bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin C stability in encapsulated green West Indian cherry juice and in encapsulated synthetic ascorbic acid
Authors: Righetto Andréa Mara , Netto Flavia Maria
Published: May 2006

Kinetic studies on the degradation of vitamin C and nonenzymatic browning of green West Indian cherry juice and synthetic ascorbic acid, encapsulated in maltodextrin DE20 and a mixture of this with gum arabic, were carried out at different temperatures (15, 25, 35 and 45 °C). Vitamin C degradation followed the first‐order and nonenzymatic browning a zero‐order kinetic model. At higher storage temperatures the formulation containing a mixture of maltodextrin and gum arabic (3:1) was the most effective for vitamin C protection. An increase in storage temperature showed a greater impact on the degradation of synthetic vitamin C than on that of the green West Indian cherry juice. These differences could be due to the presence of phenolic compounds with antioxidant activity, protecting the vitamin C. Copyright © 2006 Society of Chemical Industry
Chemical characterization of tomato pomace
Authors: Del Valle Marcos , Cámara Montaña , Torija Maria‐Esperanza
Published: May 2006

Tomato‐processing by‐product, also known as tomato pomace, consists of peel and seeds and represents around 4% of the fruit weight. If these wastes remain unused, they not only add to the disposal problem but also aggravate environmental pollution. The aim of this paper is to evaluate the chemical composition of tomato pomace collected at different steps during industrial processing in order to assess the quality of this by‐product. Twenty‐one tomato pomace samples were considered for analysis. Samples corresponded to different steps during tomato processing for paste: seven after pulper, five after finisher, six before turbopress and three after turbopress. Samples were analyzed for moisture content, total and soluble sugars, protein, fat, soluble and total fiber, as well as mineral content. From the results obtained we can conclude that tomato pomace composition (in dry weight basis) is as follows: 59.03% fiber, 25.73% total sugars, 19.27% protein, 7.55% pectins, 5.85% total fat and 3.92% minerals. Copyright © 2006 Society of Chemical Industry
Mobile‐phase pH influence on the retention of some benzoic acid derivatives in reversed‐phase chromatography
Authors: Karasová Gabriela , Kowalska Sylwia , Lehotay Jozef , Buszewski Boguslaw
Published: May 2006

Five end‐capped octadecyl RP stationary phases, among which one was a polar embedded stationary phase, were tested for the analysis of benzoic acid derivatives using two mobile phases with or without addition of formic acid (water pH was measured by a common approach; pH of water with addition of formic acid was 3.0 and without formic acid 5.8). The influence of mobile‐phase pH on the retention of benzoic acid derivatives was under study. Consequently, Purospher‐STAR and Alltima columns provided symmetrical peaks for benzoic acid derivatives at pH 3.0 and also at pH 5.8. Reprosil and Symmetry stationary phases showed poor peak shapes at higher pH of the mobile phase. Differences between the tested columns may be caused by surface heterogeneity. Another reason may be the presence of some atoms creating additional adsorption sites on the surface of Reprosil and Symmetry stationary phases. This can lead to enhanced silanol activity resulting in peak tailing. The addition of formic acid into the mobile phase improved peak shapes. The polar embedded C18 stationary‐phase Synergi‐Fusion‐RP appeared as not a suitable column for the analysis of benzoic acid derivatives. Synergi‐Fusion‐RP provided asymmetrical peaks even if formic acid was added into the mobile phase.
Comparison of sample preparation methods combined with fast gas chromatography – mass spectrometry for ultratrace analysis of pesticide residues in baby food
Authors: Hercegová Andrea , Dömötörová Milena , Kružlicová Dáša , Matisová Eva
Published: May 2006

Four sample preparation techniques were compared for the ultratrace analysis of pesticide residues in baby food: (a) modified Schenck's method based on ACN extraction with SPE cleaning; (b) quick, easy, cheap, effective, rugged, and safe (QuEChERS) method based on ACN extraction and dispersive SPE; (c) modified QuEChERS method which utilizes column‐based SPE instead of dispersive SPE; and (d) matrix solid phase dispersion (MSPD). The methods were combined with fast gas chromatographic‐mass spectrometric analysis. The effectiveness of clean‐up of the final extract was determined by comparison of the chromatograms obtained. Time consumption, laboriousness, demands on glassware and working place, and consumption of chemicals, especially solvents, increase in the following order QuEChERS < modified QuEChERS < MSPD < modified Schenck's method. All methods offer satisfactory analytical characteristics at the concentration levels of 5, 10, and 100 μg/kg in terms of recoveries and repeatability. Recoveries obtained for the modified QuEChERS method were lower than for the original QuEChERS. In general the best LOQs were obtained for the modified Schenck's method. Modified QuEChERS method provides 21–72% better LOQs than the original method.
Soil degradation processes and plant colonization in abandoned terraced fields overlying pumice tuffs
Authors: Arbelo C. D. , Rodríguez‐Rodríguez A. , Guerra J. A. , Mora J. L. , Notario J. S. , Fuentes F.
Published: May 2006

The state of soil degradation/regeneration in abandoned agricultural terraced fields over pumiceous tuffs has been assessed in this paper. In an initial stage, the relationships between soil types, surface microfeatures as indicators of soil degradation, physicochemical properties, plant colonization and vegetation structure were studied by means of multivariate statistical analyses (PCA, DCA, CCA and TWINSPAN®). Aerial photographs interpretation, DEMs and field surveys allowed us to identify 47 different environments for abandoned fields along 7 altitudinal transects (33 abandoned field terraces). In each study site, an inventory of the existing plant species and of morphological surface microfeatures were also made, by the line‐intercept method.

Plant colonization in the field plots studied relates to the variation of soils properties according to a climatic altitudinal gradient. The soil properties most closely related to the abandonment age (decrease of soil salinity and clay content, and increase of soil alkalinity and total organic C and N), have contributed to the growth of plant communities with a high degree of climacity.

The protection degree offered to the soils by the different vegetation types as a function of their structure and life‐forms strongly determines the occurrence of the different soil surface microfeatures as indicators of soil degradation or recovery.

The acceleration of the early stages of succession by active planting of seeds from shrub species in the lower and upper areas, followed by reforestation in the latter ones, may be the best improvement practices to achieve an effective ecological recovery of the fields and simultaneously to attenuate soil degradation. The reassuming of agriculture may be desirable in those fields placed in middle heights, provided they show the best soil and climate conditions. Copyright © 2006 John Wiley & Sons, Ltd.
The application of photodynamic therapy in the treatment of metastatic endobronchial disease
Authors: Magro Cynthia M. , Abbas Abbas E. , Ross Patrick
Published: May 2006

Background and Objective

We utilized photodynamic therapy (PDT) for palliation of metastatic endobronchial tumors employing sensitization with synthetic porphyrin, application of non‐thermal light, and endoscopic debridement of necrotic tumor.

Study Design/Materials and Methods

Nine patients with symptomatic endobronchial metastasis from carcinomas of the colon(3), breast(3), kidney(2), and tongue(1) received PDT.

Results

After two PDT treatments, patients showed substantial response, which was complete in all but one. One patient had perioperative complications and expired 2 days after developing massive hemoptysis during tumor debridement. Patient survival was 6.38 months (mean) and 4.2 months (median). Most patients died from advanced metastatic disease. One patient with metastasis limited to the airway is still alive 24 months following endobronchial presentation.

Conclusions

PDT ameliorates symptoms of metastatic airway obstruction, is easy to apply, has low morbidity and improves the quality of life. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Targeted photodynamic therapy
Authors: Solban Nicolas , Rizvi Imran , Hasan Tayyaba
Published: May 2006

Background and Objectives

Photodynamic therapy (PDT) is an emerging modality for the treatment of various neoplastic and non‐neoplastic pathologies.

Study Design/Materials and Methods

PDT usually occurs when reactive oxygen species (ROS) generated from light‐activated chemicals (photosensitizer, PS) destroy the target. For non‐dermatologic applications the PS are delivered systemically and accumulate, at different concentrations, in most organs.

Results and Conclusion

Typically there is a modest enhanced accumulation of the PS in tumor tissues, providing a first level of selectivity. Additional selectivity is provided by the confined illumination of the target area with the appropriate wavelength of light. For the treatment of pathologies in complex anatomical sites, such as in the peritoneal cavity, where restricted illumination is difficult; improved targeting of the PS is necessary to prevent damage to the surrounding healthy tissue. This article will focus on targeted PDT. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Photophysical and Electroluminescent Properties of Hyperbranched Polyfluorenes
Authors: Ding Liming , Bo Zhishan , Chu Qinghui , Li Jing , Dai Liming , Pang Yi , Karasz Frank E. , Durstock Michael F.
Published: May 2006

Summary: Properties of a series of hyperbranched polyfluorenes were investigated. Increasing the benzene “crosspoint” density blue‐shifts the absorption and PL since the crosspoints interrupt π‐electron conjugation, decreasing conjugation length, and thus increasing chromophore band gap. The relative intensity of S10 → S00 transition in PL increases with crosspoint density increase, indicating that the energy and the energy distribution of vibronic transitions were controlled by hyperbranch structure. When the polymer solution is cooled down, the lattice vibration is reduced and the effective conjugation length (coherence length for electron wavefunction) is increased, thus causing bathochromic shift in absorption and PL. These polymers do not favor excimer formation in solution due to their remarkable rigidity and extra‐large molecular size. With increase in crosspoint density, LED color changed from green to violet. In double‐layer LEDs, PPV not only improves hole injection/transport but also contributes to device emission through its bulk emission and interfacial emission as a result of interfacial energy transfer. Higher electrical field favors interfacial energy transfer probably by facilitating hole–electron recombination and by encouraging the excitons formed in polyfluorene layer to migrate to the interface and to further diffuse into PPV layer. The polymer with more crosspoints shows higher EL efficiency. The crosspoints interrupt π‐electron conjugation, isolate excitons and inhibit intrachain exciton annihilation. They can also increase rigidity of the macromolecular backbone, and the large spatial hindrance of these macromolecules makes the molecular packing very difficult, thus decreasing interchain exciton annihilation. All these structural features help to increase exciton lifetime and improve LED performance.

Synthesis of the hyperbranched polyfluorenes.

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Synthesis of the hyperbranched polyfluorenes.
Double Yielding in Injection‐Molded Polycarbonate/Polyethylene Blends: Composition Dependence
Authors: Pan Ji‐Lin , Li Zhong‐Ming , Ning Nan‐Ying , Yang Shuying
Published: May 2006

Summary: A fiber‐dependent double yielding phenomenon was recently observed in a structurally different blend, PC/HDPE, in which the first yield point is yielding of HDPE, and the second is caused by the yielding of injection‐induced PC fibers. The present study described the composition dependence of the double yielding in PC/HDPE blends with PC contents ranging from 0 to 45 wt.‐%. Morphology observation indicated that the injection‐molded PC/HDPE blends displayed a typical skin‐core structure with more or less injection‐induced elongated PC particles in the sub‐skin layers, and spherical PC particles in the core layers. Stress‐strain curves indicated that the blends with PC contents from 10 to 20 wt.‐% exhibit double yielding behavior and the cold drawing zone after the second yield point shortens with increasing PC content. The blends with too low‐ or too high‐PC contents exhibited only one yield point. Scanning electronic microscope micrographs of the blend with 15 wt.‐% PC showed that when the strain was beyond the first yield point the PC fibers notably yielded and even were broken, which served as an evidence that the yielding of PC phase was responsible for the second yielding. The origin of the composition dependence of the double yielding was discussed in detail through the interfacial stress transfer.

Representative stress‐strain curves for PE10, PE15, PE17.5, and PE20.

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Representative stress‐strain curves for PE10, PE15, PE17.5, and PE20.
Structure and Properties of Maleated Linear Low‐Density Polyethylene and Cellulose Acetate Butyrate Blends
Authors: Kosaka Priscila M. , Kawano Yoshio , Fantini Márcia C. A. , Petri Denise F. S.
Published: May 2006

Summary: Blends of M‐LLDPE and CAB were prepared in an internal laboratory mixer with 5, 10, 20, 30, 40 and 50 wt.‐% of CAB. Structure and properties of the blends were studied by means of tensile tests, DSC, SEM, extraction with a selective solvent, Raman spectroscopy and XRD. Blends prepared with 5 and 10 wt.‐% of CAB displayed the best mechanical properties. SEM and extraction with a selective solvent followed by Raman spectroscopy showed good interfacial adhesion between CAB and M‐LLDPE. No significant change on the melting temperatures (Tm) of the M‐LLDPE/CAB blends could be observed when compared with the Tm obtained for pure M‐LLDPE. XRD demonstrated that the addition of CAB has no influence on the lattice constants of M‐LLDPE, but the introduction of CAB increased the amorphous region, confirming that the miscibility occurs on the amorphous region of the polyethylene.

SEM image of the cryofracture surface of CAB‐20%.

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SEM image of the cryofracture surface of CAB‐20%.
Curing Kinetics of Diglycidyl Ether of Bisphenol A and Diaminodiphenylmethane Using a Mechanistic Model
Authors: Liu Guodong , Zhao Bin , Zhou Xiaofang , Wang Jiaxi , Gao Jungang , Qu Xiongwei , Zhang Liucheng
Published: May 2006

Summary: The curing kinetics of diglycidyl ether of bisphenol A (DGEBA) and 4,4′‐diaminodiphenylmethane (DDM) was analyzed using isothermal differential scanning calorimetry (DSC) modes by using a simple mechanistic model which includes two rate constants, k1 and k2, two reaction orders, n1 and n2, and the ratio of initial concentration of hydroxyl group to initial epoxy concentration, c0. Analyses of DSC data indicated that an autocatalytic reaction existed in the curing process. The mechanistic model proposed in this paper fits the experimental data exactly. Rate constants, k1 and k2 have been found to increase with rising curing temperature. The activation energies for the relative reactions were determined to be 66.00 ± 4.21 and 50.74 ± 8.92 kJ/mol, respectively. The complex equivalent constant, K, decreased with increasing temperature. Diffusion control was incorporated to describe the cure in the latter stages.

Comparison of experimental data with the mechanistic model for the curing kinetics of DGEBA with DDM.

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Comparison of experimental data with the mechanistic model for the curing kinetics of DGEBA with DDM.
Morphologies of Diblock Copolymer/Homopolymer Blend Films
Authors: Huang Yongmin , Liu Honglai , Hu Ying
Published: May 2006

Summary: Using bond length fluctuation and cavity diffusion algorithm, the morphologies of diblock copolymer/homopolymer blend films, AB/C and AB/A, confined between two hard walls are studied via Monte Carlo (MC) simulation on a cubic lattice. For the AB/C film, the C homopolymer is supposed to be more compatible with the A block than with the B block, while A and B are mutually incompatible. Effects of the composition of the diblock copolymer/homopolymer mixture, the symmetry of the diblock copolymer chain, the film thickness and the selective wall field on morphologies are studied in detail. Furthermore, the simulated results are compared with that of corresponding ABA and ABC triblock copolymer thin films. Comparisons with experiments and SCF theory also show good agreement. The results indicate that both the AB/C and AB/A can be used to prepare porous AB diblock copolymer membranes, the size of the pore channel can be controlled by the volume fraction of homopolymer C or homopolymer A.

Morphology of A6B14/C10 polymer blend film.

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Morphology of A6B14/C10 polymer blend film.
c‐jun/AP‐1 activation does not affect the antiproliferative activity of phenethyl isothiocyanate, a cruciferous vegetable‐derived cancer chemopreventive agent
Authors: Yao Song , Zhang Yuesheng , Li Jun
Published: May 2006

Cruciferous vegetable‐derived isothiocyanates (ITCs) display potent cancer chemopreventive activity, but also markedly stimulate oncogenic activator protein 1 (AP‐1). AP‐1 is well known to promote cell survival and proliferation. We examined the impact of AP‐1 activation on antiproliferative activity of ITCs, using bladder cancer cells and phenethyl isothiocyanate (PEITC) as models. AP‐1 transactivation induced by PEITC was almost completely suppressed by a dominant‐negative c‐jun (TAM67). However, suppression of AP‐1 transactivation did not affect PEITC‐induced apoptosis or cell‐cycle arrest. Moreover, we previously showed that in response to ITC treatment c‐jun was predominantly stimulated among AP‐1 family members largely by c‐jun N‐terminal kinase (JNK) [Food Chem Toxicol 2005; 43: 1373–1380], but neither JNK inhibition nor forced expression of c‐jun altered the antiproliferative activity of PEITC. In addition, cyclin D1, which is considered as an AP‐1 target gene and promotes cell proliferation, was markedly elevated in PEITC‐treated cells. Unexpectedly, neither TAM67 or JNK inhibition, nor forced c‐jun expression had a significant impact on cyclin D1 induction by PEITC, indicating that c‐jun/AP‐1 does not play an important role in cyclin D1 induction by PEITC. In conclusion, despite the known role of c‐jun/AP‐1 as a stimulator of cell growth and proliferation, our data show that its activation does not diminish the antiproliferative activity of PEITC and is not responsible for cyclin D1 induction by PEITC. © 2006 Wiley‐Liss, Inc.
Dietary agents as histone deacetylase inhibitors
Authors: Myzak Melinda C. , Ho Emily , Dashwood Roderick H.
Published: May 2006

In cancer cells, an imbalance often exists between histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities, and various drug companies are actively seeking competitive HDAC inhibitors for chemotherapeutic intervention. Cancer cells appear to be more sensitive than nontransformed cells to HDAC inhibitors, which disrupt the cell cycle and induce apoptosis via derepression of genes such as P21 and BAX. However, in the search for potent HDAC inhibitors with cancer therapeutic potential, a tendency exists to overlook or dismiss weak ligands that could prove effective in cancer prevention. Butyrate, diallyl disulfide (DADS), and sulforaphane (SFN) are three dietary agents that exhibit HDAC inhibitory activity in vitro and/or in vivo, and other such dietary agents probably will be discovered that affect HDAC activity. We make the distinction between ‘pharmacologic’ agents that potently derepress gene expression, during therapeutic intervention, and dietary HDAC inhibitors that, as weak ligands, might subtly regulate the expression of genes involved in cell growth and apoptosis. An important issue for future study is to determine the extent to which dietary HDAC inhibitors, by modulating genes such as p21 and Bax, enable normal, nontransformed cells to respond most effectively to external stimuli and toxic insults. © 2006 Wiley‐Liss, Inc.
On Cauchy estimates and growth orders of entire solutions of iterated Dirac and generalized Cauchy–Riemann equations
Authors: Constales D. , De Almeida R. , Kraußhar R. S.
Published: May 2006

In this paper, we study the growth behaviour of entire Clifford algebra‐valued solutions to iterated Dirac and generalized Cauchy–Riemann equations in higher‐dimensional Euclidean space. Solutions to this type of systems of partial differential equations are often called k‐monogenic functions or, more generically, polymonogenic functions. In the case dealing with the Dirac operator, the function classes of polyharmonic functions are included as particular subcases. These are important for a number of concrete problems in physics and engineering, such as, for example, in the case of the biharmonic equation for elasticity problems of surfaces and for the description of the stream function in the Stokes flow regime with high viscosity.

Furthermore, these equations in turn are closely related to the polywave equation, the poly‐heat equation and the poly‐Klein–Gordon equation.

In the first part we develop sharp Cauchy‐type estimates for polymonogenic functions, for equations in the sense of Dirac as well as Cauchy–Riemann. Then we introduce generalizations of growth orders, of the maximum term and of the central index in this framework, which in turn then enable us to perform a quantitative asymptotic growth analysis of this function class. As concrete applications we develop some generalizations of some of Valiron's inequalities in this paper. Copyright © 2006 John Wiley & Sons, Ltd.
Predicting heat inactivation of Staphylococcus aureus under nonisothermal treatments at different pH
Authors: Hassani Mounir , Mañas Pilar , Condón Santiago , Pagán Rafael
Published: May 2006

The aim was to assess whether heat resistance data obtained from isothermal treatments allow the estimation of survivors of Staphylococcus aureus under nonisothermal conditions and to find a model that accurately predicts its heat inactivation at constantly rising heating rates (0.5–9°C/min) in media of different pH (4.0–7.4). S. aureus showed a higher heat resistance under isothermal treatments at pH 4.0 than at pH 5.5–7.4. However, under nonisothermal treatments S. aureus increased its heat resistance at pH 5.5–7.4 and became more thermotolerant than at pH 4.0. Estimations of survival curves under nonisothermal treatments obtained from heat resistance parameters of isothermal treatments did not adequately fit experimental values. Whereas the number of survivors was much higher than estimated at pH 5.5–7.4, that obtained at the slower heating rates at pH 4.0 was lower. An equation based on the Weibullian‐like distribution (log10S(t) = (t/δ)p) accurately described survival curves obtained under nonisothermal conditions. A nonlinear relationship was observed among the scale parameter (δ) and the heating rate which allowed the development of two equations capable of predicting the inactivation rate of S. aureus under nonisothermal treatments. This study might contribute to prevent public health risks in foods requiring long heating lag phases during their processing.
Evidence of a new dechlorinated ochratoxin A derivative formed in opossum kidney cell cultures after pretreatment by modulators of glutathione pathways: Correlation with DNA‐adduct formation
Authors: Faucet‐Marquis Virginie , Pont Frédéric , Størmer Frederik C. , Rizk Toufik , Castegnaro Marcel , Pfohl‐Leszkowicz Annie
Published: May 2006

Ochratoxin A (OTA), a nephrotoxic mycotoxin probably implicated in human Balkan endemic nephropathy and associated urothelial tumors, induces renal carcinomas in rodents and nephrotoxicity in pigs. OTA induces DNA‐adduct formation, but the structure of the adducts and their role in nephrotoxicity and carcinogenicity have only partly been elucidated. In vivo, 2‐mercaptoethane sulfonate (MESNA) protects rats against OTA‐induced nephrotoxicity but not against carcinogenicity, indicating two different mechanisms leading to nephrotoxicity or carcinogenicity. To better understand how DNA‐adduct could be generated, opossum kidney cells (OK) have been treated by OTA alone or in presence of several compounds such as MESNA or N‐acetylcysteine (another agent that, like MESNA, reduces oxidative stress by increasing of free thiols in kidney), buthionine sulfoximine (BSO) (an inhibitor of glutathione‐synthase), and alpha amino‐3‐chloro‐4,5‐dihydro‐5‐isoxazole acetic acid (ACIVICIN) (an inhibitor of gamma glutamyl transpeptidase). Cytotoxicity of OTA on OK cells was evaluated by applying the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. None of the listed agents diminished OTA cytotoxicity significantly; ACIVICIN even increases OTA cytotoxicity. In contrast, analysis of the HPLC profiles of OTA metabolites produced during these incubations indicated that the pattern, the quantity of metabolites, and the nature of the derivatives were modulated by these agents. Ochratoxin B (OTB), open‐ring ochratoxin A (OP‐OA), 4 hydroxylated OTA, 10 hydroxylated OTA, OTA without phenylalanine, OTB without phenylalanine, and a dechlorinated OTA metabolite could be identified by nano‐ESI‐IT‐MS.
Advantages and drawbacks of immunoaffinity columns in analysis of mycotoxins in food
Authors: Castegnaro Marcel , Tozlovanu Marianna , Wild Christopher , Molinié Anne , Sylla Abdoulay , Pfohl‐Leszkowicz Annie
Published: May 2006

A number of countries are setting legislations on mycotoxins. In order to reduce dispute between importing and exporting countries, the analytical data should be as comparable as possible, especially when levels are close to the regulatory limits. The present trend in the analysis of mycotoxins is to use immunoaffinity column (IAC) as a clean‐up and enrichment technique, and Association of Official Analytical Chemists and European Union have validated methods which address a few food commodities. This study describes our experience using both conventional and IAC approaches in the analysis of three mycotoxins. Aflatoxins (AFs): Aflatoxin G1 has been detected by liquid–liquid partitioning methods with HPLC detection as false‐positive in some maize. On IACs, this compound behaves as an AF, lowering the amount of the AFs trapped. The problem was solved using either TLC or HPLC with detection in the Kobra cell®. Depending on the additives to food during the processing and cooking, the AFs might appear as an opened ring not recognised by the antibody. Fumonisins (FB): Compounds interfering with the FB's antibodies were also observed while analysing breakfast cereals leading to underestimation of FB. Ochratoxin A (OTA): Depending on the food composition and extraction techniques, OTA is underestimated with IAC in some breakfast cereals and coffee. These data strengthen the necessity to validate methods using IAC for each complex matrix.
Computed coupling constants in X(CH3)nH(4–n) moieties where X = 13C and 15N+, and n = 0–4: comparisons with experimental data
Authors: Jimeno María‐Luisa , Alkorta Ibon , Elguero José , Del Bene Janet E.
Published: May 2006

Seventy‐three unique spin–spin coupling constants have been analyzed for the ten species in the two series X(CH3)nH4–n, where the central atom X is 13C or 15N+. Thirty‐seven experimental values have been obtained from the literature, and several new coupling constants have been measured for the methyl‐substituted ammonium ions. Both DFT with the B3LYP functional and ab initio EOM‐CCSD calculations have been carried out on these same systems. Coupling constants computed by these two methods are in agreement with experimental values. Some problems related to coupling constants for the cationic ammonium systems have been resolved when these were recomputed at EOM‐CCSD for complexes in which NH4+ is hydrogen‐bonded to H2O molecules. Copyright © 2006 John Wiley & Sons, Ltd.
Genetic risk factors associated with lipid‐lowering drug‐induced myopathies
Authors: Vladutiu Georgirene D. , Simmons Zachary , Isackson Paul J. , Tarnopolsky Mark , Peltier Wendy L. , Barboi Alexandru C. , Sripathi Naganand , Wortmann Robert L. , Phillips Paul S.
Published: May 2006

Lipid‐lowering drugs produce myopathic side effects in up to 7% of treated patients, with severe rhabdomyolysis occurring in as many as 0.5%. Underlying metabolic muscle diseases have not been evaluated extensively. In a cross‐sectional study of 136 patients with drug‐induced myopathies, we report a higher prevalence of underlying metabolic muscle diseases than expected in the general population. Control groups included 116 patients on therapy with no myopathic symptoms, 100 asymptomatic individuals from the general population never exposed to statins, and 106 patients with non–statin‐induced myopathies. Of 110 patients who underwent mutation testing, 10% were heterozygous or homozygous for mutations causing three metabolic myopathies, compared to 3% testing positive among asymptomatic patients on therapy (P = 0.04). The actual number of mutant alleles found in the test group patients was increased fourfold over the control group (P < 0.0001) due to an increased presence of mutation homozygotes. The number of carriers for carnitine palmitoyltransferase II deficiency and for McArdle disease was increased 13‐ and 20‐fold, respectively, over expected general population frequencies. Homozygotes for myoadenylate deaminase deficiency were increased 3.25‐fold with no increase in carrier status. In 52% of muscle biopsies from patients, significant biochemical abnormalities were found in mitochondrial or fatty acid metabolism, with 31% having multiple defects. Variable persistent symptoms occurred in 68% of patients despite cessation of therapy. The effect of statins on energy metabolism combined with a genetic susceptibility to triggering of muscle symptoms may account for myopathic outcomes in certain high‐risk groups. Muscle Nerve, 2006
Global ratings of patient satisfaction and perceptions of improvement with treatment for urinary incontinence: Validation of three global patient ratings
Authors: Burgio Kathryn L. , Goode Patricia S. , Richter Holly E. , Locher Julie L. , Roth David L.
Published: May 2006

Aims

To test the validity of three patient global ratings, satisfaction, perception of improvement, and estimated percent improvement, for measuring outcomes of behavioral treatment for urinary incontinence.

Methods

This report is a secondary analysis of data from three randomized controlled trials testing behavioral interventions for incontinence. Participants were 359 community‐dwelling women, aged 40–92 years, with stress, urge, or mixed urinary incontinence. All participants received an 8‐week program of clinic‐based or self‐administered behavioral training. Subjective outcomes included a patient satisfaction question (PSQ), global perception of improvement (GPI), and estimated percent improvement (EPI). Convergent validity was tested by examining the relationship between each measure and reduction of incontinence (bladder diary), change on the incontinence impact questionnaire (IIQ), and desire for another treatment. Discriminant validity was explored by examining the relationship of the global ratings to five measures not expected to be related to outcome (age, race, BMI, education level, and change in perceived pain).

Results

All three patient global ratings were significantly associated with each other (P < 0.0001), with diary measures of reduction of incontinence episodes (P < 0.0001), and change in the IIQ (P < 0.005), and inversely associated with desire for another treatment (P < 0.0001). All three patient ratings were not significantly associated with age, race, BMI, education level, or change in perceived pain.

Conclusion

Patient global ratings of satisfaction, perception of improvement, and estimated percent improvement have acceptable convergent and discriminant validity for measuring outcomes in studies of behavioral treatment for urinary incontinence. Neurourol. Urodynam. Published 2006 Wiley‐Liss, Inc.
Construct validity of the incontinence severity index
Authors: Murphy Miles , Culligan Patrick J. , Arce Cristina M. , Graham Carol A. , Blackwell Linda , Heit Michael H.
Published: May 2006

Aims

To assess the construct validity of the incontinence severity index (ISI) by testing its correlation with two health‐related quality of life measures, the short forms of the Urogenital Distress Inventory (UDI‐6) and the Incontinence Impact Questionnaire (IIQ‐7), in women with urodynamic stress incontinence.

Materials and Methods

A cohort of 170 women with the urodynamic stress incontinence who underwent corrective surgery completed the ISI, IIQ‐7, and the UDI‐6 both pre‐ and post‐treatment. We correlated the pre‐ and post‐treatment responses between the ISI, the IIQ‐7, the UDI‐6 and their subscales. We also assessed the sensitivity of the ISI to change by correlating the percent change in score between the three instruments. The results were analyzed using a non‐parametric test of correlation, the Spearman's rho.

Results

The ISI scores were generally not well correlated with the pre‐treatment IIQ‐7 and UDI‐6 scores (r < 0.40). The post‐treatment scores and percent change from pre‐ to post‐treatment of the ISI, however, were highly correlated with that of the IIQ‐7 and UDI‐6 (r's > 0.70, P < 0.001). The ISI was most highly correlated with the UDI‐6 stress symptoms subscale and most poorly correlated with the UDI‐6 obstructive/discomfort subscale.

Conclusions

This study provides valuable insight into the construct validity of the ISI. Evidence of its convergent validity is found in the high correlation with the stress symptoms subscales of the UDI‐6, while the poorer correlation with the obstructive subscale provides evidence of its divergent validity. These data also suggest that the ISI is highly sensitive to change seen with treatment. Neurourol. Urodynam. 25:418–423, 2006. © 2006 Wiley‐Liss, Inc.
Photo‐differential scanning calorimetry study on photopolymerization of nanosized titanium dioxide/polyacrylate hybrid materials
Authors: Tao Wan , Fei Feng , Rong Ran , Yue‐Chuan Wang
Published: May 2006

Nanosized titania–polyacrylate hybrid films were prepared by controlled hydrolysis of titanium tetrabutoxide (TTB) in Span 85/Tween 80 reverse micelles as well as rapid entrapment of nanosized particles by subsequent photopolymerization. This work focused on the characterization of the photopolymerization of the transparent hybrid films via photocalorimetry. The polymerization kinetics of several mixtures of mono‐ and di‐functional acrylate monomers were compared to examine the effect of average functionality. Further, Effects of [H2O]/[surfactant] molar value and TTB concentration on photopolymerization kinetics were also studied. X‐ray photoelectron spectra and FTIR demonstrated the formation of TiO2 in the hybrid films. Atomic Force Microscope (AFM) images showed the inorganic domains with mean sizes of 25 nm were uniformly dispersed in the polymeric networks. Copyright © 2006 Society of Chemical Industry
Chemical natures and distributions of metal impurities in multicrystalline silicon materials
Authors: Buonassisi T. , Istratov A. A. , Pickett M. D. , Heuer M. , Kalejs J. P. , Hahn G. , Marcus M. A. , Lai B. , Cai Z. , Heald S. M. , Ciszek T. F. , Clark R. F. , Cunningham D. W. , Gabor A. M. , Jonczyk R. , Narayanan S. , Sauar E. , Weber E. R.
Published: May 2006

We present a comprehensive summary of our observations of metal‐rich particles in multicrystalline silicon (mc‐Si) solar cell materials from multiple vendors, including directionally‐solidified ingot‐grown, sheet, and ribbon, as well as multicrystalline float zone materials contaminated during growth. In each material, the elemental nature, chemical states, and distributions of metal‐rich particles are assessed by synchrotron‐based analytical x‐ray microprobe techniques. Certain universal physical principles appear to govern the behavior of metals in nearly all materials: (a) Two types of metal‐rich particles can be observed (metal silicide nanoprecipitates and metal‐rich inclusions up to tens of microns in size, frequently oxidized), (b) spatial distributions of individual elements strongly depend on their solubility and diffusivity, and (c) strong interactions exist between metals and certain types of structural defects. Differences in the distribution and elemental nature of metal contamination between different mc‐Si materials can largely be explained by variations in crystal growth parameters, structural defect types, and contamination sources. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and characterization of new radiopaque microspheres by the dispersion polymerization of an iodinated acrylate monomer for X‐ray imaging applications
Authors: Galperin Anna , Margel Shlomo
Published: May 2006

Radiopaque microspheres of sizes ranging from 0.2 to 1.4 μm were formed by the dispersion polymerization of the monomer 2‐methacryloyloxyethyl(2,3,5‐triiodobenzoate) in 2‐methoxyethanol. The effects of various polymerization parameters, including the monomer concentration, initiator type and concentration, and stabilizer molecular weight and concentration, on the molecular weight, size, and size distribution of the particles were elucidated. The characterization of these iodinated microspheres was accomplished with routine methods such as Fourier transform infrared, nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, scanning electron microscopy, Brunauer–Emmett–Teller measurements, and elemental analysis. Because of the presence of iodine atoms in these microspheres, they were expected to possess a radiopaque nature. The radiopacity of these particles dispersed in water and in the dry state was demonstrated with an imaging technique based on X‐ray absorption usually used in hospitals. These novel radiopaque microspheres may be used for different X‐ray imaging needs, such as blood pooling, body organs, embolization, dental compositions, implants, prostheses, and nanocomposites. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3859–3868, 2006
Synthesis and self‐assembly of polystyrene‐grafted multiwalled carbon nanotubes with a hairy‐rod nanostructure
Authors: Yang Yingkui , Xie Xiaolin , Wu Jingao , Mai Yiu‐Wing
Published: May 2006

Polystyrene‐grafted multiwalled carbon nanotubes (PS‐g‐MWNTs) with a hairy‐rod nanostructure were synthesized by the in situ free‐radical polymerization of styrene in the presence of multiwalled carbon nanotubes (MWNTs) terminated with vinyl groups. To quantitatively study the molecular weight and composition of polystyrene (PS) chains in PS‐g‐MWNTs, PS‐g‐MWNTs were fully defunctionalized by hydrolysis. The results showed that 1 of every 100 carbon atoms in MWNTs was functionalized at the tips and outer walls of the carbon nanotubes and grafted by PS with a weight‐average molecular weight of 9800 g/mol; therefore, a uniform thin layer (ca. 8–10 nm) of a PS shell was formed on the outer wall of MWNTs. PS‐g‐MWNTs were soluble in dimethylformamide and tetrahydrofuran. The thermal stability and glass‐transition temperature of PS in PS‐g‐MWNTs were obviously increased. Nanopins were formed on the glass substrates by the self‐assembly of PS‐g‐MWNTs, and the dewetting effect between the glass substrate and PS chains covered MWNTs during the evaporation of the solution. Both the length and diameter of the nanopins increased with the solution concentration. When PS‐g‐MWNTs were compression‐molded, MWNTs were dispersed uniformly in the PS matrix and formed good networks, such as circlelike and starlike structures, because of the entanglements of hairy PS chains on MWNTs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3869–3881, 2006
Mass spectrometrical verification of stomatin‐like protein 2 (SLP‐2) primary structure
Authors: Pradeep John Julius Paul , Anrather Dorothea , Pollak Arnold , Lubec Gert
Published: May 2006

Stomatin‐like protein 2 (SLP‐2) (syn.: EPB72‐like 2 [NP_038470], HSPC108 [AAF29073]), a protein of unknown function, has been described in several tissues and cells but its primary structure is still not completely elucidated. Moreover, sequence conflicts appear in several databases. It was the aim of the study to further describe SLP‐2 primary sequence and to solve existing sequence conflicts. For this purpose a protein extract was run on two‐dimensional gel electrophoresis and SLP‐2 was identified by MALDI‐TOF/TOF. SLP‐2 was digested with trypsin, chymotrypsin, Lys‐C, and de novo sequencing studies as well as Nano‐HPLC‐ESI‐MS/MS analysis were carried out. By the use of several proteases sequence coverage of 90% was obtained but the N‐terminal 34 amino acids harbouring database conflict 1 were not covered. The presence of Leucine 129 (sequence conflict 2) and Alanine 202 (sequence conflict 3) was verified by three independent approaches. High sequence coverage resulting from multiple proteolytic cleavage, MALDI‐TOF/TOF, Nano‐HPLC‐ESI‐MS/MS and de novo sequencing completed unambiguous analysis of SLP‐2 primary structure of ≈90% of sequence coverage. In addition, methodology used was able to solve so far pending sequence conflicts in databases and literature. SLP‐2 is a high abundance protein in several tissues and cells and may play an important biological role and therefore characterization of its primary structure is of importance. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Cover Picture: Rapid Research Letter – Focusing slabs made of negative index materials based on inhomogeneous dielectric rods
Authors: Sergentu V. V. , Ursaki V. V. , Tiginyanu I. M. , Foca E. , Föll H. , Boyd Robert W.
Published: May 2006

In the Rapid Research Letter [1] it is shown that a flat array of dielectric rods can act as a focusing lens of good quality – provided the rods have specified gradients of the dielectric constant. This design is superior to conventional photonic crystals (PC) utilizing homogeneous rods since the “lens” can be smaller and has better properties in a broader wavelength range.

The cover picture is an artist's view of the PC lens made from dielectric rods consisting of three layers with the refractive index increasing from the margin to the center of the rod, focusing a light beam into a small spot. The focusing spot is controlled by the parameters of the rods and their arrangement in the PC slab.

The first author, Dr. Vladimir Sergentu, is a senior researcher of the Laboratory of Low Dimensional Semiconductor Structures in Chisinau, Moldova, which works on the design of PC based optical elements in collaboration with the Universities of Kiel and Rochester.
Photoluminescence in implanted and doped silicon near room temperature
Authors: Matsubara Ichiro , Sasahara Shingo , Mishina Tomobumi , Ishibashi Yasuhiko , Kobayashi Toshihiko , Nakahara Jun'ichiro
Published: May 2006

Photoluminescence in implanted and doped silicon at room temperature is measured, and the observed structures are assigned as intrinsic phonon‐assisted indirect allowed transitions. The temperature of photoexcited carriers, which is higher than the bath temperature, is estimated. For confined carriers produced by boron implantation the temperature dependence of the effective temperature of the excited carriers is the same for the different samples, but an enhancement of the photoluminescence is observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1H NMR spin–lattice relaxation studies in Betaine phosphate (BP) – Transition from classical to quantum rotation
Authors: Ramanuja M. N. , Ramesh K. P. , Ramakrishna J.
Published: May 2006

We report here the results of our 1H NMR spin–lattice relaxation time (T 1) studies in betaine phosphate which is ferroelectric below 86 K and antiferroelectric below 81 K. The experiments have been carried out in the temperature range 300 to 4 K, at two Larmor frequencies 11.4 and 23.3 MHz. The T 1 data (300–100 K) has been analysed using modified BPP equation based on Ikeda's model. CH3 protons are found to relax other protons via spin diffusion. The low temperature (T < 100 K) T 1 data has been analysed following Lourens model which considers the gradual transition from classical motions to quantum regime. At low temperatures, when classical processes tend to freeze, reorienting groups apparently have minute differences and hence create a distribution in the energy values (E a and E 01) and pre‐exponential factors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of off‐diagonal dielectric response on optical properties of LaTiO3
Authors: Krasovska O. V. , Antonov V. N. , Krasovskii E. E. , Schattke W.
Published: May 2006

Optical spectra of LaTiO3 are analyzed on the basis of an ab initio macroscopic dielectric function. The energy band structure and microscopic dielectric matrix are calculated with the extended linear augmented plane wave (ELAPW)‐k · p method. The origin of UV spectral structures is elucidated. LaTiO3 is compared with SrTiO3 and BaTiO3 perovskites, and chemical trends in the formation of the UV reflectivity are discussed. The inclusion of local field corrections shifts spectral structures due to semi‐core La 5p and Ti 3p excitations by several eV to higher energies. Calculated reflectivity and optical conductivity curves agree well with the experiment. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localized excitons and defects in PbWO4 single crystals: a luminescence and photo‐thermally stimulated disintegration study
Authors: Krasnikov A. , Nikl M. , Zazubovich S.
Published: May 2006

Luminescence from the exciton‐ and defect‐related states and photo‐thermally stimulated disintegration of these states under selective UV irradiation were studied in the PbWO4:Mo, Ce crystal and compared with the characteristics of other undoped and doped PbWO4 crystals of different origin. For the first time, various localized exciton states were identified and their decay into stable defects was found. Different positions, halfwidths and temperature dependences were observed for the blue emission spectrum in different PbWO4 crystals and explained by the presence of strongly overlapping emission bands of the WO42–‐type self‐trapped and localized excitons. Binding energies of the self‐trapped and localized exciton states were calculated. The dominant thermally stimulated luminescence peaks, created in the PbWO4:Mo, Ce crystal by the UV radiation, are located at 110, 202 and 247 K. The related trap depths were calculated using the initial rise method. It was concluded that under irradiation in the exciton absorption region, defects are mainly created due to the disintegration of the localized exciton states, which occurs without release of free charge carriers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some Properties of Starch Isolated from Radix Cynanchi bungei
Authors: Song Zhi‐Gang , Wang Jian‐Hua , Wang Han‐Zhong , Zhao Ai‐Hong , Liu Chun‐Xiao , Tian Ji‐Chun
Published: May 2006

The physicochemical and scanning electron micrograph characteristics of Radix Cynanchi bungei (RCb) starch were investigated. RCb starch presented an apparent amylose content of 20.1%, less than that of potato starch (23.6%), with a granule size ranging from 5 to 15 μm with round, spherical and polygonal shapes and B‐type X‐ray diffraction pattern. The RVA pasting properties of RCb starch were similar to those of potato starch, with pasting temperature of 60.8°C, lower than that of potato starch (64.3°C). The gelatinization parameters of RCb starch were found to be 55.9°C (To), 60.0°C (Tp), 66.6°C (TC) and 13.2 J/g (ΔH) while those of potato starch were 58.9°C, 63.5°C, 68.6°C and 13.2 J/g. Both RCb and potato starch pastes behaved as high shear‐thinning liquids. RCb starch pastes had lower apparent viscosity than potato starch pastes at the same shear rate.