1,288 research outputs found

    Evaluation or perfusion and thermal parameters of skiin tissue using cold provocation and thermographic measurements

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    Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed

    Surface imaging of metallic material fractures using optical coherence tomography

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    We demonstrate the capability of optical coherence tomography (OCT) to perform topography of metallic surfaces after being subjected to ductile or brittle fracturing. Two steel samples, OL 37 and OL 52, and an antifriction Sn-Sb-Cu alloy were analyzed. Using an in-house-built swept source OCT system, height profiles were generated for the surfaces of the two samples. Based on such profiles, it can be concluded that the first two samples were subjected to ductile fracture, while the third one was subjected to brittle fracture. The OCT potential for assessing the surface state of materials after fracture was evaluated by comparing OCT images with images generated using an established method for such investigations, scanning electron microscopy (SEM). Analysis of cause of fracture is essential in response to damage of machinery parts during various accidents. Currently the analysis is performed using SEM, on samples removed from the metallic parts, while OCT would allow in situ imaging using mobile units. To the best of our knowledge, this is the first time that the OCT capability to replace SEM has been demonstrated. SEM is a more costly and time-consuming method to use in the investigation of surfaces of microstructures of metallic materials. © 2014 Optical Society of America

    The functional neuroanatomy of bipolar disorder:a consensus model

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    OBJECTIVES: Functional neuroimaging methods have proliferated in recent years, such that functional magnetic resonance imaging, in particular, is now widely used to study bipolar disorder. However, discrepant findings are common. A workgroup was organized by the Department of Psychiatry, University of Cincinnati (Cincinnati, OH, USA) to develop a consensus functional neuroanatomic model of bipolar I disorder based upon the participants' work as well as that of others. METHODS: Representatives from several leading bipolar disorder neuroimaging groups were organized to present an overview of their areas of expertise as well as focused reviews of existing data. The workgroup then developed a consensus model of the functional neuroanatomy of bipolar disorder based upon these data. RESULTS: Among the participants, a general consensus emerged that bipolar I disorder arises from abnormalities in the structure and function of key emotional control networks in the human brain. Namely, disruption in early development (e.g., white matter connectivity and prefrontal pruning) within brain networks that modulate emotional behavior leads to decreased connectivity among ventral prefrontal networks and limbic brain regions, especially the amygdala. This developmental failure to establish healthy ventral prefrontal-limbic modulation underlies the onset of mania and ultimately, with progressive changes throughout these networks over time and with affective episodes, a bipolar course of illness. CONCLUSIONS: This model provides a potential substrate to guide future investigations and areas needing additional focus are identified

    Evidence of cerebellar involvement in the onset of a manic state

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    We described the cerebello-cerebral functional connectivity in a subject who developed a manic state after a cerebellar lesion. Whole brain investigation, performed by means of an advanced MRI examination, evidenced an isolated lesion involving the left lobules VI, VIIa (crus I), and IX and the posterior area of the vermis. The cerebello-cerebral functional connectivity analysis detected a pattern of altered connectivity in specific areas of the prefrontal-striatal-thalamic circuits that are typically altered in bipolar subjects during the manic state. Specifically, a pattern of hypo-connectivity was found between the cerebellum and cerebral regions known to be implicated in emotion modulation and social interaction. Conversely, a pattern of hyper-connectivity was found between the cerebellum and posterior cerebral cortical regions that are involved in sensorimotor functions. The present study represents the first evidence that dysregulation of cerebral networks consequent to a cerebellar lesion is at the root of bipolar disorder, at least the manic state, and provides a new framework for interpreting cerebellar modulation in the regulation of mood in specific psychiatric conditions

    Cross-correlation based movement correction method for biomedical dynamic infrared imaging

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    Abstract During dynamic infrared imaging there is a need of temperature measurement along time at a point or area. The paper shows the recent studies using dynamic infrared imaging in medicine and problems of proper data extraction which is the result of an object movement. The method of movement correction based on cross correlation calculated for dynamic thermal imaging is presented. The influence of movement correction on extracted data and point tracking precision is shown. The proposed method has been successfully applied for cold stress diagnosis during breast cancer screening

    Effects of age and leg length upon central loop of the Gastrocnemius-soleus H-reflex latency

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    BACKGROUND: central loop of the gastrocnemius-soleus H-reflex latency (T(c)) that looks promising in the diagnosis of S1 radiculopathy; has been investigated in a few studies and only two of them have focused on the constitutional factors affecting it. Although leg length has been shown to contribute to the T(c), the role of age is controversial. More confusing, none of the previously performed studies have used strict criteria to rule out subclinical neuropathy, so the results could be misleading. This study has been performed to determine the influence of leg length and age on T(c )among a carefully selected group of healthy volunteers. METHODS: after screening forty six volunteers by taking history, physical examination and a brief electrophysiologic study; forty of them were selected to enroll into the study. T(c )was obtained in all the study subjects and leg length and age were recorded for correlational analyses. RESULTS: this group was consisted of 26 males (65%) and 14 females (35%) with the age range of 19–65 years (Mean ± SD: 37 ± 10.7) and leg length range of 29.5–43 centimeters (36.4 ± 3.4). Mean ± SD for T(c )was 6.78 ± 0.3. We found a significant correlation between T(c )and leg length (p value= 0.003, r = 0.49 and confidence interval 95% = 0.59–0.88), no significant correlation was found between age and T(c )(p value= 0.48, r = 0.11), also we obtained the regression equation as: T(c )= 0.04L + 5.28 CONCLUSIONS: in contrast to leg length, age was not correlated with T(c). Future studies are required to delineate other contributing factors to T(c)

    Amphetamine, but not methylphenidate, increases ethanol intake in adolescent male, but not in female, rats

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    Introduction: There has been an increasing interest in analyzing the interactions between stimulants and ethanol during childhood and adolescence. Stimulants are used to treat attention-deficit hyperactivity disorder (ADHD) in these developmental stages, during which ethanol initiation and escalation often occur. Methods: This study assessed the effects of repeated d-amphetamine (AMPH) or methylphenidate (MPH) treatment during adolescence [male and female Wistar rats, between postnatal day (PD) 28 to PD34, approximately] on the initiation of ethanol intake during a later section of adolescence (PD35 to PD40). Results: Amphetamine and MPH exerted reliable acute motor stimulant effects, but there was no indication of sensitized motor or anxiety responses. MPH did not affect dopamine (DA) levels, whereas AMPH significantly reduced insular levels of DA in both sexes and norepinephrine levels in females only. Repeated treatment with AMPH, but not with MPH, enhanced ethanol intake during late adolescence in male, but not in female, rats. Conclusion: A short treatment with AMPH during adolescence significantly altered DA levels in the insula, both in male and females, and significantly enhanced ethanol intake in males. The present results suggest that, in adolescent males, a very brief history of AMPH exposure can facilitate the initiation of ethanol intake.Fil: Ruiz, Paul. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂ­n Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂ­n Ferreyra; Argentina. Universidad de la RepĂșblica; UruguayFil: Calliari, Aldo. Universidad de la RepĂșblica; UruguayFil: Genovese, Patricia. Universidad de la RepĂșblica; UruguayFil: Scorza, Cecilia. Instituto de Investigaciones BiolĂłgicas "Clemente Estable"; UruguayFil: Pautassi, Ricardo Marcos. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂ­n Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂ­n Ferreyra; Argentina. Universidad Nacional de CĂłrdoba. Facultad de PsicologĂ­a; Argentin

    Manic Episode Associated with Mega Cisterna Magna

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    Mega cisterna magna is a part of "Dandy-Walker Complex" and it is characterized by the enlargement of the cisterna magna, morphologically intact vermis and cerebellar hemispheres. We report a case of manic attack in a 23-year-old man with mega cisterna magna. The patient was treated with quetiapine 1,000 mg/day and sodium valproate 1,500 mg/day and the symptoms were ameliorated within 2.5 months. In this case, mega cisterna magna and manic symptoms may be found together coincidentally or any cerebellar dysfunction due to mega cisterna magna may cause or contribute to the appearance of affective symptoms. To our knowledge, this is the first case reporting manic attack with psychotic symptoms associated with mega cisterna magna. This report suggests that any lesion in the cerebellum might contribute to the occurrences of some affective and psychotic symptoms seen in bipolar disorder

    The association of genetic variation in CACNA1C with structure and function of a frontotemporal system

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    OBJECTIVES: A single nucleotide polymorphism at the CACNA1C gene (rs1006737) has been reported in genome-wide association studies to be associated with bipolar disorder (BD) with genome-wide significance. However, the neural system effects of CACNA1C that mediate the association are not known. In this study, we assessed associations between rs1006737 variation and both morphology and functional connectivity within a corticolimbic frontotemporal neural system implicated in BD. METHODS: A total of 55 European Americans were divided into two groups: a GG group homozygous for the 'G' allele (n = 30) and carriers of the high risk A allele ('A-carrier' group, AA/AG genotypes; n = 25). The subjects participated in both high-resolution structural magnetic resonance imaging (MRI) scans and functional MRI scans during emotional face-processing. Voxel-based morphometry and functional connectivity analyses were performed. RESULTS: Compared to the GG group, the A-carrier group showed significantly increased gray matter volume and reduced functional connectivity within a corticolimbic frontotemporal neural system (p < 0.05, corrected). CONCLUSION: The findings support effects of the rs1006737 variation on the frontotemporal neural system implicated in BD, both in gray matter morphology and functional connectivity. This suggests that influence of CACNA1C variation on corticolimbic structure and function may be a mechanism contributing to the neural circuitry of BD
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