Mustafa Erdem Sağsöz

Proton channels play an important role in many physiological processes in humans, as in all organisms, since pH determines protonation or deprotonisation state of amino acid residues, thus channel activity, enzyme kinetics, receptor-ligand interactions by changing the surface charges of molecules. These integral protein structures, which selectively transport protons through biological membranes, are very important for cell homeostasis, energy production and signal transmission. Human diseases linked to proton channels can be effectively studied using genetic model organisms, as the fundamental structure and function of these channels are conserved across species. Proton channels in humans, are an important part of many vital processes, including the regulation of pH in cellular compartments, the generation of bioelectric signals in neurons, and the immune response. Studies about proton channels conducted to date, including deviations in proton channel function have been associated with a variety of diseases, from neurodegenerative disorders to cardiovascular diseases and cancer. Valuable information about their special contributions to human physiology and pathophysiology can be obtained by deciphering their different roles in these structures. The aim of this review is to provide a comprehensive overview of the biological significance of proton channels by summarizing their functions and their effects on organisms, with particular emphasis on their roles in human diseases and their potential as therapeutic targets. An integrative synthesis connecting molecular mechanisms to disease-specific pathophysiology is still lacking. This review aims to address this gap by providing a comprehensive overview of the biological significance of proton channels.

The article written by Zhao et al , which was recently accepted for publication, introduces an innovative method that combines deep learning-based feature extraction with a radiomics nomogram to create a noninvasive procedure for determining perineural invasion status in patients with rectal cancer. This method is an artificial intelligence application in which researchers segment their own datasets, derive features and analyze their weights. It was found that the support vector machine was the most effective model in the arterial and venous phases. A support vector machine is a machine learning algorithm based on a vector space that finds a decision boundary between the two classes furthest from any point in the training data.

Tissue-equivalent hydrogel dosimeters represent a class of tools that hold significant promise, particularly in the precise measurement of three-dimensional dose distributions in radiotherapy. Due to their physical properties closely resembling those of human soft tissue, these dosimeters effectively replicate the energy transfer phenomena resulting from radiation interactions, such as atomic ionization and scattering by nuclei or electrons. Consequently, tissue-equivalent dosimeters, characterized by their linear energy transfer properties, have been extensively applied in medical physics, radiation oncology, and nuclear safety. Future advancements focusing on developing more stable, less toxic, normoxic, and cost-effective dosimeters could enable their broader adoption. This review provides a comprehensive overview of the key characteristics that make hydrogel dosimeters tissue-equivalent, highlighting their benefits, limitations, and primary application areas. Additionally, it explores current advancements in polymeric gel technology and discusses future directions aimed at optimizing their performance and accessibility for broader adoption.

Proton channels play a crucial role in many biological functions, as they are responsible for the selective transport of protons across cell membranes. Recently, Otopetrins, a family of eukaryotic proton-selective ion channels, have attracted significant attention due to their diverse physiological roles. Despite the importance of Otopetrins, their structural and functional properties remain relatively unexplored. As a model organism, crayfish have been extensively studied to gain insights into the functioning of the nervous system. These studies cover a wide range of aspects, including the properties of individual neurons and behavioral science. However, studying the physiological systems of crayfish poses challenges for molecular research due to limited molecular sequence information available for these organisms. In the present work was identified an originally cloned mRNA, coding an Otopetrin like proton channel in the crayfish. The coded protein was modeled in silico and possible conduction mechanisms and pathways were revealed. A plasmid of the cloned mRNA was heterologously expressed in HEK293T cells. Functional experiments on transfected cells indicated that the expressed mRNA was coupled to proton conduction across the cell membrane.

Adjusting the dose of radiation which is received by a cancer patient during radiotherapy is very important. The use of dosimetric gels to calculate the applied dose distribution three- dimensionally is a current research topic in radiotherapy. In this study, 16 different Fricke gels including gluconic acid (GA) were produced. These gels were irradiated from 0 to 250 cGy with increments of 50 cGy. MR intensity values and images, UV absorbance values and FT-IR spectra of gels were obtained before and after the irradiation process. The UV absorbance and MR intensity values showed a linear increase in relation to the increase in the applied dose and the amount of ferrous sulfate and GA content in the gels. The oxidation of iron increases as a result of the interaction with hydrogen peroxide which is the product of the irradiation process and GA, and thus the response of the gel to the irradiation process becomes more effective.

Gel dosimeters are unique materials capable of showing three dimensional (3D) dose distributions of therapeutic or diagnostic exposures. Fricke gel dosimeters can be considered as chemical dosimeters that rely on a radiation-induced chemical reaction. Dose distribution of Fricke solutions containing Fe⁺² ions determines the transformation of acidic, oxygen saturated Fe⁺² ions to Fe⁺³ ions by the ionizing radiation in aqueous solutions. In this study we produced two different types of gel dosimeters using agar and bovine gelatin with similar fabrication methods. We compared the magnetic resonance (MR) T1 imaging responses of these two gel dosimeters to acquire a dose dependency of MR intensities. In conclusion agar gel dosimeters found to be produced easily and more consistent.

In a computed tomography (CT) examination, scanogram images are used to determine the range of the area to be imaged before scanning. The importance of scanogram image exposure has increased since total examination radiation has decreased due to technological advancements. The purpose of this study was to determine and compare radiation doses delivered to patients while the tube was in anterior-posterior (AP) and posterior-anterior (PA) positions during a CT angiography scanogram. The radiation doses absorbed by the breast tissue of 55 female patients who underwent cardiac dual-source computed tomography (DSCT) angiography were determined using thermoluminescent dosimeters (TLD-100, Harshaw, MA, USA). Four patients were excluded from the study for various reasons. Radiation doses absorbed by the breasts were significantly lower when the tube position was switched during the scanogram. The absorbed doses, calculated from scanogram exposures, were 520 ± 50 μSv for the AP projection and 410 ± 45 μSv for the PA projection. Total skin doses from the DSCT examinations were 18.9 ± 2.3 mSv. We attributed the approximately 20% lower doses to the position of the scanogram tube, which was in the PA position.

Interrupted aortic arch is a rare congenital malformation of the aortic arch defined as a loss of luminal continuity between the ascending and descending portions of the aorta. In a simple interrupted aortic arch, only a ventricular septal defect and patent ductus arteriosus are observed. We present a rare complex form of type A interrupted aorta with an aortopulmonary window, an atrial septal defect, a ventricular septal defect, and a patent ductus arteriosus on multidetector computed tomography (MDCT) imaging.

The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Perfusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.