bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Measurement of Relative Partial Molar Enthalpy of SiO2 in SiO2–M2O (M=Li, Na, K, Cs) Binary and SiO2–CaO–Al2O3 Ternary Melts
Authors: Morishita Masao , Navrotsky Alexandra , Wilding Martin C.
Published: March 2010

The relative partial molar enthalpies, ΔH̄SiO2, of SiO2 in SiO2–M2O (M = Li, Na, K and Cs) binary and SiO2–CaO–Al2O3ternary melts were directly measured by drop‐solution calorimetry at 1465 K and 1663 K. ΔH̄SiO2 changes from exothermic to endothermic as silica content increases, confirming the tendency toward immisciblity seen from activity measurements. It is concluded that ΔH̄SiO2 is negative due to acid‐base reactions and charge‐coupled substitutions when the melt is composed of fewer Q4 and more Q3 and Q2 species, but positive due to structural strain when the melt is composed of mostly Q4 species. The ΔH̄SiO2 obtained by calorimetry is a useful measure of basicity, when comparing different alkali and alkaline earth oxides.
Oxidation Behavior of SiCN–ZrO2 Fiber Prepared from Alkoxide‐Modified Silazane
Authors: Saha Atanu , Shah Sandeep R. , Raj Rishi
Published: March 2010

The oxidation behavior of SiCN–ZrO2 fibers and SiCN at 1350°C are compared. The as‐measured parabolic rate constants for the two materials are nearly the same (15–20 × 10−18 m2/s). However, after implementing a correction for the difference in the compositions, the rate constant is 13.2 × 10−18 m2/s for the fiber, and 29.4 × 10−18 m2/s for SiCN. The lower oxidation rate of the fiber is ascribed to the lower carbon content in the fiber material.
Direct Formation and Photocatalytic Performance of Anatase (TiO2)/Silica (SiO2) Composite Nanoparticles
Authors: Hirano Masanori , Ota Keisuke
Published: March 2010

Anatase (TiO2)/silica (SiO2: 23.9–27.7 mol%) composite nanoparticles were directly synthesized from (i) the reaction of titanyl sulfate (TiOSO4) and sodium metasilicate (Na2SiO3) under mild hydrothermal conditions, (ii) the acidic precursor solutions of TiOSO4and tetraethylorthosilicate (TEOS) by thermal hydrolysis, and (iii) the metal alkoxides, i.e., tetraisopropoxide (TTIP) and TEOS, by the sol–gel method. Their photocatalytic activities were evaluated by measurements of the relative concentration of methylene blue after UV irradiation. The as‐prepared TiO2/SiO2composite nanoparticles showed far more improved photocatalytic activity than the pure anatase‐type TiO2. The composite nanoparticles formed from (i) TiOSO4and Na2SiO3as well as those from (ii) TiOSO4and TEOS showed fairly good photocatalytic activity, and it was better than that of those synthesized from (iii) the metal alkoxides, which was suggested to be due to the difference in crystallinity of the anatase.
Green Machining of a Thermoplastic Ceramic‐Ethylene Ethyl Acrylate/Isobutyl Methacrylate Compound
Authors: Koh Young‐Hag , Halloran John W.
Published: March 2010

The machinability of a thermoplastic compound that consisted of 52 vol% ceramic particles and 48 vol% thermoplastic binders was investigated. To investigate the machining mechanisms, various blends of a ductile polymer (ethylene ethyl acrylate (EEA)) and a brittle polymer (isobutyl methacrylate (IBMA)) were used as thermoplastic binders. The fraction of IBMA to EEA in the blend was increased from 0 to 50 vol%. As the IBMA content was increased, the thermoplastic compound exhibited a stiffer stress versus strain response under compression because of the brittle nature of the IBMA polymer. The machinability of the thermoplastic compound was remarkably improved with increased IBMA content because of the mitigation of the extensive deformation of the thermoplastic compound.
Preparation of a Monodispersed Suspension of Barium Titanate Nanoparticles and Electrophoretic Deposition of Thin Films
Authors: Li Juan , Wu Yong Jun , Tanaka Hidetaro , Yamamoto Takahisa , Kuwabara Makoto
Published: March 2010

A transparent and stable monodispersed suspension of nanocrystalline barium titanate was prepared by dispersing a piece of BaTiO3 gel into a mixed solvent of 2‐methoxyethanol and acethylacetone. The results of high‐resolution transmission electron microscopy (HR‐TEM) and size analyzer confirmed that the BaTiO3 nanoparticles in the suspension had an average size of ∼10 nm with a narrow size distribution. Crystal structure characterization via TEM and X‐ray diffraction indicated BaTiO3 nanocrystallites to be a perovskite cubic phase. BaTiO3 thin films of controlled thickness from 100 nm to several micrometers were electrophoretic deposited compactly on Pt/Ti/SiO2/Si substrates. The deposited thin film had uniform nanostructure with a very smooth surface.
(Sulfur, Nitrogen)‐Codoped Rutile‐Titanium Dioxide as a Visible‐Light‐Activated Photocatalyst
Authors: Liu Hongyan , Gao Lian
Published: March 2010

Many elements have been used to dope titanium dioxide (TiO2) so that it absorbs light in the visible region of the solar spectrum. We have synthesized, for the first time, (S,N)‐codoped rutile‐TiO2 photocatalyst using a hydrothermal method and subsequent nitridation under NH3 flow. The (S,N)‐codoping causes the absorption edge of TiO2 to be shifted to the longer‐wavelength region and two optical absorption bandgaps in the visible‐light region. (S,N)‐codoping has a better photocatalytic activity than S‐doping and N‐doping for degradation of methylene blue solution under visible light.
Characterization of Internal Pores in Hydrothermally Synthesized BaTiO3 Particle by Transmission Electron Microscopy
Authors: Nakano Hiromi , Urabe Kazuyori , Oikawa Tetsuo , Ikawa Hiroyuki
Published: March 2010

Hydrothermally synthesized barium titanate, BaTiO3 (commercially available), has internal pores in small particles. The three‐dimensional structures of the pores were successfully observed using transmission electron microscopy (TEM) and reconstructed by a tomography system. The behavior of the internal pore is observed in situ with increasing temperature on the thermal stage of a TEM device. We succeed in recording the movement of pores and small grains. At >1128 K, some pores move out from the particle's surface during TEM observation. The temperature roughly agrees with the temperature at which the density of BaTiO3 powder sharply increases. During observation with increasing temperature, a thin layer appeared on the particle's surface at >73 K and then disappeared at 1193 K.
Co‐firing of PZN‐PZT Flextensional Actuators
Authors: Yoon Chang‐Bun , Lee Seung‐Ho , Lee Sung‐Mi , Kim Hyoun‐Ee
Published: March 2010

Flextensional actuators composed of a piezoelectric PZN‐PZT layer and a conducting PZN‐PZT/Ag layer were fabricated. Because the newly developed PZN‐PZT was sinterable at low temperature (<900°C), silver particles could be co‐fired with the PZN‐PZT. Therefore, an electrically conducting PZN‐PZT/Ag layer was fabricated by mixing the silver particles with PZN‐PZT powder. When 30–50 wt% Ag particles were mixed with the PZN‐PZT, the resulting composites showed a high‐electrical conductivity and low‐densification mismatch with respect to the PZN‐PZT layer. The PZN‐PZT/Ag layer had approximately the same resistivity as pure silver, because of the presence of a conducting channel of dispersed silver particles in the PZN‐PZT matrix. Two‐ and three‐layered actuators were fabricated with a diameter of 20 mm and a thickness of 0.9 mm using these PZN‐PZT and PZN‐PZT/Ag composites. When an electric field was applied, the fabricated actuators bent into a convex dome shape, yielding a large axial displacement at the center.
Surface Integrity Effects on the Fracture Resistance of Electrical‐Discharge‐Machined WC–Co Cemented Carbides
Authors: Llanes Luis , Casas Begoña , Idañez Eva , Marsal Montserrat , Anglada Marc
Published: March 2010

The flexural strength evolution for two WC–16 vol% Co cemented carbides, with different mean carbide size, subjected to sequential and upgrading electrical‐discharge machining (EDM) is studied. It is compared with the fracture behavior exhibited by a reference surface finish condition, attained through conventional mechanical grinding and polishing using diamond as abrasive. Considering that rupture is related to existing defects, either introduced during sample elaboration or induced by machining, a detailed fractographic examination by scanning electron microscopy is conducted to discern fracture origins. The experimental findings indicate that the flexural strength of WC–Co hardmetals may be strongly affected by EDM, depending on the correlation existing between natural defects, as given by particular microstructural parameters, and EDM‐induced flaws. An analysis of the results using a linear–elastic fracture mechanics approach permits one to establish a clear connection between surface integrity and fracture resistance. Quantitative discrepancies between the estimated and the experimentally measured critical flaw sizes for all the EDM‐related grades are rationalized through the existence of local residual tensile stresses of considerable magnitude at the shaped surface. Release of these stresses through final mechanical and annealing treatments is pointed out as a quite effective alternative for improving the fracture behavior of WC–Co cemented carbides shaped by EDM.
Alumina Volatility in Water Vapor at Elevated Temperatures
Authors: Opila Elizabeth J. , Myers Dwight L.
Published: March 2010

The volatility of alumina in high‐temperature water vapor was determined by a weight loss technique. Sapphire coupons were exposed at temperatures between 1250° and 1500°C, water partial pressures between 0.15 and 0.68 atm in oxygen, a total pressure of 1 atm, and flowing gas velocities of 4.4 cm/s. The water vapor pressure dependence of sapphire volatility was consistent with Al(OH)3(g) formation. The enthalpy of reaction to form Al(OH)3(g) from sapphire and water vapor was determined to be 210 ± 20 kJ/mol, comparing favorably to other studies. Microstructural examination of tested sapphire coupons revealed surface rearrangement consistent with a volatilization process.
Process and Mechanical Properties of in Situ Silicon Carbide‐Nanowire‐Reinforced Chemical Vapor Infiltrated Silicon Carbide/Silicon Carbide Composite
Authors: Yang Wen , Araki Hiroshi , Kohyama Akira , Thaveethavorn Somsri , Suzuki Hiroshi , Noda Tetsuji
Published: March 2010

A SiC nanowire/Tyranno‐SA fiber‐reinforced SiC/SiC composite was fabricated via simple in situ growth of SiC nanowires directly in the fibrous preform before CVI matrix densification; the purpose of the SiC nanowires was to markedly improve strength and toughness. The nanowires consisted of single‐crystal β‐phase SiC with a uniform ∼5 nm carbon shell; the nanowires had diameters of several tens to one hundred nanometers. The volume fraction of the nanowires in the fabricated composite was ∼5%. However, the composite did not show significant increase in strength and toughness, likely because of strong bonding between the nanowires and the matrix caused by the very thin carbon coating on the nanowires. Little debonding and pullout of SiC nanowires from the matrix were observed at the fracture surfaces of the composite.
Tensile and Stress‐Rupture Behavior of SiC/SiC Minicomposite Containing Chemically Vapor Deposited Zirconia Interphase
Authors: Li Hao , Morscher Gregory N. , Lee Jinil , Lee Woo Young
Published: March 2010

The tensile and stress‐rupture behavior of SiC/SiC minicomposite containing a chemically vapor deposited (CVD) ZrO2 interphase was evaluated. Fractographic analyses showed that in situ fiber strength and minicomposite failure loads were strongly dependent on the phase contents and microstructure of the ZrO2 interphase. When the ZrO2 interphase structure possessed a weakly bonded interface within the dense ZrO2 interphase coating layer, the interphase sufficiently protected the fiber surface from processing degradation and promoted matrix crack deflection around the fibers. With this weakly bonded interphase, the stress‐rupture properties of SiC/SiC minicomposite at 950° and 1200°C appeared to be controlled by fiber rupture properties, and compared favorably to those previously measured for state‐of‐the‐art BN fiber coatings.
Conductive, Polypyrrole Coating on Mullite/Alumina Fibers for Electrophoretic Deposition of Oxide Matrices
Authors: Bao Yahua , Nicholson Patrick S.
Published: March 2010

Mullite/alumina fibers (Nextel™ 720) have been rendered conductive for electrophoretic deposition (EPD) by coating with polypyrrole (Ppy) from an aqueous solution of pyrrole (Py). The polymer coating was characterized by thermogravimetric (TG) analysis, scanning electron microscopy (SEM), and conductivity measurements. The Ppy coating thickness is ∼0.1 μm and the fiber resistance 1–2 (kΩ/cm)/fiber tow. A maximum conductivity of ∼48 S/cm was achieved from a 0.005M pyrrole solution. A Nextel 720/Al2O3 composite was synthesized using Ppy‐coated fibers as the cathode in an EPD cell. The green and sintered microstructures of the resultant composites are reported.
Development of Nanocrystalline Wear‐Resistant Y‐TZP Ceramics
Authors: Basu Bikramjit , Lee Jong‐Heun , Kim Doh‐Yeon
Published: March 2010

The present contribution reports some interesting and new results obtained while developing yttria‐stabilized tetragonal zirconia (Y‐TZP) using spark plasma sintering (SPS). The experimental results clearly showed that ZrO2‐nanoceramics with high hardness(∼14.5 GPa) can be processed at a lower sintering temperature of 1200°C in a short time (5 min). Another important result is that the newly developed Y‐TZP nanoceramics, compared with the conventional sintered TZP, exhibit better fretting wear resistance against bearing steel. The intergranular fracture and the grain pullout were observed as the major wear mechanisms of the zirconia nanoceramics.
Superhydrophobic Silica Nanocomposite Coating by a Low‐Temperature Process
Authors: Daoud Walid A. , Xin John H. , Tao Xiaoming
Published: March 2010

We successfully prepared transparent and durable superhydrophobic silica‐coating films on cotton substrates at low temperatures. The coatings were produced via cohydrolysis and polycondensation of a hexadecyltrimethoxysilane (HDTMS), tetraethoxyorthosilcate (TEOS), and 3‐glycidyloxypropyltrimethoxysilane (GPTMS) mixture. The hydrophobic properties of the nanocomposite coatings were determined using contact‐angle and water‐gain measurements. The water contact angle for the coated substrates was 141°, whereas, before coating, the contact angle was 0° because of the superhydrophilic nature of cotton. The nanocomposite coating has new applications in daily used materials, especially those with low heat resistance, such as textiles and plastics, and as an environmentally friendly water‐repellent substitute for fluorine compounds.
Sol–Gel Processing of Tetramethylammonium Silicate
Authors: Kim Deok‐Yang , Du Henry , Jr. Johnson David W. , Bhandarkar Suhas
Published: March 2010

A new sol–gel silica material based on tetramethylammonium silicate (TMAS) is reported here. Both xerogels and aerogels were produced by gelling a solution of 18.7 wt% TMAS using a series of esters. The gelation kinetics was controlled by varying the type and concentration of the ester. The supercritically dried TMAS aerogel was seen to have a larger pore size distribution with high porosity (>90%). In contrast, the conventionally dried gel showed a narrow distribution of mesopores, indicating its potential as a host matrix for protein encapsulations and catalysts.
Bioactive Calcium Phosphate Coating on Sodium Hydroxide‐Pretreated Titanium Substrate by Electrodeposition
Authors: Park Ji‐Ho , Lee Doug‐Youn , Oh Keun‐Taek , Lee Yong‐Keun , Kim Kyoung‐Nam
Published: March 2010

This study examined the characteristics of calcium phosphate coatings deposited on a NaOH‐pretreated titanium substrate by electrodeposition in a modified simulated body fluid (SBF) immediately after electrodeposition as well as after the coatings had been immersed in the SBF for 5 d in order to determine the effects of a NaOH pretreatment on the bioactive coating prior to electrodeposition. The results showed that a dense and uniform coating that consisted of brushite and hydroxyapatite had formed on the NaOH‐pretreated titanium substrate by electrodeposition. This coating had transformed to a bonelike apatite during immersion in the SBF. This was attributed to the increased surface area of the modified titanium formed after the NaOH treatment as well as the Na+ ions released from that surface. Therefore, a NaOH pretreatment is recommended as an effective method for preparing a bioactive calcium phosphate coating by electrodeposition.
Improved Estimation of Weibull Parameters with the Linear Regression Method
Authors: Wu Dongfang , Lu Guanzhong , Jiang Hong , Li Yongdan
Published: March 2010

Monte Carlo simulations were used to search for the optimal probability estimator for estimating Weibull parameters with the linear regression method. Compared with commonly used probability estimators, the optimal one obtained gives a more accurate estimation of the Weibull modulus and the same estimation precision of the scale parameter. It is also concluded that the maximum likelihood method results in the highest precision, however, less conservative than the linear regression method.
Mechanochemical Synthesis of Ammonium Hexafluorogallate
Authors: Lu Jinfeng , Zhang Qiwu , Wang Jun , Saito Fumio
Published: March 2010

Mechanochemical reaction between ammonium fluoride (NH4F) and gallium fluoride trihydrate (GaF3·3H2O) at a ratio of 3:1 is conducted by grinding the mixture at room temperature using a planetrary ball mill. A single phase of ammonium hexafluorogallate ((NH4)3GaF6) is obtained as a product of the reaction. Other alkali hexafluorogallates (K3GaF6, Na3GaF6, and Li3GaF6) also can be synthesized by grinding constituent components (AF and GaF3·3H2O) under proper grinding conditions. A reaction mechanism related to the dissolution of alkali fluorides in water is suggested.
Inward Cationic Diffusion and Percolation Transition in Glass–Ceramics
Authors: Smedskjaer Morten M. , Yue Yuanzheng , Mørup Steen
Published: March 2010

We show the quantitative correlation between the degree of crystallization and the cationic diffusion extent in iron‐containing diopside glass–ceramics at the glass transition temperature. We find a critical degree of crystallization, above which the diffusion extent sharply drops with the degree of crystallization. Below the critical value, the diffusion extent decreases only slightly with the degree of crystallization. No cationic diffusion is observed in the fully crystalline materials. The critical value might be associated with a percolation transition from an interconnected to a disconnected glass phase.
Symbolic Versus Associative Learning
Authors: Hummel John E.
Published: March 2010

Ramscar and colleagues (2010, this volume) describe the “feature‐label‐order” (FLO) effect on category learning and characterize it as a constraint on symbolic learning. I argue that FLO is neither a constraint on symbolic learning in the sense of “learning elements of a symbol system” (instead, it is an effect on nonsymbolic, association learning) nor is it, more than any other constraint on category learning, a constraint on symbolic learning in the sense of “solving the symbol grounding problem.”
Gatekeepers: A Missed Opportunity for Safe Transport
Authors: Schneider Sandra M. , Cobaugh Daniel J. , Leahey Neil F.
Published: March 2010

Abstract. Objective: To assess whether contact with a health care provider or gatekeeper increases the use of an ambulance for patients with acute chest pain. Methods: A convenience sample of adults ≥:40 years of age presenting with a chief complaint of chest pain were interviewed by trained personnel regarding transport used to come to the ED. The study was performed at the ED of an urban university hospital. Patients with hemodynamic instability and those receiving thrombolytics or emergency angio‐plasty were excluded. Patients were asked about access to a primary health care provider and contact with a provider regarding this ED visit, including instructions given for transportation. Results: Of the 450 interviewed patients, 42% arrived by ambulance. Those who had contact with a health care provider prior to the ED visit were less likely to come by ambulance than those without contact, 31% vs 51% (p < 0.001). Of the patients who had cardiac enzymes obtained to work up for their chest pain, 34% with health provider contact vs 57% without health provider contact arrived by ambulance (p < 0.001). Of those with acute myocardial infarction, 30% with health provider contact vs 66% without health provider contact came by a mbulance (p < 0.03). Patients who recalled transport instructions from their providers tended to follow those instructions. The majority of patients who recalled no specific transport instructions arrived by personal automobile. Conclusion: Of patients presenting to an ED for evaluation of chest pain, those who made contact with a health care provider were less likely to arrive via ambulance.
Parenteral vs Oral Antibiotics in the Prevention of Serious Bacterial Infections in Children with Streptococcus pneumoniae Occult Bacteremia: A Meta‐analysis
Authors: Rothrock Steven G. , Green Steven m. , Harper Marvin B. , Clark Mark C. , McIlmail Daniel P. , Bachur Richard
Published: March 2010

Abstract. Objective: To determine whether parenteral antibiotics are superior to oral antibiotics in preventing serious bacterial infections in children with Streptococcus pneumoniae occult bacteremia. Methods: Using the MEDLINE database, the English language literature was searched for all publications concerning bacteremia, fever, or Streptococcus pneumoniae from 1966 to January 1, 1997. All nondupli‐cative studies with a series of children with S. pneumoniae occult bacteremia having both orally treated and parenterally treated groups were reviewed. Children were excluded from individual studies if at the time of their initial evaluation they were immuno‐compromised, had a serious bacterial infection, underwent a lumbar puncture, or did not receive antibiotics. Results: Only 4 studies met study criteria. From these studies, 511 total cases of S. pneumoniae occult bacteremia were identified. Ten of 290 (3.4%) in the oral group and 5 of 221 (2.3%) in the parenteral antibiotic group developed serious bacterial infections (pooled p‐value = 0.467, pooled OR = 1.48; 95% CI, 0.5–4.3). Two patients in the oral group (0.7%) and 2 patients in the parenteral group (0.9%) developed meningitis (pooled p‐value = 0.699, pooled OR = 0.67; 95% CI, 0.1–5.1). Conclusion: The rates of serious bacterial infections and meningitis did not differ between children who were treated with oral and parenteral antibiotics. The extremely low rate of complications observed in both groups suggests no clinically significant difference between therapies. A study with > 7,500 bacteremic children (or >300,000 febrile children) would be needed to have 80% power to prove parenteral antibiotics are superior to oral antibiotics in preventing serious bacterial infections.
Detection of Alcohol Use in Adolescent Patients in the Emergency Department
Authors: Barnett Nancy P. , Spirito Anthony , Colby Suzanne M. , Vallee Jeffrey A. , Woolard Robert , Lewander William , Monti Peter M.
Published: March 2010

Abstract. Objectives: To examine 3 methods of detecting alcohol use among adolescent patients visiting a Level‐1 regional trauma center. Methods: Part 1 was a retrospective review of laboratory records and (13‐ to 19‐year‐old) patient medical records over the 1‐year period from August 1993 to July 1994. Part 2 was a review of ICD‐9 discharge diagnoses for the same age range during the same 1‐year period. Part 3 involved prospective saliva alcohol testing of injured patients aged 13—17 years old. Results: Part 1: A total of 522 blood tests were conducted and 160 (30.6%) were positive for alcohol. More than one‐third of the alcohol‐positive sample had alcohol ingestion as the only reason for their visits, i.e., they were uninjured. The alcohol‐positive group was more likely to be male and older. Part 2: A total of 99 alcohol‐related discharge diagnoses were given to adolescent patients. Alcohol abuse was the most common diagnosis. With the 2 methods of detection combined, 186 patients were identified. Part 3: A total of 119 saliva alcohol tests were conducted. One patient tested positive but had been identified while in triage as having used alcohol. Conclusion: In this study population, approximately one‐third of adolescent patients tested for alcohol as part of routine clinical care were alcohol‐positive but were not necessarily given an alcohol‐related diagnosis. Thus, studies determining rates of alcohol‐positive adolescents treated in EDs should use multiple methods of detection. Universal testing does not appear to be warranted for all injured adolescent patients.
The Tokyo Subway Sarin Attack: Disaster Management, Part 2: Hospital Response*
Authors: Okumura Tetsu , Suzuki Kouichiro , Fukuda Atsuhiro , Kohama Akitsugu , Takasu Nobukatsu , Ishimatsu Shinichi , Hinohara Shigeaki
Published: March 2010

Abstract. The Tokyo subway sarin attack was the second documented incident of nerve gas poisoning in Japan. The authors report how St. Luke's Hospital dealt with this disaster from the viewpoint of disaster management. Recommendations derived from the experience include the following: Each hospital in Japan should prepare an emergent decontamination area and have available chemical‐resistant suits and masks. Ventilation in the ED and main treatment areas should be well planned at the time a hospital is designed. Hospital disaster planning must include guidance in mass casualties, an emergency staff call‐up system, and an efficient emergency medical chart system. Hospitals should establish an information network during routine practice so that it can be called upon at the time of a disaster. The long‐term effects of sarin should be monitored, with such investigation ideally organized and integrated by the Japanese government.
The Tokyo Subway Sarin Attack: Disaster Management, Part 3: National and International Responses
Authors: Okumura Tetsu , Suzuki Kouichiro , Fukuda Atsuhiro , Kohama Akitsugu , Takasu Nobukatsu , Ishimatsu Shinichi , Hinohara Shigeaki
Published: March 2010

Abstract. The authors report the national and international responses to the disaster produced by the Tokyo subway sarin attack. From a worldwide historical perspective, there had never been such a large‐scale disaster caused by nerve gas during peacetime. Therefore, this event should be studied from various viewpoints in cooperation with members of the international community. To this end, the Japanese government should help coordinate a large‐scale and detailed investigation of the Tokyo subway sarin attack, including the long‐term effects of sarin. The authors also recommend that the Japanese Self Defense Forces should be used more effectively in large‐scale disasters. The system of direct control of disaster management by the Japanese government could be useful in a large‐scale disaster.
End‐tidal Carbon Dioxide Monitoring in Emergency Medicine, Part 2: Clinical Applications
Authors: Ward Kevin R. , Yealy Donald M.
Published: March 2010

Abstract. End‐tidal carbon dioxide (PetCO2) monitoring is becoming more common in both the ED and the out‐of‐hospital setting. Its main use has been as an aid when confirming endotracheal intubation. Other uses in the ED include monitoring CPR efforts and monitoring the ventilatory and hemodynamic status of intubated and nonintubated patients. In addition, future uses may include using PetCO2 as an adjunct when monitoring the status of asthma treatment, when making the diagnosis of pulmonary embolism, and when measuring cardiac output nonin‐vasively. This article reviews these specific uses of PetCO2 monitoring in emergency medicine.
Bedside Emergency Department Ultrasonography plus Radiography of the Kidneys, Ureters, and Bladder vs Intravenous Pyelography in the Evaluation of Suspected Ureteral Colic
Authors: Henderson Sean O. , Hoffner Richard J. , Aragona Jodi L. , Groth Diane E. , Esekogwu Victor I. , Chan Dennis
Published: March 2010

Abstract. Objective: To determine the role of bedside renal ultrasonography (US) and plain radiography of the kidneys, ureters, and bladder (KUB) as the initial investigative modality for those patients presenting to the ED with unilateral flank pain and he‐maturia. The hypothesis was that the renal US + KUB may obviate the need for emergent IV pyelography (IVP) in a majority of patients. Methods: Prospective study over an 8‐month period of all consecutive adult patients between the ages of 18 and 65 years presenting with unilateral flank pain and he‐maturia to the ED at LAC + USC Medical Center. Patients received KUB followed by a 500‐mL bolus of normal saline. Bedside US was then performed by emergency physicians (EPs). Hydronephrosis of the kidney was graded as mild, moderate, or severe. All patients then underwent IVP. The results of the bedside US + KUB were then compared with those of IVP (the criterion standard). Results: Of a total of 139 eligible patients, 108 were enrolled. The combination of US and KUB correctly identified pathology consistent with nephroureterolithiasis with a sensitivity of 97.1% (95% CI = 93.1–100%) when compared with IVP. The KUB + US results were falsely positive in 16 patients, resulting in a specificity of 58.9% (95% CI = 43.5–74.3%). The positive predictive value of the combined modality was 80.7%, the negative predictive value was 92.0%, and the overall accuracy was 83.3%. Conclusion: The bedside US + KUB has a high sensitivity and can be performed rapidly at the bedside by the EP when compared with IVP. This combined modality is an effective screening tool in the initial evaluation of ureteral colic.
Effect of 50 Milliliters of 50% Dextrose in Water Administration on the Blood Sugar of Euglycemic Volunteers
Authors: Balentine Jerry R. , Gaeta Theodore J. , Kessler Diana , Bagiella Emilia , Lee Teddy
Published: March 2010

Abstract. Objective: To evaluate the effect of administration of 1 ampule of 50% dextrose in water solution (D50W) on serum glucose levels in healthy adult volunteers, the authors set out to determine whether a pre‐D60W serum glucose level can be predicted from the ED sample. Methods: This was a prospective, interventional study conducted from the ED of an urban, university‐affiliated hospital. All subjects were healthy employee volunteers between 25 and 40 years of age. Baseline serum glucose levels were determined and all subjects were given an IV bolus of 25 grams of 50% dextrose solution. The main outcome measures were post‐D50W serum glucose levels (observed) at 5 predetermined time intervals (5 min, 15 min, 30 min, 1 hr, and 2 hr). An expected change in serum glucose was calculated using the volume of distribution formula for glucose. Results: Twenty‐five volunteers (17 males and 8 females) participated in the study. The mean baseline serum glucose was 82.3 ± 13.5 mg/dL. The mean post‐infusion levels were: 244.4 ± 44.6 mg/dL (5 min), 145.8 ± 52.3 mg/dL (15 min), 88.1 ± 28.8 mg/dL (30 min), 77.6 ± 13.6 mg/dL (60 min), and 83.2 ± 11.4 mg/dL (120 min). Using a mixed‐effect regression model, statistically significant increases in serum glucose levels were found at 5 minutes (p < 0.001) and 15 minutes (p < 00001) following administration of D50W. There was a return to baseline serum glucose by 30 minutes. The expected change based on the volume of distribution formula (53.7 ± 34.9) did not correlate with the observed changes at any measured time interval. Conclusion: Without pre‐intervention blood drawing by emergency medical services, it is not possible to accurately predict pre‐D50W serum glucose levels based on post‐D50W glucose levels. The diagnosis of hypoglycemia as the etiology of altered mental status must therefore remain a diagnosis of exclusion. In addition, the return of serum glucose to baseline after 30 minutes suggests the duration of the effect of 1 ampule of D50W. Frequent re‐evaluation of the serum glucose levels of suspected or proven hypoglycemic patients after administration of D50W should be considered.
A Comparison of Multimedia and Standard Advanced Cardiac Life Support Learning
Authors: Christenson Jim , Parrish Kevin , Barabe Sandy , Noseworthy Robert , Williams Tony , Geddes Ross , Chalmers Andrew
Published: March 2010

Abstract. Objectives: To compare student performance after Multimedia ACLS Learning System (MM) education compared with that after standard (ST) ACLS education. Methods: Final‐year medical students were divided into 2 groups based on convenience scheduling and given ACLS instruction either in a standard format or with the MM course. The sizes of the small groups and the times in small‐group instruction were identical. All students were evaluated with the same 50‐item multiple‐choice written examination, a structured evaluation immediately after the management of a mock cardiac arrest, and a second structured evaluation of the same mock arrest (videotaped) by an instructor blinded to the education method. Students were assigned a mark from 1 to 5 in each of 4 domains: assessment, immediate priorities, continual assessment, and leadership. Results: 75 students took the MM and 38 took the ST course. The mean ± SD mark for the multiple‐choice test was 89.3 ± 4.9% (MM) vs 89.3 ± 4.8% (ST); the on‐site mock arrest evaluation mark (20 maximum) was 14.1 ± 2.5 (MM) vs 14.1 ± 2.0 (ST); and the blinded mock arrest evaluation was 13.1 ± 2.9 (MM) vs 14.4 ± 2.9 (ST) (p = 0.024). 1/75 (MM) vs 0/38 (ST) did not successfully complete the on‐site mock arrest evaluation. More students in the MM group (46% vs 25%) required multiple attempts to successfully complete the mock arrest evaluation (p < 0.02). Conclusion: In medical students with no previous ACLS training, structured access to the multimedia ACLS Learning System provides immediate educational outcomes similar to those of a standard ACLS course. Multimedia computer‐interactive learning should be enhanced with a short period of hands‐on practice.
Automated External Defibrillators: Skill Maintenance Using Computer‐assisted Learning
Authors: Jerin John M. , Ansell Bruce A. , Larsen Mary Pat , Cummins Richard O.
Published: March 2010

Abstract. Objective: To determine whether computer‐assisted learning (CAL) can maintain the automated external defibrillation (AED) skills of emergency medical technicians (EMTs).

Methods: The authors conducted a 1‐year prospective comparison of an AED‐skill training software program, running on desktop computers, with traditional instructor‐led training. The subjects were experienced EMT‐Ds (EMT‐defibrillation), already trained in automated defibrillation (n= 105) employed as full‐time professional EMT‐D/firefighters. Two of the 3 groups (groups A and C) in the study were assigned to use the CAL program for 6 months. The third group (group B) remained on the normal, instructor‐led training regimen. Pre‐ and poststudy skill levels were measured using a skills performance test.

Results: A secular trend of improved mean treatment scores was observed across all 3 groups [mean rise of 0.49 point (p = 0.01), repeated‐measures analysis of variance]. There were no differences between training groups in the increase in performance scores (p = 0.3). The 1‐time cost of supplying the CAL program to the 105 EMT‐Ds was $1,575, significantly less than the $3,240‐per‐year cost associated with instructor‐led training. Conclusions: The authors observed satisfactory AED skill maintenance for experienced EMT‐Ds using CAL to replace 2 of 4 quarterly instructor‐led skills reviews. CAL has cost and convenience advantages over instructor‐based skill maintenance and is an acceptable alternative.
The Short‐term Outcome of Hypoglycemic Diabetic Patients Who Refuse Ambulance Transport after Out‐of‐hospital Therapy
Authors: Mechem C. Crawford , Kreshak Allyson A. , Barger Jennifer , Shofer Frances S.
Published: March 2010

Abstract. Objective: lb determine the short‐term medical outcome of hypoglycemic insulin‐dependent diabetic patients who refuse transport after out‐of‐hospital therapy and return to baseline mental status. Methods: Prospective, descriptive, short‐term medical outcome data for adult patients were collected between May 1996 and December 1996. Paramedics responding to the aid of hypoglycemic insulin‐dependent diabetic patients who refused transport after administration of dextrose solution (D50W) contacted a medical command physician at the University of Pennsylvania. The patients' medical histories, names, addresses, and telephone numbers were recorded. Three days after their hypoglycemic episodes, these patients were contacted by telephone by a registered nurse to determine their medical conditions. Results: Of 132 patients enrolled in the study, 103 (78%) could be contacted by telephone follow‐up. Ninety‐four (91%) of these patients had no recurrence of symptoms. Nine patients (9%) had recurrence of hypoglycemia and recontacted 911. Eight of these (8%) were transported to a hospital via ambulance and 3 (3%) were admitted, 1 (1%) for a cancer‐related illness and 2 (2%) for hypoglycemia, 1 of whom died (1%). The remaining patient refused transport a second time after being treated, despite having the risks of refusal explained to him by a medical command physician. Conclusions: The practice of treating and releasing most hypoglycemic insulin‐dependent diabetic patients who return to normal mental status after D50W administration appears in general to be safe. Patients should be advised of the risks of recurrent hypoglycemia.
Behavioral Risk Factors in Emergency Department Patients: A Multisite Survey
Authors: Lowenstein Steven R. , Koziol‐McLain Jane , Thompson Michael , Bernstein Edward , Greenberg Karen , Gerson Lowell W. , Buczynsky Paul , Blanda Michelle
Published: March 2010

Abstract. Background: Many people rely on EDs for routine health care. Often, however, screening and counseling for health risks are not provided. Objective: To determine prevalence rates of chronic disease and injury risk factors and access to routine health care in a random sample of ED patients in 3 cities. Methods: A prospective survey was conducted at 3 hospital EDs in Akron, OH, Boston, MA, and Denver, CO. A modified version of the national Behavioral Risk Factor Surveillance Survey was administered by trained researchers to a convenience sample of non‐critically ill patients during randomly selected shifts. Results: Of 1,143 eligible patients, 923 (81%) agreed to participate. Their mean age was 39 (range = 17–96) years. Most were female (58%), white (60%), and unmarried (68%). Thirty‐eight percent had no access to primary care. Injury‐prone behaviors were prevalent: 53% of the respondents did not wear seat belts regularly; 15% had no working smoke detector; 3% kept loaded, unlocked handguns in their homes; 11% had attempted suicide; 23% had a positive CAGE screen for alcoholism; 3% had operated a motor vehicle in the preceding month while alcohol‐intoxicated; and 11% had ridden in an automobile with an intoxicated driver. Cancer and chronic disease risks were also common: 48% smoked; 16% had not received a blood pressure check in the preceding year; and 4% reported unsafe sexual practices. Among women aged >50 years, 42% had not received a Pap test in the prior 2 years and 14% had never had mammography. Many prevalence rates and access to care varied among the 3 sites. However, for most risk factors, prevalence rates did not differ in patients with and without access to primary health care. Conclusions: ED patients have high rates of injury and chronic disease risks, and many have no other source of routine health care. Research is needed to determine whether ED‐based programs, designed to reduce injury and chronic disease risks, are feasible and cost‐effective.
Acute Renal Failure Associated with Suspected Amanita smithiana Mushroom Ingestions: A Case Series
Authors: Warden Craig R. , Benjamin Denis R.
Published: March 2010

Abstract. Mushroom poisoning leading to acute renal failure is extremely rare in North America. Cortinarius species and Amanita smithiana both can cause acute renal failure and inhabit the Pacific northwest. This article describes 4 patients who presented in acute renal failure and who ingested mushrooms described as resembling A. smithiana. Two patients (a 74‐year‐old Korean couple) described eating mushrooms with an approximately 6 × 0.5‐inch stipe with a white cap, 1.25‐1.5 inches in diameter. The other 2 patients (a 55‐year‐old male and a 30‐year‐old female) also described a white‐capped mushroom. All believed they were eating the matsutake (Tricho‐loma magnivalere) mushroom, which can be mistaken for A. smithiana. Onset of gastrointestinal symptoms ranged from 20 minutes to 12 hours, and presentation in acute renal failure ranged from 4 to 6 days postingestion (initial BUN and creatinine were 72–91 mg/dL and 12–13.9 mg/dL, respectively). One patient had underlying mild renal insufficiency and one had hypertension that was under control, while the others had no risk factors for renal disease. None had any other explanation for the episode of acute renal failure. All underwent acute hemodialysis for at least several weeks, eventually returning to baseline renal function.
The Jehovah's Witness Blood Refusal Card: Ethical and Medicolegal Considerations for Emergency Physicians
Authors: Migden Douglas R. , Braen G. Richard
Published: March 2010

Abstract. Jehovah's Witnesses are members of a Christian group that does not allow blood transfusion. It is a general practice for adult Witnesses to carry on their person a wallet‐sized advance directive card refusing blood. The blood refusal card directs that no blood is to be given to the owner under any circumstance, even if physicians believe transfusion will be lifesaving. Although the card claims to refuse blood on a religious basis, it also states that there are various dangers associated with blood. The possibility that in an emergency the dangers of blood may be relatively small, as compared with the likelihood of death due to exsanguination without blood, is not noted on the card. Emergency physicians should look for evidence of an informed refusal when evaluating these documents. Advance directives regarding life and death decisions should be subject to scrutiny and not be automatically accepted at face value. A good‐faith decision to transfuse the unconscious adult Jehovah's Witness, in emergent need of blood, is justified if the patient does not have a blood refusal advance directive that is informed and otherwise survives a high level of scrutiny. The ethical and medicolegal considerations upon which this thesis is based are discussed.
Honoring Jehovah's Witnesses' Advance Directives in ‘ Emergencies: A Response to Drs. Migden and Braen
Authors: Ridley Donald T.
Published: March 2010

Abstract. Jehovah's Witnesses refuse blood transfusions out of obedience to the Bible's command to all Christians to abstain from blood. The Witnesses take this scriptural injunction seriously and, of their own initiative, execute advance medical directive cards to communicate their refusal to medical personnel in the event of their incapacity. In portraying the Witnesses' refusal of blood as the uninformed result of their subjugation by the Watchtower Society, Migden and Braen1 distort the facts about Jehovah's Witnesses, the basis for their refusal of blood, and their use of the blood refusal card. Further, not only does Migden and Braen's analysis subordinate patient values to professional preference in all cases, but the heightened scrutiny protocol they propose is useless because it cannot possibly be implemented in the hypothetical they posit. Finally, their legal analysis is not well founded and practitioners who choose to follow it will do so at their peril.
Refusal of Out‐of‐hospital Medical Care: Effect of Medical‐control Physician Assertiveness on Transport Rate
Authors: Burstein Jonathan L. , Hollander Judd E. , Delagi Robert , Gold Matthew , Henry Mark C. , Alicandro Jeanne M.
Published: March 2010

Objective: Previous studies have shown that contacting an on‐line medical‐control physician increases the transport rate of patients who attempt to refuse medical assistance. The authors studied the physician‐patient interaction to determine the type of interaction that was more likely to result in patient transport.

Methods: A prospective, observational study of patient‐initiated refusals of medical assistance (RMAs) was performed in a suburban volunteer emergency medical services (EMS) system, with 12 receiving hospitals county‐wide. Medical‐control contact was required for all patient‐initiated RMAs. Consecutive patients who attempted out‐of‐hospital RMA over a 3‐month period were monitored. Structured data instruments were completed by the medical‐control operator and medical‐control physician for all patients who attempted RMA. Data collected included patient demographics and contact information, scene characteristics, history and physical examination data, length of time of interaction, and the physician's assessment of the need for transport and the patient's capacity to refuse transport. The operator and physician independently graded the physician's assertiveness in talking to the patient on a continuous 10‐point scale.

Results: There were 130 patients who attempted RMA; 69 (53%) refused transport even after discussion with the medical‐control physician, while 61 (47%) were transported to a hospital. The patients who were transported did not differ from those not transported with respect to age, chief complaint, vital signs, or presence of police on scene. Using the operators' independent assessments, the physicians were more assertive when they graded the patient as being more ill (needs transport, 8.8; may need transport, 7.7; doesn't need transport, 4.1; p < 0.01). When the physicians were more assertive, the patients were more likely to agree to transport (assertiveness >8, 81% transport; assertiveness <8, 19% transport; p < 0.01).

Conclusions: Contact with a medical‐control physician appears to markedly improve the transport rate for patients who initially attempt to refuse out‐of‐hospital medical care. This is especially so when physicians are more assertive in recommending transport.
Effects of Hyperbaric Oxygen on Neurologic Outcome for Cerebral Ischemia in Rats
Authors: Roos Joel A. , Jackson‐Friedman Cathy , Lyden Patrick
Published: March 2010

Objective:To evaluate the effect of hyperbaric oxygen (HBO) therapy on neurologic outcome (assessed by the quantal bioassay approach) following acute focal cerebral ischemia in rats.

Methods:Two separate experimental trials were conducted. Trial 1, a nonblinded experiment, used 38 rats. Trial 2, a blinded experiment, used 59 rats. Focal cerebral ischemia was induced with a surgically placed intraluminal occlusion of the left middle cerebral artery; subsequent removal allowed reperfusion. Arterial occlusion times were varied from 5 to 90 minutes in trial 1, and from 3 to 45 minutes in trial 2. The control groups were maintained at ambient pressure for the duration of each trial. The trial 1 treatment group received a single 30‐minute HBO treatment at 2.0 atmospheres absolute (ATA) on the initial day of ischemia. The trial 2 treatment group received 30‐minute HBO treatments at 2.0 ATA daily for 4 consecutive days. The animals underwent daily 5‐point neurologic examinations. A computerized quantal bioassay was used to determine the ET50—the occlusion time required to cause a neurologic abnormality in half of the animals. The control and treatment ET50values were compared in each trial using a 2‐tailed t‐test. An increased ET50for the treatment vs the control group implied a beneficial effect of HBO; a decrease, the opposite. The study had a power of 80% to detect a difference of 11.4 minutes in the ET50for a 2‐sided α= 0.05.

Results:For trial 1: the HBO ET50was 18.1 ± 21.9 minutes and the control ET50was 22.8 ± 25.0 minutes (p > 0.2). For trial 2: the HBO ET50was 9.49 ± 17.4 minutes and the control ET50was 14.9 ± 14.2 minutes (p < 0.2).

Conclusion:HBO therapy showed no apparent benefit in a rat model as a treatment modality for acute cerebral ischemia with reperfusion.