bluuebunny/crossref_metadata_2025_split huggingface dataset:
Treatment from birth of nonketotic hyperglycinemia due to a novel GLDC mutation
Authors: Korman Stanley H. , Wexler Isaiah D. , Gutman Alisa , Rolland Marie‐Odile , Kanno Junko , Kure Shigeo 
Published: January 2006

AbstractObjectiveTo determine whether the devastating outcome of neonatal‐onset glycine encephalopathy (NKH) could be improved by instituting treatment immediately at birth rather than after symptoms are already well established.MethodsA newborn with NKH diagnosed prenatally following the neonatal death of a previous affected sibling was treated from birth with oral sodium benzoate (250mg/kg/day) and the NMDA receptor antagonist ketamine (15mg/kg/day) immediately after sampling cord blood and cerebrospinal fluid (CSF) for glycine determination. Glycine cleavage system (CGS) activity was determined in placental tissue. Mutation analysis was performed by sequencing all GLDC, GCSH and AMT exons.ResultsCSF glycine (99 μmol/L, reference 3.8–8.0) was already markedly elevated at birth. GCS activity in placental tissue was severely reduced (2.6% of controls). A novel homozygous GLDC c.482A→G(Y161C) missense mutation was identified. Neonatal hypotonia and apnea did not occur but the long‐term outcome was poor, with intractable seizures and severe psychomotor retardation. This contrasts with the favorable outcome with early treatment in variant NKH with mild GCS deficiency (Ann Neuol 2004;56:139–143).InterpretationProspective treatment with this regimen can favorably modify the early neonatal course of severe NKH but does not prevent the poor long‐term outcome, suggesting glycine‐induced prenatal injury and/or ongoing postnatal damage. Ann Neurol 2006
Serine Octamers: Cluster Formation, Reactions, and Implications for Biomolecule Homochirality
Authors: Nanita Sergio C. , Cooks R. Graham 
Published: January 2006

AbstractThe emergence of homochirality continues to be one of the most challenging topics associated with the origin of life. One possible scenario is that aggregates of amino acids might have been involved in a sequence of chemical events that led to chiral biomolecules in self‐replicating systems, that is, to homochirogenesis. Serine is the amino acid of principal interest, since it forms “magic‐number” ionic clusters composed of eight amino acid units, and the clusters have a remarkable preference for homochirality. These serine octamer clusters (Ser8) can be generated under simulated prebiotic conditions and react selectively with other biomolecules. These observations led to the hypothesis that serine reactions were responsible for the first chiral selection in nature which was then passed through chemical reactions to other amino acids, saccharides, and peptides. This Review evaluates the chemistry of Ser8 clusters and the experimental evidence that supports their possible role in homochirogenesis.
Apoptolidin: Induction of Apoptosis by a Natural Product
Authors: Daniel Peter T. , Koert Ulrich , Schuppan Julia 
Published: January 2006

AbstractApoptolidin is a natural product that selectively induces apoptosis in several cancer cell lines. Apoptosis, programmed cell death, is a biological key pathway for regulating homeostasis and morphogenesis. Apoptotic misregulations are connected with several diseases, in particular cancer. The extrinsic way to apoptosis leads through death ligands and death receptors to the activiation of the caspase cascade, which results in proteolytic degradation of the cell architecture. The intrinsic pathway transmits signals of internal cellular damage to the mitochondrion, which loses its structural integrity, and forms an apoptosome that initiates the caspase cascade. Compounds which regulate apoptosis are of high medical significance. Many natural products regulate apoptotic pathways, and apoptolidin is one of them. The known synthetic routes to apoptolidin are described and compared in this Review. Selected further natural products which regulate apoptosis are introduced briefly.
Study of the flexural modulus of natural fiber/polypropylene composites by injection molding
Authors: Shibata Shinichi , Cao Yong , Fukumoto Isao 
Published: January 2006

AbstractEffect of fiber compression on flexural modulus of the natural fiber composites was examined. The kenaf, bagasse, and polypropylene were mixed into pellets, and composites were fabricated by injection molding. To predict flexural modulus of the composites, the Young's modulus of kenaf and bagasse fiber were measured. Using the obtained Young's modulus, the flexural modulus of the composites was predicted by Cox's model that incorporates the effect of fiber compression. It was found that those fibers with high Young's modulus were more compressed than that with low Young's modulus. Moreover, the distribution of fiber length and orientation in the composites were also investigated. To calculate the orientation factor for the prediction model, the distribution function of fiber orientation was determined to a triangular function. The flexural modulus of the composites increased with increase of volume fraction. The predicted values were in good agreement with the experimental values. Furthermore, it was revealed by SEM that the porous structure of the natural fibers was compressed. The fiber compression ratio (3.6) in bagasse was higher than that in kenaf (1.4) due to the difference in porous structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 911–917, 2006
Synthesis and characterization of suspension terpolymer of N‐cyclohexylmaleimide, methyl methacrylate, and styrene
Authors: Yang Liting , Sun Donghai 
Published: January 2006

AbstractN‐cyclohexylmaleimide (ChMI) and styrene (St) were polymerized with methyl methacrylate (MMA) at different St feed content by suspension polymerization method. The glass transition temperatures (Tg) of the terpolymers were detected by torsional braid analysis (TBA). Two transition peaks in TBA curves of the terpolymers with a high St content illustrated that these terpolymers have a heterogeneous chain structure and the phase separation occurred. The lower transition temperature, Tg1, was assigned to the random St‐MMA components, and the higher transition temperature, Tg2, was assigned to the St‐ChMI units‐rich segments. Thermogravimetric analyses (TGA) revealed that all the terpolymers showed a two‐step degradation process. The tensile strength of the terpolymers decrease with increasing St content while the impact strength tended to increase slightly. The rheological behavior of the terpolymers was also detected. The result illustrated that the terpolymers showed rheological behavior similar to that of pseudoplastic liquid. The apparent shear viscosity decreased with the increasing of St content. All terpolymers have a higher value of flow n than the poly(MMA‐co‐ChMI). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 918–922, 2006
Attaining a controlled graded distribution of particles in polymerizing fluid for functionally graded materials
Authors: Hashmi S. A. R. 
Published: January 2006

AbstractThe precise control on concentration profile of dispersion in functionally graded material (FGM) is essential for obtaining a desired material. A suitable simulation of parameters and an appropriate model that describes the motion of particles in the fluid can predict various aspects those are needed to produce FGM, by gravity sedimentation or centrifugation technique. Simulation was conducted to observe the changes in concentration profile, while using the following equations applicable to polymerizing fluid, and to determine the terminal velocities (Vm) of particles; Vm = {D2(ρs − ρl)g*(1 − ϕs)4.65}/(18μ0e) for gravity sedimentation and Vm = {D2(ρs − ρl)rω2(1 − ϕs)4.65}/(18μ0 e) for centrifugation, where D is the diameter of the spherical particle, ρs the density of solid particles, ρl the density of fluid, μ the viscosity of fluid, g* the acceleration due to gravity, ϕs is the volume fraction of particles, and tc is the elapsed time of curing of thermosetting resin. b is a constant, r is the radius, and ω is the angular velocity. This simulation demonstrates that the time of centrifugation/sedimentation, particle size, distribution of particle size, and centrifugal/gravitational forces can be effectively utilized to attain a desired concentration profile in graded materials. Simulation also revealed that there exist the possibility of two graded profiles, namely low concentration profile and high concentration profile, in one sample of graded material, made either by centrifugation or sedimentation. Low concentration profile is more sensitive to particle size distribution as compared to high concentration profile. The present simulation method is also sensitive to concentration‐measuring methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Surface properties of block and graft polystyrene–polydimethylsiloxane copolymers
Authors: Wu Ningjing , Huang Likan , Zheng Anna , Xiao Huining 
Published: January 2006

AbstractThe surface compositions of a series of polystyrene‐b‐polydimethylsiloxane (PS‐b‐PDMS) and polystyrene‐g‐polydimethylsiloxane (PS‐g‐PDMS) copolymers were investigated using ATR‐FTIR and XPS technique. The results showed that enrichment of PDMS soft segments occurred on the surface of the block copolymers as well as on that of graft copolymers. And the magnitude order of the enrichment was as follows: PS‐b‐PDMS > PS‐g‐PDMS, which was attributed to the facilitating of the movement of the PDMS segments in PS‐b‐PDMS copolymer. Meanwhile, the solvent type and the contact medium had influence on the accumulation of PDMS on the surfaces. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Preparation of organic–inorganic nanocomposites with core‐shell structure by inorganic powders
Authors: Naderi Nader , Sharifi‐Sanjani Naser , Khayyat‐Naderi Baharak , Faridi‐Majidi Reza 
Published: January 2006

AbstractOrganic–inorganic nanocomposites with core‐shell structure were prepared in two steps. In the first step, the latex particles in the semibatch emulsion polymerization of butyl methacrylate (BMA), in the presence of methacrylic acid (MAA), were prepared. Small amounts of acrylic acid incorporated into the latex to have better interaction between the surface of particles and inorganic phase. MAA also increased the latex stability and decreased the amount of coagulum. In the second step, the core‐shell structures were prepared by coating the latex particles with three types of inorganic powders. Pectin coated precipitated calcium carbonate, alumina, and silica. The examinations show that pectin‐coated calcium carbonate has the best response than other types of calcium carbonate. Alumina was the second type of inorganic powder that was used for coating the core particles. Silicagel and fumed silica (Aerosil) were used for coating by silica. Scanning electron microscopy and transmission electron microscopy showed the particle morphology and the core‐shell structure, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Synthesis and properties of polyimide (containing naphthalene) nanocomposites with organo‐modified montmorillonites
Authors: Tsay Sun‐Yuan , Chen Bor‐Kuan , Chen C.‐P. 
Published: January 2006

Abstract2,7‐Bis(4‐aminophenoxy) naphthalene (BAPN), a naphthalene‐containing diamine, was synthesized and polymerized with a 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) to obtain a polyimide (PI) via thermal imidization. To enhance the thermal and mechanical properties of the polymer, PI–Montmorillonite (MMT) nanocomposites were prepared from a DMAc solution of poly(amic acid) and a DMAc dispersion of MMT, which were organo‐modified with various amounts of n‐dodecylamine (DOA) or cetylpyridium chloride (CPC). FTIR, XRD, and TEM (transmission electron microscopy) were used to verify the incorporation of the modifying agents into the clay structure and the intercalation of the organoclay into the PI matrix. Results demonstrated that the introduction of a small amount of MMT (up to 5%) led to the improvement in thermal stability and mechanical properties of PI. The decomposition temperature of 5% weight loss (Td,5%) in N2 was increased by 46 and 36°C in comparison with pristine PI for the organoclay content of 5% with DOA and CPC, respectively. The nanocomposites were simultaneously strengthened and toughened. The dielectric constant, CTE, and water absorption were decreased. However, at higher organoclay contents (5–10%), these properties were reduced because the organoclay was poorly dispersed and resulted in aggregate formation. The effects of different organo‐modifiers on the properties of PI–MMT nanocomposite were also studied; the results showed that DOA was comparable with CPC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Mechanical properties and thermal stability of rice husk ash filled epoxy foams
Authors: Stefani P. M. , Cyras V. , Tejeira Barchi A. , Vazquez A. 
Published: January 2006

AbstractMechanical properties and thermal stability of epoxy foams filled with white and black rice husk ash were studied. Epoxy foams were prepared from a commercial system and filled with different amounts of both the ashes (0, 6.8, 12.8, 18.0, and 22.7 wt %). The incorporation of both the ashes modified the final morphology of the foam, decreasing the average cell size and increasing the number of cells per volume unit. For all filler percentages used, the specific modulus and strength results showed that the white ash is more effective as reinforcing agent than the black ash. The initial degradation temperature was not affected by the content and type of ash used as the filler. The integral procedure decomposition temperature, weight loss, and char residue results were related to the ash type and atmosphere used in the thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Poly(methacrylic acid)‐bound dihydroxybenzene units: Redox polymers
Authors: Moulay Saād , Mehdaoui Razika 
Published: January 2006

AbstractPoly(methacrylic acid) (PMAA) was functionalized with a hydroquinone/catechol under the reaction conditions of Minisci. Optimum conditions for maximum functionalization (52%) were found to be as follows: [benzoquinone]/[PMAA] ratio, 0.75; reaction time, 3 h; temperature, 75°C; and a nitrogen atmosphere. Redox properties of hydroquinone/catechol‐modified PMAA (PMAA‐HQ) were evaluated by their midpotentials potentiometrically estimated to be 898 mV at 20°C. At 35°C, a two‐stage oxidation was observed with a midpotential of 1000 mV. These midpotentials were found to be higher than those of hydroquinone, catechol, and a 1 : 1 hydroquinone‐catechol mixture, under the same conditions of potentiometric titration. Under the modification reaction conditions, the modified PMAA underwent severe degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 954–961, 2006
Submicron copper‐low‐density polyethylene conducting composites: Structural, electrical, and percolation threshold
Authors: Alvarez M. P. , Poblete V. H. , Pilleux M. E. , Fuenzalida V. M. 
Published: January 2006

AbstractCopper‐embedded low‐density polyethylene (LDPE) composites were fabricated using different copper concentrations in the polymer matrix. The copper particles were spherical with a mean particle size between 200 and 300 nm. All the samples were compacted under pressure and melted. The LDPE matrix was analyzed using gel permeation chromatography (GPC) and it did not evidence degradation of the LDPE matrix. The microstructure of the composites was examined with scanning electron microscopy. The electrical conductivity was measured as a function of the copper content, and the composite fabricated with a 10 vol % copper presented a conductivity 15 orders of magnitude higher than that of pure LDPE. The enhancement in conductivity can be explained by means of segregated percolation path theory and the experimental results are in agreement with the theoretical law. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Synthesis and characterization of new blue‐photoluminescent copolymer derived from bisphenol A
Authors: Jaballah N. , Trad H. , Majdoub M. , Jouini M. , Roussel J. , Fave J. L. 
Published: January 2006

AbstractA new copolymer with short alternating conjugated and nonconjugated blocks, derived from bisphenol A (BPAEt2‐PPV) containing separated phenylenevinylene (PV) units has been synthesized by Wittig condensation. The copolymer is fully soluble in common organic solvents and has a number‐average molecular weight of 3200 with a polydispersity index of 1.53. The structure of the polymer was confirmed by 1H NMR, 13C NMR, FTIR and Raman spectroscopic analysis. Thermogravimetric analysis and differential scanning calorimetry indicate that BPAEt2‐PPV is stable up to 400°C in air and displays a glass transition temperature of 107°C. The fluorescence spectrum of the polymer film shows an emission in the blue region (428, 456, and 488 nm). The band‐gap energy, estimated from the edge absorption of the film, is about 2.9 eV. A single‐layer diode device of the configuration ITO/BPAEt2‐PPV/Al has been fabricated and has a relatively low turn‐on voltage of 3.7 V. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Influence of the process on phase separation induced by radical copolymerization of styrene and divinylbenzene in the presence of reactive polyurethane network precursors
Authors: Chenal Jean‐Marc , Colombini Didier , Widmaier Jean‐Michel 
Published: January 2006

AbstractInterpenetrating polymer systems based on crosslinked polyurethane (PU) and polystyrene (PS) were prepared at room temperature by a one‐shot (in situ) method, starting from an initial homogeneous mixture of reagents via noninterfering mechanisms. Both polymerizations were performed either simultaneously or one after the other. True simultaneity at every stages of the process is not possible. Despite the difference in refractive index of the components, hazy or optically clear films were obtained, thus indicating various levels of phase separation, also confirmed by glass transition temperature (Tg) measurements. The results suggest that controlling the chemistry and process (crosslink density, composition, and time sequence of events) of in situ interpenetrating network formation will give various morphologies, and hence properties, ranging from microphase separated materials to larger macrophase separated materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
NMR imaging and differential scanning calorimetry study on drying of pine, birch, and reed pulps and their mixtures
Authors: Heikkinen Sari , Alvila Leila , Pakkanen Tuula T. , Saari Terhi , Pakarinen Pekka 
Published: January 2006

AbstractDrying, water fractions, and water distribution were investigated for pine, birch, and reed pulps and pine–birch, pine–reed, and pine–birch–reed pulp mixtures. Gravimetrically determined drying times showed that the drying rates of the pulps decreased at two to four inflection points. Characterizations of the dried pulps by differential scanning calorimetry (DSC) showed a faster removal of free water than freezing and nonfreezing bound waters; all decreased simultaneously, however. DSC also revealed the critical water contents at which the free water and freezing bound water disappeared. The gravimetrically determined inflection points of the drying curves corresponded with the critical points determined by DSC. NMR line widths and images produced by1H‐NMR imaging revealed the nature and regions of the pulp drying. The constant growth rate of the NMR line widths with decreasing water content appeared to change at two inflection points, which fell approximately in the same water content regions as the inflection points of the drying curves. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 937–945, 2006
Chemical synthesis and characterization of polyaniline nanofiber doped with gadolinium chloride
Authors: Zhang Shuling , Kan Suqing , Kan Jinqing 
Published: January 2006

AbstractGadolinium Chloride (GdCl3) has been employed as dopant to synthesize conductive polyaniline (PANI) using chemical method. The resulting products were characterized using infrared spectroscopy, UV–vis spectra, scanning electron microscope, differential thermal analyzer, and X‐ray diffraction. It was found that Gd3+ can interact with PANI chains and induce changes on the properties of PANI. The addition of GdCl3 could greatly increase electrical conductivity and crystalline degree of PANI. Changes in UV–vis and FTIR spectra show that there exists interaction between gadolinium ions and PANI chain. The effect of different proportions of ammonium persulfate on the properties of PANI was also discussed. When the molar ratios of GdCl3 to aniline is 2 : 1 and ammonium persulfate to aniline is 1 : 1, the more uniform and regular PANI nanofiber can be prepared. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 946–953, 2006
A modified vacation model M[x]/G/1 system
Authors: Ke Jau‐Chuan , Chu Yunn‐Kuang 
Published: January 2006

AbstractThis paper studies the operating characteristics of an M[x]/G/1 queueing system under a modified vacation policy, where the server leaves for a vacation as soon as the system is empty. The server takes at most J vacations repeatedly until at least one customer is found waiting in the queue when the server returns from a vacation. We derive the system size distribution at different points in time, as well as the waiting time distribution in the queue. Further, we derive some important characteristics including the expected length of the busy period and idle period. This shows that the results generalize those of the multiple vacation policy and the single vacation policy M[x]/G/1 queueing system. Finally, a cost model is developed to determine the optimum of J at a minimum cost. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of circadian variation on outcomes in emergency acute anterior myocardial infarction percutaneous coronary intervention
Authors: Assali Abid R. , Brosh David , Vaknin‐Assa Hana , Fuchs Shmuel , Teplitsky Igal , Sela Ofer , Kornowski Ran 
Published: January 2006

AbstractObjectives: We investigated the impact of primary coronary angioplasty performed during night and compared to the impact of that performed during day‐time on outcomes of patients with acute ST elevation anterior wall myocardial infarction (AMI). Methods: We prospectively followed 273 consecutive patients of whom 160 (58.6%) were treated during day time (8:00 a.m. to 6 p.m.) and 113 (41.4%) were treated “off hours”/at night (6 p.m. to 8 a.m.). Baseline demographics, angiographic factors, and clinical outcomes (death, recurrent AMI, and need for repeat revascularization) were compared between the groups. Results: Baseline clinical characteristics were similar between the two groups. Unadjusted mortality at one‐month was significantly higher among patients who were treated during night compared with those treated at day‐time (9.7% vs. 3.1% P = 0.03), as was adverse cardiac event rate (15.9% vs. 6.9%; P = 0.02). Multiple logistic regression analysis adjusted for the CADILLAC risk score demonstrated that this score, which includes baseline LVEF, renal failure, Killip class, final TIMI flow, age>65 years, anemia, and the number of coronary vessel diseases, is a significant predictor of one‐month mortality, while the effect of time of treatment was borderline (night vs. day; odds ratio 2.7; 95% confidence interval, 0.8–9.4; P = 0.095). Conclusions: The results of this study indicate that patients with anterior myocardial infarction treated during night time have worse unadjusted short‐term clinical outcomes despite no delay from onset of symptoms to actual treatment. Larger studies are needed in order to identify potential contributors to this phenomenon. © 2006 Wiley‐Liss, Inc.
Readily Tunable and Bifunctional L‐Prolinamide Derivatives: Design and Application in the Direct Enantioselective Aldol Reactions.
Authors: Chen Jia‐Rong , Lu Hai‐Hua , Li Xin‐Yong , Cheng Lin , Wan Jian , Xiao Wen‐Jing 
Published: January 2006

AbstractFor Abstract see ChemInform Abstract in Full Text.