bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic study of hindered amine light stabilizer photografting in low density polyethylene films under natural weathering conditions
Authors: Kaci M. , Hebal G. , Benhamida A. , Boukerrou A. , Djidjelli H. , Sadoun T. 
Published: October 2004

AbstractThe photografting kinetic of a hindered amine light stabilizer (HALS) was studied in low density polyethylene (LDPE) films under natural weathering conditions. The HALS (PBH‐3) was added to the polymer at a concentration of 0.3% (w/w). The photografting kinetic of polymer bound HALS (PBH‐3) was determined by direct spectroscopic measurements through the absorption band area of the stabilizer centered at 308 nm in the UV spectra and 1605 cm−1 in Fourier transform IR (FTIR) spectra, which correspond to benzylidene malonate ester and benzylidene malonic groups, respectively. In parallel, measurements were carried out on the free PBH‐3 content after chloroform extraction of the photostabilizer from the polymer matrix by means of UV and gas chromatography methods. The results showed that in natural weathering the grafting of PBH‐3 occurred in the LDPE film after very short exposure times of 127 and 168 h as determined by UV and FTIR, respectively. Moreover, the curves describing both the photografting and the free HALS kinetics exhibited similar profiles. The mechanism of photografting implies a rapid photoreaction between the methylenic double bond of the stabilizer and the macroalkyl radicals of the polymer, resulting in formation of polymer‐bonded aminyl derivatives of the stabilizer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1524–1532, 2002; DOI 10.1002/app.10492
New soybean oil–styrene–divinylbenzene thermosetting copolymers. v. shape memory effect
Authors: Li Fengkui , Larock Richard C. 
Published: October 2004

AbstractA series of new shape memory polymers are synthesized by the cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil), and/or conjugated LoSatSoy oil with styrene and divinylbenzene, norbornadiene, or dicyclopentadiene initiated by boron trifluoride diethyl etherate or related modified initiators. The shape memory properties of the soybean oil polymers are characterized by the deformability (D) of the materials at temperatures higher than their glass‐transition temperatures (Tg), the degree to which the deformation is subsequently fixed at ambient temperature (FD), and the final shape recovery (R) upon being reheated. It is found that a Tg well above ambient temperature and a stable crosslinked network are two prerequisites for these soybean oil polymers to exhibit shape memory effects. Good shape memory materials with high D, FD, and R values are prepared by controlling the crosslink densities and the rigidity of the polymer backbones. The advantage of the soybean oil polymers lies in the high degree of chemical control over the shape memory characteristics. This makes these materials particularly promising in applications where shape memory properties are desirable. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1533–1543, 2002; DOI 10.1002/app.10493
Conversion of soybean oil into ion exchange resins: Removal of copper (II), nickel (II), and cobalt (II) ions from dilute aqueous solution using carboxylate‐containing resin
Authors: Liu Z. S. , Erhan S. Z. 
Published: October 2004

AbstractAn ion‐exchange resin containing carboxylic acid groups was prepared by reaction of epoxidized soybean oil with triethylene tetramine, followed by hydrolysis of glycerides by using sodium hydroxide solution. The cation exchange capacity of the resins was determined to be 3.50 mequiv/g. The adsorption capacity for Cu2+, Ni2+, and Co2+ on the obtained resin at pH 5.0 was found to be 192, 96, and 78 mg/g, respectively. Effect of pH on the adsorption capacity for copper (II), nickel (II), and cobalt (II) ions were also studied. Cu2+, Ni2+, and Co2+ were adsorbed at a pH above 3. These metal ions adsorbed on the resin are easily eluted by using 1N HCl solution. The selectivity of the resin for Cu2+ from mixtures containing Cu2+/Co2+/Ni2+ ions in the presence of sodium chloride was also investigated © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2386–2396, 2002
Studies on fly ash–filled epoxy‐cast slabs under compression
Authors: Kulkarni S. M. , Kishore  
Published: October 2004

AbstractFilling a polymer with particulate material is generally attempted to improve the polymer properties and also realize some reduction in the cost. In the present work, we attempted to study the viability of using fly ash, an industrial waste with good mechanical properties, as a filler in epoxy. Initial low volumes of filler display an improvement in compressive strength and modulus. The experimental values of strength and modulus are also found to correlate well with those predicted by the rule of mixtures and modified Kerner's equation. At higher volume fractions, the decline in these properties is explained in the context of both percolation theory and Griffith's theory. The processes of failure initiation and propagation proposed are examined from the viewpoint of observations on the surfaces of compression‐failed samples in SEM. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2404–2410, 2002
Photo‐induced emulsion polymerization of vinyl acetate in the presence of poly(oxyethylene)10 nonyl phenyl ether ammonium sulfate, an anionic emulsifier (I)
Authors: Mah Soukil , Koo Donghun , Jeon Hyunjeong , Kwon Soonhong 
Published: October 2004

AbstractPoly(vinyl alcohol) (PVA) having a number‐average degree of polymerization of 7000 was obtained from the poly(vinyl acetate) (PVAc) having a number‐average degree of polymerization 9000, a product of photo‐induced emulsion polymerization of vinyl acetate (VAc), carried out at 0°C, using poly(oxyethylene)10 nonyl phenyl ether ammonium sulfate as an anionic emulsifier. It was found that 100% conversion is always attained in the whole range of the investigation and the emulsifier plays an important role in the initiation process. The applicability of the photo‐induced emulsion polymerization system to a relatively large‐scale production was tested by using an apparatus equipped with an internal high‐pressure Hg lamp with a capacity of several hundred grams per batch under nitrogen atmosphere. It was found that both the rate of polymerization and the degree of polymerization of resulting polymers are slightly lower than those obtained from corresponding small‐scale polymerizations prepared on a high vacuum system because of the presence of oxygen. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2425–2431, 2002
Thermoreversible hydrogels. XV. Swelling behaviors and drug release for thermoreversible hydrogels containing silane monomers
Authors: Lee Wen‐Fu , Yuan Wen‐Yang 
Published: October 2004

AbstractThree series of thermosensitive copolymeric hydrogels were prepared from [3‐(methacryloyloxy)propyl]trimethoxysilane (MPTMOS), [2‐(methacryloyloxy)ethoxy]trimethylsilane (METMS), and (methacryloyloxy)trimethylsilane (MTMS), referred to as the silane monomer, and N‐isopropylacrylamide (NIPAAm) by solution polymerization. The influence of the structures and amounts of silane monomers on the swelling and drug‐released behaviors were studied. The results showed that, because of the hydrophobicity of the silyl group, the more silane monomers in the copolymeric hydrogels the lower was the swelling ratio of the gels. The hydrophobicity of the silyl group affected the swelling mechanism, which resulted from the non‐Fickian diffusion for the gels. The copolymeric gels clearly exhibited gel transition temperatures. The copolymeric hydrogels could be applied to a drug‐release and drug‐delivery system. The delivery amount would approach a steady state after three cycle operations of delivery. The gels also showed an on–off switch behavior on drug release depending on the temperature, and the gels released more CV with the gels in a swollen state. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2523–2532, 2002
Effect of ultrasound on the physicochemical properties of organosolv lignins from wheat straw
Authors: Sun Runcang , Sun X. F. , Xu X. P. 
Published: October 2004

AbstractThe extractability and physicochemical properties of the wheat straw lignins were comparatively studied by using extraction methods with 0.5M NaOH in 60% aqueous methanol with and without application of ultrasonic irradiation. The results showed that applying sonication for 5, 10, 15, 20, 25, 30, and 35 min solubilized 67.4, 68.6, 74.4, 77.3, 77.3, 77.9, and 78.5% of the original lignin, whereas the treatment with 0.5M NaOH in 60% aqueous methanol at 60°C for 2.5 h without ultrasound assistance released 61.0% of the original lignin. The lignin preparations isolated by ultrasound‐assisted extractions showed slightly lower molecular weights, associated polysaccharides, and thermal stabilities during the initial stage of decomposition. More important, there were no significant differences in the primary structural features between the lignin preparations. Ultrasound‐assisted extractions under the alkaline organosolv extractions did not affect the overall structure of the lignin from wheat straw. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2512–2522, 2002
Bulk polymerization of styrene catalyzed by bi‐ and trifunctional cyclic initiators
Authors: Cerna J. R. , Morales G. , Eyler Gladys N. , Cañizo Adriana I. 
Published: October 2004

AbstractA study of the bulk free‐radical polymerization of styrene in the presence of the cyclic bi‐ and trifunctional initiators cyclohexanone triperoxide, diethylketone triperoxide, acetone triperoxide, cyclohexanone diperoxide, and pinacolone diperoxide is reported. When these multifunctional initiators are used for styrene polymerization at high temperatures, it is possible to produce polymers with high molecular weights and narrow polydispersities at a high reaction rate. Additionally, the former initiators are used in a mixture that shows that the molecular parameters are influenced by the initiator concentration in the initiation system, in addition to the system employed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1–11, 2002
Synthesis of graft copolymers. III. Polystyrene‐g‐poly(butyl acrylate)
Authors: Morales Graciela , Guerrero Ramiro 
Published: October 2004

AbstractPolystyrene (PS) chains functionalized with pendant 1,2‐bis(trimethylsilyloxy)tetraphenylethane (TPSE) groups are used as macroinitiators to initiate the polymerization of n‐butyl acrylate (BuA) to synthesize PS‐g‐poly(BuA) (PS‐g‐PBuA) copolymers at 130°C. The TPSE groups are known to function as initers in the polymerization of several vinyl monomers. The homolytic decomposition of TPSE results in a diphenylmethyl (DPM) radical attached to the main chain and a free DPM radical. The former is responsible for the polymerization initiation and the latter momentarily stops the growth of the growing grafts by the formation of a dormant species. Unfortunately, side reactions like the combination between growing grafts take place and the polymerization can only be controlled in a limited range of conversion. The most appropriate conditions for the synthesis of PS‐g‐PBuA are reported to present their potential use as thermoplastic elastomers with relatively controlled structures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 19–26, 2002
The new face of gross anatomy
Authors: Reidenberg Joy S. , Laitman Jeffrey T. 
Published: October 2004

AbstractThe nature of anatomy education has changed substantially over the past decade due to both a new generation of students who learn differently from those of past years and the enormity of advances in anatomical imaging and viewing. At Mount Sinai School of Medicine, our anatomy courses have been designed to meld classic dissection with the tools physicians and surgeons will use tomorrow. We introduce students to the newest technologies available for viewing the body, such as minimally invasive approaches, ultrasonography, three‐dimensional visualizations, multi‐axial computerized image reconstructions, multi‐planar magnetic resonance imaging, and plastinated prosections. Students are given a hands‐on, team‐building experience operating laparoscopes in the laboratory. A great strength of our program is the important and active participation by faculty from 15 different basic and clinical departments, including several chairs and voluntary faculty. This interdisciplinary approach brings to our students direct, one‐on‐one encounters or presentations by our finest physicians and surgeons and our core anatomy faculty. In addition, the presence of many teaching assistants drawn from upper classmen and advanced graduate students adds an additional, vibrant dimension. Our anatomy programs for medical/graduate students and postgraduates are structured around three simple principles: (1) it is a privilege to teach, (2) we enlist only passionate teachers, and (3) it is our role to instill appreciation and respect for human form. Anat Rec (New Anat) 269:81–88, 2002. © 2002 Wiley‐Liss, Inc.
Hominid cranial bone structure: A histological study of Omo 1 specimens from Ethiopia using different microscopic techniques
Authors: Bartsiokas Antonis 
Published: October 2004

AbstractThe microstructure of a hominid cranial vault has not previously been studied to determine its tissue histology, and differences in comparison with that of modern humans. We selected the parietals of Omo‐Kibish 1, regarded as one of the oldest (about 130,000 years old) anatomically modern humans, and Omo 1 (Howell), which is a very recent human (about 2,000 years old)—both from the same area of Ethiopia. A combination of macrophotography, polarizing microscopy in the incident and transmission illumination mode, and confocal laser scanning microscopy (CLSM) was employed to examine thin sections, as well as polished and unpolished block faces of unembedded bone fragments, to minimize specimen destruction as much as possible. The methods enabled remarkably detailed information on bone microstructure and remodeling to be gleaned from tiny fragments of bone. The best method for examining fossilized human bones was shown to be that of incident light microscopy, which was the least destructive while producing the most amount of information. Unless the above methods are used, bone‐filling minerals, such as calcite, can cause erroneous estimations of bone thickness, as observations with the naked eye or even a magnifying glass cannot determine the limit between the cortex and the diploe. This is particularly important for sciences such as paleoanthropology, in which, for instance, a thick cranial bone of Homo erectus may be confused with a pathological one of H. sapiens and vice versa. Cross sections of parietal bones revealed differences between Omo‐Kibish 1 and Omo 1 (Howell) in diploic histology and in the relative thickness between the cortex and diploe, with the former specimen having an H. erectus ratio despite its H. sapiens gross anatomy. Omo‐Kibish 1 may still retain some affinities with H. erectus despite its being classified as H. sapiens. Newly described histological structures, such as the reverse type II osteons, the multicanalled osteons, and the osteocytomata are presented here. A modern human skeletal anatomy does not necessarily imply a modern human cranial bone histology. The outer circumferential lamellae of cranial bones are in essence growth lines. Cranial histology of hominids may provide useful information concerning their taxonomy and life history, including such factors as growth rate, developmental stress, and diet. Anat Rec 267:52–59, 2002. © 2002 Wiley‐Liss, Inc.
Abdominal situs inversus in a Holstein calf
Authors: Fisher K.R.S. , Wilson M.S. , Partlow G.D. 
Published: October 2004

AbstractSitus inversus is a rare congenital anomaly wherein the normal, left–right organ location is inverted. The anatomical inversion (heterotaxy) is usually detected in routine radiography or other medical interventions. A 5‐month‐old Holstein heifer calf was identified as a suspected situs inversus totalis during abdominal surgery. Following surgery the calf did not gain weight. On admission to the Ontario Veterinary Hospital, it was given a routine clinical examination and a detailed cardiovascular, Doppler ultrasound examination, which appeared normal. Because of declining health and chronic bloating in the heifer, euthanasia was performed. A detailed post‐mortem dissection was carried out. No heart or lung anomalies were detected. Other thoracic organs were normal, except for a helical coil of the esophagus as it traversed the diaphragm. The rumen was located entirely on the right side of the abdomen and had a large area of adhesion to the parietal peritoneal wall. The left kidney was abnormally placed: retroperitoneal and cranial to the right. There were two spleens. The caudal vena cava was distended and twisted to the left. Thus the calf was situs inversus abdominalis. This suggests that the development of laterality in the early embryo may include both timing and positional regulation. Anat Rec 267:47–51, 2002. © 2002 Wiley‐Liss, Inc.
Comparative study of the innervation patterns of the hyobranchial musculature in three iguanian lizards: Sceloporus undulatus, Pseudotrapelus sinaitus, and Chamaeleo jacksonii
Authors: Meyers Jay J. , Herrel Anthony , Nishikawa Kiisa C. 
Published: October 2004

AbstractThe neuroanatomy and musculature of the hyobranchial system was studied in three species of iguanian lizards: Sceloporus undulatus, Pseudotrapelus sinaitus, and Chamaeleo jacksonii. The goal of this study was to describe and compare the innervation and arrangement of the hyobranchial musculature in the context of its function during tongue protrusion. A comparison of the hyobranchial innervation patterns revealed a relatively conserved innervation pattern in S. undulatus and P. sinaitus, and a modified version of this basic layout in C. jacksonii. All three species show anastomoses between sensory neurons of the trigeminal nerve and motor neurons of the hypoglossal nerve, suggesting that feedback may be important in coordinating tongue, jaw, and hyoid movements. The hyobranchial musculature of S. undulatus is very similar to that of P. sinaitus; however, there are minor differences, including the presence of an M. genioglossus internus (GGI) muscle in S. undulatus. Further differences are found mainly in functional aspects of the hyobranchial musculature, such as changes in the muscle lengths and the origins and insertions of the muscles. In C. jacksonii the hyobranchial system is comprised of largely the same components, but it has become highly modified compared to the other two species. Based on the innervation and morphological data gathered here, we propose a revision of the terminology for the hyobranchial musculature in iguanian lizards. Anat Rec 267:177–189, 2002. © 2002 Wiley‐Liss, Inc.
Spatial relation between major histocompatibility complex‐restricted antigen receptor‐bearing thymocytes and subtypes of thymic epithelial cells
Authors: Arudchelvan Yamini , Tokuda Nobuko , Sawada Tomoo , Shinozaki Fumihiko , Fukumoto Tetsuo 
Published: October 2004

AbstractR73, a monoclonal antibody that recognizes a rat T cell surface antigen of TCRαβ, was used to identify thymocytes that express major histocompatibility complex‐restricted antigen receptors, and to define the spatial relation between these receptor‐bearing thymocytes and individual thymic cortical and medullary epithelial subtypes by ultrastructural immunohistochemistry. We show that in both the cortex and medulla 1) the thymocytes that reacted with R73 antibodies exhibited three staining patterns: cytoplasmic‐only staining, simultaneous cytoplasmic and surface membrane staining, and surface membrane‐only staining; 2) the subcapsular/perivascular epithelial cells (ECs) were usually associated with thymocytes expressing perinuclear staining only; and 3) the surface membrane areas of thymocytes that expressed antigen receptors made contact with pale and intermediate ECs, but not with dark cells. These results suggest that thymic selection of major histocompatibility complex restriction and/or tolerance may occur by interaction of the receptors on maturing thymocytes with major histocompatibility complex antigens on thymic ECs in general, and on pale and intermediate subtypes in particular. Anat Rec 267:131–136, 2002. © 2002 Wiley‐Liss, Inc.
Molecular genetics of sexual development in the mushroom Coprinus cinereus
Authors: Kamada Takashi 
Published: October 2004

AbstractSexual development in the mushroom Coprinus cinereus is under the control of two mating type loci, A and B. When two haploid homokaryons with compatible alleles at both A and B loci are mated, the coordinated activities of A‐ and B‐regulated pathways lead to formation of a mycelium termed the dikaryon, in which the two nuclei from the mating partners pair in each cell without fusing. The dikaryon is a prolonged mycelial stage that can be induced to develop a multicellular structure, the mushroom, under proper environmental conditions. The two nuclei fuse in specialized cells on the mushroom and immediately undergo meiosis to complete the sexual life cycle. It has been established recently that the A genes encode two classes of homeodomain proteins while the B genes encode pheromones and their receptors. More recently, molecular genetics has been used to reveal genes that work downstream of the mating type genes to regulate dikaryon formation, mushroom morphogenesis, and meiosis. BioEssays 24:449–459, 2002. © 2002 Wiley Periodicals, Inc.
Stabilizing the regionalisation of the developing vertebrate central nervous system
Authors: Pasini Andrea , Wilkinson David G. 
Published: October 2004

AbstractDuring embryonic development, a number of tissues are patterned by their subdivision into domains with distinct regional identity. An important question is how sharp interfaces are established and maintained between adjacent domains despite the potential for scrambling due to cell intermingling during tissue growth. Two mechanisms have been found to underlie the maintenance of sharp interfaces: the specific restriction of cell mixing across boundaries, or the switching of identity of cells that cross between domains. We review the evidence for these mechanisms at distinct boundaries in the developing vertebrate central nervous system, and discuss what is known about their molecular mediators. BioEssays 24:427–438, 2002. © 2002 Wiley Periodicals, Inc.
Notching up another pathway
Authors: Brennan Keith , Gardner Philip 
Published: October 2004

AbstractThe Notch proteins play a vital role in cell fate decisions in both invertebrate and vertebrate development. Careful analysis of this role has led to a model of signalling downstream of these receptors, via the CSL (CBF1, Suppressor of Hairless, Lag‐1) family of transcription factors. There have been suggestions, however, that Notch can signal through other pathways. In the current paper, Ramain et al.1 provide compelling evidence for Notch signalling through a CSL‐independent pathway and they demonstrate that the cytoplasmic protein, Deltex, is required for this signal. In addition, they show that Wnt signalling may regulate this Deltex‐dependent signal. BioEssays 24:405–410, 2002. © 2002 Wiley Periodicals, Inc.