bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Bazedoxifene on BMD and Bone Turnover in Postmenopausal Women: 2-Yr Results of a Randomized, Double-Blind, Placebo-, and Active-Controlled Study
Authors: Miller Paul D , Chines Arkadi A , Christiansen Claus , Hoeck Hans C , Kendler David L , Lewiecki E Michael , Woodson Grattan , Levine Amy B , Constantine Ginger , Delmas Pierre D
Published: December 2007

Osteoporosis is an increasingly common health concern in postmenopausal women. In a 2-yr phase III study, bazedoxifene prevented bone loss, reduced bone turnover, and was well tolerated in early postmenopausal women with normal or low BMD.

Introduction: Bazedoxifene is a novel selective estrogen receptor modulator that has increased BMD and bone strength in experimental models, without stimulating breast or uterus. This 24-mo, randomized, double-blind study assessed the efficacy and safety of three doses of bazedoxifene compared with placebo and raloxifene in the prevention of postmenopausal osteoporosis.

Materials and Methods: Healthy postmenopausal women with a BMD T-score at the lumbar spine or femoral neck between –1.0 and −2.5 or clinical risk factors for osteoporosis were randomly assigned to one of five groups: bazedoxifene 10, 20, or 40 mg/d, placebo, or raloxifene 60 mg/d. All women received elemental calcium. Efficacy outcomes included changes from baseline through 24 mo in BMD of the lumbar spine, hip, femoral neck, and femoral trochanter and biomarkers of bone metabolism.

Results: The intent-to-treat population included 1434 women (mean age, 58 yr; mean time from last menstrual period, 11 yr). All doses of bazedoxifene and raloxifene prevented bone loss, whereas in the placebo group, there was significant loss of BMD at all skeletal sites. Mean differences in percent change in lumbar spine BMD from baseline to 24 mo relative to placebo were 1.08 ± 0.28%, 1.41 ± 0.28%, 1.49 ± 0.28%, and 1.49 ± 0.28% for 10, 20, and 40 mg bazedoxifene and 60 mg raloxifene, respectively (p < 0.001 for all comparisons). Comparable BMD responses were observed at other body sites. Significant and comparable decreases in serum osteocalcin and C-telopeptide levels from baseline and relative to placebo with active treatment were observed as early as 3 mo and were sustained through study conclusion (p < 0.001). Overall incidences of adverse events, serious adverse events, and discontinuations caused by adverse events were similar between groups. The most common adverse events included headache, infection, arthralgia, pain, hot flush, and back pain.

Conclusions: Treatment with bazedoxifene prevented bone loss and reduced bone turnover equally as well as raloxifene and was generally well tolerated in postmenopausal women with normal/low BMD.
Simultaneous Assessment of Endothelial Function, Nitric Oxide Synthase Activity, Nitric Oxide–Mediated Signaling, and Oxidative Stress in Individuals with and without Hypercholesterolemia
Authors: Maas Renke , Schwedhelm Edzard , Kahl Lydia , Li Huige , Benndorf Ralf , Lüneburg Nicole , Förstermann Ulrich , Böger Rainer H
Published: December 2007

Background: Endothelial function is impaired in hypercholesterolemia and atherosclerosis. Based on mostly indirect evidence, this impairment is attributed to reduced synthesis or impaired biological activity of endothelium-derived nitric oxide (NO). It was the aim of this study to directly estimate and compare whole-body NO production in normo- and hypercholesterolemia by applying a nonradioactive stable isotope dilution technique in vivo.

Methods: We enrolled 12 normocholesterolemic and 24 hypercholesterolemic volunteers who were all clinically healthy. To assess whole-body NO synthesis, we intravenously administered l-[guanidino-(15N2)]-arginine and determined the urinary excretion of 15N-labeled nitrate, the specific end product of NO oxidation in humans, by use of gas chromatography-mass spectrometry. In addition, we measured flow-mediated vasodilation (FMD) of the brachial artery, expression of endothelial NOS (eNOS) in platelets, plasma concentration of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), and urinary excretion of 8-isoprostaglandin F2α (8-iso-PGF2α).

Results: After infusion of l-[guanidino-(15N2)]-arginine, cumulative excretion of 15N-labeled-nitrate during 48 h was 40% [95% CI 15%–66%] lower in hypercholesterolemic than normocholesterolemic volunteers [mean 9.2 (SE 0.8) μmol vs 15.4 (2.3) μmol/l, P = 0.003]. FMD was on average 36% [4%–67%] lower in hypercholesterolemic than normocholesterolemic volunteers [6.3 (4.0)% vs 9.4 (4.6)%, P = 0.027]. Normalized expression of NOS protein in platelets was also significantly lower in hypercholesterolemic volunteers, whereas there were no significant differences in plasma ADMA concentration or urinary excretion of 8-iso-PGF2α between the 2 groups.

Conclusions: This study provides direct evidence for a decreased whole body NO synthesis rate in healthy people with hypercholesterolemia.
Hyperhomocysteinemia, DNA methylation and vascular disease
Authors: Jamaluddin Md S. , Yang Xiaofeng , Wang Hong
Published: December 2007

Hyperhomocysteinemia (HHcy) has been established as a potent independent risk factor for cardiovascular disease (CVD) and the underlying mechanism is largely unknown. We were the first to propose that hypomethylation is the key biochemical mechanism by which homocysteine (Hcy) inhibits endothelial cell (EC) growth. We reported that clinically relevant concentrations of Hcy (10–50 μmol/L) exerts highly selective inhibitory effects on cyclin A transcription and EC growth through a hypomethylation related mechanism, which blocks cell cycle progression and endothelium regeneration. Recently, we demonstrated that Hcy reduces DNA methyltransferase 1 (DNMT1) activity and demethylates cyclin A promoter leading to cyclin A chromatin remodeling. We found that adenovirus-transduced

Clin Chem Lab Med 2007;45:1660–6.
Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
Authors: Herrmann Wolfgang , Herrmann Markus , Joseph Jacob , Tyagi Suresh C.
Published: December 2007

Chronic heart failure (CHF) is a major public health problem causing considerable morbidity and mortality. Recently, plasma homocysteine (HCY) has been suggested to be significantly increased in CHF patients. This article reviews the relation between hyperhomocysteinemia (HHCY) and CHF. Clinical data indicate that HHCY is associated with an increased incidence, as well as severity, of CHF. In addition, HCY correlates with brain natriuretic peptide (BNP), a modern biochemical marker of CHF, which is used for diagnosis, treatment guidance and risk assessment. Animal studies showed that experimental HHCY induces systolic and diastolic dysfunction, as well as an increased BNP expression. Moreover, hyperhomocysteinemic animals exhibit an adverse cardiac remodeling characterized by accumulation of interstitial and perivascular collagen. In vitro superfusion experiments with increasing concentrations of HCY in the superfusion medium stimulated myocardial BNP release independent from myocardial wall stress. Thus, clinical and experimental data underline a correlation between HHCY and BNP supporting the role of HHCY as a causal factor for CHF. The mechanisms leading from an elevated HCY level to reduced pump function and adverse cardiac remodeling are a matter of speculation. Existing data indicate that direct effects of HCY on the myocardium, as well as nitric oxide independent vascular effects, are involved. Preliminary data from small intervention trials have initiated the speculation that HCY lowering therapy by micronutrients may improve clinical as well as laboratory markers of CHF.

In conclusion, HHCY might be a potential etiological factor in CHF. Future studies need to explore the pathomechanisms of HHCY in CHF. Moreover, larger intervention trials are needed to clarify whether modification of plasma HCY by B-vitamin supplementation improves the clinical outcome in CHF patients.

Clin Chem Lab Med 2007;45:1633–44.
Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
Authors: Obeid Rima , Herrmann Wolfgang
Published: December 2007

Clin Chem Lab Med 2007;45:1746–50.
Impressões sobre o teste rápido para o HIV entre usuários de drogas injetáveis no Brasil
Authors: Telles-Dias PR , Westman S , Fernandez AE , Sanchez M
Published: December 2007

OBJETIVO: Descrever as impressões, experiências, conhecimentos, crenças e a receptividade de usuários de drogas injetáveis para participar das estratégias de testagem rápida para HIV. MÉTODOS: Estudo qualitativo exploratório foi conduzido entre usuários de drogas injetáveis, de dezembro de 2003 a fevereiro de 2004, em cinco cidades brasileiras, localizadas em quatro regiões do País. Um roteiro de entrevista semi-estruturado contendo questões fechadas e abertas foi usado para avaliar percepções desses usuários sobre procedimentos e formas alternativas de acesso e testagem. Foram realizadas 106 entrevistas, aproximadamente 26 por região. RESULTADOS: Características da população estudada, opiniões sobre o teste rápido e preferências por usar amostras de sangue ou saliva foram apresentadas junto com as vantagens e desvantagens associadas a cada opção. Os resultados mostraram a viabilidade do uso de testes rápidos entre usuários de drogas injetáveis e o interesse deles quanto à utilização destes métodos, especialmente se puderem ser equacionadas questões relacionadas à confidencialidade e confiabilidade dos testes. CONCLUSÕES: Os resultados indicam que os testes rápidos para HIV seriam bem recebidos por essa população. Esses testes podem ser considerados uma ferramenta valiosa, ao permitir que mais usuários de drogas injetáveis conheçam sua sorologia para o HIV e possam ser referidos para tratamento, como subsidiar a melhoria das estratégias de testagem entre usuários de drogas injetáveis.
Activin Alters the Kinetics of Endoderm Induction in Embryonic Stem Cells Cultured on Collagen Gels
Authors: Parashurama Natesh , Nahmias Yaakov , Cho Cheul H. , van Poll Daan , Tilles Arno W. , Berthiaume François , Yarmush Martin L.
Published: December 2007

Embryonic stem cell-derived endoderm is critical for the development of cellular therapies for the treatment of disease such as diabetes, liver cirrhosis, or pulmonary emphysema. Here, we describe a novel approach to induce endoderm from mouse embryonic stem (mES) cells using fibronectin-coated collagen gels. This technique results in a homogeneous endoderm-like cell population, demonstrating endoderm-specific gene and protein expression, which remains committed following in vivo transplantation. In this system, activin, normally an endoderm inducer, caused an 80% decrease in the Foxa2-positive endoderm fraction, whereas follistatin increased the Foxa2-positive endoderm fraction to 78%. Our work suggests that activin delays the induction of endoderm through its transient precursors, the epiblast and mesendoderm. Long-term differentiation displays a twofold reduction in hepatic gene expression and threefold reduction in hepatic protein expression of activin-treated cells compared with follistatin-treated cells. Moreover, subcutaneous transplantation of activin-treated cells in a syngeneic mouse generated a heterogeneous teratoma-like mass, suggesting that these were a more primitive population. In contrast, follistatin-treated cells resulted in an encapsulated epithelial-like mass, suggesting that these cells remained committed to the endoderm lineage. In conclusion, we demonstrate a novel technique to induce the direct differentiation of endoderm from mES cells without cell sorting. In addition, our work suggests a new role for activin in induction of the precursors to endoderm and a new endoderm-enrichment technique using follistatin.

Disclosure of potential conflicts of interest is found at the end of this article.
Pluripotential Reprogramming of the Somatic Genome in Hybrid Cells Occurs with the First Cell Cycle
Authors: Han Dong Wook , Do Jeong Tae , Gentile Luca , Stehling Martin , Lee Hoon Taek , Schöler Hans R.
Published: December 2007

The fusion of pluripotent embryonic cells with somatic cells results in reprogramming of the somatic cell genome. Oct4-green fluorescent protein (GFP) transgenes that do not contain the proximal enhancer (PE) region are widely used to visualize reprogramming of the somatic to the pluripotent cell state. The temporal onset of Oct4-GFP activation has been found to occur 40–48 hours postfusion. We asked whether activation of the transgene actually reflects activation of the endogenous Oct4 gene. In the current study, we show that activation of an Oct4-GFP transgene that contains the PE region occurs within 22 hours of fusion. In addition, demethylation of the Oct4-GFP transgene and that of the endogenous Oct4 and Nanog genes was found to occur within 24 hours of fusion. As this timing corresponds with the timing of cell cycle completion in embryonic stem cells and fusion hybrids (∼22 hours), we postulate that pluripotential reprogramming of the somatic cell genome begins during the first cell cycle after the fusion of a somatic cell with a pluripotent cell and has been completed by day 2 postfusion.

Disclosure of potential conflicts of interest is found at the end of this article.
Derivation, Characterization, and In Vitro Differentiation of Canine Embryonic Stem Cells
Authors: Hayes Brian , Fagerlie Sara R. , Ramakrishnan Aravind , Baran Szczepan , Harkey Michael , Graf Lynn , Bar Merav , Bendoraite Ausra , Tewari Muneesh , Torok-Storb Beverly
Published: December 2007

Canine embryonic stem (cES) cell lines were generated to establish a large-animal preclinical model for testing the safety and efficacy of embryonic stem (ES) cell-derived tissue replacement therapy. Putative cES cell lines were initiated from canine blastocysts harvested from natural matings. Times of harvest were estimated as 12–16 days after the presumed surge in circulating levels of luteinizing hormone. Four lines established from blastocysts harvested at days 13–14 postsurge satisfied most of the criteria for embryonic stem cells, whereas lines established after day 14 did not. One line, Fred Hutchinson dog (FHDO)-7, has been maintained through 34 passages and is presented here. FHDO-7 cells are alkaline phosphatase-positive and express both message and protein for the Oct4 transcription factor. They also express message for Nanog and telomerase but do not express message for Cdx2, which is associated with trophectoderm. Furthermore, they express a cluster of pluripotency-associated microRNAs (miRs) (miR-302b, miR-302c, and miR-367) characteristic of human and mouse ES cells. The FHDO-7 cells grow on feeder layers of modified mouse embryonic fibroblasts as flat colonies that resemble ES cells from mink, a close phylogenetic relative of dog. When cultured in nonadherent plates without feeders, the cells form embryoid bodies (EBs). Under various culture conditions, the EBs give rise to ectoderm-derived neuronal cells expressing γ-enolase and β3-tubulin; mesoderm-derived cells producing collagen IIA1, cartilage, and bone; and endoderm-derived cells expressing α-fetoprotein or Clara cell-specific protein.

Disclosure of potential conflicts of interest is found at the end of this article.
Treatment Efficiency and Stoichiometry of a High‐Strength Graywater
Authors: Morse Audra , Khatri Sukrut , Jackson W. Andrew
Published: December 2007

The transit mission wastewater may represent a future graywater, in which toilet waste is separated from other household waste streams, and dilution water is minimal. A loading rate study indicated that denitrification is stoichiometrically limited, and nitrification was kinetically limited. Denitrification stoichiometry was developed by deriving hypothetical molecular formulas of organic carbon inputs to be represented by the relative proportions of carbon, hydrogen, oxygen, and nitrogen. The derived stoichiometry was validated against experimental data by adjusting the values of f e and f s and multiplying the total dissolved organic carbon loss across the system by the overall R equation and then comparing the total nitrogen removed in the reaction to experimentally observed total nitrogen removal. The nitrification stoichiometry was similarly validated by multiplying the R equation by the ammonium‐nitrogen removed and then comparing the NOx‐N formed in the equation to actual NOx‐N production values. The f s values for the denitrifying and nitrifying bacteria were 0.33 and 0.15, respectively.
Adsorption and Precipitation of Tetracycline with Struvite
Authors: Başakçılardan‐Kabakcı Sibel , Thompson Andrew , Cartmell Elise , Le Corre Kristell
Published: December 2007

The interaction of tetracycline with struvite during adsorption and precipitation processes was investigated. Tetracycline removal by adsorption was affected by solution pH, contact time, and struvite concentration. The lowest tetracycline removal (8.4%) was observed at pH 7.7, the dissociation constant (pKa2) of tetracycline. Because of the electrostatic repulsion, the amount of tetracycline adsorbed on the surface was low. The small amount of adsorption was the result of surface complexation between tetracycline ions and metal ions. Calcium (Ca2+) ions in the adsorbent enhanced the binding of tetracycline. Freundlich (K F: 0.04, n: 1.49) and Redlich‐Peterson (K R: 0.08, αR: 0.98, βR: 0.49) models best defined the equilibrium data. In the case of struvite precipitation, approximately 22% of tetracycline was removed as a result of binding to struvite alongside struvite formation.
Implications of Urine‐to‐Feces Ratio in the Thermophilic Anaerobic Digestion of Swine Waste
Authors: Creamer K. S. , Williams C. M. , Chen Y. , Cheng J. J.
Published: December 2007

Thermophilic anaerobic digestion of swine manure represents a potential waste treatment technology to address environmental concerns, such as odor emissions and removal of pathogenic microorganisms. However, there are concerns relative to the stability of this process when swine manure is the sole substrate. In this study, the potential of biogas production from swine manure as the sole substrate under thermophilic (50°C) conditions was investigated in the laboratory, to determine whether separation of urine and feces as part of the waste collection process would benefit anaerobic digestion. Effluent from a continuously stirred tank reactor was used as the inoculum for batch tests, in which the substrate contained three different concentrations of urine (urine‐free, as‐excreted urine‐to‐feces ratio and double the as‐excreted urine‐to‐feces ratio). Inocula were acclimated to these same urine‐to‐feces ratios to determine methane production. Results show that both urine‐free and as‐excreted substrates were not inhibitory to anaerobic inocula. Anaerobic microorganisms can be readily acclimated to substrate with double the as‐excreted urine concentration, which contained nitrogen concentrations up to 7.20 g/L. Cumulative methane production reached similar levels in the batch tests, regardless of the substrate urine concentration.
Irreversible Fouling During Multicycle Microfiltration of Wastewater Effluent
Authors: Shan Huifeng , Neufeld Ronald D.
Published: December 2007

This study focused on irreversible fouling during microfiltration of primary and secondary effluents from municipal wastewater treatment plants. Flow resistances were calculated from the sum of clean membrane resistances, resultant cake layer resistances, and consequent irreversible fouling resistances. Results from a dead‐end cell experimental system showed that the accumulated cake resistance was dominating for microfiltration of primary/secondary effluents. Suspended solids in the primary and secondary effluents had a similar compressibility index, n, with a value of approximately 0.5, indicating that they were moderately compressible particles. The value of irreversible resistance is dependent on the intensity of membrane cleaning; however, for a given membrane cleaning strategy, this value steadily increased and reached a maximum after approximately 6 cycles of filtration and cleaning. This study provided an explanation for the significant drop of throughput flux in the early application of membrane processes, and a plateau flux approached correspondingly.
Reduced Immunogenicity of First-Trimester Human Fetal Pancreas
Authors: Brands Kerstin , Colvin Emily , Williams Lindy J. , Wang Rennian , Lock Richard B. , Tuch Bernard E.
Published: December 2007

OBJECTIVE—The use of human fetal pancreatic tissue may provide a potential source of transplantable β-cells as a therapy for type 1 diabetes. Human fetal pancreas has a remarkable capacity to grow and differentiate in vivo and has been shown to reverse diabetes in rodents. However, it is known that human fetal pancreas obtained from the second trimester of gestation is immunogenic and is rejected after transplantation. Tissue obtained from earlier stages might prove to be immune privileged, as has been shown for other tissues.

RESEARCH DESIGN AND METHODS—In this study, we determined the immunogenicity of human fetal pancreatic tissue obtained from the first trimester of gestation in a humanized mouse model. A microarray study of immunoregulatory gene expression in first- and second-trimester human fetal pancreas was also undertaken.

RESULTS—The analysis of transplanted human fetal pancreata revealed a significantly decreased immunogenicity of the first-trimester tissue. The first-trimester grafts showed only limited cellular infiltration and contained numerous insulin-positive cells, whereas second-trimester tissue was completely infiltrated and rejected. Furthermore an analysis of immunoregulatory genes expressed in first- and second-trimester human fetal pancreas by microarray demonstrated the upregulation of several key immunoregulatory genes in the second-trimester tissue. This might account for the reduced immunogenicity of the younger tissue.

CONCLUSIONS—Our results provide the first indication that the use of first-trimester human fetal pancreas for transplantation might increase the survival of the grafts and might decrease the requirement for immunosuppressive drugs.
Phase transitions of K2TaF7 within 680–800°C
Authors: Kosa Ladislav , Macková Iveta , Proks Ivo , Pritula Ondrej , Smrčok Ľubomír , Boča Miroslav , Rundlőf Håkan
Published: December 2007

Three thermal effects on heating/cooling of K2TaF7 in the temperature interval of 680–800°C were investigated by the DSC method. The values determined for the enthalpy change of the individual processes are: ΔtransIIHm(K2TaF7; 703°C) = 1.7(2) kJ mol−1, ΔtransIHm(K2TaF7; 746°C) = 19(1) kJ mol−1 and ΔtransIIIHm(K2TaF7; 771°C) = 13(1) kJ mol−1. The first thermal effect was attributed to a solid-solid phase transition; the second to the incongruent melting of K2TaF7 and the third to mixing of two liquids. These findings are supported by in situ neutron powder diffraction experiments performed in the temperature interval of 654–794°C.
Preparation and shape control of β-Ni(OH)2 nano-particle
Authors: Gao Yuan , Liu Huitao , Ma Mianjun
Published: December 2007

A simple and convenient method for the preparation of needle-shape nanoparticles of β-Ni(OH)2 has been developed. Results show that a needle-shaped β-Ni(OH)2 can be easily obtained in the presence of ethylenediamine and sodium dodecylbenzene sulfonate within a size from 100 to 200 nm. The shape and structure of the product were characterized by XRD, TEM and FT-IR. It is noteworthy that the formation of needle-shape β-Ni(OH)2 benefits from the addition of sodium dodecylbenzene sulfonate. The optimum preparation conditions and the possible mechanism are also discussed.
Palladium-catalyzed amination of quinaldine-5-triflate
Authors: Fekete Melinda , Töröncsi Mercedesz , Novak Lajos
Published: December 2007

Palladium-catalyzed amination reactions of quinoline triflate and the effect of a Pd catalyst, its ligands, solvents, bases, and temperature were studied. This method facilitated an easier pathway for the preparation of aminoquinoline derivatives as potential precursors of new serotoninerg agents.
Navigated versus conventional drilling of the knee in a model of obesity
Authors: Beckmann Johannes , Tingart Markus , Goetz Juergen , Anders Sven , Grifka Joachim , Kock Franz
Published: December 2007

Core decompression by exact drilling into ischemic lesions of the femoral condyle stays a challenging procedure, particularly in obese patients. The precision of fluoroscopically-based drilling compared to conventional drilling was evaluated in an in-vitro model for obesity. 40 sawbones were prepared mimicking osteonecrosis in obese patients. 20 sawbones were drilled by guidance of an intraoperative navigation system VectorVision® (BrainLAB, Munich, Germany); the other 20 sawbones were conventionally drilled by fluoroscopic control only. Regarding the distance to the desired mid-point of the lesion, a statistically significant difference with 0.55 mm in the navigated group and 1.19 mm in the control group could be stated (p<0.001). Significant differences were further found for the number of drilling corrections (p<0.001) and radiation time needed (p<0.001). Even in difficult circumstances as in obese patients, the drilling guided by the VectorVision®-navigation system shows high precision with simultaneous enormous reduction of radiation time.
Photocatalytic reduction of CO2 over TiO2 based catalysts
Authors: Kočí Kamila , Obalová Lucie , Lacný Zdeněk
Published: December 2007

At present, carbon dioxide is considered the largest contributor among greenhouse gases. This review covers the current state of problem of carbon dioxide emissions from industrial and combustion processes, the principle of photocatalysis, existing literature related to photocatalytic CO2 reduction over TiO2 based catalysts and the effects of important parameters on the process performance including light wavelength and intensity, type of reductant, metal-modified surface, temperature and pressure.
Modeling of enzymatic reaction in an airlift reactor using an axial dispersion model
Authors: Sikula Ivan , Markoš Jozef
Published: December 2007

This work was focused on modeling of biochemical processes in a 40-L internal-loop airlift reactor. Due to different mixing in the specific zones of the reactor four main sections, bottom, riser, separator and downcomer, were recognized. Each zone was modeled by an adequate mixing model: bottom and separator sections by the model of ideally-stirred reactor; riser and downcomer sections by the model of plug-flow reactor with axial dispersion. In the model, the effects of mass transfer, hydrodynamics, and reaction kinetics were taken into account. The model of the reactor was experimentally verified by the aerobic enzymatic oxidation of glucose to gluconic acid. Simulations are in good agreement with experimental data.
HAZOP study of a fixed bed reactor for MTBE synthesis using a dynamic approach
Authors: Labovský Juraj , Švandová Zuzana , Markoš Jozef , Jelemenský L’udovít
Published: December 2007

A methodology for hazard investigation based on the integration of a mathematical model approach into hazard and operability analysis is presented. This approach is based on mathematical modelling of a process unit where both steady-state analysis, including analysis of the steady states multiplicity and stability, and dynamic simulation are used. The dynamic simulation serves for the investigation of consequences of failures of the main controlled parameters, i.e. inlet temperature, feed temperature and feed composition. This simulation is also very useful for the determination of the influence of failure duration on the reactor behaviour. On the other hand, the steady state simulation can predict the reactor behaviour in a wide range of failure magnitude and determine the parametric zones, where shifting from one steady state to another one may occur. A fixed bed reactor for methyl tertiary-butyl ether synthesis was chosen to identify potential hazard and operational problems of a real process.
Influence of the reactive distillation column configuration on its performance: A computational study
Authors: Švandová Zuzana , Markoš Jozef , Jelemenský L’udovít
Published: December 2007

Comparison of the performance of a reactive distillation column with three different hardware configurations is presented. As a reaction system the methyl tertiary-butyl ether (MTBE) synthesis has been chosen. The sieve tray columns with catalyst (encased inside wire gauze envelopes) placed along the liquid flow path differ in the number of reactive trays. The column simulations have been performed using the nonequilibrium model. The steady state behaviour of the three different hardware configurations was studied regarding the three input parameters; feed flow rate of methanol, feed flow rate of butenes, and reflux ratio. It has been shown that by varying the location of the methanol feed stage, the columns exhibit significantly different solution diagrams using the butenes feed flow rate as a continuation parameter. Using dynamic simulations, different perturbations of the manipulated variables were found to cause transitions between multiple steady states and these were also investigated. The major objective of this paper is to demonstrate the importance of the hardware choice in the performance of a reactive distillation column e.g. during the start-up or if occasional variations of the operating parameters occur.
Reactive distillation — experimental data for propyl propionate synthesis
Authors: Kotora Marcel , Buchaly Carsten , Kreis Peter , Górak Andrzej , Markoš Jozef
Published: December 2007

A set of experimental data for heterogeneously catalysed esterification of propan-1-ol and propionic acid to propyl propionate in a pilot scale reactive distillation column is presented. The catalytic section of the column was equipped with the structured packing Katapak SP-11. Both, rectifying and stripping, sections consisted of the non-reactive structured Sulzer BX packing. As catalyst, the strongly acidic ion-exchange resin Amberlyst 46 was used. The experimental results show concentration as well as temperature profiles along the column height and therefore exhibit reliable data for model validation purposes.
Mixing time of a non-Newtonian liquid in an unbaffled agitated vessel with an eccentric propeller
Authors: Szoplik Jolanta , Karcz Joanna
Published: December 2007

Experimental study of mixing time of non-Newtonian shear-thinning fluids within the transitional regime (3 × 102 < Re < 3 × 103) of liquid flow is presented. The purpose of this study was to analyze the effect of eccentricity and pumping mode of the impeller as well as of position of the tracer dosage point into the agitated liquid on mixing time. The measurements were conducted in an unbaffled agitated vessel with inner diameter D = 0.7 m equipped with an up-or down-pumping propeller located centrically (e/R = 0) or eccentrically (e/R ≠ 0) in the vessel. Experiments were carried out by means of computer-aided unsteady-state thermal method for three positions of the tracer dosage point. The experimental data show that eccentric position of the propeller in an unbaffled vessel causes a decrease of the mixing time compared to that obtained in a vessel with a centrically located propeller. Mixing time depends also on the pumping mode of the propeller as well as on the position of the tracer dosage point.
Heat transfer coefficient and pressure drop during refrigerant R-134a condensation in a plate heat exchanger
Authors: Djordjević Emila , Kabelac Stephan , Šerbanović Slobodan
Published: December 2007

The condensation heat transfer coefficient and the two-phase pressure drop of refrigerant R-134a in a vertical plate heat exchanger were investigated experimentally. The area of the plate was divided into several segments along the vertical axis. For each of the segments, local values of the heat transfer coefficient and frictional pressure drop were calculated and presented as a function of the mean vapor quality in the segment. Owing to the thermocouples installed along the plate surface, it was possible to determine the temperature distribution and vapor quality profile inside the plate. The influences of the mass flux and the heat flux on the heat transfer coefficient and the pressure drop were also taken into account and a comparison with previously published experimental data and literature correlations was carried out.
Distribution of local heat transfer coefficient values in the wall region of an agitated vessel
Authors: Cudak Magdalena , Karcz Joanna
Published: December 2007

Experimentally found local heat transfer coefficients are analyzed as a function of the measuring point on the heat transfer surface area of the agitated vessel wall and of the impeller eccentricity. Eccentric Rushton turbine and A 315 impeller are considered. Local heat transfer coefficients were measured by means of the computer-aided electrochemical method. The measurements were performed in an agitated vessel with inner diameter 0.3 m, filled with liquid up to the height equal to the vessel diameter. The experiments were carried out within the turbulent regime of the Newtonian liquid flow in the agitated vessel. The results were compared with the data obtained for the agitated vessel equipped with an eccentrically located axial flow propeller or an HE 3 impeller. Experimental studies show that the distributions of the heat transfer coefficient values depend on the impeller eccentricity, impeller type and the direction of the liquid circulation in the agitated vessel.
Validation of the Tessier scheme for speciation of metals in soil using the Bland and Altman test
Authors: Frentiu Tiberiu , Ponta Michaela , Levei Erika , Gheorghiu Emilia , Kasler Iosif , Cordos Emil
Published: December 2007

The Tessier extraction method was used for speciation of Cu, Pb, Zn, As, Fe and Mn in a large concentration range in contaminated soil with various mineralogical compositions. The results were compared by X-ray fluorescence spectrometry (XRF) as a reference method using the Bland and Altman test. A sum of five fractions (exchangeable, bound to carbonates, Fe-Mn oxides, organic matter and residual forms) was compared with the total content determined on solid matrix by the reference method. A good agreement between the methods in the whole concentration range was found for Cu, Zn, As, and Fe. For Mn and Pb, XRF was found suitable to verify the sequential extraction only for concentrations above 250 mg kg−1. This was a consequence of a poorer reproducibility of Pb extraction using the Tessier scheme due to a great difference in the mineralogical composition and the diversity of the Pb species identified in soil. The poorer result of Mn was attributed to the spectral interference of Fe in XRF.
Perspective methods of human identification: Ear biometrics
Authors: Choraś M.
Published: December 2007

Geometrical methods of feature extraction from ear images in order to perform human identification are presented. Geometrical approach is motivated by the actual procedures used by police and forensic experts (so-called ear otoscopy). In their work, geometrical features of ears such as size, height, width, and shapes of earlobe are useful and valid proofs of identity. The contribution of the article is development of the new and original methods of geometrical feature extraction from 2D ear images. Four novel algorithms of ear feature extraction from contour images are described in detail. Moreover, identification results obtained for each of the methods, based on the distance of feature vectors in the feature space, are presented.
Ruthenium Anticancer Compounds: Challenges and Expectations
Authors: Bratsos Ioannis , Jedner Stephanie , Gianferrara Teresa , Alessio Enzo
Published: December 2007

Two ruthenium compounds, namely [ImH]trans-[RuCl4(Im)(dmso-S)] (NAMI-A, Im = imidazole) and [IndH] trans-[RuCl4(Ind)2] (KP1019, Ind = indazole) have already completed phase I clinical trials as anticancer agents. They both have properties
different from platinum anticancer drugs: for example, NAMI-A is selectively active against metastases of solid tumors. They show that in the field of anticancer metal drugs a new approach, based on targeted therapies, is possible. After a concise history of ruthenium anticancer compounds,
this contribution will focus on ruthenium-dmso complexes and, in particular, on NAMI-A. Particular emphasis is given on the challenges that are inherent to this field: how to develop new anticancer ruthenium compounds and how to select new active compounds that manifest their anticancer activity
through non-conventional mechanisms.
Platinum Pyrimidine Blues: Still a Challenge to Bioinorganic Chemists and a Treasure for Coordination Chemists
Authors: Lippert Bernhard
Published: December 2007

A class of intensely colored platinum complexes, derived from the hydrolysis product of the antitumor agent cisplatin, cis-[Pt(NH3)2(H2O)2]2+, and pyrimidine nucleobases (pym) and related cyclic or open amides, and generally
termed 'Platinum Blues', is discussed. First reported over 30 years ago, major questions concerning their nature have been solved since then, for example their mixed valency and paramagnetism. Their modes of action as antitumor agents and as nucleic acid stains remain elusive, however. It
has generally been assumed that the 'Blues' adopt linear chain structures, thus permitting short Pt•••Pt contacts, but more recent findings demonstrate that these ligands also allow cyclic structures to be formed (metallacalix[n]arenes). They provide a wealth of interesting
properties with regard to host–guest chemistry and non-covalent DNA binding. These developments are reviewed.
Medicinal Applications of Metal–Peptide Bioconjugates
Authors: Metzler-Nolte Nils
Published: December 2007

Organometal–peptide bioconjugates have a variety of applications in biomedical studies, such as antiproliferative and anti-bacterial activity, as well as to aid the elucidation of the mode of action of the conjugated metal complexes. Our group has developed the solid-phase synthesis
of organometal–peptides by different synthesis schemes, their characterization and use in biomedical studies. Selected examples are presented in this review.
Speech by any other name: the role of communication aids in interaction
Authors: Smith Martine M.
Published: December 2007

ABSTRACTS

The functional communication systems of four physically disabled children with severe speech impairment were evaluated in terms of: (1) perceived dominant modes of communication; (2) observed frequency of communication mode occurrence; and (3) role of communication device in total communication system. All four subjects used a range of communication modes to reflect personal and listener preferences, and in response to differing conversational requirements. ‘Standard’ communication modes were mentioned more frequently by teachers and parents, and were observed more frequently in interactions. Augmentative and alternative communication devices played a limited but important role within total communication systems. A hierarchy of influences affecting the choice of communication mode is suggested.

Les systèmes fonctionnels de communication de quatre enfants infirmes physiques et souffrant de déficiences sévères de la parole, ont été evalués en fonction des critères suivants: (1) les modes de communication perçus comme dominants, (2) les fréquences observés des manifestations des modes de communication, et (3) le rǒle de l'outil communicatif au sein du système global de communication. Les quatre sujets ont tous utilisé un ensemble de modes de communication qui reflétaient des préférences personnelles et celles des auditeurs, et en fonction des différents besoins de la conversation. Ce sont les modes de communication ‘standard’ qui ont été mentionnés le plus fréquemment par les enseignants et les parents, et qui ont été observés le plus souvent dans les interactions. Les moyens de communication alternatifs et augmentatifs ont joué un rǒle limité, mais malgré tout important, dans le cadre total des systèmes de communication. Il est suggéré qu'il existe une hiérarchie d'influences qui détermine le choix des modes de communication.

Die funktionalen Kommunikationssysteme vierer körperlich behinderter Kinder mit starker Sprachbehinderung wurden hinsichtlich folgender Dimensionen evaluiert: (1) Wahrgenommener dominanter Kommunikationsmodus; (2) beobachtete Häufigkeit der Kommunikationsmodi; (3) Rolle einer Kommunikationshilfe im gesamten Kommunikationssystem Alle vier Personen verwendeten eine Reihe unterschiedlicher Kommunikationsmodi, die die persönlichen Präferenzen und die der Hörer widerspiegelten und die den verschiedenen Gesprächsbedürfnissen angepaßt waren. ‘Standardmodi’ der Kommunikation wurden häufiger von Lehrern und Eltern erwähnt und wurden auch in Interaktionen häufiger beobachtet. Alternative, zusätzliche Kommunikationshilfen spielten eine begrenzte aber wichtige Rolle innerhalb des gesamten Kommunikationssystems. Eine Hierarchie von Einflußgrößen wird konstatiert, die sich auf die Wahl des Kommunikationsmodus auswirkt.
Conversation as therapy for older adults in residential care: the case for intervention
Authors: Erber Norman P.
Published: December 2007

ABSTRACTS

Social isolation resulting from sensory loss tends to reduce life satisfaction in older adults. Residence in a long‐term care facility such as a nursing home does little to alleviate their communication needs. Potenial communication partners are available (e.g. other residents, family and friends, nursing staff, volunteers, health‐care workers), but many need instruction, counselling and feedback to become therapeutically effective. The speech pathologist's experience as both communication therapist and social facilitator can enhance consultation and staff training in this area

Chez les personnes ǎgées le déclin de la vue et de l'ouïe crée un isolement social qui réduit le sentiment de bien‐ětre. Résider dans un univers de soins à long terme comme une maison de retraite n'apporte guère a la satisfaction des besoins de communication. Il existe certes des interlocuteurs (par example les autres résidents, la famille et les amis, le personnel soignant, les bénévoles, les assistants sociaux) mais beaucoup auraient besoin de formation, de conseils et d'information en retour pour acquérir une efficacité thérapeutique. L'expérience du spécialiste de la pathologie de la parole, en tant que thérapeute de la communication et facilitateur social, peut avoir un effet positif sur la consultation et sur l'entrainement du personnel dans ce domaine.

Soziale Isolation als Folge sensorischer Verluste trägt zur Reduktion der Lebenszufriedenheit älterer Menschen bei. Das Wohnen in einer Fürsorgeanstalt, z.B. in einem Pflegeheim, hilft wenig, ihre Kommunikationsbedürfnisse zu erfüllen. Potentielle Kommunikationspartner sind vorhanden (z.B. andere Bewohner, Familienmitglieder und Freunde, Pflegepersonal, Freiwillige Helfer, Sozialarbeiter), aber viele brauchen Hinweise, Beratung und Rückkopplung, um therapeutisch wirksam werden zu können. Die Erfahrung des Sprachtherapeuten als Kommunikationstherapeut und als Förderer sozialer Interaktion kann zur Besserung der Konsultation und der Ausbildung in diesem Bereich beitragen.
Analyse d'une situation de détection et de localisation
Authors: Richard Jean-François , Rouanet H.
Published: December 2007

The influence of the frequency of stimulus and the nature of the preceding stimulus have been analyzed in a detection-localisation situation consisting in detecting the position of the lacuna of a Landolt ring presented in short time vision. In the four cases considered, ranging from an uniform distribution of stimulus to an unimodal and little dispersed distribution, effects of positive recency were found.

Two mathematical adaptation models have been devised in an attempt to give an account of the overall results. Both imply the existence of a preparatory state varying from trial to trial and assume an all-or-nothing detection mechanism (an assumption compatible with the observations, at least as a first approximation). They essentially differ in that one of them assumes that the detection probability is independant from the preparatory state whereas the other assumes a higher detection probability when the stimulus is very close to the preparatory state than when it is far away.

Both models include the same number of parameters. Confronted to observations, the second model is far more satisfactory : it predicts — with a generally great accuracy — the amplitude of the recency and frequency effects wherever they are to be found. time vision. In the four cases considered, ranging from an uniform distribution of stimulus to an unimodal and little dispersed distribution, effects of positive recency were found.

Two mathematical adaptation models have been devised in an attempt to give an account of the overall results. Both imply the existence of a preparatory state varying from trial to trial and assume an all-or-nothing detection mechanism (an assumption compatible with the observations, at least as a first approximation). They essentially differ in that one of them assumes that the detection probability is independant from the preparatory state whereas the other assumes a higher detection probability when the stimulus is very close to the preparatory state than when it is far away.

Both models include the same number of parameters. Confronted to observations, the second model is far more satisfactory : it predicts — with a generally great accuracy — the amplitude of the recency and frequency effects wherever they are to be found.
Déficit mnésique d'origine organique et niveaux d'organisation des tâches à mémoriser
Authors: de Schonen S
Published: December 2007

Two groups of patients, with frontal, temporal, parietal and 3rd vent. lesions, have been investigated. The experience was designed to test the importance of increasing levels of organization of 4 tasks in short-term and long term memory. Two modalities of learning have been chosen : one group of subjects was presented with each task only once for a fixed duration while the other group was allowed to carry on the learning until criterion was reached (one fautless recall).

Recall tests were carried out 24 hours later for both groups.

Results show that for the patients we have studied, forgetting is inversely related to the organization level of tasks, irrespective to learning modalities. duration while the other group was allowed to carry on the learning until criterion was reached (one fautless recall).

Recall tests were carried out 24 hours later for both groups.

Results show that for the patients we have studied, forgetting is inversely related to the organization level of tasks, irrespective to learning modalities.
Vers une neuropsychologie humaine des conduites émotionnelles?
Authors: Seron Xavier , Van der Linden Martial
Published: December 2007

Dans cette revue, les auteurs présentent brièvement les principaux troubles affectifs résultant d'une atteinte cérébrale et les modes traditionnels d'approche qui ont été développés pour étudier ces problèmes (syndrome psycho-organique, techniques projectives, neuropsychologie clinique). Ils analysent ensuite les travaux expérimentaux récents portant sur la spécialisation interhémisphérique des conduites affectives. Dans la discussion, l'accent est mis sur le fait qu'une compréhension plus précise du rôle de l'hémisphère droit exige la clarification simultanée de plusieurs autres questions relatives au rôle des structures sous-corticales dans la réactivité émotionnelle, à celui de l'hémisphère gauche et du système fronto-limbique dans le contrôle des émotions, et à l'éventuelle existence de localisations intrahémisphériques droites. On souligne l'importance de la distinction entre troubles primaires et troubles secondaires, ainsi que le manque d'études sur la personnalité antérieure des sujets et leur environnement socioculturel au moment de l'atteinte cérébrale.
Parameter Passing
Authors: Weiss Mark Allen
Published: December 2007

Modern programming languages use various techniques to pass parameters to a function (or method). We discuss the techniques used in some of the more popular programming languages in current use, namely C, C++, Ada, Java, and C#, and mention some techniques found in other languages.