bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid–liquid equilibria of multicomponent lipid mixtures under CO2 pressure: Measurement and thermodynamic modeling
Authors: Vezzù K. , Bertucco A. , Lucien F. P. 
Published: July 2008

AbstractA method for evaluating solid–liquid equilibria of mixtures of lipids and carbon dioxide (CO2) under pressure is developed and presented in this article. Experimental measurements by high‐pressure differential scanning calorimetry (DSC) are performed to determine solid–liquid transition temperatures as a function of composition. These data are used to develop a simplified approach for thermodynamic modeling, that is, correlation and prediction, of the solid–liquid equilibria. The model requires fewer pure component properties in comparison with cubic equations of state: the solid‐state fugacity is determined with reference to the subcooled liquid state whereas regular solution theory is applied for the calculation of liquid‐phase activity coefficients. Application of the model is demonstrated for mixtures of ceramide 3A and cholesterol in compressed CO2 in the range of pressure from 0.1 to 6.1 MPa. A satisfactory correlation of solid–liquid equilibria is obtained for binary systems consisting of either the lipid mixture or one lipid in compressed CO2. With the fitted binary interactions parameters, the eutectic temperature of the ternary mixture is predicted to within 1°C of the experimental value in the range of pressure considered. The proposed evaluation method looks sufficiently accurate for representing multiphase equilibria of lipid mixtures in compressed CO2 and has direct application to gas‐assisted micronization processes such as PGSS (Particles from Gas‐Saturated Solution). © 2008 American Institute of Chemical Engineers AIChE J, 2008
Adsorption heterogeneity of lysozyme over functionalized mesoporous silica: Effect of interfacial noncovalent interactions
Authors: He Jing , Liu Zhijun , Hai Chunxi 
Published: July 2008

AbstractIn this work, the surface–protein interfacial noncovalent interactions are generated and tuned as hydrogen bonding, hydrophobic affinity, electrostatic interaction, and additional π‐π overlapping through designing suitable surface property with different chemical moieties and varying the pH of adsorption medium. The heterogeneity of lysozyme (Lz) adsorption is investigated. It has been found that the interfacial interactions of support surfaces and the protein play a key role in the adsorption kinetics, adsorption capacity, distribution states, and adsorption reversibility of Lz, while the protein–protein repulsion makes impact dependently on the nature of surface–protein interactions. The π‐π overlapping is another significantly crucial driving force in addition to the electrostatic force, hydrophobic interaction, and hydrogen bonding that commonly drive protein adsorption. But the hydrogen bonding between surface NH2 and Lz is exceptionally not sufficient to drive Lz adsorption. The adsorption of Lz on functionalized mesoporous silica is partial reversible and makes no damage on the protein secondary structure. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Morphometrics of wild black‐and‐white ruffed lemurs [Varecia variegata; Kerr, 1792]
Authors: Baden Andrea L. , Brenneman Rick A. , Louis Edward E. 
Published: July 2008

AbstractThis study presents the first detailed morphometric measurements of wild caught black‐and‐white ruffed lemurs (Varecia variegata) from the eastern rainforests of Madagascar and aims to quantify the morphological variation present throughout their recognized range. One hundred and forty‐four adult and juvenile individuals from 15 sites were sampled for 20 cranial, dental and postcranial morphometric and body mass measurements. Data were collected from an equal number of male and female individuals sampled across seasons over a 7‐year period (1999–2002, 2004–2006). Results indicate that adult body mass and morphometric measurements varied between sexes across sites; however, the only significant intersexual difference found was that females possessed, on average, longer tails than males. Contrary to previous studies, significant seasonal variation could not be detected in either male or female body mass or testicular volume (i.e., breeding vs. nonbreeding, food‐scarce vs. food‐abundant seasons). Measurements did, however, vary significantly by site and subspecies, though clinal variation could not explain these differences. The introduced population from Nosy Mangabe exhibited significantly lower body mass and overall body length than all other populations; however, this distinction may not have been attributable to natural variation, and may have instead resulted from the ecologically restrictive habitat (e.g., unusually high lemur population densities, limited food resources, ecological isolation) of this introduced population. Finally, although fore‐to‐hindlimb, brachium‐to‐thigh and hindlimb indices were comparable to previous values, forelimb indices calculated here deviate significantly from previous reports, placing V. variegata within the upper range of lemurid taxa. It is currently unknown whether this is an artifact of sampling methods (i.e., live vs. skeletal specimens) or whether this is an avenue that warrants further investigation. Am. J. Primatol. 70:913–926, 2008. © 2008 Wiley‐Liss, Inc.
Ecogeographic variation in human nasal passages
Authors: Yokley Todd R. 
Published: July 2008

AbstractTheoretically, individuals whose ancestors evolved in cold and/or dry climates should have greater nasal mucosal surface area relative to air volume of the nasal passages than individuals whose ancestors evolved in warm, humid climates. A high surface‐area‐to‐volume (SA/V) ratio allows relatively more air to come in contact with the mucosa and facilitates more efficient heat and moisture exchange during inspiration and expiration, which would be adaptive in a cold, dry environment. Conversely, a low SA/V ratio is not as efficient at recapturing heat and moisture during expiration and allows for better heat dissipation, which would be adaptive in a warm, humid environment. To test this hypothesis, cross‐sectional measurements of the nasal passages that reflect surface area and volume were collected from a sample of CT scans of patients of European and African ancestry. Results indicate that individuals of European descent do have higher SA/V ratios than individuals of African descent, but only when decongested. Otherwise, the two groups show little difference. This pattern of variation may be due to selection for different SA/V configurations during times of physical exertion, which has been shown to elicit decongestion. Relationships between linear measurements of the skeletal nasal aperture and cavity and cross‐sectional dimensions were also examined. Contrary to predictions, the nasal index, the ratio of nasal breadth to nasal height, is not strongly correlated with internal dimensions. However, differences between the nasal indices of the two groups are highly significant. These results may be indicative of different adaptive solutions to the same problem. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Rheological properties of cellulose/chitin xanthate blend solutions and properties of the prepared fibers
Authors: He Chunju , Sun Junfen , Ma Bomou , Wang Qingrui 
Published: July 2008

AbstractThe focus of this article is the rheological properties of cellulose xanthate, chitin xanthate, and their blend solutions with cellulose/chitin blend weight ratios of 9.5 : 0.5, 9 : 1, 8 : 2, and 5 : 5 (mostly 9 : 1 blend solutions). The preparation and properties of fibers from 9 : 1 blend solutions and cellulose xanthate solutions are also discussed. The non‐Newtonian index of the investigated solutions was found to vary in the following order: chitin < cellulose < 9.5 : 0.5 blend < 9 : 1 blend < 8 : 2 blend < 5 : 5 blend. Showing a tendency contrary to that of the non‐Newtonian index, the structure viscosity index varies in the following order: chitin > cellulose > 9.5 : 0.5 blend > 9 : 1 blend > 8 : 2 blend > 5 : 5 blend. For 5–9 wt % 9 : 1 blend solutions, increasing the solution temperature aids the improvement of the fluidity of 9 : 1 blend solutions in the temperature range of 10–40°C. The zero shear viscosity decreases in an index manner with the solution temperature increasing. The 7–8 wt % 9 : 1 blend solutions have good filtering and rheological properties and are ideal for spinning fibers. The mechanical properties of blend fibers spun from 7% 9 : 1 blend solutions are lower than those of pure cellulose and are much higher than those of Crabyon fiber, and they still reach the national criteria and fit the need for further processing. This proves that the viscose method which we have developed here is an efficient way of preparing cellulose/chitin blend fibers with satisfactory mechanical properties and processing properties. Scanning electron microscopy photographs show that the surface of 9 : 1 blend fibers is coarser than that of pure cellulose fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of sulfonated copolyimides containing aliphatic linkages as proton‐exchange membranes for fuel cell applications
Authors: Deligöz Hüseyin , Vantansever Sibel , Koç S. Naci , Öksüzömer Faruk , Özgümüş Saadet , Gürkaynak M. Ali 
Published: July 2008

AbstractA series of random sulfonated copolyimides containing aliphatic linkages (co‐SPIAs) with controlled degrees of sulfonic acid groups were synthesized via a conventional two‐step polyimidization method. 2,4‐Diaminobenzene sulfonic acid (2,4‐DABS) and 1,6‐diaminohexane (DAH) were used as sulfonated aromatic diamine and nonsulfonated aliphatic diamine compounds, respectively. Mixtures of diamine compounds were reacted with benzophenonetetracarboxylic dianhydride (BTDA) to obtain the co‐SPIAs. The molar ratios of DAH/2,4‐DABS were systematically varied to produce copolymers with controlled compositions that contained up to 70 mol % sulfonic acid moieties. The co‐SPIAs were evaluated for thermal oxidative stability, ion‐exchange capacity (IEC), water uptake, proton conductivity, solubility, and hydrolytic stability. The proton conductivity and hydrolytic stability of the co‐SPIAs were compared with the fully aromatic polyimide, sulfonated homo‐polyimide (homo‐SPI) (BTDA/2,4‐DABS). From thermogravimetric analysis, we observed desulfonation temperatures in the range 200–350°C, which suggested a high stability of the sulfonic acid groups. The co‐SPIAs with 40–70 mol % 2,4‐DABS showed higher proton conductivity than Nafion 117 in water. The proton conductivity values of the co‐SPIAs were mainly a function of IEC and water uptake. Furthermore, the hydrolytic stability of the 2,4‐DABS‐based sulfonated polyimide membranes were improved by the introduction of the nonsulfonated diamine with aliphatic linkages. The optimum concentration of 2,4‐DABS was found to be around 40 mol % from the viewpoint of proton conductivity, IEC, and hydrolytic stability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Durability of the wettability properties of a polypropylene film with a low‐pressure CH4–O2 plasma treatment
Authors: Garcia D. , Fenollar O. , Lopez R. , Sanchis R. , Balart R. 
Published: July 2008

AbstractThe aim of this work was to study the durability of a polypropylene film plasma‐treated with an 80 : 20 methane–oxygen gas mixture. Three different storage conditions were used to evaluate the influence of the relative humidity and temperature on the aging process. The surface functionalization of the polypropylene film was analyzed with X‐ray photoelectron spectroscopy and attenuated total reflectance/Fourier transform infrared spectroscopy analysis, and the variations of the surface energy and its polar and dispersive components were also investigated. The effects of this plasma treatment were similar to those of a plasma polymerization process, the ablation and polymerization mechanisms taking place simultaneously at the treated surface, but in this case, we obtained hydrophilic properties. The obtained results indicated an improvement of wettability and high durability of the plasma‐treated polypropylene film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Zinc lactate‐catalyzed ring‐opening polymerization of trimethylene carbonate under microwave irradiation
Authors: Zhang Chao , Liao Liqiong , Gong Shaoqin 
Published: July 2008

AbstractMicrowave‐assisted ring‐opening polymerization (MROP) of trimethylene carbonate (TMC) was carried out with four different types of zinc lactate, as the catalyst. Poly(trimethylene carbonate)s (PTMC) with a number–average molar mass ranging from 2990 to 75,410 g/mol and a TMC conversion ranging from 85.2% to 98.2% were synthesized effectively in 30 min at 120°C under microwave irradiation. The effects of the catalyst type, catalyst concentration, and microwave irradiation time on the MROP of TMC were studied. The MROP of TMC was much faster than that under conventional heating conditions. Thermal analysis suggested that PTMC with higher molar mass exhibited higher glass transition temperature (Tg) and thermal stability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Rheological properties of progesterone microemulsions: Influence of xanthan and chitosan biopolymer concentration
Authors: Corrias F. , Dolz M. , Herraez M. , Diez‐Sales O. 
Published: July 2008

AbstractIn this preformulations study, rheological properties of microemulsions with progesterone (1%) were studied to analyze the effect of xanthan and chitosan at different concentrations (0.5–3%). Steady shear and oscillatory rheological properties were analyzed using a controlled stress rheometer. Steady shear data were satisfactorily adjusted to the Carreau model. For all preparations, shear‐thinning behavior was observed. Zero shear viscosity (η0) increased with the biopolymer concentration. The results from dynamic experiments showed the behavior of all preparations with xanthan gum and those of chitosan to be characteristic of weak gels and liquid‐like solutions, respectively. The correlation between dynamic and steady‐shear properties (extended Cox‐Merz rule) was satisfactory for the two polymers. The recovery analysis of microemulsions with xanthan showed a total recovery percentage of 90% for the highest concentrations of this polymer. However, microemulsions with chitosan showed practically no recovery. Progesterone release was greater for the microemulsions with chitosan. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Nanocomposite particles with core‐shell morphology. I. Preparation and characterization of Fe3O4–poly(butyl acrylate‐styrene) particles via miniemulsion polymerization
Authors: Mahdavian Ali Reza , Ashjari Mohsen , Mobarakeh Hamid Salehi 
Published: July 2008

AbstractColloidal particles with magnetic properties have become increasingly important both technologically and for fundamental studies. Here, chemical initiator‐free miniemulsion polymerization of styrene and butyl acrylate has been performed for preparation of magnetic nanocomposite particles with the diameter of 81–150 nm in the presence of sodium dodecyl sulfate as surfactant, span 80 as stabilizer, and hexadecane as hydrophobe. The polymerization reaction was initiated and progressed under ultrasonic irradiation, generated by immersed probe into the latex. The key point in achievement of encapsulation of modified Fe3O4 nanoparticles was preparation of a stable colloidal dispersion at the end of the reaction. The obtained products in each step were characterized by FTIR spectroscopy. Dynamic light scattering analysis was used to follow particle size diameter of the samples. Morphology of the particles and formation of core‐shell structure were analyzed by SEM and TEM micrographs, respectively. TGA and magnetometry of the polymeric films confirmed the extent of insertion of used magnetite and their corresponding behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and Antimicrobial Evaluation of Some Novel 2‐Aminothiazole Derivatives of 4‐Hydroxy‐chromene‐2‐one
Authors: Vukovic Nenad , Sukdolak Slobodan , Solujic Slavica , Milosevic Tanja 
Published: July 2008

AbstractSyntheses of 2‐aminothiazole derivatives of 4‐hydroxy‐chromene‐2‐one 2c–10c are reported in this paper. These compounds 2c–10c were prepared from 3‐(2‐bromoacetyl)‐4‐hydroxy‐chromene‐2‐one 1 and corresponding thiourea derivatives 2b–10b using Hantzsch reaction. The structures of all compounds were confirmed by IR and 1H‐NMR spectroscopy and elemental analyses. The molecules 2c–10c were evaluated for in vitro antimicrobial activity against ten bacteria and twelve fungi. All tested compounds exhibited antibacterial and antifungal activity.
Perceptions and importance of user friendliness of IR systems according to users' individual characteristics and academic discipline
Authors: Vilar Polona , Žumer Maja 
Published: July 2008

AbstractThis article presents one part of a wider study, performed at the Department of library and information science and book studies (LIS & BS) at the University of Ljubljana (UL). The study investigated the perceptions of user friendliness of information‐retrieval systems (IRS) and the role of individual characteristics of users in these perceptions. Based on an expert study, a user study with 61 postgraduate students of the UL was performed. Three interfaces of e‐journals were studied: Science Direct, Proquest Direct, and Ebsco Host. Questionnaires and observations were used for data collection. The users'perceptions of user friendliness and of importance of auxiliary functions were investigated. Also, the connections between these perceptions and the users'individual characteristics were identified. Three sets of individual characteristics were included: approaches to studying, thinking styles, and hemisphere leanings. In connection with the dimensions of individual characteristics, very different perceptions of user friendliness were expressed. Some dimensions of individual characteristics were also found to be connected to the users'academic areas. It is shown that participants from different academic areas have different requirements and perceptions of user friendliness. The results of the study are relevant for the design of the user interfaces of disciplinary IR systems. They also have implications for other areas, for example, user education and training.
Pharmacokinetics of budesonide and formoterol administered via a series of single‐drug and combination inhalers: four open‐label, randomized, crossover studies in healthy adults
Authors: Eklund Annika , Tronde Ann , Johannes‐Hellberg Ingegerd , Gillen Michael , Borgström Lars 
Published: July 2008

AbstractObjective: To investigate the pharmacokinetics of budesonide and formoterol administered concomitantly in healthy adults.Methods: Three single‐dose, open‐label crossover studies (n=28 each) were conducted (Study I: budesonide pMDI, formoterol DPI, budesonide pMDI+formoterol DPI; Study II: budesonide/formoterol pMDI, budesonide pMDI+formoterol DPI; Study III: budesonide/formoterol pMDI [three budesonide formulation strengths; constant formoterol]). Study IV (n=28) assessed steady state pharmacokinetics (budesonide/formoterol pMDI [two/four inhalations twice daily, 5‐day treatment; four inhalations, single‐dose]).Results: Study I: no pharmacokinetic interactions were observed between budesonide and formoterol. Study II:AUCratios were 97.9% (budesonide) and 82.2% (formoterol) (budesonide/formoterol pMDI versus budesonide pMDI+formoterol DPI). Study III: formoterolAUCwas comparable across budesonide/formoterol pMDI formulation strengths; budesonideAUCincreased with formulation strength in proportion to fine particle dose. Study IV: dose proportionality was demonstrated for budesonide (AUCratio, 104.3%) and suggested for formoterol (AUCratio, 117.6%) with budesonide/formoterol pMDI (steady state); budesonide and formoterolAUCwas higher with repeated versus single‐dose budesonide/formoterol pMDI (four inhalations).Conclusions: No pharmacokinetic interactions were observed between budesonide and formoterol. Budesonide dose variation in budesonide/formoterol pMDI did not affect formoterol exposure. Steady state budesonide/formoterol pMDI dose‐doubling yielded proportional increases in budesonide and formoterol exposure. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of gender in the oral pharmacokinetics of clindamycin in humans
Authors: Carrasco‐Portugal Miriam del Carmen , Luján Miguel , Flores‐Murrieta Francisco Javier 
Published: July 2008

AbstractClindamycin is an antimicrobial agent metabolized by CYP3A4. Gender may influence the pharmacokinetics of drugs metabolized by this pathway, however, no information about differences in the pharmacokinetics of clindamycin in men and women is available. The purpose of this study was to evaluate gender differences in clindamycin oral pharmacokinetics. Twenty‐four subjects (11 men and 13 women) received an oral 600 mg dose of clindamycin under fasting conditions and plasma concentrations were obtained at selected times during 12 h. Increased plasma levels were observed in women, but when the dose was normalized by the body weight of individuals, these differences disappeared, indicating that gender does not play an important role in the pharmacokinetics of this drug. Copyright © 2008 John Wiley & Sons, Ltd.
Fungal sex genes—searching for the ancestors
Authors: Casselton Lorna A. 
Published: July 2008

AbstractThe sex‐determining genes of fungi reside at one or two specialised regions of the chromosome known as the mating type (MAT) loci. The genes are sufficient to determine haploid cell identity, enable compatible mating partners to attract each other, and prepare cells for sexual reproduction after fertilisation. How conserved are these genes in different fungal groups? New work1 seeks an answer to this question by identifying the sex‐determining regions of an early diverged fungus. These regions bear remarkable similarity to those described in other fungi, but the sex proteins they encode belong to only a single class of transcription factor, the high mobility group (HMG), indicating that these are likely to be ancestral to other proteins recruited for fungal sex. BioEssays 30:711–714, 2008. © 2008 Wiley Periodicals, Inc.
The core endodermal gene network of vertebrates: combining developmental precision with evolutionary flexibility
Authors: Woodland Hugh R. , Zorn Aaron M. 
Published: July 2008

AbstractEmbryonic development combines paradoxical properties: it has great precision, it is usually conducted at breakneck speed and it is flexible on relatively short evolutionary time scales, particularly at early stages. While these features appear mutually exclusive, we consider how they may be reconciled by the properties of key early regulatory networks. We illustrate these ideas with the network that controls development of endoderm progenitors. We argue that this network enables precision because of its intrinsic stability, self propagation and dependence on signalling. The network enables high developmental speed because it is rapidly established by maternal inputs at multiple points. In turn these properties confer flexibility on an evolutionary time scale because they can be initiated in many ways, while buffering essential progenitor cell populations against changes in their embryonic environment on both evolutionary and developmental time scales. Although stable, these networks must be capable of rapid dissolution as cell differentiation progresses. While we focus on the core early endodermal network of vertebrates, we argue that these properties are likely to be general in early embryonic stem cell populations, such as mammalian ES cells. BioEssays 30:757–765, 2008. © 2008 Wiley Periodicals, Inc.