bluuebunny/crossref_metadata_2025 huggingface dataset:
Monomer Reactivity and Steric Factors affecting the Synthesis of Aromatic Polyamides
Authors: Muñoz Dulce M. , Lozano Angel E. , Campa José G. De La , De Abajo Javier
Published: September 2007

A series of aromatic polyamides were synthesized by activation of aromatic diamines through a newly improved synthetic method. The polymers described herein were prepared by direct polycon-densation of isophthaloyl chloride (IPC) with silylated aromatic diamines prepared in situ by addition of chloro(trimethyl)silane (CTMS). Moreover, the same polycondensation reaction was carried out in a medium containing pyridine, to investigate the effect of the base as a promoter. The reactions were studied for diamines of different reactivity to demonstrate the feasibility of this synthetic method in polycondensation reactions. An interesting behavior was observed for sterically hindered, and therefore less reactive diamine, 4,4'-methylene-bis(2,6-dimethylaniline). The two activation methods here employed afforded readily polyamides having an inherent viscosity of 2.54 dL g-1 for the most reactive diamine (1a), when CTMS was used as the activating agent, and polyamides having an inherent viscosity of 0.65 dL g-1 for the sterically hindered diamine (1e), using the pair CTMS/Py as the activating agent. The experimental work was supported by calculations of the electronic parameters of the aromatic diamines, using quantum mechanical methods (DFT). Overall, this highly efficient one-pot method provides advantages through an easy handling and simple procedure.
Synthesis and Modifications of Polyurethanes for Biomedical Purposes
Authors: Hasirci Nesrin , Aksoy E. Ayse
Published: September 2007

Polyurethanes are known as a class of polymers with very high ‘hemocompatible‘ properties. In this study polyurethanes were prepared in various compositions and in medical purity without using any solvent, catalyst or additives. For the synthesis of polyurethanes, toluene diisocynate, diphenylmethane diisocynate or hexamethylene diisocynate were used as diisocyanate compounds and polypropylene-ethylene glycol or polypropylene glycol were used as polyol compounds. The surfaces were modified with plasma glow-discharge by using various gas atmospheres and by applying different powers. Some samples were also modified by heparin immobilization to increase the blood compatibility. Chemical structure, mechanical strength, thermal behavior, oxygen permeability, water contact angle values, as well as protein and cell attachment capabilities of the prepared and modified polyurethanes were examined as possible candidates for biomedical applications. Plasma altered the chemistry of the surface, increased hydrophilic character, and caused a decrease in protein adsorption as the applied power was increased. On the other hand, an optimum power value which caused maximum attachment for Vero cells was observed. In-vitro experiments carried out with blood cells, plasma modification caused an increase on cell adhesion while further heparin immobilization resulted with a significant decrease.
A Novel Approach to the Synthesis of High Performance and Functional Polymers
Authors: Zolotukhin1 Mikhail G. , Fomine Serguie , Lazo Luz Maria , Hernández Ma. Del Carmen G. , Guzmán-Gutiérrez M. T. , Ruiz-Trevino Alberto , Fritsch Detlev , Cuellas David Cuellas , Fernandez-G Juan M.
Published: September 2007

A novel series of linear, high molecular weight high performance and functional polymers were synthesized by a one-pot, superacid-catalyzed polyhydroxylakylation reaction of carbonyl compounds containing electron-withdrawing substituents, adjacent or relatively close to a carbocation center with non-activated aromatic hydrocarbons. The reactions were performed at room temperature in the Brønsted superacid CF3SO3H (trifluoromethanesulfonic acid, TFSA) and in a mixture of TFSA with methylene chloride, which was used as both solvent and a medium for generation of electrophilic species from the carbonyl component. Polycondensations of 1,1,1-trifluoroacetone, 2,2,2-trifluoroacetohenone, 2,7-dinitrofluorenone, acenaphthenequinone and isatin with aromatic hydrocarbons proceed readily in the presence of superacid at room temperature. The polymers obtained were found to be soluble in the common organic solvents, and flexible transparent films could be cast from the solutions. 1H and 13C NMR analyses of the polymers synthesized revealed their linear, highly regular structure. The polymers also possess high thermostability.
Branched Pentablock Poly(L-lactide-co-∊-caprolactone) Synthesis in scCO2
Authors: Saner B. , Menceloglu Y. Z. , Oncu N. Bilgin
Published: September 2007

Pentablock poly(L-lactide-co-∊-caprolactone) (PLLA/PCL), with a central fluorinated segment and four PLLA/PCL side chains was synthesized by sequential ring-opening polymerization (ROP) with stannous octoate catalyst in an environmentally benign and clean medium, scCO2. Copolymers of PLLA and PCL are extensively researched for biomedical applications. Fluorinated hydrocarbons are similarly promising for biomedicine, and especially for oxygen-carrying substitute applications. Initially, a fluorinated reactive triblock stabilizer (prepolymer, PCL-FLKT-PCL) with inner fluorinated segment and PCL side chains was synthesized in bulk from a tetraol fluorinated alcohol (FLKT) with a 99% conversion. The prepolymer was then utilized for the synthesis of copolymers in scCO2, where PLLA segments were successively incorporated to the ends of the prepolymer, forming a pentablock structure with four polyester side chains. Reactions were carried out at 75°C and 4000-4500 psi. Solubility studies of the prepolymer and the pentablock copolymer in scCO2 showed effective solubilization at the reaction temperature and pressure. The molecular weights of the products were measured with the aid of gel permeation chromatography; the prepolymer and the copolymer possessed average number molecular weights (Mn) in the range of 13 000 and 24 000 (for 96% conversion of LLA), respectively. Low poly-dispersity indexes were obtained: 1.34 for the prepolymer and 1.08-1.34 for the pentablock copolymer. Material characterization was carried out by 1H NMR, 13C NMR, 19F NMR, differential scanning calorimetry (DSC), gel permeation chromatography (GPC) and scanning electron microscopy (SEM).
Catalyst-Transfer Condensation Polymerization for the Synthesis of Well-Defined Polythiophene with Hydrophilic Side Chain and of Diblock Copolythiophene with Hydrophilic and Hydrophobic Side Chains
Authors: Yokozawa Tsutomu , Adachi Isao , Miyakoshi Ryo , Yokoyama Akihiro
Published: September 2007

Chain-growth condensation polymerization of 2-bromo-5-chloromagnesio-3-[2-(2-metho-xyethoxy)ethoxy]methylthiophene (2) with Ni catalysts was studied, and the block copolymer of poly2 and poly(3-hexylthiophene) was synthesized by this polymerization method. The polymerization of 2 depended on the ligands of the Ni catalyst, and poly2 with the lowest polydispersity was obtained when 1,2-bis(diphenylphosphino)ethane (dppe) was used as the ligand. The linear relationships between the conversion of 2 and Mn of the polymer and between the feed ratio of 2 to the Ni catalyst and Mn of the polymer indicate that this polymerization proceeds in a chain-growth polymerization manner via a catalyst-transfer condensation polymerization mechanism. The block copolymerization of 2 and 2-bromo-5-chloromagnesio-3-hexylthiophene (1) was then carried out in four ways by changing the order of polymerization of the two monomers and the catalysts. It turned out that the block copolymer was obtained without the formation of the homopolymers by the polymerization of 1 with Ni(dppe)Cl2 or Ni(dppp)Cl2 (dppp = 1,2-bis(diphenylphosphino)propane), followed by the postpolymerization of 2. Of the two catalysts, Ni(dppe)Cl2 resulted in narrower polydispersity of the block copolymer.
High Temperature Polyimide Synthesis in ‘Active’ Medium: Reactivity Leveling of the High and the Low Basic Diamines
Authors: Kuznetsov Alexander A. , Tsegelskaya Anna Yu. , Buzin Pavel V. , Yablokova Marina Yu. , Semenova Galina K.
Published: September 2007

The kinetics associated with the reaction of aromatic and aliphatic diamines with phthalic anhydride in glacial acetic acid was studied. This model system was intended to simulate the synthesis of polyimides from diamines and dianhydrides in molten benzoic acid. The reaction proceeds in two discrete steps, the first acylation occurs by the reaction of the diamine with phthalic anhydride followed by cy-clodehydration of the corresponding bis-(o-carboxyamides). The focus of the work was on the influence of chemical composition and basicity of the diamines on the kinetics. Kinetic and thermodynamic characteristics of model reactions were determined. It was established that acylation of aromatic and aliphatic diamines in acid medium proceeds as a reversible second-order reaction catalyzed by acid medium. On the basis of kinetic data obtained, an explanation is given for the observed phenomenon of reactivity leveling of diamines regardless of the basicity.
Metaphor at work in the analysis of political discourse: investigating a `preventive war' persuasion strategy
Authors: Ferrari Federica
Published: September 2007

The crucial historical moment represented by post 9/11 may undoubtedly be considered responsible for the subsequent hardening of American political rhetoric. And yet, the sudden increase of consensus catalysed by George W. Bush and the consequences of his international policy bring his modus persuadendi up for discussion. The aim of this article is to present a framework for a metaphor-based critical analysis of persuasion in political discourse. Our object of observation is George W. Bush's public speeches to the nation (2001—4). More specifically, the analysis is focused on the persuasion strategy enacted to promote the preventive war in Iraq. In our approach, conceptual metaphor as related to emotion constitutes the fundamental argumentative feature and crucial tool to address the matter of persuasion in text, contributing to identifying both the ideological root and the persuasive strategy of a given discourse in the long run. Synthesis of our results shows the potentialities of metaphor as a privileged cognitive tool for abstracting and constructing discourse strategies.
The elegance of The Elegant Universe: unity, beauty, and harmony in Brian Greene's popularization of superstring theory
Authors: Edford Rachel
Published: September 2007

The emergence of string theory into popular culture can be seen in recent episodes of Joan of Arcadia and in the NOVA series based on Brian Greene's best-selling book, The Elegant Universe. Greene's book has played a significant role in string theory's emergence into popular culture. In order to persuade the general public to accept the new and controversial theory of superstrings as a revolutionary scientific theory, Greene carefully constructs his argument in The Elegant Universe, reinforcing the elegance and beauty of string theory. The Elegant Universe itself is an elegantly constructed argument, in terms of both its overall structure and its language. The threads of Greene's argument are carefully woven to create the unified textual fabric of his argument.
Public reactions to information about genetically engineered foods: effects of information formats and male/female differences
Authors: Qin Wei , Brown J. Lynne
Published: September 2007

Developing effective communication strategies to inform the public about genetic engineering applications in food production is critical for the successful commercialization and future development of the technology. However, few existing studies in the United States have examined how communication materials affect public understanding of new technologies. Our survey study examined the effect of two information formats developed according to public issue education principles on the public understanding of, interest in and attitude towards genetically engineered salmon. In addition, we examined male/female differences in attitude. Our results indicated that participants who read the “consequence” information learned more, expressed more interest, and indicated higher level of actual confidence in judgment than those who read the “perspective” information. Women were less approving of genetically engineered salmon than men were both before and after reading the information. Reading information led to a positive change in attitude although the effect size was not different between sexes. The male/female difference was likely due to women's higher level of concern about effects on humans and greater trust of environmental groups compared to men's. Suggestions for designing an effective print communication about a specific genetic engineering application are presented.
Intensive Care Unit Nurses' Opinions About Euthanasia
Authors: Kumaş Gülşah , Öztunç Gürsel , Nazan Alparslan Z.
Published: September 2007

This study was conducted to gain opinions about euthanasia from nurses who work in intensive care units. The research was planned as a descriptive study and conducted with 186 nurses who worked in intensive care units in a university hospital, a public hospital, and a private not-for-profit hospital in Adana, Turkey, and who agreed to complete a questionnaire. Euthanasia is not legal in Turkey. One third (33.9%) of the nurses supported the legalization of euthanasia, whereas 39.8% did not. In some specific circumstances, 44.1% of the nurses thought that euthanasia was being practiced in our country. The most significant finding was that these Turkish intensive care unit nurses did not overwhelmingly support the legalization of euthanasia. Those who did support it were inclined to agree with passive rather than active euthanasia (P = 0.011).
Ethical and Methodological Issues in Interviewing Persons With Dementia
Authors: Hellström Ingrid , Nolan Mike , Nordenfelt Lennart , Lundh Ulla
Published: September 2007

People with dementia have previously not been active participants in research, with ethical difficulties often being cited as the reason for this. A wider inclusion of people with dementia in research raises several ethical and methodological challenges. This article adds to the emerging debate by reflecting on the ethical and methodological issues raised during an interview study involving people with dementia and their spouses. The study sought to explore the impact of living with dementia. We argue that there is support for the inclusion of people with dementia in research and that the benefits of participation usually far outweigh the risks, particularly when a `safe context' has been created. The role of gatekeepers as potentially responsible for excluding people with dementia needs further consideration, with particular reference to the appropriateness of viewing consent as a primarily cognitive, universalistic and exclusionary event as opposed to a more particularistic, inclusive and context relevant process.
Changes in Nursing Ethics Education in Lithuania
Authors: Toliušienė Jolanta , Peičius Eimantas
Published: September 2007

The post-Soviet scene in Lithuania is one of rapid change in medical and nursing ethics. A short introduction to the current background sets the scene for a wider discussion of ethics in health care professionals' education. Lithuania had to adapt rapidly from a politicized nursing and ethics curriculum to European regulations, and from a paternalistic style of care to one of engagement with choices and dilemmas. The relationships between professionals, and between professionals and patients, are affected by this in particular. This short article highlights these issues and how they impact on all involved.
Ethics in Nursing Education: Learning To Reflect On Care Practices
Authors: Vanlaere Linus , Gastmans Chris
Published: September 2007

Providing good care requires nurses to reflect critically on their nursing practices. Ethics education must provide nurses with tools to accomplish such critical reflection. It must also create a pedagogical context in which a caring attitude can be taught and cultivated. To achieve this twofold goal, we argue that the principles of a right-action approach, within which nurses conform to a number of minimum principles, must be integrated into a virtue ethics approach that cultivates a caring attitude. Ethics education that incorporates both the `critical companionship' method and the use of codes of ethics contributes positively to cultivating critical reflection by nurses.
Vocation in Theology-Based Nursing Theories
Authors: Lundmark Mikael
Published: September 2007

By using the concepts of intrinsicality/extrinsicality as analytic tools, the theology-based nursing theories of Ann Bradshaw and Katie Eriksson are analyzed regarding their explicit and/or implicit understanding of vocation as a motivational factor for nursing. The results show that both theories view intrinsic values as guarantees against reducing nursing practice to mechanistic applications of techniques and as being a way of reinforcing a high ethical standard. The theories explicitly (Bradshaw) or implicitly (Eriksson) advocate a vocational understanding of nursing as being essential for nursing theories. Eriksson's theory has a potential for conceptualizing an understanding of extrinsic and intrinsic motivational factors for nursing but one weakness in the theory could be the risk of slipping over to moral judgments where intrinsic factors are valued as being superior to extrinsic. Bradshaw's theory is more complex and explicit in understanding the concept of vocation and is theologically more plausible, although also more confessional.
Duty and 'Euthanasia': the Nurses of Meseritz-Obrawalde
Authors: Benedict Susan , Caplan Arthur , Lafrenz Page Traute
Published: September 2007

This article examines the actions and testimonies of 14 nurses who killed psychiatric patients at the state hospital of Meseritz-Obrawalde in the Nazi 'euthanasia' program. The nurses provided various reasons for their decisions to participate in the killings. An ethical analysis of the testimonies demonstrates that a belief in the relief of suffering, the notion that the patients would 'benefit' from death, their selection by physicians for the 'treatment' of 'euthanasia', and a perceived duty to obey unquestioningly the orders of physicians were the primary ethical reasons that were stated for their behavior. However, 20 years had elapsed between the killings and the trial, thus giving ample opportunity for the defendants to develop comfortable rationales for their actions and for their attorneys to have observed successful defenses of others accused of euthanasia.
Primary Care Nurse Practitioners' Integrity When Faced With Moral Conflict
Authors: Laabs Carolyn Ann
Published: September 2007

Primary care presents distressful moral problems for nurse practitioners (NPs) who report frustration, powerlessness, changing jobs and leaving advanced practice. The purpose of this grounded theory study was to describe the process NPs use to manage moral problems common to primary care. Twenty-three NPs were interviewed, commenting on hypothetical situations depicting ethical issues common to primary care. Coding was conducted using a constant comparative method. A theory of maintaining moral integrity emerged consisting of the phases of encountering conflict, drawing a line, finding a way without crossing the line, and evaluating actions. The NPs varied in their awareness and the discord encountered in conflict, and in clarity, flexibility and justification of the line drawn. A critical juncture occurred when NPs evaluated how well integrity had been maintained. Some experienced no distress while others experienced self-doubt, regret, outrage and frustration at external constraints, and attempted to reconcile through avoiding, convincing themselves, and compensating.
Developing Ethical Competence in Health Care Organizations
Authors: Kälvemark Sporrong Sofia , Arnetz Bengt , Hansson Mats G. , Westerholm Peter , Höglund Anna T.
Published: September 2007

Increased work complexity and financial strain in the health care sector have led to higher demands on staff to handle ethical issues. These demands can elicit stress reactions, that is, moral distress. One way to support professionals in handling ethical dilemmas is education and training in ethics. This article reports on a controlled prospective study evaluating a structured education and training program in ethics concerning its effects on moral distress. The results show that the participants were positive about the training program. Moral distress did not change significantly. This could be interpreted as competence development, with no effects on moral distress. Alternatively, the result could be attributed to shortcomings of the training program, or that it was too short, or it could be due to the evaluation instrument used. Organizational factors such as management involvement are also crucial. There is a need to design and evaluate ethics competence programs concerning their efficacy.
Using Appreciative Inquiry and Dialogical Learning To Explore Dominant Paradigms
Authors: Neville Mary Grace
Published: September 2007

Experiential learning theory, conversational learning, and seminar practices combine to shape an educational experience that is grounded in principles of appreciative inquiry. The seminar, taught to undergraduate business majors, seeks to encourage students to explore their underlying assumptions about business in society. Because postindustrial globalization renders business and society interdependent, the innovative pedagogy assumes educators hold responsibility for creating and fostering new skills in business students. Critical thinking, self-awareness, and values analysis skills support students seeking to engage with and innovate based on perspectives different from their own. A transferable methodology is proposed.
International Relations, Domestic Politics, and Asylum Admissions in the United States
Authors: Salehyan Idean , Rosenblum Marc R.
Published: September 2007

What explains variation in U.S. asylum approval rates across countries of origin? Previous research has found that humanitarian factors and diplomatic relations play an important role in shaping asylum decisions. This article examines the impact of domestic politics. The authors find that media and congressional attention play an important role in influencing how the executive branch makes enforcement decisions. Popular attention to asylum increases the importance of humanitarian concerns relative to instrumental factors. The effect of congressional attention depends on whether asylum is seen as an enforcement or humanitarian issue. The importance of these factors has also changed over time.
Functional Imaging Studies in Cannabis Users
Authors: Chang Linda , Chronicle Edward P.
Published: September 2007

Cannabis remains the most widely used illegal drug in the United States. This update examines the available literature on neuroimaging studies of the brains of cannabis users. The majority of studies examining the acute effects of delta-9-tetrahydrocannabinol (THC) administration used PET methods and concluded that administration of THC leads to increased activation in frontal and paralimbic regions and the cerebellum. These increases in activation are broadly consistent with the behavioral effects of the drug. Although there is only equivocal evidence that chronic cannabis use might result in structural brain changes, blood-oxygenation-level-dependent-fMRI studies in chronic users consistently show alterations, or neuroadaptation, in the activation of brain networks responsible for higher cognitive functions. It is not yet certain whether these changes are reversible with abstinence. Given the high prevalence of cannabis use among adolescents, studies are needed to evaluate whether cannabis use might affect the developing brain. Considerable further work, employing longitudinal designs, is also required to determine whether cannabis use causes permanent functional alterations in the brains of adults. NEUROSCIENTIST 13(5):422—432, 2007.
The Pathogenesis of Alzheimers Disease—Is It a Lifelong “Calciumopathy”?
Authors: Stutzmann Grace E.
Published: September 2007

Alzheimer's disease (AD) is a fatal neurodegenerative disorder that has no known cure, nor is there a clear mechanistic understanding of the disease process itself. Although amyloid plaques, neurofibrillary tangles, and cognitive decline are late-stage markers of the disease, it is unclear how they are initially generated, and if they represent a cause, effect, or end phase in the pathology process. Recent studies in AD models have identified marked dysregulations in calcium signaling and related downstream pathways, which occur long before the diagnostic histopathological or cognitive changes. Under normal conditions, intracellular calcium signals are coupled to effectors that maintain a healthy physiological state. Consequently, sustained up-regulation of calcium may have pathophysiological consequences. Indeed, upon reviewing the current body of literature, increased calcium levels are functionally linked to the major features and risk factors of AD: ApoE4 expression, presenilin and APP mutations, beta amyloid plaques, hyperphosphorylation of tau, apoptosis, and synaptic dysfunction. In turn, the histopathological features of AD, once formed, are capable of further increasing calcium levels, leading to a rapid feed-forward acceleration once the disease process has taken hold. The views proposed here consider that AD pathogenesis reflects long-term calcium dysregulations that ultimately serve an enabling role in the disease process. Therefore, “Calcinists” do not necessarily reject βAptist or Tauist doctrine, but rather believe that their genesis is associated with earlier calcium signaling dysregulations. NEUROSCIENTIST 13(5):546—559, 2007.
Human Facial Expressions Are Organized Functionally Across the Upper-Lower Facial Axis
Authors: Ross Elliott D. , Prodan Calin I. , Monnot Marilee
Published: September 2007

Most clinical research has focused on intensity differences of facial expressions between the right and left hemiface to explore lateralization of emotions in the brain. Observations by social psychologists, however, suggest that control of facial expression is organized predominantly across the upper-lower facial axis because of the phenomena of facial blends: simultaneous display of different emotions on the upper and lower face. Facial blends are related to social emotions and development of display rules that allow individuals to sculpt facial expressions for social and manipulative purposes. We have demonstrated that facial blends of emotion are more easily and accurately posed on the upper-lower than right-left hemiface, and that upper facial emotions are processed preferentially by the right hemisphere whereas lower facial emotions are processed preferentially by the left hemisphere. Based on these results, recent anatomical studies showing separate cortical areas for motor control of upper and lower face and the neurology of posed and spontaneous expressions of emotion, a functional-anatomic model of how the forebrain modulates facial expressions, is presented. The unique human ability to produce facial blends of emotion is, most likely, an adaptive modification linked to the evolution of speech and language. NEUROSCIENTIST 13(5):433—446, 2007.
Unfractionated Heparin but Not Enoxaparin Causes Delayed Plasma PAI-1 Depletion in Hemodialysis Patients: A Prospective Study
Authors: Naumnik Beata , Pawlak Krystyna , Mys′liwiec Michał
Published: September 2007

Background and aims. Heparin modulates function of vascular endothelial cells. We studied the effects of unfractionated heparin (UFH) versus low-molecular-weight heparin (LMWH), enoxaparin, used as anticoagulants during hemodialysis (HD) on plasma levels of circulating endothelium-derived molecules: thrombomodulin (TM), von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), cell surface adhesion molecules (E-selectin), intercellular adhesion molecule-1 (ICAM-1), and prothrombin fragment 1+2 (PF 1+2). Methods. Twenty-five patients undergoing enoxaparin-anticoagulated HD were randomly assigned either to continue enoxaparin (n = 13) or receive UFH (n = 12) during HD and followed prospectively for 12 weeks. Plasma immunoreactive TM, vWF, PAI-1, ICAM-1, E-selectin, and PF 1+2 were measured before the randomization procedure and after 12 weeks, at the start, after 10 and 180 minutes of HD. Results. The switch from LMWH to UFH resulted in decreased pre-HD levels of PAI-1 and TM and increased PF 1+2 concentrations. Predialysis PAI-1 negatively correlated with the total dose of UFH/kg/HD. No significant differences were observed in the other variables before and during HD after switching from LMWH to UFH. During enoxaparin-anticoagulated HD, only plasma PAI-1 levels decreased by 32% after 180 minutes compared with the baseline values. This percentage decrease positively correlated with predialysis PAI-1 levels and marginally with PF 1+2 concentrations after 180 minutes of enoxaparin-anticoagulated HD. Conclusion. Enoxaparin-anticoagulated HD is related to transient plasma PAI-1 decrease, whereas UFH anticoagulation may be the cause of delayed PAI-1 and TM depletion, which is an untoward consequence of enhanced coagulation activity in chronic HD patients.
The Activated Seven Lupus Anticoagulant Assay Detects Clinically Significant Antibodies
Authors: Moore Gary W. , Rangarajan Savita , Savidge Geoffrey F.
Published: September 2007

Lupus anticoagulants are a heterogeneous group of autoantibodies detected by their effects on phospholipid-dependent coagulation assays. Persistent lupus anticoagulants are associated with thrombotic disease, but not all are clinically significant. Antibody heterogeneity and reagent and test variability dictate that at least 2 tests, of different types, should be used to screen lupus anticoagulants. The objective of this study was to investigate whether the activated seven lupus anticoagulant assay detects clinically significant antibodies. Eighty-two patients with antiphospholipid syndrome (APS) and 32 with systemic lupus erythematosus + positive for activated seven lupus anticoagulant and who were without thrombosis, who were positive by activated seven lupus anticoagulant assay, were investigated for lupus anticoagulants by dilute Russell's viper venom time, dilute activated partial thromboplastin time, and Taipan snake venom time, and for anticardiolipin antibodies. Fifty-seven of the APS patients were positive for lupus anticoagulants in multiple assays, 25 in activated seven lupus anticoagulant alone. Fourteen of the latter group were previously positive in other antiphospholipid antibodies assays, and 11 had only been positive for lupus anticoagulants by activated seven lupus anticoagulant. Twenty-eight had elevated anticardiolipin antibodies, 6 of whom were from the group that was positive in activated seven lupus anticoagulant only. Eight of the systemic lupus erythematosus + lupus anticoagulants (without thrombosis) patients were positive for lupus anticoagulant by activated seven lupus anticoagulant alone and had only been positive in activated seven lupus anticoagulant previously, and none had elevated anticardiolipin antibodies. The remaining 24 patients were lupus-anticoagulant positive in multiple assays, and 9 had elevated anticardiolipin antibodies. Dilute Russell's viper venom time and Dilute activated partial thromboplastin time are widely used to detect lupus anticoagulants and are considered to detect clinically significant antibodies. Activated seven lupus anticoagulant detected antibodies in APS patients who were positive by these assays and also lupus anticoagulants undetectable by the dilute Russell's viper venom time/dilute activated partial thromboplastin time reagents used, demonstrating its utility as a first-line or second-line assay.
Hereditary Thrombophilic Risk Factors and Venous Thromboembolism in Istanbul, Turkey: The Role in Different Clinical Manifestations of Venous Thromboembolism
Authors: Okumus Gulfer , Kiyan Esen , Arseven Orhan , Tabak Levent , Diz-Kucukkaya Reyhan , Unlucerci Yesim , Abaci Neslihan , Ünaltuna Nihan Erginel , Issever Halim
Published: September 2007

The aim of this study was to investigate the hereditary thrombophilic risk factors in patients with venous thromboembolism (VTE) and whether these risk factors play a different role in patients with isolated pulmonary embolism (PE) as compared with patients with deep vein thrombosis (DVT) and patients with PE + DVT. The protein C (PC), protein S, antithrombin activities, homocysteine levels, and factor V Leiden (FVL) G1691A and prothrombin G20210A mutations were evaluated in 191 patients with VTE and 191 controls. The prevalence of FVL and PC deficiency were higher in patients ( P = .003 and P = .02, respectively). There was no significant difference for the other risk factors. The combination of thrombophilic risk factors was significantly higher in patients with DVT + PE as compared with patients with isolated PE or DVT ( P = .04). In conclusion, the most important hereditary risk factors for VTE in this study were the FVL mutation and PC deficiency.
Effect of Support Conditions on the Vibration of Laminated Composite Beams
Authors: Aşik Mehmet Zülfü , Dural Ebru
Published: September 2007

Laminated glass plate or beam used in the building industry is an architectural unit of the building formed by two or more thin glass plates or beams bonded together by an interlayer PVB (polyvinyl butyral). The behavior of laminated glass beams is complicated because the different materials have different elastic modulus. Laminated glass is very thin and can easily undergo large displacements, therefore, the equilibrium equations governing their behavior should be based on large deflection theory. In the present study, the effect of boundary conditions on the vibration of a laminated glass unit is investigated by considering the cases of simply supported and fixed supported laminated glass beams. Glass units considered in this study have two thin glass beams and an interlayer PVB. A mathematical model for the dynamic behavior of a laminated glass beam is developed using variational principles. The assumptions of the classical beam theory are valid. Three coupled partial differential equations which express the dynamic behavior are obtained for lateral and axial displacements. By solving these equations, the effect of boundary conditions on the natural frequencies is observed in figures depicting displacement versus angular frequency.
Analysis of the Van der Pol Oscillator Containing Derivatives of Fractional Order
Authors: Barbosa Ramiro S. , Machado J.A. Tenreiro , Vinagre B.M. , Calderón A.J.
Published: September 2007

In this paper a modified version of the classical Van der Pol oscillator is proposed, introducing fractional-order time derivatives into the state-space model. The resulting fractional-order Van der Pol oscillator is analyzed in the time and frequency domains, using phase portraits, spectral analysis and bifurcation diagrams. The fractional-order dynamics is illustrated through numerical simulations of the proposed schemes using approximations to fractional-order operators. Finally, the analysis is extended to the forced Van der Pol oscillator.
Fractional Euler—Lagrange Equations of Motion in Fractional Space
Authors: Muslih Sami I. , Baleanu Dumitru
Published: September 2007

Fractional variational principles have gained considerable importance during the last decade due to their various applications in several areas of science and engineering. In this study, the fractional Euler— Lagrange equations corresponding to a prescribed fractional space are obtained. These equations are obtained using the traditional method of calculus of variations adapted to the case of fractional space. The most general fractional Lagrangian is considered and the limit case when the parameters involved in fractional derivatives are equal to one, is obtained. Two examples are investigated in this study, namely the free particle on fractional space and the fractional simple pendulum, and their corresponding fractional Euler—Lagrange equations ar obtained.
Performance of Fractional PID Algorithms Controlling Nonlinear Systems with Saturation and Backlash Phenomena
Authors: Barbosa Ramiro S. , Tenreiro Machado J.A. , Galhano Alexandra M.
Published: September 2007

The development of fractional-order controllers is currently one of the most promising fields of research. However, most of the work in this area addresses the case of linear systems. This paper reports on the analysis of fractional-order control of nonlinear systems. The performance of discrete fractional-order PID controllers in the presence of several nonlinearities is discussed. Some results are provided that indicate the superior robustness of such algorithms.
Modeling and Optimal Control for Plates with Defects
Authors: Marinova Daniela , Lukarski Dimitar , Stavroulakis Georgios
Published: September 2007

This paper presents modeling and vibration control design of thin lightweight plates taking into account defects. The classical plate theory in bending is used for a finite element dynamical model. Defects are modeled in a smeared-type way by changing the physical parameters of the corresponding element. Optimal control is further studied for plates with defects supplied with sensors and actuators. LQR and H2 control schemes are considered for vibration suppression. The influence of the plate's defects on the control of the vibrations is investigated. The placement of control forces and their influence on the quality of the vibration-regulating process is considered. Numerical simulations are carried out in order to demonstrate the efficiency of the proposed control strategies.
On the Material Setting of Gradient Hyperelasticity
Authors: Kirchner Nina , Steinmann Paul
Published: September 2007

The behavior of most materials is influenced by inhomogeneously distributed microscale properties. A reliable and efficient use of microstructured materials in engineering, nanotechnology, biomedical application and earth sciences requires and justifies high efforts in their mathematical modeling and numerical treatment and has led to the development of extended continuum theories. In the field of computational mechanics, the material force method has been established to assess the configurational equilibrium of inhomogeneities, but tacitly assumes that the material behavior is described sufficiently accurately by its state variables and their first gradients. Since this restriction might be too severe, a material setting based continuum formulation for hyperelastic media involving second deformation gradients is investigated in this article. In doing so, we wish to transfer the universally accepted improvements and successes gained by considering higher gradient continua in the spatial setting to the material setting, which has been advocated as the intrinsic framework to describe material rearrangements of inhomogeneities at the microscopic level. Focusing on quasistatic conditions, the balance law of linear momentum is derived in a variational framework. The dual nature of the spatial and material setting of Boltzmann continua of grade 2 is highlighted. Based on an enhanced Eshelby stress tensor arising in the material-setting, a fracture criterion applicable to gradient continua is obtained that encompasses, in the limit of vanishing higher deformation gradients, the classical J integral of fracture mechanics.
Accelerometer cut-points and youth physical activity prevalence
Authors: Mota Jorge , Valente Mónica , Aires Luísa , Silva Pedro , Paula Santos Maria , Ribeiro José Carlos
Published: September 2007

The purpose of this study was twofold: first, to examine the effects of specific cut-off scoring points (on the estimated prevalence of meeting health-related guidelines for physical activity in youth) and, second, to document the differences in gender physical activity patterns according to two different cut-off points. The sample comprised 62 children (boys n = 23; girls n = 39) aged 8—16 years old. Children wore accelerometers for three consecutive weekdays. The daily time spent in moderate-to-vigorous physical activity (MVPA) was calculated using an equation regression developed for youth according to different cut-points. The data analysis from Freedson's cut points showed that both sexes engaged in significantly ( p ≤ .01) more MVPA when compared with Puyau's cut points. Boys engaged in significantly ( p ≤ .01) more MVPA activities than girls regardless of the cut-off point used. Our data also showed that the percentage of students that reach the physical activity/health related guidelines was significantly higher in both boys (77.3 vs 6.9 percent; p < .001) and girls (60 vs 2.3 percent; p < .001) when Freedson's cut-off point was used. Our data showed that for preventive strategies youth specific cut-off points still need to be refined and, as a result, health-related criteria for young people need to be based on further research evidence.
Perception of Air Quality and the Thermal Environment in Offices
Authors: Butala Vincenc , Muhič Simon
Published: September 2007

People's perception of the thermal environment and the quality of air in mechanically and naturally ventilated office environments is discussed. Interdisciplinary research of the indoor environment (technical and medical fields) was based on the simultaneous measurement of the thermal environment parameters, as well on as on surveying employees during their normal working activities. The survey sought to determine the health status and health problems of those surveyed in the 6 months prior to the study, as well as the current state of health and current subjective evaluation of the thermal environment and air quality. Deviations between the measured values evaluated by predicted mean vote (PMV) — predicted percent of dissatisfied (PPD) model (PMV—PDD) and the subjective evaluations of thermal environment of those surveyed were found. The subjectively stated reasons for the health problems of employees gave precedence to natural, as opposed to mechanical, ventilation, which is confirmed by the average absence from work for health reasons. An index of health was defined and analyzed for the people within a building. Significant correlations between indoor air parameters and the way people felt were found. Findings from the study indicate a significant role for the psychological factors and psychological state of the respondents when subjectively describing the indoor environment.
Perceived Importance of the Quality of the Indoor Environment in Commercial Buildings
Authors: Lai Joseph H. K. , Yik Francis W. H.
Published: September 2007

Recognition of the importance of the quality of the indoor environment (IEQ) to health, comfort and productivity of building end users has produced increasing numbers of voluntary schemes whose assessment embraces a wide spectrum of environmental attributes. Studies which aim to derive appropriate weighting factors for these attributes through soliciting the perceived importance from experts are abundant. This article reports the findings of a study which, based on face-to-face interviews with 548 end users and 66 building professionals, processed their perceived importance of IEQ using the analytical hierarchy process (AHP). Attributes included were thermal comfort, air cleanliness, odor and noise associated with the air conditioning system of typical commercial buildings. Correlation analysis of the ranking results of the AHP weights revealed the difference in perceived importance of the attributes according to gender of the respondents. Other factors also found to have influence on the perceived importance of the IEQ were whether the respondents were professionals or other end users and the reason for them working or visiting the buildings and the duration of their stay. These all varied with psychophysical factors such as personal experiences, needs and expectations. Further work is needed to study whether the weighting factors should be derived from the perceptions of experts, end users, or a balance between the two.
An Inter-comparison of VOC Types and Distribution in Different Indoor Environments in a University Campus
Authors: Chan Daniel W.T. , Tam Cinnie S.Y. , Jones A.P.
Published: September 2007

Although volatile organic compounds (VOCs) are major indoor air pollutants and ones which may affect human health it is rare to find a study about their types and distribution pattern in a university. To remedy this large-scale sampling of VOCs was conducted at different indoor environments on a university campus in Hong Kong when the HVAC system was turned on. The 54 sites selected for sampling included classrooms, offices, dining and kitchen area of canteens, workshops, laboratories and a library. All the buildings were served with mechanical ventilation and an air conditioning (MVAC) system. Samples were analysed by the USEPA's TO-14 method. VOCs discovered were divided arbitrarily into three categories: fluorinated compounds, non-aromatic chlorinated compounds and aromatic compounds. Among the VOCs detected by the TO-14 method, toluene and benzene were the most common compounds present on the campus and were present in all the samples taken. The main source for those two VOCs was ingress from outdoors.
In the middle of managers Occupational communities, global ethnography and the multinationals
Authors: Peltonen Tuomo
Published: September 2007

International management is a discipline that has yet to develop ethnographic sensitivity to the links between macro-level changes in the political economy and organizational structures and micro-level meanings and everyday life. Hassard et al. (this issue) argue that by using ethnography to study formation of middle managers' communal experiences, international management could attune to the new organizational ideology and its actualization in the everyday life of local actors in multinational corporations. In this response to Hassard et al., I note that middle managers represent a distinct occupational group that has been affected profoundly by the restructuring and delayering initiatives in corporate organizations and that their anxieties and uncertainties, shared as they may be across countries, are arguably different from the experiences of other occupational groups. Additionally, ethnographic method has traditionally studied local cultures and sites, and even the recent calls for `global ethnography' remark that ethnographic research cannot present a total vision of the world systems or transnational institutions. Instead, what ethnography can offer is description of the lives of managers and other corporate actors as they, together with the ethnographer, participate in the transnational flows, mobilities and ideologies from the viewpoint of the legacies of their local occupational and communal traditions.