bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wobbles, humps and sudden jumps: a case study of continuity, discontinuity and variability in early language development
Authors: van Dijk Marijn , van Geert Paul 
Published: February 2007

AbstractCurrent individual‐based, process‐oriented approaches (dynamic systems theory and the microgenetic perspective) have led to an increase of variability‐centred studies in the literature. The aim of this article is to propose a technique that incorporates variability in the analysis of theshapeof developmental change. This approach is illustrated by the analysis of time serial language data, in particular data on the development of preposition use, collected from four participants. Visual inspection suggests that the development of prepositions‐in‐contexts shows a characteristic pattern of two phases, corresponding with a discontinuity. Three criteria for testing such discontinuous phase‐wise change in individual data are presented and applied to the data. These are: (1) the sub‐pattern criterion, (2) the peak criterion and (3) the membership criterion. The analyses rely on bootstrap and resampling procedures based on various null hypotheses. The results show that there are some indications of discontinuity in all participants, although clear inter‐individual differences have been found, depending on the criteria used. In the discussion we will address several fundamental issues concerning (dis)continuity and variability in individual‐based, process‐oriented data sets. Copyright © 2007 John Wiley & Sons, Ltd.
Hepatotoxic effect of cyclosporin A in the mitochondrial respiratory chain
Authors: Rodríguez Lilia Cristina De la Cruz , Araujo Carmen Rosa , Posleman Sara Emilia , Rey María del Rosario 
Published: February 2007

AbstractCyclosporin A (CyA), a potent immunosuppressant, was used to determine the hepatotoxic effect in long‐term treatments. Male Wistar rats were used in these experiments. They were given CyA chronically at doses used in patients for 120 days, and at doses of 5, 10, 15 and 20 mg kg−1day−1. These doses amount to CyA values in blood of 200 ± 24, 314 ± 40, 445 ± 33 and 598 ± 53 ng ml−1, respectively. A significant increase in glutamate dehydrogenase (GLDH) was found in the groups treated with 15 and 20 mg kg−1day−1, which would point to mitochondria as the potential target of the toxic action of CyA. The mitochondrial respiratory chain of rat livers was studied in enzyme complexes I and II. Enzyme complex I was determined by spectrophotometry at 340 nm using NADH oxidase with the respirable substrate 10 mmNADH; enzyme complex II was determined by monitoring succinate dehydrogenase by oxymetry using the respirable substrate 10 mmsuccinate. The results show the inhibition of NADH oxidase in the groups treated with 10, 15 and 20 mg kg−1day−1, an effect dependent both on time and on CyA concentration. Enzyme complex II showed a decrease in oxygen consumption. These findings were confirmed by histological studies (hematoxylin‐eosin technique).Conclusions: Long‐term treatment with CyA at doses of 15 and 20 mg kg−1day−1, amounting to concentrations in blood of 445 ± 33 and 598 ± 53 ng ml−1, causes alterations in the mitochondria, revealed by the increase in serum GLDH and by the functional alteration of enzyme complexes I and II of the mitochondrial respiratory chain. Copyright © 2007 John Wiley & Sons, Ltd.
Role of nuclear factor‐kappa B activation in the adverse effects induced by air pollution particulate matter (PM2.5) in human epithelial lung cells (L132) in culture
Authors: Dagher Zeina , Garçon Guillaume , Billet Sylvain , Verdin Anthony , Ledoux Frédéric , Courcot Dominique , Aboukais Antoine , Shirali Pirouz 
Published: February 2007

AbstractABSTRACT: To contribute to improving knowledge on the adverse health effects induced by particulate matter (PM) air pollution, an extensive investigation was undertaken of the underlying mechanisms of action activated by PM2.5 air pollution collected in Dunkerque, a strongly industrialized French seaside city. Their chemical and physical characteristics have been previously determined, and earlier in vitro short‐term studies have shown them to cause dose‐dependent and time‐dependent oxidative damage, gene expression and protein secretion of inflammatory mediators, and apoptotic events in human lung epithelial cells (L132) in culture. Hence, this work studied the activation of nuclear factor‐kappa B (NF‐κB)/inhibitory kappa B (IκB) by Dunkerque city PM2.5 in these target cells, by determination of phosphorylated p65 and phosphorylated IκBα protein levels in cytoplasmic extracts, and p65 and p50 DNA binding in nuclear extracts. In PM‐exposed L132 cells, there were concentration‐ and/or time‐dependent increases in nuclear p65 and cytoplasmic IkB‐α phosphorylation, and nuclear p65 and p50 DNA binding. Taken together, these results showed that Dunkerque city PM2.5 were involved in the activation of the NF‐κB/IκB complex, notably through the occurrence of oxidative stress conditions, and, therefore, in the gene expression and protein secretion of inflammatory mediators in target L132 cells. Hence, these findings suggested that the activation of the NF‐κB/IκB complex preceded cytotoxicity in Dunkerque city PM‐exposed L132 cells. Copyright © 2007 John Wiley & Sons, Ltd.
Paraoxon has only a minimal effect on pralidoxime brain concentration in rats
Authors: Petroianu G. A. , Lorke D. E. , Hasan M. Y. , Adem A. , Sheen R. , Nurulain S. M. , Kalasz H. 
Published: February 2007

AbstractClinical experience with oximes, cholinesterase reactivators used in organophosphorus poisoning, has been disappointing. Their major anatomic site of therapeutic action and their ability to pass the blood–brain barrier (BBB) are controversial. Although their physico‐chemical properties do not favour BBB penetration, access of oximes to the brain may be facilitated by organophosphates. The effect of the organophosphate paraoxon (POX) on pralidoxime (2‐PAM) brain entry was therefore determined. Rats either received 50 µmol 2‐PAM only (G1) or additionally 1 µmol POX (≈ LD75) (G2). Three animals each were killed after 5, 15, 30, 60, 90, 120, 180, 240, 360, 480 min, and 2‐PAM concentrations in the brain and plasma were measured using HPLC. Moreover, the effect of brain perfusion with isotonic saline on subsequent 2‐PAM measurements was assessed.The maximal 2‐PAM concentration (Cmax) in G1 brain was 6% of plasma Cmax, while in G2 brains it was 8%. Similarly, the ratio of the area under the curve (AUC) brain to plasma was 8% in G1 and 12% in G2. Brain tmax (15 min) was slightly higher than plasma tmax (5 min). The AUC of plasma 2‐PAM did not differ between G1 and G2. However, in G1, AUC brain was significantly lower than in G2, the differences probably being clinically irrelevant. In perfused brains, 2‐PAM concentrations were very close to those of non‐perfused brains. The results indicate that brain penetration of 2‐PAM is poor and that organophosphates only have a modest effect on 2‐PAM BBB penetration. Brain perfusion does not significantly alter 2‐PAM measurements and is therefore considered unnecessary. Copyright © 2007 John Wiley & Sons, Ltd.
Chitosan–thioglycolic acid conjugate: An alternative carrier for oral nonviral gene delivery?
Authors: Martien Ronny , Loretz Brigitta , Thaler Marlene , Majzoob Sayeh , Bernkop‐Schnürch Andreas 
Published: February 2007

AbstractRegarding safety concerns, nonviral gene delivery vehicles that have the required efficiency and safety for use in human gene therapy are being widely investigated. The aim of this study was to synthesize and evaluate a thiolated chitosan to improve the efficacy of oral gene delivery systems. Thiolated chitosan was synthesized by introducing thioglycolic acid (TGA) to chitosan via amide bond formation mediated by a carbodiimide. Based on this conjugate, nanoparticles with pDNA were generated at pH 4.0 and 5.0. Cytotoxicity of the thiolated chitosan/pDNA nanoparticles on Caco‐2 cells was evaluated. The diameter of thiolated chitosan/pDNA nanoparticles was in the range of 100–200 nm. The zeta potential was determined to be 5–6 mV. Due to stability toward nucleases, the transfection rate of thiolated chitosan/pDNA nanoparticles was fivefold higher than that of unmodified chitosan/pDNA nanoparticles. Lactate dehydrogenase tests for thiolated chitosan/pDNA (pH 4.0 and 5.0) showed that (3.79 ± 0.23)% and (2.9 ± 0.13)% cell damage. According to these results, thiolated chitosan represents promising excipients for preparation DNA nanoparticles in nonviral gene delivery system. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Mid infrared microspectroscopic mapping and imaging: A bio‐analytical tool for spatially and chemically resolved tissue characterization and evaluationof drug permeation within tissues
Authors: Garidel Patrick , Boese Matthias 
Published: February 2007

AbstractThe combination of the two classical biophysical methods, microscopy and infrared spectroscopy, has led to the development of a potent analytical technology termed infrared microspectroscopy. It combines high lateral resolution as obtained by microscopy and the chemical identification of the sample components by infrared spectroscopy. The two approaches mainly utilized in microspectroscopy are the mapping and the imaging techniques, which are introduced and presented. Especially, since the development of so called focal plane array detectors, which are implemented in the imaging methods (microspectroscopic imaging) has become a promising bio‐analytical tool for ultrastructural medical diagnostics, due to the fact that the time required for analyzing a sample has been reduced dramatically and the lateral resolution improved to ∼4 μm. Mid infrared microscopy allows a direct access to spatially resolved molecular and structural information of the analyzed area. The image contrast is generated on the basis of the tissue's intrinsic biochemical composition. The current investigation shows how mid infrared microspectroscopic mapping and imaging is used for the bio‐analytical characterization and identification of specific molecular components of a tissue sample at high lateral resolution of a few microns (approaching the mid infrared diffraction limit). Furthermore, the potential of these methods for monitoring the penetration and distribution of drugs within biological tissues are presented. Due to the fact, that mid infrared microspectroscopy is a noninvasive, nondestructive technique for the analyzed sample, requiring no complicated and time consuming staining procedures, it is a convenient method for histological and pathological investigations, allowing the generation of a huge amount of biochemical information not yet available with other nonvibrational techniques. The strength of the presented microscopic technique is the fact that the infrared images are directly comparable to outcomes of classical histological staining procedures and can be interpreted by nonspectroscopists. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
A combined atomic force/fluorescence microscopy technique to select aptamers in a single cycle from a small pool of random oligonucleotides
Authors: Peng Lu , Stephens Bryan J. , Bonin Keith , Cubicciotti Roger , Guthold Martin 
Published: February 2007

AbstractWe develop a method, which utilizes a combined atomic force microscope (AFM)/fluorescence microscope and small copy number polymerase chain reaction (PCR), to affinity‐select individual aptamer species in a single cycle from a small pool of random‐sequence oligonucleotides (oligos). In this method, a library of small beads, each of which is functionalized with fluorescent oligos of different sequences, is created. This library of oligo‐functionalized beads is flowed over immobilized target molecules on a glass cover slip. High‐affinity target‐specific aptamers bind tightly to the target for prolonged periods and resist subsequent washes, resulting in a strong fluorescence signal on the substrate surface. This signal is observed from underneath the sample via fluorescence microscopy. The AFM tip, situated above the sample, is then directed to the coordinates of the fluorescence signal and is used to capture a three‐dimensional high‐resolution image of the surface‐bound bead and to extract the bead (plus attached oligo). The extracted oligo is PCR‐amplified, sequenced, and may then be subjected to further biochemical analysis. Here, we describe the underlying principles of this method, the required microscopy instrumentation, and the results of proof‐of‐principle experiments. In these experiments, we selected aptamers in eight trials from a binary pool containing a 1:1 mixture of thrombin aptamer oligo and a nonsense oligo. In each of the eight trials, the positive control aptamer was successfully detected, imaged, extracted, and characterized by PCR amplification and sequencing. In no case was the nonsense oligo selected, indicating good selectivity at this early stage of technology development. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Inhibitory effects of blueberry extract on the production of inflammatory mediators in lipopolysaccharide‐activated BV2 microglia
Authors: Lau Francis C. , Bielinski Donna F. , Joseph James A. 
Published: February 2007

AbstractSustained microglial activation in the central nervous system (CNS) has been extensively investigated in age‐related neurodegenerative diseases and has been postulated to lead to neuronal cell loss in these conditions. Recent studies have shown that antiinflammatory drugs may suppress microglial activation and thus protect against microglial overactivation and subsequent cell loss. Research also suggests that fruits such as berries may contain both antioxidant and antiinflammatory polyphenols that may be important in this regard. Our previous research showed that blueberry extract was effective in preventing oxidant‐induced calcium response deficits in M1 (muscarinic receptor)‐transfected COS‐7 cells. Extrapolating from these findings, the current study investigated the effect of blueberry extract on preventing inflammation‐induced activation of microglia. Results indicated that treatments with blueberry extract inhibited the production of the inflammatory mediator nitric oxide (NO) as well as the cytokines interleukin‐1β and tumor necrosis factor‐α, in cell conditioned media from lipopolysaccharide (LPS)‐activated BV2 microglia. Also, mRNA and protein levels of inducible nitric oxide synthase and cyclooxygenase‐2 in LPS‐activated BV2 cells were significantly reduced by treatments with blueberry extract. The results suggest that blueberry polyphenols attenuate inflammatory responses of brain microglia and could be potentially useful in modulation of inflammatory conditions in the CNS. © 2007 Wiley‐Liss, Inc.
Risk of venous thromboembolism in patients undergoing cancer surgery and options for thromboprophylaxis
Authors: Bergqvist David 
Published: February 2007

AbstractPatients with cancer have an increased risk of developing venous thromboembolism (VTE) due to a hypercoagulable state associated with malignancy. This risk is further complicated in patients undergoing cancer‐related surgery due to immobility, other cancer treatments, and biologic changes associated with surgery. Despite this relatively high risk of VTE, many patients are not prescribed adequate prophylaxis in the pre‐ or post‐operative periods. This article reviews available measures for thromboprophylaxis in light of current guidelines. J. Surg. Oncol. 2007;95:167–174. © 2007 Wiley‐Liss, Inc.
Alter Mut und neue Märkte – Ein Gespräch mit dem ehemaligen Vorstandsvorsitzenden der Lambda Physik AG Dr. Dirk Basting
Authors: Basting Dirk 
Published: February 2007

AbstractVor über 30 Jahren hat Dirk Basting in Göttingen zusammen mit Bernd Steyer die Laserfirma Lambda Physik gegründet. Aus dem Zweimannbetrieb von 1971 ist inzwischen ein Aktienunternehmen und ein weltweit führender Anbieter von UV‐Lasern geworden. Mit dem ehemaligen Vorstandsvorsitzenden der Lambda Physik AG Dirk Basting sprach Andreas Thoß. Holger Kock hat den Dialog zusammengefasst.
Electrochemical impedance spectroscopic studies of titanium and its alloys in saline medium
Authors: Tamilselvi S. , Murugaraj R. , Rajendran N. 
Published: February 2007

AbstractThe influence of potential on electrochemical behaviour of pure Ti, Ti‐6Al‐7Nb, and Ti‐6Al‐4V ELI alloy under saline conditions were investigated by electrochemical impedance spectroscopy (EIS). All measurements were carried out in saline solution (0.9% NaCl) at different impressed potentials (corrosion potential (Ecorr), 0 mV (SCE) and + 500 mV (SCE)) for 1 h. The experimental results were compared with those obtained by potentiodynamic polarization curves. The corrosion current densities obtained for the titanium alloys showed lower values than for pure Ti, indicating the formation of a stable passive film with time. Electrochemical impedance spectroscopic studies indicated that the resistance of the passive film increased with the impressed potential. The impedance spectra were fitted using a non‐linear least square (NLLS) fitting procedure. The magnitude of the corrosion resistance of titanium alloys under saline solution was compared and results are presented.
Quantification of nepetalactones in catnip (Nepeta cataria L.) by HPLC coupled with ultraviolet and mass spectrometric detection
Authors: Wang Mingfu , Cheng Ka‐Wing , Wu Qingli , Simon James E. 
Published: February 2007

AbstractNepetalactones, the major chemical components of catnip (Nepeta cataria L.), were analysed by reversed‐phase HPLC coupled with UV and MS detection. Two major nepetalactones, Z,E‐nepetalactone and E,Z‐nepetalactone, were successfully identified and quantified. The linearity range for Z,E‐nepetalactone was determined as 0.00655–0.655 mg/mL with a correlation coefficient of 0.9999, and the linearity range of E,Z‐nepetalactone was found to be 0.00228–0.456 mg/mL with a correlation coefficient of 0.9999, under UV detection at 228 nm. The linearity ranges were from 0.00164 to 0.0328 mg/mL, with a correlation coefficient of 0.9999, for Z,E‐nepetalactone and 0.00114–0.0228 mg/mL, with a correlation coefficient of 0.9999, for E,Z‐nepetalactone by MS detection with selected ion monitoring of ion peak m/z 167. The MS detection was found to be more sensitive than UV detection and this method was validated as simple, reliable and sensitive for catnip nepetalactone analysis. This method can be used for identification and fingerprinting of catnip products. Copyright © 2007 John Wiley & Sons, Ltd.
Identification of kinetic models for the assessment of reaction hazards
Authors: Kossoy A. , Akhmetshin Yu 
Published: February 2007

AbstractThe assessment, control, and mitigation of reaction hazards is primarily based on the use of kinetic models. These kinetic models are used for the assessment of reaction hazards, the operation and control of the reactor, the design of emergency relief systems, estimation of the consequences of a reaction runaway, etc. The validity of these assessments depends highly on the validity of the kinetic model employed.Several steps are required to identify a suitable kinetic model. This includes:
Selection of the model type.
Estimation of the model's parameters using available data.
Validation of the model.
This article discusses each of these steps in detail and identifies problems associated with each step. Several practical examples are used to demonstrate these problems.The results show that (1) the results are sensitive to a number of assumptions, (2) mistakes may originate from misinterpretation of the thermal data, and (3) computational methods do exist to provide suitable kinetic models for hazard assessment.The analysis employed assumes a batch‐reaction system, since most of the kinetic data available is derived from batch calorimetric equipment. © 2007 American Institute of Chemical Engineers Process Saf Prog, 2007
On Wilson's theory of the collection of charge by falling drops
Authors: Whipple F. J. W. , Chalmers J. A. 
Published: February 2007

AbstractWilson's theory of the acquisition of charges by drops falling through a region containing ions is worked out in detail; diagrams of the paths of ions and curves of the rates of acquisition of charge are drawn. The applications of the theory to the building up of fields in clouds and to the charging of raindrops are briefly discussed.
Mean upper contour patterns of the northern hemisphere — the thermal‐synoptic view‐point
Authors: Sutcliffe R. C. 
Published: February 2007

AbstractThe mean 500 mb contour patterns and 1,000‐500 mb thickness patterns for the northern hemisphere in January and July are examined. The orographic‐dynamical hypothesis advocated by Bolin (1950) is considered. A thermal‐synoptic explanation, resting mainly on the direct thermal effects of land and sea modified by baroclinic synoptic processes, is regarded as satisfactory.
Bubble theory of penetrative convection
Authors: Scorer R. S. , Ludlam F. H. 
Published: February 2007

AbstractThe process of convection is described in terms of a unit or proton of convection ‐ the bubble. A rising bubble of warm air sheds its outer skin steadily into a disturbed wake until it becomes exhausted completely or spreads out at a stable layer. The wake is a region where the ascent of further bubbles is favoured. The wakes of small bubbles close to the ground are aggregated into larger bubbles, which are more dilute, up to a level where they begin to penetrate hitherto undisturbed air, and then they waste away as they ascend further.The air above a bubble is lifted (and cooled) as the bubble approaches and then drains down the outside, the air close to the bubble being mixed into the wake. The wake of a clear bubble is buoyant but that of a cloudy bubble may sink if it is sufficiently chilled by dilution with surrounding clear air.The drag on a bubble is estimated from observations on rising cumulus towers, and a linear relation between buoyancy and limiting velocity is proposed. From this the horizontal velocity of the bubble relative to the surrounding air is deduced to be about the same as the vertical velocity when it ascends through strong shear.A bubble is a compact stable configuration for a rising element. Near the ground the heat is transported by small bubbles, which are less efficient, and therefore require a greater lapse rate, than the larger ones which can operate higher up. The process of aggregation is again renewed within large clouds so that the bubbles found at the top may be more dilute than if they had ascended directly from the base. Clouds growing in a shearing current will grow into the shear.
The growth of ice crystals in a supercooled water cloud
Authors: Mason B. J. 
Published: February 2007

AbstractEquations are derived for the growth rate of ice crystals in the form of thin plates and prismatic columns suspended in a supercooled water cloud of given temperature. The effect of the fall motion of the crystal on its development is discussed ‐ in particular a criterion is derived for the transition from polyhedral to dendritic growth. Ice crystals grown in supercooled water clouds produced in large cold chambers reveal a double change of habit in the temperature range 0°C to −40°C. Experimental determinations of the growth rates of plate crystals growing at −2.5°C and prisms at −5°C are in fairly good agreement with the theory.