1,191 research outputs found

    Admittance and noise in an electrically driven nano-structure: Interplay between quantum coherence and statistics

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    We investigate the interplay between the quantum coherence and statistics in electrically driven nano-structures. We obtain expression for the admittance and the current noise for a driven nano-capacitor in terms of the Floquet scattering matrix and derive a non-equilibrium fluctuation-dissipation relation. As an interplay between the quantum phase coherence and the many-body correlation, the admittance has peak values whenever the noise power shows a step as a function of near-by gate voltage. Our theory is demonstrated by calculating the admittance and noise of driven double quantum dots

    Development of Threat Evaluation Tool for Distributed Network Environment

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    Current information protection systems only detect and warn against individual intrusion, and are not able to provide a collective and synthesized alert message. In this paper, we propose a new Meta-IDS system which is called ``SIA System''. The SIA system can filter redundant alert messages, analyze mixed attacks using correlation alert messages from each sensor and respond to security threats quickly, after classifying them into one of four different statuses. Then we implement the SIA system and test the efficiency of it in the managed networks. Thus we confirm that the SIA system enables security managers to deal with security threats efficiently

    Management Trend for Unstable Pelvic Bone Fractures in Regional Trauma Centers: Multi-Institutional Study in the Republic of Korea

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    Purpose In the Republic of Korea, the use of trauma centers was recently adopted and is expected to have better outcome for severely injured patients. This study aimed to evaluate the clinical outcomes and treatment methods for unstable pelvic bone fractures in trauma centers. Methods The annual number of patients, clinical outcomes, and treatment methods of unstable pelvic bone fractures in three trauma centers from 2016 to 2020 were retrospectively reviewed. The patients were dichotomized into survivors and deceased, and demographic data, treatment, and clinical outcomes were compared. Multivariable analysis was performed to identify the factors associated with survival. Results Among 237 patients, 101 (42.6%) were deceased. Mortality was lower in the later period (2019–2020) compared with the early period (2016–2018; 33.6% vs. 50.0%, p = 0.011). Direct admission of an increasing number of patients to trauma centers reduced prehospital time. Although the use of angioembolization in treating pelvic bone fracture (p < 0.001), and the use of other treatment methods did not change significantly (2016–2020). Lower age, lowest systolic blood pressure in the trauma bay, and higher lactate level, international normalized ratio, the amount of packed red blood cell transfusion at 24 hours were positively associated with mortality in the multivariate analysis. Conclusion Increasingly more patients with unstable pelvic bone fracture were admitted to trauma centers; mortality improved. Angioembolization increased significantly and multi-disciplinary modality for early bleeding control was still essential

    Effect of rhBMP-2 applied with a 3D-printed titanium implant on new bone formation in rabbit calvarium

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    Objective: This study sought to compare the biocompatibility of a three-dimensional (3D)-printed titanium implant with a conventional machined titanium product, as well as the effect of such implant applied with recombinant human Bone Morphogenetic Protein Type 2 (rhBMP-2) for guided bone regeneration.&nbsp;Methodology: Disk-shaped titanium specimens fabricated either by the conventional machining technique or by the 3D-printing technique were compared by MC3T3-E1 cells cytotoxicity assay. New bone formation was evaluated using a rapid prototype titanium cap applied to the calvaria of 10 rabbits, which were divided into two groups: one including an atelopeptide collagen plug on one side of the cap (group I) and the other including a plug with rhBMP-2 on the other side (group II). At six and 12 weeks after euthanasia, rabbits calvaria underwent morphometric analysis through radiological and histological examination.&nbsp;Results: Through the cytotoxicity assay, we identified a significantly higher number of MC3T3-E1 cells in the 3D-printed specimen when compared to the machined specimen after 48 hours of culture. Moreover, morphometric analysis indicated significantly greater bone formation at week 12 on the side where rhBMP-2 was applied when evaluating the upper portion immediately below the ca p. Conclusion: The results suggest that 3D-printed titanium implant applied with rhBMP-2 enables new bone formation

    Journey of a Swallowed Toothbrush to the Colon

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    Toothbrush swallowing is a rare event. Because no cases of spontaneous passage have been reported, prompt removal is recommended to prevent the development of complications. Most swallowed toothbrushes have been found in the esophagus or the stomach of affected patients, and there has been no previously reported case of a toothbrush in the colon. Here, we report a case of a swallowed toothbrush found in the ascending colon that caused a fistula between the right colon and the liver, with a complicating small hepatic abscess. This patient was successfully managed using exploratory laparotomy. To our knowledge, this is the first documented case of a swallowed toothbrush found in the colon

    Cyclooxygenase-2 and p53 Expression as Prognostic Indicators in Conventional Renal Cell Carcinoma

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    The aim of this study was to investigate the relationship of cyclooxygenase (COX)-2 and p53 expression with prognosis in patients with conventional renal cell carcinoma (RCC). Formalin-fixed, paraffin-embedded tissue sections of conventional RCC from 92 patients, who had undergone radical nephrectomy, were examined for COX-2 and p53 expression by immunohistochemistry and compared with clinicopathological variables. The COX-2 expression significantly correlated only with tumor size (p=0.049), whereas the p53 expression profoundly correlated with the TNM stage (p=0.024), M stage (p=0.001), and metastasis (synchronous or metachronous; p=0.004). The COX-2 overexpression did not significantly associate with p53 positivity (p=0.821). The survival rate of patients correlated with the p53 expression (p<0.0001) but not with the COX-2 expression (p=0.7506). Multivariate analyses indicated that tumor size, M stage, and p53 expression were independent prognostic factors for cancer-specific survival. The COX-2 expression was not an independent factor. These results show that the increased expression of p53 was associated with metastasis and a worse prognosis in conventional RCC, which suggests that p53 might have played an important role in the progression of conventional RCC. The increased expression of COX-2 was associated only with tumor size, but may not be an important prognostic factor in conventional RCC. No association was observed between COX-2 overexpression and p53 positivity in conventional RCC

    Neural Correlates of Transient Mal de Debarquement Syndrome: Activation of Prefrontal and Deactivation of Cerebellar Networks Correlate With Neuropsychological Assessment

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    Background: Mal de debarquement syndrome (MdDS) is characterized by a subjective perception of self-motion after exposure to passive motion, mostly after sea travel. A transient form of MdDS (t-MdDS) is common in healthy individuals without pathophysiological certainty. In the present cross-sectional study, the possible neuropsychiatric and functional neuroimaging changes in local fishermen with t-MdDS were evaluated. Methods: The present study included 28 fishermen from Buan County in South Korea; 15 (15/28, 53.6%) participants experienced t-MdDS for 1–6 h, and 13 were asymptomatic (13/28, 46.4%). Vestibular function tests were performed using video-oculography, the video head impulse test, and ocular and cervical vestibular-evoked myogenic potentials. Visuospatial function was also assessed by the Corsi block test. Brain imaging comprised structural MRI, resting-state functional MRI, and [18F]FDG PET scans. Results: The results of vestibular function tests did not differ between the fishermen with and those without t-MdDS. However, participants with t-MdDS showed better performance in visuospatial memory function than those without t-MdDS (6.40 vs. 5.31, p-value = 0.016) as determined by the Corsi block test. Structural brain MRIs were normal in both groups. [18F]FDG PET showed a relative hypermetabolism in the bilateral occipital and prefrontal cortices and hypometabolism in the vestibulocerebellum (nodulus and uvula) in participants with t-MdDS compared to those without t-MdDS. Resting-state functional connectivities were significantly decreased between the vestibular regions of the flocculus, superior temporal gyrus, and parietal operculum and the visual association areas of the middle occipital gyrus, fusiform gyrus, and cuneus in participants with t-MdDS. Analysis of functional connectivity of the significant regions in the PET scans revealed decreased connectivity between the prefrontal cortex and visual processing areas in the t-MdDS group. Conclusion: Increased visuospatial memory, altered metabolism in the prefrontal cortex, visual cognition cortices, and the vestibulocerebellum, and decreased functional connectivity between these two functional areas might indicate reductions in the integration of vestibular input and enhancement of visuospatial attention in subjects with t-MdDS. Current functional neuroimaging similarities from transient MdDS via chronic MdDS to functional dizziness and anxiety disorders suggest a shared mechanism of enhanced self-awareness as a kind of continuum or as overlap disorders

    Impact of low-density lipoprotein cholesterol on progression of aortic valve sclerosis and stenosis

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    BackgroundLittle research has been assessed atherosclerotic risk factors at various stages of calcific aortic valve disease. This study sought to determine risk factors of patients with aortic valve sclerosis (AVS) and mild to moderate aortic stenosis (AS).MethodsThe study included 1,007 patients diagnosed with AVS or mild to moderate AS according to echocardiographic criteria. Patients were identified as a rapid progression group if the annualized difference in peak aortic jet velocity (Vmax) between two echocardiographic examinations was &gt;0.08 m/s/yr in AVS and &gt;0.3 m/s/yr in AS, respectively. We used multivariable logistic regression analyses to assess the factors associated with rapid disease progression or progression to severe AS.ResultsAmong 526 AVS patients, higher LDL-C level (odds ratio [OR] 1.22/per 25 mg/dl higher LDL-C, 95% confidence interval [CI] 1.05–1.43) was significantly associated with rapid disease progression. Compared to patients with LDL-C level &lt;70 mg/dl, the adjusted OR for rapid progression were 1.32, 2.15, and 2.98 for those with LDL-C level of 70–95 mg/dl, 95–120 mg/dl, and ≥120 mg/dl, respectively. Among 481 mild to moderate AS patients, the baseline Vmax (OR 1.79/per 0.5 m/s higher Vmax, 95% CI 1.18–2.70) was associated with rapid progression. Compared to patients with Vmax 2.0–2.5 m/s, the adjusted OR for rapid progression were 2.47, 2.78, and 3.49 for those with Vmax of 2.5–3.0 m/s, 3.0–3.5 m/s, and 3.5–4.0 m/s, respectively. LDL-C and baseline Vmax values were independently associated with progression to severe AS.ConclusionAtherosclerotic risk factors such as LDL-C were significantly associated with the rapid progression in AVS and baseline Vmax was important in the stage of mild to moderate AS

    Apoptotic Pattern of Cochlear Outer Hair Cells and Frequency-specific Hearing Threshold Shift in Noise-exposed BALB/c Mice

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    ObjectivesApoptosis of outer hair cell (OHC) can be identified through nuclear staining by specific nuclear changes. The change of filamentous actin (F-actin) is also involved in early cell death process. The study was designed to investigate OHC death along the whole length of the organ of Corti.MethodsBALB/c hybrid mice were used in this study. The noise group was exposed to white noise of 120 dB SPL for 3 hr per day for 3 consecutive days. The tone burst auditory brainstem response (ABR) test was conducted and cochleas from each group were obtained for the immunostaining of FITC phalloidin for F-actin and propidium iodide (PI) for nuclei.ResultsABR threshold of the noise group significantly increased after noise exposure (P<0.001). No threshold shift was found in the control group. Threshold shift of the noise group constantly increased from 4 to 16 kHz, but threshold shifts at 16 kHz and 32 kHz were similar. Patterns of OHC staining were subclassified as FITC+PI- cells, FITC+ PI+ cells, FITC-PI+ cells and missing cells. Proportion of normal live OHCs (FITC+PI-) rapidly decreased from the apex to the base. In the basal turn, FITC-PI+ cells and vacancy OHC (missing cells) were observed easily. Apoptotic and missing cells were most abundant at 60% of the whole length of the Corti organ.ConclusionWe could subclassify morphologic changes in OHC death after noise exposure. Quantitative changes in OHCs along the whole Corti organ showed a plateau pattern similar to that of a frequency-specific threshold shift
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