A 1.5V CMOS Transconductor using adaptive biasing and its application

Abstract A low-voltage CMOS transconductor is designed in 0.35µm standard CMOS technology. The proposed circuit uses adaptive biasing linearization method to achieve better linearity in low voltage applications. Simulation results using HSPICE show a total harmonic distortion of -71 dB at 1.25 MHz for a 400 mV peak to peak input voltage. The total power consumption is only 45 µW with 1.5 V power supply. The circuit can be used in the implementation of membership functions or fuzzifiers in analogue and mixed-signal neuro-fuzzy systems

Proper Angle of Sono-guided Central Venous Line Insertion; a Brief Report

Introduction: Determining the proper angle for inserting central venous catheter (CV line) is of great importance for decreasing the complications and increasing success rate. The present study was designed to determine the proper angle of needle insertion for internal jugular vein catheterization. Methods: In the present case series study, candidate patients for catheterization of the right internal jugular vein under guidance of ultrasonography were studied. At the time of proper placing of the catheter, photograph was taken and Auto Cad 2014 software was used to measure the angles of the needle in the sagittal and axial planes, as well as patient’s head rotation. Result: 114 patients with the mean age of 56.96 ± 14.71 years were evaluated (68.4% male). The most common indications of catheterization were hemodialysis (55.3%) and shock state (24.6%). The mean angles of needle insertion were 102.15 ± 6.80 for axial plane, 36.21 ± 3.12 for sagittal plane and the mean head rotation angle was 40.49 ± 5.09. Conclusion: Based on the results of the present study it seems that CV line insertion under the angles 102.15 ± 6.80 degrees in the axial plane, 36.21 ± 3.12 in the sagittal plane and 40.49 ± 5.09 head rotation yield satisfactory results.

Effects of Folic Acid Supplementation on Oxidative Stress Markers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

International audience(1) Background: This systematic review and meta-analysis aimed to assess the effects of folic acid supplementation on oxidative stress markers. (2) Methods: Online database including PubMed, Scopus, Web of Science, and Cochrane were searched up to January 2021, to retrieve randomized controlled trials (RCTs) which examined the effect of folic acid supplementation on markers of oxidative stress. Meta-analyses were carried out using a random-effects model. I2 index was used to evaluate the heterogeneity of RCTs. (3) Results: Among the initial 2322 studies that were identified from electronic databases search, 13 studies involving 1013 participants were eligible. Pooled effect size from 13 studies indicated that folic acid supplementation elicits a significant rise in serum concentrations of glutathione (GSH) (WMD: 219.01 umol/L, 95% CI 59.30 to 378.71, p = 0.007) and total antioxidant capacity (TAC) (WMD: 91.70 umol/L, 95% CI 40.52 to 142.88, p < 0.001) but has no effect on serum concentrations of nitric oxide (NO) (WMD: 2.61 umol/L, 95% CI −3.48 to 8.72, p = 0.400). In addition, folic acid supplementation significantly reduced serum concentrations of malondialdehyde (MDA) (WMD: −0.13 umol/L, 95% CI −0.24 to −0.02, p = 0.020). (4) Conclusions: This meta-analysis study suggests that folic acid supplementation may significantly improve markers within the antioxidative defense system by increasing serum concentrations of GSH and TAC and decreasing serum concentrations of MDA