bluuebunny/crossref_metadata_2025 huggingface dataset:
Porphyrin‐Appended Europium(III) Bis(phthalocyaninato) Complexes: Synthesis, Characterization, and Photophysical Properties
Authors: Bian Yongzhong , Chen Xinghai , Wang Dongying , Choi Chi‐Fung , Zhou Yang , Zhu Peihua , Ng Dennis K. P. , Jiang Jianzhuang , Weng Yuxiang , Li Xiyou
Published: February 2007

Mixed cyclization of 3‐mono‐, 4‐mono‐, or 4,5‐di(porphyrinated) phthalonitrile compounds2,3, or6and unsubstituted phthalonitrile with the half‐sandwich complex [EuIII(acac)(Pc)] (Pc=phthalocyaninate, acac=acetylacetonate) as the template in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) inn‐pentanol afforded novel porphyrin‐appended europium(III) bis(phthalocyaninato) complexes7–9in 30–40 % yield. These mixed tetrapyrrole triads and tetrad were spectroscopically and electrochemically characterized and their photophysical properties were also investigated with steady‐state and transient spectroscopic methods. It has been found that the fluorescence of the porphyrin moiety is quenched effectively by the double‐decker unit through an intramolecular photoinduced electron‐transfer process, which takes place in several hundred femtoseconds, while the recombination of the charge‐separated state occurs in several picoseconds. By using different phthalocyanines containing different numbers of porphyrin substituents at the peripheral or nonperipheral position(s) of the ligand, while the other unsubstituted phthalocyanine remains unchanged in these double‐deckers, the effects of the number and the position of the porphyrin substituents on these photophysical processes were also examined.
A new temperature‐sensitive contrast mechanism for MRI: Curie temperature transition‐based imaging
Authors: Settecase F. , Sussman M. S. , Roberts T. P. L.
Published: February 2007

A temperature‐sensitive MRI contrast mechanism is proposed based on the physical property, the Curie temperature (Tc), at which a ferromagnetic material transitions to paramagnetic state and vice versa. To evaluate the feasibility of this new contrast mechanism, experiments were performed with solid gadolinium metal, which has a Tc of 20°C. In phantom and ex vivo experiments, the magnetic susceptibility artifact area decreased with increasing temperature transitioning across Tc (p < 0.05). Similar results would be expected for a variety of ferromagnetic substances with substance‐specific Tc values. Temperature‐sensitive MRI contrast agents harnessing this mechanism may be used to (1) indicate regional attainment of specific temperatures in thermotherapy, (2) render an accumulated contrast agent more or less visible by the external application of appropriate heating or cooling, or (3) quantify tissue temperature based on MR image characteristics and magnetic susceptibility artifact caused by a ferromagnetic–paramagnetic transitioning substance. Copyright © 2007 John Wiley & Sons, Ltd.
ASOM applied to column stability
Authors: Ranjbaran A. , Hashemi S.
Published: February 2007

A new method for computation of buckling load and mode shape of a non‐uniform column is proposed. Based on the principles of calculus of variations the stability analysis of the column is defined as an optimization problem. Different known techniques of optimization are candidates for solution process. Through analysis of typical columns and comparison of the results with those of other methods, the basic theory and implementation of the presented method is verified. Copyright © 2007 John Wiley & Sons, Ltd.
Isoform‐specific interaction of Flamingo/Starry Night with excess Bazooka affects planar cell polarity in the Drosophila wing
Authors: Wasserscheid Isabel , Thomas Ulrich , Knust Elisabeth
Published: February 2007

Epithelia display two types of polarity, apical–basal and planar cell polarity (PCP), and both are crucial for morphogenesis and organogenesis. PCP signaling pathways comprise transmembrane proteins, such as Flamingo/Starry Night, and cytoplasmic, membrane‐associated proteins such as Dishevelled. During establishment of PCP in the Drosophila wing, PCP proteins accumulate apically in distinct “cortical domains” on proximal and distal plasma membranes. This finding suggests that their localized function depends on prior definition of apicobasal polarity. Here, we show that overexpression of Bazooka, a PDZ‐domain protein essential for apicobasal polarity in the embryo, perturbs development of PCP, but has no effect on apicobasal polarity. The PCP phenotype is associated with a failure to restrict Flamingo/Starry night to the proximal and distal plasma membranes of the wing epithelium. We further demonstrate that flamingo expresses two differentially spliced RNAs in wing imaginal discs, which encode two isoforms of the atypical cadherin Flamingo. The predominant Starry night–type form contains a PDZ‐binding motif, which mediates binding to Bazooka in vitro. Pull‐down assays support the occurrence of such an interaction in wing imaginal discs. The results suggest that interaction between the apicobasal and planar cell polarity systems has to be tightly coordinated to ensure proper morphogenesis of the wing disc epithelium. Developmental Dynamics 236:1064–1071, 2007. © 2007 Wiley‐Liss, Inc.
Reactions of Group 13 Organometallics tBu3M with Distibanes Sb2R4 (Eur. J. Inorg. Chem. 7/2007)
Authors: Schuchmann Daniella , Kuczkowski Andreas , Fahrenholz Sonja , Schulz Stephan , Flörke Ulrich
Published: February 2007

The cover picture shows the photograph of Robert Bunsen and the statue of Jöns Jakob Berzelius in the centre of Berzeli Park (Stockholm). Both famous chemists investigated the chemistry of tetramethyldiarsane As2Me4 (kakodyl), one of the first organometallic compounds that were initially prepared by Claude‐Louis Cadet de Gassicourt (Cadet's fuming liquid) in 1757. Distibanes Sb2R4, the heavier congeners of diarsanes, exhibit much weaker metal–metal bonds and can be used for interesting bond‐making and bond‐breaking reactions with group 13 organometallic compounds. Details are discussed in the article by S. Schulz et al. on p. 931 ff. The artwork was designed by Dr. Edgar Luttmann.
Cover Picture: Polyazaacenes – On the Way to Stable, Fluorescent and Redox‐Active Derivatives (Eur. J. Org. Chem. 8/2007)
Authors: Stöckner Frances , Beckert Rainer , Gleich Dieter , Birckner Eckhard , Günther Wolfgang , Görls Helmar , Vaughan Gavin
Published: February 2007

The cover picture shows the dyotropic rearrangement of 1,4,5,8‐tetraazafulvalenes into pyrazino‐[2,3‐b]pyrazines. In the case of Ar = 4‐tert‐butylphenyl, the products were immediately transformed, in the presence of oxygen, into derivatives of octaazahexacene through a cascade reaction. These highly ring‐fused compounds display a strong red fluorescence in solution and, in addition, can easily be reduced reversibly. In contact with air, the yellow fluorescent leuco compound formed quickly reoxidized, which is visible by red fluorescent streaks. Details are discussed in the article by R. Beckert et al. on p. 1237 ff.
Computer‐assisted identification of multitrace electrophoretic patterns in differential display experiments
Authors: Vähämaa Heidi , Ojala Pekka , Pahikkala Tapio , Nevalainen Olli S. , Lahesmaa Riitta , Aittokallio Tero
Published: February 2007

Modern multicapillary devices allow researchers to address increasingly complex biological questions involving comparisons of gene expression patterns across electrophoretic samples under various experimental conditions. As labor‐intensive visual evaluation of the electrophoretic results is often the bottleneck of large‐scale differential display (DD) studies, one way to further streamline this process is to focus only on a highly compressed list of the most potential patterns that are likely to provide reliable findings. To enable the identification of such candidate patterns, we present a computer‐assisted method for objective ranking of multitrace peak patterns in DD experiments. The fundamental component of the multitrace pattern ranking method (MRANK) is the multiple alignment algorithm that allows for discovery of patterns involving sets of peak complexes from various electrophoretic samples. A score value is attached to each detected pattern which characterizes how accurately the pattern resembles the desired pattern query, freely defined by the researcher. The ranked pattern list produced by MRANK is validated against visual evaluation in terms of detecting and ranking a group of relevant patterns in a DD analysis of T‐helper cell differentiation. We demonstrate high enrichment of the desired patterns on top of the score‐ranked list (e.g., 90% of the visually selected patterns are discovered by looking through the first 3% of patterns in the ranked list of all patterns). The results suggest that a substantial amount of manual labor can be saved without compromising the accuracy of the findings by prioritizing the patterns according to MRANK output in the visual confirmation phase.
Enantioseparation by CE with vancomycin as chiral selector: Improving the separation performance by dynamic coating of the capillary with poly(dimethylacrylamide)
Authors: Wang Zhaoyan , Wang Junfeng , Hu Zhide , Kang Jingwu
Published: February 2007

An approach for improving the separation performance of the enantioseparation by CE with vancomycin as chiral selector is described. In the present method, a solution of poly(dimethylacrylamide) (PDMA) was used for dynamic coating of the capillary wall to minimize the adsorption of vancomycin onto the capillary wall, and to depress the EOF. Compared with the bare fused‐silica capillaries and the capillaries coated with the polycationic polymer hexadimethrine bromide (HDB), the PDMA‐coated capillary displayed the best separation performance. The resulting coating could withstand hundreds of runs without losing its function. Moreover, a partial filling technique was applied to avoid interference in detection caused by the presence of vancomycin in the buffer. The separation time was shortened when a short‐end‐injection technique was applied. Several parameters such as buffer pH, vancomycin concentration and plug length of the vancomycin solution for the separation were optimized. Under the optimal conditions, all tested enantiomers, including FMOC amino acids derivatives, ketoprofen and fenoprofen, were baseline‐separated in less than 4.2 min.
Analysis of electrokinetic transport of a spherical particle in a microchannel
Authors: Unni Harikrishnan N. , Keh Huan J. , Yang Chun
Published: February 2007

Electrokinetically driven microfluidic devices that are used for biological cell/particle manipulation (e.g., cell sorting, separation) involve electrokinetic transport of these particles in microchannels whose dimension is comparable with particles' size. This paper presents an analytical study on electrokinetic transport of a charged spherical particle in a charged parallel‐plate microchannel. Under the thin electric double‐layer assumption, solutions in closed‐form solutions for the particle velocity and disturbed electrical and fluid velocity fields are obtained for plane‐symmetric (along the channel centerline) and asymmetric (off the channel centerline) motions of a sphere in a parallel‐plate microchannel. The effects of relative particle size and eccentricity (i.e., off the centerline distance) on a particle's translational and rotational velocities are analyzed.
Ratio estimators in adaptive cluster sampling
Authors: Dryver Arthur L. , Chao Chang‐Tai
Published: February 2007

In most surveys data are collected on many items rather than just the one variable of primary interest. Making the most use of the information collected is a issue of both practical and theoretical interest. Ratio estimates for the population mean or total are often more efficient. Unfortunately, ratio estimation is straightforward with simple random sampling, but this is often not the case when more complicated sampling designs are used, such as adaptive cluster sampling. A serious concern with ratio estimates introduced with many complicated designs is lack of independence, a necessary assumption. In this article, we propose two new ratio estimators under adaptive cluster sampling, one of which is unbiased for adaptive cluster sampling designs. The efficiencies of the new estimators to existing unbiased estimators, which do not utilize the auxiliary information, for adaptive cluster sampling and the conventional ratio estimation under simple random sampling without replacement are compared in this article. Related result shows the proposed estimators can be considered as a robust alternative of the conventional ratio estimator, especially when the correlation between the variable of interest and the auxiliary variable is not high enough for the conventional ratio estimator to have satisfactory performance. Copyright © 2007 John Wiley & Sons, Ltd.
GIS‐assisted modelling for debris flow hazard assessment based on the events of May 1998 in the area of Sarno, Southern Italy: Part I. Maximum run‐out
Authors: Toyos G. , Dorta D. Oramas , Oppenheimer C. , Pareschi M. T. , Sulpizio R. , Zanchetta G.
Published: February 2007

Based on the debris flow events that occurred in May 1998 in the area of Sarno, Southern Italy, this paper presents an approach to simulate debris flow maximum run‐out. On the basis of the flow source areas and an average thickness of 1·2 m of the scarps, we estimated debris flow volumes of the order of 104 and 105 m3. Flow mobility ratios (ΔH/L) derived from the x, y, z coordinates of the lower‐most limit of the source areas (i.e. apex of the alluvial fan) and the distal limit of the flows ranged between 0·27 and 0·09. We performed regression analyses that showed a good correlation between the estimated flow volumes and mobility ratios. This paper presents a methodology for predicting maximum run‐out of future debris flow events, based on the developed empirical relationship. We implemented the equation that resulted from the calibration as a set of GIS macros written in Visual Basic for Applications (VBA) and running within ArcGIS. We carried out sensitivity analyses and observed that hazard mapping with this methodology should attempt to delineate hazard zones with a minimum horizontal resolution of 0·4 km. The developed procedure enables the rapid delineation of debris flow maximum extent within reasonable levels of uncertainty, it incorporates sensitivities and it facilitates hazard assessments via graphic user interfaces and with modest computing resources. Copyright © 2007 John Wiley & Sons, Ltd.
Thymus piperella (L.) essential oil: an alternative in the treatment of diarrhoea
Authors: Martí D. , Pérez‐Gracia MT , Blanquer A. , Villagrasa V. , Sanahuja M.A. , Moreno L.
Published: February 2007

Thymus piperella (L.) (family Labiatae) is an endemic taxon found in eastern Spain. The aerial part of T. piperella is principally used for culinary purposes, to flavour stuffings, sauces, pickles, stews, soups, etc. Moreover, it has traditionally been used to conserve and soften olives, and in the distillation of an alcoholic beverage named ‘herbero’, which is typical in the south of Valencia and north of Alicante, and whose digestive properties are well documented. Despite it being a popular plant in this region, to date T. piperella (L.) has not been pharmacologically described. Pharmacological assays have been carried out on the essential oil of Thymus piperella (L.) leaves. The oil was shown to be innocuous according to the acute oral toxicity test and exhibited antispasmodic action that significantly inhibited the contractions induced by acetylcholine in the isolated rat ileum in a concentration‐dependent manner. Essential oil from Thymus piperella (L.) leaves was active against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus pyogenes and Mycobacterium phlei. Such antimicrobial activity would explain the popular use of this plant in the conservation of olives. Moreover, as the inhibition of contractile overactivity of the ileum (antispasmodic action) is the basis of the treatment of some gastrointestinal disorders, such as diarrhoea, and as many diarrhoea‐causing diseases are associated with intestinal infection, Thymus piperella essential oil could constitute an alternative therapy in such cases. In this way, this species, so commonly used in the Mediterranean kitchen, may be beneficial to the health in more ways than one. Copyright © 2007 John Wiley & Sons, Ltd.
Coexistence of Sexual and Parthenogenetic Artemia Populations in Lake Urmia and Neighbouring Lagoons
Authors: Agh Naser , Abatzopoulos Theodore J. , Kappas Ilias , Van Stappen Gilbert , Razavi Rouhani Seyed M. , Sorgeloos Patrick
Published: February 2007

We studied the Artemia populations existing in Lake Urmia (north‐western Iran), one of the largest habitats of Artemia in the world, in order to settle the long‐standing controversy over the sexual status of the endemic Artemia populations. Experiments were carried out in the laboratory and in the field. Cysts, collected from different sites of the lake and peripheral lagoons, were hatched and cultured to adults in the laboratory. Adult sexual and parthenogenetic animals were isolated and newly hatched nauplii from them were cultured to maturity in different salinities, ranging from 15–80 ppt. Survival levels and percentage of animals attaining adulthood were measured over a period of 30 days. In the field experiment, cysts taken from Lake Urmia were hatched and the resulting nauplii were inoculated into six earthen ponds (80–140 ppt) constructed in the vicinity of the lake. Population composition in each pond was determined over a period of two years. Results indicated that both sexual and parthenogenetic Artemia coexist in Lake Urmia. While the lake itself is dominated by sexual Artemia, the asexual populations were found to be restricted to particular areas in or near the lake. Artemia appearing seasonally in the lagoons adjacent to the lake were exclusively parthenogenetic. Parthenogens could grow, mature and reproduce at very low salinities (15–33 ppt), whereas higher salinities (above 50 ppt) were required for A. urmiana to attain sexual maturity. We consider salinity to be a major abiotic factor determining the distribution of these sexually different populations within and outside the lake. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exposure to mixtures of endosulfan and zineb induces apoptotic and necrotic cell death in SH‐SY5Y neuroblastoma cells,in vitro
Authors: Jia Zhenquan , Misra Hara P.
Published: February 2007

A number of epidemiological studies have demonstrated a strong association between the incidence of Parkinson's disease and pesticide exposure. Earlier it was demonstrated that exposure to the pesticides endosulfan and zineb, alone and in combination, caused neurodegenerationin vivo. It was hypothesized that these pesticides cause neurotoxicity, in part, by enhancing apoptotic cell death. SH‐SY5Y human neuroblastoma cells, which retain a catecholaminergic phenotype, were exposed to endosulfan, zineb or a combination of these chemicals,in vitro. For mixture studies, concentrations of pesticides (100 µmeach) were chosen based on LC25(lethal concentration) that would result in minimum cell death. Exposure to a mixture of pesticides exhibited significantly (P≤ 0.05) higher toxicity than each one alone. Both pesticides were found to cause apoptotic cell death that was concentration (50–400 µm) dependent. A flow cytometric (7‐aminoactinomycin D) assay was used to distinguish live, early apoptotic and late apoptotic/necrotic populations. Exposure to mixtures of the pesticides enhanced both early apoptosis and late apoptosis/necrosis compared with either chemical alone. Visual evaluation using a DNA ladder assay and a fluorescence Annexin V/PI assay confirmed the contribution of both apoptotic and necrotic processes. These findings suggest that the cytotoxicity of endosulfan and zineb, both individually and in mixtures, is associated with the occurrence of early and late apoptotic/necrotic processes in SH‐SY5Y human neuroblastoma cells and support the contention that pesticide‐induced neuronal cell death leading to neurodegenerative disease may, at least in part, be associated with early and late apoptosis of dopaminergic neurons. Copyright © 2007 John Wiley & Sons, Ltd.
Entry of two new asymmetric bispyridinium oximes (K‐27 and K‐48) into the rat brain: comparison with obidoxime
Authors: Lorke D. E. , Hasan M. Y. , Nurulain S. M. , Sheen R. , Kuča K. , Petroianu G. A.
Published: February 2007

In the search for new oximes with higher reactivation potency and a broader spectrum, K‐27 and K‐48, have recently been synthesized. To test if their superior efficacy was related to better penetration across the blood–brain barrier, their brain entry was compared with that of obidoxime, when administered either alone or after the organophosphate paraoxon (POX). Rats received 50 µmol obidoxime, K‐27 or K‐48, either alone or in addition to 1 µmol POX. Oxime concentrations at various points in time in brain and plasma were measured using HPLC.

The obidoxime Cmax in brain was 1.3% of the plasma Cmax when injected alone, and 1.5% when injected following POX. The ratio of the area under the curve (AUC) brain to plasma for obidoxime was around 6%, irrespective of whether it was administered alone or after POX. For K‐27, Cmax (brain) was 0.6% of Cmax (plasma) when injected alone, and 0.7% when injected after POX (no significant difference). The AUC (brain) was 2% of AUC (plasma) for both K‐27 groups. K‐48, when injected alone reached 1.4% of Cmax (plasma) in the brain and 1.2% of Cmax (plasma), when injected following POX. The AUC (brain) was 5% of the AUC (plasma), both when K‐48 was administered alone and in combination with POX.

Entry of all three oximes into the brain is minimal and cannot explain the better therapeutic efficacy of K‐27 and K‐48. As already observed for pralidoxime, injection of POX before oxime administration had no influence upon penetration across the blood–brain barrier. Copyright © 2007 John Wiley & Sons, Ltd.
Hill‐climbing to Pasch valleys
Authors: Heap Danny , Danziger Peter , Mendelsohn Eric
Published: February 2007

Exhaustive enumeration of Steiner Triple Systems is not feasible, due to the combinatorial explosion of instances. The next‐best hope is to quickly find a sample that is representative of isomorphism classes. Stinson's Hill‐Climbing algorithm [20] is widely used to produce random Steiner Triple Systems, and certainly finds a sample of systems quickly, but the sample is not uniformly distributed with respect to the isomorphism classes of STS with ν ≤ 19, and, in particular, we find that isomorphism classes with a large number of Pasch configurations are under‐represented. No analysis of the non‐uniformity of the distribution with respect to isomorphism classes or the intractability of obtaining a representative sample for ν > 19 is known. We also exhibit a modification to hill‐climbing that makes the sample if finds closer to the uniform distribution over isomorphism classes in return for a modest increase in running time. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 405–419, 2007
Ascorbate transport by primary cultured neurons and its role in neuronal function and protection against excitotoxicity
Authors: Qiu Shenfeng , Li Liying , Weeber Edwin J. , May James M.
Published: February 2007

Neurons maintain relatively high intracellular concentrations of ascorbic acid, which is achieved primarily by the activity of the sodium‐dependent vitamin C transporter SVCT2. In this work, we studied the mechanisms by which neuronal cells in culture transport and maintain ascorbate as well as whether this system contributes to maturation of neuronal function and cellular defense against oxidative stress and excitotoxic injury. We found that the SVCT2 helps to maintain high intracellular ascorbate levels, normal ascorbate transport kinetics, and activity‐dependent ascorbate recycling. Immunocytochemistry studies revealed that SVCT2 is expressed primarily in the axons of mature hippocampal neurons in culture. In the absence of SVCT2, hippocampal neurons exhibited stunted neurite outgrowth, less glutamate receptor clustering, and reduced spontaneous neuronal activity. Finally, hippocampal cultures from SVCT2‐deficient mice showed increased susceptibility to oxidative damage and N‐methyl‐D‐aspartate‐induced excitotoxicity. Our results revealed that maintenance of intracellular ascorbate as a result of SVCT2 activity is crucial for neuronal development, functional maturation, and antioxidant responses. © 2007 Wiley‐Liss, Inc.
The influence of a pulsating electric field on selenium accumulation in Kluyveromyces marxianus cells
Authors: Pankiewicz Urszula , Jamroz Jerzy
Published: February 2007

K. marxianus was cultivated under conditions of PEF (pulse electric field) action and a selenium source. The culture duration after which cells were treated with PEF, the field exposure time and the selenium concentration in the medium were all optimized. Optimization of culture duration caused a 33% increase in selenium accumulation in cells as compared to the control with no PEF treatment. The highest selenium accumulation – about 167 μg/g dry mass (DM) – was recorded after 3‐minute PEF treatment of 16‐hour culture. A roughly two‐fold increase in selenium content was achieved after optimization of culture duration and PEF treatment time. Finding the optimum selenium concentration in the medium brought about a 13‐fold increase of selenium accumulation in the cells of K. marxianus. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production of L(+) lactic acid from cassava starch hydrolyzate by immobilized Lactobacillus delbrueckii
Authors: John Rojan Pappy , Nampoothiri Kesavan Madhavan , Pandey Ashok
Published: February 2007

A process based on low cost production media was developed for fermentative production of L(+) lactic acid. Various process parameters were optimized for the production of L(+) lactic acid from cassava starch hydrolyzate‐based medium by immobilized whole cells of Lactobacillus delbrueckii. The parameters considered for optimization were concentration of alginate and CaCl2, initial cell concentration, curing time, bead size and incubation time of fermentation. Reusability of immobilized cells up to six batches was observed without any decline in lactate production. Lactate yield for L. delbrueckii was 0.93 g lactic acid × g–1 reducing sugar with a production rate of 0.33 g × l–1 × h–1. A column bioreactor packed with immobilized L. delbrueckii was run for three weeks in a continuous mode with a lactate yield of 0.75–0.95 g lactic acid × g–1 reducing sugar with an average production rate of 0.48 g × l–1 × h–1. The study revealed that agro residues like cassava bagasse could be used as source material for developing a low cost technology for lactate production. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Compact 0.56 Petawatt laser system based on optical parametric chirped pulse amplification in KD*P crystals
Authors: Lozhkarev V V , Freidman G I , Ginzburg V N , Katin E V , Khazanov E A , Kirsanov A V , Luchinin G A , Mal'shakov A N , Martyanov M A , Palashov O V , Poteomkin A K , Sergeev A M , Shaykin A A , Yakovlev I V
Published: February 2007

560 TW peak power has been achieved experimentally using a Cr:forsterite master oscillator at 1250 nm, a stretcher, three optical parametrical amplifiers based on KD*P crystals providing 38 J energy in the chirped pulse at 910 nm central wavelength, and a vacuum compressor providing 43 fs pulse duration. To our knowledge, it is a world-record OPCPA system and one of the five most powerful laser systems currently available.
Experimental determination of threshold dose in photodynamic therapy in normal rat liver
Authors: Ferreira J , Moriyama L T , Kurachi C , Sibata C , Castro e Silva Jr. O , Zucoloto S , Bagnato V S
Published: February 2007

Using normal rat liver we investigated the depth of necrosis induced by photodynamic therapy when different light doses and photosensitizer (Photogem®) concentrations. All experiments were done with a fluence rate of 250 mW/cm2. Photosensitizer concentration was varied from 1.0, 1.5, 2.0, and 5.0 mg/kg of body weight and it was administered through the left tail vein. For each photosensitizer concentration the light dose was varied from 10, 50, 100, 150, and 200 J/cm2. Each experimental point was done using five animals. The depth of necrosis analysis allows us to determine the threshold dose and compare its value with the existent results in the literature. Our result suggested a value about 3 times higher than the conventionally adopted value. It indicates the dependence of such value with the employed concentration photosensitizer.

The use of simple models to understand basic features of the PDT (Photodynamic Therapy) may contribute to the solid establishment of dosimetry in PDT enhancing its use in the clinical management of cancers and others lesions.
Bladder inhibition or voiding induced by pudendal nerve stimulation in chronic spinal cord injured cats
Authors: Tai Changfeng , Wang Jicheng , Wang Xianchun , de Groat William C. , Roppolo James R.
Published: February 2007

Aims

To investigate pudendal‐to‐bladder spinal reflexes in chronic spinal cord injured (SCI) cats induced by electrical stimulation of the pudendal nerve.

Methods

Bladder inhibition or voiding induced by pudendal nerve stimulation at different frequencies (3 or 20 Hz) was studied in three female, chronic SCI cats under α‐chloralose anesthesia.

Results

Voiding induced by a slow infusion (2–4 ml/min) of saline into the bladder was very inefficient (voiding efficiency = 7.3% ± 0.9%). Pudendal nerve stimulation at 3 Hz applied during the slow infusion inhibited reflex bladder activity, and significantly increased bladder capacity to 147.2 ± 6.1% of its control capacity. When the 3‐Hz stimulation was terminated, voiding rapidly occurred and the voiding efficiency was increased to 25.4 ± 6.1%, but residual bladder volume was not reduced. Pudendal nerve stimulation at 20 Hz induced large bladder contractions, but failed to induce voiding during the stimulation due to the direct activation of the motor pathway to the external urethral sphincter. However, intermittent pudendal nerve stimulation at 20 Hz induced post‐stimulus voiding with 78.3 ± 12.1% voiding efficiency. The voiding pressures (39.3 ± 6.2 cmH2O) induced by the intermittent pudendal nerve stimulation were higher than the voiding pressures (23.1 ± 1.7 cmH2O) induced by bladder distension. The flow rate during post‐stimulus voiding induced by the intermittent pudendal nerve stimulation was significantly higher (0.93 ± 0.04 ml/sec) than during voiding induced by bladder distension (0.23 ± 0.07 ml/sec).

Conclusions

This study indicates that a neural prosthetic device based on pudendal nerve stimulation might be developed to restore micturition function for people with SCI. Neurourol. Urodynam. 26:570–577, 2007. © 2007 Wiley‐Liss, Inc.
Magnetization transfer effects on the efficiency of flow‐driven adiabatic fast passage inversion of arterial blood
Authors: Hernandez‐Garcia Luis , Lewis David P. , Moffat Bradford , Branch Craig A.
Published: February 2007

Continuous arterial spin labeling experiments typically use flow‐driven adiabatic fast passage inversion of the arterial blood water protons. In this article, we measure the effect of magnetization transfer in blood and how it affects the inversion label. We use modified Bloch equations to model flow‐driven adiabatic inversion in the presence of magnetization transfer in blood flowing at velocities from 1 to 30 cm/s in order to explain our findings. Magnetization transfer results in a reduction of the inversion efficiency at the inversion plane of up to 3.65% in the range of velocities examined, as well as faster relaxation of the arterial label in continuous labeling experiments. The two effects combined can result in inversion efficiency reduction of up to 8.91% in the simulated range of velocities. These effects are strongly dependent on the velocity of the flowing blood, with 10 cm/s yielding the largest loss in efficiency due to magnetization transfer effects. Flowing blood phantom experiments confirmed faster relaxation of the inversion label than that predicted by T1 decay alone. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of the new silane‐based antioxidant containing 2,6‐di‐tert‐butylphenolic stabilizing moiety
Authors: Nedelčev T. , Krupa I. , Csomorová K. , Janigová I. , Rychlý J.
Published: February 2007

A new kind of antioxidant 4‐[(3‐(triethoxysilyl)propylimino)methyl]‐2,6‐di‐tert‐butylphenol consisting of an alkoxysilyl group and a 2,6‐di‐tert‐butylphenol stabilizing moiety was synthesized and tested in isotactic poly(propylene). FT‐IR, 1H‐NMR, 13C‐NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) were used for characterization of synthesized silane stabilizer. The derivative of 4‐[(3‐(triethoxysilyl)propylimino)methyl]‐2,6‐di‐tert‐butylphenol was also prepared by the condensation reaction using the sol‐gel process. Stabilizing activity of the new silane stabilizer and its condensed form was verified by chemiluminiscence and thermogravimetry measurements in oxygen atmosphere and compared with conventional 2,6‐di‐tert‐butyl‐4‐methyl‐ phenol as well as with the conventional stabilizing system based on the mixture of Irganox 1010/Irgafos168 (weight ratio of 1:2). Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of new polyfluorene copolymers with a comonomer containing triphenylamine units and their applications in white‐light‐emitting diodes
Authors: Lee Sang Kyu , Ahn Taek , Cho Nam Sung , Lee Jeong‐Ik , Jung Young Kwan , Lee Jonghee , Shim Hong Ku
Published: February 2007

Novel conjugated polyfluorene copolymers, poly[9,9‐dihexylfluorene‐2,7‐diyl‐co‐(2,5‐bis(4′‐diphenylaminostyryl)‐phenylene‐1,4‐diyl)]s (PGs), have been synthesized by nickel(0)‐mediated polymerization from 2,7‐dibromo‐9,9‐dihexylfluorene and 1,4′‐dibromo‐2,5‐bis(4‐diphenylaminostyryl)benzene with various molar ratios of the monomers. Because of the incorporation of triphenylamine (TPA) moieties, PGs exhibit much higher HOMO levels than the corresponding polyfluorene homopolymers and are able to facilitate hole injection into the polymer layer from the anode electrode in light‐emitting diodes. Conventional polymeric light‐emitting devices with the configuration ITO/PEDOT:PSS/polymer/Ca/Al have been fabricated. A light‐emitting device produced with one of the PG copolymers (PG10) as the emitting layer exhibited a voltage‐independent and stable bluish‐green emission with color coordinates of (0.22, 0.42) at 5 V. The maximum brightness and current efficiency of the PG10 device were 3370 cd/m2 (at 9.6 V) and 0.6 cd/A, respectively. To realize a white polymeric light‐emitting diode, PG10 as the host material was blended with 1.0 wt % of a red‐light‐emitting polymer, poly[9,9‐dioctylfluorene‐2,7‐diyl‐alt‐2,5‐bis(2‐thienyl‐2‐cyanovinyl)‐1‐(2′‐ethylhexyloxy)‐4‐methoxybenzene‐5′,5′‐diyl] (PFR4‐S), and poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV). The device based on PG10:PFR4‐S showed an almost perfect pure white electroluminescence emission, with Commission Internationale de l'Eclairage (CIE) coordinates of (0.33, 0.36) at 8 V; for the PG10:MEH‐PPV device, the CIE coordinates at this voltage were (0.30, 0.40) with a maximum brightness of 1930 cd/m2. Moreover, the white‐light emission from the PG10:PFR4‐S device was stable even at different driving voltages and had CIE coordinates of (0.34, 0.36) at 6 V and (0.31, 0.35) at 10 V. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1199–1209, 2007
The role of CH/π interaction in the stabilization of less‐soluble diastereomeric salt crystals
Authors: Saigo Kazuhiko , Kobayashi Yuka
Published: February 2007

Enantiopure 2‐naphthylglycolic acid (NGA) and cis‐1‐aminobenz[f]indan‐2‐ol (ABI) were rationally designed as new resolving agents on the model of mandelic acid (MA) and cis‐1‐aminoindan‐2‐ol (AI), respectively. As expected, NGA and ABI showed superior chiral recognition ability to racemates, compared with MA and AI. In order to clarify any factors governing the chiral recognition abilities of NGA and ABI, the crystal structures of their less‐ and more‐soluble diastereomeric salts were determined by X‐ray crystallographic analyses and revealed that CH/π interactions play an intrinsic role in chiral recognitions. A theoretical investigation was also performed with the periodic ab initio method by using the X‐ray crystal structures of the less‐soluble salt crystals with AI and ABI to find the unique properties of CH/π interaction in the crystalline state, which largely contributed to the stabilization of the crystals. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 47–56; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20100
Significance of Laparoscopic Splenectomy in Patients with Hypersplenism
Authors: Watanabe Yuji , Horiuchi Atsushi , Yoshida Motohira , Yamamoto Yuji , Sugishita Hiroki , Kumagi Teru , Hiasa Yoichi , Kawachi Kanji
Published: February 2007

Objective

This study was aimed at investigating the efficacy and safety of minimally invasive laparoscopic splenectomy in patients with hypersplenism secondary to cirrhosis.

Background

While advances have been made in the treatment of liver cancer and chronic hepatitis, certain treatments such as radio frequency ablation (RFA) must often be discontinued due to thrombocytopenia caused by hypersplenism. Laparoscopic splenectomy is performed to treat diseases as idiopathic thrombocytopenic purpura, but is contraindicated for hypersplenism in many institutions. Few studies have thus examined the safety and efficacy of this approach.

Methods

Efficacy and safety were retrospectively analyzed for laparoscopic splenectomies starting from January 2003. Relationships between postoperative increases in platelet count and thrombopoietin, platelet‐associated immunoglobulin, excised spleen weight, and serum parameters were examined. Perioperative data of open splenectomies starting from January 1990 were compared with those of laparoscopic splenectomies.

Results

No laparoscopic cases were converted to open surgery in this series. Mean operative times of open and laparoscopic splenectomy were 205 and 173 min respectively. Mean blood losses were 750 and 359 ml (P < 0.05) and the mean weights of excised spleen were 460 and 525 g respectively. Postoperatively, no changes in liver function were noted, and platelet and leukocyte counts were significantly increased. Compared with preoperative platelet count, degree of increase at 2 weeks postoperatively did not correlate with preoperative thrombopoietin levels, but significantly correlated with levels of platelet‐associated immunoglobulin and spleen volume (P < 0.05). Postoperative portal or splenic vein thrombosis (PSVT) was seen in 3 patients and these patients did not exhibit any clinical symptoms.

Conclusions

Laparoscopic splenectomy is a safe technique for the treatment of hypersplenism and contributes to postoperative increases in platelet counts. Postoperative increases in platelet count seem to depend on platelet‐associated immunoglobulin level and spleen weight, which may be valuable prognosticators.
The relationship between self‐reported received and perceived social support: A meta‐analytic review
Authors: Haber Mason G. , Cohen Jay L. , Lucas Todd , Baltes Boris B.
Published: February 2007

Social support is broad term encompassing a variety of constructs, including support perceptions (perceived support) and receipt of supportive behaviors (received support). Of these constructs, only perceived support has been regarded as consistently linked to health, and researchers have offered differing assessments of the strength of the received‐perceived support relationship. An overall estimate of the received‐perceived support relationship would clearly further the dialogue on the relationship between received and perceived support and thus assist in the theoretical development of the field. This study evaluated all available studies using the Inventory of Socially Supportive Behaviors (ISSB; Barrera, Sandler, & Ramsey, 1981, American Journal of Community Psychology, 9, 435–447) and any measure of perceived social support. Using effect sizes from 23 studies, we found an average correlation of r = .35, p < .001. Implications of this estimate for further development of models of social support as well as interventions to enhance social support are discussed.
Impact of diabetes on left ventricular diastolic function in patients with arterial hypertension
Authors: Wachter Rolf , Lüers Claus , Kleta Sibylle , Griebel Kerstin , Herrmann‐Lingen Christoph , Binder Lutz , Janicke Nico , Wetzel Dirk , Kochen Michael M. , Pieske Burkert
Published: February 2007

Aims

To analyse the effect of diabetes (DM) on diastolic function in hypertensive patients.

Methods

439 hypertensive patients were selected for participation in this study. All participants had an echocardiographic evaluation of systolic and diastolic function. The overall degree of diastolic function and specific parameters (e.g. E/Ea ratio) were analysed.

Results

We divided the cohort (63±10 years) into those with diabetes mellitus (DM(+), n=124) and without diabetes mellitus (DM(–), n=315). The prevalence of normal diastolic function was lower in DM(+) than DM(–) (19.4% vs. 30.8%); mild (65.3% vs. 60.0%) and moderate/ severe diastolic dysfunction were more frequent in DM(+) (15.3% vs. 9.2%, p=0.022). The E/Ea ratio, an estimate of left ventricular end‐diastolic pressure, was significantly higher in DM(+) (12.3±4.4) as compared to DM(–) (10.8±3.6, p<0.001). Sex‐specific analysis revealed that the effect of DM on diastolic function was mainly limited to the male subgroup. Multivariate logistic regression analysis showed that diabetes affected diastolic function in males independent of blood pressure, left ventricular mass index, concomitant medication and prevalence of coronary artery disease.

Conclusion

Diabetes negatively affects diastolic function in patients with arterial hypertension. This effect is mainly confined to the male subgroup.
Processes of change in treatment for chronic pain: The contributions of pain, acceptance, and catastrophizing
Authors: Vowles Kevin E. , McCracken Lance M. , Eccleston Christopher
Published: February 2007

Cognitive‐behavioral therapy has a substantial evidence base with regard to its effectiveness for individuals with chronic pain. Historically, although there has been some investigation in to the processes by which treatment succeeds or fails, few data are available regarding the unique contributions of processes from distinct cognitive behavioral approaches and how these processes may interact to affect patient functioning. The present investigation sought to evaluate three proposed process variables that have garnered empirical support within chronic pain settings, namely: pain intensity, catastrophizing, and acceptance. Participants were 252 consecutive patients who completed treatment on an interdisciplinary pain management unit. Using multiple regression, the contributions of changes in process variables to changes in treatment outcomes were assessed. In general, changes in both acceptance and catastrophizing accounted for significant variance independent of, and larger than, that accounted for by change in pain intensity. Changes in acceptance and catastrophizing accounted for roughly equivalent amounts of variance when entered immediately following changes in pain, and when entered following one another. The potential impact of these results is discussed in relation to the particular treatment delivered. Issues relating to change at the level of frequency or content of psychological experiences are considered relative to change in the functions of these experiences.
Mitochondrial uncoupling protein 2 gene transcript levels are elevated in maturating erythroid cells
Authors: Flachs Pavel , Sponarova Jana , Kopecky Pavel , Horvath Ondrej , Sediva Anna , Nibbelink Maryse , Casteilla Louis , Medrikova Dasa , Neckar Jan , Kolar Frantisek , Kopecky Jan
Published: February 2007

Mitochondrial uncoupling protein 2 (UCP2) is abundant in developing monocyte/macrophage cells and may affect hematopoiesis by reducing formation of reactive oxygen species. The aims of this study were to further characterize the involvement of UCP2 in hematopoiesis. In situ hybridization in mouse embryos identified UCP2‐positive cells in liver and inside primitive blood vessels from 10.5 days of prenatal development. High UCP2 transcript levels were detected in reticulocytes and other maturating erythroid cells in peripheral blood of mice exposed to hypoxia, and in umbilical cord blood of human neonates and peripheral blood of adults. Our results suggest involvement of UCP2 in erythropoiesis.
An assessment of changes in properties of steppe kurgan paleosoils in relation to prevailing climates over recent millennia
Authors: Khomutova Tatiana E. , Demkina Tatiana S. , Borisov Alexander V. , Kashirskaya Natalia N. , Yeltsov Maxim V. , Demkin Vitaly A.
Published: February 2007

Comparative analysis of morphological and chemical properties of the soil chronosequence on Kastanozems soils in the steppe zone of the Russian Plain, which included paleosoils buried beneath kurgans erected ca. 2000 BC, AD 50, AD 200, and AD 1250 was performed to reconstruct the paleoenvironmental conditions in this archeologically important region. Paleoenvironmental dynamics were traced using the state of microbial communities of paleo and modern soils (including the dynamics of total and glucose-reactive biomass, and the abundance of microorganisms grown on selected media). We demonstrate that the share of the glucose-reactive microorganisms in the microbial community, the ecological–trophic structure, and oligotrophicity index might serve as indicators of the state of microbial communities and be used for paleoenvironmental reconstructions. The morphological–chemical and microbial properties confirm an arid period ca. 2000 BC, slightly wetter conditions ca. AD 50, and more humid conditions ca. AD 1250.
Convection of a binary fluid saturating a shallow porous cavity subjected to cross heat fluxes
Authors: BAHLOUL A. , VASSEUR P. , ROBILLARD L.
Published: February 2007

In this work, natural convection in a differentially heated binary mixture is studied analytically and numerically. The fluid is subjected to the Soret effect and is contained in a shallow rectangular porous cavity. All four faces are exposed to uniform heat fluxes, opposite faces being heated and cooled, respectively. Analytical solutions for the stream function, temperature and concentration fields are obtained using a parallel flow assumption in the core region of the cavity and an integral form of the energy and constituent equations. Numerical confirmation of the analytical predictions is also obtained. Results are presented first in the presence of a vertical temperature gradient (a = 0) for which the solution takes the form of a standard Bénard bifurcation. For this situation, steady bifurcations are either pitchfork or subcritical, depending on the separation parameter ϕ and Lewis number Le. The imperfection brought by a horizontal temperature gradient (a≠0) to the bifurcation is then investigated. Both the nonlinear analytical model and the numerical solution indicate that, depending on a, ϕ and Le, the onset of motion occurs through subcritical bifurcations. The existence of transcritical bifurcations is also demonstrated. The special case where the buoyancy forces induced by the thermal and solutal forces are opposing and of equal intensity (ϕ =-1) is also discussed. For this particular situation, the supercritical Rayleigh number for the onset of convection is predicted on the basis of a linear stability analysis. Multiple steady states near the threshold of convection are found.