bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of Emergency Medicine Program Directors
Authors: Beeson Michael S. , Gerson Lowell W. , Weigand John V. , Jwayyed Sharhabeel , Kuhn Gloria J. 
Published: January 2006

Objectives:
To characterize emergency medicine (EM) program directors (PDs) and compare the data, where possible, with those from other related published studies.
Methods:
An online survey was e‐mailed in 2002 to all EM PDs of programs that were approved by the Accreditation Council of Graduate Medical Education. The survey included questions concerning demographics, work hours, support staff, potential problems and solutions, salary and expenses, and satisfaction.
Results:
One hundred nine of 124 (88%) PDs (69.7% university, 27.5% community, and 2.8% military) completed the survey; 85.3% were male. Mean age was 43.6 years (95% confidence interval [CI] = 42.6 to 44.7 yr). The mean time as a PD was 5.7 years (95% CI = 4.9 to 6.5 yr), with 56% serving five years or less. The mean time expected to remain as PD is an additional 6.0 years (95% CI = 5.2 to 6.8). A 1995 study noted that 50% of EM PDs had been in the position for less than three years, and 68% anticipated continuing in their position for less than five years. On a scale of 1 to 10 (with 10 as highest), the mean satisfaction with the position of PD was 8.0 (95% CI = 7.2 to 8.3). Those PDs who stated that the previous PD had mentored them planned to stay a mean of 2.0 years longer than did those who were not mentored (95% CI of difference of means = 0.53 to 3.53). Sixty‐five percent of PDs had served previously as an associate PD. Most PDs (92%) have an associate or assistant PD, with 54% reporting one; 25%, two; and 9%, three associate or assistant PDs. A 1995 study noted that 62% had an associate PD. Ninety‐two percent have a program coordinator, and 35% stated that they have both a residency secretary and a program coordinator. Program directors worked a median of 195 hours per month: clinical, 75 hours; scholarly activity, 20 hours; administrative, 80 hours; and teaching and residency conferences, 20 hours; compared with a median total hours of 220 previously reported. Lack of adequate time to do the job required, career needs interfering with family needs, and lack of adequate faculty help with residency matters were identified as the most important problems (means of 3.5 [95% CI = 3.2 to 3.7], 3.4 [95% CI = 3.2 to 3.6], and 3.1 [95% CI = 2.9 to 3.3], respectively, on a scale of 1 to 5, with 5 as maximum). This study identified multiple resources that were found to be useful by >50% of PDs, including national meetings, lectures, advice from others, and self‐study.
Conclusions:
Emergency medicine PDs generally are very satisfied with the position of PD, perhaps because of increased support and resources. Although PD turnover remains an issue, PDs intend to remain in the position for a longer period of time than noted before this study. This may reflect the overall satisfaction with the position as well as the increased resources and support now available to the PD. PDs have greater satisfaction if they have been mentored for the position.
Cognitive Performance Following Modafinil versus Placebo in Sleep‐deprived Emergency Physicians: A Double‐blind Randomized Crossover Study
Authors: Gill Michelle , Haerich Paul , Westcott Kelli , Godenick Kristen L. , Tucker Jennifer A. 
Published: January 2006

Objectives:
Modafinil has recently been approved for the treatment of shift work sleep disorder, making it potentially available for shift‐working emergency physicians. The authors' objectives were to determine whether modafinil improved cognitive performance of emergency physicians following overnight shifts and to record symptoms and subjective evaluations of the effect of modafinil on the participants.
Methods:
This was a randomized, double‐blind, placebo‐controlled crossover study that followed CONSORT guidelines. Participants were assigned to one of two study groups, with study sessions occurring at least seven weeks apart, and received either modafinil or placebo depending on their random allocation. Testing after night shifts included a coding task and an AX version of the Continuous Performance Task, both of which test cognitive function. Participants also completed visual analog scales for three subjective outcomes, and symptoms were elicited.
Results:
Modafinil facilitated performance on long interstimulus‐interval AX trials (F [1, 23] = 6.65, p = 0.1) and marginally reduced errors on AY trials in the Continuous Performance Task (F [1, 23] = 3.59, p = 0.07), suggesting facilitation of sustained attention, cognitive control, and working memory. Additionally, modafinil, compared with placebo, facilitated performance on the coding task at the first session. Subjective data from visual analog scales confirmed that modafinil increased perceived alertness during the simulated patient care sessions but worsened sleep onset when opportunities for sleep arose.
Conclusions:
Modafinil increased certain aspects of cognitive function and subjectively improved participants' ability to attend post–night‐shift didactic sessions but made it more difficult for participants to fall asleep when opportunities for sleep arose.
Lipid Rafts Mediate Ultraviolet Light‐induced Fas Aggregation in M624 Melanoma Cells
Authors: Elyassaki Walid , Wu Shiyong 
Published: January 2006

ABSTRACTUltraviolet light (UV) induces aggregation of Fas‐receptor through a Fas‐ligand‐independent pathway. However, the mechanism of ultraviolet light‐induced Fas‐receptor aggregation is not known. In this report, we show that lipid rafts mediate ultraviolet light‐induced aggregation of Fas. Our data show that UV induces a redistribution of Fas‐receptor in a 25–5% Optiprep continuous gradient. The amount of Fas‐receptor is significantly increased in a gradient fraction that contain lipid rafts and is associated with an increase of FADD and caspase‐8. Our data also show that the active dimeric form of caspase‐8 (p44/p41) is increased in the lipid raft fraction. In addition, our data show that cholesterol, a major component of lipid rafts, is significantly reduced in only the lipid raft fractions after UV‐irradiation. However, ceramide, another major lipid raft component, is increased evenly in all gradient fractions after UV‐irradiation. These results suggest that UV alters the composition of major lipid raft components, which leads to the recruitment of Fas‐receptor and FADD, with subsequent activation of caspase‐8. Based on our results, we propose a novel mechanism by which UV induces apoptosis through a membrane lipid raft‐mediated signaling pathway.
Cover Picture: A Two‐Dimensional Porphyrin‐Based Porous Network Featuring Communicating Cavities for the Templated Complexation of Fullerenes (Adv. Mater. 3/2006)
Authors: Spillmann H. , Kiebele A. , Stöhr M. , Jung T. A. , Bonifazi D. , Cheng F. , Diederich F. 
Published: January 2006

AbstractA 2D porous network has been realized by self‐assembly of porphyrin modules on a silver surface, as reported by Diederich and co‐workers on p. 275. The so‐formed pores are able to host single fullerene molecules and mediate long‐range interactions between such carbon guests, resulting in the formation of large supramolecular chains and islands. The cover shows a scanning tunnelling microscopy image of several single C60 molecules (large green protrusions) hosted in the 2D porous network. As indicated by the molecular model, each pore is formed by the symmetric arrangement of three porphyrin molecules and the fullerene guest is located exactly in the center of the cavity.
Inside Front Cover: Electronic Transport through Electron‐Doped Metal Phthalocyanine Materials (Adv. Mater. 3/2006)
Authors: Craciun M. F. , Rogge S. , den Boer M.‐J. L. , Margadonna S. , Prassides K. , Iwasa Y. , Morpurgo A. F. 
Published: January 2006

AbstractTransport measurements for different electron‐doped metal–phthalocyanine (MPc) materials are reported by Morpurgo and co‐workers on p. 320. It is experimentally demonstrated that for these doped MPc materials, increasing the doping level results first in a metallic state and, subsequently, in the re‐entrance of an insulating state. The artist's impression on the inside cover shows an MPc film situated between two electrodes and exposed to a flux of alkali atoms in vacuum. The alkali atoms intercalate and donate electrons to the molecular material.
One step synthesis and rapid ring‐opening polymerization of macrocyclic (arylene thioether ketone) oligomers
Authors: Yan H. , Li X. H. , Wang S. J. , Meng Y. Z. 
Published: January 2006

AbstractWell‐crystal macrocyclic (arylene thioether ketone) oligomers were synthesized under high dilution condition by the reaction of Na2S with bis(4‐fluoro‐phenyl)‐methanone in 1‐methyl‐pyrrolidone (NMP). The oligomers were fully characterized by Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectra (MALDI‐TOF‐MS), high‐pressure liquid chromatography (HPLC), gel permeation chromatography (GPC), 1H NMR, 13C‐NMR, and differential scanning calorimetry (DSC). According to DSC studies, uncatalyzed and rapid ring‐opening polymerization (ROP) of the oligomers took place instantly when they were heated to melting point. Extracted by dichloro‐methane, the obtained polymer neither loses any weight nor dissolves in boiling 1‐chloro‐ naphthalene. These facts indicated that there are no residual oligomers within the resultant polymer. The as‐prepared oligomers could be potentially used as high‐temperature hot‐melt adhesive at a high temperature > 350°C, and matrices for high‐performance composites and nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 161–166, 2006
Properties of fullerene‐containing natural rubber
Authors: Jurkowska B. , Jurkowski B. , Kamrowski P. , Pesetskii S. S. , Koval V. N. , Pinchuk L. S. , Olkhov Y. A. 
Published: January 2006

AbstractAddition of fullerene in concentration between 0.065 and 0.75 phr increases Schob elasticity, hardness, and modulus of NR‐based rubber. There is no substantial influence of fullerene on Tg, tan δ, and G‐modulus all evaluated by DMA at twisting within a temperature range −150 to −50°C (glassy state). At temperatures between 0 and 150°C (rubbery state) it is different, namely an increase in modulus and some changes in the slope of segments in G(T) curves were observed. It could be resulted from additional strong physical junctions of the rubber network. This suggests the growth of degradation energies of the branching junctions and related rise in the aging resistance as concentration of fullerene increases. Simultaneously, it could be expected some reduction of tire temperature at service. Because of this, introduction of fullerene could be reasonable for tread rubbers in case of reduction of its price. Permittivity and dielectric loss angle are correlated with fullerene concentration. Compounding technology when fullerene dispersed within carbon black is mixed with raw rubber on available machines could be easily implemented in the industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 390–398, 2006
Studies on LDPE—Cyanoethylated lignocellulosics blends using epoxy functionalized LDPE as compatibilizer
Authors: Sailaja R. R. N. 
Published: January 2006

AbstractRubberwood flour and cellulose have been plasticized by cyanoethylation and then blended with low‐density polyethylene (LDPE). A small quantity of epoxy functionalized polyethylene i.e., polyethylene‐co‐glycidyl methacrylate (PEGMA) has been added to further enhance the mechanical properties. The mechanical properties were measured according to the standard ASTM methods. SEM analysis was performed for both fractured and unfractured blend specimens. The mechanical properties were improved by the addition of PEGMA compatibilizer. LDPE blends with cyanoethylated wood flour (CYWF) showed higher tensile strength and modulus than cyanoethylated cellulose CYC‐LDPE blends. However CYC‐LDPE blends exhibited higher relative elongation at break values as compared with the former. The TGA analysis showed lowering of thermal stability as the filler content is increased and degradation temperature of LDPE is shifted slightly to lower temperature. DSC analysis showed loss of crystallinity for the LDPE phase as the filler content is increased for both types of blends. Dielectric properties of the blends were similar to LDPE, but were lowered on adding PEGMA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 219–237, 2006
Destabilization mechanism of polyethylene‐modified bitumen
Authors: Pérez‐Lepe A. , Martínez‐Boza F. J. , Attané P. , Gallegos C. 
Published: January 2006

AbstractPolymer‐modified binders are widely used for pavement construction. Among different polymers used to modify bitumen, polyolefins have shown to impart beneficial effects on the bitumen, especially to prevent some of the pavement shortcomings at high temperatures, such as rutting. The phase separation problems of these polymers from the bitumen may affect the final properties of the pavement. The determination of the polymer phase destabilization mechanism and rate are crucial to defer or delay the polymer separation from the matrix. With this aim, several HDPE‐modified binders were manufactured by using a high‐shear mixing device. The binders were stored in tubes at temperatures as high as 180°C. During the storage, the unstable polymer phase creamed up to the surface. The destabilization process was followed by means of optical microscopy observations through time, as the separation process proceeded. The segregation of the polymer phase is shown to be preceded by a coalescence mechanism. Enhanced mechanical properties have been obtained by HDPE modification. However, such binders may not be efficient for the pavement application, since phase separation may occur during the application of the binder on the road. Functionalized reactive polymers are envisaged to hinder the separation problems in bituminous binders. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 260–267, 2006
Surface grafting polymerization of N‐vinyl‐2‐pyrrolidone onto a poly(ethylene terephthalate) nonwoven by plasma pretreatment and its antibacterial activities
Authors: Chen Ko‐Shao , Ku Yuan‐An , Lin Hong‐Ru , Yan Tsong‐Rong , Sheu Dey‐Chyi , Chen Tim‐Mo 
Published: January 2006

AbstractThe objective of this research was the surface grafting polymerization of biocompatible monomer N‐vinyl‐2‐pyrrolidone (NVP) onto a plasma‐treated nonwoven poly(ethylene terephthalate) (PET) substrate with ultraviolet (UV)‐induced methods. The effects of various parameters, such as the monomer concentration, reaction time, initiator (ammonium peroxodisulfate) concentration, and crosslinking agent (N,N′‐methylene bisacrylamide) concentration, on the grafting percentage were studied. The grafting efficiency of the modified nonwoven PET surfaces reached a maximum at 50 min of UV irradiation and with a 30 wt % aqueous NVP solution. After the plasma activation and/or grafting, the hydrophobic surface of the nonwoven was modified into a hydrophilic surface. NVP was successfully grafted onto nonwoven PET surfaces. The surface wettability showed that the water absorption of NVP‐grafted nonwoven PET (NVP‐g‐nonwoven PET) increased with increasing grafting time. NVP‐g‐nonwoven PET was verified by Fourier transform infrared spectra and scanning electron microscopy measurements. An antibacterial assessment using an anti‐Staphylococcus aureus test indicated that S. aureus was restrained from growing in NVP‐g‐nonwoven PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 803–809, 2006
Effect of polymerization time on the molecular weight and molecular weight distribution of polypropylene
Authors: Abedi S. , Hosseinzadeh M. , Kazemzadeh M. A. , Daftari‐Besheli M. 
Published: January 2006

AbstractThe influence of the polymerization time on the molecular weight (Mw, Mn, Mp, and Mz), molecular weight distribution (MWD) and relative MWD of polypropylene (PP) in the propylene polymerization with a Mg(OEt)2/DIBP/TiCl4/PTES/AlEt3 catalyst system in the slurry phase has been studied by using gel permeation chromatography (GPC), where Mg(OEt)2, DIBP (diisobutyl phthalate), TiCl4, PTES (phenyl triethoxy silane), and triethyl aluminum (TEA) are support, internal donor, catalyst, external donor, and cocatalyst, respectively. It has been found that the increase of the polymerization time increases the molecular weight and MWD of PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 368–371, 2006
Synthesis of poly(ferrocenylsilanes) with different molecular weight and their electrochemical behavior
Authors: Wang Jian Jun , Wang Li , Wang Xue Jie , Chen Tao , Chen Ying 
Published: January 2006

AbstractA series of poly(ferrocenylsilanes) (PFS) with different molecular weight have been prepared via the thermal ring‐opening polymerization of the corresponding monomers. The electrochemical behavior of poly(ferrocenyldimethylsilane) (PFDMS) and poly(ferrocenylmethylphenylsilane) (PFMPS) in solutions were investigated by cyclic voltammetry (CV). It was found that PFS could be adsorbed and electrodeposited on the Pt electrode surface, and the electroactive multilayer films formed on the Pt electrode surface influenced the shape of the voltammogram. The redox potential varied with the molecular weight slightly, and ΔE1/2 became smaller with the increase in molecular weight. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 473–477, 2006
Determination of dynamic mechanical properties of engineering thermoplastics at wide frequency range using Havriliak–Negami model
Authors: Setua D. K. , Gupta Y. N. , Kumar S. , Awasthi R. , Mall A. , Sekhar K. 
Published: January 2006

AbstractUsing Havriliak–Negami (HN) model of time–temperature superposition, dynamic mechanical properties for two thermorheologically simple engineering thermoplastics, viz., polyether ether ketone (PEEK) and polycarbonate (PC) were determined. Calculations have been made with respect to (i) temperature‐independent HN parameters from dynamic mechanical analysis (DMA) and (ii) activation energies of the deformation processes involved. Viscoelastic properties, over a wide frequency range, were predicted from the HN model, which were further correlated with the experimentally determined quantities and chemical structure of the polymers. The mathematical calculations were done using Matlab® software. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 677–683, 2006
Polystyrene nanocomposite materials—Preparation, mechanical, electrical and thermal properties, and morphology
Authors: Ma Chen‐Chi M. , Chen Yi‐Jie , Kuan Hsu‐Chiang 
Published: January 2006

AbstractThis work prepared polystyrene resin nanocomposites with antistatic properties, by melt‐blending polystyrene with nanoscale zinc oxide. The effect of nanoscale zinc oxide on the electrical and physical characteristics of polystyrene nanocomposites was investigated. Two kinds of nanoscale powders, spherical zinc oxide (s‐ZnO) and zinc oxide whisker (w‐ZnO), were selected. The coupling agents, vinyltriethoxysilane and phenyltriethoxysilane, were utilized to improve the compatibility between nanopowders and polystyrene resin. Adding spherical zinc oxide and zinc oxide whisker improved the antistatic characteristic of materials. The surface resistivities of s‐ZnO and w‐ZnO nanocomposite were significantly reduced, by modification with vinyltriethoxysilane and phenyltriethoxysilane. Adding zinc oxide nanopowder increased the flexural modulus and reduces flexural strength. Silane coupling agent improved the flexural properties of nanocomposite. The glass transition temperature and thermal degradation temperature of zinc oxide/polystyrene nanocomposite increased with ZnO content. Treatment with silane increased the glass transition temperature and thermal degradation temperature of composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 508–515, 2006
Selectivity of shear rate on chains in polymer combination reaction
Authors: Liu Mengge , Yu Wei , Zhou Chixing 
Published: January 2006

AbstractThe combination reaction of linear low density polyethylene initiated by Dicumyl peroxide at elevated temperature was investigated under different steady shear rates. Gel‐permeation chromatography was used to determine the molecular weight distributions, and time–molecular weight superposition method was used to analyze the viscosity curves. The results showed that lower (or higher) shear rate increased the reaction possibility of shorter (or longer) chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 839–842, 2006
Alkyd–epoxy blends as multipurpose coatings
Authors: Dutta N. , Karak N. , Dolui S. K. 
Published: January 2006

AbstractThe alkyd resins of three different compositions based on nahar seed oil (Mesua ferrea), phthalic anhydride, and maleic anhydride were synthesized by an alcoholysis method. These alkyd resins were blended with a commercially available epoxy resin (Araldite 250, Ciba Geigy, Mumbai, India) separately to study the performance of the blends as coatings. The morphology of the blends was studied with scanning electron microscopy. The drying time, gloss, flexibility, pencil hardness, adhesion, pressure test, and chemical resistance under different conditions were measured for this purpose. The thermal characteristics of the blends were also investigated by thermogravimetric analysis. The studies showed better performance of the blends with respect to the drying time, hardness, flexibility, gloss, pressure test, thermal stability, and chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 516–521, 2006
Thermotropic liquid crystallinity, thermal decomposition behavior, and aggregated structure of poly(propylene carbonate)/ethyl cellulose blends
Authors: Zhang Zhihao , Zhang Huiliang , Zhang Qingxin , Zhou Qinghai , Zhang Hongfang , Mo Zhishen , Zhao Xiaojiang , Wang Xianhong 
Published: January 2006

AbstractMaleic anhydride end capped poly(propylene carbonate) (PPC‐MA) was blended with ethyl cellulose (EC) by casting from dichloromethane solutions. The thermotropic liquid crystallinity, thermal decomposition behavior, and aggregated structure were investigated by differential scanning calorimetry (DSC), thermogravimetry (TGA), and wide angle X‐ray diffraction (WAXD). DSC exhibits thermotropic liquid crystallinity in the rich EC composition range. TGA shows that thermal decomposition temperatures were elevated upon interfusing EC into PPC‐MA. WAXD corroborates that EC and PPC‐MA/EC blend films cast from dilute dichloromethane solution possessed cholesteric liquid crystalline structure in the rich EC composition range, and that dilution of PPC‐MA with EC increased the dimension of noncrystalline region, leading to a more ordered packed structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 584–592, 2006
Mechanical, thermal, and morphological properties of bismaleimide/unsaturated polyester copolymers
Authors: Li Ying , Feng Lei , Zhang Liu‐Cheng 
Published: January 2006

AbstractAn unsaturated polyester (UP) resin was modified by the addition of a thermosetting bismaleimide (BMD) as a second coreactive monomer. The copolymers were characterized in terms of mechanical, thermal, and morphological properties by tensile, bend, and impact testing; thermogravimetric analysis; heat deforming temperature analysis; dynamic mechanical analysis; and scanning electron microscopy. In addition, Fourier transform infrared spectroscopy of modified resin indicated that crosslinking networks were formed between BMD and UP. The properties of the modified resins were compared with those of unmodified resins. The results indicate that the addition of BMD not only improved the thermal decomposition temperature and heat deforming temperature but also caused small changes in the mechanical properties. The effect of the construct of BMD and the reactions among BMD, UP, and styrene were analyzed. The results show that BMD has great potential to improve the properties of UP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 593–598, 2006