4,217 research outputs found
Modeling of Time with Metamaterials
Metamaterials have been already used to model various exotic "optical
spaces". Here we demonstrate that mapping of monochromatic extraordinary light
distribution in a hyperbolic metamaterial along some spatial direction may
model the "flow of time". This idea is illustrated in experiments performed
with plasmonic hyperbolic metamaterials. Appearance of the "statistical arrow
of time" is examined in an experimental scenario which emulates a Big Bang-like
event.Comment: 15 pages, 4 figures, this version is accepted for publication in JOSA
Commentary on the Regulation of Viral Proteins in Autophagy Process
The ability to subvert intracellular antiviral defenses is necessary for virus to survive as its replication occurs only in the host cells. Viruses have to modulate cellular processes and antiviral mechanisms to their own advantage during the entire virus life cycle. Autophagy plays important roles in cell regulation. Its function is not only to catabolize aggregate proteins and damaged organelles for recycling but also to serve as innate immunity to remove intracellular pathogenic elements such as viruses. Nevertheless, some viruses have evolved to negatively regulate autophagy by inhibiting its formation. Even more, some viruses have employed autophagy to benefit their replication. To date, there are more and more growing evidences uncovering the functions of many viral proteins to regulate autophagy through different cellular pathways. In this review, we will discuss the relationship between viruses and autophagy and summarize the current knowledge on the functions of viral proteins contributing to affect autophagy process
Comparison of the Prevalence of Metabolic Syndrome Between the Criteria for Taiwanese and Japanese and the Projected Probability of Stroke in Elderly Hypertensive Taiwanese
SummaryBackgroundThe cutoff of abdominal circumference for metabolic syndrome (MS) defined by the Bureau of Health Promotion (BHP) of Taiwan for Taiwanese (men, 90cm; women, 80cm) and by the International Diabetes Federation (IDF) for Japanese (men, 85cm; women, 90cm) differs. This study aimed to examine the impact of this difference on the prevalence of MS and the impact of an MS diagnosis on the projected risk of stroke in hypertensive Taiwanese.MethodsMS was examined in a sample of 3,472 hypertensive patients (aged 55–80 years; 1,709 women) across Taiwan. The 10-year probability of stroke estimated from the Framingham equation was compared between MS and non-MS patients.ResultsThe prevalence of MS using the BHP criteria was 59.2% using the BHP criteria (95% confidence interval, CI, 57.6–60.8%; men, 52.5%; women, 66.1%) and 48.9% by the IDF criteria (95% CI, 47.2–50.5%; men, 61.3%; women, 36.1%). Both criteria showed that, compared with non-MS, MS has higher predicted 10-year probability of stroke (BHP, 0.153 ± 0.115 vs. 0.133 ± 0.105; IDF, 0.159 ± 0.109 vs. 0.132 ± 0.112; both p < 0.001) because of the difference in women (BHP, 0.143 ± 0.124 vs. 0.102 ± 0.091; IDF, 0.147 ± 0.121 vs. 0.118 ± 0.110; both p < 0.001) rather than men (BHP, p = 0.21; IDF, p = 0.29).ConclusionBoth criteria demonstrate that MS is highly prevalent in elderly hypertensive patients in Taiwan. Additionally in women, but not men, the predicted probability of stroke is higher in MS than in non-MS patients. The diagnosis of MS is potentially useful for identifying elderly hypertensive females with an elevated risk of stroke in Taiwan
Estimating systemic fibrosis by combining galectin-3 and ST2 provides powerful risk stratification value for patients after acute decompensated heart failure
Background: Two fibrosis biomarkers, galectin-3 (Gal-3) and suppression of tumorigenicity 2 (ST2), provide prognostic value additive to natriuretic peptides and traditional risk factors in patients with heart failure (HF). However, it is to be investigated whether their combined measurement before discharge provides incremental risk stratification for patients after acute HF.
Methods: A total of 344 patients with acute HF were analyzed with Gal-3, and ST2 measured. Patients were prospectively followed for 3.7 ± 1.3 years for deaths, and composite events (death/HF-related re-hospitalizations).
Results: The levels of Gal-3 and ST2 were only slightly related (r = 0.20, p < 0.001). The medians of Gal-3 and ST2 were 18 ng/mL and 32.4 ng/mL, respectively. These biomarkers compensated each other and characterized patients with different risk factors. According to the cutoff at median values, patients were separated into four subgroups based on high and low Gal-3 (HG and LG, respectively) and ST2 levels (HS and LS, respectively). Kaplan-Meier survival curves showed that HGHS powerfully identified patients at risk of mortality (Log rank = 21.27, p < 0.001). In multivariable analysis, combined log(Gal-3) and log(ST2) was an independent predictor. For composite events, Kaplan-Meier survival curves showed a lower event- -free survival rate in the HGHS subgroup compared to others (Log rank = 34.62, p < 0.001; HGHS vs. HGLS, Log rank = 4.00, p = 0.045). In multivariable analysis, combined log(Gal-3) and log(ST2) was also an independent predictor.
Conclusions: Combination of biomarkers involving heterogeneous fibrosis pathways may identify patients with high systemic fibrosis, providing powerful risk stratification value
AGE-BSA down-regulates endothelial connexin43 gap junctions
<p>Abstract</p> <p>Background</p> <p>Advanced glycation end products generated in the circulation of diabetic patients were reported to affect the function of vascular wall. We examined the effects of advanced glycation end products-bovine serum albumin (AGE-BSA) on endothelial connexin43 (Cx43) expression and gap-junction communication.</p> <p>Results</p> <p>In human aortic endothelial cells (HAEC) treated with a series concentrations of AGE-BSA (0-500 μg/ml) for 24 and 48 hours, Cx43 transcript and Cx43 protein were reduced in a dose dependent manner. In addition, gap-junction communication was reduced. To clarify the mechanisms underlying the down-regulation, MAPKs pathways in HAEC were examined. Both a MEK1 inhibitor (PD98059) and a p38 MAPK inhibitor (SB203580) significantly reversed the reductions of Cx43 mRNA and protein induced by AGE-BSA. Consistently, phosphorylation of ERK and p38 MAPK was enhanced in response to exposure to AGE-BSA. However, all reversions of down-regulated Cx43 by inhibitors did not restore the functional gap-junction communication.</p> <p>Conclusions</p> <p>AGE-BSA down-regulated Cx43 expression in HAEC, mainly through reduced Cx43 transcription, and the process involved activation of ERK and p38 MAPK.</p
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To Fee or Not to Fee? Satisfaction, Service Quality, and Support of an Entrance Fee of a State Park System
In the past decade, state government appropriation reductions have forced park agencies to seek other sources of revenue to support park operations. To overcome shrinking budgets, many public park agencies embrace private sector business models and investigate customer satisfaction, service quality, and user fee structures. The purpose of this study was to obtain public input regarding service quality, general satisfaction, and experience use history of state park visitation. A total of 382 Oklahoma state park users completed an online survey and were sorted into Pro-Fee (n = 200, 52%) and No-Fee (n = 182, 48%) groups for one-way multivariate analysis of variance (MANOVA) tests. The researchers found a significant difference between the two groups on service quality, but not on overall satisfaction or behavioral intention (e.g., revisit, recommending the park). When comparing Pro-Fee and No-Fee groups, researchers found no statistically significant variance in visitors’ demographics, such as gender, education level, and income, whereas the number of years that had passed since the visitors’ first visit showed a significant difference between the groups. The findings of this study provide valuable insight for discussions related to entrance fees and service fees in state park systems
Mitf-Mdel, a novel melanocyte/melanoma-specific isoform of microphthalmia-associated transcription factor-M, as a candidate biomarker for melanoma
<p>Abstract</p> <p>Background</p> <p>Melanoma incidence is on the rise and advanced melanoma carries an extremely poor prognosis. Treatment options, including chemotherapy and immunotherapy, are limited and offer low response rates and transient efficacy. Thus, identification of new melanocyte/melanoma antigens that serve as potential novel candidate biomarkers in melanoma is an important area for investigation.</p> <p>Methods</p> <p>Full length MITF-M and its splice variant cDNA were cloned from human melanoma cell line 624 mel by reverse transcription polymerase chain reaction (RT-PCR). Expression was investigated using regular and quantitative RT-PCR in three normal melanocytes (NHEM), 31 melanoma cell lines, 21 frozen melanoma tissue samples, 18 blood samples (pheripheral blood mononuclear cell; PBMC) from healthy donors and 12 non-melanoma cancer cell lines, including three breast, five glioma, one sarcoma, two kidney and one ovarian cancer cell lines.</p> <p>Results</p> <p>A novel splice variant of MITF-M, which we named MITF-Mdel, was identified. The predicted MITF-Mdel protein contains two in frame deletions, 56- and 6- amino acid deletions in exon 2 (from V32 to E87) and exon 6 (from A187 to T192), respectively. MITF-Mdel was widely expressed in melanocytes, melanoma cell lines and tissues, but almost undetectable in non-melanoma cell lines or PBMC from healthy donors. Both isoforms were expressed significantly higher in melanoma tissues than in cell lines. Two of 31 melanoma cell lines expressed only one isoform or the other.</p> <p>Conclusion</p> <p>MITF-Mdel, a novel melanocyte/melanoma-specific isoform of MITF-M, may serve as a potential candidate biomarker for diagnostic and follow-up purposes in melanoma.</p
Outcomes and prognostic factors of simple partial cystectomy for localized bladder urothelial cell carcinoma
AbstractRadical cystectomy has remained the gold standard for recurrent superficial or muscle invasive bladder tumor. However, partial cystectomy still has a role in those who reject or have contraindications for radical cystectomy. In this study, we sought to identify predictors of bladder recurrence and overall survival after simple partial cystectomy. We included 27 patients with bladder tumor who received simple partial cystectomy without pelvic lymph node dissection between March 2000 and September 2013. Adjuvant chemotherapy or radiation therapy was prescribed according to the pathological results. Parameters were compared on the basis of bladder recurrence and overall survival. During a mean follow-up time of 39 months, five patients (18.5%) experienced bladder recurrence. An older age, a higher pathological stage, positive surgical margins, and distant metastases were significant predictors of overall survival (p = 0.031, p = 0.001, p = 0.001, and p = 0.011, respectively). Meanwhile, previous bladder instillation and positive surgical margins were significant predictors of bladder recurrence (p = 0.026 and p = 0.027, respectively). The rate of consecutive distant metastases (33.3%) was almost twice the rate of bladder recurrence (18.5%), and six patients developed consecutive distant metastases without first experiencing bladder recurrence. In patients who received a simple partial cystectomy as an alternative treatment, previous bladder instillation and positive surgical margins were significant predictors of bladder recurrence. Patients with an older age, positive surgical margins, and consecutive distant metastases had worse overall survival. Partial cystectomy with routine lymph node dissection may be a better option for achieving favorable long-term outcomes
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