Dynamic Zero Current Method to Reduce Measurement Error in Low Value Resistive Sensor Array for Wearable Electronics.

One advantage of a resistive sensor array (RSA) with shared rows (M) and shared columns (N) is the reduced number of wires from M × N + 1 to M + N which can greatly lessen the complexity and burden on wearable electronic systems. However, the drawback is the crosstalk current effect between adjacent elements, which will lead to high measurement error. Although several solutions have been reported, they mainly focus on RSAs with high resistance (≥100 Ω). There is a lack of research that addresses RSAs with resistor values below 100 Ω. Here, we introduce a new circuit design named the dynamic zero current method (DZCM) to further decrease the measurement error. From the low value RSA test with ideal resistors, the DZCM exhibits lower error than the zero potential method (ZPM). In the case of the error variation ratio of amplifier offset voltage, the DZCM has a 4%/mV (row) to 7%/mV (column) ratio, while the ZPM has an almost 25%/mV (row) to 45%/mV (column) ratio and it increases with array size.

Systemic immune-inflammation index changes predict outcome in stage III non-small-cell lung cancer patients treated with concurrent chemoradiotherapy.

Background: Although the systemic immune-inflammation index (SII) has been used to predict recurrence and survival in non-small-cell lung cancer (NSCLC) patients, the prognostic significance of change in SII (ΔSII) is unclear for stage III NSCLC patients treated with concurrent chemoradiotherapy (CCRT). In the present study we aimed to explore the association between ΔSII and the clinical outcomes of 142 patients with stage III NSCLC treated with CCRT. Methods: A total of 142 patients were included in this retrospective study. The SII values were calculated based on laboratory data regarding platelet, neutrophil and lymphocyte counts, and ΔSII was calculated using data acquired before and approximately 2 weeks after CCRT. The receiver operating characteristic curve was used to determine the optimal cut-off value for the peripheral blood inflammation index. Kaplan-Meier analysis and Cox proportional regression were used to analyze the prognostic value of ΔSII for overall survival (OS) and progression-free survival (PFS). Results: The area under the receiver operating characteristic curve for ΔSII (0.708) was larger than those for pre-CCRT SII (0.578) and post-CCRT SII (0.610). The optimal cut-off point for ΔSII was defined as 43. OS and PFS were better in patients with low ΔSII and in multivariate analysis, the ΔSII was an independent predictor of OS and PFS (p = 0.006 and p = 0.017, respectively). Conclusions: ΔSII is related to progression and death in patients with stage III NSCLC. The ΔSII can provide a detailed prognostic prediction for stage III NSCLC.

Cognition-tracking-based strategies for diagnosis and treatment of minimal hepatic encephalopathy.

Minimal hepatic encephalopathy (MHE), which shows mild cognitive impairment, is a subtle complication of cirrhosis that has been shown to affect daily functioning and quality of life. However, until 2014, relevant guidelines do not give much attention to the diagnosis and treatment of MHE, resulting in patients being ignored and denied the benefits of treatment. In this review, we summarize recent cognition-based research about (1) alteration of nerve cells, including astrocytes, microglial cells and neurons, in mild cognitive impairment in MHE; (2) comparison of methods in detecting cognitive impairment in MHE; and (3) comparison of methods for therapy of cognitive impairment in MHE. We hope to provide information about diagnosis and treatment of cognitive impairment in patients with MHE.

Integrated biochip for label-free and real-time detection of DNA amplification by contactless impedance measurements based on interdigitated electrodes.

Here, we introduce an integrated biochip which offers accurate thermal control and sensitive electrochemical detection of DNA amplification in real-time. The biochip includes a 10-µl microchamber, a temperature sensor, a heater, and a contactless impedance biosensor. A pair of interdigitated electrodes is employed as the impedance biosensor and the products of the amplification are determined directly through tracing the impedance change, without using any labels, redox indicators, or probes. Real-time monitoring of strand-displacement amplification and rolling circle amplification was successfully performed on the biochip and a detection limit of 1 nM was achieved. Amplification starting at an initial concentration of 10 nM could be discriminated from that starting at 1 nM started concentration as well as from the negative control. Since an insulation layer covers the electrodes, the electrodes are spared from erosion, hydrolysis and bubble formation on the surface, thus, ensuring a long lifetime and a high reusability of the sensor. In comparison to bench-top apparatus, our chip shows good efficiency, sensitivity, accuracy, and versatility. Our system requires only simple equipments and simple skills, and can easily be miniaturized into a micro-scale system. The system will then be suitable for a handheld portable device, which can be applied in remote areas. It covers merits such as low cost, low-power consumption, rapid response, real-time monitoring, label-free detection, and high-throughput detection.

Photopatterning of self-assembled poly (ethylene) glycol monolayer for neuronal network fabrication.

The ability to culture individual neurons and direct their connections on functional interfaces provides a platform for investigating information processing in neuronal networks. Numerous methods have been used to design ordered neuronal networks on microelectrode arrays (MEAs) for neuronal electrical activities recording. However, so far, no method has been implemented, which simultaneously provides high-resolution neuronal patterns and low-impedance microelectrode. To achieve this goal, we employed a chemical vapor-deposited, non-fouling poly (ethylene) glycol (PEG) self-assembled monolayer to provide a cell repellant background on the MEAs. Photolithography, together with plasma etching of the PEG monolayer, was used to fabricate different patterns on MEAs. No electrode performance degradation was observed after the whole process. Dissociated cortical neurons were cultured on the modified MEAs, and the patterns were maintained for more than 3 weeks. Spontaneous and evoked neuronal activities were recorded. All of the results demonstrate this surface engineering strategy allows successful patterning of neurons on MEAs, and is useful for future studies of information processing in defined neuronal networks on a chip.

Real-time monitoring of strand-displacement DNA amplification by a contactless electrochemical microsystem using interdigitated electrodes.

This paper reports the design and implementation of a contactless conductivity detection system which combines a thermal control cell, a data processing system and an electrochemical (EC) cell for label-free isothermal nucleic acid amplification and real-time monitoring. The EC cell consists of a microchamber and interdigitated electrodes as the contactless conductivity biosensor with a cover slip as insulation. In our work, contactless EC measurements, the effects of trehalose on amplification, and chip surface treatment are investigated. With the superior performance of the biosensor, the device can detect the amount of pure DNA at concentrations less than 0.1 pg µl(-1). The EC cell, integrated with a heater and a temperature sensor, has successfully implemented nicking-based strand-displacement amplification at an initial concentration of 2.5 µM and the yields are monitored directly (dismissing the use of probes or labels) on-line. This contactless detector carries important advantages: high anti-interference capability, long detector life, high reusability and low cost. In addition, the small size, low power consumption and portability of the detection cell give the system the potential to be highly integrated for use in field service and point of care applications.