bluuebunny/crossref_metadata_2025 huggingface dataset:
A Spatial–Temporal Stochastic Simulation of Fire Outbreaks Following Earthquake Based on GIS
Authors: Zhao S. J. , Xiong L. Y. , Ren A. Z.
Published: June 2006

Post-earthquake fire is a dangerous secondary disaster following an earthquake, which causes severe life losses and property destruction. Similar to other natural disasters, fire outbreak following an earthquake carries its own spatial and temporal characters. In order to explore these characters, we analyzed in detail the fires caused by the Hanshin earthquake in Japan (1995). We identified the key spatial–temporal characters of the fire outbreak following an earthquake. Using this analysis methodology, we further collected and organized the records of post-earthquake fires that have occurred in the 20th century in USA, Japan, and China, and modeled fire outbreaks following an earthquake by employing a regression analysis method. Considering the stochastic characters of post-earthquake fires, we proposed a random Poisson event and Weibull distribution model in constructing the spatial–temporal probability distribution of fire outbreaks following an earthquake in urban districts. In addition, we propose a geographical information system (GIS) based stochastic simulation schema to predict the spatial–temporal process of fire outbreaks following future earthquakes. Finally, we applied our models to simulate the fire outbreaks in Xiamen city after an assumed earthquake of a similar magnitude as the Hanshin earthquake. Our simulation result not only exhibits the spatial–temporal characters of fire outbreaks following an earthquake, but also supplies valuable decision-making information to the planning of Xiamen city's seismic prevention and mitigation.
Contour Laser – Laser-Transmission Welding of Glass Reinforced Nylon 6
Authors: Prabhakaran R. , Kontopoulou M. , Zak G. , Bates P. J. , Baylis B. K.
Published: June 2006

The effect of contour laser welding parameters (laser speed, laser power, and weld pressure) on T-joint weld strength and meltdown of 30% glass reinforced nylon 6 is presented. For the range of parameters studied, meltdown was a strong function of the energy input, expressed as line energy, and pressure. Maximum weld strength, approximating that of the base material, could be obtained by optimizing the energy input. Weld strength diminished with increasing weld pressure.
Wild-type and central DNA flap defective HIV-1 lentiviral vector genomes: intracellular visualization at ultrastructural resolution levels
Authors: Arhel Nathalie J , Souquere-Besse Sylvie , Charneau Pierre
Published: June 2006

HIV-1 and other lentiviruses have the unique ability among retroviruses to efficiently replicate in non-dividing cells as a result of the active nuclear import of their DNA genome across an interphasic nuclear membrane. Previous work has shown that a three-stranded DNA structure synthesized during HIV-1 reverse transcription, called the central DNA flap, acts as a cis-determinant of HIV-1 genome nuclear import. Concordantly, DNA Flap re-insertion in lentiviral-derived gene therapy vectors stimulates gene transfer efficiencies and complements the level of nuclear import to wild-type levels quantitatively indistinguishable from wild-type virus in all cell types and tissues examined so far. In order to define the precise nature of the replicative defect of DNA flap mutant viruses, we carried out in situ DNA hybridization experiments with electron microscopy to determine the subcellular localization of DNA flap mutant and wild-type HIV-1 genomes. We found that Flap defective DNA genomes accumulate at the cytoplasmic face of the nuclear membrane with no overlap across the nuclear membrane, whereas wild-type genomes localize throughout the nuclear compartment. These data provide an unequivocal confirmation of the role of the DNA flap in HIV-1 nuclear import and further establish that the DNA flap controls a step that immediately precedes translocation through the nuclear pore. Further, the widespread distribution of wild-type genomes within the open chromatin confirms the recent genome-wide mapping of HIV-1 cDNA integration sites and points to an as-yet poorly understood step of intranuclear transport of HIV-1 pre-integration complexes.
Methionine Sulfoxide Reductases
Authors: CABREIRO FILIPE , PICOT CÉDRIC R. , FRIGUET BERTRAND , PETROPOULOS ISABELLE
Published: June 2006

Abstract:  Proteins are subject to modification by reactive oxygen species (ROS), and oxidation of specific amino acid residues can impair their biological function, leading to an alteration in cellular homeostasis. Methionine is among the amino acids the most susceptible to oxidation by almost all forms of ROS, resulting in both S and R diasteroisomeric forms of methionine sulfoxide. These modifications can be repaired specifically by the peptide methionine sulfoxide reductase A and B enzymes (MsrA and MsrB), respectively. MsrA has been detected in several organisms going from prokaryotes to eukaryotes. MsrA is tightly implicated in protection against oxidative stress and in protein maintenance, which is critical in the aging process. Several studies have shown that overexpression of MsrA led to an increased resistance against oxidative stress, while MsrA null mutants are more sensitive toward oxidative stress. Since oxidative damage is a key factor in aging, overexpression of MsrA in some organisms led to an increased life span whereas deletion of the gene led to the opposite. MsrA could also be involved, by regulating the function and/or expression of target proteins, in ROS‐mediated signal transduction. In fact, changes in gene expression, including certain oxidative stress–response genes, have been observed when MsrA is overexpressed. This review elaborates on the current knowledge in the implication of the Msr system in protection against oxidative stress and aging.
The anatomy knowledge of surgical trainees: the trainer's view
Authors: Tibrewal S
Published: June 2006

Anatomy dissection and prosection have long been at the heart of surgical practice and the majority of surgeons questioned agreed that a solid knowledge of anatomy is essential for surgical training and practice. Over recent years there has been a gradual reduction in the undergraduate anatomy curricula accompanied by closures of anatomy departments and dissecting rooms.
Origin of the specialists
Authors: Davis Ben
Published: June 2006

The surgical profession is going through a period of great change. Perhaps the area most affected by the current wave of initiatives is that of surgical training. There will inevitably be casualties as old systems are abandoned and new ones are introduced but there will also be those who flourish under the new regime. Is this a case of survival of the fittest?

In this month's Trainees' Forum, Ben Davis provides us with a fascinating examination of the principles of Darwinism and demonstrates how they can be applied to the surgical workforce of today.
STEP™ survey: what trainees want from a distance learning programme
Authors: Larvin Mike , Haine Louise , Kamal Tayyaba
Published: June 2006

The distance learning programme Surgical Training Education Programme™ (STEP™) for basic surgical trainees (BSTs) is currently being revised by a team led by the series editor, Professor Mike Larvin. The new programme for foundation trainees, STEP™ Foundation is due to be released in autumn 2006. This will be followed by STEP™ Core for surgical trainees in ST1/2 in autumn 2007. These programmes will incorporate the new curricula: Modernising Medical Careers (MMC: http://www.mmc.nhs.uk/) and the intercollegiate surgical curriculum project (ISCP: http://www.iscp.ac.uk/).
Invited Review Mechanism
Authors: Moore Anne , Poole Donna
Published: June 2006

After a detailed assessment of the College's rapid response and service review mechanism, the professional standards and regulation division has upgraded the service and renamed it the 'invited review mechanism' (IRM). Here we examine the process of the review and the new arrangements in place to support surgeons and hospitals in providing high quality surgical services.
Standards in dentistry: a new approach to address dynamic change
Authors: Eaton Kenneth
Published: June 2006

This article gives a brief overview of a new approach to publishing healthcare standards and guidelines that has been adopted by the Faculty of General Dental Practice (UK). Although the topic area is dentistry, as standards are dynamic in all areas of healthcare, the approach should be universally applicable as a mechanism to try to prevent any compendium of standards becoming rapidly out of date.
Faculty development and the Intercollegiate Surgical Curriculum Project
Authors: Thomas Bill , Alexander Francine
Published: June 2006

Faculty development is an integral part of the new surgical curriculum project (ISCP) and is fundamental to successful implementation. The faculty in this context refers to surgical trainers and all those involved in supervising and programming surgical education and training.
Consultant – not sub-consultant
Authors: Ribeiro Bernard
Published: June 2006

This College's position on the end point of training and the award of a Certificate of Completion of Training (CCT) continues to provoke comment. A report in Hospital Doctor in April 2006 quotes a trainee representative calling into question my personal position vis-à-vis the creation of a sub-consultant grade, while Hospital Doctor in its same report noted that this was not the College's position.
Targeting Foxo1 in Mice Using Antisense Oligonucleotide Improves Hepatic and Peripheral Insulin Action
Authors: Samuel Varman T. , Choi Cheol Soo , Phillips Trevor G. , Romanelli Anthony J. , Geisler John G. , Bhanot Sanjay , McKay Robert , Monia Brett , Shutter John R. , Lindberg Richard A. , Shulman Gerald I. , Veniant Murielle M.
Published: June 2006

Fasting hyperglycemia, a prominent finding in diabetes, is primarily due to increased gluconeogenesis. The transcription factor Foxo1 links insulin signaling to decreased transcription of PEPCK and glucose-6-phosphatase (G6Pase) and provides a possible therapeutic target in insulin-resistant states. Synthetic, optimized antisense oligonucleotides (ASOs) specifically inhibit Foxo1 expression. Here we show the effect of such therapy on insulin resistance in mice with diet-induced obesity (DIO). Reducing Foxo1 mRNA expression with ASO therapy in mouse hepatocytes decreased levels of Foxo1 protein and mRNA expression of PEPCK by 48 ± 4% and G6Pase by 64 ± 3%. In mice with DIO and insulin resistance, Foxo1 ASO therapy lowered plasma glucose concentration and the rate of basal endogenous glucose production. In addition, Foxo1 ASO therapy lowered both hepatic triglyceride and diacylglycerol content and improved hepatic insulin sensitivity. Foxo1 ASO also improved adipocyte insulin action. At a tissue-specific level, this manifested as improved insulin-mediated 2-deoxyglucose uptake and suppression of lipolysis. On a whole-body level, the result was improved glucose tolerance after an intraperitoneal glucose load and increased insulin-stimulated whole-body glucose disposal during a hyperinsulinemic-euglycemic clamp. In conclusion, Foxo1 ASO therapy improved both hepatic insulin and peripheral insulin action. Foxo1 is a potential therapeutic target for improving insulin resistance.
Leptin Suppresses Stearoyl-CoA Desaturase 1 by Mechanisms Independent of Insulin and Sterol Regulatory Element–Binding Protein-1c
Authors: Biddinger Sudha B. , Miyazaki Makoto , Boucher Jeremie , Ntambi James M. , Kahn C. Ronald
Published: June 2006

Stearoyl-CoA desaturase (SCD)1 catalyzes the rate-limiting reaction of monounsaturated fatty acid (MUFA) synthesis and plays an important role in the development of obesity. SCD1 is suppressed by leptin but induced by insulin. We have used animal models to dissect the effects of these hormones on SCD1. In the first model, leptin-deficient ob/ob mice were treated with either leptin alone or with both leptin and insulin to prevent the leptin-mediated fall in insulin. In the second model, mice with a liver-specific knockout of the insulin receptor (LIRKO) and their littermate controls (LOXs) were treated with leptin. As expected, leptin decreased SCD1 transcript, protein, and activity by >60% in ob/ob and LOX mice. However, the effects of leptin were not diminished by the continued presence of hyperinsulinemia in ob/ob mice treated with both leptin and insulin or the absence of insulin signaling in LIRKO mice. Furthermore, genetic knockout of sterol regulatory element–binding protein (SREBP)-1c, the lipogenic transcription factor that mediates the effects of insulin on SCD1, also had no effect on the ability of leptin to decrease either SCD1 transcript or activity. Thus, the effect of leptin on SCD1 in liver is independent of insulin and SREBP-1c, and leptin, rather than insulin, is the major regulator of hepatic MUFA synthesis in obesity-linked diabetes.
Distinct Signals Regulate AS160 Phosphorylation in Response to Insulin, AICAR, and Contraction in Mouse Skeletal Muscle
Authors: Kramer Henning F. , Witczak Carol A. , Fujii Nobuharu , Jessen Niels , Taylor Eric B. , Arnolds David E. , Sakamoto Kei , Hirshman Michael F. , Goodyear Laurie J.
Published: June 2006

Insulin and contraction increase GLUT4 translocation in skeletal muscle via distinct signaling mechanisms. Akt substrate of 160 kDa (AS160) mediates insulin-stimulated GLUT4 translocation in L6 myotubes, presumably through activation of Akt. Using in vivo, in vitro, and in situ methods, insulin, contraction, and the AMP-activated protein kinase (AMPK) activator AICAR all increased AS160 phosphorylation in mouse skeletal muscle. Insulin-stimulated AS160 phosphorylation was fully blunted by wortmannin in vitro and in Akt2 knockout (KO) mice in vivo. In contrast, contraction-stimulated AS160 phosphorylation was only partially decreased by wortmannin and unaffected in Akt2 KO mice, suggesting additional regulatory mechanisms. To determine if AMPK mediates AS160 signaling, we used AMPK α2-inactive (α2i) transgenic mice. AICAR-stimulated AS160 phosphorylation was fully inhibited, whereas contraction-stimulated AS160 phosphorylation was partially reduced in the AMPK α2i transgenic mice. Combined AMPK α2 and Akt inhibition by wortmannin treatment of AMPK α2 transgenic mice did not fully ablate contraction-stimulated AS160 phosphorylation. Maximal insulin, together with either AICAR or contraction, increased AS160 phosphorylation in an additive manner. In conclusion, AS160 may be a point of convergence linking insulin, contraction, and AICAR signaling. While Akt and AMPK α2 activities are essential for AS160 phosphorylation by insulin and AICAR, respectively, neither kinase is indispensable for the entire effects of contraction on AS160 phosphorylation.
Analysis of Mismatch Repair in Human Nuclear Extracts
Authors: Wang Huixian , Hays John B.
Published: June 2006

This unit describes an assay for completed mismatch correction along with a precise and sensitive assay for mismatch‐repair excision intermediates and a simple and efficient procedure for construction of mismatch repair substrates. These substrates are derived by ligating synthetic oligomers into a gapped plasmid generated using the sequence‐specific N.BstNBI nicking endonuclease, then the sequence‐specific nicking endonuclease N.AlwI, to introduce single nicks for initiation of excision. These methods can be easily adapted for construction and analysis of DNA‐lesion‐containing substrates to study DNA‐repair pathways other than mismatch repair.
Measurement of Protein Glutathionylation
Authors: Filipovska Aleksandra , Murphy Michael P.
Published: June 2006

Proteins contain free, exposed thiols that can be glutathionylated in the native state as a result of thiol‐disulfide exchange reactions with glutathione disulfide, catalyzed by glutaredoxin. A number of other reactions can also lead to protein glutathionylation. The modification of proteins by glutathionylation is important in oxidative damage and may be an important post‐translational modification to proteins involved in redox signaling. This unit describes methods for the identification of glutathionylated proteins and quantification of the extent of glutathionylation. The protocols described use isolated mitochondrial protein complexes, mitochondrial membranes, and intact mitochondria, but can be easily adapted to other systems.
Organelle Proteomics
Authors: Lescuyer Pierre , Chevallet Mireille , Luche Sylvie , Rabilloud Thierry
Published: June 2006

This unit describes strategies for studying the proteomes of organelles, which is one example of targeted proteomics. It relies heavily on previously published units dealing with organelle preparation, protein solubilization, and proteomics techniques. A specific commentary for organelle proteomics is provided. Specific protocols for the isolation of nuclei from various sources (cell cultures, tissues) are also provided.
Safe Use of Radioisotopes
Authors: Meisenhelder Jill , Semba Kentaro
Published: June 2006

The use of radioisotopes to label specific molecules in a defined way has greatly furthered the discovery and dissection of biochemical pathways. The development of methods to synthesize such tagged biological compounds inexpensively on an industrial scale has enabled them to be used routinely in laboratory protocols, including many detailed in this manual. Although most of these protocols involve the use of only microcurie amounts of radioactivity, some (particularly those describing the metabolic labeling of proteins or nucleic acids within cells) require amounts on the order of millicuries. In all cases where radioisotopes are used, depending on the quantity and nature of the isotope, certain precautions must be taken to ensure the safety of the scientist. It is essential to use good safety practices and proper protection to handle radioactive substances. This unit discusses handling, storage, and disposal of the isotopes most frequently used in biological research.
Basic Confocal Microscopy
Authors: Smith Carolyn L.
Published: June 2006

This unit introduces the reader to the basic principles of confocal microscopy and the design and capabilities of current confocal microscopes. The advantages and disadvantages of confocal microscopy as compared to other techniques for fluorescence imaging are described. There are also practical guidelines for sample preparation and optimizing imaging parameters and examples of some of the applications of confocal microscopy.
Tissue Culture Cell Assays Used to Analyze Listeria monocytogenes
Authors: Marquis Hélène
Published: June 2006

This unit describes tissue culture cell assays for analysis of the ability of Listeria monocytogenes to cause intracellular infection. It includes methods for evaluating the organism's ability to invade its host, to escape the primary vacuole formed upon invasion of host cells, to multiply within the cytosol of its host, and to spread from cell to cell without exiting the intracellular milieu. Each step can be evaluated quantitatively and qualitatively.
Delivery and Expression of Functional Viral RNA Genomes In Planta by Agroinfiltration
Authors: Annamalai Padmanaban , Rao A. L. N.
Published: June 2006

Agroinfiltration is a simple, efficient, and powerful approach for transient expression of viral genes as well as DNA‐based expression of full‐length RNA genomes of plant viruses for studies leading to understanding of replication, movement, and assembly. Most importantly, it results in synchronous delivery of Agrobacterium transformants to a majority of cells encompassing the infiltrated area and is therefore ideal for examining the biological activities of viruses having multipartite genomes. Because of the high transformation rate and efficient accumulation of mRNAs, the method is also ideal for analyzing biological activities of viral genomes with defective replication and cell‐to‐cell movement characteristics.
In Vitro Translation of Plant Viral RNA
Authors: Browning Karen S. , Mayberry Laura
Published: June 2006

This unit describes the preparation of a wheat germ extract that provides all the soluble components of the plant translational machinery. Many RNA plant viruses have positive‐strand genomes and the viral RNA serves as messenger RNA (mRNA). The preparation of mRNA by in vitro transcription is also described. The translation assay requires optimization of the amount of wheat germ extract, level of mRNA, and the concentration of Mg2+ and K+ for each mRNA. The translational efficiency of RNAs or mutants may be compared (e.g., capped versus uncapped RNAs to measure cap‐independent translation) or the amount/size of the protein product may be determined.
Comparing the perceived causes of the second Iraq war: a network analysis approach
Authors: Rafiq Umbereen , Jobanuptra Neera , Muncer Steven
Published: June 2006

The objective of this research was to examine the representation by British students of 11 perceived causes of the invasion of Iraq. We used network analysis to develop a network of the pattern of causes that are involved. Overall most participants identified a nexus of causes that reciprocally linked religious prejudice, racism and the history of conflict in the Middle East. They identified a reciprocal link between religious prejudice and September 11th, indicating that it was a cause and effect of religious prejudice. They also supported a link between the personalities of Bush and Saddam and economic gain, and acknowledged the effect of the first Gulf war on Saddam. We also found that Muslim participants were significantly less in favour of the invasion than Christian participants, and produced different networks of the links between causes. The study demonstrates that network analysis can be used to compare and contrast representations of a political event, and thus extends its use in the study of social representations. Aggr. Behav. 32:321–329, 2006. © 2006 Wiley‐Liss, Inc.
New Participant Role Scales: comparison between various criteria for assigning roles and indications for their validity
Authors: Goossens F.A. , Olthof T. , Dekker P.H.
Published: June 2006

The present study was set up with two aims in mind. First, to assess the psychometric characteristics of a peer‐report measure of bullying in a Dutch sample, and second, to compare relative and absolute ways of assigning roles in the bullying process. The sample consisted of 242 children (51% boys; mean age approximately 10 years) at T1. Two years later, there were 247 children (49% boys).

We made use of an adaptation of the original Participant Role Scales (PRS) Salmivalli, Lagerspetz, Björkqvist et al., 1996; Salmivalli, Lappalainen and Lagerspetz, 1998) and of the Aggression and Victimization Scale [Perry, Kusel and Perry, 1988]. This scale, called the New PRS, consisted of 32 items in total. Five highly reliable scales were distinguished with the help of CFA, one for leader‐like bullying behavior, one for follower‐like bullying behavior, and scales for outsider, defender and victim. We computed the roles according to four criteria, that is, z‐scores (a relative measure) and three different percentage scores (10%, 15% and 20%; each an absolute measure). Sociometric status was also assessed. The concordance between the various methods was moderate. Test–retest stability was also moderate. Test–retest coefficients for the scale scores were considerably higher. Links were found between the roles and sociometric status, irrespective of the method used for assigning roles. Victims were rejected, as were bullies, but defenders were popular. Gender differences indicated that boys were more often bullies or followers, and girls were more often outsiders or defenders. Absolute methods for assigning bullying roles produced fewer unclassifiable children and brought to light substantial differences between classes. Aggr. Behav. 32:343–357, 2006. © 2006 Wiley‐Liss, Inc.
Violent computer games and their effects on state hostility and Physiological arousal
Authors: Arriaga Patrícia , Esteves Francisco , Carneiro Paula , Monteiro Maria Benedicta
Published: June 2006

An experimental study was conducted to investigate the impact of violent computer games on state hostility, state anxiety and arousal. Participants were undergraduate students, aged from 18 to 25 years old. Before the experimental sessions, participants filled in self‐report measures concerning their video game habits and were also pre‐tested for aggressiveness and trait anxiety. Physiological responses (heart rate and skin conductance) were measured during the experiment. After playing, information about state hostility and state anxiety was collected. The results showed that participants who played the violent game reported significantly higher state hostility and support the assumption that an aggressive personality moderates the effect of playing a violent game on state hostility. Aggr. Behav. 32:358–371. 2006. © 2006 Wiley‐Liss, Inc.
Aggression and social status: the moderating roles of sex and peer‐valued characteristics
Authors: Vaillancourt Tracy , Hymel Shelley
Published: June 2006

Research on peer rejection has long emphasized links between aggressive behavior and peer liking, with aggressive children and adolescents being more rejected by peers. However, recent research shows that at least some aggressive students enjoy considerable power and influence and are perceived as “popular” within the peer group. To understand the processes underlying links between aggression and social status, the present research considered three distinct indices of social status (social preference, perceived popularity, and power) and investigated the degree to which the possession of peer‐valued characteristics moderated the links between status and aggression and whether these links varied by sex. A sample of 585 adolescents (grades 6–10) completed peer evaluation measures assessing social status, aggression (overt/physical, indirect/relational), and the degree to which peers possessed eight different peer‐valued characteristics (e.g., attractiveness, athleticism, etc.). Although sociometric indices of status were significantly related to perceived popularity, especially for boys, perceptions of power were more strongly linked to perceived popularity than to sociometric likeability. Moreover, the three indices of social status were differentially related to peers' assessments of aggression and to peer‐valued characteristics, with notable sex differences. As predicted, regression analyses demonstrated that the observed relationships between social status and aggression were moderated by the possession of peer‐valued characteristics; aggressive students who possessed peer‐valued characteristics enjoyed higher levels of perceived popularity and power and less disliking than those who did not. This relationship varied as a function of sex, the type of aggression considered, and the status construct predicted. Aggr. Behav. 32:396–408, 2006. © 2006 Wiley‐Liss, Inc.
Coincidental outbreak of methicillin‐resistant Staphylococcus aureus in a hematopoietic stem cell transplantation unit
Authors: Imataki Osamu , Makimoto Atsushi , Kato Shingo , Bannai Takahiro , Numa Naomi , Nukui Yoko , Morisawa Yuji , Ishida Toshihiko , Kami Masahiro , Fukuda Takahiro , Mori Shin‐ichiro , Tanosaki Ryuji , Takaue Yoichi
Published: June 2006

Background:

Methicillin‐resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens among hospital‐acquired infections, and immunocompromised patients are highly susceptive to infection. The molecular typing of isolated strains is a common method for tracing an outbreak of MRSA, but experience with this approach is still limited in the hematopoietic stem cell transplantation (HSCT) ward.

Methods:

We experienced 6 cases of MRSA infection/colonization in our 26‐bed HSCT ward during a 4‐week period. This unusual outbreak strongly suggested that the same MRSA strain was involved despite strict isolation and aseptic patient care. Clarification of the transmission pattern was critical, and we applied pulsed‐field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP) assays for evaluation.

Results and conclusion:

In four of the six cases, the pattern of bands examined by PFGE and AFLP analyses supported the idea that direct person‐to‐person transmission was very unlikely and the outbreak was coincidental. This experience highlights the clinical value of molecular typing methods for the clinical epidemiological assessment of MRSA outbreak. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
New‐onset and idiopathic thrombotic thrombocytopenic purpura: Incidence, diagnostic validity, and potential risk factors
Authors: Schech Stephanie D. , Brinker Allen , Shatin Deborah , Burgess Margaret
Published: June 2006

Objective:

The aim of this study was to determine the incidence rate for new‐onset and idiopathic thrombotic thrombocytopenic purpura (TTP) among adults 20–64 years old, the validity of diagnostic criteria, and potential risk factors for TTP.

Methods:

This retrospective observational study analyzed automated administrative data from 11 geographically dispersed U.S. health plans. Cases of TTP were identified based on the presence of an inpatient hospital claim for TTP (ICD‐9‐CM 446.6) between 1/1/97 and 12/31/01 and confirmed by medical record review. Pharmacy and medical claims were used to evaluate outpatient drug exposure and comorbidities preceding hospitalization for TTP. Cases and the base population were screened so as to result in an incidence rate for idiopathic TTP.

Results:

We confirmed new‐onset and idiopathic TTP in 9 of 15 presumptive cases for an incidence density of 1.4 per million person‐years (95% CI: 0.6–2.6). The rate increased to 1.8 per million person‐years after projection and age‐standardization. The highest incidence rate of TTP was found in patients 50–64 years old (2.8 per million person‐years; 95% CI: 0.8–7.1). These 9 patients had no apparent risk factors for TTP based on claims and medical record data.

Conclusions:

In a general U.S. population, the incidence rate of confirmed new‐onset and idiopathic TTP was lower than previously reported, but appears to be on the rise. Our findings suggest that administrative claims data are useful for identifying outpatient drug exposures and comorbidities potentially associated with TTP. Am. J. Hematol., 2006. Published 2006 Wiley‐Liss, Inc.
Use of whole blood platelet lumi‐aggregometry to optimize anti‐platelet therapy in patients with chronic myeloproliferative disorders
Authors: Manoharan A. , Gemmell R. , Hartwell T.
Published: June 2006

Twenty‐seven patients with chronic myeloproliferative disorders and in vitro evidence of platelet hyperactivity on whole blood platelet lumi‐aggregometry were commenced on anti‐platelet therapy comprising aspirin, clopidogrel, and/or odorless garlic and the studies were repeated to assess the efficacy of the therapeutic agent(s). Only 8 patients showed clear evidence of anti‐platelet effect while receiving the standard low‐dose (100 mg/day) aspirin therapy. Thirteen patients required a higher dosage of aspirin and/or an additional anti‐platelet agent to achieve therapeutic adequacy. Lumi‐aggregometry also proved useful to optimize therapy in the 6 patients who received clopidogrel or odorless garlic because of aspirin intolerance. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Functionalization of wood particles through a reactive extrusion process
Authors: Carlborn Karana , Matuana Laurent M.
Published: June 2006

Wood particles were modified in a reactive extrusion process with maleated polyethylene (MAPE) and maleated polypropylene (MAPP) compounds. Contents of MAPE were varied to study the effect of material composition on grafting efficiency during reactive extrusion, while extruder barrel temperatures and rotational screw speeds were varied to evaluate the effects of processing conditions on the modification of wood particles. Polymer molecular weight effects were followed using MAPP, with different molecular weights. Efficiency of the modification was assessed using FTIR and XPS surface analysis techniques, along with a titrimetric analysis, to verify the esterification reaction between the wood particles and maleated polyolefins. The grafting of maleated polyolefins onto the surface of the wood particles through a reaction of the hydroxyl groups on the wood surface with the maleated groups of the maleated polyolefins was confirmed, while the level of grafting of MAPE onto wood particles was determined to be a function of the MAPE concentration. However, there was no significant difference found in grafting efficiency at different extrusion processing conditions, rather all of the conditions resulted in adequate grafting. Similarly, there was no difference in grafting efficiency with the molecular weight of MAPP. Reactive extrusion was found to be a suitable technique for the modification of wood particles, with maleated polyolefins, for all of the material compositions and processing conditions studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3131–3142, 2006
Synthesis of unsaturated polyesters of increased solubility in styrene
Authors: Matynia Tadeusz , Worzakowska Marta , Tarnawski Wiesław
Published: June 2006

The present study presents the synthesis of unsaturated polyester resins using only one glycol i.e., ethylene glycol. Polyesters of inorganic solubility in styrene were prepared. Properties of the resins in the noncrosslinked state in the process of crosslinking and after curing were studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3143–3150, 2006
Synthesis, characterization, and curing of {2,6–bis‐[2‐(bis‐oxiranylmethyl‐amino)‐methylbenzyl]‐phenyl}‐bis‐oxiranylmethylamine (BPBOMA)
Authors: Maity T. , Samanta B. C. , Dalai S. , Banthia A. K.
Published: June 2006

The curing behavior of epoxy resin prepared by reacting epichlorohydrin with amine functional aniline acetaldehyde condensate (AFAAC) was investigated using AFAAC as a curing agent. The epoxy resin, {2,6‐bis‐[2‐(bis‐oxiranylmethyl‐amino)‐methylbenzyl]‐phenyl}‐bis‐oxiranylmethylamine (BPBOMA), was characterized by FTIR and 1H‐NMR spectroscopy, viscosity measurement, and determination of epoxy content. Analysis of the curing reaction was followed by differential scanning calorimetry (DSC) analysis. To investigate the curing kinetic with AFAAC, dynamic DSC scans were made at heating rates of 5, 10, 15, and 20°C/min. The activation energy and frequency factor of the AFAAC formulation were evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3168–3174, 2006
Tensile strength and its variation of PAN‐based carbon fibers. I. Statistical distribution and volume dependence
Authors: Yu Weidong , Yao Jiangwei
Published: June 2006

The effects of the diameter, gauge length, and volume of carbon fibers on the tensile properties and their variation are discussed on the basis of the weak‐link theory and Weibull distribution in a single‐filament test. As far as variation is concerned, the stress of carbon fibers should be obtained by the division of the force not by the mean cross section of all the fibers but by the cross section of individual fibers because of the diameter variation. The volume effect of carbon fibers influences not only the mean of the tensile properties but also their variation. The experimental results indicate that the volume dependence in the radial direction is much bigger than that in the axial direction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3175–3182, 2006
Polynitroalcohols obtained through nitro aldol reaction between nitro oligomers and C1‐C2‐aldehydes
Authors: Karaivanova M. S. , Nedelchev N. M.
Published: June 2006

Polynitroalcohols (PNA) were obtained by AN‐reaction of nitro oligomers from ground waste rubbers (NO‐GWR) with C1‐C2‐aldehydes in presence of organic bases triethanolamine, triethylamine and cyclopropylamine. The AN‐reaction was studied at temperatures from 30 to 50°C, time 4 h, and NO‐GWR : aldehyde = 1 : 0.5/2.0 mass ratios in the solution. PNA were characterized by elemental analyses, such as 1H NMR spectra, IR spectroscopy—baseline method with internal standard and thermal analyses. The quantitative functional composition of PNA (%NO2, %CO, and %OH groups) was proved to be similar to the composition of PNA obtained from model butadiene–styrene nitro oligomer (BSNO). It was concluded that NO‐GWR could replace NO based on elastomers in nitro aldol reaction with formaldehyde and acetaldehyde. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3241–3250, 2006
Characteristics of cellulose isolated by a totally chlorine‐free method from Caragana korshinskii
Authors: Xu F. , Sun R. C. , Lu Q.
Published: June 2006

The chemical composition and fiber morphology of Caragana korshinskii were investigated in this study. Isolation of cellulose was performed in a nonsulfur acetic acid/nitric acid system under various conditions. The influence of three factors, i.e., nitric acid concentration (0, 2, 4, 6, 8, or 10%), temperature (95, 100, 110, 115, 120, or 130°C), and reaction time (30, 40, 50, 60, or 90 min) on the cellulose properties (viscosity, yield, and molecular weight) was studied. The cellulose isolated was characterized by using Fourier transform infrared, gas chromatography, high performance liquid chromatography, solid‐state cross‐polarization magic angle spinning carbon‐13 nuclear magnetic resonance, wide‐angle X‐ray diffraction, and thermogravimetric analysis/differential scanning calorimetry techniques. The results showed that the treatment using 80% acetic acid and nitric acid as a catalyst under the given conditions resulted in slight acetylation of the cellulose and increased the degree of crystallinity of cellulose except for significant degradation of lignin and hemicellulosic polymers. The thermal stability of the cellulose declined with an increase in nitric acid concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3251–3263, 2006
Compositional differences of propylene–ethylene block copolymers manufactured by degradation and hydrogenation techniques
Authors: Zhang Chuanzhi , Yu Fusheng , Wang Li‐Qun , Tu Kehua
Published: June 2006

The purpose of the present work is to investigate the compositional difference of polypropylene–polyethylene block copolymers (PP‐b‐PE) manufactured industrially by the process of degradation and hydrogenation, respectively. Each of the PP‐b‐PE copolymers was fractionated into three fractions with heptane and chloroform. The compositions of the three fractions were characterized by 13C nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy, as well as differential scanning calorimetry (DSC) and thermal fractionation. The results showed that the Chloroform‐soluble fraction was amorphous ethylene‐propylene rubber, and the content of the rubber in PP‐b‐PE manufactured by hydrogenation was less than that by degradation. The degree of crystallinity of the chloroform‐insoluble fraction of the PP‐b‐PE manufactured by hydrogenation is higher than that of by degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3301–3306, 2006
Isothermal and nonisothermal crystallization kinetics of isotactic polypropylene nucleated with substituted aromatic heterocyclic phosphate salts
Authors: Zhang Yue‐fei , Xin Zhong
Published: June 2006

The crystallization kinetics of isotactic polypropylene (iPP) and nucleated iPP with substituted aromatic heterocyclic phosphate salts were investigated by means of a differential scanning calorimeter under isothermal and nonisothermal conditions. During isothermal crystallization, Avrami equation was used to describe the crystallization kinetics. Moreover, kinetics parameters such as the Avrami exponent n, crystallization rate constant Zt, and crystallization half‐time t1/2 were compared. The results showed that a remarkable decrease in t1/2 as well as a significant increase in overall crystallization rate was observed in the presence of monovalent salts of substituted aromatic heterocyclic phosphate, while bivalent and trivalent salts have little effect on crystallization rate of iPP. The addition of monovalent metal salts could decrease the interfacial free energy per unit area perpendicular to PP chains σe value of iPP so that the nucleation rate of iPP was increased. During nonisothermal crystallization, Caze method was used to analyze the crystallization kinetics. It also showed that monovalent metal salts had better nucleation effects than bivalent and trivalent metal salts. From the obtained Avrami exponents of iPP and nucleated iPP it could be concluded that the addition of different nucleating agents changed the crystal growth pattern of iPP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3307–3316, 2006
Ethylene polymerization by alkylidene‐bridged asymmetric dinuclear titanocene/MAO systems
Authors: Lin Feng , Sun Junquan , Liu Xijie , Lang Wuke , Xiao Xiaohui
Published: June 2006

Two asymmetric alkylidene‐bridged dinuclear titanocenium complexes (CpTiCl2)2(η5‐η5‐C9H6(CH2)nC5H4), 1 (n = 3) and 2 (n = 4) have been prepared by treating two equivalents of CpTiCl3 with the corresponding dilithium salts of the ligands C9H7(CH2)nC5H5 (n = 3, 4). Additionally, Ti(η5:η5‐n‐BuC5H4C5H5)Cl2 (3) and Ti(η5:η5‐n‐BuC9H6C5H5)Cl2 (4) were synthesized as corresponding mononuclear complexes. All complexes were characterized by 1H, 13C NMR, and IR spectroscopy. Homogenous ethylene polymerization catalyzation using those complexes has been conducted in the presence of methylaluminoxane (MAO). The influences of reaction parameters, such as [MAO]/[Cat] molar ratio, catalyst concentration, ethylene pressure, temperature, and time have been studied in detail. The results showed that the catalytic activities of both dinuclear titanocenes were higher than those of the corresponding mononuclear titanocenes. Although the two dinuclear complexes were different in only one [CH2] unit, the catalytic activity of 2 was about 50% higher than that of 1; however, the molecular weight of polyethylene (PE) obtained by 2 was lower than that obtained from 1. The molecular weight distribution of PE produced by these dinuclear complexes reached 6.9 and 7.3, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3317–3323, 2006
Sodium alginate–poly(hydroxyethylmethacrylate) interpenetrating polymeric network membranes for the pervaporation dehydration of ethanol and tetrahydrofuran
Authors: Veerapur R. S. , Gudasi K. B. , Patil M. B. , Babu V. Ramesh , Bhat S. D. , Sairam M. , Aminabhavi T. M.
Published: June 2006

Interpenetrating polymeric network (IPN) membranes of sodium alginate (NaAlg) and various amounts of poly(hydroxyethylmethacrylate) (PHEMA) have been prepared and tested for the pervaporation dehydration of ethanol and tetrahydrofuran (THF). The presence of hydrophilic PHEMA in the IPN matrix was found to be responsible for increase in membrane selectivity to water. NaAlg–PHEMA IPN membrane containing 20 wt % of PHEMA exhibited a selectivity of 571 to water for the water–ethanol mixture and 857 for water–THF mixture. These data are much better than those observed for the pristine NaAlg membrane. However, flux of the IPN membranes was smaller than that of pristine NaAlg membrane. Comparatively higher flux values were observed for water–THF mixture than for water–ethanol mixture. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3324–3329, 2006
Thermal stability of poly(ethylene‐co‐trimethylene terephthalate)s
Authors: Wei Gaofu , Hua Daoben , Gu Lixia
Published: June 2006

The thermal stability of poly(ethylene‐co‐trimethylene terephthalate) was first studied by thermogravimetry under nitrogen atmosphere at different heating rates. The results showed that the thermal behavior of the copolyester had a strong dependence on the chemical composition. The average activation energy from Ozawa technique increases with the concentration of EG units in the polyester, and a greater TG concentration in the copolyesters would decrease the onset degradation temperature. These phenomena may be attributed to the presence of one more methylene of TG unit than of EG in the copolymer. It is also noted that the yield of solid residue increases with the concentration of EG units in the polymer chain at any heating rate, which may be associated with the content of aromatic ring in the polymer chain. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3330–3335, 2006
Specially elaborated thermally induced phase separation to fabricate poly(L‐lactic acid) scaffolds with ultra large pores and good interconnectivity
Authors: Gong Yihong , Ma Zuwei , Gao Changyou , Wang Wei , Shen Jiacong
Published: June 2006

Poly(L‐lactic acid) (PLLA) scaffolds with pore diameters from several micrometers to ∼300 μm were fabricated by a specially elaborated thermally induced phase separation technique. Two different coarsening protocols, i.e., normal coarsening and multi‐step coarsening were compared in consideration of phase separation and domain growth. A normal coarsening route produced scaffolds with pore size from several micrometers to 150 μm depending on the coarsening time after phase separation, accompanying with the emergence of isolated pores at long time coarsening. Scaffolds with large pores with size up to ∼300 μm were fabricated by the two‐step coarsening technique, e.g., the PLLA‐solvent (dioxane/water) system was coarsened at a temperature after phase separation for a period, followed by coarsening at a lower temperature for another period. In parallel with formation of the large pores, the interconnectivity between pores was also improved, which was evidenced by scanning electron microscopy, gelatin solution pervasion, and collagen entrapment. The present technique provides the ability to produce scaffolds with high purity, controllable microstructures, and ease of modification, and hence can be widely used in tissue engineering field. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3336–3342, 2006
Intensification of dust removal process
Authors: Panov A. K. , Usmanova R. R. , Zaikov V. G. , Zaikov G. E.
Published: June 2006

The design of barbotage‐rotation installation with different profiles of blades of the rotator has been created on the basis of modeling method. As a result of the complexity of aerohydrodynamic research in the system “gas–liquid” carried out on the aforementioned unit, certain recommendations on the improvement of the construction and operating conditions have been developed with a view to rise the effectiveness of dust removal. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3357–3360, 2006
Property transitions in high‐density polyethylene/maleated poly(ethylene–octene)/calcium carbonate ternary composites
Authors: Xie Tingxiu , Liu Hongzhi , Ou Yuchun , Yang Guisheng
Published: June 2006

Ternary composites of high‐density polyethylene (HDPE)/maleated poly(ethylene–octene) (POE‐g)/calcium carbonate (CaCO3) were prepared by the melt extrusion process. Crystallization behavior investigation and mechanical properties study showed that there existed a transition in both crystallization temperature (Tc) and impact strength of ternary composites. These transitions were attributed to the development of morphology, with variation of concentration of POE‐g in ternary composites. The strength of interfacial adhesion also influenced the property transitions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3361–3366, 2006