bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Bistable Molecular Switch Driven by Photoinduced Hydrogen‐Atom Transfer
Authors: Lapinski Leszek , Nowak Maciej J. , Nowacki Jacek , Rode Michat F. , Sobolewski Andrzej L. 
Published: July 2009

AbstractThe occurrence of photoinduced hydrogen atom transfer between two remote spots of a molecule is experimentally demonstrated. This photoprocess involves the intermediacy of an intramolecular “crane”. In an experimental case study, 7‐hydroxy‐4‐methylquinoline‐8‐carbaldehyde monomers isolated in low‐temperature Ar matrices are investigated. On UV (λ>295 nm) irradiation, a hydrogen atom is transferred from the O7H group to the N1 atom of the quinoline ring. Subsequent irradiation with UV (λ>360 nm) light reveals that the phototransformation is partially photoreversible. In the studied hydrogen‐atom‐transfer process, the exocyclic carbaldehyde group plays the role of an intramolecular crane. The possible application of systems analogous to 7‐hydroxy‐4‐methylquinoline‐8‐carbaldehyde as optically driven molecular switches is discussed.
DFT Study of Small Palladium Clusters Pdn and Their Interaction with a CO Ligand (n = 1–9)
Authors: Zanti Giuseppe , Peeters Daniel 
Published: July 2009

AbstractThis paper presents a theoretical study of palladium clusters Pdn of low nuclearity, ranging from 1 to 9, completed by their interactions with a carbonyl ligand (PdnCO). The simulations were performed at the DFT (B3LYP–Lanl2DZ) level. Small palladium clusters are deltahedral structures characterized by a triplet ground state (Pd2 to Pd7) or a quintet ground state for larger nuclearities (Pd8 and Pd9). Various electronic states relatively close in energy are present. These states have close geometries but differ by their electron density distribution. A significant electronic population of the 5s orbital is needed to explain the existence and cohesion of palladium–palladium bonds. These latter are formed by the combination of sd hybrid orbitals and get stronger as the 5s character increases. The relative stability of palladium clusters increases with their nuclearity and the study of fragmentation reactions shows a particular stability of Pd4, Pd6 and Pd9 clusters. The adsorption of the CO ligand goes through a back‐bonding interaction favoured by a high 4d and a low 5s atomic population. This interaction therefore affects the metal–metal bond and the ground state of the cluster becomes a singlet for the first members of the series. The favoured coordination mode is one that maximizes the back‐bonding interaction, i.e. the capped position (μ3) on a cluster's face. However, stabilization provided by the presence of one ligand at the expense of a large number of metal–metal bonds is not sufficient and, in the case of larger clusters, a triplet ground state remains.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Microalgal bioreactors: Challenges and opportunities
Authors: Xu Ling , Weathers Pamela J. , Xiong Xue‐Rong , Liu Chun‐Zhao 
Published: July 2009

AbstractCultivating and harvesting of products from microalgae has led to increasing commercial interest in their use for producing valuable substances for food, feed, cosmetics, pharmaceuticals, and biodiesel, as well as for mitigation of pollution and rising CO2 in the environment. This review outlines different bioreactors and their current status, and points out their advantages and disadvantages. Compared with open‐air systems, there are distinct advantages to using closed systems, but technical challenges still remain. In view of potential applications, development of a more controllable, economical, and efficient closed culturing system is needed. Further developments still depend on continued research in the design of photobioreactors and break‐throughs in microalgal culturing technologies.
The air‐lift photobioreactors with flow patterning for high‐density cultures of microalgae and carbon dioxide removal
Authors: Chiu Sheng‐Yi , Tsai Ming‐Ta , Kao Chien‐Ya , Ong Seow‐Chin , Lin Chih‐Sheng 
Published: July 2009

AbstractA photobioreactor containing microalgae is a highly efficient system for converting carbon dioxide (CO2) into biomass. Using a microalgal photobioreactor as a CO2 mitigation system is a practical approach to the problem of CO2 emission from waste gas. In this study, a marine microalga, Chlorella sp. NCTU‐2, was applied to assess biomass production and CO2 removal. Three types of photobioreactors were designed and used: (i) without inner column (i.e. a bubble column), (ii) with a centric‐tube column and (iii) with a porous centric‐tube column. The specific growth rates (μ) of the batch cultures in the bubble column, the centric‐tube and the porous centric‐tube photobioreactor were 0.180, 0.226 and 0.252 day−1, respectively. The porous centric‐tube photobioreactor, operated in semicontinuous culture mode with 10% CO2 aeration, was evaluated. The results show that the maximum biomass productivity was 0.61 g/L when one fourth of the culture broth was recovered every 2 days. The CO2 removal efficiency was also determined by measuring the influent and effluent loads at different aeration rates and cell densities of Chlorella sp. NCTU‐2. The results show that the CO2 removal efficiency was related to biomass concentration and aeration rate. The maximum CO2 removal efficiency of the Chlorella sp. NCTU‐2 culture was 63% when the biomass was maintained at 5.15 g/L concentration and 0.125 vvm aeration (volume gas per volume broth per min; 10% CO2 in the aeration gas) in the porous centric‐tube photobioreactor.
Scale up production of isoflavonoids in cell suspension cultures of Pueraria tuberosa grown in shake flasks and bioreactor
Authors: Sharma Varsha , Goyal Shaily , Ramawat Kishan Gopal 
Published: July 2009

AbstractCell cultures of Pueraria tuberosa were grown in vessels of different sizes and 2L stirred tank bioreactor containing modified MS medium with morphactin (0.1 mg l−1) and 2iP (5.0 mg l−1) and 20% inoculum. Stable growth and total isoflavonoid yield of 76.6 mg l−1 were recorded in the cultures during scale up. This was in concordance with the persistent yield of the individual isoflavonoids regardless of the vessel size.
Bioreactor for cultivation of red beet hairy roots and in situ recovery of primary and secondary metabolites
Authors: Neelwarne Bhagyalakshmi , Thimmaraju Rudrappa 
Published: July 2009

AbstractTo arrive at an appropriate bioreactor design and in situ recovery of the products, red beet hairy roots were used as a model system where the levels of betalain pigments (betacyanins and betaxanthins) were followed as secondary metabolite and the peroxidase enzyme as primary metabolite. Medium volume and other kinetic parameters were found to play significant roles by way of directly affecting the biomass yield rather than a specific metabolite. The hydrodynamic stress created on the roots by large culture volume could be minimized by pulse‐feeding of medium in shake‐flasks; and by separating the biomass chamber from the aerated medium reservoir in circulatory fed‐batch bioreactor. Accordingly the bioreactor was modified to provide anchorage and air‐enrichment chamber which resulted in higher formation of both the metabolites than in shake‐flasks. Various down‐stream processing aspects such as in situ release of pigments by non‐destructive methods, followed by adsorption through a column and recovery by desorption were optimized for betalains. A strategy for simultaneous recovery of pigment and peroxidase was worked out using aqueous two phase extraction (ATPE).
Design principles of photo‐bioreactors for cultivation of microalgae
Authors: Posten Clemens 
Published: July 2009

AbstractThe present hype in microalgae biotechnology has shown that the topic of photo‐bioreactors has to be revisited with respect to availability in really large scale measured in hectars footprint area, minimization of cost, auxiliary energy demand as well as maintenance and life span. This review gives an overview about present designs and the basic limiting factors which include light distribution to avoid saturation kinetics, mixing along the light gradient to make use of light/dark cycles, aeration and mass transfer along the vertical or horizontal main axis for carbon dioxide supply and oxygen removal and last but not least the energy demand necessary to fulfil these tasks. To make comparison of the performance of different designs easier, a commented list of performance parameters is given. Based on these critical points recent developments in the areas of membranes for gas transfer and optical structures for light transfer are discussed. The fundamental starting point for the optimization of photo‐bioprocesses is a detailed understanding of the interaction between the bioreactor in terms of mass and light transfer as well as the microalgae physiology in terms of light and carbon uptake kinetics and dynamics.
Body image in gay and straight men: A qualitative study
Authors: Morgan John F , Arcelus Jon 
Published: July 2009

AbstractObjectiveRecent research has emphasized vulnerability to eating disorders in gay men, with calls for research on causality, cultural factors and focus on a younger age cohort. This study aimed to examine body image and related eating behaviours in younger gay and straight men.MethodQualitative study using a sample of gay and straight male university students, applying audiotaped and transcribed depth interview subjected to interpretative phenomenological analysis.ResultsFifteen young men (18–24) with a spectrum of sexual orientation (gay, straight and bisexual) agreed to participate. Five dominant categories emerged: body image ideal, external influences, perception of body image, dieting, mechanisms for modification (diet, exercise, cosmetics) and sexual orientation.ConclusionHealth and aesthetic ideals appear less divorced for young men than women, offering some degree of protection from eating disorders. Nonetheless there is widespread body dissatisfaction. Media and social influences are powerful, particularly for single gay men, but the study suggests fewer differences than similarities between gay and straight men. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.
Reaction of N‐thioamido amidines with phosphoramide derivatives: Synthesis of 2‐substituted‐1,3,5,2‐triazaphosphorines
Authors: Raouafi Noureddine , Khlifi Akila , Boujlel Khaled , Benkhoud Mohamed Lamine 
Published: July 2009

AbstractThe reaction of N‐thioamido amidines 1 with tris(dimethylamino)phosphine or bis(diethylamino)phenylphosphine in refluxing toluene leads to the 1,3,5,2λ3‐triazaphosphorines 2 and 3, respectively. The condensation results in the release of two molecules of dialkylamine. The sulfuration of the trivalent phosphorus atoms was achieved by the reaction with elemental sulfur, followed by heating in toluene. The structure of the triazaphosphorines 2 and 3 and their thione derivatives 4 and 5 were readily elucidated by means of 1H, 13C, and 31P NMR spectroscopy and mass spectrometry. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:272–277, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20546
Inequality of opportunity in health: evidence from a UK cohort study
Authors: Rosa Dias Pedro 
Published: July 2009

AbstractThis paper proposes an empirical implementation of the concept of inequality of opportunity in health and applies this to data from the UK National Child Development Study. Drawing on the distinction between circumstance and effort variables in John Roemer's work on equality of opportunity, circumstances are proxied by parental socio‐economic status and childhood health; effort is proxied by health‐related lifestyles and educational attainment. Stochastic dominance tests are used to detect inequality of opportunity in the conditional distributions of self‐assessed health in adulthood. Two alternative approaches are used to measure inequality of opportunity. Econometric models are estimated to illuminate and quantify the triangular relationship between circumstances, effort and health. The results indicate the existence of a considerable and persistent inequality of opportunity in health. Circumstances affect health in adulthood both directly and through effort factors such as educational attainment. This indicates that, while the influence of some unjust circumstances can only be tackled during childhood, the implementation of complementary educational policies may be of paramount importance. Copyright © 2009 John Wiley & Sons, Ltd.
The effects of an incentive program on quality of care in diabetes management
Authors: Scott Anthony , Schurer Stefanie , Jensen Paul H. , Sivey Peter 
Published: July 2009

AbstractAn incentive program for general practitioners to encourage systematic and igh‐quality care in chronic disease management was introduced in Australia in 1999. There is little empirical evidence and ambiguous theoretical guidance on which effects to expect. This paper evaluates the impact of the incentive program on quality of care in diabetes, as measured by the probability of ordering an HbA1c test. The empirical analysis is conducted with a unique data set and a bivariate probit model to control for the self‐selection process of practices into the program. The study finds that the incentive program increased the probability of an HbA1c test being ordered by 20 percentage points and that participation in the program is facilitated by the support of Divisions of General Practice. Copyright © 2009 John Wiley & Sons, Ltd.
A prospective study on the natural course of low‐grade squamous intraepithelial lesions and the presence of HPV16 E2‐, E6‐ and E7‐specific T‐cell responses
Authors: Woo Yin Ling , van den Hende Muriel , Sterling Jane C. , Coleman Nicholas , Crawford Robin A.F. , Kwappenberg Kitty M.C. , Stanley Margaret A. , van der Burg Sjoerd H. 
Published: July 2009

AbstractThis study investigates the clinical course of low grade squamous intraepithelial lesions (LSIL), HPV status and HPV16‐specific immune response in a large prospective study of 125 women with LSIL followed cytologically, virologically and histologically. Women with low‐grade abnormal smears were recruited and followed‐up for one year. Colposcopy, cervical biopsy for histology and brushings for HPV typing was performed at recruitment, 6 months (no biopsy) and upon completion of the study at one year. HPV16‐specific T‐cell responses were analysed by interferon‐γ ELISPOT at entry, 6 and 12 months. Infection with multiple HPV types was detected in 70% of all patients, HPV16 was found in 42% of the patients. LSIL lesions progressed to HSIL in 24%, persisted in 60% and regressed to normal in 16% of the patients. No difference was observed in the clearance rate of infections with single or multiple HPV types among the groups with a different histological outcome. HPV16‐specific type 1 T‐cell responses were detected in only half of the patients with an HPV16+ LSIL, and predominantly reactive to HPV16 E2 and E6. Interestingly, the presence of HPV16 E2‐specific T‐cell responses correlated with absence of progression of HPV16+ lesions (p = 0.005) while the detection of HPV16 E6 specific reactivity was associated with persistence (p = 0.05). This large prospective study showed that the majority of LSIL persisted or progressed within the first year.This was paralleled by immune failure as most of the patients with an HPV16+ LSIL failed to react to peptides of HPV16 E2, E6 or E7.
The metabolic component of cellular refractivity and its importance for optical cytometry
Authors: Tychinsky V. 
Published: July 2009

AbstractInitially, it has been shown that the phase thickness and refractivity (the latter interpreted as the difference of the refractivity indices of an object and surrounding medium) depend on the functional state of mitochondria. The refractivity of various objects decreased in response to energy depletion. This dependence was then demonstrated for other biological objects such as cyanobacteria, chloroplasts and human cells. This general response brought about the hypothesis of a certain “universal” factor that links the variable (or metabolic) component of refractivity with the object's functional state. However, the origin of this phenomenon remains unknown. Our hypothesis is founded on the dependence of polarization of bound water molecules and the activity of metabolic processes. Here, we show the results of measurements of metabolic component of refractivity different bio‐objects (mitochondria, chloroplasts, spores, cancer cells) obtained using the Coherent Phase Microscope “Airyscan”. Estimations indicated high (up to n ≅ 1.41–1.45) values for the equivalent refractive index of structured water in cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Use of capillary electrophoresis with UV detection to compare the phenolic profiles of extra‐virgin olive oils belonging to Spanish and Italian PDOs and their relation to sensorial properties
Authors: Carrasco‐Pancorbo Alegría , Gómez‐Caravaca Ana María , Segura‐Carretero Antonio , Cerretani Lorenzo , Bendini Alessandra , Fernández‐Gutiérrez Alberto 
Published: July 2009

AbstractBACKGROUND: There is much interest in foods that belong to Protected Designations of Origin (PDO) because the quality and other essential and exclusive characteristics are guaranteed because of a particular geographical environment. We have used a capillary electrophoretic method for the simple, rapid and simultaneous characterization and quantification of the polyphenolic fraction of extra‐virgin olive oil from different PDOs (18 compounds in less than 7 min). To demonstrate the usefulness of this method, we have analyzed 16 samples of a Spanish PDO and nine other samples belonging to an Italian PDO (n = 5).RESULTS: In this way, it was possible to compare the phenolic profiles of the oils of different zones of the same PDO, as well as the phenolic profiles of Spanish and Italian extra‐virgin olive oils. Univariate statistics were used for differentiating the oils produced in each PDO. Furthermore, the correlations among several of the phenolic compounds present in the extracts of olive oil and its sensorial properties were checked. decarboxylated oleuropein aglycon (DOA) (b) (peak 6) was the compound more related to the bitterness of the oils, Ac Pin (peak number 4) and the unidentified peak with tmig 4.025 min played an important role in the pungent taste of the oils, and these two latter compounds and the peak 13 seemed to be related to the fruitiness of the oils.CONCLUSIONS: The electrophoretic method described in the current work has the ability to detect and quantify simultaneously 18 phenolic compounds (belonging to five different families) in less than 7 min. This technique could improve the characterization of this polar fraction and determine the geographical origin of olive oils or detect possible ‘PDO markers’. In fact, capillary electrophoresis coupled to statistical analysis enabled discrimination among olive oils belonging to two different PDOs considering eight phenolic compounds present in the extracts, and also identification of the phenolic compounds which could have more influence on several sensory attributes such as bitterness, pungency and fruitiness. Copyright © 2009 Society of Chemical Industry
Nonresponse to a population‐based postdisaster postal questionnaire study
Authors: Hussain Ajmal , Weisaeth Lars , Heir Trond 
Published: July 2009

AbstractWe examined nonparticipation in a 2‐year postdisaster mail survey of Norwegian tourists evacuated from countries affected by the 2004 tsunami. One hundred seventy‐one persons out of a random sample of 330 nonparticipants were telephone interviewed concerning disaster exposure, current posttraumatic stress reactions, and reasons for not participating. Fewer nonparticipants than participants had been in a place directly affected by the tsunami. Nonparticipants reported less perceived threat of death and lower levels of posttraumatic stress reactions. Reasons for not participating were “lack of interest or time” (39.2%), “lack of relevant experiences” (32.2%), and “too personal or emotionally disturbing” (15.2%). Our findings suggest that postdisaster studies may be biased in the direction of more severe disaster exposure and pronounced posttraumatic stress reactions.
Effect of Solvent Characteristics on the Ultrasonic Degradation of Poly(vinylpyrrolidone) Studied by On‐line Monitoring
Authors: Akyüz Ali , Catalgil‐Giz Huceste , Giz Ahmet 
Published: July 2009

AbstractUltrasonic degradation of high molecular weight poly(vinylpyrrolidone) is monitored on‐line, by light scattering. Degradations are performed in water/methanol mixtures of various compositions at room temperature. The evolutions of the weight average molecular weight and the radius of gyration are monitored. The dependence of the radius of gyration on the molecular weight is found. The second virial coefficients (A2) of polymer samples in each solvent are found using Zimm plots. These mixtures are found to be close to theta solvents for poly(vinylpyrrolidone). Degradation rate constants and limit molecular weights are correlated with the radii of gyration and A2 coefficients of the polymer in the solvents studied. It is found that degradation is more effective in better solvents.The dependence of the degradation parameters on solvent characteristics (e.g., the enthalpy of vaporization, solvent viscosity and surface tension) was also investigated and found to be much less significant than for the parameters above.magnified image
Arbitrary visuomotor mapping during object manipulation in Parkinson's disease
Authors: Nowak Dennis A. , Ameli Mitra , Kemper Friederike , Sarfeld Anna‐Sophia , Bensmail Djamel , Konczak Jürgen , Fink Gereon R. 
Published: July 2009

AbstractThe objective of this study is to investigate whether subjects with Parkinson's disease are able to use arbitrary color cues linked to the mass of an object to be lifted allowing for the predictive selection of appropriate grip forces. Fourteen patients with Parkinson's disease used a precision grip to lift two objects of different masses (400 and 600 g) in random order. In a “no cue” condition, a noninformative neutral visual stimulus was presented before each lift, thereby not allowing any judgement about which mass to be lifted. In a “cue” condition an arbitrary color cue provided advance information about which of the two masses patients would have to lift in the subsequent trial. Patients performed the conditions with either hand and by both on and off drugs. In the “no cue” trials patients scaled the predictive grip force output according to the perceived mass of the preceding lift. In the “cue” experiment patients scaled grip force in a predictive manner to mass based on the provided color cues. The ability of arbitrary visuomotor mapping was evident at either hand and not influenced by medication on/off. The precision of arbitrary visuomotor mapping correlated negatively with age, but not with disease duration, severity of motor disability on and off drug, severity of cognitive impairment on and off drug, or the amount of levodopa equivalent daily dosage of dopaminergic drugs. These data imply that Parkinson's disease does not preclude the ability of visuomotor mapping in the grip‐lift task. © 2009 Movement Disorder Society