bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumour Size at Detection According to Different Measures of Mammographic Breast Density
Authors: Nickson Carolyn , Kavanagh Anne M
Published: October 2009

Objectives

Breast cancer prognosis is better for smaller tumours. Women with high breast density are at higher risk of breast cancer and have larger screen-detected and interval cancers in mammographic screening programmes. We assess which continuous measures of breast density are the strongest predictors of breast tumour size at detection and therefore the best measures to identify women who might benefit from more intensive mammographic screening or alternative screening strategies.

Setting and methods

We compared the association between breast density and tumour size for 1007 screen-detected and 341 interval cancers diagnosed in an Australian mammographic screening programme between 1994 and 1996, for three semi-automated continuous measures of breast density: per cent density, dense area and dense area adjusted for non-dense area.

Results

After adjustment for age, hormone therapy use, family history of breast cancer and mode of detection (screen-detected or interval cancers), all measures of breast density shared a similar positive and significant association with tumour size. For example, tumours increased in size with dense area from an estimated mean 2.2 mm larger in the second quintile (β = 2.2; 95% Cl 0.4–3.9, P < 0.001) to mean 6.6 mm larger in the highest decile of dense area (β = 6.6; 95% Cl 4.4–8.9, P < 0.001), when compared with first quintile of breast density.

Conclusions

Of the breast density measures assessed, either dense area or per cent density are suitable measures for identifying women who might benefit from more intensive mammographic screening or alternative screening strategies.
Personality Traits, Psychological Health, and the Workers' Compensation System
Authors: Wall Cindy L. , Morrissey Shirley A. , Ogloff James R.P.
Published: October 2009

This study explored the influence of personality traits on injured workers' interaction with workers' compensation systems. Data were collected from 89 participant claimants (males, 41; females 48, mean age = 45 years,SD= 10.67 years) at various levels of involvement with the workers' compensation system: previous claimants (n= 39), current claimants (n= 28), and nonclaimant workers (n= 22). Significant differences in personality traits were found between these groups of compensation claimants. Current compensation claimants displayed greater emotional instability and introversion compared with those less acutely involved in the compensation system. Current claimants also experienced clinically significant levels of symptoms of depression, anxiety, somatic complaints, and reported reduced social functioning, relative to previous and nonclaimants, respectively. Overall, subtle differences were found to exist in personality and psychological health between groups of workers at different levels of involvement with the workers' compensation system.
Genetic Factors Underlie Stability of Obsessive–Compulsive Symptoms
Authors: van Grootheest Daniël S. , Cath Daniëlle , Hottenga Jouke Jan , Beekman Aartjan T. , Boomsma Dorret I.
Published: October 2009

The contribution of genetic and environmental factors to the stability of obsessive–compulsive (OC) symptoms has not yet been established in adult population based samples. We obtained the Young Adult Self Report Obsessive–Compulsive Subscale in mono- and dizygotic twins from the population-based Netherlands Twin Register in 1991, 1995 and 1997 and the Padua Inventory Revised Abbreviated in 2002. Stability of OC symptoms was analyzed as a function of genetic and environmental components. Heritability of OC behavior was around 40% at each time-point, independent of the instrument used. OC behavior was moderately stable with correlations ranging between r = .2 (for 11-year intervals), .4 (for 4–5 year intervals) and .6 (for 2 year intervals). Genetic correlations across time were higher, varying between .4 and .9, indicating that the stability of OC symptoms is mainly due to stable genetic factors. This study showed a moderate heritability and stability for OC behavior in adults. Genetic stability across time is high.
A General Factor of Personality: Evidence from the HEXACO Model and a Measure of Trait Emotional Intelligence
Authors: Veselka Livia , Schermer Julie Aitken , Petrides K. V. , Cherkas Lynn F. , Spector Tim D. , Vernon Philip A.
Published: October 2009

The purpose of the present study was to determine if a general factor of personality (GFP) could be extracted from the six dimensions of the HEXACO model and four factors of trait emotional intelligence. Participants were 1,192 pairs of twins (666 MZ pairs, 526 DZ pairs) between the ages of 19 to 86 years, who completed the Trait Emotional Intelligence Questionnaire — Short Form and the HEXACO Personality Inventory — Revised. Principal components analysis yielded a strong GFP accounting for 33% of the variance, on which all variables with the exception of honesty-humility from the HEXACO showed moderate to large loadings. Behavioral genetic (BG) analyses revealed that individual differences in the GFP were entirely attributable to additive genetic and non-shared environmental factors — results that are in accord with previous BG analyses of a GFP. The present study adds to the body of evidence in support of a heritable GFP but an alternative perspective is also discussed.
Parental Alcoholism and Offspring Behavior Problems: Findings in Australian Children of Twins
Authors: Waldron Mary , Martin Nicholas G. , Heath Andrew C.
Published: October 2009

We examine the impact of rearing by an alcoholic parent on risk for child behavior problems using data on 2492 offspring drawn from two ongoing studies of children of female and male same- and opposite-sex twin pairs. Results of regression models predicting child behavior problems from parent and co-twin lifetime history of alcohol use disorder (AUD) provide support for genetic but not environmental transmission of externalizing and a measure of total problem behaviors. Results for internalizing behavior were inconclusive with respect to transmission of risk.
Twins Eye Study in Tasmania (TEST): Rationale and Methodology to Recruit and Examine Twins
Authors: Mackey David A. , MacKinnon Jane R. , Brown Shayne A. , Kearns Lisa S. , Ruddle Jonathan B. , Sanfilippo Paul G. , Sun Cong , Hammond Christopher J. , Young Terri L. , Martin Nicholas G. , Hewitt Alex W.
Published: October 2009

Visual impairment is a leading cause of morbidity and poor quality of life in our community. Unravelling the mechanisms underpinning important blinding diseases could allow preventative or curative steps to be implemented. Twin siblings provide a unique opportunity in biology to discover genes associated with numerous eye diseases and ocular biometry. Twins are particularly useful for quantitative trait analysis through genome-wide association and linkage studies. Although many studies involving twins rely on twin registries, we present our approach to the Twins Eye Study in Tasmania to provide insight into possible recruitment strategies, expected participation rates and potential examination strategies that can be considered by other researchers for similar studies. Five separate avenues for cohort recruitment were adopted: (1) piggy-backing existing studies where twins had been recruited, (2) utilizing the national twin registry, (3) word-of-mouth and local media publicity, (4) directly approaching schools, and finally (5) collaborating with other research groups studying twins.
Phenotypic and Discordant-Monozygotic Analyses of Stress and Perceived Social Support as Antecedents to or Sequelae of Risk for Depression
Authors: Coventry William L. , Medland Sarah E. , Wray Naomi R. , Thorsteinsson Einar B. , Heath Andrew C. , Byrne Brian
Published: October 2009

The associations between social support and depression, and between stress and depression have been the subject of considerable research, and although this has included longitudinal designs, these have rarely controlled for genetic effects that mediate these associations. The sample comprised 7,356 female and 4,882 male participants aged 18–95 from the Australian NHMRC Twin Registry (ATR). Of these, between 100 and 324 female pairs and between 41 and 169 male pairs, depending on the measure, were monozygotic (MZ) pairs discordant for depression. We use the co-twin control design in combination with prospective analyses to explore the association between a composite of predictors (perceived social support, stress, and support × stress) and depression. With familial effects included, both perceived support and stress were antecedents to, and sequelae of, depression, but no stress-buffering occurred. With familial effects controlled, stress was a sequela of a prior depressive episode, and neither lack of support nor stress were antecedents to depression, though their interaction approached significance for males. The male twin who later became depressed had previously reported lower perceived support in the face of multiple stressors compared to his co-twin who did not become depressed. We show that associations commonly observed with prospective designs are partly due to familial factors.
Spatial variability in ecological attributes of the seagrass Cymodocea nodosa
Authors: Mascaró Oriol , Oliva Silvia , Pérez Marta , Romero Javier
Published: October 2009

Assessment of ecosystem natural variability is a major goal in ecology, not only to better understand fluctuations, but also as a basis for distinguishing such natural variability from changes caused by human activities. We document here spatial variability of several Cymodocea nodosa attributes relevant to ecosystem functioning and indicative of ecosystem health at three localities near its upper and lower latitudinal distribution limits. At each locality, we chose three healthy and unaltered meadows, and, at each meadow, three sampling areas. The attributes measured were shoot density, biomass allocation to leaves and roots, shoot size, carbohydrate reserves, element content (C, N, P, S) and stable isotope ratios (δ13C, δ15N and δ34S). Geographical differences (among localities) accounted for between 65 and 90% of the total variability, while variability within localities (both between meadows and within meadows) accounted for substantial but lower contributions in most attributes. This suggests a relatively important degree of geographic plasticity in the attributes examined. Results presented here contribute to our basic knowledge of C. nodosa and its variability over large areas, which can be especially relevant for coastal monitoring and management programs.
New Methodology for Source Characterization in Pulse Velocity Testing
Authors: Tallavó Fernando , Cascante Giovanni , Pandey Mahesh D.
Published: October 2009

The pulse velocity test (PVT) is an ASTM standard for the measurement of compressional wave velocities in geomaterials. The PVT is based only on the first arrival of the wave. Full-waveform analysis can be used to measure the variation in geomaterial properties with frequency but requires the dynamic characteristics of the transducers. This paper presents a new methodology for the dynamic characterization of ultrasonic transmitters based on experimental and numerical results. Different types of excitation pulses (input signals) are used, and their theoretical Fourier spectra are computed. The methodology is demonstrated using a piezoelectric accelerometer to measure the frequency response function of an ultrasonic transmitter (UT) (50 kHz). The complex exponential method is used to extract the dynamic properties of the transmitter from transient time signals. Experimental results show that this methodology can be used for the dynamic characterization of ultrasonic transmitters. Results from finite element numerical simulations of wave propagation agree with laboratory results.
Tamales on the Fourth of July: The Transnational Parish of Coeneo, Michoacán
Authors: Murillo Luis E.
Published: October 2009

This article traces the significant yet largely unexplored experience of transnationalism in the lived religious experiences of Mexican and Mexican American Catholics by focusing on the parish as a central unit of analysis. Within this analysis, the parish unit is rethought as an analytical unit in two important regards. First, the way in which parish life in rural Mexico has been predominately conceptualized as one whose rhythm revolves around a traditional ritual calendar centered on community celebrations of particular religious holidays and localized votive devotions needs to be replaced. Based on research from an ongoing historical case study (1890-present) of a central Mexican parish, Nuestra Señora del Rosario in Coeneo, Michoacán, and on other parishes, the rhythm of parish life has clearly shifted to celebrations of marriages and baptisms. These religious celebrations of marriages and baptisms in Mexico have become the focal point of identity and community in this transnational Mexican and Mexican American experience. These sacraments of baptism and marriage have multiple meanings that not only include universal Catholic doctrines but also notions of family, community, and a particular appreciation for the sacralized landscape of their Mexican parish. Second, notions of parish boundaries as fixed and parish affiliation as singular must be reconsidered because many Mexicans and Mexican Americans living in the United States consider themselves to be active members in at least two parishes: one in Mexico and one or more in the United States.
The Bible, the First Amendment, and the Public Schools in Odessa, Texas
Authors: Chancey Mark A.
Published: October 2009

Bible courses in public schools are receiving a level of attention not witnessed in decades, and their increased numbers create greater potential for local conflicts and lawsuits over whether they promote religion and violate the First Amendment. Such courses are relatively understudied, and their contents and the paths by which schools decide to offer them are largely unknown. One district that has experienced both conflict and lawsuit over its Bible course is Ector County Independent School District in Odessa, Texas, where a 2005–2008 dispute pitted townspeople and national organizations against each other. This article uses the Odessa controversy as a case study to demonstrate how Bible courses provide a unique window into the confusion found at the intersection of American public education, the study of religion, and church-state relations. Drawing upon school district documents, recordings of school board meetings, journalistic accounts, legal documents, press releases, Bible curricula produced by the National Council on Bible Curriculum in Public Schools and the Bible Literacy Project, and course materials from district high schools, it traces the development of the conflict. It examines the role that appeals to the Establishment Clause and Free Exercise Clause played in the controversy, confusion over what is legally acceptable in public schools, particularly in regard to historicity issues, and the difficulty in developing a genuinely nonsectarian course. It contextualizes the Odessa debate within Christian Right efforts to influence public schools and larger American society, efforts often grounded in the claim that America is a Christian nation. Controversies such as Odessa's illustrate the tensions produced in American society by competing notions of religious freedom and American identity.
The International Social Turn: Unity and Brotherhood at the World's Parliament of Religions, Chicago, 1893
Authors: Kittelstrom Amy
Published: October 2009

When the World's Parliament of Religions convened at the Columbian Exposition at Chicago in 1893, it brought together delegates of Judaism, Buddhism, Hinduism, Jainism, Islam, and several varieties of Christianity. Recent critics of the event have noted that the overwhelmingly Protestant organizers imposed their own culturally specific views of what constitutes religion on the non-Christian participants. But the guiding refrain of the Parliament—the unity of God and the brotherhood of man—reflects not only the specifically Social Gospel theology of the Protestant organizers but also a much wider consensus on the proper character, scope, and function of religion in a modernizing, globalizing, secularizing world. Buddhists from Japan, Hindus and Jains from India, and Buddhists from Ceylon actively participated in this international turn toward social religion as a way of pursuing their own culturally specific claims of distinct national identity, while Jews and Catholics in the United States equally adeptly claimed ownership of this central rhetoric of social religion in order to penetrate the American cultural mainstream.
Review Essay: Religion, War, and the Meaning of America
Authors: Stout Harry S.
Published: October 2009

The norm of American national life is war. From colonial origins to the present, Americans have never seen a generation that was not preoccupied with wars, threats of wars, and military interventions on foreign soils. This is not something Americans—or American historians—are trained to think about. In American memory and mythology, the United States is, at heart, a nation of peace; it unleashes the quiver of war as a last resort and only when pushed. In like manner religion, especially what we now call evangelical Protestantism, has been a conspicuous presence in American wars from the seventeenth century to the present. American wars are sacred wars and American religion, with some notable exceptions, is martial at the very core of its being. The ties between war and religion are symbiotic and the two grew up inextricably intertwined.
Effects of Cyclic Strain and Growth Factors on Vascular Smooth Muscle Cell Responses
Authors: Kona Soujanya , Chellamuthu Prithiviraj , Xu Hao , Hills Seth R , Nguyen Kytai Truong
Published: October 2009

Under physiological and pathological conditions, vascular smooth muscle cells (SMC) are exposed to different biochemical factors and biomechanical forces. Previous studies pertaining to SMC responses have not investigated the effects of both factors on SMCs. Thus, in our research we investigated the combined effects of growth factors like Bfgf (basic fibroblast growth factor), TGF-β (transforming growth factor β) and PDGF (platelet-derived growth factor) along with physiological cyclic strain on SMC responses. Physiological cyclic strain (10% strain) significantly reduced SMC proliferation compared to static controls while addition of growth factors bFGF, TGF-β or PDGF-AB had a positive influence on SMC growth compared to strain alone. Microarray analysis of SMCs exposed to these growth factors and cyclic strain showed that several bioactive genes (vascular endothelial growth factor, epidermal growth factor receptor, etc.) were altered upon exposure. Further work involving biochemical and pathological cyclic strain stimulation will help us better understand the role of cyclic strain and growth factors in vascular functions and development of vascular disorders.
Deterministic Chaos and Fractal Complexity in the Dynamics of Cardiovascular Behavior: Perspectives on a New Frontier
Authors: Sharma Vijay
Published: October 2009

Physiological systems such as the cardiovascular system are capable of five kinds of behavior: equilibrium, periodicity, quasi-periodicity, deterministic chaos and random behavior. Systems adopt one or more these behaviors depending on the function they have evolved to perform. The emerging mathematical concepts of fractal mathematics and chaos theory are extending our ability to study physiological behavior. Fractal geometry is observed in the physical structure of pathways, networks and macroscopic structures such the vasculature and the His-Purkinje network of the heart. Fractal structure is also observed in processes in time, such as heart rate variability. Chaos theory describes the underlying dynamics of the system, and chaotic behavior is also observed at many levels, from effector molecules in the cell to heart function and blood pressure. This review discusses the role of fractal structure and chaos in the cardiovascular system at the level of the heart and blood vessels, and at the cellular level. Key functional consequences of these phenomena are highlighted, and a perspective provided on the possible evolutionary origins of chaotic behavior and fractal structure. The discussion is non-mathematical with an emphasis on the key underlying concepts.
Adult Congenital Heart Disease Investigated with Cardiac Catheterization Over A 20-Year Period
Authors: Giannoglou George D , Antoniadis Antonios P , Chatzizisis Yiannis S , Louridas George E
Published: October 2009

Background:

Recent advances in diagnosis and treatment have increased the life expectancy of patients with congenital heart disease.

Methods:

To investigate the prevalence of adult congenital heart disease (ACHD) in a large registry of patients over a 20-year period, we retrospectively assessed data of 14,012 males and 4,461 females who underwent clinically indicated cardiac catheterization from 1984 to 2003.

Results:

ACHD was recorded in 234 subjects aged from 18 to 66 years, [95 males (40.7%) and 139 females (59.3%)]. Females were more likely to present with ACHD than males (p<0.001). Atrial septal defect was the most common defect (43.3%) followed by partial anomalous pulmonary venous return (12.0%), pulmonary valve stenosis (11.3%) ventricular septal defect (8.0%), coarctation of aorta (5.5%) patent ductus arteriosus (4.0%) and Fallot’s tetralogy (3.3%). Atrial septal defect was more common in females (p<0.01), while pulmonary valve stenosis was more frequent in males (p<0.05). No difference across sexes was found in the other forms of ACHD. Females with ACHD were significantly older than males at the time of catheterization (median age 41 years, interquartile range 26 to 53 years vs. median age 35 years, interquartile range 22 to 48 years, p<0.05).

Conclusions:

In adulthood ACHD is found more commonly in females and is diagnosed later in life than in males. Atrial septal defect is the most prevalent form of ACHD and occurs most commonly in females.
Forbidden intervals
Authors: Foreman Matthew
Published: October 2009

Many classical statements of set theory are settled by the existence of generic elementary embeddings that are analogous the elementary embeddings posited by large cardinals. [2] The embeddings analogous to measurable cardinals are determined by uniform, κ-complete precipitous ideals on cardinals κ. Stronger embeddings, analogous to those originating from supercompact or huge cardinals are encoded by normal fine ideals on sets such as [κ]<λ or [κ]λ.

The embeddings generated from these ideals are limited in ways analogous to conventional large cardinals. Explicitly, if j: V → M is a generic elementary embedding with critical point κ and λ supnЄωjn(κ) and the forcing yielding j is λ-saturated then j“λ+ ∉ M. (See [2].)

Ideals that yield embeddings that are analogous to strongly compact cardinals have more puzzling behavior and the analogy is not as straightforward. Some natural ideal properties of this kind have been shown to be inconsistent:

Theorem 1 (Kunen). There is no ω2-saturated, countably complete uniform ideal on any cardinal in the interval [ℵω, ℵω).

Generic embeddings that arise from countably complete, ω2-saturated ideals have the property that sup . So the Kunen result is striking in that it apparently allows strong ideals to exist above the conventional large cardinal limitations. The main result of this paper is that it is consistent (relative to a huge cardinal) that such ideals exist.
Incompatible Ω-Complete Theories
Authors: Koellner Peter , Woodin W. Hugh
Published: October 2009

In 1985 the second author showed that if there is a proper class of measurable Woodin cardinals andandare generic extensions ofVsatisfying CH thenandagree on all Σ12-statements. In terms of the strong logic Ω-logic this can be reformulated by saying that under the above large cardinal assumption ZFC + CH is Ω-complete for Σ12. Moreover, CH is the unique Σ12-statement with this feature in the sense that any other Σ12-statement with this feature is Ω-equivalent to CH over ZFC. It is natural to look for other strengthenings of ZFC that have an even greater degree of Ω-completeness. For example, one can ask for recursively enumerable axiomsAsuch that relative to large cardinal axioms ZFC +Ais Ω-complete for all of third-order arithmetic. Going further, for each specifiable segmentVλof the universe of sets (for example, one might takeVλto be the least level that satisfies there is a proper class of huge cardinals), one can ask for recursively enumerable axiomsAsuch that relative to large cardinal axioms ZFC +Ais Ω-complete for the theory ofVλ. If such theories exist, extend one another, and are unique in the sense that any other such theoryBwith the same level of Ω-completeness asAis actually Ω-equivalent toAover ZFC, then this would show that there is a unique Ω-complete picture of the successive fragments of the universe of sets and it would make for a very strong case for axioms complementing large cardinal axioms. In this paper we show that uniqueness must fail. In particular, we show that if there is one such theory that Ω-implies CH then there is another that Ω-implies ¬-CH.
Canonical rules
Authors: Jeřábek Emil
Published: October 2009

We develop canonical rules capable of axiomatizing all systems of multiple-conclusion rules overK4 orIPC, by extension of the method of canonical formulas by Zakharyaschev [37]. We use the framework to give an alternative proof of the known analysis of admissible rules in basic transitive logics, which additionally yields the following dichotomy: any canonical rule is either admissible in the logic, or it is equivalent to an assumption-free rule. Other applications of canonical rules include a generalization of the Blok–Esakia theorem and the theory of modal companions to systems of multiple-conclusion rules or (unitary structural global) consequence relations, and a characterization of splittings in the lattices of consequence relations over monomodal or superintuitionistic logics with the finite model property.
Approachability at the second successor of a singular cardinal
Authors: Gitik Moti , Krueger John
Published: October 2009

We prove that if μ is a regular cardinal and ℙ is a μ-centered forcing poset, then ℙ forces that (I[μ++[)V generates I[μ++] modulo clubs. Using this result, we construct models in which the approachability property fails at the successor of a singular cardinal. We also construct models in which the properties of being internally club and internally approachable are distinct for sets of size the successor of a singular cardinal.
Promptness does not imply superlow cuppability
Authors: Diamondstone David
Published: October 2009

A classical theorem in computability is that every promptly simple set can be cupped in the Turing degrees to some complete set by a low c.e. set. A related question due to A. Nies is whether every promptly simple set can be cupped by a superlow c.e. set, i.e. one whose Turing jump is truth-table reducible to the halting problem ∅′. A negative answer to this question is provided by giving an explicit construction of a promptly simple set that is not superlow cuppable. This problem relates to effective randomness and various lowness notions.
Independently axiomatizable ℒω1,ω theories
Authors: Hjorth Greg , Souldatos Ioannis A.
Published: October 2009

In partial answer to a question posed by Arnie Miller [4] and X. Caicedo [2] we obtain sufficient conditions for an ℒω1,ω theory to have an independent axiomatization. As a consequence we obtain two corollaries: The first, assuming Vaught's Conjecture, every ℒω1,ω theory in a countable language has an independent axiomatization. The second, this time outright in ZFC, every intersection of a family of Borel sets can be formed as the intersection of a family of independent Borel sets.
Successors of singular cardinals and coloring theorems II
Authors: Eisworth Todd , Shelah Saharon
Published: October 2009

In this paper, we investigate the extent to which techniques used in [10], [2], and [3]—developed to prove coloring theorems at successors of singular cardinals of uncountable cofinality—can be extended to cover the countable cofinality case.
On computable self-embeddings of computable linear orderings
Authors: Downey Rodney G. , Kastermans Bart , Lempp Steffen
Published: October 2009

We solve a longstanding question of Rosenstein, and make progress toward solving a long-standing open problem in the area of computable linear orderings by showing that every computableη-like linear ordering without an infinite stronglyη-like interval has a computable copy without nontrivial computable self-embedding.

The precise characterization of those computable linear orderings which have computable copies without nontrivial computable self-embedding remains open.
First-order characterization of the radical of a finite group
Authors: Wilson John S.
Published: October 2009

It is shown that there is a formula σ(g) in the first-order language of group theory with the following property: for every finite group G, the largest soluble normal subgroup of G consists precisely of the elements g of G such that σ(g) holds.
Rotating disk electrode study of electrocatalytic oxidation of ascorbate at Prussian blue modified electrode
Authors: Araminaitė Rūta , Garjonytė Rasa , Malinauskas Albertas
Published: October 2009

Electrooxidation of ascorbate has been studied with the use of a rotating disk electrode. The results obtained show an efficient electrocatalytic oxidation of ascorbate at the Prussian blue (PB) modified electrode to proceed in solutions of pH 5.5 and 7.3. Depending on solution pH, the onset potential for ascorbate electrooxidation at PB modified electrode appears shifted by 0.1–0.2 V to lower values, as compared to an unmodified glassy carbon electrode. Within the electrode potential window of 0.3 to 0.5 V vs. Ag/AgCl, and electrode rotation velocity of 50–2000 rpm, the catalytic current obeys Koutecky-Levich equation at a submillimolar ascorbate concentration. Kinetic current densities, obtained from the data treatment, are higher for a pH 5.5 solution, and also at higher electrode potential.
Effects of doping with CeO2 and calcination temperature on physicochemical properties of the NiO/Al2O3 system
Authors: Shaheen Waleed , El-Hendawy A.
Published: October 2009

The effects of doping with CeO2 and calcination temperature on the physicochemical properties of the NiO/Al2O3 system have been investigated using DTA, XRD, nitrogen adsorption measurements at −196°C and decomposition of H2O2 at 30–50°C. The pure and variously doped solids were subjected to heat treatment at 300, 400, 700, 900 and 1000°C. The results revealed that the specific surface areas increased with increasing calcination temperature from 300 to 400°C and with doping of the system with CeO2. The pure and variously doped solids calcined at 300 and 400°C consisted of poorly crystalline NiO dispersed on γ-Al2O3. Heating at 700°C resulted in formation of well crystalline NiO and γ-Al2O3 phases beside CeO2 for the doped solids. Crystalline NiAl2O4 phase was formed starting from 900°C. The degree of crystallinity of NiAl2O4 increased with increasing the calcination temperature from 900 to 1000°C. An opposite effect was observed upon doping with CeO2. The NiO/Al2O3 system calcined at 300 and 400°C has catalytic activity higher than individual NiO obtained at the same calcination temperatures. The catalytic activity of NiO/Al2O3 system increased, progressively, with increasing the amount of CeO2 dopant and decreased with increasing the calcination temperature.
Synthesis of hydroxyapatite by using calcium carbonate and phosphoric acid in various water-ethanol solvent systems
Authors: Engin Arzu , Girgin İsmail
Published: October 2009

The purpose of the present study is to synthesize hydroxyapatite by using CaCO3 and H3PO4 in various water-ethanol solvent systems. It was observed from experiments that formation of ammonium phosphate compounds hindered the formation of calcium phosphates in ethanol medium. Although the reactivity was better in aqueous medium, the carbonate contents of the products obtained were above 8.5%. Best results with a carbonate content as low as 3.82% was obtained in 50% ethanol containing mixed-aqueous medium at 80°C and the FTIR analysis showed that the product was a carbonated apatite with a calculated composition of 14CaO·4.2P2O5·CO3·7.2H2O. The amorphous and porous phosphate compound obtained with a BET surface area of 106.6 m2 g−1 seems to be useful as adsorbent in wastewater treatment. Upon sintering of the amorphous product at 750°C, crystalline hydroxyapatite with a BET surface area of 25.9 m2 g−1 is obtained that may be used in biomedical applications.
Miniaturization of flow-through generation cells for electrochemical hydride generation in AAS
Authors: Hraníček J. , Červený V. , Rychlovský P.
Published: October 2009

The construction and optimization of five new types of miniaturized flow-through electrolytic cells with lead cathode and platinum anode for electrochemical hydride generation in atomic absorption spectrometry (HG-QFAAS) were achieved during this research study. The ion-exchange membrane was not part of these cells and only one carrying electrolyte for both electrode chambers was used. Hydride generation efficiency achieved was either comparable or higher than the one recorded for the classic thin-layer generation cell. The inner volume of the cathode chamber was reduced to a quarter of the classic thin-layer flow-through cell. Compared to the commonly used thin-layer flow-through cell, higher sensitivity (7.32×103 dm3 µg−1) and better limit of detection (0.32 µg dm−3) were obtained for selenium determination using two of these new generators.
Activity and kinetics studies of yeast alcohol dehydrogenase in a reverse micelle formulated from functional surfactants
Authors: Zhang Yun , Huang Xirong , Ji Guanglei , Li Ying , Liu Weifeng , Qu Yinbo
Published: October 2009

Yeast alcohol dehydrogenase (YADH) showed substantial decrease in its catalytic activity due to the strong electrostatic interaction between the head groups of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and YADH in AOT reverse micelles. However, the catalytic activity of YADH in a nonionic reverse micellar interface (GGDE/TX-100) obtained from a functional nonionic surfactant N-gluconyl glutamic acid didecyl ester (GGDE) and Triton X-100 (TX-100) was higher than that in AOT reverse micelle under the respective optimum conditions. A comparison of the kinetic parameters showed that the turnover number kcat in GGDE/TX-100 reverse micelle was 1.4 times as large as that in AOT reverse micelle, but the Michaelis constants in AOT reverse micelle for ethanol K mB was twice and for coenzyme NAD+ K mA was 5 times higher than their counterparts in GGDE/TX-100 reverse micelle. For the conversion of ethanol, the smaller K mB and larger kcat in GGDE/TX-100 reverse micelle resulted in higher catalytic efficiency kcat/K mB. The stability of YADH in GGDE/TX-100 reverse micelle was also found to be better than that in AOT reverse micelle. They were mainly attributed to the absence of electric charge on the head groups of GGDE and TX-100 in the GGDE/TX-100 reverse micelle.
Synthesis of novel mesoporous Al2O3 microspheres with flower-like structure
Authors: Liu Huiping , Lu Guanzhong , Guo Yun , Wang Yanqin , Guo Yanglong
Published: October 2009

Using glucose as a structuring additive and aluminium nitrate as the Al precursor, a novel kind of mesoporous Al2O3 microspheres with flower-like structure were synthesized hydrothermally at 180°C for 20 h. When the synthesis temperature was lowered to 140°C, the carambola-like Al2O3 can be synthesized. This approach is convenient and simple, and flower-like Ce-Al2O3 and La-Al2O3 spheres have also been prepared in this way. It may be applied to synthesize other metal oxides when suitable precursor salts are used. From an analysis of the experimental results, a mechanism for the formation of the flower-like Al2O3 spheres has been proposed and discussed.
Investigation of electrical properties of PANI/chalcogenide junctions
Authors: Shaktawat Vinodini , Patidar Dinesh , Sharma Kananbala , Saxena Narendra , Sharma Thansewar.
Published: October 2009

Pure Polyaniline (EB) and Polyaniline doped with different protonic acids (ESs) were chemically synthesized using ammonium peroxydisulphate (APS) as an oxidant. Junctions have been prepared by evaporating chalcogenide materials (ZnSe, CdSe) on conducting polyaniline (EB & ESs) pellets using a vacuum evaporation technique. I–V characteristics of junctions have been studied at room temperature using the Keithley electrometer 6517A. I–V measurements show the rectification effect. A junction of ES[PO43−] may be preferred over the other junctions due to its low ideality factor and maximum rectification ratio.
Use of the sulfide minerals pyrite and chalcopyrite as electrochemical sensors in non-aqueous solutions. The potentiometric titration of weak acids in alcohols
Authors: Mihajlović Ljiljana , Nikolić-Mandić Snežana , Vukanović Branislav , Mihajlović Ranđel
Published: October 2009

Natural monocrystalline pyrite and chalcopyrite were examined as new indicator electrodes for the potentiometric titration of weak acids in tert-butanol and iso-propanol. The electrodes investigated demonstrated a linear dynamic response for p-toluenesulfonic acid concentrations in the range from 0.1 to 0.001 M, with a Nernstian slope of 48 mV per decade for pyrite in tert-butanol. Sodium methylate, potassium hydroxide and tetrabutylammonium hydroxide (TBAH) proved to be suitable titrating agents. The response time was less than 12 s and the lifetime of the electrodes was higher than 1 year. The advantages of the electrodes are long-term stability, rapid response, reproducibility, easy preparation and low cost.
Polarized light spectroscopy of azobenzene or disperse red 1 with Mn12 single-molecule magnets in PMMA film hybrid materials
Authors: Akitsu Takashiro , Ishioka Chiaki , Itoh Tsubasa
Published: October 2009

A series of organic/inorganic hybrid materials containing the single-molecule magnet [Mn12(CH3COO)16(H2O)4O12]·2CH3COOH·4H2O with the photochromic compounds azobenzene or disperse red 1 cast into polymethyl methacrylate films was prepared. To understand the photomodulation of analogous mixtures’ AC susceptibility, we investigated the molecular alignment based on Weigert’s effect accompanying cycles of cis-trans photoisomerization by alternate irradiations with polarized UV and visible light. Polarized electronic spectra of the hybrid materials demonstrated gradually increasing anisotropy. These features suggest interactions between photochromic compounds and the Mn12 complex in polymethyl methacrylate.
Cloud point extraction-preconcentration and flame atomic absorption spectrometric determination of low levels of zinc in water and blood serum samples
Authors: Shokrollahi Ardeshir , Shamsipur Mojtaba , Jalali Fahimeh , Nomani Hamid
Published: October 2009

A simple, sensitive and selective flotation method is described for the preconcentration and atomic absorption spectrometric determination of zinc ion in water and blood samples. At a solution pH of 5.2, 4-(2-pyridylazo-resorcinol) and Triton X-114 were used as hydrophobic ligand and non-ionic surfactant, respectively. The chemical variables affecting the preconcentration process were optimized. Under the optimized experimental conditions, the selective preconcentration and determination of as low zinc concentration as 6.5 µg L−1 can be made. The proposed method was successfully applied to the preconcentration and low-level determination of zinc in different water and blood serum samples.
Acid-base behaviour of sanguinarine and dihydrosanguinarine
Authors: Absolínová Helena , Jančář Luděk , Jančářová Irena , Vičar Jaroslav , Kubáň Vlastimil
Published: October 2009

Acid-base and optical properties of sanguinarine and dihydrosanguinarine were studied in the presence of HCl, HNO3, H2SO4, H3PO4, CAPSO and acetic acid (HAc) of different concentrations and their mixtures. The equilibrium constants pKR+ of the transition reaction between an iminium cation Q+ of sanguinarine and its uncharged QOH (pseudo-base, 6-hydroxy-dihydroderivative) form were calculated. A numerical interpretation of the A-pH curves by a SQUAD-G computer program was used. Remarkable shifts of formation parts of absorbance-pH (A-pH) curves to alkaline medium were observed. The shifts depend on the type and concentration of inert electrolyte (the most remarkable for HNO3 and HCl). The corresponding pKR+ values ranged from 7.21 to 8.16 in the same manner (ΔpKR+ = 0.81 and 0.73 for HNO3 and HCl, respectively). The priority effect of ionic species and ionic strength was confirmed in the presence of NaCl and KCl. The strength of interaction of SA with bioactive compounds (i.e. receptors, transport proteins, nucleic acids etc.) may be affected because of the observed influence of both cations and anions of the inert electrolytes.
Modified silica surface by phenylboronic acid derivatives as effective sugar sensor
Authors: Kurczewska Joanna , Schroeder Grzegorz
Published: October 2009

Silica surface was modified with phenylboronic acid derivatives. The structures of the functionalized supports were characterized by FT-IR spectroscopy, 13C CP/MAS NMR spectrometry, elemental and thermogravimetric analysis. The solid supports were effectively applied as artificial receptors for sugars in aqueous solutions. Alizarin Red S. (ARS) was used to detect colour change upon carbohydrate (sugar) binding. The association constants of the supports studied-ARS complex and the functionalized silica-sugar (glucose) complex were calculated. The parameters obtained were comparable with those for the phenylboronic acids used for the silica gel modification. The competitive binding of the functionalized silica surface with ARS and sugar were studied by UV/VIS measurements.
“Bubble Bunch” phenomenon in operation of a bubble column
Authors: Bastani Dariush , Baghaei Ali , Sarrafi Amir
Published: October 2009

While studying the operation of a rectangular bubble column in laboratory scale, it was observed that under certain circumstances tiny bubbles attach to larger bubbles without causing them to coalesce. In other words, bubbles with large diameters (d > 5 mm) swept tiny bubbles (d
High surface area nano-sized La0.6Ca0.4MnO3 perovskite powder prepared by low temperature pyrolysis of a modified citrate gel
Authors: Soleymani Meysam , Moheb Ahmad , Joudaki Ezatolah
Published: October 2009

Single phase nanocrystalline La0.6Ca0.4MnO3 powder was synthesized by both the usual and a modified citrate gel precursor method, and the effects on the formation of homogeneous nano-sized powder with a perovskite structure were investigated. In the modified method, single phase La0.6Ca0.4MnO3 powder with an average particle size of 17.2 nm was obtained when the powder was pyrolyzed at 520°C for 2 h. Its specific surface area was 40.7 m2 g−1, about 4-fold larger than that of powder made by the usual citrate gel method.
Temperature-induced phase transition; Polymorphism in BP2 SAMs on Au(111)
Authors: Azzam Waleed
Published: October 2009

Self-assembled monolayers (SAMs) of ω-(4′-methylbiphenyl-4-yl)ethanethiol (CH3(C6H4)2(CH2)2SH, BP2) prepared at different temperatures on Au(111) substrates were investigated using scanning tunneling microscopy (STM). Also, the effect of the incubation time of the gold substrate in the thiol solution was examined. The STM results showed that samples prepared at room temperature were significantly different from those prepared at elevated temperatures in their surface morphology, space group and size of unit cell. The micrographs of samples prepared at higher temperatures revealed a pronounced and progressive increase in the size of the well-known etch-pits at the expense of their density with increasing preparation temperature (but the increase did not continue for SAMs prepared at 348 K). The average domain size was found to increase significantly with increasing preparation temperature. In addition, polymorphism was observed in BP2 SAMs at all investigated temperatures. This study has demonstrated that solution temperature and incubation time are key factors controlling the two-dimensional SAM structure of BP2 molecules.
Synthesis, structures, and spectroscopic properties of copper(I) complexes bearing 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine and 1,2-bis(diphenylphosphino)ethane ligands
Authors: Chi Shao-Ming , Wang Yu-Fei , Gan Xin , Wang De-Hui , Fu Wen-Fu
Published: October 2009

A new ligand napaa (napaa = 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine) and its two dinuclear copper(I) complexes, Cu2(napaa)(dppe)2(ClO4)2 (1) and Cu2(napaa)(PPh3)4(BF4)2 (2) (dppe = 1,2-bis(diphenylphosphino)ethane) and PPh3 = triphenylphosphine) were synthesized and characterized, and the structure of 1 was determined by X-ray crystal analysis. Each copper atom in 1 has a distorted tetrahedral geometry in which the metal center is associated to napaa and dppe ligands displaying chelating coordination modes and the naphthyridine rings of napaa are almost coplanar. The two complexes exhibit similar electronic absorption spectra with λmax at about 366 nm, which can be tentatively assigned to metal-to-ligand charge-transfer (MLCT) transition. The assignment was further supported by density functional theory (DFT) calculations.
Two charge-transfer complex spectrophotometric methods for the determination of sulpiride in pharmaceutical formulations
Authors: Zayed Sayed
Published: October 2009

Two simple, rapid, accurate and sensitive spectrophotometric methods are described for the determination of sulpiride. They are based on charge transfer complexation between the drug as n-electron donor and p-chloranilic acid as π acceptor or iodine as σ-acceptor. These give highly coloured complexes with absorption maxima at 518 and 363, 294 nm, respectively. Beer’s law linear ranges were 13.7–341.4 and 1.7–20.5 µg mL−1 for the p-chloranilic acid and iodine methods. The methods were successfully applied to the determination of the drug in Dogmatil® Fort tablets and the results compared with the official method. The complex association constants and standard free energy changes were calculated using Benesi-Hildebrand plots.
QSPR modelling of the octanol/water partition coefficient of organometallic substances by optimal SMILES-based descriptors
Authors: Toropov Andrey , Toropova Alla , Benfenati Emilio
Published: October 2009

Usually, QSPR is not used to model organometallic compounds. We have modeled the octanol/water partition coefficient for organometallic compounds of Na, K, Ca, Cu, Fe, Zn, Ni, As, and Hg by optimal descriptors calculated with simplified molecular input line entry system (SMILES) notations. The best model is characterized by the following statistics: n=54, r2=0.9807, s=0.677, F=2636 (training set); n=26, r2=0.9693, s=0.969, F=759 (test set). Empirical criteria for the definition of the applicability domain for these models are discussed.
The study of cyclooctene oxidation with molecular oxygen catalyzed by VSi2
Authors: Makota Oksana , Trach Yuriy , Leboda Roman , Skubiszewska-Zięba Jadwiga
Published: October 2009

The catalytic effect of VSi2 on initial stages of the liquid-phase oxidation of cyclooctene by molecular oxygen was studied. The vanadium disilicide influences on the oxidation process in the presence of hydroperoxide. VSi2 takes part in a radical formation stage by catalysis of hydroperoxide decomposition reaction. The catalyst was investigated before and after reaction using FTIR spectroscopy. From the data obtained, the kinetic model of the catalytic oxidation process was proposed and the equation for the reaction rate was derived. The equation has described all observed dependences of reaction rate on the concentration of reactants and content of catalyst.