The Effect of Gold Nanoparticle on Electrical Impedance of Tissue on Low Frequency Ranges

Introduction: Electrical impedance of tissues on low frequencies includes useful information about functional and structural changes in tissues. This property is used in Electrical Impedance Tomography (EIT) imaging modality for the detection of lesions in tissues. Objective: The goal of this article is to study changes in electrical impedance of tissues in the presence of gold nanoparticles. Materials and Methods: Spherical gold nanoparticles with size of 20-25 nm were synthesized with Turkevich method. Size distribution and shape of nanoparticles were characterized by transmission electron microscopy (TEM). Electrical impedance of two types of phantoms (chicken fat and muscle paste tissues) was measured by 4-electrode method with and without gold nanoparticles. Results: Results demonstrate a reduction in electrical impedance of tissues in the presence of gold nanoparticles. However, this reduction is not the same for fat and muscle tissues. Reductions in resistive impedance are for fat and muscle tissues on the frequency of 1 KHz, respectively. A reduction in electrical impedance is accompanied by a rise in electrical conductance leading to increase in EIT signal. Conclusion: As signal enhancement is different for fat and muscle tissues; presence of gold nanoparticles could be used to improve EIT image contrast

Designing and testing a network of passive seismic surveying and monitoring in Dehdasht (South Western Iran)

From August 2016 to July 2017, a passive seismic survey was conducted in South Western Iran as a part of a pilot project aimed to improve the imaging in geologically complex areas. Passive seismic methods have shown to be a useful tool to infer the physical properties of the underground geological structures where traditional hydrocarbon exploration methods are challenging. For this purpose, a dense passive seismic network consisting of 119 three-component borehole seismic stations was deployed over an area of 400 km 2 around the city of Dehdasht. This paper focuses on the details of the network design, which was devoted to high-resolution seismological applications, including local earthquake tomography and seismic attenuation imaging. In this regard, we describe the instrument types and the station installation procedures used to obtain high-quality data that were used to retrieve three-dimensional models of P- and S-wave velocity and P-wave attenuation in the area using tomographic inversion techniques. We also assess the network performance in terms of the seismic ambient noise levels recorded at each station site, and we revise the horizontal orientation of the sensors using surface waves from teleseismic earthquakes. © 2019 European Association of Geoscientists & EngineersThis work would not have been possible without the support of the Exploration Directorate of the National Iranian Oil Company.Peer reviewe

Skeletal muscle hypertrophy, insulin-like growth factor 1, myostatin and follistatin in healthy and sarcopenic elderly men:the effect of whole-body resistance training

Background: Sarcopenia describes the inevitable deterioration in muscle mass and strength that accompanies biological aging. The purpose of this study was to investigate the effects of resistance training (RT) on quadriceps hypertrophy and related biochemistry in sarcopenic and healthy elderly men. Methods : A total of 31 elderly men (55–70 years old) were classified as sarcopenic and nonsarcopenic and were divided into two groups. Both groups participated in a progressive RT program for 8 weeks. Results: Data indicated that the strength in the sarcopenic group increased more than the healthy group ( P < 0.05). Quadriceps cross‑sectional area also increased more in the healthy group ( P < 0.05). Myostatin concentration decreased in both groups after training ( P < 0.05). Follistatin and testosterone increased in the healthy group; in contrast, only testosterone increased in the sarcopenic group after training ( P < 0.05). Conclusions: The findings from this study suggest that RT improves muscle cross‑sectional area and biomarker‑related muscle loss in both healthy and sarcopenic elderly men. The findings also demonstrate that growth factor profiles at baseline and changes in testosterone levels play an important role in muscle hypertrophy observed in both groups