bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypericin uptake in rabbits and nude mice transplanted with human squamous cell carcinomas: Study of a new sensitizer for laser phototherapy
Authors: Chung Phil‐Sang , Rhee Chung‐Ku , Saxton Romaine E. , Castro Dan J. , Paiva Marcos B. , Soudant Jacques , Mathey Annick , Foote Christopher 
Published: November 2006

AbstractTissue uptake and biodistribution of hypericin was measured in rabbits and in nu/nu mice xenografted with P3 human squamous cell carcinoma to assess the value of this dye as an in vivo sensitizer for laser photoinactivation of solid tumors. Hypericin has absorption maxima at 545 and 590 nm with a fluorescence emission peak at 640 nm in ethanol. Dye uptake after intravenous injection was tested at 4 and 24 hours in rabbit tissues by ethanol extraction and quantitative fluorescence spectrophotometry. Maximum dye levels were seen at 4 hours in most vascular organs with lung having fivefold higher uptake than spleen followed by liver, blood, and kidney. Mice were examined after 2, 4, 6, 8, and 24 hours and after 3 and 7 days for dye uptake. The peak concentration of hypericin in murine organs was reached at 4 hours with uptake per gram of tissue as follows: lung>spleen>liver>blood>kidney>heart>gut>tumor>stomach>skin>muscle>brain. Elimination of hypericin was rapid in most murine organs with residual dye under 10% of maximum by 7 days compared to 25% to 30% retention for the squamous cell tumors and several normal tissues. These results suggest that hypericin may be a useful photosensitizer for KTP/532 laser interstitial therapy of human cancer.
Mucociliary activity and ultrastructural abnormalities of regenerated sinus mucosa in rabbits
Authors: Min Yang‐Gi , Kim Ic‐Tae , Park Sang‐Hoo 
Published: November 2006

AbstractThe purpose of this study was to observe histologic findings in the regenerated maxillary sinus mucosa and restoration of ciliary activity by measuring the speed of mucociliary transport after complete surgical removal of the maxillary sinus mucosa. The maxillary sinuses of 32 rabbits were opened anteriorly and one side of the sinus mucosa of each animal was completely removed. In 16 animals, the natural ostia were widened, and, in another 16 animals, the natural ostia were left undisturbed. The contralateral, sham‐operated sinus was used as a control for each animal.The animals of each group were reanesthetized and the maxillary sinuses were reopened at planned intervals. The speed of mucociliary transport toward the maxillary ostium, determined by India ink particle movement, was reduced to 6.4 mm/min, whereas it was 10.8 mm/min in the control side. Beating cilia were observed in 16% by dark‐field microscopy, in contrast to 66% in the control sinus. Pseudostratified columnar epithelia without cilia were present in 12%, with the remaining consisting of pseudostratified ciliated columnar epithelia (88%). Light microscopic examination showed increase in submucosal fibrotic proliferation, decrease in submucosal glands, and infiltration of inflammatory cells. Under transmission electron microscopy, abnormal cilia such as compound cilia or edematous cilia were frequently found in the regenerated specimens. These observations suggest that mucociliary clearance of the regenerated sinus mucosa may be significantly diminished compared with that of the original mucosa.
Total conservative parotidectomy for primary benign pleomorphic adenoma of the parotid gland: A 25‐year experience with 229 patients
Authors: Laccourreye Henri , Laccourreye Ollivier , Cauchois Régis , Jouffre Véronique , Ménard Madeleine , Brasnu Daniel 
Published: November 2006

AbstractA 25‐year experience with total conservative parotidectomy for primary benign pleomorphic adenoma (PBPA) of the parotid gland in a consecutive series of 229 patients has been reviewed. This study focuses on survival, morbidity, PBPA recurrence, postoperative facial nerve dysfunction, and Frey's syndrome. Surgical death was never encountered in this study. The overall incidence for postoperative hemorrhage, hematoma, seroma, skin necrosis, great auricular nerve schwannoma, and keloid scar was 1.7%, 6.1%, 4.8%, 0.9%, 15.7%, and 8.3%, respectively. Five‐, 10‐, 15‐, and 20‐year PBPA control actuarial rate was 99.6%. The overall incidence for temporary facial paresis and paralysis was 64.6% and 5.6%, respectively. Kaplan‐Meier actuarial analysis demonstrated that paresis recovery was noted until the eighteenth postoperative month. The overall incidence for permanent facial paresis and paralysis was 3.9% and 0%, respectively. None of the following variables—sex, age, PBPA size, PBPA location, PBPA contact with the facial nerve, inadvertent PBPA spillage, or surgeon's experience— was statistically related to PBPA recurrence and facial nerve dysfunction. The overall incidence for Frey's syndrome was 65.9%. Kaplan‐Meier actuarial analysis demonstrated the need for a minimal 5‐year follow‐up to assess Frey's syndrome incidence. The mean age was statistically lower in patients presenting with Frey's syndrome.
Optical data storage in LC cells
Authors: Sutkowski M. , Grudniewski T. , Zmijan R. , Parka J. , Nowinowski-Kruszelnicki E. 
Published: November 2006

AbstractLiquid crystal devices as a medium for holograms storage have been investigated. Long term memory effects in LC cells have been observed. Experiments proved that certain combination of insulating alignment layers has a major influence on the long term memory effect. Optimal liquid crystal cell construction allows us to achieve sufficient diffraction efficiency to record holographic patterns and to develop a re-writable holographic medium. The configuration of PVK and polyimide layers in LC cell construction with specific LC mixture was tested. The method of permanent and re-writable recording of optical data (holographic pattern) onto LC cells was achieved. However, the method of erasing recorded data was realized but mechanisms of this phenomenon are not clearly understood yet.
Hydrotropic and surfactant properties of novel diisopropyl naphthalene sulfonates
Authors: Burns Robert L. , Duliba Edward P. 
Published: November 2006

AbstractA novel surfactant and hydrotrope, sodium diisopropylnaphthalene sulfonate (SDIPNS) has been developed. It contains about 92% diisopropylnaphthalene sulfonate, compared to other materials which are less than 50% diisopropylnaphthalene sulfonate. Aqueous solutions of 34–36% active SDIPNS have dual functionality. They have excellent surface properties and are compatible with conventional anionic, nonionic, and amphoteric surfactants. They demonstrate good laundering detergency in combination with sodium lauryl ethoxy sulfate, with or without builder. They maintain surface activity in 150 ppm hard water (Ca2+/Mg2+=2∶1), 5% NaCl, pH 2, and pH 12. They are effective hydrotropes. They enhance surfactant solubility, raise the cloud point of nonionic surfactants, and modify the viscosity of surfactant formulations. They are light in color and are low‐foaming.
Nonionic cleavable ortho ester surfactants
Authors: Hellberg Per‐Erik , Bergström Karin , Juberg Malin 
Published: November 2006

AbstractA new class of cleavable surfactants based on the ortho ester link is described. Ortho ester surfactants were synthesized from a short‐chain ortho ester, a fatty alcohol, and a poly(ethylene glycol) monomethyl ether. The triple functionality of the ortho ester link results in a mixture of surface‐active and nonsurface‐active species. Structures were confirmed by 1H and 13C nuclear magnetic resonance. Hydrolysis characteristics at pH values ranging from 2 to 8 were determined. It was shown that, after a steep rise, hydrolysis curves flattened out before complete hydrolysis was reached. Ortho ester surfactants hydrolyze more rapidly than corresponding acetal surfactants. Hydrolysis rates are higher for purified samples and at higher temeprature, while plateau levels are higher for the purified surfactant mixtures and at lower pH. The origin of these results is discussed. Data also indicate that the hydrolysis mechanism changes with pH. A test of the loss of emulsification capacity for an ortho ester surfactant with time at pH values from 2 to 11.5 and at 22 or 50°C was carried out, showing rapid breaking of the emulsion at mild acid conditions and a requirement of pH≥10 for long‐term stability. Surface tension and critical micelle concentration were determined for some of the surfactant mixtures. It was demonstrated that ortho ester surfactants possess excellent biodegradation properties. The new surfactants are promising candidates for use in industrial processes where temporary surfactant action is required.
Optimization of the enzymatic esterification of diglycerol and lauric acid
Authors: García Eva , Ferrari Flavio , García Tomás , Martínez Mercedes , Aracil José 
Published: November 2006

AbstractIn recent years, a number of industrial applications for lipases in biotransformation of fatty acids and lipids have been developed. One of the main reasons for this growing interest is the reduced overall catalyst cost owing to the development of commercially available immobilized enzymes, using polymeric carriers that facilitate recovery and reuse of the catalyst. Additional benefits for industrial applications include the specificity of the enzyme and the mild processing conditions. Diglycerol resulting from the dimerization of glycerol may replace molecules such as propylene glycol as the hydrophilic moiety of surfactants. Also, diglycerol fatty acid esters are useful as biodegradable nonionic surfactants for food, cosmetics, and pharmaceuticals. In this study, the enzymatic esterification of diglycerol and lauric acid has been optimized in a solvent‐free system. The reaction was carried out in a stirred batch reactor with a vacuum pump in order to shift the equilibrium toward the products. The commercial lipase Novozym‐435 was chosen as the most suitable catalyst, and the initial acid/alcohol ratio was always 1∶1. The reaction of lauric acid and diglycerol leveled off at equilibrium conversion after approximately 1 h of reaction. Previous work indicated that only temperature and catalyst concentration had significant effects on the conversion, and a full two‐factorial design has proved effective in the study of the influence of these two variables on the process. The temperature range studied was 63–77°C, and the range of the catalyst concentration was 0.2–5.8 wt%. Both catalyst concentration and temperature were found to be significant factors in the esterification process, and their influences are positive. The effect of the interaction between temperature and catalyst concentration was small. A first‐order approach could not fit the data adequately, and a model that included quadratic effects was required. A second‐order model was developed to predict the yield of ester as a function of the variables. Analysis of residuals showed that the model predicted accurately the acid conversion over the experimental range considered. This model is useful to determine the optimal operating conditions for the industrial process.
Relative rates of sulfonation of linear and branched long‐chain alkylbenzenes
Authors: Ward Robert S. , Diaper Richard L. , Roberts David W. 
Published: November 2006

AbstractRelative rates of sulfonation of a series of 1‐phenylalkanes and isomeric branched‐chain alkylbenzenes by gaseous SO3 have been determined. It has been shown that the composition of the mixture undergoing sulfonation has an important bearing on the actual relative rate constant (krel) values obtained. This is taken as evidence for the involvement of pyrosulfonic acids as the actual sulfonating species involved in the sulfonation reaction. Consistent krel values have been obtained by using an “active solvent” in 10‐fold excess as the sulfonating medium. Whereas the branched‐chain isomers show very little variation in their rates of sulfonation, the rates of sulfonation of the 1‐phenylalkanes increase as the length of the alkyl chain decreases.
Determination of critical micelle concentration (CMC) of nonionic surfactants by donor‐acceptor interaction with lodine and correlation of CMC with hydrophile‐lipophile balance and other parameters of the surfactants
Authors: Hait Samik Kumar , Moulik Satya Priya 
Published: November 2006

AbstractThe nonionic surfactants form donor‐acceptor complexes with iodine in aqueous medium. The spectral absorption and the shift in the λmax of l2 upon complexation have been exploited to determine the critical micelle concentration (CMC) of Tweens, Brijs, and Triton X‐100. The CMC values obtained closely agree with those determined by other methods, including measurements of static surface tension, differential refractive index, and iodine solubilization. The spectral characteristics of the complex salt Kl3 can be utilized as well to derive similar information. The CMC and the spectral shift can be correlated with the weight fraction of the polyoxyethylene groups and the hydrophile‐lipophile balance (HLB) in various ways, with the parameters in these relationships depending on the series to which the surfactant belong. Because both CMC and HLB depend on temperature, the results and the relations obtained are temperature‐dependent; those presented are with reference to 298 K.
Differences between alkyl polyglucosides of natural alcohol and oxo‐alcohol
Authors: Zhang Jian , Xie Ke‐chang , Dai Xi‐hai , Zhang Gao‐yong 
Published: November 2006

AbstractThis paper describes the differences between alkyl polyglucosides (APG) of natural alcohol and oxo‐alcohol. The same reaction rate was observed for the one‐step synthesis of APG from branched alcohols and from linear alcohols. Biodegradation studies showed that the primary biodegradability value of natural C8–10APG was slightly higher than for oxo‐C10–11APG, and there was no significant difference between oxo‐C12–13APG and C12–14APG. The primary biodegradability value of oxo‐C14–15APG was lower than the four APG already named. The goal of this study of the physicochemical properties of these APG of natural alcohol and oxo‐alcohol was to evaluate their differences. Diversification of APG selection will help improve its physicochemical properties and expand its application fields. The results are that the wetting abilities of oxo‐C10–11APG and oxo‐C12–13APG are better than the natural alcohol C8–10APG and C12–14APG, whereas the foamabilities of oxo‐C10–11APG and oxo‐C12–13APG are worse than those for natural C8–10APG and C12–14APG. There are no real differences in surface tension and detergency between APG of natural alcohol and oxo‐alcohol.
Synergism in mixed monolayers of alkylpolyglucoside and alkylsorbitan surfactants at liquid/liquid interface
Authors: Cinteza Otilia , Dudau Manuela 
Published: November 2006

AbstractA study of nonideal behavior in the formation of mixed monolayers at the oil‐water interface was performed for a nonionic‐nonionic surfactant system. Mixtures containing alkylpolyglucoside and alkylsorbitan derivatives were investigated. As the oily phase, colza‐rapeseed and olive oils were used. To evidence a synergetic effect in the interfacial tension reduction in the oil‐water‐surfactant‐cosurfactant system, the model based on the regular solution theory was modified for the case of both surfactants being soluble in the water as well as in the oily phase. For determination of the condition for the synergism and the point of the maximum synergetic effect, the molar fraction in the mixed monolayer Xs and the interaction parameter βs were calculated, using experimental data for the interfacial tension and for the partition coefficient. A set of general equations was developed, to allow the analysis of a mixture containing a water‐soluble and an oil‐soluble surfactant. The equations are applied according the characteristics of studied quaternary systems. The mathematical model was tested with literature data, and the results were compared with those obtained from the phase diagram of oil‐water‐mixed surfactant system. The systems water‐vegetable oil‐alkylpolyglucoside‐alkylsorbitan show a maximum synergetic effect at molar fractions between 0.85 and 0.90. The liquid‐liquid interfacial tension and partition coefficient data were used to calculate the point of the maximum synergetic effect, i.e., the surfactant‐cosurfactant ratio, which ensures the interfacial tension miniumum. The dramatic reduction in interfacial tension due to the presence of the surfactant mixture at the interface at the point of the synergism maximum is related to the formation of three‐phase and single‐phase microemulsions. The results were applied to obtain single‐phase microemulsion in water‐vegetable oil‐alkylpolyglucoside‐alkylsorbitan systems.
Hydrolysis and biodegradation studies of surface‐active esters
Authors: Stjerndahl Maria , van Ginkel Cornelis G. , Holmberg Krister 
Published: November 2006

AbstractBase‐catalyzed hydrolysis, biodegradation, and enzyme‐catalyzed hydrolysis of a series of four monoesters of tetra(ethylene glycol) have been investigated. The surfactants varied in substitution on the α‐carbon of the acyl chain, from no substitution, to 2‐methyl, to 2‐ethyl, and on to 2,2‐dimethyl. All surfactants were based on C8‐acids except the methyl‐substituted, which was based on a C7‐acid. The hydrolysis was investigated using 1H nuclear magnetic resonance. The surfactants showed a pronounced difference in stability with respect to type of substitution in the vicinity of the ester bond. In alka‐line hydrolysis the most significant difference in reactivity lay between the surfactant with an ethyl group and the surfactant with a methyl group in the α‐position of the acyl chain. However, in the biodegradation studies these surfactants broke down at almost exactly the same rate as the nonsubstituted surfactant. In the biodegradation test, the disubstituted surfactant deviated considerably. Two lipases, from Mucor miehei (MML) and Candida antarctica B (CALB), were used in the enzyme‐catalyzed hydrolysis. The surfactant with no substitution was found to hydrolyze much faster than the other surfactants, and the hydrolytic activity of MML, but not CALB, increased in the presence of surfactant micelles.
Mechanism of antifoam behavior of solutions of nonionic surfactants above the cloud point
Authors: Chaisalee Ratchadaporn , Soontravanich Sukkhwan , Yanumet Nantaya , Scamehorn John F. 
Published: November 2006

AbstractAqueous solutions of nonionic surfactants exhibit low foaming above their cloud point, a temperature above which the homogeneous solutions separates into two phases: a dilute phase containing a low surfactant concentration and coacervate phase containing a very high surfactant concentration (e.g., 20 wt% surfactant). In this work, foam formation was measured for the dilute phase, the coacervate, and the mixed solution using the Ross‐Miles method for nonylphenol polyethoxylates with 8, 9, or 10 ethylene oxide moieties per molecule. The dilute phase showed no antifoam effect above the cloud point if the coacervate phase was not present, and the coacervate phase foamed little in the absence of the dilute phase. The coacervate phase acts as an oil droplet antifoam to the dilute phase. From surface and interfacial tension data, entering, spreading, and bridging coefficients for this system make it appear probable that the coacervate phase is forming bridges across the film lamellae of the dilute‐phase foam and acting to suppress foam formation through the bridging mechanism.
Aggregation properties of amphiphilic poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) block copolymer studied by cyclic voltammetry
Authors: Ding Yuanhua , Wang Ying , Guo Rong 
Published: November 2006

AbstractThe cyclic voltammetric behaviors at a platinum electrode of an amphiphilic block copolymer [poly(ethylene oxide)‐block‐poly(propylene oxide)‐block‐poly(ethylene oxide) (F127)] in aqueous solutions were investigated. The mechanism of the electrochemical reaction of F127 at a platinum electrode was deduced. The diffusion coefficients of different‐shaped aggregates formed by F127 were determined on this basis. The first and second critical micelle concentrations, corresponding to the formation of spherical micelles and the transition of the spherical to rod‐like micelles, were 3.72×10−4 mol·L−1 and 1.49×10−3 mol·L−1, respectively, which could be confirmed by the fluorescent anisotropy of pyrene in the F127 aggregates and the morphology of F127 micelles observed by freeze‐fracture transmission electron microscopy.
Effect of temperature on the biodegradation of linear alkylbenzene sulfonate and alcohol ethoxylate
Authors: Prats Daniel , López Carmen , Vallejo Diana , Varó Pedro , León Víctor M. 
Published: November 2006

AbstractThe effect of temperature on the biodegradation of linear alkylbenzene sulfonate (LAS) and alcohol ethoxylate (AE) was evaluated using method OECD 303 A, Confirmatory test (Husmann units). The experiments were performed using an initial surfactant concentration of 10 mg/L and working temperatures of 25, 15, and 9°C, keeping the biodegradation units inside a thermostatic chamber. In all cases, the removal of both surfactants tested, LAS and AE, was higher than 90%, regardless of the temperature used in the test. We observed that longer acclimation periods were needed by the microorganisms at lower temperatures.
Comparison of the effects of dietary α‐linolenic, stearidonic, and eicosapentaenoic acids on production of inflammatory mediators in mice
Authors: Ishihara Kenji , Komatsu Wataru , Saito Hiroaki , Shinohara Kazuki 
Published: November 2006

AbstractThe effects of dietary stearidonic acid (18∶4n−3) on inflammatory mediator release in whole blood and splenocytes was investigated in Balb/c mice, and the effects were compared with those of two other n−3 PUFA: α‐linolenic acid (18∶3n−3) and EPA (20∶5n−3). TAG mixtures containing 10% of 18∶4n−3, 18∶3n−3, or 20∶5n−3 as the respective sole n−3 PUFA were enzymatically synthesized. Diets containing synthesized TAG mixtures were fed to Balb/c mice for 3 wk. The release of prostaglandin E2 (PGE2) and tumor necrosis factor (TNF) were measured in whole blood and splenocytes stimulated with lipopolysaccharide. In whole blood, the production of INF was suppressed by all dietary n−3 PUFA (18∶3n−3, 18∶4n−3, and 20∶5n−3) as compared with the control diet, which contained TAG prepared from safflower oil. PGE2 production was not significantly changed. Differences among the n−3 PUFA (18∶3n−3), 18∶4n−3, and 20∶5n−3) were not observed. In splenocytes, PGE2 production was suppressed by dietary n−3 PUFA, but TNF production was not. GC analysis of plasma and splenocyte FA profiles showed an increase in the levels of 20∶4n−3, 20∶5n−3, and 22∶6n−3 in mice fed the diet containing 18∶4n−3.
Synthesis of the conjugated trienes 5E,7E,9E,14Z,17Z‐eicosapentaenoic acid and 5Z,7E,9E,14Z,17Z‐eicosapentaenoic acid, and their induction of apoptosis in DLD‐1 colorectal adenocarcinoma cells
Authors: Tsuzuki Tsuyoshi , Tanaka Kazumi , Kuwahara Shigefumi , Miyazawa Teruo 
Published: November 2006

AbstractDuring the course of our recent study on the antitumor effect of conjugated eicosapentaenoic acids (CEPA), we found that acid mixtures prepared by treating EPA with KOH in ethylene glycol induced potent apoptotic cell death in human tumor cells via membrane phospholipid peroxidation. Interestingly, the KOH‐treated CEPA mixtures were more cytotoxic than EPA and CLA and had no effect on normal human fibroblast cells. To identify the specific cytotoxic FA in the CEPA mixture, we synthesized possible candidates for the active species. Here, we report the synthesis of (5E,7E,9E,14Z,17Z)‐5,7,9,14,17‐eicosapentaenoic acid (E‐CEPA) and its 5‐(Z) isomer (Z‐CEPA), both of which are conjugated trienes that exist naturally in red algae (Ptilota filicina J. Agardh). E‐CEPA and Z‐CEPA were synthesized from methyl 5‐oxopentanoate in six steps, using three types of Wittig reactions as the key steps. Next, we examined the cytotoxicity of E‐CEPA and Z‐CEPA in human tumor cells and confirmed their bioactivity. Both E‐CEPA and Z‐CEPA had a strong cytotoxic reaction in tumor cells, and this effect occurred through induction of apoptosis.