Design, fabrication, and experimental validation of novel flexible silicon-based dry sensors for electroencephalography signal measurements

© 2014 IEEE. Many commercially available electroencephalography (EEG) sensors, including conventional wet and dry sensors, can cause skin irritation and user discomfort owing to the foreign material. The EEG products, especially sensors, highly prioritize the comfort level during devices wear. To overcome these drawbacks for EEG sensors, this paper designs Societe Generale de Surveillance S A c(SGS)-certified, silicon-based dry-contact EEG sensors (SBDSs) for EEG signal measurements. According to the SGS testing report, SBDSs extract does not irritate skin or induce noncytotoxic effects on L929 cells according to ISO10993-5. The SBDS is also lightweight, flexible, and nonirritating to the skin, as well as capable of easily fitting to scalps without any skin preparation or use of a conductive gel. For forehead and hairy sites, EEG signals can be measured reliably with the designed SBDSs. In particular, for EEG signal measurements at hairy sites, the acicular and flexible design of SBDS can push the hair aside to achieve satisfactory scalp contact, as well as maintain low skin-electrode interface impedance. Results of this paper demonstrate that the proposed sensors perform well in the EEG measurements and are feasible for practical applications

Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

Why are nitrogen‐fixing trees rare at higher compared to lower latitudes?

Symbiotic nitrogen (N) fixation provides a dominant source of new N to the terrestrial biosphere, yet in many cases the abundance of N‐fixing trees appears paradoxical. N‐fixing trees, which should be favored when N is limiting, are rare in higher latitude forests where N limitation is common, but are abundant in many lower latitude forests where N limitation is rare. Here, we develop a graphical and mathematical model to resolve the paradox. We use the model to demonstrate that N fixation is not necessarily cost effective under all degrees of N limitation, as intuition suggests. Rather, N fixation is only cost effective when N limitation is sufficiently severe. This general finding, specific versions of which have also emerged from other models, would explain sustained moderate N limitation because N‐fixing trees would either turn N fixation off or be outcompeted under moderate N limitation. From this finding, four general hypothesis classes emerge to resolve the apparent paradox of N limitation and N‐fixing tree abundance across latitude. The first hypothesis is that N limitation is less common at higher latitudes. This hypothesis contradicts prevailing evidence, so is unlikely, but the following three hypotheses all seem likely. The second hypothesis, which is new, is that even if N limitation is more common at higher latitudes, more severe N limitation might be more common at lower latitudes because of the capacity for higher N demand. Third, N fixation might be cost effective under milder N limitation at lower latitudes but only under more severe N limitation at higher latitudes. This third hypothesis class generalizes previous hypotheses and suggests new specific hypotheses. For example, greater trade‐offs between N fixation and N use efficiency, soil N uptake, or plant turnover at higher compared to lower latitudes would make N fixation cost effective only under more severe N limitation at higher latitudes. Fourth, N‐fixing trees might adjust N fixation more at lower than at higher latitudes. This framework provides new hypotheses to explain the latitudinal abundance distribution of N‐fixing trees, and also provides a new way to visualize them. Therefore, it can help explain the seemingly paradoxical persistence of N limitation in many higher latitude forests

A novel 16-channel wireless system for electroencephalography measurements with dry spring-loaded sensors

Understanding brain function using electroencephalography (EEG) is an important issue for cerebral nervous system diseases, especially for epilepsy and Alzheimer's disease. Many EEG measurement systems are used reliably to study these diseases, but their bulky size and the use of wet sensors make them uncomfortable and inconvenient for users. To overcome the limitations of conventional EEG measurement systems, a wireless and wearable multichannel EEG measurement system is proposed in this paper. This system includes a wireless data acquisition device, dry spring-loaded sensors, and a sizeadjustable soft cap. We compared the performance of the proposed system using dry versus conventional wet sensors. A significant positive correlation between readings from wet and dry sensors was achieved, thus demonstrating the performance of the system. Moreover, four different features of EEG signals (i.e., normal, eye-blinking, closed-eyes, and teeth-clenching signals) were measured by 16 dry sensors to ensure that they could be detected in real-life cognitive neuroscience applications. Thus, we have shown that it is possible to reliably measure EEG signals using the proposed system. This paper presents novel insights into the field of cognitive neuroscience, showing the possibility of studying brain function under real-life conditions. © 2014 IEEE

Quasi-Elliptic Bandpass Frequency Selective Surface Based on Coupled Stubs-Loaded Ring Resonators

© 2013 IEEE. In this paper, a novel design of frequency-selective surface (FSS) based on coupled stubs-loaded ring resonators (SLRRs) is proposed. The proposed FSS exhibits quasi-elliptic bandpass filtering characteristic at C-band. And each unit cell of the structure is composed of two SLRRs coupled by a circular aperture. A novel method of transmission line (TL) model is proposed to investigate the operating principle of a single SLRR under normal incidence plane wave. Moreover, the operating mechanism of the proposed FSS is further researched with the aid of the equivalent circuit model (ECM) analysis method. Due to the symmetric and low-profile physical structure, the FSS keeps stable frequency response under oblique incident plane wave for both transverse electric (TE) and transverse magnetic (TM) polarizations. Finally, the designed FSS is fabricated and measured. The measured results agree well with the simulated results. The measured results indicate that the proposed FSS exhibits a dual-polarized and stable bandpass frequency response with two transmission zeros (TZs) at around 5.71 and 6.87 GHz under different incident angles up to 40°

Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

Background Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded. Methods We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis. Findings Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis. Conclusion Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice

A novel class of microRNA-recognition elements that function only within open reading frames.

MicroRNAs (miRNAs) are well known to target 3' untranslated regions (3' UTRs) in mRNAs, thereby silencing gene expression at the post-transcriptional level. Multiple reports have also indicated the ability of miRNAs to target protein-coding sequences (CDS); however, miRNAs have been generally believed to function through similar mechanisms regardless of the locations of their sites of action. Here, we report a class of miRNA-recognition elements (MREs) that function exclusively in CDS regions. Through functional and mechanistic characterization of these 'unusual' MREs, we demonstrate that CDS-targeted miRNAs require extensive base-pairing at the 3' side rather than the 5' seed; cause gene silencing in an Argonaute-dependent but GW182-independent manner; and repress translation by inducing transient ribosome stalling instead of mRNA destabilization. These findings reveal distinct mechanisms and functional consequences of miRNAs that target CDS versus the 3' UTR and suggest that CDS-targeted miRNAs may use a translational quality-control-related mechanism to regulate translation in mammalian cells

Ghrelin Attenuates the Osteoblastic Differentiation of Vascular Smooth Muscle Cells through the ERK Pathway

Vascular calcification results from osteoblastic differentiation of vascular smooth muscle cells (VSMCs) and is a major risk factor for cardiovascular events. Ghrelin is a newly discovered bioactive peptide that acts as a natural endogenous ligand of the growth hormone secretagog receptor (GHSR). Several studies have identified the protective effects of ghrelin on the cardiovascular system, however research on the effects and mechanisms of ghrelin on vascular calcification is still quite rare. In this study, we determined the effect of ghrelin on osteoblastic differentiation of VSMCs and investigated the mechanism involved using the two universally accepted calcifying models of calcifying vascular smooth muscle cells (CVSMCs) and beta-glycerophosphate (beta-GP)-induced VSMCs. Our data demonstrated that ghrelin inhibits osteoblastic differentiation and mineralization of VSMCs due to decreased alkaline phosphatase (ALP) activity, Runx2 expression, bone morphogenetic protein-2 (BMP-2) expression and calcium content. Further study demonstrated that ghrelin exerted this suppression effect via an extracellular signal-related kinase (ERK)-dependent pathway and that the suppression effect of ghrelin was time dependent and dose dependent. Furthermore, inhibition of the growth hormone secretagog receptor (GHSR), the ghrelin receptor, by siRNA significantly reversed the activation of ERK by ghrelin. In conclusion, our study suggests that ghrelin may inhibit osteoblastic differentiation of VSMCs through the GHSR/ERK pathway