Novel CNT Supported Molybdenum Catalyst for Detection of L-Cysteine in Its Natural Environment

In this study, novel carbon nanotube-supported Mo (Mo/CNT) catalysts were prepared with the sodium borohydride reduction method for the detection of L-cysteine (L-Cys, L-C). Mo/CNT catalysts were characterized with scanning electron microscopy with elemental dispersion X-ray (EDX-SEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectrometry (UV-vis), temperature-programmed reduction (TPR), temperature programmed oxidation (TPO), and temperature-programmed desorption (TPD) techniques. The results of these advanced surface characterization techniques revealed that the catalysts were prepared successfully. Electrochemical measurements were employed to construct a voltammetric L-C sensor based on Mo/CNT catalyst by voltammetric techniques such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Further measurements were carried out with electrochemical impedance spectroscopy (EIS). Mo/CNT/GCE exhibited excellent performance for L-C detection with a linear response in the range of 0–150 µM, with a current sensitivity of 200 mA/μM cm2 (0.0142 μA/μM), the lowest detection limit of 0.25 μM, and signal-to-noise ratio (S/N = 3). Interference studies showed that the Mo/CNT/GCE electrode was not affected by D-glucose, uric acid, L-tyrosine, and L-trytophane, commonly interfering organic structures. Natural sample analysis was also accomplished with acetyl L-C. Mo/CNT catalyst is a promising material as a sensor for L-C detection.

How robust are findings of pairwise and network meta-analysis in the presence of missing participant outcome data?

Background To investigate the prevalence of robust conclusions in systematic reviews addressing missing (participant) outcome data via a novel framework of sensitivity analyses and examine the agreement with the current sensitivity analysis standards. Methods We performed an empirical study on systematic reviews with two or more interventions. Pairwise meta-analyses (PMA) and network meta-analyses (NMA) were identified from empirical studies on the reporting and handling of missing outcome data in systematic reviews. PMAs with at least three studies and NMAs with at least three interventions on one primary outcome were considered eligible. We applied Bayesian methods to obtain the summary effect estimates whilst modelling missing outcome data under the missing-at-random assumption and different assumptions about the missingness mechanism in the compared interventions. The odds ratio in the logarithmic scale was considered for the binary outcomes and the standardised mean difference for the continuous outcomes. We calculated the proportion of primary analyses with robust and frail conclusions, quantified by our proposed metric, the robustness index (RI), and current sensitivity analysis standards. Cohen’s kappa statistic was used to measure the agreement between the conclusions derived by the RI and the current sensitivity analysis standards. Results One hundred eight PMAs and 34 NMAs were considered. When studies with a substantial number of missing outcome data dominated the analyses, the number of frail conclusions increased. The RI indicated that 59% of the analyses failed to demonstrate robustness compared to 39% when the current sensitivity analysis standards were employed. Comparing the RI with the current sensitivity analysis standards revealed that two in five analyses yielded contradictory conclusions concerning the robustness of the primary analysis results. Conclusions Compared with the current sensitivity analysis standards, the RI offers an explicit definition of similar results and does not unduly rely on statistical significance. Hence, it may safeguard against possible spurious conclusions regarding the robustness of the primary analysis results.

Динамическая коррекция чувствительности дефектоскопических каналов при высокоскоростном контроле рельсов

The article is aimed at increasing the reliability of high-speed ultrasonic monitoring of long-dimensional objects, in particular, railway rails. The technical documentation for the control does not take into account the features of high-speed rail monitoring, is focused on compliance with the initially set parameters and cannot provide the required reliability of defect detection. The factors that manifest themselves at high scanning speeds and negatively affect the quality of control are considered. Most of these factors cannot be quantified and accounted for in order to adjust the control parameters. An estimate of the number of undetected defects was made when working according to current documents. To ensure reliable control at high speeds, it is proposed to evaluate the current sensitivity of the control using signals from standard design reflectors of the controlled object. As such reflectors, when monitoring rails, it is proposed to use standard holes in the area of bolted joints that are regularly encountered along the scanning path. An expression is obtained for determining the value of the correction of the control sensitivity depending on the scanning speed and the measured size of the signals from the holes. An algorithm for dynamic adjustment of the parameters (sensitivity) of the control is proposed, which increases the reliability of detecting defects in high-speed scanning conditions.

Fabrication and Characterization of In0.9Ga0.1O EGFET pH Sensors

In this study, the In0.9Ga0.1O sensing membrane were deposited by using the RF magnetron sputtering at room temperature and combined with commercial MOSFETs as the extended gate field effect transistor (EGFET) pH sensors. The sensing performance of the In0.9Ga0.1O EGFET pH sensors were measured and analyzed in the pH value of range between 2 to 12. In the saturation region, the pH current sensitivity calculated from the linear relationship between the and pH value was approximately 56.64 μA/pH corresponding to the linearity of 97.8%. In the linear region, the pH voltage sensitivity exhibited high sensitivity and linearity of 43.7 mV/pH and 96.3%, respectively. The In0.9Ga0.1O EGFET pH sensors were successfully fabricated and exhibited great linearity. The analyzed results indicated that the In0.9Ga0.1O was a robust material as a promising sensing membrane and effectively used for pH sensing detection application.

High Fidelity Cyclic Peptide Microarray to Diagnose Rheumatoid Arthritis

Introduction Antibodies reactive with cyclic citrullinated peptides (ACPA) have been included as a part of the ACR criteria for rheumatoid arthritis (RA) since 2010ii . However, due to the inability to capture the polydispersity of antibodies in RA without losing specificity, the ELISA assays cannot be used as definitive markers for diagnosis or prognosis. Current ELISA methods employ at most 30 unique cyclic citrullinated peptides for detection of ACPA. Apart from antibodies to citrullinated peptides, the serum from RA patients also contains antibodies to carbamylated antigens. Citrullinated and Carbamylated peptides hence show great promise for the improved diagnosis of RA. Here we tested whether a novel silicon-based combinatorial high-fidelity and high throughput cyclic peptide microarray that includes both citrullination and carbamylation modifications identifies RA with improved sensitivity compared to standard ELISA assays. Methods Using a cyclic modified peptide (CMP) library of more than 2 million sequences we tested 121 clinically diagnosed RA patients and compared binding profiles to corresponding linear epitopes and to commercially available CCP kits. Disease controls and samples from healthy individuals were also used to determine the specificity of the assay. The tests were performed using high throughput liquid handlers integrated with biochip imagers enabling high automation and a rapid turnaround time of 2.5 hrs. Since the citrulline and homocitrulline are very difficult to distinguish except by mass spectrometry, we will use the term Vibrant ACPA to include antibodies that react with either or both of these modified peptides in our assay. Results Using our CMP library, the sensitivity of RA detection was 95.04% with a specificity of 95.27% compared to linear peptides (Sensitivity 43.80% and Specificity 96.21%) and to commercial CCP kits (Sensitivity 66.94% and Specificity 89.20%). Inclusion of both citrullinated and carbamylated sequences provided increased sensitivity of testing (from 67% to 95%) as shown in Table 5. Some samples were only positive for carbamylated peptides and some only positive for citrullinated peptide indicating the importance of both peptide modifications.Conclusions These novel cyclic modified peptide (CMP) sequences have a high degree of accuracy in differentiating RA from controls, compared with standard serologic ELISA tests. Both citrullinated and carbamylated peptides are necessary for increasing the current sensitivity of RA testing. We also established here that a rigid conformation of the peptide is necessary for improved capture of antibodies by comparing cyclic and linear versions of the same peptide showing improved sensitivity with cyclisation. This high throughput pillar plate platform along with the 2 million data points generated per sample enable immune profiling on an unprecedented scale. While improved diagnostics is the primary outcome presented here, future identification of antigenic peptides that enable better prediction of prognosis and therapy would potentially improve outcomes in the affected population.

Cost effectiveness of using Faecal Immunochemical Testing (FIT) as an initial diagnostic investigation for patients with lower gastrointestinal symptoms suggestive of malignancy

Background There has been an increase in the numbers of patients presenting to primary care with suspected colorectal malignancy and subsequently an increase in demand for endoscopy. This study aims to forecast the cost of faecal immunochemical testing (FIT) compared to conventional diagnostic tests as a primary investigation for patients with symptoms suggestive of colorectal malignancy. Methods Retrospectively, 1950 patients with symptoms suggestive of colorectal malignancy who were referred through primary care and underwent investigations through standard endoscopic evaluation were included. These patients were used to forecast the cost of faecal immunochemical testing creating theoretical data for sensitivity and specificity. Outcome measures included: the number of investigations under current protocol; cost of current investigations; number of predicted false negatives and false positives and positive/negative predictive values using current sensitivity data for FIT; the cost forecast of using FIT as the primary investigation for colorectal malignancy. Results Median age was 65 (IQR 47–82) with 43.7% male and 56.3% female. A total of 1950 investigations were carried out with a diagnostic yield of 26 cancers (18 colon, 8 rectal), 138 polyps and 29 high risk adenomas (HGD ± > 10 mm). In total, £713,948 was spent on the investigations. The commonest investigation was colonoscopy totalling £533,169. The total cost per cancer diagnosis was £27,459. Sensitivity (92.1% CI 86.9–95.3) and specificity (85.8% CI 78.3–90.1) for FIT in colorectal cancer was taken from NICE and was costed via the manufacturer(s). The projected total cost of FIT for the same population using a ≥ 4 μg haemoglobin cut off was £415,680 (£15,554 per cancer). The total cost of high-risk polyps using ≥ 4 μg cut off was £404,427 (sensitivity 71.2% CI 60.5–87.2, specificity 79.8%CI 76.1–83.7) or £13,945 per polyp. Conclusions FIT is a cheaper and effective alternative test with the potential to replace current expensive methods. The forecast is based on the limited data available for sensitivity/specificity in the current literature. FIT has now been commenced for symptomatic patients in the UK and therefore sensitivity may change in the future.

STUDI PROTEKSI ELECTRIC SHOCK PADA INSTALASI RUMAH TINGGAL MENGGUNAKAN RESIDUAL CURRENT CIRCUIT BREAKER WITH INTERGRAL OVERLOAD PROTECTION

This paper offers a solution for securing a simple residential installation of the dangers of electric shock. In the introduction, the background of the importance of using a protection system in electrical installations is explained and some definitions related to electric shock and RCBO. For the part of the research method, the specifications of the RCBO used are displayed and the flow of the research is also shown. In the discussion and the results it is known that RCBO will trif if there is an overload, short circuit, and electric shock caused by direct contact with the live part. For nominal current (In) from RCBO, RCBO with a value of 6 Ampere and its current sensitivity (I∆n = 30 mA) is chosen according to the RCBO on the market.

Superflexible and Lead-Free Piezoelectric Nanogenerator as a Highly Sensitive Self-Powered Sensor for Human Motion Monitoring

For traditional piezoelectric sensors based on poled ceramics, a low curie temperature (Tc) is a fatal flaw due to the depolarization phenomenon. However, in this study, we find the low Tc would be a benefit for flexible piezoelectric sensors because small alterations of force trigger large changes in polarization. BaTi0.88Sn0.12O3 (BTS) with high piezoelectric coefficient and low Tc close to human body temperature is taken as an example for materials of this kind. Continuous piezoelectric BTS films were deposited on the flexible glass fiber fabrics (GFF), self-powered sensors based on the ultra-thin, superflexible, and polarization-free BTS-GFF/PVDF composite piezoelectric films are used for human motion sensing. In the low force region (1–9 N), the sensors have the outstanding performance with voltage sensitivity of 1.23 V N−1 and current sensitivity of 41.0 nA N−1. The BTS-GFF/PVDF sensors can be used to detect the tiny forces of falling water drops, finger joint motion, tiny surface deformation, and fatigue driving with high sensitivity. This work provides a new paradigm for the preparation of superflexible, highly sensitive and wearable self-powered piezoelectric sensors, and this kind of sensors will have a broad application prospect in the fields of medical rehabilitation, human motion monitoring, and intelligent robot.