pH in the vertebrate retina and its naturally occurring and pathological changes.

This review summarizes the existing information on the concentration of H (pH) in vertebrate retinae and its changes due to various reasons. Special features of H homeostasis that make it different from other ions will be discussed, particularly metabolic production of H and buffering. The transretinal distribution of extracellular H concentration ([H]) and its changes under illumination and other conditions will be described in detail, since [H] is more intensively investigated than intracellular pH.

A Study of the Possibility of Producing Annealed and Metallized Pellets from Titanomagnetite Concentrate.

The current intensive development of steelmaking is being impeded by a scarcity of pure scrap. The potential to replace pure scrap with metallized raw materials that are naturally alloyed with vanadium and titanium, such as annealed unfluxed titanomagnetite pellets, could facilitate the achievement of key objectives in metallurgical development, particularly in the smelting of electric steel. The objective of this research was to produce annealed and metallized pellets from titanomagnetite concentrate under laboratory conditions, with the intention of further processing them as a commercial product in a blast furnace or as an intermediate product for the production of hot briquetted iron (HBI).

Increased Retinal Metabolism Induced by Flicker in the Isolated Mouse Retina.

Both the retina and brain exhibit neurovascular coupling, increased blood flow during increased neural activity. In the retina increased blood flow can be evoked by flickering light, but the magnitude of the metabolic change that underlies this is not known. Local changes in oxygen consumption (QO) are difficult to measure in vivo when both supply and demand are changing.

Elemental composition and metal pollution in Egyptian Red Sea mangrove sediments: Characterization and origin.

The present work was conducted to characterize the mangrove sediments along the Egyptian Red Sea in terms of elemental composition and to assess the extent of pollution and its sources. A total of 26 samples of mangrove sediments were collected from three different areas: Sharm El Madfea, Sowmaa Mangrove and Abu Fasi. The samples were analyzed using the inductively coupled plasma - mass spectrometry ICP-MS and atomic-emission spectrometry ICP-AES.

Elemental distribution patterns in rock samples from Egypt using neutron activation and complementary X-ray fluorescence analyses.

The study utilized instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF) to accurately analyze the elemental composition of 28 felsite (rhyolite), rock samples. Statistical approaches, including bivariate and multivariate analysis, were employed to characterize the rocks and determine their origin. Major findings include significantly high levels of silicon (297000 ± 4000) mg/kg and low levels were noticed for gold (0.

Diabetes-Induced Changes of the Rat ERG in Relation to Hyperglycemia and Acidosis.

Purpose: To understand the mechanism of changes in the c-wave of the electroretinogram (ERG) in diabetic rats, and to explore how glucose manipulations affect the c-wave.

Methods: Vitreal ERGs were recorded in control and diabetic Long-Evans rats, 3-60 weeks after IP vehicle or streptozotocin. A few experiments were performed on Brown Norway rats.

Oxygen profiles and oxygen consumption in the isolated mouse retina.

The retina has a large demand for oxygen, but there is only limited information on differences between oxygen utilization (QO) in the inner and outer retina, and limited data on mouse, which has become a prevalent animal model. This study utilized the isolated mouse retina, which allowed more detailed spatial analysis of QO than other methods. Oxygen sensitive microelectrodes were used to obtain profiles of oxygen tension across the isolated mouse retina, and mathematical models of retinal oxygen diffusion with four and five layers were fitted to the data to obtain values for QO of the outer retina (QOR) and inner retina (QIR).

Anatomical variability of kidney arterial vasculature based on zonal and segmental topography.

Introduction: To date, there is no unified approach to the lobar, zonal, and segmental structure of the kidney vasculature. There is no recognizable approach to define basic characteristics in regard to the lobes and segments identifying of the kidney. The branching of the renal artery has often been the subject of scientific research.

Geochemical ceramic composition dataset using neutron activation and statistical analyses.

These are comprehensive baseline data on the geochemical composition of archeological ceramics analyzed using instrumental neutron activation analysis (INAA). The data obtained support the research article conducted to evaluate the elemental composition of 70 sherds that were collected from different locations [1], [2], [3]. The mass fractions in wt% and in mg/kg of 39 oxides and elements were determined, respectively.

Contribution of Tin to the Strain Hardening of Self-Lubricating Sintered Al-30Sn Alloy and Its Wear Resistance under Dry Friction.

Aluminum alloys, which have been widely used in various manufacturing industries as an upper layer of bearing inserts, are alloyed with Sn to decrease the intensity of adhesive wear. A relationship between the mechanical properties, wear resistance, and structure of sintered Al-30Sn alloy containing a large amount of the soft phase was studied in this work. The above-mentioned characteristics were determined by testing the investigated material under compression and wear under dry friction in the pin-on-disk geometry at a sliding speed of 0.

Extracellular K reflects light-evoked changes in retinal energy metabolism.

Retinal neurons spend most of their energy to support the transmembrane movement of ions. Light-induced electrical activity is associated with a redistribution of ions, which affects the energy demand and results in a change in metabolism. Light-induced metabolic changes are expected to be different in distal and proximal retina due to differences in the light responses of different retinal cells.

Datasets of trace elements in shallow marine sediments along the Egyptian shore of the Mediterranean and Red Seas.

A comprehensive dataset concerning the geochemical composition of unconsolidated shallow marine sediments collected along coastal areas of Northern Nile Delta and Egyptian sector of Red Seas is presented. The sediment samples were analyzed using instrumental neutron activation analysis (INAA) in Frank Laboratory of Neutron Physics FLNP - Joint Institute for Nuclear Research JINR and inductively coupled plasma - mass spectrometer (ICP-MS) in Actlabs - Canada. Data thus collected supported the research published and published articles conducted to evaluate the geochemistry of shallow marine sediments covering mentioned areas [1], [2], [3].

Characterization of major and trace elements in coastal sediments along the Egyptian Mediterranean Sea.

The present study was conducted to provide a comprehensive picture of marine sediment characterization in terms of geochemistry and the extent of pollution. A total of 99 surface coastal sediments were collected from coastal areas along with the Egyptian Mediterranean Sea. The samples were analyzed by neutron activation analysis (NAA) and the mass fractions in mg/kg of 39 trace elements were determined.

Tribotechnical Properties of Sintered Antifriction Aluminum-Based Composite under Dry Friction against Steel.

The disadvantage of antifriction Al-Sn alloys with high tin content is their low bearing capacity. To improve this property, the aluminum matrix of the alloys was alloyed with zinc. The powder of Al-10Zn alloy was blended with the powder of pure tin in the proportion of 40/60 (wt.

Analysis of the Quasi-Static and Dynamic Fracture of the Silica Refractory Using the Mesoscale Discrete Element Modelling.

Computer modelling is a key tool in the optimisation and development of ceramic refractories utilised as insulation in high-temperature industrial furnaces and reactors. The paper is devoted to the mesoscale computer modelling of silica refractories using the method of homogeneously deformable discrete elements. Approaches to determine the local mechanical properties of the constituents from the global experimental failure parameters and respective crack trajectories are considered.

Characteristic Features of Ultrafine-Grained Ti-45 wt.% Nb Alloy under High Cycle Fatigue.

The paper presents the results of fatigue-testing ultrafine-grained and coarse-grained Ti-45 wt.% Nb alloy samples under very high cycle fatigue (gigacycle regime), with the stress ratio R = -1. The ultrafine-grained (UFG) structure in the investigated alloy was formed by the two-stage SPD method, which included multidirectional forging (abc-forging) and multipass rolling in grooved rollers, with further recrystallization annealing.

K-dependent Müller cell-generated components of the electroretinogram.

The electroretinogram (ERG) has been employed for years to collect information about retinal function and pathology. The usefulness of this noninvasive test depends on our understanding of the cell sources that generate the ERG. Important contributors to the ERG are glial Müller cells (MCs), which are capable of generating substantial transretinal potentials in response to light-induced changes in extracellular K+ concentration ([K+]o).

Advances in Laser Additive Manufacturing of Ti-Nb Alloys: From Nanostructured Powders to Bulk Objects.

The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm.

Intravenous ketamine for long term anesthesia in rats.

Ketamine/xylazine anesthesia has been used primarily for short term procedures in animals, but two prior reports used intravenous ketamine/xylazine for experiments taking many hours. However, there is a discrepancy about the appropriate dose, which is resolved here. Adult Long-Evans rats were used for recording from the retina.

Suppression of wear in dry sliding friction induced by negative thermal expansion.

Surface temperature is among crucial factors which control wear during sliding dry contact. Using computer modeling, we study the possibility to achieve close to zero rate of surface wear during sliding friction of the special type of materials which possess negative thermal expansion. The numerical simulations reveal two wear regimes for materials with negative thermal expansion coefficient as dependent on the applied normal stress level.

Effect of elastic grading on fretting wear.

We consider fretting wear in elastic frictional contact under influence of oscillations of small amplitude and investigate the question, how wear damage can be influenced by the introduction of material gradients. To achieve a general understanding we restrict our consideration to media with a power-law dependency of the elastic modulus on depth. In this case, a complete analytical solution can be found for the final worn shape.

Diabetes Alters pH Control in Rat Retina.

Purpose: The purpose of this study was to determine whether the ability of the rat retina to control its pH is affected by diabetes.

Methods: Double-barreled H+-selective microelectrodes were used to measure extracellular [H+] in the dark-adapted retina of intact control and diabetic Long-Evans rats 1 to 6 months after intraperitoneal injection of vehicle or streptozotocin, respectively. Two manipulations-increasing of blood glucose and intravenous injection of the carbonic anhydrase blocker dorzolamide (DZM)-were used to examine their effects on retinal pH regulation.

Retinal pH and Acid Regulation During Metabolic Acidosis.

Purpose: Changes in retinal pH may contribute to a variety of eye diseases. To study the effect of acidosis alone, we induced systemic metabolic acidosis and hypothesized that the retina would respond with altered expression of genes involved in acid/base regulation.

Methods: Systemic metabolic acidosis was induced in Long-Evans rats for up to 2 weeks by adding NHCl to the drinking water.

Brain tissue oxygen regulation in awake and anesthetized neonates.

Inhaled general anesthetics are used commonly in adults and children, and a growing body of literature from animals and humans suggests that exposure to anesthesia at an early age can impact brain development. While the origin of these effects is not well understood, it is known that anesthesia can disrupt oxygen regulation in the brain, which is critically important for maintaining healthy brain function. Here we investigated how anesthesia affected brain tissue oxygen regulation in neonatal rabbits by comparing brain tissue oxygen and single unit activity in the awake and anesthetized states.