Search results for "Ketone"
showing 10 items of 337 documents
Glutamate permeability at the blood-brain barrier in insulinopenic and insulin-resistant rats
2009
The influence of diabetes on brain glutamate (GLU) uptake was studied in insulinopenic (streptozotocin [STZ]) and insulin-resistant (diet-induced obesity [DIO]) rat models of diabetes. In the STZ study, adult male Sprague-Dawley rats were treated with STZ (65 mg/kg intravenously) or vehicle and studied 3 weeks later. The STZ rats had elevated plasma levels of glucose, ketone bodies, and branched-chain amino acids; brain uptake of GLU was very low in both STZ and control rats, examined under conditions of normal and greatly elevated (by intravenous infusion) plasma GLU concentrations. In the DIO study, rats ingested a palatable, high-energy diet for 2 weeks and were then divided into weight …
Radiolucent Carbon Fiber–Reinforced Pedicle Screws for Treatment of Spinal Tumors: Advantages for Radiation Planning and Follow-Up Imaging
2016
Objective Surgical treatment of spinal tumors regularly includes spinal instrumentation with pedicle screws. Most modern pedicle screws are made of titanium alloy, which is associated with artifacts on postoperative imaging such as computed tomography and/or magnetic resonance imaging. These artifacts hamper radiation treatment planning and execution and follow-up imaging. Recently, carbon fiber–reinforced polyetheretherketone (CFRP) implants became available for posterior instrumentation with the aim to reduce imaging artifacts by implants. Methods Patients harboring spinal tumors underwent posterior stabilization using CFRP pedicle screws. Postoperative imaging was evaluated for implant a…
Enhancement of activities relative to fatty acid oxidation in the liver of rats depleted of l-carnitine by d-carnitine and a γ-butyrobetaine hydroxyl…
1995
Abstract This study was designed to examine whether the depletion of l -carnitine may induce compensatory mechanisms allowing higher fatty acid oxidative activities in liver, particularly with regard to mitochondrial carnitine palmitoyltransferase I activity and peroxisomal fatty acid oxidation. Wistar rats received d -carnitine for 2 days and 3-(2,2,2-trimethylhydrazinium)propionate (mildronate), a non-competitive inhibitor of γ-butyrobetaine hydroxylase, for 10 days. They were starved for 20 hr before being sacrificed. A dramatic reduction in carnitine concentration was observed in heart, skeletal muscles and kidneys, and to a lesser extent, in liver. Triacylglycerol content was found to …
Manganese(iv) oxamato-catalyzed oxidation of secondary alcohols to ketones by dioxygen and pivalaldehyde
1998
A new manganese(IV) oxamato complex possessing a bis(moxo) dimanganese core has been synthesized, magnetically and structurally characterized, and found to catalyze the aerobic oxidation of secondary alcohols to ketones with cooxidation of pivalaldehyde to pivalic acid with good yields and high selectivities. Ruiz Garcia, Rafael, Rafael.Ruiz@uv.es ; Fernandez Picot, Isabel, Isabel.Fernandez@uv.es ; Pedro Llinares, Jose Ramon, Jose.R.Pedro@uv.es ; Rosello Arce, Antonio Luis, Antonio.L.Rosello@uv.es ; Castro Bleda, Isabel, Isabel.Castro@uv.es
Mechanical behavior of provisional implant prosthetic abutments
2014
Introduction: Implant-supported prostheses have to overcome a major difficulty presented by the morphology and esthetics of peri-implant tissues in the anterior sector. Diverse therapeutic techniques are used for managing the mucosa adjacent to the implant and the most noteworthy is immediate/deferred fixed provisionalization. Objectives: In vitro testing of strength and deformation of implant prosthetic abutments made from different materials (Titanium/PEEK/methacrylate). Material and Methods: Forty Sweden&Martina® implant prosthetic abutments (n=40) were divided into five groups: Group MP: methacrylate provisional abutments with machined titanium base; Group PP: Poly ether ether ketone (P…
Enhanced Conductivity of Composite Membranes Based on Sulfonated Poly(Ether Ether Ketone) (SPEEK) with Zeolitic Imidazolate Frameworks (ZIFs)
2018
The zeolitic imidazolate frameworks (ZIFs) ZIF-8, ZIF-67, and a Zn/Co bimetallic mixture (ZMix) were synthesized and used as fillers in the preparation of composite sulfonated poly(ether ether ketone) (SPEEK) membranes. The presence of the ZIFs in the polymeric matrix enhanced proton transport relative to that observed for SPEEK or ZIFs alone. The real and imaginary parts of the complex conductivity were obtained by electrochemical impedance spectroscopy (EIS), and the temperature and frequency dependence of the real part of the conductivity were analyzed. The results at different temperatures show that the direct current (dc) conductivity was three orders of magnitude higher for composite …
Laser densification of organic coating: Effects of laser wavelength, operating parameters and substrate properties
2012
International audience; Mechanical bonding and interface behaviour play a key role for any materials deposited on different substrates. Usually, a post-spray heat treatment is required to improve the coating morphology and to enhance mechanical properties of thermal-sprayed polymeric coating. The effects of YAG, CO2 and diode laser radiations on as-sprayed PEEK coating deposited on stainless steel and aluminum substrates were investigated. The results revealed a good coating densification and interface behavior. A correlation between coating and substrate absorption coefficients, their thermophysical properties and laser operating parameters was shown. Besides, the finite element modeling b…
Amorphous and crystalline polyetheretherketone: Mechanical properties and tissue reactions during a 3-year follow-up.
2007
The study was aimed to test the mechanical strength, structural stability, and tissue reactions of optically amorphous and crystalline polyetheretherketone (PEEK) plates during a 3-year follow-up in vivo and in vitro. The injection-moulded PEEK plates were implanted to the dorsal subcutis of 12 sheep, which were sacrificed at 6-156 weeks. Thereafter, the plates were subjected to tensile tests, and levels of crystallinity were assessed by differential scanning calorimetry (DSC). Histological evaluation was carried out using the paraffin technique. In vitro properties were examined with the tensile test and DSC at 0-156 weeks. Tissue reactions were mild and fairly similar for the amorphous an…
The use of emulsions in the preparation of samples and standards for analysis by atomic-absorption spectroscopy determination of Cu and Fe in mibk ex…
1984
The use of aqueous/organic emulsions is shown to give advantages in the AAS determination of Cu and Fe extracted as their pyrrolidinedithiocarbamate complexes into methyl isobutyl ketone. The emulsions are more stable than the extracts, and the standards can be prepared from aqueous solutions by emulsification, but without extraction.
Improved Regioselectivity in Pyrazole Formation through the Use of Fluorinated Alcohols as Solvents: Synthesis and Biological Activity of Fluorinated…
2008
The preparation of N-methylpyrazoles is usually accomplished through reaction of a suitable 1,3-diketone with methylhydrazine in ethanol as the solvent. This strategy, however, leads to the formation of regioisomeric mixtures of N-methylpyrazoles, which sometimes are difficult to separate. We have determined that the use of fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation, and we have used this modification in a straightforward synthesis of fluorinated analogs of Tebufenpyrad with acaricide activity. Fil: Fustero, Santos. Universidad de Valencia; España Fil…