Effect of Static Magnetic Field on Bone Marrow Cellular Density

This study was undertaken to investigate the influence of static magnetic field (SMF) on bone marrow cellular density (BMCD) variation proportionally to bone trabeculae. Female albino Wistar rats exposed with 2.4 ± 0.2 millitesla for 1–4weeks duration continuously versus 1h, 2h, 6h, and 8h/day. Trephine biopsy of femurs bone was examined under optical microscope. Data analyzed with ImageJ software. Results showed that short time exposure per day did not enhance the BMCD compare to high exposure period/day. Six hours/day exposure during 1week increased the marrow cellular density (hypercellularity) significantly (P ≤ 0.05) compares to bone trabeculae. Contrarily, 8h/day exposure reduced the BMCD slightly and significantly (hypocellularity, about 50% reduction) due to 1week and 4weeks exposure duration, respectively. The SMF has associated bone marrow cellularity tendency of rat’s femur

Moderate Range Static Magnetic Field Promoted Variation of Blood Parameters: An In vitro Study

This study was undertaken to investigate the influence of a homogenous and uniform static magnetic field (SMF) on the main blood cell counts in vitro experiment. Fresh blood samples were collected from albino rats and exposed to SMF (2.4, 6, 25, 50, 75, and 100 mT) versus 15–60 min. Results showed a significant change of blood counts under the low field effects. A 2.4 mT was a trend of white blood cells (WBCs) count increase non-linearly. However, a 6 mT exposure reduced WBCs with about 39%. Other variations fluctuated within 30%. The 25 mT decreased red blood cells (RBCs), hemoglobin, and hematocrit levels with 13% similarly. The lower exposure field, (2.4 and 6) mT, and effects on RBCs were 6% fluctuation. The 6 mT reduced platelet counts with half in comparison to control blood samples. About 20% increase obtained due to 50 mT exposure during all period. None of 75 and 100 mT exposures dominated blood counts alterations. The quiet magnetic field exposure for a certain time can be interesting to control blood cell count-related diseases

Infrared and upconversion spectroscopic studies of high Er3+content transparent YAG ceramic

In this article, we report the detailed spectroscopic studies of high Er3+content (50%) transparent YAG ceramic co-doped with nominal Cr3+ content (0.1 mol %). Various radiative and non-radiative spectroscopic properties such as radiative decay time, fluorescence branching ratio, emission/absorption cross sections, internal radiative quantum yields of the infrared and the upconverted emission bands are explored using standard experimental and theoretical methods and compared with YAG single crystal. Results show that although the non-radiative losses are high for 50% Er doped ceramic; several radiative spectral properties are almost in agreement with those for the single crystal YAG. Furthermore, because of the low dopant concentration of Cr3+, the sensitizing effect of Cr3+ was not observed. © 2011 Optical Society of America

Chronic Hypobaric Hypoxia Modulates Primary Cilia Differently in Adult and Fetal Ovine Kidneys

Hypoxic environments at high altitude have significant effects on kidney injury. Following injury, renal primary cilia display length alterations. Primary cilia are mechanosensory organelles that regulate tubular architecture. The effect of hypoxia on cilia length is still controversial in cultured cells, and no corresponding in vivo study exists. Using fetal and adult sheep, we here study the effect of chronic hypobaric hypoxia on the renal injury, intracellular calcium signaling and the relationship between cilia length and cilia function. Our results show that although long-term hypoxia induces renal fibrosis in both fetal and adult kidneys, fetal kidneys are more susceptible to hypoxia-induced renal injury. Unlike hypoxic adult kidneys, hypoxic fetal kidneys are characterized by interstitial edema, tubular disparition and atrophy. We also noted that there is an increase in the cilia length as well as an increase in the cilia function in the hypoxic fetal proximal and distal collecting epithelia. Hypoxia, however, has no significant effect on primary cilia in the adult kidneys. Increased cilia length is also associated with greater flow-induced intracellular calcium signaling in renal epithelial cells from hypoxic fetuses. Our studies suggest that while hypoxia causes renal fibrosis in both adult and fetal kidneys, hypoxia-induced alteration in cilia length and function are specific to more severe renal injuries in fetal hypoxic kidneys

Congestive Heart Failure Leads to Prolongation of the PR Interval and Atrioventricular Junction Enlargement and Ion Channel Remodelling in the Rabbit.

Heart failure is a major killer worldwide. Atrioventricular conduction block is common in heart failure; it is associated with worse outcomes and can lead to syncope and bradycardic death. We examine the effect of heart failure on anatomical and ion channel remodelling in the rabbit atrioventricular junction (AVJ). Heart failure was induced in New Zealand rabbits by disruption of the aortic valve and banding of the abdominal aorta resulting in volume and pressure overload. Laser micro-dissection and real-time polymerase chain reaction (RT-PCR) were employed to investigate the effects of heart failure on ion channel remodelling in four regions of the rabbit AVJ and in septal tissues. Investigation of the AVJ anatomy was performed using micro-computed tomography (micro-CT). Heart failure animals developed first degree heart block. Heart failure caused ventricular myocardial volume increase with a 35% elongation of the AVJ. There was downregulation of HCN1 and Cx43 mRNA transcripts across all regions and downregulation of Cav1.3 in the transitional tissue. Cx40 mRNA was significantly downregulated in the atrial septum and AVJ tissues but not in the ventricular septum. mRNA abundance for ANP, CLCN2 and Navβ1 was increased with heart failure; Nav1.1 was increased in the inferior nodal extension/compact node area. Heart failure in the rabbit leads to prolongation of the PR interval and this is accompanied by downregulation of HCN1, Cav1.3, Cx40 and Cx43 mRNAs and anatomical enlargement of the entire heart and AVJ

All-Polymer Microcavities for the Fluorescence Radiative Rate 2 Modification of a Diketopyrrolopyrrole Derivative

Controlling the radiative rate of emitters with 6 macromolecular photonic structures promises flexible devices with 7 enhanced performances that are easy to scale up. For instance, radiative rate enhancement empowers low-threshold lasers, while rate suppression affects recombination in photovoltaic and photochemical processes. However, claims of the Purcell effect with polymer structures are controversial, as the low dielectric contrast typical of suitable polymers is commonly not enough to provide the necessary confinement. Here we show all-polymer planar microcavities with photonic band gaps tuned to the photoluminescence of a diketopyrrolopyrrole derivative, which allows a change in the fluorescence lifetime. Radiative and nonradiative rates were disentangled systematically by measuring the external quantum efficiencies and comparing the planar microcavities with a series of references designed to exclude any extrinsic effects. For the first time, this analysis shows unambiguously the dye radiative emission rate variations obtained with macromolecular dielectric mirrors. When different0 waveguides, chemical environments, and effective refractive index effects in the structure were accounted for, the change in the radiative lifetime was assigned to the Purcell effect. This was possible through the exploitation of photonic structures made of polyvinylcarbazole as a high-index material and the perfluorinated Aquivion as a low-index one, which produced the largest dielectric contrast ever obtained in planar polymer cavities. This characteristic induces the high confinement of the radiation electric field within the cavity layer, causing a record intensity enhancement and the steering the radiative rate. Current limits and requirements to achieve the full control of radiative rates with polymer planar microcavities are also addressed