Novel CCII-based Field Programmable Analog Array and its Application to a Sixth-Order Butterworth LPF

In this paper, a field programmable analog array (FPAA) is proposed. The proposed FPAA consists of seven configurable analog blocks (CABs) arranged in a hexagonal lattice such that the CABs are directly connected to each other. This structure improves the overall frequency response of the chip by decreasing the parasitic capacitances in the signal path. The CABS of the FPAA is based on a novel fully differential digitally programmable current conveyor (DPCCII). The programmability of the DPCCII is achieved using digitally controlled three-bit MOS ladder current division network. No extra biasing circuit is required to generate specific analog control voltage signals. The DPCCII has constant standby power consumption, offset voltage, bandwidth and harmonic distortions over all its programming range. A sixth-order Butterworth tunable LPF suitable for WLAN/WiMAX receivers is realized on the proposed FPAA. The filter power consumption is 5.4mW from 1V supply; it’s cutoff frequency is tuned from 5.2 MHz to 16.9 MHz. All the circuits are realized using 90nm CMOS technology from TSMC. All simulations are carried out using Cadence

ACUTE TOXICITY OF DIFFERENT SIZES OF SILVER NANOPARTICLES INTRAPERITONALLY INJECTED IN BALB/C MICE USING TWO TOXICOLOGICAL METHODS

Objective: This study aimed to evaluate the acute toxicity of intraperitoneally administrated silver nanoparticles (AgNPs) with different particle sizes in BALB/c mice.Methods: Citrate-capped AgNPs were prepared by citrate reduction method and isolated into small particles (average size 20 nm) and large particles (average size 50 nm). The median lethal dose (LD50) of 20 nm and 50 nm AgNPs was estimated using two toxicological methods, classical Dixon's up-and-down method and AOT425statPgm method for up-and-down procedure.Results: The LD50 was evaluated at the dosage level of 169 and 213.8 mg/kg, respectively for 20 nm AgNPs and at the dosage level of 354 and 391.5 mg/kg, respectively for 50 nm AgNPs. The results showed that LD50 obtained by the AOT425statPgm method was in accord with that of the Dixon's method and no significant differences between them (P = 0.06). The size 20 nm AgNPs were more toxic than the size 50 nm AgNPs. The behavioural responses and deviations were dose dependent, increasing by increasing the dose. The anatomical examinations showed that AgNPs were mainly accumulated in liver and spleen of dosed mice.Conclusion: The results suggested that the AOT425statPgm method was an efficient tool and a good alternative method for use in future acute toxicity studies.Â

New 1.5V CMOS current feedback operational amplifier

Abstract-a novel CMOS low-voltage current feedback operational amplifier (CFOA) is presented. The proposed CFOA based on a new positive second-generation current conveyor (CCII+). The new circuit allows almost a rail-to-rail input and output operation; also, it reduces the offset voltage and provides high driving current capabilities. The CFOA is operating at supply voltages of ±0.75 V with a total standby current of 338 µA. The circuit exhibits better than 10 MHz bandwidth and ±1mA current drive capability. PSpice simulation results are given using 0.35µm technology for the proposed CFOA

Hydrophilic nanosilica as a new larvicidal and molluscicidal agent for controlling of major infectious diseases in Egypt

Aim: This research was conducted to evaluate the molluscicidal and mosquitocidal efficacy of silica nanoparticles in the eradication of the larvae and pupa of malaria and filariasis vector as well as vectors of rift-valley fever virus (Culex pipiens); Schistosoma mansoni vector (Biomphlaria alexandrina (snail and egg masses)). Materials and Methods: Hydrophilic nanosilica particles (NSPs) were characterized using transmission electron microscope during the preliminary part of the study; the stages were exposed to upgrade concentrations of NSP from 50 to 1200 ppm each for 24-36 h exposure time. The highly effective concentrations were re-evaluated at lower exposure time as 3, 6, and 12 h. Results: Lethal concentration (LC50) and LC90 versus mosquito larvae were (350 ppm/24 h and 1400 ppm/24 h, respectively). C. pipiens pupae proved slight high tolerance versus the effect of these nanoparticles as the two previous doses increased to 680 ppm/6 h and 1300 ppm/24 h. The LC50 and LC90 versus B. alexandrina were increased to 590 ppm/6 h and 980 ppm/48 h, respectively. Moreover, the embryonated snail egg masses appear more susceptible to the toxic effect of these nanoparticles than the non-embryonated eggs as the LC50 and LC90 were increased to 1450 ppm/12 h and 1250 ppm/48 h, respectively, for embryonated eggs, and it was 1400 ppm/24 h and 1890 ppm/48 h, respectively, for non-embryonated one. Conclusion: The results open a new field for controlling the infectious diseases through eradication of their vectors by the way that avoids the resistance recorded from the successive chemical application in this field

Mechanical Characterization of Cryomilled Al Powder Consolidated by High-Frequency Induction Heat Sintering

In the present investigation, an aluminum powder of 99.7% purity with particle size of ~45 µm was cryomilled for 7 hours. The produced powder as characterized by scanning, transmission electron microscopy, and X-ray diffraction gave a particle size of ~1 µm and grain (crystallite) size of 23±6 nm. This powder, after degassing process, was consolidated using high-frequency induction heat sintering (HFIHS) at various temperatures for short periods of time of 1 to 3 minutes. The present sintering conditions resulted in solid compact with nanoscale grain size (<100 nm) and high compact density. The mechanical properties of a sample sintered at 773 K for 3 minutes gave a compressive yield and ultimate strength of 270 and 390 MPa, respectively. The thermal stability of grain size nanostructured compacts is in agreement with the kinetics models based on the thermodynamics effects

Dual buoyant/mucoadhesive macroporous polypropylene microparticles for gastric delivery of repaglinide

Preparation and characterization of dual buoyant/mucoadhesive polypropylene microparticles (MPs) loaded with repaglinide (REP) for gastric drug delivery in order to augment the weak mucoadhesion in the stomach.Porous foam powder MPs were prepared using coating polymers with variable permeability (Eudragit L100, Eudragit RSPO) alone or in combination by the soaking method. Thiolated Eudragit L100 (Eudragit L100-SH) was also synthesized and tried in an attempt to enhance the mucoadhesive properties of MPs. All formulae were characterized for their yield, flow properties, particle size, encapsulation efficiency (EE %), morphology, and drug release and its mechanistics. Possible interactions inside MPs matrix were also elucidated using FTIR study. The suitability of the selected formulae for gastroretention was evaluated by in vitro buoyancy and ex-vivo mucoadhesion studies.All REP-loaded MPs demonstrated a passable powder flow, high yield values, promising floatation and mucoadhesion. Encapsulation efficiency % values were nearly tripled upon addition of Eudragit polymers. Compared to the Eudragit free REP loaded foam powder, all formula showed more sustained release features. Eudragit L100-SH was synthesized and confirmed by FTIR. Furthermore, its incorporation, alone or in combination, exhibited a significant increase in mucoadhesion strength compared to the unmodified one.Dual buoyant/mucoadhesive MPs loaded with REP encourage planning for future in-vivo performance studies for the management of diabetes

Precise Cerebrovascular Segmentation

© 2020 IEEE. Analyzing cerebrovascular changes using Time-of-Flight Magnetic Resonance Angiography (ToF-MRA) images can detect the presence of serious diseases and track their progress, e.g., hypertension. Such analysis requires accurate segmentation of the vasculature from the surroundings, which motivated us to propose a fully automated cerebral vasculature segmentation approach based on extracting both prior and current appearance features that capture the appearance of macro and micro-vessels. The appearance prior is modeled with a novel translation and rotation invariant Markov-Gibbs Random Field (MGRF) of voxel intensities with pairwise interaction analytically identified from a set of training data sets, while the current appearance is represented with a marginal probability distribution of voxel intensities by using a Linear Combination of Discrete Gaussians (LCDG) whose parameters are estimated by a modified Expectation-Maximization (EM) algorithm. The proposed approach was validated on 190 data sets using three metrics, which revealed high accuracy compared to existing approaches

Bayesian estimation of P[Y \u3c X] Based on Record Values from the Lomax Distribution and MCMC Technique

Our interest is in estimating the stress-strength reliability R = P[Y \u3c X], where X and Y follow the Lomax distribution with common scale parameter. We discuss the problem in the situation where the stress measurements and the strength measurements are both in terms of records. Firstly, we obtain the MLE of R in general case (the common scale parameter is unknown). The MLE of the three unknown parameters can be obtained by solving one non-linear equation. We provide a simple fixed point type algorithm to find the MLE. We propose percentile bootstrap confidence intervals of R. A Bayes point estimator of R, and the corresponding credible interval using the MCMC sampling technique have been proposed. Secondly, assuming the common scale parameter is known, the MLE of R is obtained. Using exact distributions of the MLEs of the two unknown parameters, we construct the exact confidence interval of R. In this case, Bayes estimators have been obtained using Lindley\u27s approximations. Analysis of a simulated data set has been presented for illustrative purposes. Finally, the different proposed methods have been compared via Monte Carlo simulation study

Evaluation of the safety and antioxidant activities of Crocus sativus and Propolis ethanolic extracts

AbstractThe possible toxicological effects and in vitro antioxidant activity of the ethanolic extracts of Crocus sativus and Propolis were investigated. Both extracts did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5g/kgb.wt. In the sub-chronic study; the tested extracts did not produce any significant change in liver and kidney functions of rats, following oral administration for 8 successive weeks at doses of 500mg/kgb.wt. of each. Propolis showed remarkable in vitro antioxidant activity at concentrations of (40–100mg/ml). In contrast, the ethanolic extract of C. sativus ethanolic extract showed weak antioxidant activity in concentrations of (1–10mg/ml) while at concentrations of (20–100mg/ml) failed to exhibit any antioxidant activity. It was concluded that: both extracts were non-toxic, as they did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5g/kgb.wt. Daily oral administration of C. sativus, Propolis ethanolic extracts alone or in combination for 8 successive weeks to rats was quiet safe and didn't cause any toxic changes in liver and kidney. Antioxidant study showed that Propolis ethanolic extract was a more potent antioxidant than C. sativus extract