Association between testicular Aryl hydrocarbon Receptor levels and idiopathic male infertility: a case-control study in Iran

Increased urinary concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and their metabolites are associated with increased risk of unexplained infertility in males. The toxicity of PAHs and dioxins are exclusively mediated through Aryl hydrocarbon Receptor (AhR). AhR overexpression contributes to the loss of normal ovarian function in polluted environments but its expression level in unexplained male infertility has remained unclear. This study aimed to compare the differential testicular levels of AhR and its interactions with other fundamental genes (ER, AR, PgR and MMP9) in a case control study. To conduct the immunohistochemical studies, 29 unexplained infertile and 10 fertile males were selected retrospectively from Jahad pathology center of Tehran from 2007 to 2009. Differential expression of AhR in Leydig, Sertoli, spermatogonia, spermatocyte, spermatid, and spermatozoa cells was determined and AhR association with other genes was compared between cases and controls. Higher levels of AhR in Leydig cells (p = 0.024), Sertoli cells (p = 0.041) and spermatid cells (p = 0.028) of infertile men have emphasized the susceptibility of these cells to environmental-induced impaired testicular functions. Moreover 85% of infertile cases showed coexpression of AhR and MMP9 in their Leydig cells (p = 0.02). Inactivation of ER, PgR and AR in AhR positive testicular cells suggests the antagonistic interactions between AhR ligands and sex steroid hormones receptors. It seems that unexplained male infertility could be originated from environmental AhR ligands which overexpress the AhR in Leydig cells, downregulate the expression of sex steroid receptors and upregulate the MMP9 in Leydig cells as the main testicular target cell of AhR ligands.     

Groundwater Source Identification and Flow Model of the Dareh-Zar Copper Mine in Central Iran by Chemo-isotopic Techniques

Mine Water and the Environment - Seepage with AMD characteristics is observed in the Dareh-Zar copper mine in central Iran and more water inrush events are expected since the pit extends below the...     

A New Cascaded Multi-level Inverter Topology with Reduced Number of Components and Charge Balance Control Methods Capabilities

In this article, a new basic unit for cascaded multi-level inverter is proposed. This inverter is able to increase the number of output voltage levels and reduces the number of power electronic devices. To generate all voltage levels at the output, five different algorithms to determine the magnitude of DC voltage sources are suggested. This inverter is compared with conventional cascaded multi-level inverters. The comparisons show that the proposed topology needs fewer DC voltage sources and power switches, less variety of the magnitude of DC voltage sources, and smaller amounts of blocked voltage by switches. As a result, the installation space and total cost of the inverter decrease. As it is impossible to use charge balance control methods for the asymmetric cascaded multi-level inverters, the developed topology based on the proposed cascaded inverter–the sub-symmetric topology with the usability of charge balance control methods–is proposed. A new algorithm is proposed to determine the magnitude of DC voltage sources. In addition, full-wave and half-wave charge balance control methods are applied in the proposed developed topology. The accurate performance of the proposed topology by applying charge balance control methods is verified through the simulation and experimental results of an 81-level sub-symmetric inverter.     

Effects of Ultrasound Amplitude on the Physicochemical Properties of Some Edible Oils

This research reports on the studied effect of the intensity of ultrasound (24 kHz) on the quality characteristics of olive oil, sesame oil, sunflower seed oil, and tallow olein. These characteristics (free acidity, peroxide value, conjugated dienes concentration, viscosity, iodine value, turbidity, color values, and melting behavior) were determined in oil samples before and after ultrasonic treatment. Changes in the oxidation parameters showed that the high‐intensity ultrasound treatment accelerated the deterioration of oils. In most cases, extra‐virgin sesame oil was most resistant to deterioration from sonicating treatments. The decreases in β‐carotene content and Hunter values revealed that ultrasound might have good potential for bleaching oils at an appropriate intensity and frequency. The differential scanning calorimeter thermograms, viscosity, and turbidity results indicated that ultrasound probably accelerates the polymerization of the oils. The present study has confirmed that some changes in the physicochemical parameters or structures of oil components had occurred. These changes depended on the sources and initial conditions of the oils as well as the intensity of the applied ultrasound.     

Multi-pinhole SPECT Imaging with Silicon Strip Detectors

Silicon double-sided strip detectors offer outstanding instrinsic spatial resolution with reasonable detection efficiency for iodine-125 emissions. This spatial resolution allows for multiple-pinhole imaging at low magnification, minimizing the problem of multiplexing. We have conducted imaging studies using a prototype system that utilizes a detector of 300-micrometer thickness and 50-micrometer strip pitch together with a 23-pinhole collimator. These studies include an investigation of the synthetic-collimator imaging approach, which combines multiple-pinhole projections acquired at multiple magnifications to obtain tomographic reconstructions from limited-angle data using the ML-EM algorithm. Sub-millimeter spatial resolution was obtained, demonstrating the basic validity of this approach.