bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic flow and electroosmotic flow in zirconia‐packed capillaries
Authors: Crosnier de Bellaistre Myriam , Randon Jérôme , Rocca Jean‐Louis
Published: February 2006

Fused‐silica capillaries were packed with Zirchrom®‐PBD stationary phase for application in CEC, nanoLC and pseudoelectrochromatography (PEC). Acido‐basic properties of zirconia can be used to control the EOF even if the zirconia particles were coated by polybutadiene. As for native zirconia, the EOF is pH‐dependent and the pI is close to pH 5. The mixed‐mode pressure–voltage technique induced a modulation of the mobile‐phase velocity as well as an electrophoretic migration of the solutes in order to improve the resolution of the separation. A significant increase of the flow appeared when both hydrodynamic and EOFs were in the same direction. But an important reduction of the electroosmotic velocity was observed when the hydrodynamic flow and EOF were opposed in Zirchrom‐PBD columns. This behaviour has been observed at high or low pH on several columns. Separations of neutral and charged compounds have been performed with these columns in PEC mode.
Selection of two reliable parameters to evaluate the impact of the mobile‐phase composition on capillary electrochromatography performance with monolithic and particle‐packed capillary columns
Authors: Progent Frédéric , Augustin Violaine , Tran N. Thuy , Descroix Stéphanie , Taverna Myriam
Published: February 2006

Different models have been described in the literature to evaluate the total porosity of CEC columns: gravimetric, flow as well as conductivity‐based methods. In this study, these models have been compared for two kinds of CEC columns: two mixed‐mode silica particle stationary phases and different monolithic columns (acrylate or polystyrene divinylbenzene‐based). The total porosities measured from the conductivity‐based methods were lower than the total column porosities obtained by gravimetric or flow methods for all the investigated columns while the wide distribution of observed values shows that conductivity‐based methods discriminate columns more efficiently with very different properties. We propose a conductivity‐based method taking into account the actual length proposed by Horvath, to evaluate what we call an ”actual electrokinetic” porosity (AEP). This parameter, based on electrokinetic theory only, affords the most consistent evaluation of porosity under experimental CEC conditions for the packed‐ and acrylate‐based monolithic columns. To illustrate the potential of AEP and actual EOF for the estimation of the performances of a CEC system (stationary and mobile phases) we studied the influence of the mobile‐phase composition on these parameters for CEC separations with an ammonium embedded packed stationary phase. The AEP and the actual electroosmotic mobility should allow a better understanding of the perfusive EOF and stationary‐phase wettability. For neutral compounds (substituted phenols), AEP evaluation allowed us to predict the mobile‐phase conditions able to enhance the efficiency while both AEP and actual EOF had to be considered in the case of peptide analysis.
Enantiomeric screening of racemic citalopram and metabolites in human urine by entangled polymer solution capillary electrophoresis: An innovatory robustness/ruggedness study
Authors: Berzas‐Nevado Juan José , Villaseñor‐LLerena María Jesús , Guiberteau‐Cabanillas Carmen , Rodríguez‐Robledo Virginia
Published: February 2006

Several CE methods have been developed to achieve the chiral separation of citalopram (CIT) and its metabolites demethylcitalopram (DCIT), didemethylcitalopram (DDCIT), and citalopram N‐oxide (CIT‐NO). All of these compounds were present as racemic mixtures. The best method, which led to the first ever chiral screening of CIT, DCIT, DDCIT, and CIT‐NO, involved the use of carboxymethyl‐γ‐CD (CM‐γ‐CD) and the entangled polymer hydroxypropylmethylcellulose (HPMC) as chiral and selectivity additives, respectively, in the buffer system. In an effort to improve the selectivity and sensitivity of the method, the chemical and instrumental parameters were optimized. The best conditions were short‐end anodic hydrodynamic injection (6 s, 0.7 psi); as BGE pH 5, 20 mM phosphate buffer, 0.2% w/v CM‐γ‐CD, 0.05% w/v HPMC; voltage of 28 kV with a ramp applied (0.4 s); cartridge temperature of 20°C; detection at 205 nm. In addition, a simple and rapid achiral CE method for the determination of citalopram propionic acid (CIT‐PA, the only anionic metabolite of CIT) is also reported for the first time. Prior to the electrophoretic procedure it was necessary to apply an extraction and preconcentration step to obtain analytes from the human urine samples. This was achieved using an optimized SPE process. Moreover, an innovatory experimental and statistical design approach, which involves the simultaneous evaluation of the global robustness and ruggedness effects, was applied. Both of the proposed methods proved to be very useful in the chiral pharmacokinetic screening of CIT and related metabolites in clinical human urine samples.
Micellar electrokinetic chromatography and capillary electrochromatography of nitroaromatic explosives in seawater
Authors: Giordano Braden C. , Copper Christine L. , Collins Greg E.
Published: February 2006

The ability to separate nitroaromatic and nitramine explosives in seawater sample matrices is demonstrated using both MEKC and CEC. While several capillary‐based separations exist for explosives, none address direct sampling from seawater, a sample matrix of particular interest in the detection of undersea mines. Direct comparisons are made between MEKC and CEC in terms of sensitivity and separation efficiency for the analysis of 14 explosives and explosive degradation products in seawater and diluted seawater. The use of high‐salt stacking with MEKC results, on average, in a three‐fold increase in the number of theoretical plates, and nearly double resolution for samples prepared in 25% seawater. By taking advantage of long injection times in conjunction with stacking, detection limits down to sub mg/L levels are attainable; however, resolution is sacrificed. CEC of explosive mixtures using sol‐gels prepared from methyltrimethoxysilane does not perform as well as MEKC in terms of resolving power, but does permit extended injection times for concentrating analyte onto the head of the separation column with little or no subsequent loss in resolution. Electrokinetic injections of 8 min at high voltage allow for detection limits of explosives below 100 µg/L.
Rapid separation and determination of carbamate insecticides using isocratic elution pressurized capillary electrochromatography
Authors: Wu Xiaoping , Wang Ling , Xie Zenghong , Lu Jieshan , Yan Chao , Yang Pengyuan , Chen Guonan
Published: February 2006

An isocratic elution pressurized CEC (pCEC) system was used to separate and determine ten carbamate insecticides. It was found that introduction of the electrical field, supplementary pressure, and SDS in the proposed method greatly improved the speed, column efficiency, selectivity, and repeatability for separation and determination of carbamates. On a capillary column of 75 µm ID packed with 3 µm octadecyl silica, baseline separation and detection of ten analytes was performed by using a mobile phase consisting of 30% v/v ACN and 70% v/v of 5 mmol/L ammonium acetate (pH 6.5) containing 1 mmol/L SDS and 0.01% triethylamine (TEA). Under the optimum conditions ten carbamate insecticides could be completely separated within 20 min. For the real vegetable samples, an SPE procedure for the cleanup of matrices was carried out prior to pCEC analysis. The detection limits of 0.05–1.6 mg/kg for ten carbamates and mean recoveries of 51.3–109.2% for eight kinds of vegetable samples at different concentrations of carbamates with RSD less than 11.4% were obtained, respectively. The proposed method has been proved to be effective in the rapid analysis of carbamate residues in vegetables.
Capillary zone electrophoretic chiral discrimination using 6‐O‐(2‐hydroxy‐3‐trimethylammoniopropyl)‐β‐cyclodextrin as a chiral selector
Authors: Lin Xiuli , Zhao Minggang , Qi Xinyu , Zhu Chenfu , Hao Aiyou
Published: February 2006

A charged highly water‐soluble CD derivative, 6‐O‐(2‐hydroxy‐3‐trimethylammoniopropyl)‐β‐CD (herein noted as 6‐HPTMA‐β‐CD) was synthesized and successfully used as a chiral selector for enantiomeric separation of some acidic compounds by CZE in an uncoated capillary. Substitution with 2‐hydroxy‐3‐trimethylammoniopropyl groups at the primary hydroxyl group of the CD was aimed at influencing the magnitude and selectivity of analyte–CD interactions. The behavior of 6‐HPTMA‐β‐CD was compared with that of the commercially available quaternary ammonium‐β‐CD (QA‐β‐CD) under the same separating conditions. The experiments were carried out using a BGE consisting of 50 mM phosphate in the pH range of 4–6 by adding a relatively low concentration of chiral selector (less than 10 mM). The effects of the concentration of CD and the pH of the electrolyte on the resolution of these compounds were studied.
CEC and EKC 2006
Authors: El Rassi Ziad
Published: February 2006

No abstracts.
Using Rock‐Eval 6 pyrolysis for tracking fossil organic carbon in modern environments: implications for the roles of erosion and weathering
Authors: Copard Yoann , Di‐Giovanni Christian , Martaud Thomas , Albéric Patrick , Olivier Jean‐Emmanuel
Published: February 2006

This work relates to the debate on the fossil organic carbon (FOC) input in modern environments and its possible implication for the carbon cycle, and suggests the use of Rock‐Eval 6 pyrolysis as a relevant tool for tracking FOC in such environments. Considering that such a delivery is mainly due to supergene processes affecting the continental surface, we studied organic matter in different reservoirs such as bedrocks, alterites, soils and rivers in two experimental catchments at Draix (Alpes de Haute Provence, France). Samples were subjected to geochemical (Rock‐Eval 6 pyrolysis) investigations and artificial bacterial degradations. After comparing the geochemical fingerprint of samples, geochemical markers of FOC were defined and tracked in the different reservoirs. Our results confirm the contribution of FOC in modern soils and rivers and display the various influences of weathering and erosional processes on the fate of FOC during its exchange between these pools. In addition, the contrasting behaviour of these markers upon the supergene processes has also highlighted the refractory or labile characters of the fossil organic matter (FOM). Bedrock to river fluxes, controlled by gully erosion, are characterized by a qualitative and quantitative preservation of FOM. Bedrock to alterite fluxes, governed by chemical weathering, are characterized by FOC mineralization without qualitative changes in deeper alterites. Alterite to soils fluxes, controlled by (bio)chemical weathering, are characterized by strong FOC mineralization and qualitative changes of FOM. Thus weathering and erosional processes induce different FOM evolution and affect the fate of FOC towards the global carbon cycle. In this study, gully erosion would involve maintenance of an ancient sink for the global carbon cycle, while (bio)chemical processes provide a source of CO2. Finally, this study suggests that Rock‐Eval 6 pyrolysis can be considered as a relevant tool for tracking FOC in modern environments. Copyright © 2006 John Wiley & Sons, Ltd.
Tea, hormone‐related cancers and endogenous hormone levels
Authors: Wu Anna H. , Yu Mimi C.
Published: February 2006

Tea is one of the most popular beverages consumed around the world, second only to water. There has been substantial interest in the potential role of tea in cancer prevention, particularly in respiratory and gastrointestinal tract cancers. Recent epidemiological data have linked tea intake to reduced risk of hormone‐related cancers, including breast, ovarian and prostate cancers. Based on sparse data, there is suggestion that tea intake may influence circulating hormone levels, providing a plausible mechanism whereby tea intake may influence risk of hormone‐related cancers. The major objectives of this paper are to review the epidemiological evidence on tea and risk of breast, ovarian, and prostate cancers as well as the human and non‐human studies on tea and circulating hormone levels. We pay special attention to some of the limitations of the human studies and discuss future research needs.
Intracellular signaling network as a prime chemopreventive target of (–)‐epigallocatechin gallate
Authors: Na Hye‐Kyung , Surh Young‐Joon
Published: February 2006

Chemoprevention is an attempt to use either naturally occurring or synthetic substances or their mixtures to intervene in the progress of carcinogenesis. Recently, it has been shown that some edible phytochemicals alter gene expression, directly or indirectly, thereby regulating the carcinogenic processes. (–)‐Epigallocatechin gallate (EGCG), a principal antioxidant derived from green tea, is one of the most extensively investigated chemopreventive phytochemicals. EGCG has been known to block each stage of carcinogenesis by modulating signal transduction pathways involved in cell proliferation, transformation, inflammation, apoptosis, metastasis and invasion. This review addresses the molecular target‐based chemoprevention with EGCG by focusing on the common events mediated by transcription factors, such as NF‐kappa B, activator protein‐1 and nuclear factor erythroid 2 p45‐related factor, and upstream kinases involved in the cellular signaling network.
Cover Picture: Plasma Process. Polym. 2/2006
Authors: Supiot Philippe , Vivien Céline , Granier Agnès , Bousquet Angélique , Mackova Anna , Escaich David , Clergereaux Richard , Raynaud Patrice , Stryhal Zdenek , Pavlik Jaroslav
Published: February 2006

Cover: AFM scans (5µm × 5µm) of 500 nm thick films as deposited on Si from processes a) RFICP (full vertical scale: 12.6 nm), b) MIRA (full vertical scale: 44.9 nm), and c) DECRP (full vertical scale: 27.7 nm). Further details can be found in the Full Paper by P. Supiot,* C. Vivien, A. Granier, A. Bousquet, A. Mackova, D. Escaich, R. Clergereaux, P. Raynaud, Z. Stryhal, and J. Pavlik on page 100.
X‐ray powder diffraction study of the Cu2Cd1–xMnxSnSe4 alloys
Authors: Sachanyuk V. P. , Olekseyuk I. D. , Parasyuk O. V.
Published: February 2006

The alloys of the Cu2CdSnSe4–Cu2MnSnSe4 system were investigated using the X‐ray powder method that showed the continuous solubility of the original system components at 670 K. The refinement of the crystal structures of Cu2MnSnSe4 (space group (SG) I&4macr;2m, a = 0.57362(4) nm, c = 1.14007(7) nm, c/a = 1.9875, RI = 0.0531, RP = 0.1186) and of the solid solution of Cu2Cd0.5Mn0.5SnSe4 composition (SG I&4macr;2m, a = 0.57935(2) nm, c = 1.14036(5) nm, c/a = 1.9683, RI = 0.0455, RP = 0.0902) was performed. It was established that Cd mixes statistically with Mn in its crystallographic position. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal development of microstructure and precipitation effects in Mg–10wt%Gd alloy
Authors: Čížek Jakub , Procházka Ivan , Smola Bohumil , Stulíková Ivana , Kužel Radomír , Matěj Zdeněk , Cherkaska Viktoria
Published: February 2006

Thermal effects on the microstructure and precipitation in Mg–10wt%Gd alloy were studied in this work. The role of lattice defects was investigated using positron annihilation spectroscopy. Studies of defects by positron annihilation were combined with X‐ray diffraction and microhardness measurements. Vacancies bound to Gd atoms were found in the homogenised sample quenched down to room temperature. Subsequently, clustering of Gd atoms takes place with increasing temperature. The Gd‐rich clusters represent precursors for further precipitates of the β″ phase. The formation of fine β″ phase particles leads to a maximum in the hardness. Vacancy‐like misfit defects are introduced by precipitation of β′ phase particles in the sample annealed to higher temperatures. A good correlation between the intensity of trapped positrons and the contribution by positrons annihilating Gd electrons was found. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reactive magnetron sputtering of highly (001)‐textured WS2−x films: Influence of Ne+, Ar+ and Xe+ ion bombardment on the film growth
Authors: Ellmer K. , Seeger S. , Sieber I. , Bohne W. , Röhrich J. , Strub E. , Mientus R.
Published: February 2006

Tungsten disulfide WS2 is a layer‐type semi‐conductor with an energy band gap and an absorption coefficient making it suitable as an absorber for thin film solar cells. In the article [1] WS2–x films were pre‐pared by reactive magnetron sputtering from a metallic tungsten target in Ar–H2S atmospheres.

The cover figure shows in situ energy‐dispersive X‐ray diffraction patterns for films deposited at different substrate potentials, i.e. for deposition conditions with ion assistance at different ion energies. These spectra and the corresponding SEM photographs of the film morphology show the strong influence of the ion energy on the film growth. The crystallographic struc‐ture of WS2–x is shown between the two SEM pictures.

The first author, Klaus Ellmer, is working at the Hahn‐Meitner‐Institut Berlin, Dept. of Solar Energy Research. His research fields are thin film deposition by reactive magnetron sputtering for solar cells, plasma characterization, in situ energy‐dispersive X‐ray diffraction and electronic transport in transpar‐ent conductive oxides.
Carbon nanotube – molecular resonant tunneling diode
Authors: Pandey Rajeev R. , Bruque Nicolas , Alam Khairul , Lake Roger K.
Published: February 2006

In the Rapid Research Letter [1] carbon nanotube (CNT) molecular resonant tunnel diodes (RTD) are proposed to complement bio‐assembled CNT field effect transistors. The cover figure is a schematic representation of a model CNT–pseudopeptide–CNT device in its relaxed structure with hydrogen passivation at the CNT ends. The device has been shown to exhibit the typical current–voltage response of an RTD.

The first author, Rajeev Pandey, works as a post‐doctoral researcher in the Laboratory for Terascale and Terahertz Electronics, headed by Roger Lake, at Riverside.

The current issue of physica status solidi (a) also contains the Feature Article “On the growth mechanisms of nanocrystalline diamond films” by Wilhelm Kulisch and Cyril Popov [2].
Optimal Abdominal Incision for Partial Hepatectomy: Increased Late Complications with Mercedes‐type Incisions Compared to Extended Right Subcostal Incisions
Authors: D’Angelica Michael , Maddineni Sridevi , Fong Yuman , Martin Robert C.G. , Cohen Michael S. , Ben‐Porat Leah , Gonen Mithat , DeMatteo Ronald P. , Blumgart Leslie H. , Jarnagin William R.
Published: February 2006

Introduction

The optimal abdominal incision for partial hepatectomy has not been established.

Methods

A prospective hepatobiliary surgery database was retrospective reviewed. Patients with Mercedes and extended right subcostal (ERSC) incisions were identified and compared.

Results

Between December 1991 and September 2001 a total of 1426 patients met the inclusion criteria. Among them, 856 (60%) had a Mercedes incision and 570 (40%) an ERSC incision. The two groups were well matched for demographics and operative variables. Perioperative morbidity and pulmonary complications were similar for the two groups as well. There was no difference in terms of early wound complications, although incisional hernias occurred in 9.8% of patients with a Mercedes incision compared to 4.8% of those with an ERSC incision (P = 0.0001.) On multivariate analysis, the incision type, along with gender, body mass index, and age, were significant predictors of incisional hernia.

Conclusions

An ERSC incision for partial hepatectomy provides adequate, safe access and is associated with fewer long‐term wound complications.
Correlations between Vitamin D Status and Biochemical/Clinical and Pathological Parameters in Primary Hyperparathyroidism
Authors: Özbey Neşe , Erbil Yeşim , Ademoğlu Evin , Özarmağan Selçuk , Barbaros Umut , Bozbora Alp
Published: February 2006

Background

To determine the prevalence of vitamin D deficiency and the effects of vitamin D status on parathyroid adenoma weight, clinical and biochemical indices in patients with primary hyperparathyroidism (pHPT) were studied.

Methods

Eighty patients with pHPT who underwent surgical treatment and in whom the presence of parathyroid adenoma were confirmed histopathologically were studied retrospectively from recorded data files. Patients were divided into three groups: patients with 25‐hydroxyvitamin D (25‐OHD) concentrations < 15 ng/ml (group 1, n = 44), patients with 25‐OHD concentrations > 15–25 ng/ml (group 2, n = 9), and patients with 25‐OHD concentrations > 26 ng/ml (group 3, n = 27). Serum calcium, phosphate, alkaline phosphatase, creatinine, and albumin levels and urinary calcium excretion were determined by auto‐analyzer. Plasma 25‐OHD and parathyroid hormone (PTH) levels were determined by immunoradiometric assay using commercially available kits.

Results

No statistically significant differences were observed with respect to serum calcium, phosphorus, albumin, and creatinine concentrations between these groups. Serum PTH, alkaline phosphatase concentrations, urinary calcium excretion, parathyroid adenoma weight, and postoperative sixth month PTH concentrations were significantly higher in group 1 patients than in group 2 and group 3 patients. Significant correlations were observed between parathyroid adenoma weight and serum 25‐OHD concentrations (r = −0.348, P = 0.020); parathyroid adenoma weight and urinary calcium excretion (r = 0.348, P = 0.021). Multiple regression analysis revealed that parathyroid adenoma weight, serum 25‐OHD, and preoperative PTH concentrations correlated independently and significantly with postoperative sixth month PTH concentrations.

Conclusions

Vitamin D deficiency leads to more severe bone disease, increased parathyroid tumor growth, and delayed postoperative recovery of parathyroid function in patients with primary hyperparathyroidism.
Community Social Organization, Parents, and Peers as Mediators of Perceived Neighborhood Block Characteristics on Delinquent and Prosocial Activities
Authors: Cantillon Dan
Published: February 2006

Research on contextual and neighborhood effects has grown exponentially over the past decade as researchers have reacknowledged that community matters. Although empirical findings have consistently documented the significant influence of neighborhood context, the field is just beginning to investigate the varied and multiple pathways through which this influence is transmitted. The current study found support for both a direct and indirect influence of perceived neighborhood structural characteristics (i.e., neighborhood stability, income), measured at the block level, on neighborhood and youth outcomes. Directly, perceived neighborhood advantage led to significantly lower neighborhood rates of official delinquency and higher rates of prosocial activity. Indirectly, perceived neighborhood advantage significantly impacted outcomes by influencing more proximal constructs such as community social organization, informal social control, parenting practices, and affiliation with delinquent peers. Different pathways were significant across neighborhood and youth outcomes, yet perceived neighborhood advantage, in particular neighborhood stability, consistently exerted substantial effects, highlighting the need for more comprehensive and multilevel prevention efforts.
Reaching Higher in Community Psychology: Social Problems, Social Settings, and Social Change
Authors: Weinstein Rhona S.
Published: February 2006

Forty years after the founding of community psychology, we have yet to deliver on the full promissory note of our birth, where we were poised to address social problems, social settings, and social change. Despite some success, we are at risk for selling ourselves short, for dying out in the discipline of psychology, and for failing to improve the common good. Given changes in demographics and in the safety net, the problem of entrenched disparities is even more urgent—in perception of the other, in the provision of opportunities for development, and in outcomes. Envisioning and enabling will be critical as we work with unified purpose toward a cumulative science where failure will not be predictable.
The Importance of Written Information Packages in Support of Case‐Finding Within Families at Risk for Inherited High Cholesterol
Authors: van den Nieuwenhoff Hélène W. P. , Mesters Ilse , Nellissen Joyce J. T. M. , Stalenhoef Anton F. , de Vries Nanne K.
Published: February 2006

Inherited High Cholesterol is treatable, but highly underdiagnosed. To detect undiagnosed blood relatives at a presymptomatic stage, in the Netherlands written information packages are available to facilitate family communication. To investigate the role of those packages in the detection of carriers, we conducted a qualitative evaluation (plus‐minus method combined with semistructured interviews with index patients and relatives). Our data suggest that interviewees approved the family approach for finding carriers, although reluctantly. The packages aided family disclosure by reducing hesitation. However, index patients only informed first‐degree relatives and generally communicated the risk only once. This may be due to the cultural context and a limited understanding of genetics. For relatives the packages served as a cue to action and as a legitimation to gain access to a diagnostic cholesterol test. Despite the value of these written materials, they should not be used as the only communication between index patient and relatives.
Musculoskeletal Imaging Update: Current Applications of Advanced Imaging Techniques to Evaluate the Early and Long-Term Complications of Patients with Orthopedic Implants
Authors: Sofka Carolyn M. , Potter Hollis G. , Adler Ronald S. , Pavlov Helene
Published: February 2006

Technical advances in imaging have increased their applicability to diagnosing conditions of the musculoskeletal system, especially in the postoperative setting, where traditionally metallic artifacts have hindered evaluation. Advances in computed tomography (CT), magnetic resonance (MR) imaging, ultrasound, and nuclear medicine have resulted in improved overall image quality. Specific modifications of imaging parameters, especially in CT and MRI, have improved the radiologist's ability to diagnose potential hardware complications such as loosening and osteolysis. Sonography can evaluate the periprosthetic soft tissues and enables both diagnostic information and therapeutic treatment at the same sitting. Lastly, diagnostic scintigraphic applications such as positron emission tomography (PET) have increased specificity in diagnosing potential infection in the arthroplasty setting. This review discusses some of the current applications of CT, MRI, ultrasound, and nuclear medicine in evaluating the postoperative orthopedic patient, concentrating on the appropriate imaging evaluation for the painful arthroplasty patient.
Supplementary research of clinoptilolite-rich tuff composites after adsorption trials using the XPS technique
Authors: Chmielewská Eva , Tylus Wlodzimierz , Morvová Marcela
Published: February 2006

The paper deals with fabrication of carbonized and hydrophobized clinoptilolite-rich tuff using organic carbon rich substances, here particularly starch and waste vegetable residues, which were pyrolytically combusted and covered the external zeolite surface. Hydrophobization of the zeolite external surface was accomplished by octadecylammonium surfactant. Both surface modified clinoptilolite-rich tuffs were tested and compared with each other with regard to removal of organic (phenol) and inorganic (chromate, arsenate) pollutants from aqueous solutions. These elaborated composites with surface adsorbed pollutant species were analysed by X-ray photoelectron spectroscopy (XPS).
Assessment of the impact of a phosphatic fertilizer plant on the adjacent environment using fuzzy logic
Authors: Szczepaniak K. , Sârbu C. , Astel A. , Raińska E. , Biziuk M. , Culicov O. , Frontasyeva M.V. , Bode P.
Published: February 2006

The impact of a phosphatic fertilizer plant on the adjacent environment was examined. Selected rare earth elements, heavy metals and metalloids were determined in substrates and products, waste by-product, and grass and soil samples. Concentration gradients of elements in grass and soil samples along the southerly and easterly directions were examined and compared with the content of interior soil and grass samples, substrates, and products. Results were compared with available data on soil permissible element concentration levels. Two fuzzy principal component analysis (FPCA) methods for robust estimation of principal components were applied and compared with classical PCA. The efficiency of the new algorithms is illustrated. The investigation explored the impact of the plant on the adjacent environment. The most reliable results, in good agreement with types of samples, were produced using the FPCA-O algorithm
Environmental and economic comparison of waste solvent treatment options
Authors: Benko Tamas , Szanyi Agnes , Mizsey Peter , Fonyo Zsolt
Published: February 2006

The sustainable development and consumption need more efficient use of natural resources. As a consequence, the use of industrial solvents demands their recovery instead of end-of-pipe treatment. It is not always clear, however, which treatment alternative should be applied. Based on an industrial case study, the environmental and economic evaluation and comparison of the treatment alternatives of a non-ideal solvent mixture containing azeotropes is investigated for determining the preferable option. For the recovery of the industrial solvent mixture, two different separation alternatives are evaluated: a less effective alternative and a novel design based on hybrid separation tools. An end-of-pipe treatment alternative, incineration, is also considered and the split of the solvent mixtures between recovery and incineration is investigated. The environmental evaluation of the alternatives is carried out using ‘Eco-indicator 99 life-cycle impact assessment methodology’. Economic investigation is also accomplished. The economic features clearly favour the total recovery, however, the environmental evaluation detects that if a recovery process of low efficiency is applied, its environmental burden can be similar or even higher than that of the incineration. This motivates engineers to design more effective recovery processes and reconsider the evaluation of process alternatives at environmental decision making.
Improved QSAR modeling of anti-HIV-1 acivities by means of the optimized correlation weights of local graph invariants
Authors: Marino Damián , Castro Eduardo , Toropov Andrey
Published: February 2006

We report the results derived from the use of molecular descriptors calculated with the correlation weights (CWs) of local graph invariants for modeling of anti-HIV-1 potencies of two groups of reverse transcriptase inhibitors. The presence of different chemical elements in the molecular structure of the inhibitors and the Morgan extended connectivity values of zeroth-, first-, and second order have been examined as local graph invariants in the labeled hydrogen-filled graphs. We have computed via Monte Carlo optimization procedure the values of CWs which produce the largest possible correlation coefficient between the numerical data on the anti-HIV-1 potencies and those values of the descriptors on the training set. The model of the anti-HIV-1 activity obtained with compounds of training set by means of optimization of correlation weights of chemical elements present together with Morgan extended connectivity of first order makes up a sensible model for a satisfactory prediction of the endpoints of the compounds belonging to the test set.
Oxovanadium(IV) complexes of bromo-and methoxy substituted N1,N4-diarylidene-S-methylthiosemicarbazones
Authors: Demirci Tülay. , Köseoğlu Yüksel , Güner Sadik , Ülküseven Bahri
Published: February 2006

Four new oxovanadium(IV) compounds were prepared by template reaction of salicyl-, 5-bromosalicyl-and 3-methoxysalicyl-aldehyde S-methylthiosemicarbazones with 2-hydroxy-, 5-bromo-2-hydroxy-and 3-methoxy-2-hydroxy-benzaldehyde in various combinations. The compounds were isolated as stable solid compounds with general formula [VO(L)] and characterized by elemental analysis, conductivity and magnetic measurements, electronic, IR and EPR spectroscopy. The X-band EPR signals recorded from powder forms of all samples have a single asymmetric line shape and theoretical fit studies proved the presence of axial symmetry around the paramagnetic vanadium ions. The anisotropic Lande splitting factors take values of g‖ < g⊥ < ge = 2.0023. Orbital energy levels for magnetic electrons were determined from theoretically well fitted Spin Hamiltonian parameters. The EPR spectra recorded from solution forms almost have isotropic character.
Two-step synthesis of high aspect ratio gold nanorods
Authors: Mortier Tom , Persoons André , Verbiest Thierry
Published: February 2006

We describe a very simple, two-step synthetic method to prepare gold nanorods with extremely high aspect ratios (> 20) and average lengths of more than 1000 nm. The method is based on a seed-mediated growth in presence of the surfactant cetyltrimethylammonium bromide. The length and aspect ratios of the nanorods can be manipulated by varying the surfactant concentration.
Phase formation and microstructure in Re1-x CaxBa2Cu3Oz (Re=Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics
Authors: Stoyanova-Ivanova A.K. , Terzieva S.D. , Staneva A.D. , Mikli V. , Traksmaa R. , Dimitriev Y.B. , Kovachev V.T.
Published: February 2006

We have investigated the influence of Ca-substitution and different rare earths on the microstructure of RE1-x
CaxBa2Cu3O7-δ
(RE= Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics. Scanning electron microscopy, X-ray microanalysis and energy dispersive spectroscopy have been used to study the microstructure and the chemical composition of the samples. A correlation was established between the polycrystalline microstructure and phase formation depending on the additive content. We observed that calcium is distributed uniformly in the crystals. The formation of minor impurity phases improved the sintering conditions.
Density and surface tension of the systems CaO-FeO-Fe2O3-MgO, CaO-FeO-Fe2O3-ZnO and CaO-Fe2O3-Cu2O
Authors: Vadász Pavol , Havlík Milan , Daněk Vladimír
Published: February 2006

The density and surface tension of melts of the systems CaO-FeO-Fe2O3 MgO at the temperature 1623 K, CaO-FeO-Fe2O3-ZnO at 1573 K, and CaO-Fe2O3-Cu2O at 1573 K were determined using the maximum bubble pressure method. The molar volume, the excess molar volume, and the excess surface tension were calculated on the basis of the obtained data. From these properties information on the interactions of components and possible chemical reactions between them was obtained. Due to the absence of silica and the low concentration of other network-forming oxides, only isolated FeO45− tetrahedra and the CaO·FeO ionic pairs are formed in these basic melts, the donor of the oxygen atoms being either CaO, FeO, or both CaO+FeO oxides. Even the observed ternary interactions may be attributed to the formation of the anions FeO45− only.
AFM study of complement system assembly initiated by antigen-antibody complex
Authors: Ramanaviciene Almira , Snitka Valentinas , Mieliauskiene Rasa , Kazlauskas Rolandas , Ramanavicius Arunas
Published: February 2006

The shape and size of complement system C1 components assembled on a SiO2 surface after classical activation by antigen-antibody complex was determined by tapping mode atomic force microscopy (AFM). The SiO2 substrate was silanized and bovine leukemia virus proteins gp51 were covalently bound to the SiO2 substrate. Self-assembly of complement system proteins was investigated by AFM. Uniform coating of silanized surface by gp51 proteins was observed by AFM. After incubation of gp51 coated substrate in anti-gp51 antibody containing solution, Ag-Ab complexes were detected on the substrate surface by AFM. Then after treatment of Ag-Ab complex modified substrate by guinea-pig blood serum containing highly active complement system proteins for 3 minutes and 30 minutes features 2–3 times and 5–8 times higher in diameter and in height if compared with those observed after formation of Ag-Ab complex, were observed respectively on the surface of SiO2. This study revealed that AFM might be applied for the imaging of complement system assembly and provides valuable information that can be used to complement other well-established techniques.
Exact laws for sums of ratios of order statistics from the Pareto distribution
Authors: Adler André
Published: February 2006

Consider independent and identically distributed random variables {X
nk, 1 ≤ k ≤ m, n ≤ 1} from the Pareto distribution. We select two order statistics from each row, X
n(i) ≤ X
n(j), for 1 ≤ i < j ≤ = m. Then we test to see whether or not Laws of Large Numbers with nonzero limits exist for weighted sums of the random variables R
ij = X
n(j)/X
n(i).
On the doubly connected domination number of a graph
Authors: Cyman Joanna , Lemańska Magdalena , Raczek Joanna
Published: February 2006

For a given connected graph G = (V, E), a set
$$D \subseteq V(G)$$
is a doubly connected dominating set if it is dominating and both 〈D〉 and 〈V (G)-D〉 are connected. The cardinality of the minimum doubly connected dominating set in G is the doubly connected domination number. We investigate several properties of doubly connected dominating sets and give some bounds on the doubly connected domination number.
Ordinary differential equations and their exponentials
Authors: Kock Anders , Reyes Gonzalo
Published: February 2006

In the context of Synthetic Differential Geometry, we discuss vector fields/ordinary differential equations as actions; in particular, we exploit function space formation (exponential spaces) in the category of actions.
Hitting distributions domination and subordinate resolvents; an analytic approach
Authors: Boboc Nicu , Bucur Gheorghe
Published: February 2006

We give an analytic version of the well known Shih's theorem concerning the Markov processes whose hitting distributions are dominated by those of a given process. The treatment is purely analytic, completely different from Shih's arguments and improves essentially his result (in the case when the given processes are transient
Modulation of the epithelial barrier by dexamethasone and prolactin in cultured Madin—Darby canine kidney (MDCK) cells
Authors: Peixoto E.B.M.I. , Collares‐Buzato C.B.
Published: February 2006

Glucocorticoids and prolactin (PRL) have a direct effect on the formation and maintenance of tight junctions (TJs) in cultured endothelial and mammary gland epithelial cells. In this work, we investigated the effect of a synthetic glucocorticoid dexamethasone (DEX) and PRL on the paracellular barrier function in MDCK renal epithelial cells. DEX (4 μM) + PRL (2 μg/ml) and DEX alone increased significantly the transepithelial electrical resistance after chronic treatment (4 days) of confluent MDCK monolayers or after 24 h treatment of subconfluent monolayers. Immunoblotting and immunocytochemistry revealed no changes in the expression and distribution of TJ‐associated proteins occludin, ZO‐1 and claudin‐1 in confluent monolayers after hormone addition. However, a marked increase in junctional content for occludin and ZO‐1 with no changes in their total expression was observed in subconfluent MDCK monolayers 24 h exposed to DEX or DEX + PRL. No change in cell proliferation/growth was detected at subconfluent conditions following hormone treatment. An increase in the total number of viable cells was observed only in confluent MDCK monolayers after exposure to DEX + PRL suggesting that the main effect of these hormones on already established barrier may be associated with the inhibition of cell death. In conclusion, our data suggest that these hormones (specially dexamethasone) have an effect on TJ structure and function only during the formation of MDCK epithelial barrier by probably modulating the localization, stability or assembly of TJ proteins to membrane sites of intercellular contact.
Involvement of caspase‐3 pathway in anti‐apoptotic action of methionine enkephalin on CEM × 174 cells in prolonged infection with simian immunodeficiency virus in vitro
Authors: Xu Jin , Xin Shuqin , Li Hui , Liu Lin , Xia Weiyi , Li Pingfeng , Liu Xinhua , Li Gang
Published: February 2006

The roles of methionine enkephalin, as an immunomodulator, on immunodeficiency virus‐induced apoptosis of lymphocytes during prolonged infection are still unclear. In the present study, we evaluated the effects of methionine enkephalin on the viability, the profile of cell cycle and apoptosis, as well as the expression of apoptosis‐related genes in CEM × 174 cells infected with simian immunodeficiency virus for 72 h. Our data demonstrated that methionine enkephalin maintains the viability of cells during the period of prolonged infection. Following co‐incubation with the virus, CEM × 174 cells were arrested at S phase, with increased mortality as a result of apoptosis. Methionine enkephalin could abolish virus‐induced over‐expression of caspase‐3. Taken together all findings, we conclude that methionine enkephalin may maintain the viability of SIV‐infected cells via suppressing the expression of caspase‐3, which may have clinical implications in opioid peptide therapy for AIDS.
The effect of altering haemodynamics on the plasma concentrations of natriuretic peptides in heart failure
Authors: Larsen A.I. , Dickstein K. , Ahmadi N.S. , Aarsland T. , Kvaløy J.T. , Hall C.
Published: February 2006

Background

Natriuretic peptide levels reflect haemodynamics in patients with heart failure and may serve as biochemical markers of cardiac filling pressures. The purpose of this study was to detect differences in the kinetic profile between atrial natriuretic peptide (ANP), B‐type natriuretic peptide (BNP) and their N‐terminal fragments N‐ANP and N‐BNP, in response to rapid and persistent vasodilatation.

Methods

Sixteen men and four women aged 63.0 ± 10.4 (mean ± S.D.) with symptomatic congestive heart failure (NYHA III) and pulmonary capillary wedge pressure (PCWP) > 18 mm Hg, received a 24‐h infusion of nitroglycerin (N= 8) or nicorandil (N= 12). A reduction of PCWP was achieved for the duration of the study. Natriuretic peptides were measured by radioimmunoassay at baseline, 1, 3, 6, 12 and 24 h.

Results

PCWP and right atrial pressure fell rapidly and then increased modestly. ANP and N‐ANP demonstrated a similar pattern. In contrast, BNP and N‐BNP levels fell steadily throughout the observation period. This was accompanied by a continuous reduction of systemic vascular resistance (SVR). PCWP was highly correlated to the levels of all the natriuretic peptides. Using alongitudinal regression modelevaluating responses over time, we found separate, significant relationships between all peptides and haemodynamic variables

Conclusion

The atrial natriuretic peptides reflect rapid changes in filling pressures while the B‐type peptides respond much slower. B‐type peptides are less sensitive to short‐term changes in filling pressures, but should reflect changes in SVR better during vasodilator therapy.
Biventricular versus right ventricular pacing decreases immune activation and augments nitric oxide production in patients with chronic heart failure
Authors: Rubaj Andrzej , Ruciński Piotr , Rejdak Konrad , Oleszczak Krzysztof , Duma Dariusz , Grieb Paweł , Kutarski Andrzej
Published: February 2006

Introduction

Immune system activation and oxidative stress are involved in the pathogenesis of heart failure (HF). We aimed to test the hypothesis that upgrading from right ventricular pacing (RVp) to biventricular pacing (BiVp) can counteract these phenomena.

Methods

28 HF patients, with BiVp were switched to RVp for one week, and then returned to BiVp. Immediately prior to, and 48 h after the return to BiVp, left ventricular (LV) systolic function was evaluated by echocardiography, and serum N‐terminal pro‐brain natriuretic peptide (NTproBNP), C‐reactive protein (CRP), tumor necrosis factor alpha (TNF‐α), interleukin 6 (IL6), nitric oxide metabolites (NOx) and malondialdehyde (MDA) were assayed.

Results

LV systolic function significantly improved 48 h after switching from RVp to BiVp: Ao‐VTI (p < 0.001), SV (p < 0.001) and CO (p < 0.001), and mitral regurgitation significantly decreased (p = 0.003). At the same time, indices of peripheral immune activation decreased: TNF‐α (p = 0.02) and IL6 (p < 0.001). MDA decreased (p < 0.001), whereas NOx increased (p = 0.04). NTproBNP and CRP did not change. In addition, in “responders” (i.e. CO increase > 10% during BiVp vs. RVp) NTproBNP decreased and NOx increased. However, during BiVp, the decreases in TNF‐α, IL6, and MDA occurred both in responders and in non‐responders and were accompanied by a reduction in mitral regurgitation.

Conclusion

The beneficial effect of BiVp compared to RVp extends beyond improving cardiac haemodynamics and comprises a decrease in immune activation accompanied by an increase in serum NOx and decrease in serum MDA.
Localization of SP‐ and CGRP‐immunopositive nerve fibers in the hip joint of patients with painful osteoarthritis and of patients with painless failed total hip arthroplasties
Authors: Saxler Guido , Löer Franz , Skumavc Marc , Pförtner Jörg , Hanesch Ulrike
Published: February 2006

Using immunohistochemical methods we determined the presence of SP‐ and CGRP‐immunopositive nerve fibers in the hip joint of patients with femoral neck fracture (controls, group 1), painful osteoarthritis (group 2), and painless failed total hip arthroplasties (group 3). Immunoreactive nerve fibers were found in the soft tissue of the fossa acetabuli as well as in the subintimal part of the synovial layer in the hip joint capsule of groups 1 and 2. In the capsule of controls the innervation density had a median of 5.7 fibers/cm2 for CGRP‐ir and 3.2 fibers/cm2 for SP‐ir afferents. In the osteoarthritic group, the density significantly increased to a median of 15.6 fibers/cm2 for CGRP‐ir and 8.2 fibers/cm2 for SP‐ir neurons (p = 0.05). Patients with failed hip arthroplasties completely lacked these neuropeptide containing afferents. Innervation density in the fossa acetabuli of osteoarthritc patients showed a median of 14.1 fibers/cm2 for CGRP‐ir and 5.9 fibers/cm2 for SP‐ir afferents. From these data we assume that the hip joint capsule and the soft tissue of the fossa acetabuli are important triggers of nociception. This is supported by the fact, that patients with loosened total hip arthroplasties, where we failed to detect SP‐ and CGRP‐immunoreactive fibers, did not feel pain.

The upregulation of SP‐ and CGRP‐positive neurons in response to arthritic stages suggests a mechanism involving neuropeptides in the maintenance of a painful degenerative joint disease and in mediating noxious stimuli from the periphery. Furthermore, these findings help to explain clinical observations, such as effectiveness of local therapy to control hip pain with intraarticular injection, synovectomy and denervation procedures.