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Bioengineering Aids to Reproductive Medicine
Published in Sujoy K. Guba, Bioengineering in Reproductive Medicine, 2020
Interactions are at all levels of organization of the body. Cellular level interactions are particularly important. The cell membrane has been suggested as a likely site for the radiations to act. Many investigators have looked in to the transport across the erythrocyte membrane. Ion transfer rates are affected. Exposure to 2.45-GHz continuous wave microwave at 6 W/kg (approximate field strength 87 V/m) produces inhibition of sodium/potassium ATPase activity at 25 C. It is hypothesized that the structural elements of the enzyme undergo modification. In vitro studies have also shown effects on other cell functions. Cell type specific inhibitory effects on proliferation of cultured cells exposed to 2.45-GHz microwaves has been seen. The growth of synchronized L60T cells was altered by microwave exposure only during the mitotic (M) and intermitotic (Gl) phases of the cell cycle. Whether these actions have significance relating to the response of gametes of reproduction exposed to microwaves is not clear. But a more chronic irradiation of male germ cells of the mouse does in some cases produce chromosomal aberrations although results from different studies are quite variable.64,65 Comparable well controlled studies for the ovum are not reported.
Luminescent Lanthanide Probes as Diagnostic and Therapeutic Tools
Published in Astrid Sigel, Helmut Sigel, Metal Ions in Biological Systems, 2004
With respect to the triplet-to-metal ion transfer, two series of compounds have been studied in detail and are often referred to: (i) EuIIIand TbIII polyaminocarboxylates for which the quantum yield upon ligand excitation becomes sizeable when ΔE(3ππ*-5DJ) > 2000 cm−1 [12]. When this gap is smaller, energy back transfer occurs (kback), and (ii) complexes with triphenylene-substituted calix[4]arenes for which the ideal ΔE(3ππ*-5DJ) gap is around 3500 cm−1 [13]. Note that E(3ππ*) refers to the zero-phonon transition.
Case 1.14
Published in Monica Fawzy, Plastic Surgery Vivas for the FRCS(Plast), 2023
Please describe your understanding of peripheral nerve anatomy.Neuronal cell bodies have dendrites to receive presynaptic neurotransmitters, and axonal projections that end in axonal terminals. They reside in:the dorsal root ganglia – with regard to sensory spinal nerves, andthe ventral spinal cord – with regard to motor spinal nerves.Connective tissues surrounding neuronal axons provide a vascularized connective tissue scaffold consisting of:the endoneurium, which encases each individual axon,the perineurium, which encases fascicles, andthe epineurium, which encases the nerve proper.The vasa nervorum provide nutrient blood supply to the axons. It originates in the epineurium, then branches in the perineurium, and forms a capillary plexus in the endoneurium.Myelinated nerves are ensheathed in a layer of myelin – produced by Schwann cells. This limits ionic transfer along the axon to the nodes of Ranvier, enabling saltatory conduction.
Study of stability and interference for catecholamines and metanephrines, 3-methoxytyramine: key point of an accurate diagnosis for pheochromocytoma and paraganglioma
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2021
Kaijuan Wang, Xiaojing Gao, Wei Zhang, Nian Sun, Lan Xie, Hongying Cong, Yutong Guo, Xiaocui Shi, Zhou Zhou
Analysis was performed by tandem mass spectrometry which consists of a Thermo U3000 high-pressure liquid chromatography and TSQ Endura mass spectrometer. An ACQUITY UPLC BEH Amide 2.1 × 100 mm, 2.5 μm XP column (Waters) was used for separation with a flow rate of 400 μL/min. The mobile water phase was made of DDW with 5% formic acid (A) and the organic phase of ACN with 5% formic acid (B). A gradient mode was used for analyte separation: 0 min, 15% A, 85% B; 2.5 min, 57.5% A, 42.5% B; 2.6 min, 15% A, 85% B; and 8 min, 15% A, 85% B. Ionization was carried out in positive mode with ion source spray voltage set at 3000 V, ion transfer tube temperature at 325 °C and vaporizer temperature at 300 °C. Sheath gas and Aux gas were set at 36 and10 Arb, respectively. Quantification was achieved by multiple reaction monitoring mode (MRM), including the following transitions: EPI: m/z 184.1→166.0 as quantifier peak, 184.1→107.0 as qualifier peak, and EPI-d6: m/z 190.3→172.0; NE: m/z 152.1→107.1 as quantifier peak, 152.1→135.0 as qualifier peak and NE-d6 m/z 158.1 →111.1; DA: m/z 154.1→91.1 as quantifier peak, 154.1→137.0 as qualifier peak and DA-d4: m/z 158.1→141.0; MN: m/z 180.1→148.0 as quantifier peak, 180.1→165.0 as qualifier peak and MN-d3: m/z 183.1→168.0; NMN: m/z166.1→134.0 as quantifier peak, 166.1→121.0 as qualifier peak and NMN-d3 m/z 169.1→137.1; 3-MT: m/z 151.1→91.1 as quantifier peak, 151.1→119.1 as qualifier peak and 3-MT-d4: m/z 155.1→95.1. Data were acquired and processed with the Analyst Software (TraceFinder 4.1, Thermo Scientific).
Limited penetration of cobalt and chromium ions into the cerebrospinal fluid following metal on metal arthroplasty: a cross-sectional analysis
Published in Clinical Toxicology, 2020
Meredith Harrison-Brown, Corey Scholes, Clarice Field, Robert McQuilty, Sami B. Farah, Ikram Nizam, Dennis Kerr, Lawrence Kohan
Baseline characteristics were summarised with descriptive statistics, and were assessed for normality (Anderson–Darling test) and equality of variance (multiple comparisons method) within implant groups. Confidence intervals were calculated where appropriate at the 95% level (95% CI), unless otherwise specified. Sex proportions and implant types (well-functioning implant and hip revision groups) were compared using χ2 analysis and age compared with an one-way Kruskal–Wallis analysis of variance (ANOVA) with a Dunn test for multiple comparisons. The duration the earliest implant was in situ was compared between well-functioning implant and hip revision groups with a Mann–Whitney t-test. The 75th percentile of CSF concentrations for the Control group was used to define the control threshold and the incidence of patients exceeding this range were compared between groups using χ2 analysis. Average metal concentrations were compared between the groups using Kruskal–Wallis ANOVA, with small differences in age between groups ignored as a covariate. To determine if ion transfer occurred between tissue compartments, trace element concentrations in plasma were converted to the percentage of joint fluid for each patient using Equation (1)
Investigation of pesticides on honey bee carbonic anhydrase inhibition
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Ercan Soydan, Ahmet Can Olcay, Gürkan Bilir, Ömer Taş, Murat Şentürk, Deniz Ekinci, Claudiu T. Supuran
Carbonic anhydrases (Cas, EC 4.2.1.1) are found in almost all living organisms and control pH and CO2/bicarbonate levels9. Many different CA isoenzymes have been identified in higher vertebrates, although these enzymes are less investigated in other species, such as the arthropods, including insects10–12. The physiological role of CA isozymes is to promote CO2 to HCO3− interconversion, thus, playing vital functions in various biochemical/physiological processes, including physiological pH regulation, gas balancing, calcification, photosynthesis, metabolism, etc9–12. Additionally, in vertebrates, CAs play a significant role in the eye, kidneys, central nervous system (CNS), inner ear, and many other organs, in terms of ion transfer, pH regulation, and metabolism13–15.