bluuebunny/crossref_metadata_2025 huggingface dataset:
Desiccants
Authors: Cohen Alan P.
Published: July 2004

Desiccants are classified by four drying mechanim: chemical reaction, physical absorption with constant relative humidity, physical absorption with variable relative humidity, and physical adsorption. Desiccants are further categorized by their use in static or dynamic drying applications. Various desiccants are discussed. Testing the compatibility of desiccants with the material being dried is briefly covered. The water capacity of some static desiccants and the efficiency (or effectiveness) of various desiccants in drying air and laboratory solvents are discussed. The dynamics of closed‐system drying is covered in some detail.

Desiccants used in dynamic applications include both liquids (sulfuric acid, glycols) and solids (activated alumina, silica gel, molecular sieves). Solid adsorbent drying systems with multiple beds are described. The use of adsorption equilibrium plots and the influence of desiccant properties on mass transfer and useful dryer capacity is covered. The factors affecting cost‐effectiveness of desiccants are discussed, and some market data are given for solid adsorbent desiccants. Finally, the emerging uses of desiccants for energy storage and cooling are mentioned.
Fluorine Compounds, Inorganic, Fluoroboric Acid and Fluoroborates
Authors: Papcun John R.
Published: July 2004

Fluoroboric acid and the fluoroborates are commercially important to a variety of industries. The acid is used in plating circuits, in metal finishing, in the production of aluminum, and as an acid catalyst. Main group metal and ammonium fluoroborates find use as fluxes, as catalysts, and in flame‐retardant manufacture. Transition‐ and other heavy‐metal fluoroborate salts are used in the plating industry and as catalysts. Properties and manufacture are described.
Fluorine Compounds, Inorganic, Germanium
Authors: Mahmood Tariq , Lindahl Charles B.
Published: July 2004

Germanium forms both a difluoride and a tetrafluoride as well as stable trifluorogermanite and hexafluorogermanite ions. Germanium difluoride is a white solid with mp 110C. It can be prepared by the reduction of GeF4by metallic Ge and by the reaction of stoichiometric amounts of Ge and HF. Germanium tetrafluoride is a gas that fumes strongly in air. It can be prepared by the thermal decomposition of BaGeF6or direct fluorination of Ge. GeF4is used in ion implantation to make semiconductor chips. It also acts as a Lewis acid to form complexes with many donor molecules.
Tetrachloroethylene
Authors: Hickman J. C.
Published: July 2004

Tetrachloroethylene [127‐18‐4], perchloroethylene, tetrachloroethene, CCl
2
+
= CCl
2
, commonly referred to as “perc,” is widely used in the dry‐cleaning industry as well as metal cleaning and vapor degreasing because of its excellent solvent properties. It has no flash point or flammable limits in air or oxygen. It is currently used as the feedstock in the production of CFC 113 (trichlorotrifluoroethane), but this end use will decline as CFC production is phased out under the Montreal Protocol. Demand for tetrachloroethylene was reported to be 610 thousand metric tons in 1987 worldwide. This article includes the physical and chemical properties of tetrachloroethylene, historical production and sales data within the United States, manufacturing locations and processes, as well as typical quality specifications. In addition, safety and toxicological considerations and environmental regulations pertinent to tetrachloroethylene are reviewed.
Trichloroethylene
Authors: Mertens James A.
Published: July 2004

Trichloroethylene, commonly referred to as “tri”, is a widely used vapor‐degreasing solvent. In recent years its popularity has fallen in favor of 1,1,1‐trichloroethane, mostly because of environmental restrictions on its use. Trichloroethylene has excellent solvency properties for a large number of natural and synthetic substances. This article includes physical and chemical properties, production, and use information. In addition, safety, toxicological, and environmental regulations pertinent to trichloroethylene are reviewed.
Pervaporation and vacuum membrane distillation processes: Modeling and experiments
Authors: Khayet Mohamed , Matsuura Takeshi
Published: July 2004

Two separation processes, pervaporation (PV) and vacuum membrane distillation (VMD), were studied using polyvinylidene fluoride (PVDF) flat‐sheet membranes for the separation of chloroform–water mixtures. Both PV and VMD membranes were prepared using the phase‐inversion method and the same polymer material. VMD membranes with different pore sizes were prepared using pure water as a pore‐forming additive in the PVDF/dimethylacetamide casting solution, whereas PV membranes were obtained with higher polymer concentration, without nonsolvent additives and with solvent evaporation before gelation. The mean pore size, porosity, and pore size distributions of the VMD membranes were determined. Water and formamide advancing and receding contact angles of PV membranes were measured. The swelling degree, the solubility parameter of PV membranes, and the interaction of the permeants with the PVDF polymer were calculated. In the VMD process, a more general theoretical model that considers the pore size distribution, the solution–diffusion contribution through nonporous membrane portion, and the gas transport mechanisms through membrane pores was developed based on the kinetic theory of gases. The contribution of each mechanism was analyzed. A comparative study was made between both membrane separation technologies. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1697–1712, 2004
Reconstructing relationships among mortality, status, and gender at the Medieval Gilbertine Priory of St. Andrew, Fishergate, York
Authors: Sullivan Amy
Published: July 2004

The varied relationships among status, gender, and mortality are complex, historically produced phenomena that shape people's lives and deaths in socially meaningful ways. Paleodemographic analysis coupled with acute sensitivity to site‐specific context has the potential to move us toward a greater understanding of these experiences in the past. After considering the potential effects of migration and fertility on the age‐at‐death profiles of adult individuals interred at the Gilbertine Priory of St. Andrew, Fishergate, York (n = 200), it is asserted that these profiles primarily reveal expected and unexpected relationships among status, gender, and mortality in this Medieval context. Collectively, the long lives of religious‐status males compared to other composite and gendered status groups suggest that they experienced a relatively comfortable existence despite periodic complaints of destitution. The postulated demographic advantage of high‐status males did not materialize in the analysis, and a reevaluation of the skeletal evidence indicates that nearly 20% of these individuals died violently. Unexpectedly, moderate‐status females shared a mortality profile similar to that of religious‐status males and retained a demographic advantage over all other secular status groups. In contrast to the experiences of moderate‐status females, low‐status females had, on average, the shortest lives at St. Andrew's. This pattern is intimately linked to their restriction from crucial social and economic resources, and provides further evidence of their marginalization in York's wage‐labor economy. Overall, these relationships suggest that traditional, highly stratified and gendered notions of Medieval status and mortality are not adequate for understanding the intricacies of everyday life and death at St. Andrew's. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Population genetics of apolipoproteins A‐IV, E, and H, and the angiotensin converting enzyme (ACE): Associations with lipids, and apolipoprotein levels in American Samoans
Authors: Crews Douglas E. , Fitton Lori J. , Kottke Bruce A. , Kamboh M. Ilyas
Published: July 2004

Distributions of alleles at three apolipoprotein loci (APO E, APO H, and APO A‐IV) and an insertion/deletion (I/D) polymorphism at the angiotensin converting enzyme (ACE) locus among 274 American Samoans are described here. Genotypes at each locus are examined for associations with quantitative lipid (total cholesterol (total‐c), LDL‐cholesterol (LDL‐c), HDL‐cholesterol (HDL‐c), and triglycerides) and apolipoprotein (APO AI, APO AII, APO E, and APO B) levels. Genotype frequencies at all four loci are in Hardy‐Weinberg equilibrium. The most common APO A‐IV genotype (1‐1) was observed in 252 American Samoans (97%). The three most common APO E genotypes were 3‐3 (47%), 3‐4 (30%), and 2‐3 (12%). The most frequent APO H genotype was 2‐2 (86%). The most common ACE genotype (I/I) was observed in 75% of sampled individuals, and 23% were I/D heterozygotes. APO E genotypic variation was associated with total‐c, HDL‐c, LDL‐c, and all four quantitative apolipoproteins (AI, AII, E, and B). APO A‐IV genotypes were associated significantly with total cholesterol, LDL‐c, and APO‐B levels. APO H showed little association with any quantitative lipid or apolipoprotein. ACE D/D homozygotes had higher AII levels. ACE showed a consistent association with APO AII levels, with either APO A‐IV or APO E as a covariate. The interaction term between ACE and APO E was also significantly associated with total‐c and APO E levels, and the ACE genotype showed a significant main effect on APO AI levels in multivariate analyses. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Relationship of strain magnitude to morphological variation in the primate skull
Authors: Daegling David J.
Published: July 2004

In a comparative study of variation in primate skulls, Wood and Lieberman ([2001] Am. J. Phys. Anthropol. 116:13–25) proposed that a predictable relationship exists between in vivo bone‐strain magnitudes and the extent of morphological variation in skeletal structures. They hypothesized that regions subject to high strains are prone to enhanced levels of variation. Three questions are posed with respect to the plausibility of this hypothesis. First, does the proposed relationship hold at different levels of analysis (e.g., for more restricted anatomical regions in which large strain gradients are present)? Second, is the biomechanical rationale for the hypothesis sound, given the current understanding of bone biology? Third, is the hypothesis obviated by consideration of the functional matrix concept of skull development, in which osseous growth is posited to be governed by surrounding soft tissues (e.g., muscle and tendon) and developing spaces (e.g., the nasal capsule)? The different perspectives explored by these questions suggest that the validity of the hypothesis, despite having a defensible theoretical rationale, is likely to be context‐specific. A direct role for strain magnitude in conditioning morphological variation is difficult to demonstrate either comparatively or theoretically, and it is unlikely that a single strain threshold or interval can be directly associated with elevated variation in the skeleton. The conceptual framework of the functional matrix (which allows for independent growth among different regions of the skull) conceivably contravenes the premise of a uniform relationship of strain magnitude to morphological variability. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Atelinae phylogenetic relationships: The trichotomy revived?
Authors: Collins A.C.
Published: July 2004

This research examines phylogenetic relationships between members of the Atelinae subfamily (Alouatta,Ateles,Brachyteles, andLagothrix), based on analysis of three genetic regions. Two loci, cytochrome c oxidase subunit II (COII) and the hypervariable I portion of the control region, are part of the mitochondrial genome. The other is a single‐copy nuclear gene, Aldolase A Intron V. Analysis of these genetic regions provides support for tribe Alouattini containing theAlouattaspecies, while tribe Atelini contains the other three genera. However, these three genetic regions produce conflicting results for relationships among tribe Atelini members. Previous genetic studies supported groupingBrachyteleswithLagothrix, leavingAtelesin a separate subclade. The present data sets vary based on the genetic region analyzed and method of analysis suggesting all possible cladistic relationships. These results are more consistent with investigations of morphology and behavior among these primates. The primary cause of discrepancy between this study and previous genetic studies is postulated to reside in increased sampling in the present study of genetic variation among members of the Atelinae, specificallyAteles. The present study utilized samples ofAtelesfrom all postulated species for this genetically variable primate, while previous studies used only one or two species ofAteles. This paper demonstrates that shifting relationships are produced when different species ofAtelesare used to reconstruct phylogenies. This research concludes that a trichotomy should still be supported between members of tribe Atelini until further analyses, which include additional Atelinae haplotypes are conducted. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Functional anatomy of the olecranon process in hominoids and plio‐pleistocene hominins
Authors: Drapeau Michelle S.M.
Published: July 2004

This study examines the functional morphology of the olecranon process in hominoids and fossil hominins. The length of the bony lever of the triceps brachii muscle (TBM) is measured as the distance between the trochlear articular center and the most distant insertion site of the TBM, and olecranon orientation is measured as the angle that this bony lever makes with the long axis of the ulna. Results show thatHomo,Pan,Gorilla, most monkeys, and theAustralopithecusfossils studied have similar relative olecranon lengths. Suspensory hominoids andAteleshave shorter olecranons, suggesting, in some instances, selection for greater speed in extension. The orientation that the lever arm of the TBM makes with the long axis of the ulna varies with preferred locomotor mode. Terrestrial primates have olecranons that are more posteriorly oriented as body size increases, fitting general models of terrestrial mammalian posture. Arboreal quadrupeds have more proximally oriented lever arms than any terrestrial quadrupeds, which suggests use of the TBM with the elbow in a more flexed position. Olecranon orientation is not consistent in suspensory hominoids, although they are all characterized by orientations that are either similar or more posterior than those observed in quadrupeds.Homoand the fossils have olecranons that are clearly more proximally oriented than expected for a quadruped of their size. This suggests thatHomoandAustralopithecusused their TBM in a flexed position, a position most consistent with manipulatory activities. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Functional Models for Rhodium‐Mediated Olefin‐Oxygenation Catalysis
Authors: de Bruin Bas , Budzelaar Peter H. M. , Gal Anton W.
Published: July 2004

Oxygenation of CH and CC bonds of hydrocarbons with H2O2 and O2 is an important industrial method to convert mineral oil into useful chemicals. Despite their enormous economic impact, these reactions are still not fully understood. In the early 1970s, the potential of Rh and Ir complexes for olefin oxygenation was investigated intensively. Simple inorganic salts of these metals proved to be rather useless for industrial application when compared with the traditional Wacker system. However, the appropriate choice of ligands allows the stepwise oxidation of olefins at Rh and Ir. These systems are therefore useful to study mechanistic details of substrate binding and CO bond formation at the catalytic metal center. Insight from these model studies helps in understanding the catalytic reactions at these (and possibly other) metal centers. Further insight into the differences between the Rh system and traditional Wacker‐type oxidation at Pd may lead to useful applications.
Cover Picture: Platonic Gold Nanocrystals (Angew. Chem. Int. Ed. 28/2004)
Authors: Kim Franklin , Connor Stephen , Song Hyunjoon , Kuykendall Tevye , Yang Peidong
Published: July 2004

Platonic shapes of gold nanocrystals are prepared by a modified polyol process in the presence of the surface‐regulating polymer poly(vinyl pyrrolidone). P. Yang and co‐workers describe in their Communication on page 3673 ff. how the careful regulation of the growth rate along different crystallographic directions allows exquisite shape control. The drawing in the center of the cover picture was proposed by the astronomer Johannes Kepler in the 17th century, in which one platonic solid fits between each pair of planetary spheres.
Synthesis and characterization of acrylic rubber/silica hybrid composites prepared by sol‐gel technique
Authors: Bandyopadhyay Abhijit , Bhowmick Anil K. , De Sarkar Mousumi
Published: July 2004

The organic–inorganic hybrid composites comprising acrylic rubber and silica were synthesized through sol–gel technique at ambient temperature. The composites were generated through the acid‐catalyzed hydrolysis and subsequent condensations of inorganic tetraethoxysilane (TEOS) in the organic acrylic rubber (ACM), solvated in tetrahydrofuran. The morphology of the hybrid materials was investigated by using the transmission electron microscope (TEM) and scanning electron microscope (SEM). Transmission electron micrographs revealed that the silica particles, uniformly distributed over the rubber matrix, are of nanometer scale (20–90 nm). The scanning electron micrographs demonstrated the existence of silica frameworks dispersed in the rubber matrix of the hybrid composites. The X‐ray silicon mapping also supported that observation. There was no evidence of chemical interaction between the rubber phase and the dispersed inorganic phase, as confirmed from the infrared spectroscopic analysis and solubility measurements. Dynamic mechanical analysis indicated mechanical reinforcements within the hybrid composites. The composites containing in situ silica, formed by sol–gel technique, demonstrated superior tensile strengths and tensile modulus values at 300% elongations with increasing proportions of tetraethoxysilane. However, the improvements in physical properties with similar proportions of precipitated silica were not significant. Maximum tensile strength and tensile modulus were obtained when the rubber phase in the hybrid composites was cured with ammonium benzoate and hexamethylenediamine carbamate system, as compared with benzoyl peroxide cured system. Thermal stability of the hybrid composites was not improved appreciably with respect to the virgin rubber specimen. Residue analysis from thermogravimetric study together with infrared spectroscopic analysis indicated the presence of unhydrolyzed tetraethoxysilane in the hybrid composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2579–2589, 2004
Biodegradable polymers. III. Spectral, thermal, mechanical, and morphological properties of cross‐linked furfural–soy protein concentrate
Authors: Swain S. N. , Rao K. K. , Nayak P. L.
Published: July 2004

Soy protein concentrate, a potential alternative of petrochemical polymers, has been crosslinked with furfural at 0.5,1, 2.5, 5, and 7.5% (w/w). The materials were then compression‐molded into plastic tensile bars and tested for tensile and yield strength, percentage elongation, and water absorption. The infrared spectra of the crosslinked product have been studied. The degradation pattern of the crosslinked product has been monitored by TGA method. A computerized LOTUS package method developed by us has been used for evaluating the kinetic parameters. The morphology as well as the biodegradability of the crosslinked product has also been investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2590–2596, 2004
Preparation and characterization of chitosan based micro networks: Transposition to a prilling process
Authors: Martinez L. , Agnely F. , Bettini R. , Besnard M. , Colombo P. , Couarraze G.
Published: July 2004

Beads of chitosan (CS) crosslinked network and of chitosan/poly(ethylene oxide) (CS/PEO) semi‐interpenetrating network (semi‐IPN) were prepared by a dropping technique and characterized. PEO content in the beads of semi‐IPN was determined by gel permeation chromatography. CS crosslinking ratio was evaluated qualitatively by ATR‐FTIR spectroscopy and quantitatively by UV spectrophotometry. After drying in a fluidized bed apparatus, a monodisperse population of well individualized, spherical, and smooth particles was obtained. It was shown that bead collapsus during the drying stage was avoided thanks to the chemical crosslinking of CS chains. By the prilling, or laminar jet break‐up technology, production at a larger scale was also achieved. This process allowed the formation of a row of well calibrated drops of polymer solution under the influence of a vibration. Polymer solution characteristics, particularly viscosity, constituted a critical factor in the feasibility of the prilling process. Transposition of the formulation was managed through the optimization of process parameters such as vibration frequency, amplitude, and flow rate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2550–2558, 2004
Copolymerization of ethylene–propylene using high‐activity bi‐supported Ziegler–Natta TiCl4 catalyst
Authors: Zohuri G. H. , Mortazavi M. M. , Jamjah R. , Ahmadjo S.
Published: July 2004

Heterogeneous Ziegler–Natta TiCl4 catalyst using MgCl2 and SiO2 as supports was prepared under controlled conditions. Mg(OEt)2 was used as a starting material and was expected to convert to active MgCl2 during catalyst preparation. Due to the high surface area and good morphological control, SiO2 was chosen as well. Slurry copolymerization of ethylene and propylene (EPM) was carried out in dry n‐heptane by using the catalyst system SiO2/MgCl2/TiCl4/EB/TiBA or TEA/MPT/H2 at temperatures of 40–70°C, different molar ratios of alkyl aluminum : MPT : Ti, hydrogen concentrations, and relative and total monomers pressure. Titanium content of the catalyst was 2.96% and surface area of the catalyst was 78 m2/g. Triisobutyl aluminum (TiBA) and triethyl aluminum (TEA) were used as cocatalysts, while ethyl benzoate (EB) and methyl p‐toluate (MPT) were used as internal and external donors, respectively. H2 was used as a chain‐transfer agent. Good‐quality ethylene propylene rubber (EPR) of rubber was obtained at the ratio of [TiBA] : [MPT] : [Ti] = 320 : 16 : 1 and polymerization temperature was 60°C. When TiBA was used as a cocatalyst, a higher and more rubberlike copolymer was obtained. For both of the cocatalysts, an optimum ratio of Al/Ti was obtained relative to the catalyst productivity. Ethylene content of the copolymer obtained increased with increasing TiBA concentration, while inverse results were obtained by using TEA. Addition of H2 increased the reactivity of the catalyst. The highest product was obtained when 150 mL H2/L solvent was used. Increasing temperature from 40 to 70°C decreased the productivity of the catalyst, while irregular behavior was observed on ethylene content. Relative pressure of PP/PE = 1.4 : 1 and total pressure of 1 atm was the best condition for the copolymerization. Polymers with ethylene contents of 25–84% were obtained. Increasing ethylene content of EPR decreased Tg of the polymer obtained to a limiting value. Viscosity‐average molecular weight (Mv) decreased with increasing temperature and TiBA and H2 concentration. However, increasing the polymerization time increased the Mv. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2597–2605, 2004
Viscosity behavior of acrylonitrile–ammonium itaconate copolymer solutions in dimethyl sulfoxide
Authors: Hou Chen , Ying Liang , Wang Cheng‐Guo
Published: July 2004

The viscosity behavior of dimethyl sulfoxide (DMSO) solutions of acrylonitrile–ammonium itaconate copolymer is discussed. The intrinsic viscosity was determined by an Ubbelohde viscometer. It is shown that an increase in the viscosity of acrylonitrile–ammonium itaconate copolymer solutions with time is considerably reduced by mechanical mixing. The viscosity of copolymer solutions with dimethyl formamide as an additive decreases monotonically. The viscosity of copolymer solutions decreases with the addition of H2O, and as the content of H2O in DMSO goes beyond 3 wt %, the viscosity shows a trend toward increase. The intrinsic viscosity decreases quickly with the addition of NaCl. As the concentration of NaCl goes beyond 0.015 mol/L, the viscosity increases solwly. The viscosity of copolymer solutions containing sodium ethoxide and sodium hydroxide appears to increase after an initial drop. The viscosity of copolymer solutions upon the addition of diethylamine increases continuously with time and changes in viscosity become less prominent after a period of a few hours. The effects of bases on the tacticity of highly isotactic copolymers follow the order of base strength. Diethylamine is more effective for moderating the stabilization exotherm of highly isotactic copolymers compared to sodium ethoxide and sodium hydroxide. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2622–2626, 2004
Biodegradable packaging foams of starch acetate blended with corn stalk fibers
Authors: Ganjyal G. M. , Reddy N. , Yang Y. Q. , Hanna M. A.
Published: July 2004

Starch acetate–corn fiber foams were prepared by extrusion. Corn starch was acetylated (DS 2) to introduce thermoplastic properties. Corn stalks were treated with sodium hydroxide to remove the lignin and to obtain purified cellulose fibers. Starch acetate was blended with treated fiber at concentrations of 0, 2, 6, 10, and 14% (w/w) and extruded in a corotating twin‐screw extruder with 12 to 18% w/w ethanol content and 5% talc as a nucleating agent. The samples were extruded at 150°C and selected physical and mechanical properties were evaluated. Micrographic properties were analyzed using scanning electron microscopy to observe the interaction of fiber and starch. Fiber incorporation at the lower concentrations enhanced the physical properties of the foams. Fiber contents greater than 10% decreased expansion and increased density and shear strength. Good compatibility between starch and corn fiber was observed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2627–2633, 2004
Contraction stress build‐up of anisotropic conductive films (ACFs) for flip‐chip interconnection: Effect of thermal and mechanical properties of ACFs
Authors: Kwon Woon‐Seong , Paik Kyung‐Wook
Published: July 2004

The important mechanical mechanism for the electrical conduction of anisotropic conductive films (ACFs) is the joint clamping force after the curing and cooling processes of ACFs. In this study, the mechanism of shrinkage and contraction stress and the relationship between these mechanisms and the thermomechanical properties of ACFs were investigated in detail. Both thickness shrinkages and modulus changes of four kinds of ACFs with different thermomechanical properties were experimentally investigated with thermomechanical and dynamic mechanical analysis. Based on the incremental approach to linear elasticity, contraction stresses of ACFs developed along the thickness direction were estimated. Contraction stresses in ACFs were found to be significantly developed by the cooling process from the glass‐transition temperature to room temperature. Moreover, electrical characteristics of ACF contact during the cooling process indicate that the electrical conduction of ACF joint is robustly maintained by substantial contraction stress below Tg. The increasing rate of contraction stresses below Tg was strongly dependent on both thermal expansion coefficient (CTE) and elastic modulus (E) of ACFs. A linear relationship between the experimental increasing rate and E × CTE reveals that the build‐up behavior of contraction stress is closely correlated with the ACF material properties: thermal expansion coefficient, glassy modulus, and Tg. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2634–2641, 2004
New liquid polysulfide polymer terminated with silyl group
Authors: Matsui Tatsuro , Nakajima Masashi , Nonaka Toshiaki , Dokoshi Noriaki
Published: July 2004

The terminal SH of liquid polysulfide polymer was capped with a silyl group. This polymer was hydrolyzed immediately by moisture at ambient temperature and returned to the original polymer. The compounds of this new polymer and the various curing agents of the conventional polysulfide polymer became moisture curable and of use as one‐component sealants and adhesives. The curing speed of these compounds is very fast compared with that of not only conventional one‐component polysulfide sealants, by more than three times, but also of other one‐component sealants at 20°C under 30% humidity. Their storage stability is good. Their cured products showed physical properties comparable to those of the two‐component polysulfide compounds. In particular, the compound of this polymer and isocyanate prepolymer showed good elasticity and good weatherability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2642–2649, 2004
Modeling the tensile behavior of fiber bundles with irregular constituent fibers
Authors: He Wendy W. , Wang Xungai
Published: July 2004

In this article, the effect of fiber dimensional irregularities on the tensile behavior of fiber bundles is modeled with the finite element method. The fiber dimensional irregularities are simulated with sine waves of different magnitudes. The specific‐stress/strain curves of fiber bundles and their constituent single fibers are obtained and compared. The results indicate that fiber diameter irregularity along the fiber length has a significant effect on the tensile behavior of fiber bundles. For a bundle of uniform fibers of different diameters, all the constituent fibers will break simultaneously, regardless of the fiber diameter. Similarly, if fibers within a bundle have the same pattern and level of diameter irregularity along the fiber length, the fibers will break at the same time, also regardless of the difference in the average diameter of each fiber. In these cases, the specific‐stress/strain curve for the bundle overlaps with that of the constituent fibers. When a fiber bundle consists of single fibers with different levels of diameter irregularities, the specific‐stress/strain and load–elongation curves of the fiber bundle have a stepped or ladder shape. The fiber with the highest irregularity breaks first, even when the thinnest section of the fiber is still coarser than the diameter of a very thin but uniform fiber in the bundle. This study suggests that fiber diameter irregularity along the fiber length is a more important factor than the fiber diameter itself in determining the tensile behavior of a fiber bundle consisting of irregular fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2664–2668, 2004
Disappointing long-term results of the artificial anal sphincter for faecal incontinence
Authors: Altomare D F , Binda G A , Dodi G , La Torre F , Romano G , Rinaldi M , Melega E
Published: July 2004

Long term results of ABS disappointing
New insights into the development of popliteal cysts
Authors: Labropoulos N , Shifrin D A , Paxinos O
Published: July 2004

Background

This prospective study was designed to investigate the aetiology of popliteal (Baker's) cysts.

Methods

Some 426 legs in 312 individuals were investigated with ultrasonography for the presence of a popliteal cyst. Participants included healthy volunteers, patients with a painful knee, and a group of patients with signs and symptoms of deep vein thrombosis (DVT). The location, thickness and content of all cysts were recorded. In addition, the popliteal fossa was dissected in four cadaver knees.

Results

The prevalence of popliteal cyst increased with age and was significantly higher in those aged over 50 years (P < 0·001). Compared with controls (incidence 3·0 per cent), cysts were more common in patients with DVT symptoms (9·5 per cent; P = 0·141) and those with painful knees (19·8 per cent; P < 0·001). All cysts were located in the posteromedial aspect of the popliteal fossa; the majority extended between the deep fascia and the medial head of the gastrocnemius muscle. At this level an area without external support of the posterior capsule was identified between the two expansions of the semimembranosus muscle from the medial side (the oblique popliteal ligament and the expansion over the popliteus muscle) and the posterior cruciate ligament from the lateral side. This area was also located in the knee dissections. No association was found between popliteal cyst and acute DVT.

Conclusion

Popliteal cysts are relatively common in patients over 50 years old with a painful knee or with signs and symptoms of DVT. They form in the posteromedial popliteal fossa because the synovial capsule does not provide anatomical support in this region.
Quantitation of the large polypeptide glucagon by protein precipitation and LC/MS
Authors: Delinsky David C. , Hill Kim T. , White Catherine A. , Bartlett Michael G.
Published: July 2004

We present a method for the quantitation of glucagon from rat plasma by protein precipitation and LC/MS. No internal standard was used, as a labeled standard was not available and similar peptides did not show comparable extraction characteristics to glucagon. The LC system included a Keystone C18, 300 Å pore size column; a linear gradient was used with a mobile phase consisting of water and acetonitrile, each with 0.2% acetic acid and 0.02% trifluoroacetic acid. Glucagon was detected with the mass spectrometer in positive ion mode monitoring the 4+ charge state at m/z 871.7. The method had an approximated limit of detection of 1 ng/mL. The lower limit of quantitation (LLOQ) was 25 ng/mL (7.2 fmol/mL), which could be reduced with an appropriate internal standard. External calibration was used and calibration curves were found to be linear over the range from 25 to 1000 ng/mL (7.2 to 290 fmol/mL). The method showed a high degree of precision and accuracy both within and between runs at four validation points, including the LLOQ. Copyright © 2004 John Wiley & Sons, Ltd.
A validated HPLC assay to monitor riluzole plasma or serum concentrations in patients with amyotrophic lateral sclerosis
Authors: van Kan H. J. M. , Spieksma M. , Groeneveld G. J. , Toraño J. Sastre , van den Berg L. H. , Guchelaar H. J.
Published: July 2004

A specific, accurate and precise high‐performance liquid chromatographic assay was developed for the determination of riluzole, a drug used to treat patients with amyotrophic lateral sclerosis. Samples were treated by extraction with dichloromethane followed by reversed‐phase chromatography with ultraviolet detection at 260 nm. Preset validation criteria were met from 20 to 2000 ng/mL with a linear response curve. Extraction recovery of riluzole was 65–76%. The accuracy of the method was 102–103%. Intra‐ and inter‐day coefficients of variation were in the ranges 2.8–4.9% and 1.8–9.7%. A detection limit of 5 ng/mL was found. Determination of concentrations in serum and plasma resulted in similar results below 500 ng/mL. At higher values a matrix effect cannot be excluded. This presented method can be used to monitor plasma or serum levels in ALS patients treated with riluzole. Copyright © 2004 John Wiley & Sons, Ltd.
Photolysis of NSAIDs. IV. Photoproducts of zomepirac determined by LC‐ESI‐MS
Authors: Wang Ching‐Chiung , Chen Fu‐An , Chen Chih‐Jui , Chao Su‐Hui , Wu An‐Bang
Published: July 2004

A sample of 10 mm zomepirac in methanol was photo‐irradiated with a Hanovia 200 W high‐pressure quartz Hg lamp for 14 days. In total, four photoproducts were observed from the HPLC chromatogram. The preparative HPLC included an YMC‐Pack Pro C18 column (250 × 20 mm i.d.), a mobile phase of CH3CN–CH3OH–1%HOAc (10:60:30, v/v/v), and UV detection at 254 nm. The most probable structures of the four photoproducts were determined by LC‐MS. Two major photoproducts were separated, and their structures were further conﬁrmed by the spectroscopic methods. A reaction scheme of zomepirac was proposed that the photochemical reaction routes occur mainly via bond ﬁssion between carbonyl–pyrrolyl groups (α‐cleavage of a ketone), and decarboxylation followed by oxidation with singlet oxygen to produce an aldehyde. Copyright © 2004 John Wiley & Sons, Ltd.
An optimized protocol for nano‐LC‐MALDI‐TOF‐MS coupling for the analysis of proteolytic digests of glycoproteins
Authors: Lochnit Günter , Geyer Rudolf
Published: July 2004

Matrix‐assissted laser desorption ionization time‐of‐ﬂight mass spectrometry (MALDI‐TOF‐MS) analyses of complete proteolytic digests are often hampered by contaminations and the complexity of the sample. This results in suppression effects and the formation of adducts which are difﬁcult to assign, thus leading to low scores in database searches. In particular, signals of post‐translationally modiﬁed peptides such as glycopeptides are often of low intensity or completely suppressed. Online liquid chromatography electrospray ionization mass spectrometry (ESI‐MS) can, in part, overcome this problem, but the analytes are completely consumed during the run. Coupling of nano‐ﬂow HPLC (nano‐LC), microfractionation and MALDI‐TOF‐MS combines separation and high‐sensitivity UV detection with the possibility of collecting fractionated peptides and preserving the sample for detailed mass spectrometric analyses. Here we report on an optimized protocol for nano‐LC‐MALDI‐TOF‐MS analyses of glycoproteins. This protocol improves spectral quality, resulting in better protein identiﬁcation scores in database searches. Furthermore, post‐translationally modiﬁed peptides could be detected with higher sensitivity by changing the experimental conditions, allowing assignment, localization and characterization of the respective carbohydrate substituents. Copyright © 2004 John Wiley & Sons, Ltd.
Identiﬁcation and determination of effective components in Euphrasia regelii by capillary zone electrophoresis
Authors: Shuya Cui , Shengda Qi , Xingguo Chen , Zhide Hu
Published: July 2004

A capillary zone electrophoresis (CZE) method has been developed for simultaneous determination of eukovoside, cinnamic acid and ferulic acid in Euphrasia regelii for the ﬁrst time. The electrophoresis buffer was 20 mmol/L sodium borate containing 10% (v/v) methanol (pH 8.50). The effects of concentration of borate and electrolyte pH on electrophoretic behavior and separation were studied. Regression equations revealed linear relationships (correlation coefﬁcients 0.9995–0.9998) between the peak area of each analyte and the concentration. The levels of analytes in the different parts of Euphrasia regelii were easily determined with recoveries ranging from 95.5 to 104.2%. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of ropivacaine and antipyrine by high performance liquid chromatography and its application to the in vitro transplacental study
Authors: Zuo Ming , Duan Geng‐Li , Ge Zhen‐Gong
Published: July 2004

A simple and reliable RP‐HPLC method has been developed for the simultaneous determination of ropivacaine and antipyrine in perfusate samples. Samples were analyzed on an ODS column with UV detection at 210 nm after liquid–liquid extraction. The mobile phase consisted of potassium dihydrogenphosphate (25 mm, adjusted to pH 5.0 with phosphoric acid)–acetonitrile (79:21, v/v). The method has been validated to be precise, accurate and linear. It has been applied to the investigation of placental transfer of ropivacaine via a dually perfused cotyledon model of human placenta in vitro. Copyright © 2004 John Wiley & Sons, Ltd.
Chiral Recognition by Resorcin[4]arene Receptors: Intrinsic Kinetics and Dynamics
Authors: Tafi Andrea , Botta Bruno , Botta Maurizio , Delle Monache Giuliano , Filippi Antonello , Speranza Maurizio
Published: July 2004

Molecular recognition of representative amino acids (A) by a chiral amido[4]resorcinarene receptor (1L) was investigated in the gas phase by ESI‐FT‐ICR mass spectrometry. The ligand displacement reaction between noncovalent diastereomeric [1L⋅H⋅A]+complexes and the 2‐aminobutane enantiomers (B) exhibits a distinct enantioselectivity with regard to both the leaving amino acid A and the amine reactant B. The emerging selectivity picture, discussed in the light of molecular mechanics and molecular dynamics calculations, points to chiral recognition by1L, as determined by the effects of the host asymmetric frame on the structure, stability, and rearrangement dynamics of the diastereomeric [1L⋅H⋅A]+complexes and the orientation of the amine reactant B in encounters with [1L⋅H⋅A]+. The results contribute to the development of a dynamic model of chiral recognition of biomolecules by enzyme mimics in the unsolvated state.
The kallikrein‐kinin system, angiotensin converting enzyme inhibitors and insulin sensitivity
Authors: Damas J. , Garbacki N. , Lefèbvre P. J.
Published: July 2004

The therapeutic use of angiotensin converting enzyme (ACE) inhibitors, at a large scale, in arterial hypertension has showed that these molecules can exert beneficial effects on insulin sensitivity and may reduce the occurrence of type 2 diabetes mellitus. One hypothesis explaining these effects of ACE inhibitors may relate to their capacity to interfere with bradykinin (BK) metabolism and action. BK may participate in the regulation of substrate utilization by several tissues by improving blood flow and substrate delivery to the tissues and also by promoting translocation of glucose transporters. Moreover, BK has been shown to increase phosphorylation of insulin receptor and its cell substrates. BK also appears to improve the release of insulin. Furthermore, insulin may activate the kallikrein‐kinin system, which consequently may increase its metabolic effects. However, in experimental diabetes mellitus, BK can participate to the inflammatory reaction leading to Langerhans islets destruction. In diabetes, whereas tissue kallikrein mRNA levels were reduced in several organs, an overexpression of kinin receptors, an increase in plasma levels of kininogens and kallikrein and an activation of the kinin system have all been reported. Lastly, kinins may be involved in the development of diabetic nephropathy. Reduction of kinin metabolism by ACE inhibitors might be involved in the beneficial effects exerted by these compounds in diabetic kidney functions. Copyright © 2004 John Wiley & Sons, Ltd.
Diabetes mellitus and alcohol
Authors: van de Wiel Albert
Published: July 2004

Alcohol influences glucose metabolism in several ways in diabetic patients as well as in non‐diabetic patients. Since alcohol inhibits both gluconeogenesis and glycogenolysis, its acute intake without food may provoke hypoglycaemia, especially in cases of depleted glycogen stores and in combination with sulphonylurea. Consumed with a meal including carbohydrates, it is the preferred fuel, which may initially lead to somewhat higher blood glucose levels and hence an insulin response in type 2 diabetic patients. Depending on the nature of the carbohydrates in the meal, this may be followed by reactive hypoglycaemia.

Moderate consumption of alcohol is associated with a reduced risk of atherosclerotic disorders. Diabetic patients benefit from this favourable effect as much as non‐diabetic patients. Apart from effects on lipid metabolism, haemostatic balance and blood pressure, alcohol improves insulin sensitivity. This improvement of insulin sensitivity may also be responsible for the lower incidence of type 2 diabetes mellitus reported to be associated with light‐to‐moderate drinking. In case of moderate and sensible use, risks of disturbances in glycaemic control, weight and blood pressure are limited.

Excessive intake of alcohol, however, may not only cause loss of metabolic control, but also annihilate the favourable effects on the cardiovascular system. Copyright © 2004 John Wiley & Sons, Ltd.
PLCγ2 regulates Bcl‐2 levels and is required for survival rather than differentiation of marginal zone and follicular B cells
Authors: Bell Sarah E. , Vigorito Elena , McAdam Simon , Reynolds Helen M. , Caraux Anouk , Colucci Francesco , Turner Martin
Published: July 2004

B cells from phospholipase C (PLC)γ2‐deficient mice express reduced levels of the pro‐survival protein Bcl‐2 and show a defect in the development of transitional T3 and marginal zone (MZ) B cells that reflects reduced B cell survival. Introduction of a bcl‐2 transgene restored the numbers of MZ, T3 and follicular B cells in PLCγ2–/– mice. Restricting the B cell repertoire in PLCγ2‐deficient mice by the introduction of a BCR transgene resulted in a striking reduction in the number of IgM‐positive B cells and a paucity of IgD‐expressing cells in the spleen which was also rescued by the bcl‐2 transgene. BCR‐stimulated ERK and IκBα phosphorylation were PLCγ2 dependent, while calcium flux was reduced, but not abrogated, in the absence of PLCγ2, suggesting an ancillary role for PLCγ1. The bcl‐2 transgene rescued development of PLCγ2–/– B cells and serum IgM levels but did not restore BCR‐mediated signaling, proliferation or serum IgG3 levels. These data suggest that PLCγ2 performs a critical role in B cell development through regulation of survival rather than differentiation.
CD4‐induced down‐regulation of T cell adhesion to B cells is associated with localization of phosphatidyl inositol 3‐kinase and LFA‐1 in distinct membrane domains
Authors: Trucy Maÿlis , Barbat Christiane , Sorice Maurizio , Fischer Alain , Mazerolles Fabienne
Published: July 2004

We have previously shown that binding of anti‐CD4 antibody inhibit LFA‐1‐dependent adhesion between CD4+ T cells and B cells in a p56lck and a PI3‐kinase‐dependent manner. In this work, we investigated with two different T cell lines (Jurkat and A201) whether CD4 binding could alter interactions of the proteins putatively involved in this adhesion regulatory pathway. Anti‐CD4 binding was shown to induce a transient association between PI3‐kinase and LFA‐1, which took place in different regions of the plasma membrane. It was detected in detergent soluble membrane but also in detergent insoluble membrane consisting in raft microdomains, composed of GM1 and/or GM3 gangliosides. These results show that anti‐CD4 Ab could modify the interaction between LFA‐1 and signaling molecules, such as PI3‐kinase and induce, in part, their recruitment in raft domains. By using specific inhibitors, raft integrity and CD4 association with GM3 were found necessary for observing the CD4‐dependent inhibition of LFA‐1‐mediated adhesion. These results strongly suggest that these molecular rearrangements in the membrane are necessary to induce down‐regulation of LFA‐1‐mediated adhesion.
Antigenicity and immunogenicity of peptide analogues of a low affinity peptide of the human telomerase reverse transcriptase tumor antigen
Authors: Hernández Javier , Schoeder Kim , Blondelle Sylvie E. , Pons Fancisco Garcia , Lone Yu Chun , Simora April , Langlade‐Demoyen Pierre , Wilson Darcy B. , Zanetti Maurizio
Published: July 2004

Human telomerase reverse transcriptase (hTRT) is a potential target for therapeutic vaccination against cancer. Therefore, it is critically important to identify T cell epitopes useful to induce cytotoxic T cell responses. Here we used a positional scanning combinatorial peptide library to identify peptide analogues for a previously characterized low affinity hTRT peptide (p572). From an initial library containing over 300 billion different peptides and through successive rounds of selection, we retained 72 candidate peptide analogues for further assessment of antigenicity and in vivo immunogenicity in HLA A2.1‐transgenic mice. While antigenically cross‐reactive with p572, only a fraction of these peptides was immunogenic in mice. Immunogenicity appeared to correlate with the stability of binding to the MHC molecule and the presence of HLA A2.1 anchor residues in position 2 and 9. Two peptides differing by five residues from the reference p572 (p49 and p50) were more effective than p572 in inducing CTL cross‐reacting with p572 in HLA A2.1‐transgenic mice. Both peptides also expanded specific CTL in peripheral blood lymphocytes of normal human volunteers ex vivo. The present study shows that positional scanning combinatorial peptide libraries can be used to identify hTRT peptide analogues for inclusion in a cancer vaccine.