1,642 research outputs found

    Statistical-Mechanical Measure of Stochastic Spiking Coherence in A Population of Inhibitory Subthreshold Neurons

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    By varying the noise intensity, we study stochastic spiking coherence (i.e., collective coherence between noise-induced neural spikings) in an inhibitory population of subthreshold neurons (which cannot fire spontaneously without noise). This stochastic spiking coherence may be well visualized in the raster plot of neural spikes. For a coherent case, partially-occupied "stripes" (composed of spikes and indicating collective coherence) are formed in the raster plot. This partial occupation occurs due to "stochastic spike skipping" which is well shown in the multi-peaked interspike interval histogram. The main purpose of our work is to quantitatively measure the degree of stochastic spiking coherence seen in the raster plot. We introduce a new spike-based coherence measure MsM_s by considering the occupation pattern and the pacing pattern of spikes in the stripes. In particular, the pacing degree between spikes is determined in a statistical-mechanical way by quantifying the average contribution of (microscopic) individual spikes to the (macroscopic) ensemble-averaged global potential. This "statistical-mechanical" measure MsM_s is in contrast to the conventional measures such as the "thermodynamic" order parameter (which concerns the time-averaged fluctuations of the macroscopic global potential), the "microscopic" correlation-based measure (based on the cross-correlation between the microscopic individual potentials), and the measures of precise spike timing (based on the peri-stimulus time histogram). In terms of MsM_s, we quantitatively characterize the stochastic spiking coherence, and find that MsM_s reflects the degree of collective spiking coherence seen in the raster plot very well. Hence, the "statistical-mechanical" spike-based measure MsM_s may be used usefully to quantify the degree of stochastic spiking coherence in a statistical-mechanical way.Comment: 16 pages, 5 figures, to appear in the J. Comput. Neurosc

    Effect of a fixed-dose combination of Telmisartan/S-amlodipine on circadian blood pressure compared with Telmisartan monotherapy: TENUVA-BP study

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    Abstract Background This study evaluated the circadian efficacy of a telmisartan 40 mg/S-amlodipine 2.5 mg fixed-dose combination (Telmisartan40/S-Amlodipine2.5) compared to telmisartan 80 mg (Telmisartan80) in patients with essential hypertension who did not respond to 2–4 weeks treatment with telmisartan 40 mg. Methods Eligible patients with essential hypertension (clinic mean sitting systolic blood pressure [MSSBP] ≥140 mmHg, or ≥ 130 mmHg in those with diabetes mellitus or chronic kidney disease) were randomly assigned to Telmisartan40/S-Amlodipine2.5 or Telmisartan80 for 8 weeks. All patients underwent ambulatory BP monitoring (ABPM) at baseline and 8 weeks later. Primary endpoints were changes in mean 24-h SBP and DBP on 24-h ABPM from baseline after 8 weeks. Secondary endpoints were changes in daytime, nighttime, and morning SBP and DBP, and clinic MSSBP and MSDBP. Results A total of 316 Korean patients were enrolled, 217 patients were randomized to treatment, and 192 patients completed the study. Compared to Telmisartan80, Telmisartan40/S-Amlodipine2.5 showed significantly better reductions in 24-h mean SBP and DBP after 8 weeks. Telmisartan40/S-Amlodipine2.5 also significantly reduced secondary endpoints compared to Telmisartan80. Among 15 adverse events (7 [Telmisartan40/S-Amlodipine2.5] and 8 [Telmisartan80]), there were five adverse drug reactions; 14 events were mild, and none were identified with significant between-group differences. Conclusions Telmisartan40/S-Amlodipine2.5 was tolerable and more effective than Telmisartan80 in lowering 24-h mean ambulatory BP in patients with essential hypertension not responding adequately to Telmisartan40. Our findings support the fact that the combination of S-amlodipine with telmisartan is more appropriate than increasing the dose of telmisartan monotherapy. Trial registration ClinicalTrials.gov , NCT02231788 . Registered 4 September 2014

    Dynamic electro-optic response of graphene/graphitic flakes in nematic liquid crystals

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    Electric field induced dynamic reorientation phenomenon of graphene/graphitic flakes in homogeneously aligned nematic liquid crystal (NLC) medium has been demonstrated by optical microscopy. The flakes reorient from parallel to perpendicular configuration with respect to boundary plates of confining cells for an applied field strength of as low as tens of millivolt per micrometer. After field removal the reoriented flakes recover to their initial state with the help of relaxation of NLC. Considering flake reorientation phenomenon both in positive and negative dielectric anisotropy NLCs, the reorientation process depends on interfacial Maxwell-Wagner polarization and NLC director reorientation. We propose a phenomenological model based on electric field induced potential energy of graphitic flakes and coupling contribution of positive NLC to generate the rotational kinetic energy for flake reorientation. The model successfully explains the dependence of flake reorientation time over flake shape anisotropy, electric-field strength, and flake area. Using present operating scheme it is possible to generate dark field-off state and bright field-on state, having application potential for electro-optic light modulation devices. (C) 2013 Optical Society of Americ

    Clinical Significance of Thrombosis in an Intracardiac Blind Pouch After a Fontan Operation

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    The univentricular heart after the Fontan operation may have a blind pouch formed by the pulmonary stump or rudimentary ventricle according to the anatomy before surgery. Thrombosis in an intracardiac blind pouch of patients with a univentricular heart is a hazardous complication. Because only a few reports have described this complication, the authors evaluated the clinical significance of thrombosis in an intracardiac blind pouch of a univentricular heart. They performed a retrospective review of medical records from August 1986 to December 2007. Four patients were confirmed as having thrombosis in a pulmonary artery stump and one patient as having thrombosis in a rudimentary ventricle shown by cardiac computed tomography (CT). This represents 1.85% (5/271) of patients with ongoing regular follow-up evaluation after the Fontan operation. The median age at diagnosis was 14.2 years. Two of the five patients were taking aspirin and one patient was taking warfarin when they were identified for the development of thrombosis. None of the patients demonstrated thrombosis in the Fontan tract or venous side of the circulation. Brain magnetic resonance imaging (MRI) showed that three patients had cerebral infarction and one patient had suggestive old ischemia. Three patients with thrombus in the pulmonary stump underwent pulmonary artery stump thrombectomy and pulmonary valve obliteration. One patient with thrombus in the rudimentary ventricle underwent ventricular septal defect (VSD) closure with thrombectomy. Thrombus in a blind pouch could cause systemic thromboembolism despite little blood communication. Therefore, surgical modification of the pulmonary stump and VSD closure of the rudimentary ventricle are required to reduce the risk of later thrombus formation. Clinicians should not overlook the possibility of thrombus in a ligated pulmonary artery stump or a rudimentary ventricle after the Fontan operation, which may increase the risk of embolic stroke for patients with single-ventricle physiology

    Retrospective analyses of cisplatin-based doublet combination chemotherapy in patients with advanced gastric cancer

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    <p>Abstract</p> <p>Backgrounds</p> <p>Cisplatin-based chemotherapy, in combination with fluoropyrimidines or taxanes, have demonstrated efficacy against advanced gastric cancer (AGC). This retrospective study was performed with the data obtained from our cancer chemotherapy registry and eight another cancer centers.</p> <p>Methods</p> <p>In 2008, a total of 283 AGC patients were treated with cisplatin-based doublet chemotherapy in the first-line setting: capecitabine plus cisplatin (XP, n = 77), S-1 plus cisplatin (SP, n = 97), taxanes (docetaxel, paclitaxel) plus cisplatin (TP, n = 72), and 5-fluorouracil plus platinum (FP, n = 37). The primary endpoint of this study was overall survival (OS) and the secondary endpoints were safety, response rate and progression-free survival (PFS).</p> <p>Results</p> <p>The median age was 54 years with a range of 28-78 years and median delivered number of chemotherapy cycles were XP: 4, SP: 5, TP: 5 and FP: 5, respectively. Objective tumor responses (38%; 95% CI, 32-43%) were 40% for XP, 42% for SP, 36% for DP, and 24% for FP. The estimated median PFS was 4.5 months (95% CI, 3.6-5.4 months) and the median OS was 12.3 months (95% CI, 10.8-13.7 months). No statistically significant difference was found between each regimen used as first-line chemotherapy. At multivariate analysis, independent prognostic parameters for OS were prior gastrectomy, peritoneal dissemination, performance status and hemoglobin level</p> <p>Conclusion</p> <p>All of the cisplatin-based doublet chemotherapy regimens appear to be active as first-line chemotherapy for AGC. With better patient selection according to clinical parameters and molecular markers, clinical outcomes of AGC patients in first-line setting can be improved.</p

    SINE indel polymorphism of AGL gene and association with growth and carcass traits in Landrace × Jeju black pig F2 population

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    Genetic polymorphisms in the glycogen debrancher enzyme (AGL) gene were assessed with regard to their association with growth and carcass traits in the F2 population crossbred Landrace and Jeju (Korea) Black pig. Three genotypes representing the insertion and/or deletion (indel) polymorphisms of short interspersed nuclear element were detected at frequencies of 0.278 (L/L), 0.479 (L/S), and 0.243 (S/S), respectively. The AGL S allele-containing pigs evidenced significantly heavier body weights at birth, the 3rd week, 10th week, and 20th week during developmental stages and higher average daily gains during the late period than were noted in the L/L homozygous pigs (P < 0.05), respectively. However, average daily gains during the early period were not significantly associated with genotype distribution (P > 0.05). With regard to the carcass traits, the S allele pigs (S/-) evidenced significantly heavier carcass weights and thicker backfat than was measured in L/L homozygous pigs (P < 0.05). However, body lengths, meat color, and marbling scores were all found not to be statistically significant (P > 0.05). Consequently, the faster growth rate during the late period and backfat deposition rather than intramuscular fat deposition cause differences in pig productivity according to genotypes of the AGL gene. These findings indicate that the AGL genotypes may prove to be useful genetic markers for the improvement of Jeju Black pig-related crossbreeding systems

    SERPINB3 in the Chicken Model of Ovarian Cancer: A Prognostic Factor for Platinum Resistance and Survival in Patients with Epithelial Ovarian Cancer

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    Serine protease inhibitors (SERPINs) appear to be ubiquitously expressed in a variety of species and play important roles in pivotal physiological processes such as angiogenesis, immune responses, blood coagulation and fibronolysis. Of these, squamous cell carcinoma antigen 1 (SCCA1), also known as a SERPINB3, was first identified in squamous cell carcinoma tissue from the cervix of women. However, there is little known about the SERPINB3 expression in human epithelial ovarian cancer (EOC). Therefore, in the present study, we investigated the functional role of SERPINB3 gene in human EOC using chickens, the most relevant animal model. In 136 chickens, EOC was found in 10 (7.4%). SERPINB3 mRNA was induced in cancerous, but not normal ovaries of chickens (P<0.01), and it was abundant only in the glandular epithelium of cancerous ovaries of chickens. Further, several microRNAs, specifically miR-101, miR-1668 and miR-1681 were discovered to influence SERPINB3 expression via its 3'-UTR which suggests that post-transcriptional regulation influences SERPINB3 expression in chickens. SERPINB3 protein was localized predominantly to the glandular epithelium in cancerous ovaries of chickens, and it was abundant in the nucleus of both chicken and human ovarian cancer cell lines. In 109 human patients with EOC, 15 (13.8%), 66 (60.6%) and 28 (25.7%) patients showed weak, moderate and strong expression of SERPINB3 protein, respectively. Strong expression of SERPINB3 protein was a prognostic factor for platinum resistance (adjusted OR; odds ratio, 5.94; 95% Confidence Limits, 1.21-29.15), and for poor progression-free survival (PFS; adjusted HR; hazard ratio, 2.07; 95% CI; confidence interval, 1.03-4.41). Therefore, SERPINB3 may play an important role in ovarian carcinogenesis and be a novel biomarker for predicting platinum resistance and a poor prognosis for survival in patients with EOC

    Protective Effect of Ginseng Polysaccharides on Influenza Viral Infection

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    Ginseng polysaccharide has been known to have multiple immunomodulatory effects. In this study, we investigated whether Panax ginseng polysaccharide (GP) would have a preventive effect on influenza infection. Administration of mice with GP prior to infection was found to confer a survival benefit against infection with H1N1 (A/PR/8/34) and H3N2 (A/Philippines/82) influenza viruses. Mice infected with the 2009 H1N1 virus suspended in GP solution showed moderately enhanced survival rates and lower levels of lung viral titers and the inflammatory cytokine (IL-6). Daily treatment of vaccinated mice with GP improved their survival against heterosubtypic lethal challenge. This study demonstrates the first evidence that GP can be used as a remedy against influenza viral infection

    Characteristics of greenhouse gas concentrations derived from ground-based FTS spectra at Anmyeondo, South Korea

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    Since the late 1990s, the meteorological observatory established in Anmyeondo (36.5382° N, 126.3311° E, and 30 m above mean sea level) has been monitoring several greenhouse gases such as CO_2, CH_4, N_2O, CFCs, and SF_6 as a part of the Global Atmosphere Watch (GAW) Program. A high resolution ground-based (g-b) Fourier transform spectrometer (FTS) was installed at this observation site in 2013 and has been operated within the frame work of the Total Carbon Column Observing Network (TCCON) since August 2014. The solar spectra recorded by the g-b FTS cover the spectral range 3800 to 16 000 cm^(−1) at a resolution of 0.02 cm^(−1). In this work, the GGG2014 version of the TCCON standard retrieval algorithm was used to retrieve total column average CO_2 and CH_4 dry mole fractions (XCO_2, XCH_4) and from the FTS spectra. Spectral bands of CO_2 (at 6220.0 and 6339.5 cm^(−1) center wavenumbers, CH_4 at 6002 cm^(−1) wavenumber, and O_2 near 7880 cm^(−1)) were used to derive the XCO_2 and XCH_4. In this paper, we provide comparisons of XCO_2 and XCH_4 between the aircraft observations and g-b FTS over Anmyeondo station. A comparison of 13 coincident observations of XCO_2 between g-b FTS and OCO-2 (Orbiting Carbon Observatory) satellite measurements are also presented for the measurement period between February 2014 and November 2017. OCO-2 observations are highly correlated with the g-b FTS measurements (r^2 = 0.884) and exhibited a small positive bias (0.189 ppm). Both data set capture seasonal variations of the target species with maximum and minimum values in spring and late summer, respectively. In the future, it is planned to further utilize the FTS measurements for the evaluation of satellite observations such as Greenhouse Gases Observing Satellite (GOSAT, GOSAT-2). This is the first report of the g-b FTS observations of XCO_2 species over the Anmyeondo station
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