bluuebunny/crossref_metadata_2025 huggingface dataset:
Parameterization approach to stability and feedback stabilization of linear time-delay systems
Authors: Mahmoud M S , Ismail A , Al-Sunni F M
Published: July 2009

This paper develops a new parameterized approach to the problems of delay-dependent analysis and feedback stabilization for a class of linear continuous-time systems with time-varying delays. An appropriate Lyapunov-Krasovskii functional is constructed to exhibit the delay-dependent dynamics. The construction guarantees avoiding bounding methods and effectively deploying injecting parametrized variables to facilitate systematic analysis. Delay-dependent stability provides a characterization of linear matrix inequalities (LMIs)-based conditions under which the linear time-delay system is asymptotically stable with a γ-level £2 gain. By delay-dependent stabilization, a state-feedback scheme is designed to guarantee that the closed-loop switched system enjoys the delay-dependent asymptotic stability with a prescribed γ-level £2 gain. It is established that the methodology provides the least conservatism in comparison with other published methods. Extension to systems with convex-bounded parameter uncertainties in all system matrices is also provided. All the developed results are tested on representative examples.
A method to monitor non-ferrous debris in ferrographic analysis
Authors: Liu T-G , Liu S-J , Yang Z-Y
Published: July 2009

Non-ferrous debris in oil sample provide important information about the wear condition of a wear couple containing non-ferrous metal components. In order to collect wear debris of non-ferrous metal material more effectively and deposit them on a ferrogram in a stable depositing ratio, the method of employing magnetic fluid as a magnetization agent to collect non-ferrous wear debris in ferrography was attempted. Magnetic fluid constituting Fe3O4 magnetic particles was prepared using a precipitation reaction. Tetrachloroethylene was used as a carrier liquid to ensure that magnetic fluid can be easily mixed with lubricant oil sample. Oleic acid was used as a surfactant, which enables magnetic particles to adhere to the surface of non-ferrous wear debris. Then the non-ferrous wear debris was magnetized and deposited on a ferrogram in a stable depositing ratio. Copper debris was chosen as an example of non-ferrous debris to illustrate the magnetization effect of the magnetic fluid. With the help of magnetic fluid, the ferrographic analyst will achieve the operating condition of the machine more accurately.
On the squeeze flow between two rigid spheres with partially wetted surfaces
Authors: Li W-L
Published: July 2009

The effects of flow rheology and wall slip on the isothermal squeeze film flow between two spherical hydrophobic surfaces are derived analytically. The non-Newtonian power-law model as well as the Navier-slip boundary conditions is considered in the partially wetted bearings. The squeeze flow and the viscous forces between two rigid spheres are discussed for various combinations of flow index, squeeze velocity, minimum film thickness, and slip lengths.
Mechanical properties and wear behaviours of CrN/TaN nanoscale multilayered thin films
Authors: Kim Y J , Byun T J , Han J G
Published: July 2009

CrN/TaN nanoscale multilayered thin films with a lamination of hard transition metal nitrides were deposited by closed field unbalanced magnetron sputtering (CFUBMS). The bilayer period (λ) of all of the laminated layers was controlled within the range from 4.3 to 43 nm. The CrN/TaN nanoscale multilayered thin films exhibited a (200) preferred orientation. The mechanical properties of the thin films, as determined by nano-indentation testing, showed a dependence on various bilayer periods (λ). The multilayer with a bilayer period of 5.4 nm exhibited high hardness, high resistance to plastic deformation, and high wear resistance.
Airborne wear particles from passenger car disc brakes: A comparison of measurements from field tests, a disc brake assembly test stand, and a pin-on-disc machine
Authors: Wahlström J , Söderberg A , Olander L , Olofsson U , Jansson A
Published: July 2009

Most modern passenger cars have disc brakes on the front wheels. Unlike drum brakes, disc brakes are not sealed off from the ambient air. During braking, both the rotor and the pads wear, and this wear process generates particles that may become airborne. In field tests it is difficult to distinguish these particles from others in the environment. It is thus preferable to conduct tests using laboratory test stands where the cleanness of the surrounding air can be controlled. However, the validity of results from these test stands should be verified by comparison with field tests. This article presents a comparison of the number and volume distributions of airborne wear particles as measured online in field tests, in a disc brake assembly test stand, and in a pin-on-disc machine. In all cases, grey cast iron rotors and low metallic pads were tested. A promising correlation between the three different test methods is shown. The number- and volume-weighted mean particle diameter for all test methods is about 0.4 and 2-3 μm, respectively.
On the utilization of pin-on-disc simulative tests for the calibration of friction in metal cutting
Authors: Cristino V A M , Rosa P A R , Martins P A F
Published: July 2009

This article proposes a new design for pin-on-disc machines and introduces a research methodology that aims at providing a new level of understanding for the influence of surface texture and roughness on the average value of the friction coefficient.

The new design for pin-on-disc machines increases the overall stiffness, eliminates the need for counter weights, and allows tests to be carried out under variable loading conditions and includes a unit for producing and regenerating the desired texture and roughness in the surface of the discs after completion of each test.

The comparison between the friction coefficient obtained with pin-on-disc tests and that acquired in metal cutting laboratory conditions allows concluding that pin-on-disc tests, when performed with an adequate control of texture and surface roughness, are capable of providing a good estimate of the average value of the friction coefficient in metal cutting applications.
Modelling and analysis of erosion wear behaviour of hybrid composites using Taguchi experimental design
Authors: Mahapatra S S
Published: July 2009

This article describes the development of multi-phase hybrid composites consisting of polyester reinforced with E-glass fibre and ceramic particulates. It further investigates the erosion wear response of these composites and presents a comparison on the influence of two different particulate fillers cement by-pass dust (CBPD) and alumina (Al2O3) on the wear characteristics of glass-polyester composites. For this purpose, the erosion test schedule in an air jet-type test rig is made following design of experiment approach using Taguchi's orthogonal arrays. Taguchi approach enables one to determine optimal parameter settings that lead to minimization of erosion rate. The results indicate that erodent size, filler content, impingement angle, and impact velocity influence the wear rate significantly. This study reveals that addition of hard particulate fillers like CBPD and Al2O3 improves the erosion resistance of glass-polyester composites significantly. An industrial waste like CBPD exhibits reasonably good filler characteristics. Finally, a popular evolutionary approach known as genetic algorithm is used to generalize the method of finding out optimal factor settings for minimum wear rate.
Non-invasive detection of the anaerobic threshold by a neural network model of the heart rate—work rate relationship
Authors: Erdogan A , Cetin C , Goksu H , Guner R , Baydar M L
Published: July 2009

The heart rates (HRs) indicating the anaerobic threshold, which corresponds to a fixed blood lactate concentration of 4mmol/l (heart rate at the onset of blood lactate accumulation (HR-OBLA)); are predicted on the basis of the heart rate—work rate relationship during exercise performance. The predictor is a multi-layer perceptron (MLP). For training and testing, 225 male soccer players (mean age, 21.6±4.5 years) performed an incremental running test on a treadmill with 3-min runs and 30-s blood sampling sessions for lactate assessment. In addition to the treadmill test data, the ages, masses, heights, body mass indices, and playing positions of half of the subjects ( n=113) were used to train the MLP and the remaining 112 were used for external validation. The results showed that the HR values recorded in the last stages before exhaustion were strong predictors of HR-OBLA ( r=0.875; standard error of estimates, 4.17). Inclusion of other parameters did not improve the prediction rate. Although additional work is needed to generalize the method to training prescription, results suggest that a neural network is a promising non-invasive tool for accurately estimating the HR-OBLA from exercise test data.
Synthesis and Properties of Stable 1,2-Bis(metallocenyl)disilenes: Novel d–π Conjugated Systems with a Si=Si Double Bond
Authors: Yuasa Akihiro , Sasamori Takahiro , Hosoi Yoshinobu , Furukawa Yukio , Tokitoh Norihiro
Published: July 2009

Stable 1,2-bis(metallocenyl)disilenes were synthesized for the first time and were characterized by spectroscopic and X-ray crystallographic analyses. On the basis of cyclic voltammograms, (E)-1,2-bis(ferrocenyl)-1,2-bis(2,4,6-triisopropylphenyl)disilene (1a) was found to be a stable five-electron redox system with four steps, while (E)-1,2-bis(ruthenocenyl)-1,2-bis(2,4,6-triisopropylphenyl)disilene (1b) showed four-step redox couples with four electrons. The UV–vis spectra and theoretical calculations for these disilenes suggested that they should be novel d–π conjugated systems containing a disilene unit. In addition, chalcogenation reactions of 1a resulted in the formation of new heterocyclic compounds bearing ferrocenyl units. For example, the first stable 1,2,3,4-dithiadisiletane derivative was obtained by the sulfurization reaction of 1a.
Baeyer–Villiger Oxidation of Cycloalkanones with In Situ Generated Hydrogen Peroxide from Alcohols and Molecular Oxygen Using NHPI as a Key Catalyst
Authors: Kamae Kenichiro , Obora Yasushi , Ishii Yasutaka
Published: July 2009

One-pot Baeyer–Villiger oxidation of cycloalkanones was successfully achieved by allowing them to react with hydrogen peroxide generated in situ from benzhydrol and molecular oxygen assisted by N-hydroxyphthalimide (NHPI) and 2,2′-azobisisobutyronitrile (AIBN). This method provides an alternative synthetic route to lactones from cycloalkanones using sec-alcohols and molecular oxygen assisted by NHPI.
Accelerated Examination & Grant of Japanese Biotechnology Patents
Authors: Tessensohn John A. , Yamamoto Shusaku
Published: July 2009

The healthcare transformational capacity of biotechnology intellectual property makes it fundamental that such biotech patents are issued promptly in order to have clarity and certainty in the research community and the marketplace. In these economically challenging times, accelerated patent grants will make biotech patent owners more attractive to investors and licensors ensuring their survival. Japanese universities have aggressively patented and licensed their biotech research and utilized the accelerated patent system to procure the world's first ever induced pluripotent stem cells (iPS) patent. This article examines the various accelerated examination procedures available at the Japan Patent Office and how biotechnology patent applicants can secure early patent protection in Japan, the world's second largest biopharmaceutical market.
Efforts to Overcome Sex Selection in Reproduction in Asia
Authors: Macer Darryl
Published: July 2009

There is significant abuse of medical diagnostic technology in some Asian countries to select male fetuses and embryos over female fetuses, which leads to an imbalanced sex ration at birth. The paper discusses the ethics of sex selection, and reviews policies that have been used. Legal measures to prevent this in China and India are described, as well as the reasons that those efforts have not solved the problem. There are also growing uses of technology for sex selection in Nepal and Vietnam. The Republic of Korea has used policies and education to reverse preference for boys, and there is discussion of the reasons behind this. New partners and policies are required to overcome this serious abuse of biotechnology that is responsible for close to one hundred million missing girls in the world population.
Penrose’s law: reality or fiction? Mental health system and the size of prison population – international overview
Authors: Kalapos Miklós Péter
Published: July 2009

A múlt század harmincas éveiben az európai összehasonlító statisztikai adatok alapján kidolgozott Penrose-törvény szerint inverz összefüggés van a pszichiátriai ágyak száma és a börtönben lévő populáció létszáma között. A dolgozat nemzetközi adatok alapján vizsgálja a börtön, az elmekórház, az elmebetegség és a bűnelkövetés összefüggéseit, különös figyelmet szentelve a deinstitucionalizáció jelenségének, illetve epidemiológiai adatok segítségével bemutatja az elme- és addikciós betegségek, valamint a mentális zavarok börtönön belüli gyakoriságát. A pszichiátriai ágyak száma és a börtönpopuláció létszáma között Magyarország esetében is megfigyelhető a Penrose által leírt inverz összefüggés. A jelenség mélyebb összefüggéseinek elemzése során a deinstitucionalizációt elindító jelenségeket górcső alá véve gazdasági, társadalmi, filozófiai és terápiás összefüggések kerülnek a vizsgálat homlokterébe. Az adatok alapján feltételezhető, hogy a két rendszerbe bekerülők között nagy az átfedés, nagyrészt ugyanazon populáció tagjaival találkozhatunk mind a börtönökben, mind az elmeosztályokon. A dolgozat szerzője arra a következtetésre jut, hogy a deinstitucionalizáció valójában transzinstitucionalizációhoz vezet, aminek oka egyrészt az, hogy korlátozott a rendelkezésre álló közösségi ellátókapacitás, illetve másrészt, hogy a közösségi ellátás maga nem tud mit kezdeni a súlyos, krónikus elmebetegségekben, illetve a komorbid állapotokban is szenvedőkkel. Továbbá a jelen finanszírozás mértéke, valamint a prevenciós és terápiás módszerek nem alkalmasak arra, hogy a pácienseket megóvják a forgóajtó hatásaitól.
Manifestations of systemic mycoses and related infections in the central nervous system
Authors: Tahin Balázs , Cooke Justin , Grasselly Magdolna , Iványi János László , Szima Barna , Bobest Mátyás , Ligeti Erika , Brittig Ferenc , Garzuly Ferenc , Tóth Csaba
Published: July 2009

A hétköznapi klinikai gyakorlatban a központi idegrendszer gombás fertőzései gyakoribbá váltak. Ennek leginkább ismert okai a kortikoszteroidok, immunszuppresszív gyógyszerek, citosztatikumok, antibiotikumok egyre szélesebb körű alkalmazása, az AIDS elterjedése, az életben tartható koraszülöttek mind nagyobb száma. A szerzők a diagnosztikus problémák illusztrálására eseteket mutatnak be.Esetismertetés:1. Multifokális haemorrhagiás agyi infarktus generalizált aspergillosis következtében, köpenysejtes malignus lymphomában. 2. Éretlen koraszülöttben kialakult cerebralis microabscessusok szisztémás candidiasis talaján. 3. A comb térfoglaló daganatát utánzó, az agyban radiológiailag metasztázisnak tűnő tályogot, a tüdőben gyulladást okozó lethalis actinomycosis. 4. Idegsebészeti szövetmintából diagnosztizált nocardiosis. A visszatérő, migráló pneumonia, majd agyi tályogok miatt hosszasan kezelt beteg a megfelelő terápiára gyógyult.Megbeszélés:Fel kell készülnünk a veszélyeztetett betegek gombás infekciójának kialakulására – elsősorban aspergillosisra és candidiasisra –, ezek jelentős része a központi idegrendszerre is ráterjed. Az actinomycosis és a nocardiosis kezelésre jobban reagál, felismerésük, kezelésük életmentő.Következtetések:Terápiás kilátásaink javulnak, ha a nagy rizikójú betegek jelentős mortalitást okozó mycosisainak lehetőségével számolva, azokat időben – még az idegrendszeri részvétel előtt – kórismézzük és kezeljük.
Effects of Hydrogen Plasma Treatment on Hysteresis Phenomenon and Electrical Properties for Solid Phase Crystallized Silicon Thin Film Transistors
Authors: Choi Sung-Hwan , Park Sang-Geun , Kim Chang-Yeon , Han Min-Koo
Published: July 2009

We have investigated the effects of hydrogen plasma treatment on the hysteresis phenomenon and electrical properties of solid phase crystallized silicon thin film transistors (SPC-Si TFTs) employing alternating magnetic field crystallization (AMFC). We employed H2 plasma treatment on the SPC-Si active layer before SiO2 gate insulator deposition. By increasng the power and time duration of H2 plasma treatment, it was observed that hysteresis phenomenon of SPC-Si TFT was suppressed and electrical properties such as threshold voltage, field effect mobility was improved considerably. This is due to role of hydrogen atom by passivating the defects and grain boundary trap states in SPC-Si film. However, relatively high power and long hydrogen plasma treatment (100W, 5 minutes) could degrade the electrical characteristics of the device. SPC-Si TFT for 100W power of PECVD and 3 minutes with the H2 plasma treatment exhibit the significant improvement of electrical characterics (VTH = - 3.85V, μFE = 21.16cm2/Vs), and a smaller hysteresis phenomenon (∆VTH = -0.30V) which is suitable for high quality AMOLED Display.
Gas Phase Conditions for Obtaining Device Quality Amorphous Silicon at Low Temperature and High Deposition Rate
Authors: Rath Jatindra Kumar , de Jong Minne , Verkerk Arjan , Brinza Monica , Schropp Ruud E.I.
Published: July 2009

The aim of this paper is to find a parameter space for deposition of amorphous silicon films at low substrate temperature by VHF PECVD process for application in solar cell fabrication on cheap plastics. Our studies show that at lower substrate temperature, keeping the pressure constant, the ion energy flux reaching the growth surface decreases, which we partly attribute to increasing gas phase collisions arising from an increase in gas density. The role of hydrogen is two fold: (1) higher hydrogen dilution increases the ion energy and restores it to its required value at low temperatures; (2) a normal to dusty plasma transition occurs at lower hydrogen to silane flow ratio and this transition regime shifts to higher dilution ratios for lower substrate temperatures. Thus the role of high hydrogen dilution at low temperature is to avoid the dusty regime. Thus the role of high hydrogen dilution at low temperature is to avoid the dusty regime. The ion energy flux at low substrate temperature can also be restored to the value obtained at high substrate temperature, without increasing hydrogen dilution, by simply lowering the chamber pressure or increasing the delivered plasma power, though the IEDFs in these cases differ substantially from the IEDF at high temperature conditions. We propose that a low pressure or high power in combination with a modest hydrogen dilution (high enough to avoid dusty regime) will deliver silicon films at low temperature without sacrificing deposition rate.
Work Function Effects of Nano Structured ZnO Thin Film on the Acetone Gas Sensitivity
Authors: Jee Seung Hyun , Kakati Nitul , Kim Soo Ho , Kim Dong-Joo , Yoon Young Soo
Published: July 2009

We deposited various nano structured ZnO thin films with plasma treatment on an alumina substrate and fabricate ZnO sensors for acetone detection. The ZnO sensors with various nano structures and the plasma treatment were deposited by radio frequency (RF) magnetron sputtering method with RuO2 micro heater and Ru electrode. In order to control a work function intentionally, the various deposition conditions and the plasma treatment were used. Sensitivities of the ZnO sensor were measured in acetone vapor and air at 250 degree C. In conclusion, we suggested that the sensitivity of ZnO sensors for acetone strongly depends on the work function of the as-deposited or plasma treated nano structured ZnO thin films.
Formation of Cr-rich Nano-clusters and Columns in (Zn,Cr)Te Grown by MBE
Authors: Nishio Yôtarõ , Ishikawa Kôichirô , Kuroda Shinji , Mitome Masanori , Bando Yoshio
Published: July 2009

The correlation between the Cr aggregation and magnetic properties are investigated for the series of Zn1-xCrxTe films grown by MBE with a systematic variation of growth conditions. Structural and chemical analyses using TEM and energy-dispersive X-ray spectroscopy (EDS) reveal that the crystallinity and the Cr distribution change significantly with the substrate temperature during the MBE growth. For a relatively low average Cr content x ≅ 0.05, it is found that the crystal quality is improved with the increase of the substrate temperature. For a higher average Cr content x ≅ 0.2, the shape of Cr-rich regions is transformed from isolated clusters into one-dimensional nanocolumns with the increase of the substrate temperature. The direction of the nanocolumn formation changes depending on the crystallographic orientation of the grown films. In the magnetization measurements, anisotropic magnetic properties are observed in the films in which Cr-rich nanocolumns are formed in the vertical direction, depending on the relation between the direction of the nanocolumns and the applied magnetic fields.
Influence of Scaffold Composition on Gene Expression and Cellular Organization in Tissue-engineered Middle Phalanx Models of Human Digits
Authors: Landis William , Wada Yoshitaka , Enjo Mitsuhiro , Jacquet Robin , Lowder Elizabeth M. , Isogai Noritaka
Published: July 2009

To augment or replace defective, diseased, or impaired human digits, the design and development of tissue-engineered phalanges are important and include a middle phalanx model. This construct consists in part of two square-shaped biodegradable polyglycolic acid (PGA) scaffolds (1 x 1 x 0.2 cm in length, width and thickness, respectively) seeded with cartilage cells (chondrocytes) obtained from young calves. One such seeded scaffold is sutured to each end of a rectangular-shaped scaffold (˜2 x 0.7 x 0.5 cm in length, width and thickness) serving as the midshaft of the model. To examine the biological regenerative capacity of these biomimetic composites, midshafts were left uncovered or wrapped with periosteum, a tissue from calves giving rise to cartilage and bone. Midshafts were composed of poly(L-lactide-ε-caprolactone) [P(LA-CL)] or one of two ceramics, hydroxyapatite (HA) or β-tricalcium phosphate (β-TCP), admixed with P(LA-CL). When engineered middle phalanx models were implanted and grown for up to 20 weeks under dorsal skin flaps of athymic (nude) mice, resulting constructs varied in their midshaft bone and end plate cartilage composition and structure. Harvested from mice at 20 weeks, all constructs (n = 3 for each type) without periosteum developed viable end plate cartilage as determined by Safranin-O staining for chondrocyte-secreted proteoglycans but cells were not organized as in normal growth plate cartilage of human digits. Midshafts remained devoid of cells and mineral. Implanted for the same time 20 week period, constructs of P(LA-CL) (n = 3), HA-P(LA-CL) (n = 3), or β-TCP-P(LA-CL) (n = 3) and enclosed by periosteum each developed viable end plate cartilage whose chondrocytes were organized into columns resembling normal growth plate cartilage of digits. Midshafts mineralized through the normal process of endochondral ossification. While these features were common to all periosteum-wrapped composites, specific differences occurred between them, apparently depending on midshaft copolymer composition. In particular after 10 or 20 weeks of implantation, gene expression of end plate chondrocytes varied in their levels of type II collagen, aggrecan (proteoglycan), or bone sialoprotein, all markers for development of normal cartilage extracellular matrix and mineralization. These results indicate that the composition of midshaft scaffolds comprising middle phalanx models of human digits affects the composition and structure of both midshaft bone and end plate cartilage of constructs. Continuing studies are defining more completely the relationships between structure and composition of bone and cartilage tissues developed and properties of their underlying copolymer scaffolds in these biomineralized models.
Hybrid Polymer/Ultrathin Porous Nanocrystalline Silicon Membranes System for Flow-through Chemical Vapor and Gas Detection
Authors: Kavalenka Maryna , Fang David , Striemer Christopher C , McGrath James L , Fauchet Philippe M
Published: July 2009

Here we discuss a novel capacitive-type chemical sensor structure that uses recently discovered porous nanocrystalline silicon (pnc-Si) membranes [1] covered with metal as the capacitor plates while a polymer layer sandwiched between them serves as the sensing layer for solvent vapor detection. Pnc-Si is new ultrathin (15 nm) membrane material with pore sizes ranging from 5 to 50 nm and porosities from < 0.1 to 15 % that is fabricated using standard silicon semiconductor processing techniques. We present a study of pnc-Si membranes as a platform for such a sensor. The degree of swelling and the reversibility of the polymer/pnc-Si membrane system immersed in analyte-containing vapors are observed using optical and electrical techniques.
Can Apparent Electrical Conductivity Improve the Spatial Characterization of Soil Organic Carbon?
Authors: Martinez Gonzalo , Vanderlinden Karl , Ordóñez Rafaela , Muriel José L.
Published: July 2009

Ancillary information, such as apparent electrical conductivity (ECa), can improve the spatial and temporal estimation of soil properties. The purpose of this study was to determine if ECacould be used for the spatial characterization of soil organic C (SOC) within a long‐term tillage experiment. Apparent electrical conductivity was measured using an electromagnetic induction sensor, the EM38DD, and its predictive potential for mapping SOC was evaluated. The ECamaps showed clear differences between the conventional tillage and direct drilling plots, with higher ECaand SOC in the direct drilling plots. A normalized ECadifference (ΔECa), calculated as the difference between the normalized vertical and horizontal dipole ECavalues (ECaVand ECaH, respectively) successfully classified the SOC observations according to their corresponding management systems. Maps of ΔECa(FKM1) and ECaVand ECaH(FKM2) classified by fuzzyk‐means accounted for 30% of the total SOC variability, whereas the individual plots and management strategy explained 44 and 41%, respectively. Simple kriging with local varying means using either FKM2 or plot‐average SOC as secondary information reduced the RMSE by 8% and increased the efficiency index by about 70% compared with ordinary kriging. Despite the low point‐to‐point correlation between ECaand SOC, ECawas shown to be useful for the spatial estimation of SOC.
Comparing probabilistic microbial risk assessments for drinking water against daily rather than annualised infection probability targets
Authors: Signor R. S. , Ashbolt N. J.
Published: July 2009

Some national drinking water guidelines provide guidance on how to define ‘safe’ drinking water. Regarding microbial water quality, a common position is that the chance of an individual becoming infected by some reference waterborne pathogen (e.g. Cryptsporidium) present in the drinking water should <10−4 in any year. However the instantaneous levels of risk to a water consumer vary over the course of a year, and waterborne disease outbreaks have been associated with shorter-duration periods of heightened risk. Performing probabilistic microbial risk assessments is becoming commonplace to capture the impacts of temporal variability on overall infection risk levels. A case is presented here for adoption of a shorter-duration reference period (i.e. daily) infection probability target over which to assess, report and benchmark such risks. A daily infection probability benchmark may provide added incentive and guidance for exercising control over short-term adverse risk fluctuation events and their causes. Management planning could involve outlining measures so that the daily target is met under a variety of pre-identified event scenarios. Other benefits of a daily target could include providing a platform for managers to design and assess management initiatives, as well as simplifying the technical components of the risk assessment process.
What We Mean by Social Determinants of Health
Authors: Navarro Vicente
Published: July 2009

This article analyzes the changes in health conditions and quality of life in the populations of developed and developing countries over the past 30 years, resulting from neoliberal policies developed by many governments and promoted by the World Bank, International Monetary Fund, World Health Organization, and other international agencies. It challenges interpretations by the analysts of “globalization,” including the common assumption that states are disappearing. The author shows that what has been happening is not a reduction of state interventions but a change in the nature and character of those interventions, resulting from major changes in class (and race and gender) power relations in each country, with establishment of an alliance between the dominant classes of developed and developing countries—a class alliance responsible for the promotion of its ideology, neoliberalism. This is the cause of the enormous health inequalities in the world today. The article concludes with a critical analysis of the WHO report on social determinants of health, applauding its analysis and many of its recommendations, but faulting it for ignoring the power relations that shape these social determinants. It is not inequalities that kill people, as the report states; it is those who are responsible for these inequalities that kill people.
Policies to Tackle Health Inequalities in Norway: From Laggard to Pioneer?
Authors: Dahl Espen , Lie Marit
Published: July 2009

This study addresses recent public health policies in Norway, asking how policies on health inequalities have developed over the past 20 years. The authors focus on how the problem has been defined, what goals have been set, and what means have been put forward to achieve them. The data consist of official documents and interviews of key actors in research and the health bureaucracy. The results indicate that the theme of health inequalities has developed from a non-topic to a high-priority topic in Norway's public health policy. This change has been accompanied by formulation of clear goals and an overarching and long-term strategy, including concrete means to reduce health inequalities. Over the past five years, the problem definition has changed from one of individualization with a focus on health behaviors to a structural understanding that emphasizes the problem of the gradient and social determinants of health. Norway is on the move from a state of political indifference toward action in developing comprehensive, coordinating policy.
Post-transcriptional Regulation of Gene Expression in Plants during Abiotic Stress
Authors: Floris Maïna , Mahgoub Hany , Lanet Elodie , Robaglia Christophe , Menand Benoît
Published: July 2009

Land plants are anchored in one place for most of their life cycle and therefore must constantly adapt their growth and metabolism to abiotic stresses such as light intensity, temperature and the availability of water and essential minerals. Thus, plants’ subsistence depends on their ability to regulate rapidly gene expression in order to adapt their physiology to their environment. Recent studies indicate that post-transcriptional regulations of gene expression play an important role in how plants respond to abiotic stresses. We will review the different mechanisms of post-transcriptional regulation of nuclear genes expression including messenger RNA (mRNA) processing, stability, localization and protein translation, and discuss their relative importance for plant adaptation to abiotic stress.
Leishmanicidal Activity of Aliphatic and Aromatic Lactones: Correlation Structure-Activity
Authors: Castaño Marcela , Cardona Wilson , Quiñones Winston , Robledo Sara , Echeverri Fernando
Published: July 2009

Several aliphatic and aromatic lactones and two dimers were synthesized using the sequence: allylation - esterification - metathesis. These compounds were active in vitro against intracellular amastigotes of Leishmania panamensis. The structure-activity relationship showed the importance of the aliphatic side chain to enhance the biological activity and to obtain lower cytotoxicity. It was also observed that a decrease in the size of the lactone ring increases the selectivity index.
Design and Synthesis of Some Thiazolidin-4-ones Based on (7-Hydroxy-2-oxo-2H-chromen-4-yl) Acetic Acid
Authors: Cacic Milan , Molnar Maja , Balic Tomislav , Draca Nela , Rajkovic Valentina
Published: July 2009

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid methyl ester(1) upon reaction with ethyl bromoacetate furnishes (7-ethoxycarbonylmethoxy-2-oxo-2H-chromen-4-yl)-acetic acid methylester (2), which on treatment with 100% hydrazine hydrate yields (7-hydrazinocarbonylmethoxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (3). The condensation of compound 3 with different aromatic aldehydes afforded a series of [7-(arylidenehydrazinocarbonylmethoxy)-2-oxo-2H-chromen-4-yl]-acetic acid arylidene-hydrazide Schiff’s bases 4a-k. Cyclo-condensation of compounds 4a-k with 2-mercapto-acetic acid in N,N-dimethylformamide in the presence of anhydrous ZnCl2 affordsN-(2-aryl-4-oxothiazolidin-3-yl)-2-(4-(2-aryl-4-oxothiazolidin-3-ylcarbamoyl)-methyl)-2-oxo-2H-chromen-7-yloxy)-acetamides 5a-k. Structure elucidation of the products has been accomplished on the basis of elemental analysis, IR, 1H-NMR and 13C-NMR data. Compounds 4a-k and 5a-k will be screened for their antibacterial activity against both Gram-positive and Gram-negative bacteria and the results reported elsewhere in due course.
Hydrogenation of Phenol in Supercritical Carbon Dioxide Catalyzed by Palladium Supported on Al‐MCM‐41: A Facile Route for One‐Pot Cyclohexanone Formation
Authors: Chatterjee M. , Kawanami H. , Sato M. , Chatterjee A. , Yokoyama T. , Suzuki T.
Published: July 2009

The hydrogenation of phenol has been carried out in supercritical carbon dioxide (scCO2) under very mild reaction conditions at the temperature of 50 °C over palladium supported Al‐MCM‐41 (metal loading ∼1%). This palladium catalyst is shown to be highly active and promotes the selective formation of cyclohexanone (∼98%), an industrially important compound, in a “one‐pot” way. The effects of different variables like carbon dioxide and hydrogen pressure, reaction time and also silica/alumina ratio of the MCM‐41 support along with palladium dispersion are presented and discussed. The pressure effect of carbon dioxide is significantly prominent in terms of conversion and cyclohexanone selectivity. Moreover, the silica/alumina ratio was also found to be an important parameter to enhance the effectiveness of the catalyst as it exhibits a remarkable increase in phenol conversion from 20.6% to 98.4% as the support changes from only silica MCM‐41 to Al‐MCM‐41. A plausible mechanism for the hydrogenation of phenol to cyclohexanone over the palladium catalyst has been proposed. The proposition is validated by transition state calculations using density functional theory (DFT), which reveal that cyclohexanone is a favorable product and stabilized by <19 kcal mol−1 over cyclohexanol in scCO2 medium. Under similar reaction conditions, phenol hydrogenation was also carried out with rhodium, supported on Al‐MCM‐41. In contrast to the palladium catalyst, a mixture of cyclohexanone (57.8%) and cyclohexanol (42.2%) was formed. Detailed characterization by X‐ray diffraction and transmission electron microscopy confirmed the presence of metal nanoparticles (palladium and rhodium) between 10–20 nm. Both the catalysts exhibit strikingly different product distributions in solventless conditions compared to scCO2. This method can also be successfully applied to the other hydroxylated aromatic compounds.
A Highly Efficient Synthesis of a Naphthalenoid Histamine‐3 Antagonist
Authors: Ku Yi‐Yin , Grieme Tim , Pu Yu‐Ming , Bhatia Ashok V.
Published: July 2009

A highly efficient synthesis of the potent and selective histamine‐3 receptor antagonist 1A was accomplished in four chemical steps and a salt formation step in 36% overall yield from 6‐bromo‐2‐naphthalenol 9. The key features are a regioselective Suzuki coupling protocol for selective vinylation of 12 with potassium vinyltrifluoroborate in high yield (92%) with excellent regioselectivity (90:2) and a base‐catalyzed hydroamination reaction of 11 in an anti‐Markovnikov fashion under mild reaction conditions. An optimized copper‐catalyzed cross coupling reaction is used to incorporate the pyridazinone 4.
NETmix®, a new type of static mixer: Modeling, simulation, macromixing, and micromixing characterization
Authors: Laranjeira Paulo E. , Martins António A. , Lopes José Carlos B. , Dias Madalena M.
Published: July 2009

NETmix® is a new technology for static mixing based on a network of chambers connected by channels. The NETmix® model is the basis of a flow simulator coupled with chemical reaction used to characterize macro and micromixing in structured porous media. The chambers are modeled as perfectly mixing zones and the channels as plug flow perfect segregation zones. A segregation parameter is introduced as the ratio between the channels volume and the whole network volume. Different kinetics and reactants injection schemes can be implemented. Results show that the number of rows in the flow direction and the segregation parameter control both macro and micromixing, but the degree of micromixing is also controlled by the reactants injection scheme. The NETmix® model enables the systematic study of micromixing and macromixing for different network structures and reaction schemes, enabling the design of network structures to ensure the desired yield and selectivity. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Age and energy intake interact to modify cell stress pathways and stroke outcome
Authors: Arumugam Thiruma V. , Phillips Terry M. , Cheng Aiwu , Morrell Christopher H. , Mattson Mark P. , Wan Ruiqian
Published: July 2009

Objective

Age and excessive energy intake/obesity are risk factors for cerebrovascular disease, but it is not known if and how these factors affect the extent of brain damage and outcome in ischemic stroke. We therefore determined the interactions of age and energy intake on the outcome of ischemic brain injury, and elucidated the underlying mechanisms.

Methods

We utilized a novel microchip‐based immunoaffinity capillary electrophoresis technology to measure a panel of neurotrophic factors, cytokines, and cellular stress resistance proteins in brain tissue samples from young, middle‐aged, and old mice that had been maintained on control or energy‐restricted diets prior to middle cerebral artery occlusion and reperfusion.

Results

Mortality from focal ischemic stroke was increased with advancing age and reduced by an intermittent fasting (IF) diet. Brain damage and functional impairment were reduced by IF in young and middle‐aged mice, but not in old mice. The basal and poststroke levels of neurotrophic factors (brain‐derived neurotrophic factor and basic fibroblast growth factor), protein chaperones (heat shock protein 70 and glucose regulated protein 78), and the antioxidant enzyme heme oxygenase‐1 were decreased, whereas levels of inflammatory cytokines were increased in the cerebral cortex and striatum of old mice compared with younger mice. IF coordinately increased levels of protective proteins and decreased inflammatory cytokines in young, but not in old mice.

Interpretation

Reduction in dietary energy intake differentially modulates neurotrophic and inflammatory pathways to protect neurons against ischemic injury, and these beneficial effects of IF are compromised during aging, resulting in increased brain damage and poorer functional outcome. ANN NEUROL 2010;67:41–52
FT–NIR as a determination method for reinforcement of polymer nanocomposites
Authors: Laske Stephan , Kracalik Milan , Feuchter Michael , Pinter Gerald , Maier Günther , Märzinger Wolfgang , Haberkorn Michael , Langecker Günter Rüdiger
Published: July 2009

Layered silicates as nanoscale fillers have a great potential in improving polymer material properties. Depending on the composite structure (agglomerated, intercalated, or exfoliated) a significantly higher level of reinforcement of the virgin polymer can be achieved with a very small amount of filler. The morphology of the composites is usually characterized by XRD and microscopic methods (e.g., transmission electron microscopy). But the level of reinforcement of nanocomposites is not always proportional to morphology (delamination level of the silicate layers). A new approach for characterizing the material reinforcement level as a consequence of melt quality is to correlate the results of extensional rheometry (level of melt strength) with those of near infrared (NIR) spectroscopy. The advantage of the NIR technique is the suitability for in‐line implementation by using quartz based optics and optical fibers for the signal transfer from the measuring probe to the NIR spectrometer. The presented results show a direct correlation between the reinforcement level determined by rheotens measurements and the data analyzed from off‐line NIR measurements. The results of the chemometric analysis of the NIR data shows that this in‐line capable optical method provides quantitative information on the quality of the nanocomposite. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Morphology, biodegradability, mechanical, and thermal properties of nanocomposite films based on PLA and plasticized PLA
Authors: Ozkoc Guralp , Kemaloglu Sebnem
Published: July 2009

In this study, melt intercalation method is applied to prepare poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG)‐plasticized PLA nanocomposite films including 0, 3, and 5% organoclay (Cloisite 30B) using a laboratory scale compounder, which is connected to a microcast film device. To evaluate the nanomorphology and the dispersion state of the clays, X‐ray diffraction (XRD) and transmission electron microscopy (TEM) are conducted. Tensile tests are performed to characterize the mechanical behavior of the films. Biodegradation rate is determined by degradation tests in composting medium. Differential scanning calorimeter (DSC) is applied to observe the thermal behavior of the films. XRD and TEM show that the exfoliation predominantly occurrs in plasticized PLA nanocomposites, whereas unexfoliated agglomerates together with exfoliated clays are observed in the nonplasticized PLA. Tensile tests indicate that the addition of 3% clay to the neat‐PLA does not affect the strength; however, it enhances the modulus of the nanocomposites in comparison to neat‐PLA. Incorporation of 3% clay to the plasticized PLA improves the modulus with respect to PLA/PEG; on the other hand, the strain at break value is lowered ∼ 40%. The increase in the rate of biodegradation in composting medium is found as in the order of PLA > PLA/PEG > 3% Clay/PLA/PEG > 5% Clay/PLA/PEG > 3% Clay/PLA. DSC analysis shows that the addition of 3% clay to the neat PLA results in an increase in Tg. The addition of 20% PEG as a plasticizer to the neat‐PLA decreases Tg about 30°C, however incorporation of clays increases Tg by 4°C for the plasticized PLA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Residual monomer in superabsorbent polymers: Effects of the initiating system
Authors: Kabiri K. , Zohuriaan‐Mehr M. J. , Bouhendi H. , Jamshidi A. , Ahmad‐Khanbeigi F.
Published: July 2009

Minimized residual monomer is an essential requirement particularly in hygienic, pharmaceutical, and food packaging polymer products such as superabsorbent polymers (SAPs). The present article is the first non‐patent report on the study of a highly effective polymerization variable (e.g. initiator) on the residual monomer of SAPs based on partially neutralized acrylic acid. Two persulfate systems, i.e. ammonium persulfate (APS)/sodium metabisulfite (SMBS) and APS/tetramethyl ethylenediamine (TMEDA), were examined to initiate the free‐radical polymerization at room temperature. It was shown that chromatographically measured residual monomer and swelling capacity was strongly dependent on the type and concentration of the initiator. A kinetic model was also derived to describe the experimental results. Dissociation rate of initiation system was recognized to be a key factor to obtain a SAP with low residual monomer. It was found that, in aqueous solution polymerization, the effect of a slowly dissociating system such as APS/TMEDA on decreasing the residual monomer was much higher than that of a rapidly dissociating system like APS/SMBS. Under selected conditions, residual monomer could be reduced up to 5327 ± 138 and 1715 ± 44 ppm for APS/SMBS and APS/TMEDA initiating systems, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improvement of surface and moisture resistance of epoxy resins with fluorinated glycidyl ether
Authors: Wang Chengzhong , Zuo Yu
Published: July 2009

Laurylfluoro glycidyl ether (FGE) was synthesized by laurylfluoro‐1‐pentanol with epichlorohydrin, and confirmed by FTIR and 13C‐NMR. The surface properties, moisture absorption, and mechanical properties of the epoxy resins modified by different content of laurylfluoro glycidyl ether acted as mono functional thinner were investigated by X‐ray photoelectron spectroscopy (XPS), universal testing machine (UTM), dynamic mechanical thermal analyzer (DMTA), etc. The fluorine content at the surface of the modified resins were enriched greatly with the increase of the content of laurylfluoro glycidyl ether, and the hydrophobic property of the resins surface increased. When the FGE content was 10%, the fluorine content at the surface of the modified epoxy resin reached to 66% and the water contact angle was 102°. The equilibrium moisture content of the resin dropped by 30% when the content of FGE was 5%. The mechanical properties of the epoxy resins modified by FGE were improved while the thermal mechanical properties changed little at low content of FGE (less than 3%). Further increase of FGE content in the epoxy resins may result in decreases of the mechanical and thermal mechanical properties of the resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Properties and morphologies of elastomer blends modified with EPDM‐g‐poly[2‐dimethylamino ethylmethacrylate]
Authors: Botros Samir H. , Moustafa Ahmed F. , Essa Mohamed M.
Published: July 2009

The graft copolymerization of 2‐dimethylamino ethylmethacrylate (DMAEMA) onto ethylene propylene diene mononer rubber (EPDM) was carried out in toluene via solution polymerization technique at 70°C, using dibenzoyl peroxide as initiator. The synthesized EPDM rubber grafted with poly[DMAEMA] (EPDM‐g‐PDMAEMA) was characterized with 1H‐NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The EPDM‐g‐PDMAEMA was incorporated into EPDM/butadiene acrylonitrile rubber (EPDM/NBR) blend with different blend ratios, where the homogeneity of such blends was examined with scanning electron microscopy and DSC. The scanning electron micrographs illustrate improvement of the morphology of EPDM/NBR rubber blends as a result of incorporation of EPDM‐g‐PDMAEMA onto that blend. The DSC trace exhibits one glass transition temperature (Tg) for EPDM/NBR blend containing EPDM‐g‐PDMAEMA, indicating improvement of homogeneity. The physico‐mechanical properties after and before accelerated thermal aging of the homogeneous, and inhomogeneous EPDM/NBR vulcanizates with different blend ratios were investigated. The physico‐mechanical properties of all blend vulcanizates were improved after and before accelerated thermal aging, in presence of EPDM‐g‐PDMAEMA. Of all blend ratios under investigation EPDM/NBR (75/25) blend possesses the best physico‐mechanical properties together with the best (least) swelling (%) in brake fluid. Swelling behavior of the rubber blend vulcanizates in motor oil and toluene was also investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009