bluuebunny/crossref_metadata_2025_split huggingface dataset:
Release and chemical speciation of copper from anti‐fouling paints with different active copper compounds in artificial seawater
Authors: Sandberg J. , Odnevall Wallinder I. , Leygraf C. , Virta M. 
Published: March 2007

AbstractRelease rates of total copper in artificial seawater (without organic matter) from anti‐fouling paints of different active copper compounds range from 0.5 to 75 μg cm−2 day−1. Approximately 80% of the released total copper was determined to be electrochemically active (labile fraction) for all paints investigated. The remaining fraction is more strongly bonded non‐bioavailable copper complexes with species released from the paints. Model calculations, using MinteqA2, predicted only a small portion (≈ 6%) of the total copper released as free cupric ions (Cu(H2O)2+6), the most bioavailable form of copper. Similar results were obtained with bioassay testing using bacteria and yeast on released copper from massive copper sheet exposed at identical conditions. The large difference between the total and the bioavailable copper fraction emphasizes the importance of generating chemical speciation data for accurate decisions of potential adverse effects of copper release from anti‐fouling paints. The observed release of other metals and organic substances from the paint matrix, implies the importance to assess an integrated response from released species from paints of anti‐fouling, and not only from single ingredients.
Influence of fluoride concentration and pH on corrosion behavior of Ti‐6Al‐4V and Ti‐23Ta alloys in artificial saliva
Authors: Robin A. , Meirelis J. P. 
Published: March 2007

AbstractTitanium alloys exhibit an excellent corrosion resistance in most aqueous media due to the formation of a stable oxide film and some of these alloys (particularly Ti‐6Al‐4V) were chosen for surgical and odontological implants for this resistance and their biocompatibility. Treatments with fluorides (F−) are known as the main method to prevent plaque formation and dental caries. Toothpastes, mouthwashes and prophylactic gels can contain from 200 to 20 000 ppm F− and can present neutral to acidic character, which can affect the corrosion behavior of titanium alloys devices present in the oral cavity. In this work, the behavior of Ti‐6Al‐4V and the new experimental Ti‐23Ta has been evaluated in artificial saliva of pH 2, 5 and 7 and different F− concentrations (0, 1000, 5000 and 10 000 ppm), through open‐circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy. A defined correlation between pH and F− concentration settled the active or passive character of the materials. For both alloys, an active behavior was observed for pH 2 and 1000 to 10 000 ppm F− and for pH 5 and 5000 and 10 000 ppm F−. The passive behavior was observed for the other investigated conditions. The F− concentration increase and pH decrease reduced the corrosion resistance of the alloys and decreased the stability of their passive film. The corrosion behavior of both alloys was very similar, but the Ti‐23Ta alloy generally presented slightly higher corrosion resistance.
Intravascular heparin protects muscle flaps from ischemia/reperfusion injury
Authors: Li Xiaolu , Cooley Brian C. , Fowler J. David , Gould John S. 
Published: March 2007

AbstractHeparin has been found to decrease ischemia/reperfusion injury in skeletal muscle and other tissue/organ systems. The timing of heparin administration to the muscle vasculature has not been explored. We investigated the use of heparinized blood as a washout solution during ischemia to reduce ischemia/reperfusion injury. A rat cutaneous maximus muscle free flap was subjected to a 10‐hr period of room temperature ischemia, then was heterotopically transplanted to the groin via microsurgical revascularization to the femoral vessels. In three experimental groups, flaps were subjected to brief ex vivo perfusion with autologous heparinized blood, at 2, 5, or 8 hr into the 10‐hr ischemic interval. In the two other groups, the flaps were not perfused, and the animals were systemically heparinized either before ischemia or before transplantation, respectively. A control group underwent no flap perfusion or systemic heparinization. After transplantation, flaps were given a 48‐hr period of in vivo reperfusion, then were harvested for evaluation. Flaps undergoing ex vivo perfusion or preischemic heparinization had no significant differences in weight gain (edema) compared with flaps receiving posttransplant heparinization or no heparinization (controls). The dehydrogenase staining of muscle biopsies was significantly faster (indicative of viable tissue) for perfused flaps and the flaps for which the animals received preischemic heparinization, when compared with flaps for which the animals received posttransplant heparinization or no heparinization. From these results, we conclude that heparin offers protection from ischemia/reperfusion injury when it can be introduced into the vascular network either prior to or during the ischemia period. These findings suggest the possibility of using heparinized washout solutions to enhance survival in amputated extremities. © 1995 Wiley‐Liss, Inc.
Natural history of digital replantation: A 12‐year prospective study
Authors: Povlsen B. , Nylander G. , Nylander E. 
Published: March 2007

AbstractThe purpose of the study was to evaluate the fate of the digital arterial anastomoses, resting total digital blood flow, and cold‐induced discomfort following digital replantation with two repaired arteries. The evaluation was done with a Doppler ultrasound of the anastomoses, temperature recording from the finger pulp at room temperature, and a questionnaire regarding the patient's impression of cold‐induced discomfort. At the 2‐year follow‐up all anastomoses were patent, but in two of the six patients one anastomosis was occluded at the 12‐year follow‐up. The replanted digits generally showed lower skin temperatures compared with controls at the 2‐year follow‐up but these had normalized 10 years later, even in digits with one of the two repaired arteries occluded. The number of patients with severe cold‐induced discomfort was unchanged during the observation period. Conclusions: The digital flow continues to increase after the first 2 years after replantation and may reach normal levels at room temperature; however, cold‐induced discomfort is not normalized. Total blood flow improvement is not affected by late arterial occlusion. © 1995 Wiley‐Liss, Inc.
Orthotopic liver retransplantation in rats
Authors: Goto Shigeru , Kamada Naoshi , Delriviere Luc , Kobayashi Eiji , Lord Roger , Ware Frances , Hara Yuzuru , Edwards‐Smith Catherine , Shimizu Yoshinori , Vari Frank 
Published: March 2007

AbstractA surgical experience with a method of rat orthotopic liver retransplantation (OLRT), and a preliminary study of immunological responses after OLRT are reported. OLRT was performed on the same recipient after the first orthotopic liver transplantation (1st‐OLT) according to our original (Kamada's) cuff method. Replacement of the portal vein (PV) and infra‐hepatic vena cava (IHVC) cuffs was not technically difficult. However, there were no survivors from the first 6 retransplanted rats, mainly due to complications from defective supra‐hepatic vena cava (SHVC) anastomoses. Unlike the human intra‐abdominal SHVC, the posterior wall of the intraabdominal SHVC in rats is too short and fragile to perform an end‐to‐end anastomosis twice between donor and recipient SHVC. For a second group of seven retransplants, a modification of the SHVC anastomosis was made between donor and recipient SHVC in conjunction with the recipient's cuff diaphragm. This enabled reanastomosis to be secure, resulting in the improved 1‐week survival after isogeneic OLRT (85.7%). This OLRT model has been applied to the fully allogeneic combination for several immunological studies and led to novel findings. Thus, an experimental model of a rat orthotopic liver retransplant model has the potential to allow more valuable insights into the immunological study of chronic rejection, sensitization and chimerism following liver retransplantation. © 1995 Wiley‐Liss, Inc.
Derivative lymphatic microsurgery: Indications, techniques, and results
Authors: Campisi C. , Boccardo F. , Alitta P. , Tacchella M. 
Published: March 2007

AbstractMicrosurgical derivative procedures to treat chronic lymphedemas of the limbs are reported here. Techniques used consisted of lymphatic capsule‐venous anastomoses (in pediatric patients) and end‐to‐side lymphatic‐venous anastomoses. Results after more than 5 years showed improvement in about 70% of the cases. The importance of an accurate preoperative diagnostic evaluation and the precise indications for these microsurgical procedures are discussed. Some personal modifications of derivative microsurgical techniques and their advantages are also pointed out. © 1995 Wiley‐Liss, Inc.
Refinements in the one‐stage procedure for management of chronic osteomyelitis
Authors: Guelinckx Paul J. , Sinsel Nadja K. 
Published: March 2007

AbstractPosttraumatic osteomyelitis remains a frequent problem and requires aggressive surgical treatment to be cured. Radical debridement of all involved soft and hard tissues, obliteration of dead space, and neovascularization of the involved area are obligatory for successful management of the disease. Microvascular free tissue transfer provides the necessary tissue bulk and neovascularization to reconstruct the resulting defect. The transplanted muscle can be optimally mobilized and adjusted in size to obliterate the dead space in contrast to local transposition flaps. This is facilitated by smoothening the bony cavity using a rotating drill system. With an optimal interface between the muscle and the wall of the cavity, small foci of infection can be eliminated. Moreover after free muscle transfer, the optimal environment for secondary bone reconstruction is created. These principles of radical debridement combined with muscle transfer for dead space obliteration, are generally accepted in literature. Nevertheless to achieve this goal several different treatment schedules of repetitive debridements, prolonged antibiotic regimes, and finally various flap transfers have been advocated. We present 16 patients with chronic osteomyelitis treated with radical debridement and immediate free muscle transfer using the latissimus dorsi muscle preferably. Postoperatively an antibiotic course of only 12 days was given. With a mean follow‐up of 2 years all patients remained symptom free. Therefore, our results indicate that this long‐term problem can be solved by a one‐stage procedure using a free flap combined with a short course of antibiotics. However definite conclusions should be reserved for 20 years. © 1995 Wiley‐Liss, Inc.
Volumetric NMR imaging with time‐varying gradients
Authors: Macovski Albert 
Published: March 2007

AbstractA novel generalized processing system is described whereby, using time‐varying gradients, simultaneous data acquisition can be provided for all points in a volume. This is in sharp distinction to the sensitive‐point method where only the null region is imaged. It is shown that time‐varying gradients systems provide unique phase modulation functions which, when appropriately decoded, enable every point in the volume to be simultaneously imaged from a single FID signal. Methods are shown using the technique to provide simultaneously acquired, localized NMR spectra. Alternative gradient signals are considered including both periodic and aperiodic waveforms.
Design data for efficient axial gradient coils: Application to NMR imaging
Authors: Saint‐Jalmes Hervé , Taquin Jacques , Barjhoux Yves 
Published: March 2007

AbstractA new design for an axial magnetic field gradient is described. Implemented in a four‐coil configuration, it requires far less power than the conventional Maxwell pair, while maintaining the same field linearity. A practical design tool with a set of curves giving coil dimensions is proposed. Two realizations dedicated to NMR imaging are described and compared with the equivalent Maxwell pair. Substantial power reductions are achieved; in these cases, dc power is reduced by a factor of 5 and switching power by a factor of 15.
Magnetic field dependence of solvent proton relaxation in aqueous solutions of Fe3+ complexes
Authors: Koenig Seymour H. , Baglin Coral M. , Brown Rodney D. 
Published: March 2007

AbstractIt might appear that the Fe3+ ion would be particularly useful as an agent for enhancing contrast in NMR images since it has a relatively large magnetic moment and occurs in vivo in a variety of forms. Moreover, the concentration of Fe3+ changes locally in certain disease states (e. g., β‐thalassemia) and in trauma (formation of methemoglobin), and can be altered in the gastrointestinal tract by the ingestion of readily available dietary supplements. However, the Fe3+ ion is insoluble above pH ∼ 4, and soluble chelate and protein complexes of Fe3+ tend to sequester the ions from solvent; hence, the efficacy of Fe3+ ions for relaxing water protons ought to be low under typical physiological conditions. We report the magnetic field dependence of the relaxation rate of solvent protons (NMRD profiles) for solutions of a variety of Fe3+ complexes to demonstrate the phenomenology relevant to NMR imaging. From these data we make some estimates to show that, deposite the low relaxation rates of solvent protons in solutions of Fe3+ complexes, certain observed changes in image contrast are consistent, quantitatively, with inferences that can be drawn from solution data.
31P Surface‐Coil NMR Analysis of Metabolic Status in KHJJ Tumors
Authors: Adams Dorothy A. , Denardo Gerald L. , Denardo Sally J. , Conboy Claire B. , Morton Bradbury E. 
Published: March 2007

AbstractNoninvasive monitoring of the effects of treatment on cancer tissue is fundamental to the development of rational radioimmunotherapy (RIT) schemes employing radiolabeled monoclonal antibodies or antibody fragments specific for human cancer. Recent advances in nuclear magnetic resonance spectroscopy make it an attractive candidate for sequential, topical monotoring by 31P NMR of metabolic events during RIT. Preliminary to this effort, we examined the metabolic competence of the well‐characterized, murine KHJJ tumor in situ in BALB/c mice using 31P surface‐coil NMR. The ATP/Pi ratio in tumor volumes ranging from 100 to 800 mm3 showed that tumors over this range of sizes were able to maintain high levels of ATP relative to Pi. As the tumor volume increased above 1 cm3, ATP/Pi levels indicated poor metabolic competence. This lack of metabolic competence was correlated with histological evidence of tissue necrosis and vascular disintegration. The T1 values of assigned phosphorus metabolites were established. Intracellular pH, as determined from the chemical shift of Pi, was found to vary in these tumors from 7.1 in rapidly metabolizing tissue to 6.6 in necrotic tumors.© 1985 Academic Press,Inc.
Truncation Artifacts in Magnetic Resonance Imaging
Authors: Wood Michael L. , Mark Henkelman R. 
Published: March 2007

AbstractA method has been developed to reduce a magnetic resonance image artifact arising from the Fourier transformation of data truncated in the phase‐encoding direction. The discontinuity is eliminated between the phase of the complex data sample associated with the maximum negative phase‐encoding gradient and the phase of the maximum positive gradient sample. Images retain sharper edges than if low‐pass filtering is employed. The method is demonstrated on clinical images, then an explanation of the method is presented.© 1985 Academic Press,Inc.
Time‐Multiplexed Multislice Inversion‐Recovery Techniques for NMR Imaging
Authors: Park H. W. , Cho M. H. , Cho Z. H. 
Published: March 2007

AbstractMultislice imaging techniques effectively applicable to inversion‐recovery (IR) imaging are developed and applied to human imaging. These new multislice IR imaging sequences employ the time‐multiplexing (TM) technique conventionally used in the slice‐by‐slice saturation‐recovery (SR) imaging. Two new time‐multiplexed multislice (TMM) IR imaging sequences are proposed and some of the experimental results obtained with the methods are presented.© 1985 Academic Press,Inc.
Water suppression in 1H magnetic resonance images by the generation of multiple‐quantum coherence
Authors: Dumoulin Charles L. , Vatis Dimitrios 
Published: March 2007

AbstractPulse sequences which generate multiple‐and zero‐quantum coherence and suppress the detection of single‐quantum coherence have ben used to greatly reduce the intensity of the water signal in NMR images. In the experiment, image signals having multiple‐quantum behavior add constructively while single‐quantum signals, such as the signal arising from water, are canceled. Since the generation of multiple‐quantum coherence is only a function of spin‐spin coupling, water suppression by this technique is independent of chemical shift. Consequently, suppression of the water resonance in a 1H NMR image can be accomplished in an inhomogeneous magnetic field provided that the excitation profile of the rf pulses is equal for all spins. Furthermore, variations in the T1 and T2 of coupled and uncoupled spins do not affect the efficiency of the multiple‐quantum filter. © 1986 Academic Press, Inc.
Rapid NMR imaging of dynamic processes using the FLASII technique
Authors: Frahm Jens , Haase Axel , Matthaei Dieter 
Published: March 2007

AbstractFLASH (Fast Low‐Angle SHot) imaging is a new method for rapid NMR imaging which has been demonstrated to provide abdominal images without artifacts due to respiratory or peristaltic motions. The sequence typically employs 15° radiofrequency excitation pulses and acquires a free induction decay signal in the form of a gradient echo. Here FLASH images are recorded in the presence of dynamic processes with time constants even smaller than the measuring time of about 2 s for an image with a 128 × 128‐pixel resolution. Experiments are carried out on flow phantoms and on rabbits yielding heart images without gating of the cardiac motion. © 1986 Academic Press, Inc.
Observation of intracellular potassium and sodium in the heart by NMR: A major fraction of potassium is “invisible”
Authors: Fossel Eric T. , Hoefeler Herbert 
Published: March 2007

AbstractUsing 39K and 23Na NMR in conjunetion with extracellularly localized shift reagents, we have determined the intracellular concentrations of NMR visible sodium and potassium in isolated, perfused rat hearts. We find this concentration to be 9.9 mM/kg cell water for sodium and 31 mM/kg cell water for potassium. Values of activity determined by ionsensitive microelectrodes are in good agreement with our sodium value but do not agree with our potassium value. Our results mean that a major pool of intracelluar potassium is, on average, signifieantly immobilized and that the mobile NMR visible faction (31mM/kg) is not in exchange with the NMR invisible pool (114mM/kg). The immobilized fraction is characterized by T2 values which are too short to be observed by our conventional spectrometer. This fraction is, therefore, said to be “invisible” under our experimental conditions. © 1986 Academic Press, Inc.
Myocardial high energy phosphate metabolism in closed chest dog: Creation of an animal model
Authors: Osbakken Mary , Ligeti Laszlo , Clark B. J. , Bolinger Lizann , Subramanian Hari , Schnall Mitchell , Leigh Jack , Chance Britton 
Published: March 2007

AbstractA chronic closed chest dog model was developed to study myocardial metabolism with NMR spectroscopy. Cardiac windows were surgically created in 10 dogs by removal of two ribs and accompanying skeletal muscle. Marlex mesh was sewn between the two exposed ribs, and fascia and skin were closed. 31P spectra were obtained using a surface coil placed into the surgically created pouch and using routine NMR pulsing techniques. © 1986 Academic Press, Inc.
Cardiac transfer function relating energy metabolism to workload in different species as studied with 31P NMR
Authors: Ligeti Laszlo , Osbakken Mary D. , Clark Bernard J. , Schnall Mitchell , Bolinger Lizann , Subramanian Hari , Leigh Jack S. , Chance Britton 
Published: March 2007

AbstractCardiac metabolism was studied with 31P NMR in 7 dogs and 4 cats to determine whether animals adapted for different life‐styles (stalk and sprint vs endurance running) respond to increased work loads (heart rate × blood pressure product) with different high‐energy phosphate kinetics. Hearts were exposed via a left lateral thoracotomy under Nembutal anesthesia (40 mg/kg). Two‐turned solenoid surface coils were placed on the left ventricles; pacing wires were sutured into the left ventricular apeces. The femoral artery and vein were canulated for blood pressure and arterial blood gas monitoring and fluid and drug infusion, respectively. Animals were placed in a plexiglass holder into a 2.1‐T, 31‐cm‐bore, superconducting magnet. 31P spectra were obtained from the heart using respiratory and electrocardiogram gating. Cardiac work loads were changed by pacing the heart at 4, 4.5, and 5 Hz. Heart rate × blood pressure product “work” was correlated with Pi/PCr ratios. Dog hearts were more resistant than those of cats to changes in Pi/PCr with increasing work load. It is possible that animals adapted to different life‐styles may have cardiovascular systems which are metabolically and mechanically adapted for different forms of stress. These differences may be elicited and effectively delineated using in vivo NMR techniques during various physiological interventions, such as pacing. The basis for these differences may be related to cardiac microvasculature or to intrinsic differences in enzyme kinetics. Delineation of these mechanisms may be helpful in the understanding of the physiological basis of cardiac function in health and disease. © 1987 Academic Press. Inc.
Frequency‐modulated radiofrequency pulses in spin‐echo and stimulated‐echo experiments
Authors: Kunz Dietmar 
Published: March 2007

AbstractFrequency‐modulated of pulses based on a linear frequency sweep are studied experimentally in spin‐echo and stimulated‐echo sequences. It turns out that these FM pulses generate a quadratic phase perpendicular to the selected slice and that the quadratic phases of the FM pulses in a spin‐echo or stimulated‐echo sequence may compensate each other if sweep velocity and gradients are suitably chosen. For a complete rephasing, a formula is given and supported by measured slice profiles. Slice profiles of excellent rectangularity are obtained. Finally, it is shown that with this technique images can be obtained using pulses of increased bandwidth and reduced peak power compared with the AM situation. © 1987 Academic Press, Inc.
SYS‐FLASH. Systemic saturation in FLASH MR imaging
Authors: Matthaei Dieter , Haase Axel 
Published: March 2007

AbstractA simple modification of FLASH (Fast Low Angle SHot) MR imaging, which results in a variable reduction of the intensity of flowing blood and flow artifacts in transaxial tomograms, is reported. Here a nonselective radiofrequency pulse of variable flip angle is used before the acquisition of each projection in FLASH imaging to saturate flowing blood within the whole volume (Systemic Saturation = SYS‐FLASH). © 1987 Academic Press, Inc.