bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser ureteral anastomosis using intraluminal albumin stent in a porcine model
Authors: Xie Hua , Shaffer Brian S. , Prahl Scott A. , Gregory Kenton W. 
Published: April 2003

AbstractBackground and ObjectivesWe compared ureteral anastomosis using a laser and intraluminal albumin stent with both conventional suturing and laser soldering techniques.Study Design/Materials and MethodsTwelve pigs underwent bilateral ureteral anastomoses (N = 24) using one of the three anastomotic methods: (1) laser welding with intraluminal albumin stent (N = 11); (2) with albumin solder (N = 8); and (3) conventional suturing (N = 5). Operative parameters, leakage rate, intrapelvic perfusion pressure, urography, and histology of the anastomoses were examined.ResultsOperative time for ureteral anastomosis in the stent and solder groups were significantly shorter than the suture group (means 370 seconds and 360 vs. 710 seconds, both P = 0.02). Leakage rate of the anastomoses was lower in the stent group (9%, 1/11) as compared to the solder group (25%, 2/8). The Whitaker test showed that the intrapelvic perfusion pressure elevated gradually after anastomosis and significantly increased at 4 weeks postoperatively in all three methods. Various degrees of hydronephrosis were also noticed in three groups after 4 weeks of surgery.ConclusionsUse of the intraluminal albumin stent increased the reliability of laser welding for ureteral anastomosis. The clinical significance of using this technique should be investigated further. Lasers Surg. Med. 32:294–298, 2003. © 2003 Wiley‐Liss, Inc
Effects of low intensity infrared laser radiation on the water transport in the isolated toad urinary bladder
Authors: Franco Wilson , Leite Renner S. , Parizotto Nivaldo A. 
Published: April 2003

AbstractBackground and ObjectivesThe aim of this work was to study the effects of low intensity laser radiation on water transport in the toad bladder in vitro.Study Design/Materials and MethodsThe water flow through the membrane was measured gravimetrically in bag preparations of the membrane.ResultsLaser radiation did not alter the water transport in the presence nor in the absence of vasopressin. In contrast, when the hemibladders were previously treated with vasopressin, the laser decreased by approximately 33.70% arginine‐vasopressin (AVP)‐mediated water transport. Laser radiation increased 3′5′‐cyclic adenosine monophosphate (3′5′‐cAMP) mediated water transport by approximately 23%. The association of laser radiation with indomethacin (IND) did not affect AVP‐mediated water transport.ConclusionsThis data suggests that the laser may have two effects on AVP‐mediated water transport: one inhibitory effect on 3′5′‐cAMP synthesis by inhibiting the adenylate cyclase complex and another stimulatory effect by inhibiting nucleotide‐phosphodiesterase activity. Our results also indicate that the laser does not interfere in the prostaglandins biosynthesis induced by AVP. Lasers Surg. Med. 32: 299–304, 2003. © 2003 Wiley‐Liss, Inc.
Non‐invasive monitoring of commonly used intraocular drugs against endophthalmitis by raman spectroscopy
Authors: Hosseini K. , Jongsma F.H.M. , Hendrikse F. , Motamedi M. 
Published: April 2003

AbstractPurposeTo develop a non‐contact and non‐invasive method for quantification of the local concentration of certain antibiotic and antifungal drugs in the eye.Study Design/Materials and MethodsAn integrated CCD‐based Raman spectroscopic system designed specifically for ophthalmic applications was used to non‐invasively detect the presence of ceftazidime and amphotericin B in ocular media. Specific Raman signatures of the above named drugs were determined for various concentrations that were injected through a needle in the aqueous humor of rabbit eyes in vivo. Raman spectra were subsequently acquired by focusing an argon laser beam within the anterior chamber of the eye.ResultsCompared to ocular tissue, unique spectral features of ceftazidime appeared near 1,028, 1,506, 1,586, and 1,641 cm−1. Amphotericin B exhibited its characteristic peaks at 1,156.5 and 1,556 cm−1. The amplitude of the spectral peak corresponding to these drugs (acquired by 1 second exposure time and 25 mW of laser power) were determined to be linearly dependent on their local concentration in the anterior chamber of the eye.ConclusionsRaman spectroscopy may offer an effective tool to non‐invasively assess the local concentration of the delivered drugs within the ocular media. This technique potentially could be used to investigate the pharmacokinetics of intraocular drugs in vivo either from a releasing implant or a direct injection. Lasers Surg. Med. 32:265–270, 2003. © 2003 Wiley‐Liss, Inc.
Treatment of lupus erythematosus with pulsed dye laser
Authors: Baniandrés Ofelia , Boixeda Pablo , Belmar Paulina , Pérez Alejandro 
Published: April 2003

AbstractBackground and ObjectivesThe treatment of cutaneous lupus erythematosus (CLE) with dye and argon laser has been evaluated in a number of articles in recent years. The improvement of telangiectasias and chronic erythema of the cutaneous lesions was based on the selective photothermolysis ablation of the dilated capillaries and venules.Study Design/Materials and MethodsWe describe the results of the treatment of cutaneous lesions of 14 patients; eight with discoid lupus erythematosus (DLE) and six with systemic lupus erythematosus (SLE). Three patients received a treatment with flashlamp pulsed dye laser (FPDL) (585 nm, 450 microseconds) with fluences in the range from 5 to 7.75 J/cm2; the other 11 patients were treated with long pulsed dye laser (LPDL) (595 nm, 1.5–10 milliseconds) with fluences in the range from 6 to 13 J/cm2 depending on the pulse duration.ResultsDuring a median follow‐up of 10 months, we observed an average improvement in over 60% of the lesions. A few side effects were observed in all patients: four had transient hyperpigmentation and one patient had light scarring. Three patients had a relapse after more than 1 year; they were then offered conventional treatment.ConclusionsWe confirm that pulsed dye laser is a good alternative treatment for the erythema in active cutaneous lesions of lupus erythematosus (LE). Lasers Surg. Med. 32:327–330, 2003. © 2003 Wiley‐Liss, Inc.
In vitro assessment and monitoring of the implant titanium materials – physiological environment interactions
Authors: Popa M. V. , Vasilescu E. , Drob P. , Demetrescu I. , Popescu B. , Ionescu D. , Vasilescu C. 
Published: April 2003

AbstractLong‐term monitoring (for 8000 exposure hours) of titanium and its implant alloys (Ti‐5Al‐4V, Ti‐6Al‐4Fe) interactions with Ringer's solutions of different pH‐values (2.5, 4.35, 6.98), simulating various conditions that can appear at the contact between implant and tissues was carried out in this paper. All data were statistics treated using Medcalc program. In vitro electrochemical behaviour of titanium and its alloys reveals their self‐passivation in Ringer's solutions. Monitoring of the open circuit potentials with time and pH have shown that the passive films on the implant materials studied were very stable for all tested periods. Interactions due to the non‐uniformity of the physiological electrolyte pH can not produce any form of local corrosion. The tested materials present low corrosion rates which attest their very good stability for 8000 exposure hours in simulated biological environment. Surface topography characterisation using atomic force microscopy (AFM) data, correlated with the electrochemical parameters, were arguments for the stability of the samples in studied bioliquids.
Copper corrosion inhibition by fast green, fuchsin acid and basic compounds in citric acid solution
Authors: Cano E. , Pinilla P. , Polo J. L. , Bastidas J. M. 
Published: April 2003

AbstractFast green (FG), fuchsin basic (FB) and fuchsin acid (FA) were studied as copper corrosion inhibitors in citric acid solution. Five citric acid concentrations were tested from 0.001 to 1.0 M. Twelve FG, FB and FA concentrations were studied from 1 × 10−5 to 1 × 10−1 M, at four temperatures from 298 to 328 K. The gravimetric method was employed to study the protective effect of FG, FB and FA. The order of inhibition efficiency was FB > FA > FG. Conventional adsorption isotherms were tested to fit the experimental data. The best fit was obtained using the Frumkin isotherm model. A thermodynamic/kinetic model of adsorption was also fitted. The projected molecular area of the inhibitors was calculated to elucidate inhibitor orientation in the adsorption process.
Development of corrosion sensors for monitoring steel‐corroding agents in reinforced concrete structures
Authors: Lee H. S. , Shin S. W. , Ahn J. M. , Kim Y. C. , Kho Y. T. 
Published: April 2003

AbstractCorrosion sensors were devised to develop a system whereby the depth of chloride permeation from concrete surfaces can be monitored non‐destructively on a real‐time basis using such sensors embedded in cover concrete of reinforced concrete structures. The proposed corrosion sensors were subjected to accelerated corrosion in NaCl solutions, mortar specimens intrinsically containing chlorides, and mortar specimens impregnated with chloride solutions, while recording the changes in the resistance readings. The resistance of sensors increased as the degree of corrosion increased. The time to the first change in the resistance decreased and the corrosion degree and resistance increased as the chloride concentration increased and as the distance from mortar surfaces decreased. It was therefore confirmed that the corrosion sensors are capable of monitoring the depth of chloride permeation with sufficient accuracy.
Study of colored anodized aluminum with calcon in sulfuric acidic solution using cyclic voltammetry and impedance measurement methods
Authors: Norouzi P. , Ganjali M. R. , Golmohamaddi M. , Mousavi S. , Vatankhah G. 
Published: April 2003

AbstractThe effect of coloring condition of Al with Calcon (sodium 2,2'‐dihydroxy‐azonaphthalene‐4‐sulfonate), on the corrosion resistance of Al in 0.1 M sulfuric acid solution was studied, using cyclic voltammetry and measurement of impedance noise methods. The changes in the corrosion resistance of colored aluminum electrodes were evaluated by measuring the magnitude of impedance and cyclic voltammetric responses of anodized and colored electrodes. An irreversible corrosion response was observed at the cyclic voltammogram of the colored aluminum electrode. The current and threshold potential of corrosion responses strongly depends on the applied conditions during anodizing, coloring and sealing stages. In addition, significant changes in impedance at the ac voltammogram and noise level at some ac frequencies were observed, when the electrodes were colored under various conditions. In this regard, the surface of the electrode was studied by Scanning Electron Microscopy (SEM). Comparison of SEM images of the colored and uncolored aluminum specimens showed that the colored surface contained a significant numbers of pits. The results indicated that coloring aluminum with Calcon could reduce corrosion resistance of aluminum and increase roughness of the oxide film.
Corrosion process of silver in environments containing 0.1 ppm H2S and 1.2 ppm NO2
Authors: Kim H. 
Published: April 2003

AbstractThe effects of sub‐ppm levels of nitrogen dioxide and hydrogen sulfide, and the adsorbed water on the corrosion of silver were studied in order to get a better understanding of the atmospheric corrosion process. An in situ mass balance was taken to monitor the kinetic behavior and the surface and the corrosion film were analyzed by X‐ray photoelectron spectroscopy (XPS).In H2S environments, the tarnish film consisted of silver sulfide, and the corrosion rate depended upon oxygen as well as relative humidity. Silver was oxidized by only oxygen and the corrosion behavior conformed to a type of a parabolic law. In NO2environments, the corrosion film consisted of nitrate and oxide, and the corrosion rate depended upon oxygen as well as relative humidity. Compared to hydrogen sulfide, the formation of silver nitrate being strong hydroscopic reduced the effect of humidity on corrosion rate. In H2S + NO2environment, the corrosion process was independent of both oxygen and humidity, and the kinetic behavior conformed to a linear law. The difference of corrosion process between H2S or NO2environments and H2S + NO2environments is thought to be due to the role of nitrogen dioxide as an ionic conductor and the presence of strong oxidizing species such as elemental sulfur which can be produced from the following reaction: H2S + 2NO2→ S + 2HNO2. In addition, the role of adsorbed water affecting atmospheric corrosion process was mentioned based on the amount of adsorbed water from the three types of exposure environments.
Corrosion inhibition of steel in crude oil storage tanks
Authors: Khalifa M. A. , El‐Batouti M. , Mahgoub F. , Bakr Aknish A. 
Published: April 2003

AbstractThe corrosion behavior of steel in water from certain oil fields with various organic inhibitors was studied by applying potentiodynamic technique at pH 5.9. The inhibitors which were used include 2‐methylbenzimidazole (I), 2‐mercaptobenzimidazole (II), 2‐mercapto‐5‐methylbenzimidazole (III), and 2‐mercaptothiazole (IV). The inhibiting efficiency of the different additives was evaluated from their anodic and cathodic polarization curves at different temperatures.A comparative study of curve fitting procedures using the kinetic thermodynamic model and those utilizing well‐known adsorption isotherms was undertaken. Three types of isotherms were used, Langmuir, Frumkin and Flory‐Huggins isotherm. The results show that the kinetic‐thermodynamic model and Flory‐Huggins isotherms are more suitable to fit the data for the four inhibitors, at all applied temperatures. From the values of binding constants, K, the order of inhibitor efficiency is:III > IV > II > Iand thus 2‐mercapto‐5‐methylbenzimidazole was the most effective inhibitor. The thermodynamic parameters obtained for all the compounds used showed low values of Hads, which indicates that the action of these inhibitors is physically adsorptive in nature.
Assessment and control of MIC in a sugar cane factory
Authors: Setareh M. , Javaherdashti R. 
Published: April 2003

AbstractMicrobiologically influenced corrosion (MIC) in a sugar cane factory was studied. Also, two types of industrially recommended biocides and a mixture of them were evaluated by using kill time method. The results showed that some countermeasures were necessary to be applied to lower the risk of MIC. The concentrations of the biocides used in this study revealed that the biocides, under the testing conditions, had no biocidal effect what so ever.
Röntgenkleinwinkeluntersuchungen an lösungen von β‐naphtholorange
Authors: Kratky Von O. , Ledwinka H. , Pilz I. 
Published: April 2003

AbstractNach der Absolutintensität der Röntgenkleinwinkelstreuung liegt der Farbstoff ß‐Naphtholorange in sehr verdünnter wäßriger Lösung monomolekular vor, und es tritt mit wachsender Konzentration eine schwache Assoziation auf. Bei Lösungen mit KCl‐Zusatz führt die Extrapolation auf die Konzentration null des Farbstoffs ebenfalls auf den monomolekularen Lösungszustand; dann nimmt aber mit waschsender Konzentration die Assoziation erheblich mehr zu. Die Zusammenlagerung erfolgt in den beiden Richtungen senkrecht zur größten Dimension des Moleküls, wodurch bei entsprechnd hohem Assoziationsgrad blättchenförmige Aggregate von der Dicke 13,5 Å entstehen, die dieser größten Dimension des Einzelmoleküls entspricht. Die Fläche der Blättchen wächst proportional dem Assoziationsgrad, und die Gesamtgestalten sind, wie Vergleiche mit theoretischen Streukurven zeigen, in ausreichender Näherung mit Parallelepipeden streuungsäquivalent. Die Aggregate sind außerordentlich locker gebaut; das Volumen, das in diesen ein Molekül einnimmt, ist etwa das Vierfache des partiellen spezifischen Volumens. Das Problem, wie die Bindung zustande kommt, bedarf eines weiteren Studiums.
Polymerization of propylene to syndiotactic polymer. IV. Addition to the double bond
Authors: Zambelli A. , Giongo M. G. , Natta G. 
Published: April 2003

AbstractBy the study of differently deuterated homopolymers and copolymers of propylene it is demonstrated that the double bond addition is cis in the syndiotactic polymerization of propylene. Furthermore it is confirmed that the addition to the double bond is cis also in the isotactic polymerization.
Study on the pyrolysis of cellulose and its derivatives
Authors: Patel K. S. , Patel K. C. , Patel R. D. 
Published: April 2003

AbstractKinetics of pyrolysis of cotton cellulose and cellulose acetate with different degrees of substitution have been studied. The range of decomposition temperature of the cellulose samples was found to decrease with the increase in degree of substitution. However, the stability of the polymer increased as the degree of substitution increased. Probable mechanism of degradation of the test samples is discussed. Energy of activation and order of reaction for the decomposition of polymer samples as well as for the residual materials have been determined and correlated with DTA measurements.
Alkali metal solutions in organic solvents obtained in the presence of polyethylene oxide
Authors: Panayotov I. M. , Tsvetanov Ch. B. , Berlinova I. V. , Velichkova R. S. 
Published: April 2003

AbstractAlkali metals dissolve not only in liquid ammonia but also in ethers, such as tetrahydrofuran (THF), 1.2‐dimethoxyethane (DME), and dimethyl ether of diethylene glycol (diglyme), blue solutions being obtained1,2. “Blue” solutions can be obtained only with rigorously purified reagents in full absence of moisture and oxygen, usually at low temperature. They are not very stable systems, especially at room temp., and discoloration begins shortly after the removal of the metal. The concn. of the metal dissolved is as low as 10‐4 to 10‐3 mole/1. The electrical conductivity of the “blue” solutions is in the range of 10‐5 to 10‐6 ohm‐1 cm‐1 and that of the discolored solution is 10‐8 to 10‐9 ohm‐1 cm‐1.Obviously the solvation ability of the solvent plays a very important role in the formation of metal solutions. DAINTON et al.1,3 presented arguments that the predominant species in the “blue” solutions are pairs of electrons (e2) with coupled spins, whereas TUTTLE and WEISSMAN4 observed at ‐80°C a weak singlet in the ESR spectrum of the potassium solution in DME, and CAFASSO and SUNDHEIM2 revealed a weak ESR signal in a rubidium solution in bis‐2‐(2‐methoxyethoxy) ethyl ether as well as in a frozen potassium solution in DME.“Blue” alkali metal solutions can be easily obtained in hexamethylphosphoramide but it is not still clear whether they are solutions of alkali metals5 or of anion‐radicals of the solvent6.It was established that potassium solutions in THF and DME initiated polymerization of acrylonitrile (conversion about 4%) and of styrene (conversion up to 100%), but not of methyl methacrylate and acrylamide3.
Catalyse de transformation des oléfines par les complexes du tungstène. II. Télomérisation des oléfines cycliques en présence d'oléfines acycliques
Authors: Jean‐Louis Hérisson Par , Chauvin Yves 
Published: April 2003

AbstractLa co‐réaction des oléfines cycliques avec les oléfines acycliques en présence des systèmes WOCl4/Al(C2H5)2Cl et WOCl4/Sn(C4H9)4 conduit à une télomérisation de l'oléfine cyclique; aux extrémités des molécules de télomère sont fixés deux groupements, identiques ou différents, issus de l'oléfine acyclique par une réaction non consécutive.Ont été plus particulièrement étudiés: le cyclopentène et le cyclooctène d'une part, le pentène‐2, le pentène‐1, le butène‐2 et le propylène d'autre part.Le cyclooctadiène‐1.5 et le cyclododécatriène‐1.5.9 réagissent avec le pentène‐2, par réaction non consécutive, en tant que reste CHCH2CH2CH.La répartition des télomères obéit à une loi statistique.On propose un schéma réactionnel en accord avec les faits observés dans la réaction de disproportion des oléfines acycliques, la polymérisation des oléfines cycliques et la télomérisation des oléfines cycliques par les oléfines acycliques.
KUHN‐MARK‐HOUWINK‐SAKURADA relations and unperturbed dimensions of poly(di‐n‐alkyl itaconates)
Authors: Veličković Jovan , Vasović Slavica 
Published: April 2003

AbstractKUHN‐MARK‐HOUWINK‐SAKURADA relations for poly(dimethyl‐, diethyl‐, di‐n‐propyl‐, di‐n‐butyl‐, di‐n‐hexyl‐, di‐n‐octyl‐, di‐n‐decyl‐, and di‐n‐undecyl itaconate) were established in toluene at 25°C. The decreasing exponent a from 0.80 to 0.61, in going from lower to higher members of the series, reflects the decreasing solvent power of toluene. Observed high molecular weights of the polymers are in disagreement with formerly assumed strong chain transfer to monomer in the propagation step. σ‐parameters, evaluated according to the KURATA‐STOCKMAYER extrapolation procedure, within limits of 1.98 and 3.50, indicate strong and progressively increasing steric hindrance to free rotation in this polymer homologueous series.
Reactivities of some organozinc initiators for copolymerization of carbon dioxide and propylene oxide
Authors: Inoue Shohei , Kobayashi Makoto , Koinuma Hideomi , Tsuruta Teiji 
Published: April 2003

AbstractCopolymerization of carbon dioxide (CO2) and propylene oxide (PO) was carried out by using diethylzinc/water and diethylzinc/methanol catalyst systems. A remarkable amount of polycarbonate was obtained using the former system, but hardly any polymer was formed with the latter catalyst. The difference between these two systems was examined in relation to the elementary processes of the copolymerization. Both the catalysts react with CO2 to produce XZnOCOOR, where X = OCH3 for the diethylzinc/methanol system and X = (OZn)nOH or (OZn)nC2H5 for the diethylzinc/water system. The reactivity of XZnOCOOR with PO depends on X and the difference between the two systems can be explained by the presence or absence of repeating ZnO bonds.Diethylzinc/primary amine systems produced copolymers while diethylzinc/secondary amine systems were inefficient yielding only small quantities of polymer. This can also be explained by the presence or absence of repeating ZnNR bonds.
Thermal degradation of isotactic and atactic poly(methyl vinyl ketones)
Authors: Matsuzaki Kei , Ohshima Shozo 
Published: April 2003

AbstractThe stereoregularity of poly(methyl vinyl ketone) (PMVK) was determined by NMR spectra of the polymers. Isotactic and atactic PMVK's were thermally degraded, and thermogravimetric analysis, IR and visible and UV spectroscopy were applied to elucidate the mechanism of the degradation. It was found that the isotactic polymer begins to degrade at lower temperature than the atactic polymer, but its rate becomes lower than that of the atactic polymer at temperatures higher than 320°C. If the two types of polymers were treated at a constant temperature (200°C) for varying times under N2 atmosphere, the isotactic polymer showed a higher degradation rate as determined by thermogravimetric analysis and IR spectroscopy. The isotactic polymer shows a higher tendency to form a monocyclic structure in the heat treatment than the atactic polymer. This is similar to poly(isopropenyl methyl ketone).