643 research outputs found

    Frequency limits of sequential readout for sensing AC magnetic fields using nitrogen-vacancy centers in diamond

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    The nitrogen-vacancy (NV) centers in diamond have ability to sense alternating-current (AC) magnetic fields with high spatial resolution. However, the frequency range of AC sensing protocols based on dynamical decoupling (DD) sequences has not been thoroughly explored experimentally. In this work, we aimed to determine the sensitivity of ac magnetic field as a function of frequency using sequential readout method. The upper limit at high frequency is clearly determined by Rabi frequency, in line with the expected effect of finite DD-pulse width. In contrast, the lower frequency limit is primarily governed by the duration of optical repolarization rather than the decoherence time (T2_2) of NV spins. This becomes particularly crucial when the repetition (dwell) time of the sequential readout is fixed to maintain the acquisition bandwidth. The equation we provide successfully describes the tendency in the frequency dependence. In addition, at the near-optimal frequency of 1 MHz, we reached a maximum sensitivity of 229 pT/Hz\sqrt{\mathrm{Hz}} by employing the XY4-(4) DD sequence.Comment: 7 pages, 5 figure

    Quantum diamond microscopy with sub-ms temporal resolution

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    Quantum diamond magnetometers using lock-in detection have successfully detected weak bio-magnetic fields from neurons, a live mammalian muscle, and a live mouse heart. This opens up the possibility of quantum diamond magnetometers visualizing microscopic distributions of the bio-magnetic fields. Here, we demonstrate a lock-in-based wide-field quantum diamond microscopy, achieving a mean volume-normalized per pixel sensitivity of 43.9 nTμm1.5/Hz0.5\mathrm{nT\cdot\mu m^{1.5}/Hz^{0.5}}. We obtain the sensitivity by implementing a double resonance with hyperfine driving and magnetic field alignment along the orientation of the diamond. Additionally, we have demonstrated that sub-ms temporal resolution (\sim 0.4 ms) can be achieved at a micrometer scale with tens of nanotesla per-pixel sensitivity using quantum diamond microscopy. This lock-in-based diamond quantum microscopy could be a step forward in mapping functional activity in neuronal networks in micrometer spatial resolution

    Case report: Successful treatment of malignant pericardial effusion with pericardiocentesis, concurrent anti-inflammatory therapy and cancer therapy

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    Despite significant advancements in systemic anticancer therapies, cardiac tamponade remains a serious and potentially life-threatening complication in metastatic breast cancer (MBC). However, there is a paucity of comprehensive research investigating alternative management approaches, such as pericardiocentesis and anti-inflammatory therapy (AIT), to effectively address cardiac tamponade and mitigate the risk of heart failure arising from constrictive physiology (CP) in patients with MBC when traditional systemic anticancer drugs fail to yield favorable outcomes. Herein, we describe two cases of MBC with cardiac tamponade that occurred despite the administration of effective systemic anticancer drugs. In each case, pericardial effusion was detected in a patient who was undergoing palliative anticancer therapy for human epidermal growth factor receptor 2 (HER2)-positive MBC. The patients in these cases were successfully treated with pericardiocentesis and AIT (prednisolone and colchicine) for subsequent CP without substitution with their systemic anticancer drugs. Cardiac tamponade and CP are regarded as signs of advanced cancer and are associated with a worse clinical outcome in general; however, they can still be treated with an effective anticancer drug, pericardiocentesis, and management of CP by cardiooncology specialists

    Psycho-oncology in Korea: Past, present and future

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    Background: Psycho-oncology in Korea was introduced among the circle of consultation-liaison psychiatrists, in the 1990s. For almost 25 years, the field has been developing at a steady pace as the psychosocial needs of patients with cancer continue to increase. In this study, we review the history of psycho-oncology in Korea, in a chronological order, within the domains of clinical practice, research activity, training, and public policy. Main body: Before the 1990s, patients with cancer with psychiatric comorbidities were usually taken care of by consultation-liaison psychiatrists in general hospitals. In 1993, psycho-oncology was first introduced by psychiatrists. Psychologists, nurses, and social workers have also been increasingly involved in providing psychosocial care for patients with cancer. Professionals from various disciplines began to communicate, and agreed to found the Korean Psycho-Oncology Study Group (KPOSG) in 2006, the first academic society in this field. In 2009, National Cancer Center published the Recommendations for Distress Management in Patients with Cancer, which are consensus-based guidelines for Korean patients. In 2014, the KPOSG was dissolved and absorbed into a new organization, the Korean Psycho-Oncology Society (KPOS). It functions as a center of development of psycho-oncology, publishing official journals, and hosting annual conferences. There are many challenges, including, low awareness of psycho-oncology, presence of undertreated psychiatric disorders in patients with cancer, shortage of well-trained psycho-oncologists, stigma, and suicide risk. It is important to improve the cancer care system to the extent that psycho-oncology is integrated with mainstream oncology. Considering the socio-cultural characteristics of Korean cancer care, a Korean model of distress management is being prepared by the KPOS. Conclusion: This article provides an overview of the development, current issues, and future challenges of psycho-oncology in Korea. Through its long journey to overcome the many barriers and stigmas of cancer and mental illnesses, psycho-oncology is now acknowledged as an essential part of integrated supportive care in cancer. Active research and international cooperation can gradually shape the Korean model of distress management.ope

    Elevated intracellular cAMP exacerbates vulnerability to oxidative stress in optic nerve head astrocytes.

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    Glaucoma is characterized by a progressive loss of retinal ganglion cells and their axons, but the underlying biological basis for the accompanying neurodegeneration is not known. Accumulating evidence indicates that structural and functional abnormalities of astrocytes within the optic nerve head (ONH) have a role. However, whether the activation of cyclic adenosine 3',5'-monophosphate (cAMP) signaling pathway is associated with astrocyte dysfunction in the ONH remains unknown. We report here that the cAMP/protein kinase A (PKA) pathway is critical to ONH astrocyte dysfunction, leading to caspase-3 activation and cell death via the AKT/Bim/Bax signaling pathway. Furthermore, elevated intracellular cAMP exacerbates vulnerability to oxidative stress in ONH astrocytes, and this may contribute to axonal damage in glaucomatous neurodegeneration. Inhibition of intracellular cAMP/PKA signaling activation protects ONH astrocytes by increasing AKT phosphorylation against oxidative stress. These results strongly indicate that activation of cAMP/PKA pathway has an important role in astrocyte dysfunction, and suggest that modulating cAMP/PKA pathway has therapeutic potential for glaucomatous ONH degeneration

    Structural abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS)

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    AbstractPurposeThe aim of this study was to investigate cortical thickness and gray matter volume abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS). We additionally assessed the effects of comorbid attention-deficit/hyperactivity (ADHD) on these abnormalities.MethodsSurface and volumetric MR imaging data of children with newly diagnosed BCECTS (n=20, 14 males) and age-matched healthy controls (n=20) were analyzed using FreeSurfer (version 5.3.0, https://surfer.nmr.mgh.harvard.edu). An additional comparison was performed between BCECTS children with and without ADHD (each, n=8). A group comparison was carried out using an analysis of covariance with a value of significance set as p<0.01 or p<0.05.ResultsChildren with BCECTS had significantly thicker right superior frontal, superior temporal, middle temporal, and left pars triangularis cortices. Voxel-based morphometric analysis revealed significantly larger cortical gray matter volumes of the right precuneus, left orbitofrontal, pars orbitalis, precentral gyri, and bilateral putamen and the amygdala of children with BCECTS compared to healthy controls. BCECTS patients with ADHD had significantly thicker left caudal anterior and posterior cingulate gyri and a significantly larger left pars opercularis gyral volume compared to BCECTS patients without ADHD.ConclusionChildren with BCECTS have thicker or larger gray matters in the corticostriatal circuitry at the onset of epilepsy. Comorbid ADHD is also associated with structural aberrations. These findings suggest structural disruptions of the brain network are associated with specific developmental electro-clinical syndromes

    Study on National HR Competitiveness Assessment: Current Trends and Future Directions

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    2007This study attempts to develop a set of indicators to assess human resource competitiveness. To meet this purpose, the current status of the national competitiveness assessment model as well as its development process was reviewed. Also, by extracting indicators related to human resources from the national competitiveness assessment model, the strengths and weaknesses of the assessment method of national and HR competitiveness were analyzed. HR related theories were critically reviewed, and the implication of each theory was suggested. Based on these analyses, a HR competitiveness assessment model and indicators were developed.This work was financially supported by a grant (KRF-2005-005-J16701) from the Korea Research Foundation

    Theoretical Estimation of Cannulation Methods for Left Ventricular Assist Device Support as a Bridge to Recovery

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    Left ventricular assist device (LVAD) support under cannulation connected from the left atrium to the aorta (LA-AA) is used as a bridge to recovery in heart failure patients because it is non-invasive to ventricular muscle. However, it has serious problems, such as valve stenosis and blood thrombosis due to the low ejection fraction of the ventricle. We theoretically estimated the effect of the in-series cannulation, connected from ascending aorta to descending aorta (AA-DA), on ventricular unloading as an alternative to the LA-AA method. We developed a theoretical model of a LVAD-implanted cardiovascular system that included coronary circulation. Using this model, we compared hemodynamic responses according to various cannulation methods such as LA-AA, AA-DA, and a cannulation connected from the left ventricle to ascending aorta (LV-AA), under continuous and pulsatile LVAD supports. The AA-DA method provided 14% and 18% less left ventricular peak pressure than the LA-AA method under continuous and pulsatile LVAD conditions, respectively. The LA-AA method demonstrated higher coronary flow than AA-DA method. Therefore, the LA-AA method is more advantageous in increasing ventricular unloading whereas the AA-DA method is a better choice to increase coronary perfusion
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