We present a micro/nano-machining process to introduce nanostructured poly-silicon layer on the gate region of the pH-sensitive field effect transistors. Decoration of the gate of the field effect transistors by nanostructures plays an important role to improve the sensitivity of the pH-sensitive FETs. Electron beam lithography was exploited to realize the poly-Si nanopillars on the gate surface. Comparison between different micro and nanostructures demonstrates the potential of nanopillars to be utilized on the gate of this device rather than micro-conical structures (different size and shapes) and vertically carbon nanotubes. A high sensitivity of 500 mV/pH has been achieved, through the incorporation of silicon based nanopillars.

Facilities built in areas affected by earthquake activity, such as tunnels, which have always been an integral part of human life, must withstand both dynamic and static loading. It has led to the need for practical studies on the effects of earthquakes on underground structures and the factors affecting their destruction. For this purpose, in this research, at first different patterns of tunnel’s excavation were investigated and by using Plaxis 2D software and based on Tabas earthquake in Iran, sensitivity analysis on geotechnical parameters of the soil surrounding tunnel such as cohesion, friction angle, unit weight and modulus of elasticity was carried out, and the parameters whose changes have the greatest and least effects on the bending moment changes on the tunnel lining are introduced. The results show that tunnel excavation patterns significantly affect the bending moment, axial forces, displacements, and surface settlement of the tunnel. Often, by dividing tunnel excavation area to small parts, the values of bending moment, axial forces, displacements, and surface settlement of the tunnel decreases in static analysis. Also, outputs of sensitivity analysis on geotechnical parameters of the soil surrounding tunnel showed that modulus of elasticity of the soil surrounding tunnel has the most effect and cohesion changes have the least effect on bending moment induced on tunnel lining..

Objective(s): In this study, a kind of pH sensitive composite membrane was prepared and drug permeation through it was investigated in terms of pH. Rationale of this study originated from the fact that a pH change which may be a result of a disease state in the body can trigger drug release.Materials and Methods: Here, a kind of pH sensitive composite membrane containing different nanoparticle [1: 1 n-isopropyl acrylamide (Nipam): metacrylic acid (Maa)] contents in ethylcellulose was prepared by a casting method.Swelling ratios of these nanoparticles and composite membranes with different particle loadings were determined. Permeation of two different drug models with different hydrophilicity and molecular weights, vitamin B12 (vit B12) and paracetamol, through these membranes was studied in terms of pH. Results: It was seen that swelling ratios of nanoparticles and the composite membranes went up as the particle content increased at each pH. Vit B12 and paracetamol permeation through the membranes in pH value below the pKa was much higher than that at pHs above it, but this difference was much more pronounced for vit B12 compared to paracetamol.Conclusion: Permeation through these membranes showed a sharp sensitivity to pH changes. Nanoparticles in the composite membranes could act as nanovalves due to their sharp swelling/shrinkage around the pKa of Maa. These membranes could be considered as an ideal stimuli-sensitive barrier for modulating drug release with a small change in pH.

The development of an optical pH sensor based on immobilization of quinizarin (1,4-dihydroxyanthraquinone) on a triacetylcellulose membrane was described. The resulting membrane exhibited fast color change from yellow to violet, while changing the pH in alkaline region. The immobilized quinizarin showed a broader dynamic range from (pH 9.4-11.4) with respect to free form (pH 8.8-10.4). The sensor response was fully reversible and fast (<20 s) under the batch conditions with pH between 7 and 12.5. The sensor showed excellent long term stability (more than three months) and high reproducibility (R.S.D. less than 2%). The Ka values for free and immobilized dye were evaluated and the chemical reactivity of the quinizarin in solution and after immobilization was also described.

The pH-sensitive hydrogels were synthesized via in situ copolymerization of methacrylic acid (MAA) with poly (ethylene glycol) -b-poly ( e-caprolactone) (PEGb- PCL) macromer as a biodegradable cross-linker in aqueous solutions under UV irradiation. The swelling measurement results indicated that pH sensitivity of the hydrogels was highly dependent on the MAA content in the hydrogels as well as the pH of the surrounding medium. The pH-sensitive hydrogels displayed faster deswelling rates and lower water retentions at high MAA content. In vitro hydrolytic degradation investigation showed that the introduction of MAA component could improve the degradation rate of the hydrogels, and an increase in its content could induce accelerated degradation of the hydrogel at pH 7.4 of PBS solutions at 37°C. The potential of the hydrogels as vehicles for delivering BSA was examined. The accumulative release percentage of BSA (Fraction V) as a model protein drug could be tuned by changing the compositions of the hydrogels and pH of the local medium. The release mechanism of BSA based on the Peppas equation followed the non-Fickian diffusion at pH 7.4 of PBS solutions at 37oC. The interior morphology of the hydrogels was also observed by scanning electron microscopy (SEM) after freeze drying at their equilibrium states of pH 7.4 of PBS solutions. The results revealed that the pore size of the hydrogels became larger when introducing the MAA moieties and increased with the increase of the MAA content of the hydrogels. These biodegradable pH-sensitive synthetic hydrogels could be potentially used as smart drug delivery systems.

Background: C-reactive protein (CRP) is a predictor of cardiovascular diseases in both normal people and patients on hemodialysis. This study aimed to assess the relationship of high-sensitivity C-reactive protein (Hs-CRP) serum level and peritonitis in patients on peritoneal dialysis.Methods: 113 patients on peritoneal dialysis in Isfahan city, Iran, participated in our study in 2015. Serum albumin and Hs-CRP levels were measured in each patient at three times (baseline, and 6 and 12 month after that) and the patients were followed up for 1 year. All the patients were evaluated for peritonitis in every visit. At the end of the study, two groups of patients on peritoneal dialysis with and without peritonitis were compared. Findings: Among 113 patients, 24 were excluded from the study because of death or kidney transplantation and 89 patients were included in final analysis. The mean Hs-CRP levels in patients with peritonitis were 4.83, 5.79, and 7.42 mg/l at baseline, and 6 and 12 month after it, respectively; these levels were 4.47, 3.19, and 2.69 mg/l in patients without peritonitis, respectively. In addition, the mean albumin levels in patient with peritonitis were 3.38, 3.29 and 3.40 mg/l at baseline, and 6 and 12 month after it, respectively; these values were 3.56, 4.05, and 3.51 mg/l in patients without peritonitis, respectively.Conclusion: Results showed that with increase in Hs-CRP level, the risk of peritonitis increased. Besides, the albumin level decreased among patients with peritonitis in comparison with patients without peritonitis; there was no significant correlation between albumin level and peritonitis.

Introduction: Because of improvements in the measurement methods of FSH levels in serum, there is less interest in evaluating vaginal pH for the diagnosis of menopause nowadays. The traditional test to diagnose menopause has been FSH, so far. In recent studies it has been shown that diagnosis of menopause by testing for vaginal pH is a simple, non-invasive and inexpensive method .This study intended to compare diagnostic value of vaginal pH and serum FSH in the diagnosis of menopause. Materials & Methods: This article is a descriptive cross-sectional study taking place from June to July 2005. 120 menopausal women, aged 31 to 95 years that were being referred to a menopausal clinic in Qaem Hospital during the study, were chosen by a target-based nonrandom sampling technique for the study. A questionnaire was used for collecting data from the patients. In addition, pH test strips were used for vaginal pH measurements and the patients' serum FSH were evaluated in a definite laboratory and their clinical signs and symptoms were recorded. The data was analyzed by SPSS software and the statistical significant of the results were tested by χ2 in comparison with the kappa coefficient of agreement. P≤0.05 was considered as the significance level of the study.Results: According to the gathered data in the study, the average vaginal pH in the patients, in the absence of vaginal infections, was 5.33±0.53 (with a minimum of 4.1 and a maximum of 5) With attention to the cut of point of 4.5 for vaginal pH and the baseline FSH>20 mIU/ml that characterizes menopause, the sensitivity of pH-meter in diagnosing menopause was determined to be 97%. The mean average and the standard deviation of FSH levels in this study was 80.79 ±6.42. Conclusion: Vaginal pH sensitivity in the diagnosis of menopause is similar to serum FSH and could be used as a suitable alternative.