULTS: Thirty-six (14%) principals and 81 (30%) vice-principals were categorized into the depressive group. Quantitative workload (odds ratio, OR = 6.62 [2.63-16.70]) and role ambiguity (OR = 4.94[1.57-15.53]) were associated with higher depressive scores in principals. Social support from supervisors (OR = 4.14 [1.97-8.68]) and role ambiguity (OR = 9.71 [4.08-23.14]) were associated with higher depressive scores in vice-principals. CONCLUSIONS: Clarifying job roles for principals and vice-principals, reducing quantitative workload for principals and increasing supervisory support for vice-principals may be important for mitigating depression for school principals and vice-principals in Japan.


Assuntos
Pessoal Administrativo/psicologia , Depressão/epidemiologia , Estresse Ocupacional/epidemiologia , Instituições Acadêmicas , Estudos Transversais , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Apoio Social , Inquéritos e Questionários , Carga de Trabalho/estatística & dados numéricos
5.
Occup Med (Lond) ; 68(3): 171-176, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29506081

RESUMO

Background: Work-related stressors are associated with low sleep quality. However, few studies have reported an association between role stressors and sleep quality. Aims: To elucidate the association between role stressors (including role conflict and ambiguity) and sleep quality. Methods: Cross-sectional study of daytime workers whose sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Work-related stressors, including role stressors, were assessed using the Generic Job Stress Questionnaire (GJSQ). The association between sleep quality and work-related stressors was investigated by logistic regression analysis. Results: A total of 243 participants completed questionnaires were received (response rate 71%); 86 participants reported poor sleep quality, based on a global PSQI score ≥6. Multivariable logistic regression analysis revealed that higher role ambiguity was associated with global PSQI scores ≥6, and that role conflict was significantly associated with sleep problems, including sleep disturbance and daytime dysfunction. Conclusions: These results suggest that high role stress is associated with low sleep quality, and that this association should be considered an important determinant of the health of workers.


Assuntos
Estresse Ocupacional/complicações , Papel Profissional/psicologia , Jornada de Trabalho em Turnos/efeitos adversos , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Ocupacional/psicologia , Psicometria/instrumentação , Psicometria/métodos , Jornada de Trabalho em Turnos/psicologia , Transtornos do Sono-Vigília/complicações , Inquéritos e Questionários
6.
J Hosp Infect ; 94(2): 150-3, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27346624

RESUMO

Inpatients who had been in close contact with patients with influenza were given oseltamivir [75mg capsules once daily for adults or 2mg/kg (maximum of 75mg) once daily for children] for three days as postexposure prophylaxis (PEP). The index patients with influenza were prescribed a neuraminidase inhibitor and were discharged immediately or transferred to isolation rooms. The protective efficacy of oseltamivir for three days was 93% overall [95% confidence interval (CI) 53-99%; P=0.023] and 94% for influenza A (95% CI 61-99%; P=0.017), which is comparable to that of seven- to 10-day regimens of oseltamivir as PEP.


Assuntos
Antivirais/administração & dosagem , Quimioprevenção/métodos , Influenza Humana/prevenção & controle , Oseltamivir/administração & dosagem , Profilaxia Pós-Exposição/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
7.
Neuroscience ; 284: 632-642, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25450961

RESUMO

The primary vestibular neurons convey afferent information from hair cells in the inner ear to the vestibular nuclei and the cerebellum. The intrinsic firing properties of vestibular ganglion cells (VGCs) are heterogeneous to sustained membrane depolarization, and undergo marked developmental changes from phasic to tonic types during the early postnatal period. Previous studies have shown that low-voltage-activated potassium channels, Kv1 and Kv7, play a critical role in determining the firing pattern of VGCs. In the present study, we explored the developmental changes in the properties of hyperpolarization-activated current (Ih) in rat VGCs and the role played by Ih in determining the firing properties of VGCs. Tonic firing VGCs showed a larger current density of Ih as compared to phasic firing VGCs, and tonic firing VGCs became phasic firing in the presence of ZD7288, an Ih channel blocker, indicating that Ih contributes to control the firing pattern of VGCs. The amplitude of Ih increased and the activation kinetics of Ih became faster during the developmental period. Analysis of developmental changes in the expression of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels revealed that expression of HCN1 protein and its mRNA increased during the developmental period, whereas expression of HCN2-4 protein and its mRNA did not change. Our results suggest that HCN1 channels as well as Kv1 channels are critical in determining the firing pattern of rat VGCs and that developmental up-regulation of HCN1 transforms VGCs from phasic to tonic firing phenotypes.


Assuntos
Potenciais de Ação/fisiologia , Gânglios Sensitivos/crescimento & desenvolvimento , Neurônios/fisiologia , Nervo Vestibular/crescimento & desenvolvimento , Potenciais de Ação/efeitos dos fármacos , Animais , Western Blotting , Células Cultivadas , Gânglios Sensitivos/efeitos dos fármacos , Gânglios Sensitivos/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Neurônios/efeitos dos fármacos , Neurotransmissores/farmacologia , Técnicas de Patch-Clamp , Canais de Potássio/metabolismo , Pirimidinas/farmacologia , RNA Mensageiro/metabolismo , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Nervo Vestibular/efeitos dos fármacos , Nervo Vestibular/fisiologia
9.
AJNR Am J Neuroradiol ; 33(11): 2167-70, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22595898

RESUMO

BACKGROUND AND PURPOSE: Restenosis after CAS is a postoperative problem, with a reported frequency of approximately 2%-8%. However differences in stent design, procedure, and the antiplatelet agent appear to affect the incidence of restenosis. We assessed the frequency of restenosis and the effect of the antiplatelet agent CLZ in preventing restenosis after CAS by the standard procedure using the CWS. MATERIALS AND METHODS: Between May 2010 and October 2011, 62 lesions in 60 consecutive patients underwent CAS using the CWS at 4 medical institutions, and all patients were followed clinically and assessed by sonography, 3D-CTA, or angiography at 3 and 6 months postoperatively. Restenosis was defined as ≥50% stenosis. The incidence of restenosis and the variation in the incidence of restenosis by the difference in type of antiplatelet agent between the CLZ group (n = 30; aspirin, 100 mg, and CLZ, 200 mg) and the non-CLZ group (n = 32; aspirin, 100 mg, and clopidogrel, 75 mg [n = 29]; or ticlopidine, 100 mg [n = 2] or 200 mg [n = 1]) were retrospectively investigated. Two antiplatelet agents were given starting 1 week preoperatively until at least 3 months postoperatively. RESULTS: Restenosis occurred in 5 patients (8.3%), but all were cases of asymptomatic lesions in the follow-up period. All 5 patients with restenosis were in the non-CLZ group, with no cases of restenosis in the CLZ group; the difference was significant (P = .0239). CONCLUSIONS: The restenosis rate after CAS by using the CWS was 8.3%. CLZ was associated with significant inhibition of restenosis.


Assuntos
Doenças das Artérias Carótidas/cirurgia , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/prevenção & controle , Pré-Medicação/métodos , Stents/efeitos adversos , Tetrazóis/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Doenças das Artérias Carótidas/complicações , Cilostazol , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Estudos Retrospectivos , Resultado do Tratamento , Vasodilatadores/administração & dosagem
10.
Bone Marrow Transplant ; 45(5): 912-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19802024

RESUMO

Chronic GVHD (cGVHD) of the liver is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-SCT). It is characterized by the destruction of bile duct epithelium followed by progressive cholestasis, which resembles primary biliary cirrhosis (PBC) clinically and histologically. Bezafibrate (BF) is a widely used agent for hyperlipidemia that is also effective in ursodeoxycholic acid (UDCA)-resistant PBC patients. The putative mechanism in cholestasis is that BF upregulates the expression of phosphatidylcholine flippase on bile canaliculi, facilitates phospholipid output into bile and relieves bile duct damage caused by hydrophobic bile salts. Therefore, the effects of BF in patients with cGVHD of the liver were investigated. Of 87 patients with cGVHD who survived more than 100 days after SCT, 8 were given BF to treat liver cGVHD because of a poor therapeutic response to UDCA and immunosuppressants. The serum alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (gamma-GTP) levels decreased significantly within 1 month after initiation of BF therapy compared with those before BF therapy in all patients (ALP, 964.9.0+/-306.9 to 597.8+/-102.5 IU/l, P=0.012; gamma-GTP, 528.8+/-299.0 to 269.0+/-119.9 IU/l, P=0.012). BF was effective in patients with liver cGVHD, including UDCA-resistant patients. BF could be a novel therapeutic option for liver cGVHD that helps to preserve normal immunity with the antileukemic effect of cGVHD.


Assuntos
Bezafibrato/uso terapêutico , Doença Enxerto-Hospedeiro/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hepatopatias/terapia , Adulto , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/complicações , Doença Enxerto-Hospedeiro/diagnóstico , Humanos , Hepatopatias/complicações , Hepatopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Homólogo
11.
Clin Genet ; 76(4): 383-91, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19737284

RESUMO

Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A, which accounts for 74-90% of USH2 cases. This is the first study reporting the results of scanning for USH2A mutations in Japanese patients with USH2. In 8 of 10 unrelated patients, we identified 14 different mutations. Of these mutations, 11 were novel. Although the mutation spectrum that we identified differed from that for Caucasians, the incidence of mutations in USH2A was 80% for all patients tested, which is consistent with previous findings. Further, c.8559-2A>G was identified in four patients and accounted for 26.7% of mutated alleles; it is thus a frequent mutation in Japanese patients. Hence, mutation screening for c.8559-2A>G in USH2A may prove very effective for the early diagnosis of USH2.


Assuntos
Proteínas da Matriz Extracelular/genética , Predisposição Genética para Doença/genética , Mutação/genética , Síndromes de Usher/genética , Adulto , Povo Asiático , Análise Mutacional de DNA , Primers do DNA/genética , Feminino , Testes Genéticos , Humanos , Japão , Masculino , Pessoa de Meia-Idade
12.
Ann N Y Acad Sci ; 1164: 344-6, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19645924

RESUMO

Bone-conducted vibration of the forehead, in the midline at the hairline (Fz) causes linear acceleration stimulation of both mastoids and results in an ocular vestibular-evoked myogenic potential (oVEMP), recorded by surface electromyogram (EMG) electrodes just beneath the eyes. The early n10 component of the oVEMP is symmetrical in healthy subjects, absent in patients with bilateral vestibular loss, and in patients after unilateral vestibular loss (uVL) n10 is small or absent on the side contralateral to the uVL, but of normal amplitude on the side contralateral to the healthy ear. The n10 component probably reflects mainly otolithic function, since in the guinea pig, primary otolith irregular neurons are selectively activated by bone-conducted vibration (BCV) at low intensities (0.1 g), whereas semicircular canal primary afferents are not activated even at high intensities (10 g).


Assuntos
Osso e Ossos/fisiologia , Membrana dos Otólitos/fisiologia , Humanos , Vibração
13.
Clin Neurophysiol ; 120(3): 588-93, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19211301

RESUMO

OBJECTIVE: The n10 component (n10) of the ocular vestibular evoked myogenic potential (oVEMP) to brief bone conducted vibration (BCV) of the forehead at Fz is probably caused by the vibration selectively activating vestibular otolithic receptors. If the n10 is due primarily to utricular activation then diseases which affect only the superior division of the vestibular nerve (SVN) should reduce or eliminate n10. METHODS: The n10 component of the oVEMP was measured in 13 patients with unilateral SVN but with inferior vestibular nerve function preserved. RESULTS: We compared the n10 to BCV of these 13 SVN patients to previously published data for healthy subjects and patients after complete unilateral vestibular loss. We found that in 12 out of the 13 patients with SVN, n10 was markedly reduced or absent under the contralesional eye. CONCLUSION: Since all utricular afferents course in the superior vestibular nerve and in 12/13 of these patients the n10 was reduced we conclude that the n10 component of the oVEMP to BCV is probably mediated by the superior vestibular nerve and probably due to activation of mainly utricular receptors. SIGNIFICANCE: The n10 appears to be a simple new test of superior vestibular nerve and probably mainly utricular function.


Assuntos
Condução Óssea/fisiologia , Potenciais Evocados/fisiologia , Músculos do Pescoço/fisiologia , Músculos Oculomotores/fisiologia , Reflexo Vestíbulo-Ocular/fisiologia , Nervo Vestibular/fisiologia , Adulto , Idoso , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Oculomotores/inervação , Membrana dos Otólitos/fisiologia , Estimulação Física , Sáculo e Utrículo/fisiologia , Vestíbulo do Labirinto/fisiologia , Vibração
15.
Audiol Neurootol ; 13(6): 396-404, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18663292

RESUMO

If a patient, who is lying supine and looking upward, is given bone-conducted vibration (BCV) of the forehead at the hairline in the midline (Fz) with a clinical reflex hammer or a powerful bone conduction vibrator, short-latency surface potentials called ocular vestibular evoked myogenic potentials (oVEMP) can be recorded from just beneath the eyes. The early negative (excitatory) component (n10) is approximately equal in amplitude for both eyes in healthy subjects, but in patients with unilateral vestibular loss, the n10 component is significantly asymmetrical under the 2 eyes - the n10 component is small or absent under the eye on the side contralateral to the prior unilateral vestibular nerve removal, but of normal amplitude under the eye on the side contralateral to the healthy ear. The n10 component of the oVEMP response to BCV at Fz stimuli reflects vestibular and probably mainly otolithic function via crossed otolithic-ocular pathways, and so n10 asymmetry is a new way of identifying the affected side in patients with unilateral otolithic loss.


Assuntos
Eletromiografia/métodos , Testa/fisiologia , Membrana dos Otólitos/fisiopatologia , Doenças Vestibulares/diagnóstico , Doenças Vestibulares/fisiopatologia , Adulto , Condução Óssea , Potenciais Evocados , Feminino , Testa/inervação , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Neuroma Acústico/fisiopatologia , Neuroma Acústico/cirurgia , Tempo de Reação , Nervo Vestibular/fisiologia , Nervo Vestibular/cirurgia , Vibração
16.
Clin Neurophysiol ; 119(9): 2135-47, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18639490

RESUMO

OBJECTIVE: To provide the empirical basis for using ocular vestibular evoked myogenic potentials (oVEMPS) in response to Fz bone conducted vibration (BCV) stimulation to indicate vestibular function in human subjects. To show the generality of the response by testing a large number of unselected healthy subjects across a wide age range and the repeatability of the response within subjects. To provide evidence that the response depends on otolithic function. METHODS: The early negative component (n10) of the oVEMP to brief BCV of the forehead, in the midline at the hairline (Fz) is recorded by surface EMG electrodes just beneath the eyes. We used a Bruel and Kjaer 4810 Mini-Shaker or a light tap with a tendon hammer to provide adequate BCV stimuli to test a large number (67) of unselected healthy people to quantify the individual differences in n10 magnitude, latency and symmetry to Fz BCV. A Radioear B-71 bone oscillator at Fz is not adequate to elicit a reliable n10 response. RESULTS: The n10 oVEMP response showed substantial differences in amplitude between subjects, but is repeatable within subjects. n10 is of equal magnitude in both eyes with an average asymmetry around 11%. The average n10 amplitude for Mini Tone Burst BCV is 8.47microV+/-4.02 (sd), the average latency is 10.35ms+/-0.63 (sd). The amplitude of n10 decreases and its latency increases with age. CONCLUSIONS: oVEMPs are a new reliable, repeatable test to indicate vestibular and probably otolithic function. SIGNIFICANCE: This study shows the optimum conditions for recording oVEMPs and provides baseline values for individual differences and asymmetry. oVEMPs can be measured in senior subjects without difficulty.


Assuntos
Condução Óssea/fisiologia , Potenciais Evocados Auditivos/fisiologia , Músculos Oculomotores/fisiologia , Prosencéfalo/fisiologia , Vibração , Estimulação Acústica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletromiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Oculomotores/inervação , Tempo de Reação/fisiologia , Som , Doenças Vestibulares/fisiopatologia
17.
Radiat Environ Biophys ; 47(3): 343-8, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18496703

RESUMO

The upper and lower limits of the excitation function of the (63)Cu(n,p)(63)Ni reaction were experimentally determined, and the number of (63)Ni nuclei produced in copper samples exposed to atomic bomb neutrons in Hiroshima was estimated by using the experimental excitation functions and the neutron fluences given in the DS02 dosimetry system. The estimated number of (63)Ni nuclei was compared with that measured and with that calculated using the DS02 dosimetry system and the corresponding ENDF/B-VI cross section. In comparison with DS02, there is about a 60% maximum difference in (63)Ni production at the hypocenter when the experimental upper cross section values are used. The difference becomes smaller at greater distances from the hypocenter and decreases, for example, to less than 30 and 5% when using the upper and lower experimental cross sections at 1,000 m, respectively.


Assuntos
Cobre/análise , Nêutrons , Níquel/análise , Guerra Nuclear , Radioisótopos/análise , Japão
18.
AJNR Am J Neuroradiol ; 29(7): 1329-34, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18451088

RESUMO

BACKGROUND AND PURPOSE: Visual field defects sometimes occur after temporal resection surgery. Our purpose was to evaluate the correlation between visual field defects caused by temporal lobe resection and the degree of resection of the Meyer loop, as assessed by diffusion tensor tractography. MATERIALS AND METHODS: We examined 14 patients who underwent temporal resection for temporal lobe epilepsy. We obtained presurgical tractographies and then measured the distance between the temporal tip and the anterior limit of the Meyer loop (T-M distance). The degree of resection of the Meyer loop was defined as the distance from the anterior limit of the Meyer loop to the posterior limit of the temporal lobe resection (M-R distance). This was calculated by subtracting the T-M distance from the measured distance between the temporal tip and the posterior limit of the resection (T-R distance). RESULTS: The mean T-M distance was 36.6 mm. The interindividual variation of the distance ranged from 30.0 to 43.2 mm. Although there was no statistically significant correlation between the extent of the visual field defect and the T-R distance, there was a statistically significant correlation between the degree of the visual field defect and the M-R distance. CONCLUSION: The range of interindividual variation for the position of the Meyer loop was rather large, indicating that this variation is the key factor in visual field defects after temporal lobectomy, and the visual field defect appears to be predicted by presurgical tractography. Evaluation of the Meyer loop through the use of tractography seems to be a feasible method, which can be used to predict the visual field defect after temporal lobe resection.


Assuntos
Lobectomia Temporal Anterior/métodos , Imagem de Difusão por Ressonância Magnética , Epilepsia do Lobo Temporal/cirurgia , Aumento da Imagem , Processamento de Imagem Assistida por Computador , Complicações Pós-Operatórias/diagnóstico , Campos Visuais/fisiologia , Vias Visuais/lesões , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Esclerose/patologia , Esclerose/cirurgia , Lobo Temporal/patologia , Vias Visuais/patologia
19.
Appl Radiat Isot ; 66(10): 1321-4, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18467114

RESUMO

The excitation function for the (63)Cu(n,p)(63)Ni reaction has been measured by activation method using the 4.5 MV Dynamitron accelerator of the Fast Neutron Laboratory of Tohoku University. Copper plates and hollow spherical copper shells were irradiated by neutrons of various energy up to 14.9 MeV produced by the T(p,n), D(d,n), and T(d,n) reactions. The (63)Ni produced in the irradiated copper target was chemically separated. The beta-rays emitted from the extracted (63)Ni were measured by a liquid scintillation method. The cross sections obtained were compared with the evaluated data files of JENDL-3.3, ENDF/B-VI and FENDL/A-2.0. Consequently, it is found that FENDL/A-2.0 is consistent with our experimental data in the energy range studied in this work. The effect of proton shell appeared in the excitation function obtained is also discussed.


Assuntos
Cobre/química , Cobre/efeitos da radiação , Transferência Linear de Energia , Nêutrons , Níquel/química , Níquel/efeitos da radiação , Radioisótopos/química , Radioisótopos/efeitos da radiação , Relação Dose-Resposta à Radiação , Doses de Radiação
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