443 research outputs found
Improvements of single sheet testers for measurement of 2-D magnetic properties up to high flux density
Due to structural limitation, the currently proposed apparatus based on a single sheet tester (SST) cannot measure magnetic properties along arbitrary directions (so-called 2-D magnetic properties) of silicon steel at high flux densities. In this paper, significant improvements are carried out on magnetizing windings and auxiliary yokes of a double excitation type of SST. Furthermore, crosswise overlapped H-coils are introduced so that even an ordinary single-excitation type of SST can be applicable to the measurements of 2-D properties. It is demonstrated that 2-D magnetization property up to 1.9 T can be measured by using the newly developed SST's</p
Functional significance of central D1 receptors in cognition: beyond working memory
The role of dopamine D1 receptors in prefrontal cortex function, including working memory, is well acknowledged. However, relatively little is known about their role in other cognitive or emotional functions. We measured both D1 and D2 receptors in the brain using positron emission tomography in healthy subjects, with the aim of elucidating how regional D1 and D2 receptors are differentially involved in cognitive and emotional functions beyond working memory. We found an inverted U-shaped relation between prefrontal D1 receptor availability and Wisconsin Card Sorting Test performance, indicating that too little or too much D1 receptor stimulation impairs working memory or set shifting. In addition, variability of D1 receptor availability in the amygdala and striatum was related to individual differences in emotional responses and decision-making processes, respectively. These observations suggest that the variability of available D1 receptors might be associated with individual differences in brain functions that require phasic dopamine release. An interdisciplinary approach combining molecular imaging of dopamine neurotransmission with cognitive neuroscience and clinical psychiatry will provide new perspectives for understanding the neurobiology of neuropsychiatric disorders such as schizophrenia, addiction and Parkinson's disease, as well as novel therapeutics for cognitive impairments observed in them
コウクウガン ケイブ テンイ リンパセツ ノ ケンシュツ ニ タイスル チョウオウパ サンジゲン イメージング ノ ユウヨウセイ
Three dimensional ultrasonographic imaging was performed for the cervical lymphadenopathy. Forty lymph nodes with suspicion of metastatic lymphadenopathy out of 20 patients with oral cancers were served for the present study. We could not judge the presence/absence of the metastasis by routine B mode or power Doppler imaging alone. Out of the 40 lymph nodes, 18 metastatic lymphadenopathies were proved histopathologically. Additionally, 11 lymph nodes out of 8 patients with nonspecific reactive lymphadenopathies were included as the control. The pattern of the circumferential blood flow of the lymph nodes was reviewed by the three-dimensional maximum intensity projection (3D MIP) view that was obtained from 3D power Doppler imaging. They were divided into 4 categories ; linear blood flow, mesh like blood flow, spotty blood flow and no circumferential flow. The spotty flow was almost exclusively found in the metastatic lymph nodes. Its accuracy, sensitivity and specificity, positive predictive value and negative predictive value for detecting metastatic lymphadenopathy were 0.73, 0.44, 0.95, 0.89, and 0.68, respectively. This spotty flow was situated at the marginal portion and/or around the lymph nodes by the analysis of the two-dimensional display. We could not differentiate whether it was arterial or venous flow. As the three dimensional sonographic imaging is the time-consuming technique compared to the routine B mode or power Doppler imaging, we cannot routinely perform it. However, it would play a supplementary role for detecting lymph node metastasis, especially if we cannot judge them by the two dimensional imaging alone
Reflected glory and failure: the role of the medial prefrontal cortex and ventral striatum in self vs other relevance during advice-giving outcomes
Despite the risks, people enjoy giving advice. One explanation is that giving beneficial advice can result in reflected glory, ego boosts or reputation enhancement. However, giving poor advice can be socially harmful (being perceived as incompetent or untrustworthy). In both circumstances, we have a vested interest in the advice follower's success or failure, especially when it reflects specifically on us compared with when it is diffused between multiple advisors. We examined these dynamics using an Advisor-Advisee Game, where subjects acted as an Advisor to a confederate Advisee who selected one of the three options when trying to win money: accept the subject's advice, accept the advice of a second confederate Advisor or accept both Advisors' advice. Results showed that having one's advice accepted, compared with being rejected, resulted in activity in the ventral striatum--a core reward area. Furthermore, the ventral striatum was only active when the subject's advice led to the advisee winning, and not when the advisee won based on the confederate's advice. Finally, the medial prefrontal cortex (MPFC) was more active when the Advisee won or lost money based solely on the subject's advice compared with when the second Advisor's advice was accepted. One explanation for these findings is that the MPFC monitors self-relevant social information, while the ventral striatum is active when others accept advice and when their success leads to reflected glory
Functional relevance of the precuneus in verbal politeness.
Non-competitive and non-threatening aspects of social hierarchy, such as politeness, are universal among human cultures, and might have evolved from ritualized submission in primates; however, these behaviors have rarely been studied. Honorific language is a type of polite linguistic communication that plays an important role in human social interactions ranging from everyday conversation to international diplomacy. Here, functional magnetic resonance imaging (fMRI) revealed selective precuneus activation during a verbal politeness judgment task, but not other linguistic-judgment or social-status recognition tasks. The magnitude of the activation was correlated with the task performance. Functional suppression of the activation using cathodal transcranial direct-current stimulation reduced performance in the politeness task. These results suggest that the precuneus is an essential hub of the verbal politeness judgment
Resting-state functional connectivity-based biomarkers and functional MRI-based neurofeedback for psychiatric disorders: a challenge for developing theranostic biomarkers
Psychiatric research has been hampered by an explanatory gap between
psychiatric symptoms and their neural underpinnings, which has resulted in poor
treatment outcomes. This situation has prompted us to shift from symptom-based
diagnosis to data-driven diagnosis, aiming to redefine psychiatric disorders as
disorders of neural circuitry. Promising candidates for data-driven diagnosis
include resting-state functional connectivity MRI (rs-fcMRI)-based biomarkers.
Although biomarkers have been developed with the aim of diagnosing patients and
predicting the efficacy of therapy, the focus has shifted to the identification
of biomarkers that represent therapeutic targets, which would allow for more
personalized treatment approaches. This type of biomarker (i.e., theranostic
biomarker) is expected to elucidate the disease mechanism of psychiatric
conditions and to offer an individualized neural circuit-based therapeutic
target based on the neural cause of a condition. To this end, researchers have
developed rs-fcMRI-based biomarkers and investigated a causal relationship
between potential biomarkers and disease-specific behavior using functional MRI
(fMRI)-based neurofeedback on functional connectivity. In this review, we
introduce recent approach for creating a theranostic biomarker, which consists
mainly of two parts: (i) developing an rs-fcMRI-based biomarker that can
predict diagnosis and/or symptoms with high accuracy, and (ii) the introduction
of a proof-of-concept study investigating the relationship between normalizing
the biomarker and symptom changes using fMRI-based neurofeedback. In parallel
with the introduction of recent studies, we review rs-fcMRI-based biomarker and
fMRI-based neurofeedback, focusing on the technological improvements and
limitations associated with clinical use.Comment: 46 pages, 5 figure
コウクウ ガク ガンメン アクセイ シュヨウ ノ エンカク テンイ ヒョウカ ニオケル クカンブ CT ケンサ ノ イチズケ
Abdominal CT examinations for the scouting of distant metastasis (DM) of orofacial malignant tumors were retrospectively evaluated, for the purpose of establishing the standard way of examination. Out of 159 patients with oral malignancies, 247 abdominal CT examinations were performed for the purpose of scouting DM. During the examination, intravenous contrast enhancement (CE) was performed in 166 examinations. DM were detected in 13 patients (8.2%). DM were found in 6 at administration, and 8 were late DM. Nine DM were detected out of 166 (5.4%) examinations with CE, and 5 were detected out of 81 (6.2%) examinations without CE. In detecting the DM, no improvement was found by CE. DM attacked lungs in 13, mediastinum in 3, liver in 2, paraaortic lymph nodes in 1, chest wall in 1, and vertebra in 1. Only 2 patients with DM were free from cervical metastasis, and the remainder was combined with cervical metastasis, regardless the status of the primary sites. Conclusions: Abdominal CT was useful for detecting DM. Intravenous CE was not necessary for scouting the DM. Patients with cervical metastasis had a high potential for developing DM
Altered awareness of action in Parkinson’s disease: evaluations by explicit and implicit measures
Deficits in the integration of motor prediction and its feedback have been reported in Parkinson's disease. Conscious awareness of action is proposed to emerge under the integration of motor prediction and its feedback. Thus, it may lead to changes in the awareness of the authorship of action (in other words, the sense of agency) in Parkinson's disease. We have employed both explicit and implicit measures to assess the awareness of action in Parkinson's disease and matched controls. As an explicit measure, an action recognition task requiring explicit judgments was used. Patients showed less attribution of their movements to non-biased and angular-biased visual feedbacks. As an implicit measure, the temporal attraction between the perceived time of actions and their effects, which is known as intentional binding task, was used. While action-effect association was observed in the control group, actions were not experienced as having shifted towards their subsequent effects in the patient group. These tendencies were consistent regardless of the side of the asymmetrical motor symptoms. These results may reflect an underlying abnormality in the awareness of voluntary action in Parkinson's disease
Explicit and implicit effects of gaming content on social media on the behavior of young adults
Excessive gameplay can have negative effects on both mental and physical health, especially among young people. Nowadays, social media platforms are bombarding users with gaming-related content daily. Understanding the effect of this content on people’s behavior is essential to gain insight into problematic gaming habits. However, this issue is yet to be studied extensively. In this study, we examined how gaming-related content on social media affects young adults explicitly and implicitly. We studied 25 healthy young adults (average age 21.5 ± 2.2) who played online games casually and asked them to report their gaming desire. We also conducted an implicit association test (IAT) to measure their implicit attitudes toward gaming-related content. We also investigated the relationship between these measures and various psychological factors, such as personality traits, self-efficacy, impulsiveness, and cognitive flexibility. The results revealed that participants had a higher explicit gaming desire when exposed to gaming-related cues on social media than neutral cues. They also had a robust positive implicit attitude toward gaming-related content on social media. Explicit gaming desire was positively correlated with neuroticism levels. Furthermore, the IAT effect was negatively correlated with self-efficacy and cognitive flexibility levels. However, there were no significant correlations between explicit gaming desire/IAT effect and impulsiveness levels. These findings suggest that gaming-related content on social media can affect young adults’ behavior both explicitly and implicitly, highlighting the need for further research to prevent gaming addiction in vulnerable individuals
- …