bluuebunny/crossref_metadata_2025_split huggingface dataset:
Near infrared ex-vivo bovine and computer model thresholds for laser-induced retinal damage
Authors: Schulmeister Karl , Ullah Rahat , Jean Mathieu 
Published: May 2012

AbstractThresholds for thermal damage of the retina were determined with excised bovine eyes and a computer model for 1090 nm laser radiation in the applicable pulse duration regime and for varying retinal laser spot diameters. The thresholds compare well with available rhesus monkey data, further validating the models for absolute threshold predictions and parameter studies including in the near infrared (NIR) range up to about 1340 nm. The variation of the spot size dependence for different pulse durations that was found in an earlier study for the wavelength of 532 nm was confirmed, which supports the proposed amendment of ICNIRP, ANSI and IEC laser and incoherent optical radiation exposure limits. The earlier conclusion that the damage mechanism at threshold determined 24 h and 1 h after exposure for the non-human primate (NHP) model is retinal pigment epithelium (RPE) cell damage and not thermal coagulation of the sensory retina was confirmed. The data in the NIR range indicate that scattering within the RPE and choroid does not significantly enlarge the effective spot size, and that the rhesus monkey minimal spot
High-resolution two-photon imaging of HE-stained samples in dermatohistopathology – A pilot study on skin tumours
Authors: Göppner Daniela , Mechow Norma , Liebscher Julia , Thiel Erik , Seewald Gunter , Buchholz Anja , Gollnick Harald , Philipp Carsten M. , Schönborn Karl-Heinz 
Published: May 2012

AbstractNon-invasive two-photon microscopy (TPM) provides a new technique which could become in the future a substitute for hematoxylin and eosin (HE) staining of tissue sections of the epidermis and upper and middle dermis as well. High-resolution imaging, in combination with false-colour representation, allows an accurate reproduction of standard microscopy. The vertical skin viewing of epidermis and upper dermis by means of TPM allows for a new histopathological supportive technique, especially in non-melanoma skin cancer such as squamous cell carcinoma and basal cell carcinoma. If it could be used on fresh tissue samples, it could provide an alternative method to Mohs 3D histology, even though the definitive criteria for melanocytic tumours have not yet been sufficiently evaluated.
Effects of Substrate Pre-deposition Annealing and Deposition Parameters on the Properties of RF Sputter-deposited ZnO Films
Authors: Oder T. N. , McMaster M. , Smith A. , Velpukonda N. , Sternagle D. 
Published: May 2012

ABSTRACTZinc Oxide thin films were deposited on sapphire substrates by radio frequency (RF) magnetron sputtering from an ultra-high purity ZnO solid target. The ZnO films were deposited on sapphire substrates heated in oxygen and/or in vacuum prior to deposition. Additional parameters investigated included the substrate temperature varied from 25 °C to 600 °C, the deposition gas pressure varied from 5 mTorr to 40 mTorr and the gas flow rate varied from 5 to 30 standard cubic centimeter per minute (sccm). The resulting films were annealed using a rapid thermal processor in N2gas at 900 °C for 5 min. Analyses carried out using photoluminescence spectroscopy (PL) and X-ray diffraction (XRD) measurements indicate that films deposited at 300 °C using Ar:O2(1:1) had the best optical and microstructure qualities. Pre-heating the sapphire substrate in oxygen prior to deposition was found to create a smoother sapphire surface, and this produced a ZnO film with greatly improved qualities. This film had a luminescence peak at 3.362 eV with a full-width-half maximum (FWHM) value of 15.3 meV when measured at 11 K. The XRD 2θ-scans had peaks at 34.4° with the best FWHM value of only 0.10°. Production of high quality ZnO materials is a necessary step towards realizing highly conductive p-type doped ZnO materials which is currently a major goal in research efforts on ZnO.
Optical Transport Properties of Oriented Isotactic Polypropylene and Carbon Nanotube Nanocomposite Thin Films
Authors: Sarkar Sabyasachi , Kalakonda Parvathalu , Georgiev Georgi Y. , Iannacchione Germano S. , Cebe Peggy 
Published: May 2012

ABSTRACTOptical transport through Isotactic Polypropylene (iPP) and multiwall carbon nanotubes (MWCNTs) nanocomposite thin films is important to many applications where optical transmission or polarization are used. Especially interesting is the case where the optical properties are anisotropic as in oriented thin films and the optical transport is different in the direction of orientation and perpendicular to it. Changing the orientation of the film or the polarization of the light can change the way in which the nanocomposite film interacts with light. Our polymer of choice, Isotactic Polypropylene, is one of the most widely used polymers which will increase the applicability of our results. We blended iPP with different concentration of carbon nanotubes (CNTs): 1%, 2% and 5% and oriented the thin film samples using melt-shear at 200°C and 1Hz in a Linkam microscope sharing hot stage. We measured that the index of refraction of the nanocomposites slightly decreased when CNTs are added and that when nanocomposites were shear-oriented at low loading of CNTs the index of refraction showed small difference in directions parallel and perpendicular to the direction of orientation. The extinction coefficient increased therefore it’s tuning in the nanocomposite films by the content of the carbon nanotubes can help devise new materials with the desired values of this property.
Proton Exchange Membrane Synthesized by Pore-Filling Polymerization Technique
Authors: Tay Siok Wei , Liu Zhaolin , Hong Liang 
Published: May 2012

ABSTRACTProton exchange membrane with interconnected H+-transfer channels in submicron scale has been synthesized by means of pore filling polymerization. Polysulfone (PSU) membrane containing densely distributed pores is synthesized using the phase inversion approach. The membrane is then filled up with a designed formula consisting of monomers (e.g. 2-acrylamido-2-methylpropane sulphonic acid and N, N’-Methylenebisacrylamide) and a binary solvent. It is undertaken through solution diffusion of the monomer formula into the pores impregnated with the bore liquid. When the PSU matrix loaded with monomers is subjected to polymerization, a uniform distribution of interconnected H+-transfer channels is realized. This special membrane structure gives rise to a maximum ionic exchange capacity of 2.43 meq/g and the highest proton conductivity of 0.2 S/cm. Compared to the commercial Nafion® membrane, the pore-filled membrane significantly enhances the power output of H2-PEM fuel cell.
Theory of volume transitions in polyelectrolyte gels
Authors: Mitra Mithun K. , Muthukumar M. 
Published: May 2012

ABSTRACTWe present the key assumptions and results of a newly developed theory in order to account for the self-consistent cascade effects of counterion condensation and volume collapse of polyeletrolyte gels. In the present theory, the role of the specificity and valency of counterions on the volume transitions are also treated. These features and the fluctuations of monomer concentration and local electrolyte charge density are included on top of the familiar features of the Flory-Huggins theory and the classical rubber elasticity theory in the previously used Flory-Dusek-Patterson-Tanaka theory of polyelectrolyte gels. We have computed the swelling equilibria by satisfying the multicomponent nature of the system and the Donnan equilibria. A few major effects are illustrated in terms of the dependence of volume transition on the solvent quality, temperature, salt concentration, valency and specificity of the counterion, and polymer charge density. Criteria for the emergence of a reentrant volume transition are also derived.
ATOMISTIC SIMULATION OF DISSIPATIVE CHARGE CARRIER DYNAMICS FOR PHOTOCATALYSIS
Authors: Inerbaev Talgat M. , Kilin Dmitri S. , Hoefelmeyer James 
Published: May 2012

ABSTRACTPhoto-excitation of high surface area semiconductor nanorods decorated with surface catalyst particles are investigated. DFT-based simulation is applied to the charge transfer dynamics at the interface of the supported nanocatalyst by modeling dynamics of photo-excitations. The modeling is performed by reduced density matrix method in the basis of Kohn-Sham orbitals. The energy of photo-excitation is dissipating due to interaction with lattice vibrations, treated through non-adiabatic coupling as the electron/hole pair relaxes to the conduction / valence band edges. The methodology is applied to TiO2 nanorod modeled as a periodic anatase (100) slab functionalized by minimalistic nano-clusters or doping. Simulations of these models demonstrate the formation of charge transfer state in both time and frequency domain. Computed charge dynamics leads to creation of positively charged areas on the nanorod surface that is an important prerequisite for oxidation catalysis. Our computation identifies optimal composition and morphology of nanocatalyst for such applications as water splitting for hydrogen production or solar cells.
Network Formation and Electrical Conduction in Carbon Nanotube Modified Polydimethylsiloxane
Authors: Cattin Cyrill , Hubert Pascal 
Published: May 2012

ABSTRACTThe focus of this research is on network formation and electrical conduction in carbon nanotube polydimethylsiloxane nanocomposites. Carbon nanotube network formation prior to and during polymerization was monitored by means of simultaneous electrical and rheological characterization. Processing induced network formation at filler concentrations below statistical percolation was observed, and both the electrical resistivity and the voltage dependence of the sample resistance were found to increase with the degree of polymerization, indicating carbon nanotube separation during polymer cure. Electron tunnelling through insulating polymer layers was identified as the main conduction mechanism. Information about the final network structure and further details about electrical conduction were obtained from the piezoresistive response of the material. Electron tunnelling was found to be dominant at filler concentrations close to the percolation threshold. With increasing filler concentration a densification of the carbon nanotube network was observed, and the resistance behaviour at high filler content was better described by the behaviour of a parallel circuit.
Self-Assembled Gels from Biological and Synthetic Polyelectrolytes.
Authors: Calvert Paul , Limem Skander , McCallum Don , Wallace Gordon , Panhuis Marc in het 
Published: May 2012

ABSTRACTInkjet printing of alternate layers of anionic and cationic polyelectrolytes allows organized gels to form with structures similar to those made by layer--by-layer dipping methods but very much faster. Structures of gels formed using slow and fast inkjet printing systems are compared using elemental analysis, swelling and diffusion kinetics as characterization methods. After printing and washing, most sodium or chloride counter-ions are last from the gel, leave only the polymer complex. The swelling properties of the printed and washed gel depend on the deposition rate and on the ratio of the two polymers as originally printed. The synthetic polyelectrolytes reported here can be compared with biological polyelectrolytes reported earlier by us.
Diversity and Abundance of Ectoparasitic Blow FliesProtocalliphora(Diptera: Calliphoridae) and theirNasonia(Hymenoptera: Pteromalidae) Parasitoids in Tree Swallow Nests within Agricultural Lands of Southern Québec, Canada
Authors: Daoust S P , Savage J , Whitworth T L , Bélisle M , Brodeur J 
Published: May 2012

AbstractWe described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera: Calliphoridae) and their Nasonia (Ashmead) (Hymenoptera: Pteromalidae) parasitoids collected from tree swallow, Tachycineta bicolor (Vieillot), nests in southern Québec, Canada, in 2008 and 2009. The prevalence of nest infestation by Protocalliphora was 70.8% in 2008 and 34.6% in 2009. The average parasitic burden of Protocalliphora spp. was estimated at 5.53 (±5.61 SD) pupae per nestling for 2008 and 4.66 (±9.31 SD) pupae per nestling for 2009. The percentage of nests containing Protocalliphora pupae parasitized by Nasonia spp. was of 85.3% in 2008 and 67.2% in 2009. Three species of Protocalliphora were collected—Protocalliphora sialia Shannon & Dobroscky, Protocalliphora bennetti Whitworth, and Protocalliphora metallica (Townsend)—and two species of Nasonia, Nasonia vitripennis (Walker) and Nasonia giraulti Darling. This is the first record of P. bennetti and N. giraulti in the province of Québec. Our findings provide further evidence for observation made previously that altricial bird nests are more frequently and more heavily infested by blow flies in western than in eastern North America. Our data also suggest that more than a quarter of the tree swallow within the study area are exposed to high levels of ectoparasitism that could negatively affect their health.
Seasonal Cold Tolerance of Chilo suppressalis (Lepidoptera: Pyralidae)
Authors: Lu Ming-Xing , Liu Zhong-Xian , Wang Xun , Du Yu-Zhou 
Published: May 2012

Abstract
The Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is an important, widely distributed pest of rice, Oryza sativa L., in China. However, information is lacking about postdiapause levels of cold resistance during periods of normal development. Our results indicate that field larvae of C. suppressalis collected in March 2010 had very low survival if exposed to -21°C. When exposed to test temperatures for 1 h, the LTemp50 and LTemp90 values of C. suppressalis were -18.8 and -20.8°C, respectively. LTime50 and LTime90 values at -16°C (5.1 and 9.6 h) were unexpectedly lower than those at -17°C (7.1 and 18.3 h). For larvae collected in August, mortality at -18°C (with 2-h exposure) was 98% but was only 8% at -6°C (2-h exposure). Maximum cold tolerance of C. suppressalis was observed in larvae collected on 15 January 2011. These data suggest that cold hardiness in C. suppressalis is independent of the diapause state of the insect.
The Effect of Ants on the Population Dynamics of a Protective Symbiont of Aphids, Hamiltonella defensa
Authors: Erickson Daniel M , Wood Elizabeth A , Oliver Kerry M , Billick Ian , Abbot Patrick 
Published: May 2012

Abstract
Mutualists that provide redundant services to the same organism have been shown both to coexist and compete for access to the partner. Aphids, for example, are known to receive protection against natural enemies from both heritable bacterial symbionts as well as ants, which tend aphids in exchange for sugary honeydew excretions. Little is known, however, about how ant attendance might influence interactions between aphids and their protective bacteria. Assuming costs to infection, we hypothesized that protective symbiont prevalence would decrease in the presence of ants, because of duplication of services. We surveyed natural aphid populations and found Hamiltonella defensa, a bacterium that provides resistance to aphids against parasitoid wasps in laboratory settings, among several aphid species, including Obtusicauda frigidae (Oestlund 1886). We excluded ants from protecting O. frigidae aggregations and measured the effect of ant absence on the frequency of parasitoid attack and H. defensa infection in aphid groups. Ant presence did not reduce H. defensa frequency in aphids, likely because ants and H. defensa did not significantly lower parasitoid wasp attack rates. Metabolic costs likely control H. defensa prevalence more than the effect of ant-tending.
The Effect of Implicit and Explicit Practice in the Development of Decision Making in Volleyball Serving
Authors: Lola Afrodite C. , Tzetzis George C. , Zetou Helen 
Published: May 2012

This experiment investigated the effect of explicit, implicit, and sequential learning (implicit-explicit) on the acquisition and retention of decision-making skill in volleyball. The participants were 60 female novices, aged 10–12 years. The experimental groups followed three different methods of training: (a) explicit practice for development of declarative knowledge, (b) implicit practice for the development of procedural knowledge, (c) sequential practice (implicit first and then explicit), and (d) no practice (only measurements) - a control group. At pre-testing, post-testing, and retention testing there were measurements of the participants’ decision-making response time and accuracy. Analyses indicated that all experimental groups improved over time while the control group did not. The sequential group was faster and more accurate than the implicit group, and the latter was faster and more accurate than the explicit group. The sequential group outperformed implicit and explicit groups on both speed and accuracy. It seems that both explicit and implicit processes, when they take place in sequence, interact positively, and this method improves speed and accuracy of decision making rather than when each mode of learning (implicit or explicit) occurs separately. If the role of working memory is reduced at the early stages of learning, the accumulation of declarative knowledge (explicit learning) may benefit from accumulation of procedural knowledge and enhance decision-making skill.
The relationship between daily Internet use time and school performance in Korean adolescents
Authors: Kim Dong-Hyun , So Wi-Young 
Published: May 2012

Abstract
This study investigates whether daily Internet use time is related to the school performance of Korean adolescents. We therefore analyzed raw data from the 2009 Korea Youth Risk Behavior Web-based Survey-V (KYRBWS-V), in which 75,066 students from the middle-school first grade to the high-school third grade participated. We assessed the association between daily Internet use time and school performance by using multivariate logistic regression analysis adjusted for age, body mass index, education level of parents, and economic status of the family. For boys, the odds ratio (OR) [95% confidence interval (CI)] for recording ≥ average school performance and daily time spent on Internet use was 1.876 (1.752–2.008, p < 0.001) for ≤1 hour, 1.564 (1.467–1.667, p < 0.001) for >1–≤2 hours, 1.158 (1.079–1.242, p < 0.001) for >2–≤3 hours, and 0.759 (0.695–0.828, p < 0.001) for over 4 hours, when compared to those who never used the Internet. For girls, the OR (95% CI) for recording ≥ average school performance and daily Internet use time was 1.729 (1.607–1.860, p < 0.001) for ≤1 hour, 1.503 (1.399–1.616, p < 0.001) for >1–≤2 hours, 1.193 (1.100–1.293, p < 0.001) for >2–≤3 hours, and 0.809 (0.725–0.903, p < 0.001) for over 4 hours, when compared to those who never used the Internet. It was concluded that Korean adolescents who spend ≤3 hours per day on the Internet are predisposed to an increase in performance levels at school, whereas those who spend over 4 hours per day on the Internet are predisposed to a decrease in school performance levels.
Statistical interpretation of medical data of patients with alcohol abuse
Authors: Bardarov Ventzislav , Simeonova Pavlina , Neikova Ludmila , Bardarov Krum , Simeonov Vasil , Tsakovski Stefan , Kanev Kamen 
Published: May 2012

Abstract
An attempt is made to assess a set of biochemical, kinetic and anthropometric data for patients suffering from alcohol abuse (alcoholics) and healthy patients (non-alcoholics). The main goal is to identify the data set structure, finding groups of similarity among the clinical parameters or among the patients. Multivariate statistical methods (cluster analysis and principal components analysis) were used to assess the data collection. Several significant patterns of related parameters were found to be representative of the role of the liver function, kinetic and anthropometric indicators (conditionally named “liver function factor”, “ethanol metabolism factor”, “body weight factor”, and “acetaldehyde metabolic factor”). An effort is made to connect the role of kinetic parameters for acetaldehyde metabolism with biochemical, ethanol kinetic and anthropometric data in parallel.
Parasite fauna of rodents (Murinae) from El Hierro (Canary Islands, Spain): a multidisciplinary approach
Authors: Feliu Carlos , López Mercedes , Gómez María , Torres Jordi , Sánchez Santiago , Miquel Jordi , Abreu-Acosta Néstor , Segovia Juan , Martín-Alonso Aarón , Montoliu Isabel , Villa Mercedes , Fernández-Álvarez Ángela , Bakhoum Abdoulaye , Valladares Basilio , Orós Jorge , Foronda Pilar 
Published: May 2012

AbstractThe parasite fauna (protozoa, helminths and insects) of the two most widespread Murinae rodents in El Hierro (Canary Islands, Spain), the black rat (Rattus rattus) and the house mouse (Mus musculus domesticus) was studied. Faunistic, ecological, ecotoxicological data, as well as information on the biology of some nematode parasites of R. rattus are provided. The present work is unprecedented in the Canary Islands, and provides the first data on the parasite biodiversity in Murinae from the archipelago. Concerning to parasitofaunas stands out: a) impoverishment of biodiversity of helminths respect of which have the same hosts in other islands; b) increasing the number of species of Siphonaptera, even compared with flea species that parasitize the same hosts from continental biotopes.
Advanced stages of embryonic development and cotylocidial morphogenesis in the intrauterine eggs of Aspidogaster limacoides Diesing, 1835 (Aspidogastrea), with comments on their phylogenetic implications
Authors: Świderski Zdzisław , Poddubnaya Larisa , Gibson David , Młocicki Daniel 
Published: May 2012

AbstractUltrastructural aspects of the advanced embryonic development and cotylocidial morphogenesis of the aspidogastrean Aspidogaster limacoides are described. The posterior or distal regions of the uterus are filled with eggs containing larvae at advanced stages of morphogenesis and fully-formed cotylocidia. Various stages and organs of this larva are described in detail, including the aspects of the developing and fully-differentiated cotylocidium, the body wall (tegument and musculature), glandular regions and the protonephridial excretory system. Blastomere multiplication by means of mitotic divisions takes place simultaneously with the degeneration or apoptosis of some micromeres; this frequently observed characteristic is compared and discussed in relation to corresponding reports for other neodermatans. During the advanced stages of the embryonic development of A. limacoides, the vitelline syncytium disappears and the size of the embryo increases rapidly. Evident polarization of the differentiating larva was observed; towards one pole of the egg, cytodifferentiation of the mouth, surrounded by the oral sucker and cephalic glands, takes place, whereas, towards the opposite pole, differentiation of the posterior sucker (incipient ventral disc) occurs. The oral and posterior suckers are formed from numerous embryonic cells which have differentiated into myocytes. The central part of the oral sucker undergoes invagination and forms the future pharynx and intestine. Fully-developed cotylocidia of A. limacoides have a neodermatan type of tegument, flame cells and two types of glandular structures. These results suggest a sister relationship between the Aspidogastrea and the Digenea, although the systematic position of aspidogastreans in relation to other platyhelminth taxa remains somewhat equivocal.
Magnetic chains formed from tetra-coordinate Co(II) complexes
Authors: Idešicová Monika , Krutošíková Alžbeta , Mrázová Viera , Boča Roman 
Published: May 2012

AbstractTwo tetra-coordinate Co(II) complexes, [CoCl2(bzfupy)2] and [CoCl2(p-tol)2] with N-donor ligands, are apparently mononuclear systems. The magnetic susceptibility at low temperature attains a maximum which is a fingerprint of the exchange interaction. The exchange coupling constant fitted to a model of 1D-magnetic chain yields J/hc = −0.50 cm−1 and −0.57 cm−1, respectively. The magnetic interaction is mediated by the π-π stacking in the first complex, and the short Cl…Cl contacts in the second.