102 research outputs found
Role of Frustration and Dimensionality in the Hubbard Model on the Stacked Square Lattice: Variational Cluster Approach
Using variational cluster approach, we study influence of frustration and
dimensionality on magnetic properties in the ground state of Hubbard model on a
stacked square lattice in the large region (U/t=10), by changing the
next-nearest-neighbor hopping, , and the interlayer hopping,
. For small with
, antiferromagnetic long-range order appears
at small , and collinear magnetic long-range
order at large . They are separated by a
paramagnetic Mott insulating state which appears in the parameter region
. For large
, the paramagnetic Mott insulating state disappears
and a direct transition between antiferromagnetic state and collinear magnetic
state occurs at . We also find that the
transition from the antiferromagnetic state to the paramagnetic Mott insulating
state is of the second-order and that from the collinear magnetic state to the
paramagnetic Mott insulating or the antiferromagnetic state is of the
first-order.Comment: 7 pages, 6 figures, submitted to Physical Review
DNA Damage in Rheumatoid Arthritis: An Age-Dependent Increase in the Lipid Peroxidation-Derived DNA Adduct, Heptanone-Etheno-2′-Deoxycytidine
Objective. To evaluate what types of DNA damages are detected in rheumatoid arthritis (RA). Methods. The DNA adducts such as 8-oxo-hydroxy-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG), 1,N6-etheno-2′-deoxyadenosine (εdA), and heptanone-etheno-2′-deoxycytidine (HεdC) in genomic DNAs, derived from whole blood cells from 46 RA patients and 31 healthy controls, were analyzed by high-performance liquid chromatography tandem mass spectrometry, and their levels in RA patients and controls were compared. In addition, correlation between DNA adducts and clinical parameters of RA was analyzed. Results. Compared with controls, the levels of HεdC in RA were significantly higher (P<0.0001) and age dependent (r = 0.43, P < 0.01), while there was no significant difference in 8-oxo-dG and εdA accumulation between RA patients and controls. HεdC levels correlated well with the number of swollen joints (r = 0.57, P < 0.0001) and weakly with the number of tender joints (r = 0.26, P = 0.08) of RA patients, while they did not show a significant association with serological markers such as C-reactive protein and matrix metalloproteinase 3. Conclusion. These findings indicate that HεdC may have some influence on the development of RA and/or its complications
Impact of transport pathways on the time from symptom onset of ST-segment elevation myocardial infarction to door of coronary intervention facility
AbstractBackgroundReducing total ischemic time is important in achieving better outcome in ST-segment elevation myocardial infarction (STEMI). Although the onset-to-door (OTD) time accounts for a large portion of the total ischemic time, factors affecting prolongation of the OTD time are not established.PurposeThe purpose of this study was to determine the impact of transport pathways on OTD time in patients with STEMI.Methods and subjectsWe retrospectively studied 416 STEMI patients who were divided into 4 groups according to their transport pathways; Group 1 (n=41): self-transportation to percutaneous coronary intervention (PCI) facility; Group 2 (n=215): emergency medical service (EMS) transportation to PCI facility; Group 3 (n=103): self-transportation to non-PCI facility; and Group 4 (n=57): EMS transportation to non-PCI facility. OTD time was compared among the 4 groups.Essential resultsMedian OTD time for all groups combined was 113 (63–228.8)min [Group 1, 145 (70–256.5); Group 2, 71 (49–108); Group 3, 260 (142–433); and Group 4, 184 (130–256)min]. OTD time for EMS users (Groups 2 and 4) was 138min shorter than non-EMS users (Groups 1 and 3). Inter-hospital transportation (Groups 3 and 4) prolonged OTD by a median of 132min compared with direct transportation to PCI facility (Groups 1 and 2). Older age, history of myocardial infarction, prior PCI, shock at onset, high Killip classification, and high GRACE Risk Score were significantly more frequent in EMS users.Principal conclusionsSelf-transportation without EMS and inter-hospital transportation were significant factors causing prolongation of the OTD time. Approximately 35% of STEMI patients did not use EMS and 21% of patients were transported to non-PCI facilities even though they called EMS. Awareness in the community as well as among medical professionals to reduce total ischemic time of STEMI is necessary; this involves educating the general public and EMS crews
PETREL: Platform for Extra and Terrestrial Remote Examination with LCTF
A small satellite ”PETREL” for UV astronomy and remote sensing with ”tunable” multi-spectral cameras conducted by an academia-industrial collaboration is presented. This project was originally proposed by an astronomer who desired a satellite for exploration of explosive objects in ultraviolet. To avoid the earthshine the astronomical observations are scheduled only in the nighttime. To utilize the daytime more electively we conceived a plan of ”satellite sharing” with the industrial collaborators, that can also reduce the developing cost drastically. The daytime mission is spectroscopy that is one of the potential fields in terms of data business, because that can provide chemical and biological information on the surface of the earth. We employ multi-spectral cameras making use of liquid crystal tunable filters (LCTFs) that enable adaptive observations at the optimized wave-bands for each targets. In 2020, this remote-sensing project and ultraviolet astronomy mission were accepted as a small satellite project of JAXA’s Innovative Satellite Technology Demonstration program and as an ISAS/JAXA’s small-scale program, respectively. This satellit
Novel, Objective, Multivariate Biomarkers Composed of Plasma Amino Acid Profiles for the Diagnosis and Assessment of Inflammatory Bowel Disease
BACKGROUND: Inflammatory bowel disease (IBD) is a chronic intestinal disorder that is associated with a limited number of clinical biomarkers. In order to facilitate the diagnosis of IBD and assess its disease activity, we investigated the potential of novel multivariate indexes using statistical modeling of plasma amino acid concentrations (aminogram). METHODOLOGY AND PRINCIPAL FINDINGS: We measured fasting plasma aminograms in 387 IBD patients (Crohn's disease (CD), n = 165; ulcerative colitis (UC), n = 222) and 210 healthy controls. Based on Fisher linear classifiers, multivariate indexes were developed from the aminogram in discovery samples (CD, n = 102; UC, n = 102; age and sex-matched healthy controls, n = 102) and internally validated. The indexes were used to discriminate between CD or UC patients and healthy controls, as well as between patients with active disease and those in remission. We assessed index performances using the area under the curve of the receiver operating characteristic (ROC AUC). We observed significant alterations to the plasma aminogram, including histidine and tryptophan. The multivariate indexes established from plasma aminograms were able to distinguish CD or UC patients from healthy controls with ROC AUCs of 0.940 (95% confidence interval (CI): 0.898-0.983) and 0.894 (95%CI: 0.853-0.935), respectively in validation samples (CD, n = 63; UC, n = 120; healthy controls, n = 108). In addition, other indexes appeared to be a measure of disease activity. These indexes distinguished active CD or UC patients from each remission patients with ROC AUCs of 0.894 (95%CI: 0.853-0.935) and 0.849 (95%CI: 0.770-0.928), and correlated with clinical disease activity indexes for CD (r(s) = 0.592, 95%CI: 0.385-0.742, p<0.001) or UC (r(s) = 0.598, 95%CI: 0.452-0.713, p<0.001), respectively. CONCLUSIONS AND SIGNIFICANCE: In this study, we demonstrated that established multivariate indexes composed of plasma amino acid profiles can serve as novel, non-invasive, objective biomarkers for the diagnosis and monitoring of IBD, providing us with new insights into the pathophysiology of the disease
Changes in expression levels of ERCC1, DPYD, and VEGFA mRNA after first-line chemotherapy of metastatic colorectal cancer: results of a multicenter study
Our previous study showed that administering oxaliplatin as first-line chemotherapy increased ERCC1 and DPD levels in liver colorectal cancers (CRCs) metastases. Second, whether the anti-VEGF monoclonal antibody bevacizumab alters tumoral VEGFA levels is unknown. We conducted this multicenter observational study to validate our previous findings on ERCC1 and DPD, and clarify the response of VEGFA expression to bavacizumab administration. 346 CRC patients with liver metastases were enrolled at 22 Japanese institutes. Resected liver metastases were available for 175 patients previously treated with oxaliplatin-based chemotherapy (chemotherapy group) and 171 receiving no previous chemotherapy (non-chemotherapy group). ERCC1, DPYD, and VEGFA mRNA levels were measured by real-time RT-PCR. ERCC1 mRNA expression was significantly higher in the chemotherapy group than in the non-chemotherapy group (P = 0.033), and were significantly correlated (Spearman\u27s correlation coefficient = 0.42; P < 0.0001). VEGFA expression level was higher in patients receiving bevacizumab (n = 51) than in those who did not (n = 251) (P = 0.007). This study confirmed that first-line oxaliplatin-based chemotherapy increases ERCC1 and DPYD expression levels, potentially enhancing chemosensitivity to subsequent therapy. We also found that bevacizumab induces VEGFA expression in tumor cells, suggesting a biologic rationale for extending bevacizumab treatment beyond first progression
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