bluuebunny/crossref_metadata_2025 huggingface dataset:
Recording Frequency-following Responses to Voice Pitch in Guinea Pigs: Preliminary Results
Authors: Chou Meng-Shih , Lin Chia-Der , Wang Tang-Chuan , Jeng Fuh-Cherng
Published: May 2014

Although scalp-recorded frequency-following response (FFR) to voice pitch has shown great potential to examine pitch processing mechanisms in human participants and animals, few reports have addressed the test-retest reliability of such a response in an animal model. The purpose of this study was to investigate the feasibility and reliability of recording such a response in an animal model and to evaluate the extent to which the response could be separated from background noise. A Chinese monosyllable with a rising pitch was used to elicit the FFR to voice pitch in four guinea pigs. Four objective measures (Root-Mean-Square, Amplitude, Tracking Accuracy, Frequency Error, and Slope Error) were computed from recorded brain waves and were used to examine the phase-locking magnitude and test-retest reliability of the response. Results demonstrated that the animal model produced FFR trends that were repeatable, reliable, and significantly different from responses to the background noise.
Biodegradation of Benzo[a]Pyrene through the use of algae
Authors: Takáčová Alžbeta , Smolinská Miroslava , Ryba Jozef , Mackuľak Tomáš , Jokrllová Jana , Hronec Pavol , Čík Gabriel
Published: May 2014

In this work for disposal of the biologically hard decomposed pollutant Benzo[a]Pyrene (BaP) photooxidation Chlorella kessleri was used. The simulation model system under the different experimental conditions (varying biomass and light intensity) was evaluated. For quantitative analysis of the decrease in BaP, GC/MS technique was used. The highest degradation efficiency was achieved in the case of biomass from the culture of live algae (29%) and light intensity at level of 13.5 W m−2. When the dry biomass was used, degradation under the same conditions was lower because of lack of enzymatic activity in the system.
Determination of 210Po content of vietnamese tobacco samples
Authors: Kovács Tibor , Horváth Maria , Sas Zoltán , Dung Bui , Minh Tran
Published: May 2014

Smoking is one of the leading causes of preventable death. In recent years, numerous countries have initiated the prohibition of smoking in restaurants, workplaces and public spaces. The Vietnamese government intends to follow the precautions against public smoking as well. Over and above the number of some hazardous chemical components found in tobacco, 210Po isotope content could enhance the probability of the development of lung cancer. In this study 14 Vietnamese tobacco products (commercial cigarettes and pipe tobacco) 210Po activity concentration were determined using PIPS semiconductor alpha spectrometry. The results showed that the 210Po activity concentration of the investigated samples varied between 7.40 ± 1.09–128.64 ± 11.22 mBq g−1. The average 210Po content of commercial cigarettes was 15.5 mBq g−1, whilst the average of pipe tobacco was 20.4 mBq g−1. To estimate the risk of inhalation of 210Po isotopes originating as a result of smoking, dose estimations were carried out.
Synthesis, structure and capacitive properties of cobalt hydroxide films on stainless steel substrates
Authors: Barauskienė Ieva , Valatka Eugenijus
Published: May 2014

Cobalt (hydro)oxide films on AISI 304 stainless steel and sintered metal fibre filter Bekipor ST 20AL3 were prepared using electrochemical deposition from neutral cobalt acetate solutions under galvanostatic conditions. Deposited films were structurally characterized using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. All electrochemical measurements were performed in aqueous NaOH solution. Capacitive behavior of different films was evaluated using cyclic voltammetry data. The highest specific capacitance (965 F g−1) was reached when Bekipor ST 20AL3 mesh was used as a support for electroactive substance.
Clinico-pathological studies of Plasmodium falciparum and Plasmodium vivax — malaria in India and Saudi Arabia
Authors: Khan Wajihullah , Zakai Haytham , Umm-e-Asma
Published: May 2014

Malaria is one of the most devastating diseases of tropical countries with clinical manifestations such as anaemia, splenomegaly, thrombocytopenia, hepatomegaly and acute renal failures. In this study, cases of thrombocytopenia and haemoglobinemia were more prominent in subjects infected with Plasmodium falciparum (Welch, 1897) than those with Plasmodium vivax (Grassi et Feletti, 1890). However, anaemia, jaundice, convulsions and acute renal failure were significantly high (3–4 times) in subjects infected with P. falciparum than those infected with P. vivax. The incidence of splenomegaly and neurological sequelae were 2 and 6 times higher in P. falciparum infections compared to the infections of P. vivax. Both in P. vivax and P. falciparum malaria, the cases of splenomegaly, jaundice and neurological sequelae were almost double in children (<10 years) compared to older patients. The liver enzymes were generally in normal range in cases of low and mild infections. However, the AST, ALT, ALP activities and serum bilirubin, creatinine, and the urea content were increased in P. falciparum and P. vivax malaria patients having high parasitaemia, confirming liver dysfunction and renal failures in few cases of severe malaria both in India and Saudi Arabia.
Molecular characterization of muscle-parasitizing didymozoids in marine fishes
Authors: Abe Niichiro , Okamoto Mitsuru , Maehara Tomofumi
Published: May 2014

Classification and identification of muscle-parasitizing didymozoids found in marine fish is difficult because of their novel parasitism and morphology. Recent sequence analysis has helped, but only seven sequences are available. Therefore, the usefulness of molecular methods for differentiation of muscle-parasitizing didymozoids, as well as genetic differences between the muscle and the other site-parasitizing didymozoids are quite unclear. In the present study, six unidentified didymozoid isolates from the trunk muscles of four marine fish species (Diagramma pictum, Plectorhinchus cinctus, Pagrus major and Cypselurus heterurus) were examined genetically using sequence analysis (18S rDNA, 28S rDNA, ITS-2 and coxI). All isolates were placed phylogenetically as a lineage independent of other site-parasitizing didymozoids at 18S rDNA, ITS-2 and coxI. They were grouped into three distinct lineages. The present and the previous unidentified or identified didymozoids from trunk muscles were found to differ clearly for every host species by sequence analysis, suggesting that muscle-parasitizing didymozoids are host-specific. This report is the first describing the molecular characteristics of muscle-parasitizing didymozoids by sequence analysis targeting the nuclear and mitochondrial DNA loci, which is proposed as a superior method for didymozoid differentiation.
Aspects of the morphology of the juvenile life stages of Paradiplozoon ichthyoxanthon Avenant-Oldewage, 2013 (Monogenea: Diplozoidae)
Authors: Avenant-Oldewage Annemariè , Milne Simon
Published: May 2014

There are eight life stages in the life-cycle of Diplozoon paradoxum and limited knowledge of the life-cycle for other diplozoid genera exists. The aim of this study was to record the number of life-stages of Paradiplozoon ichthyoxanthon obtained from, Labeobarbus aeneus and Labeobarbus kimberlyensis, in the Vaal Dam from 2005 to 2007. Six larval life stages and one adult stage of P. ichtyoxanthon were identified from specimens collected in vitro and in situ. In vitro, eggs hatched after 21 days at 18°C. Eggs collected during winter were significantly larger than those laid during spring or summer. Paradiplozoon ichthyoxanthon oncomiracidia have peripheral eyes with pink pigmentation, a tubular anterior bladder-like structure, bicuspid basal pharynx valve and a branched digestive caecum and residual shell material or vitellaria in the caecum. Immature reproductive tissue connected to the ventral sucker and dorsal papillae were noted for the first time in diporpa. Large nervous ganglia and innervation of muscle were observed around the ventral sucker.
On some ultrastructural features of the reproductive system of the monogenean parasite Macrogyrodactylus congolensis from Clarias gariepinus inhabiting the River Nile in Egypt
Authors: Arafa Safaa , El-Naggar Mohammed , Kearn Graham
Published: May 2014

Some organs of the reproductive system of the protogynous monogenean skin parasite Macrogyrodactylus congolensis (Prudhoe, 1957) Yamaguti, 1963 have been studied using transmission electron microscopy. The vesicula seminalis is enclosed by a prominent layer of circular muscle fibres and has inner syncytial protrusions. The penis bulb is a highly muscular organ with prominent radial and circular muscle fibres, a gutter-shaped large spine and 16 small spines. Two syncytial male accessory glands, and a single reservoir for male accessory secretion were identified. The secretory bodies in the male accessory glands and male accessory reservoir have a unique structure. A large oocyte is situated in a chamber, previously referred to as the “ootype” or “egg-cell-forming region” (ECFR), which also contains one or two small undifferentiated cells and vacuolated tissue. Mature spermatozoa were abundant in the receptaculum seminis and dispersed in the vacuolated tissue in the ECFR and appeared to be attached to the membrane of the large oocyte. Mature spermatozoa were also seen in the parenchymal tissue near the chamber containing embryos and even in the tissues of the embryo.
Import of exotic and zoonotic trematodes (Heterophyidae: Centrocestus sp.) in Xiphophorus maculatus: Implications for ornamental fish import control in Europe
Authors: Mehrdana Foojan , Jensen Hannah , Kania Per , Buchmann Kurt
Published: May 2014

Ornamental fish, Xiphophorus maculatus, were imported from Singapore to Denmark for distribution to local aquarists. Importers observed lethargic and erratic swimming patterns among fish and forwarded a total of 30 fish for pathological examination to a university diagnostic service. All fish were diagnosed infected with encysted Centrocestus sp. metacercariae in gills (prevalence of 100% and mean intensity of 454.5 ± 161.9 parasites per fish). Metacercariae were identified by morphological and molecular methods. Cysts (mean length 163.3 ± 13.7 μm and mean width 113.3 ± 10.6 μm) contained a bent metacercaria with an X-shaped excretory bladder. PCR amplification of a rDNA region (5.8S rRNA gene, ITS-2, 28S rRNA gene) and subsequent sequencing confirmed the diagnosis. Metacercariae were found in gill filaments adjacent to the cartilage associated with cartilage hypertrophy, epithelial and mucous cell hyperplasia, clubbing and lamellar fusion. Host cell encapsulation of cysts comprised several layers of leucocytes, chondroblast-like and fibroblast-like cells. The observations raise concerns with regard to veterinary inspection and quarantine procedures. The zoonotic potential of these trematodes and a possible spread of the parasites in natural habitats in Europe should be regarded as a public health issue. So far, several cases of human infections have been reported only in Asia, but the potential intermediate host snail, Melanoides tuberculata, has been recorded in Germany. Accordingly, establishment of the parasite in Europe with climate changes should be considered a risk.
Isospora massardi sp. nov. (Apicomplexa: Eimeriidae) from the white-necked thrush Turdus albicollis (Passeriformes: Turdidae) from Brazil
Authors: Lopes Bruno , Berto Bruno , Luz Hermes , Galvão Gideão , Ferreira Ildemar , Lopes Carlos
Published: May 2014

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) are reported from the white-necked thrush Turdus albicollis Vieillot, 1818, a very common species in South America. Isospora massardi sp. nov. oocysts are subspherical, 18.6 × 17.7 μm, with smooth, bilayered wall, ∼0.9 μm. Micropyle, oocyst residuum are absent, but two polar granules are frequently present. Sporocysts are ovoidal, 14.8 × 9.3 μm. Stieda body is knob-like to rounded and substieda body is rounded. Sporocyst residuum is composed of scattered spherules of different sizes. Sporozoites are vermiform with posterior and anterior refractile bodies and a nucleus. This is the sixth description of an isosporoid coccidium infecting a New World turdid bird.
Confirming Hypoderma tarandi (Diptera: Oestridae) human ophthalmomyiasis by larval DNA barcoding
Authors: Rukke Bjørn , Cholidis Symira , Johnsen Arild , Ottesen Preben
Published: May 2014

DNA barcoding is a practical tool for species identification, when morphological classification of an organism is difficult. Herein we describe the utilisation of this technique in a case of ophthalmomyiasis interna. A 12-year-old boy was infested during a summer holiday in northern Norway, while visiting an area populated with reindeer. Following medical examination, a Diptera larva was surgically removed from the boy’s eye and tentatively identified from its morphological traits as Hypoderma tarandi (L.) (Diptera: Oestridae). Ultimately, DNA barcoding confirmed this impression. The larval cytochrome c oxidase subunit 1 (COI) DNA sequence was matched with both profiles of five adult H. tarandi from the same region where the boy was infested, and other established profiles of H. tarandi in the Barcode of Life Data Systems (BOLD) identification engine.
Parasitic infections detected by FLOTAC in zoo mammals from Warsaw, Poland
Authors: Maesano Gianpaolo , Capasso Michele , Ianniello Davide , Cringoli Giuseppe , Rinaldi Laura
Published: May 2014

The aim of this study was to estimate the occurrence of intestinal parasites in groups of mammals kept in the Warsaw zoological garden (Poland). 71 pools of fecal samples were analyzed using the FLOTAC techniques. 48% of animals were positive and 47% of positivities showed multiple infections. Toxocara cati (71.4%) was found in felines; marsupials were infected with Coccidia (90%). Giardia spp. (24.0%), Blastocystis spp. (12.3%), Iodamoeba spp. (10.0%), Enterobius vermicularis (6.0%) and Entamoeba coli (3.3%) were found in primates. Gastrointestinal strongyles (60.5%) were prevalent in ruminants which resulted positive also to Coccidia (Eimeria spp. = 50.0%), Trichuris spp. (25.0%) and Nematodirus (14.0%). Strongyles (34.0%) were the most frequent parasites in monogastric herbivores, followed by Parascaris equorum (17.0%). None of the animals showed any symptom associated with gastrointestinal parasitic infections. According to our results the need to prevent, diagnose, control, and treat intestinal parasitism trough specific control programs is mandatory for animal welfare in order to limit the spread of parasitic infections in animals and humans.
Host specificity and in vivo infectivities of the mouse coccidian parasites Eimeria krijgsmanni
Authors: Hashimoto Kazuki , Tanaka Tetsuya , Matsubayashi Makoto , Endo Kyoko , Umemiya-Shirafuji Rika , Matsui Toshihiro , Matsuo Tomohide
Published: May 2014

In the present study, infection experiments of E. krijgsmanni using various hosts were conducted to elucidate the host specificity among some animals and the infectivity to mouse strains. According to the results, the infection was not found in most animals, except for rats, in which some oocyst shedding was detected, and there was no significant difference in infectivity among mouse strains. Additionally, oocyst shedding was hardly detectable in a secondary infection to immunocompetent mice, although it was found in immunodeficient mice. These results indicated that only immunocompetent mice could develop adaptive immunity against reinfection by stimuli of the primary infection. Furthermore, the infection experiments were performed with splenic macrophage (Mφ)-depleted mice with a reagent and Beige (Bg) mice known to be a strain of mice with low NK cell activity. No significant effect was found in primary or secondary infections in the Mφ-depleted mice, whereas the mortality rate was clearly increased in Bg mice inoculated with a large number of oocysts. Their oocyst shedding was similar to that of immunocompetent hosts. Taken together, these results suggested that Mφ has only a minor role in the immune response, but the NK cell has an important function in resistance to primary infection of E. krijgsmanni.
A comparison of two different methods for formation of the beta phase in nanocomposites based on vinylidene fluoride-hexafluoropropylene copolymer
Authors: Borisova Lyudmila , Kiryakova Dimitrina , Atanassov Atanas
Published: May 2014

Nanocomposite materials based on vinylidene fluoride-hexafluoropropylene copolymer and organically modified montmorillonite Cloisite®15A were prepared by two different methods: melt mixing and co-precipitation. The changes taking place in crystalline structure, tensile strength, thermal behavior and the formation of piezoelectric b-phase as a result of the polymer system dissolution in dimethyl sulfoxide were studied. The technological specificity of each method has certain effect on the properties of the obtained nanocomposites. The highest content of b-phase — 95 % was achieved by co-precipitation from the solution of vinylidene fluoride-hexafluoropropylene copolymer in dimethyl sulfoxide and 6 mass % content of Cloisite®15A. Despite the common view that the use of solvents and prolonged technological procedure lead to overall higher expenses, the obtained nanocomposites could be promising for the preparation of new piezo-materials.
Pd/GaN(0001) interface properties
Authors: Grodzicki M. , Mazur P. , Zuber S. , Pers J. , Ciszewski A.
Published: May 2014

This report concerns the properties of an interface formed between Pd films deposited onto the surface of (0001)-oriented n-type GaN at room temperature (RT) under ultrahigh vacuum. The surface of clean substrate and the stages of Pd-film growth were characterized in situ by X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), ultraviolet photoelectron spectroscopy (UPS), and low energy electron diffraction (LEED).

As-deposited Pd films are grainy, cover the substrate surface uniformly and reproduce its topography. Electron affinity of the clean n-GaN surface amounts to 3.1 eV. The work function of the Pd-film is equal to 5.3 eV. No chemical interaction has been found at the Pd/GaN interface formed at RT. The Schottky barrier height of the Pd/GaN contact is equal to 1.60 eV.
Study on process development and property evaluation of sol-gel derived magnesia stabilized zirconia minispheres
Authors: Judes J. , Kamaraj V.
Published: May 2014

In order to overcome limitations in the processing parameters of powder compaction method, a novel processing technique based on sol-gel route has been developed to produce near-net-shaped prototype fine zirconia minispheres with required properties that could potentially be used as grinding media. Impact of magnesia concentration and sintering temperature on the final product has been analyzed in detail. Zirconia minispheres have been characterized to establish a correlation between physical, structural and mechanical properties. Sintering temperature, soaking period, heating rate and viscosity of the sol apparently influence the characteristics of the magnesia stabilized zirconia minispheres. The phase identification, density variation, chemical decomposition, functional group specification, surface area, porosity, shrinkage and microstructural features of the dried and sintered final product have been studied. It has been observed that magnesia content, sintering temperature, density and the grain size of the sintered minispheres have a significant impact on the mechanical properties of the final product.
CVD synthesis of graphene nanoplates on MgO support
Authors: Jugade Ravin , Sharma Shalini , Gokhale Suresh
Published: May 2014

Synthesis of graphene directly on MgO has been carried out and the structural properties of the obtained material have been investigated. Few-layered graphene was produced by simple thermal decomposition of methane over MgO powder at 950 °C in a CVD reactor. The samples were purified by 10 N HNO3 treatment, and studied by TEM, Raman spectroscopy, EDAX and SEM. TEM clearly indicated the formation of graphene. EDAX showed that the purified sample contained only carbon and no traces of MgO. The characteristic Raman features of graphene were also seen as D-band at 1316 cm−1, G-band at 1602 cm−1, and a small 2D-band at 2700 cm−1 in the Raman spectra. The strong D-band suggests that the graphene possess large number of boundary defects. The small 2D-band indicates the formation of few-layered graphene.
Massine/Picasso/Parade
Authors: Morris Gay
Published: May 2014

This essay concerns Leonide Massine's choreography for the Ballets Russes production of Parade (1917). The ballet was groundbreaking in its incorporation of Cubist and Futurist innovations and for its vanguard collaborators, which included Erik Satie, Jean Cocteau, and Pablo Picasso. Massine was only twenty-one at the time, and his choreography has often been dismissed as inconsequential. I argue that Massine not only made a major contribution to the collaboration, but that his working methods and approach to choreography owed more to Cubism's reformist tendencies than to Futurism's call for a radical remaking of art. In laying out a path close to Cubism, Massine set western ballet in the direction of the high modernism that would later be epitomized by George Balanchine.
Can the Thermodynamic Hodgkin-Huxley Model of Voltage-Dependent Conductance Extrapolate for Temperature?
Authors: Forrest Michael
Published: May 2014

Hodgkin and Huxley (H-H) fitted their model of voltage-dependent conductances to experimental data using empirical functions of voltage. The thermodynamic H-H model of voltage dependent conductances is more physically plausible, as it constrains and parameterises its empirical fit by assuming that ion channel transition rates depend exponentially on a free energy barrier that in turn, linearly or non-linearly, depends on voltage. The original H-H model contains no explicit temperature terms and requires Q10 factors to describe data at different temperatures. The thermodynamic H-H model does have explicit terms for temperature. Do these endow the model with extrapolation for temperature? We utilised voltage clamp data for a voltage-gated K+ current, recorded at three different temperatures. The thermodynamic H-H model’s free parameters were fitted (Marquardt-Levenberg algorithm) to a data set recorded at one (or more) temperature(s). Then we assessed whether it could describe another data set, recorded at a different temperature, with these same free parameter values and its temperature terms set to the new temperature. We found that it could not.
Using Neighbor Diversity to Detect Fraudsters in Online Auctions
Authors: Lin Jun-Lin , Khomnotai Laksamee
Published: May 2014

Online auctions attract not only legitimate businesses trying to sell their products but also fraudsters wishing to commit fraudulent transactions. Consequently, fraudster detection is crucial to ensure the continued success of online auctions. This paper proposes an approach to detect fraudsters based on the concept of neighbor diversity. The neighbor diversity of an auction account quantifies the diversity of all traders that have transactions with this account. Based on four different features of each trader (i.e., the number of received ratings, the number of cancelled transactions, k-core, and the joined date), four measurements of neighbor diversity are proposed to discern fraudsters from legitimate traders. An experiment is conducted using data gathered from a real world auction website. The results show that, although the use of neighbor diversity on k-core or on the joined date shows little or no improvement in detecting fraudsters, both the neighbor diversity on the number of received ratings and the neighbor diversity on the number of cancelled transactions improve classification accuracy, compared to the state-of-the-art methods that use k-core and center weight.
The Impact of the Prior Density on a Minimum Relative Entropy Density: A Case Study with SPX Option Data
Authors: Neri Cassio , Schneider Lorenz
Published: May 2014

We study the problem of finding probability densities that match given European call option prices. To allow prior information about such a density to be taken into account, we generalise the algorithm presented in Neri and Schneider (Appl. Math. Finance 2013) to find the maximum entropy density of an asset price to the relative entropy case. This is applied to study the impact of the choice of prior density in two market scenarios. In the first scenario, call option prices are prescribed at only a small number of strikes, and we see that the choice of prior, or indeed its omission, yields notably different densities. The second scenario is given by CBOE option price data for S&P500 index options at a large number of strikes. Prior information is now considered to be given by calibrated Heston, Schöbel–Zhu or Variance Gamma models. We find that the resulting digital option prices are essentially the same as those given by the (non-relative) Buchen–Kelly density itself. In other words, in a sufficiently liquid market, the influence of the prior density seems to vanish almost completely. Finally, we study variance swaps and derive a simple formula relating the fair variance swap rate to entropy. Then we show, again, that the prior loses its influence on the fair variance swap rate as the number of strikes increases.
Community Knowledge and Acceptance of Larviciding for Malaria Control in a Rural District of East-Central Tanzania
Authors: Mboera Leonard , Kramer Randall , Miranda Marie , Kilima Stella , Shayo Elizabeth , Lesser Adriane
Published: May 2014

The use of microbial larvicides, a form of larval source management, is a less commonly used malaria control intervention that nonetheless has significant potential as a component of an integrated vector management strategy. We evaluated community acceptability of larviciding in a rural district in east-central Tanzania using data from 962 household surveys, 12 focus group discussions, and 24 in-depth interviews. Most survey respondents trusted in the safety (73.1%) and efficacy of larviciding, both with regards to mosquito control (92.3%) and to reduce malaria infection risk (91.9%). Probing these perceptions using a Likert scale provides a more detailed picture. Focus group participants and key informants were also receptive to larviciding, but stressed the importance of sensitization before its implementation. Overall, 73.4% of survey respondents expressed a willingness to make a nominal household contribution to a larviciding program, a proportion which decreased as the proposed contribution increased. The lower-bound mean willingness to pay is estimated at 2,934 Tanzanian Shillings (approximately US$1.76) per three month period. We present a multivariate probit regression analysis examining factors associated with willingness to pay. Overall, our findings point to a receptive environment in a rural setting in Tanzania for the use of microbial larvicides in malaria control.
Assessment of the Health Impacts of Climate Change in Kiribati
Authors: McIver Lachlan , Woodward Alistair , Davies Seren , Tibwe Tebikau , Iddings Steven
Published: May 2014

Kiribati—a low-lying, resource-poor Pacific atoll nation—is one of the most vulnerable countries in the World to the impacts of climate change, including the likely detrimental effects on human health. We describe the preparation of a climate change and health adaptation plan for Kiribati carried out by the World Health Organization and the Kiribati Ministry of Health and Medical Services, including an assessment of risks to health, sources of vulnerability and suggestions for highest priority adaptation responses. This paper identifies advantages and disadvantages in the process that was followed, lays out a future direction of climate change and health adaptation work in Kiribati, and proposes lessons that may be applicable to other small, developing island nations as they prepare for and adapt to the impacts of climate change on health.
Stimulation of Bone Healing by Sustained Bone Morphogenetic Protein 2 (BMP-2) Delivery
Authors: Faßbender Mirja , Minkwitz Susann , Strobel Catrin , Schmidmaier Gerhard , Wildemann Britt
Published: May 2014

The aim of the study was to investigate the effect of a sustained release of bone morphogenetic protein2 (BMP-2) incorporated in a polymeric implant coating on bone healing. In vitro analysis revealed a sustained, but incomplete BMP-2 release until Day 42. For the in vivo study, the rat tibia osteotomy was stabilized either with control or BMP-2 coated wires, and the healing progress was followed by micro computed tomography (µCT), biomechanical testing and histology at Days 10, 28, 42 and 84. MicroCT showed an accelerated formation of mineralized callus, as well as remodeling and an increase of mineralized/total callus volume (p = 0.021) at Day 42 in the BMP-2 group compared to the control. Histology revealed an increased callus mineralization at Days 42 and 84 (p = 0.006) with reduced cartilage at Day 84 (p = 0.004) in the BMP-2 group. Biomechanical stiffness was significantly higher in the BMP-2 group (p = 0.045) at Day 42. In summary, bone healing was enhanced after sustained BMP-2 application compared to the control. Using the same drug delivery system, but a burst release of BMP-2, a previous published study showed a similar positive effect on bone healing. Distinct differences in the healing outcome might be explained due to the different BMP release kinetics and dosages. However, further studies are necessary to adapt the optimal release profiles to physiological mechanisms.
The Discovery of Potentially Selective Human Neuronal Nitric Oxide Synthase (nNOS) Inhibitors: A Combination of Pharmacophore Modelling, CoMFA, Virtual Screening and Molecular Docking Studies
Authors: Xu Guanhong , Chen Yue , Shen Kun , Wang Xiuzhen , Li Fei , He Yan
Published: May 2014

Neuronal nitric oxide synthase (nNOS) plays an important role in neurotransmission and smooth muscle relaxation. Selective inhibition of nNOS over its other isozymes is highly desirable for the treatment of neurodegenerative diseases to avoid undesirable effects. In this study, we present a workflow for the identification and prioritization of compounds as potentially selective human nNOS inhibitors. Three-dimensional pharmacophore models were constructed based on a set of known nNOS inhibitors. The pharmacophore models were evaluated by Pareto surface and CoMFA (Comparative Molecular Field Analysis) analyses. The best pharmacophore model, which included 7 pharmacophore features, was used as a search query in the SPECS database (SPECS®, Delft, The Netherlands). The hit compounds were further filtered by scoring and docking. Ten hits were identified as potential selective nNOS inhibitors.
Evolving Concepts in the Pathogenesis of NASH: Beyond Steatosis and Inflammation
Authors: Peverill William , Powell Lawrie , Skoien Richard
Published: May 2014

Non-alcoholic steatohepatitis (NASH) is characterised by hepatic steatosis and inflammation and, in some patients, progressive fibrosis leading to cirrhosis. An understanding of the pathogenesis of NASH is still evolving but current evidence suggests multiple metabolic factors critically disrupt homeostasis and induce an inflammatory cascade and ensuing fibrosis. The mechanisms underlying these changes and the complex inter-cellular interactions that mediate fibrogenesis are yet to be fully elucidated. Lipotoxicity, in the setting of excess free fatty acids, obesity, and insulin resistance, appears to be the central driver of cellular injury via oxidative stress. Hepatocyte apoptosis and/or senescence contribute to activation of the inflammasome via a variety of intra- and inter-cellular signalling mechanisms leading to fibrosis. Current evidence suggests that periportal components, including the ductular reaction and expansion of the hepatic progenitor cell compartment, may be involved and that the Th17 response may mediate disease progression. This review aims to provide an overview of the pathogenesis of NASH and summarises the evidence pertaining to key mechanisms implicated in the transition from steatosis and inflammation to fibrosis. Currently there are limited treatments for NASH although an increasing understanding of its pathogenesis will likely improve the development and use of interventions in the future.
Carbonized Micro- and Nanostructures: Can Downsizing Really Help?
Authors: Naraghi Mohammad , Chawla Sneha
Published: May 2014

In this manuscript, we discuss relationships between morphology and mechanical strength of carbonized structures, obtained via pyrolysis of polymeric precursors, across multiple length scales, from carbon fibers (CFs) with diameters of 5–10 µm to submicron thick carbon nanofibers (CNFs). Our research points to radial inhomogeneity, skin–core structure, as a size-dependent feature of polyacrylonitrile-based CFs. This inhomogeneity is a surface effect, caused by suppressed diffusion of oxygen and stabilization byproducts during stabilization through skin. Hence, reducing the precursor diameters from tens of microns to submicron appears as an effective strategy to develop homogeneous carbonized structures. Our research establishes the significance of this downsizing in developing lightweight structural materials by comparing intrinsic strength of radially inhomogeneous CFs with that of radially homogeneous CNF. While experimental studies on the strength of CNFs have targeted randomly oriented turbostratic domains, via continuum modeling, we have estimated that strength of CNFs can reach 14 GPa, when the basal planes of graphitic domains are parallel to nanofiber axis. The CNFs in our model are treated as composites of amorphous carbon (matrix), reinforced with turbostratic domains, and their strength is predicted using Tsai–Hill criterion. The model was calibrated with existing experimental data.
Effect of Receptor Structure and Length on the Wrapping of a Nanoparticle by a Lipid Membrane
Authors: Zhang Haizhen , Wang Ling , Yuan Bing , Yang Kai , Ma Yuqiang
Published: May 2014

Nanoparticles have been considered as a type of powerful tool to deliver drugs and genes into cells for disease diagnosis and therapies. It has been generally accepted that the internalization of nanoparticles into cells is mostly realized by receptor-mediated endocytosis. However, for the influence of structural factors of receptors on endocytosis, this is still largely unknown. In this paper, computer simulations are applied to investigate the effects of structure (i.e., the number of constituent chains of the receptor) and the length of the receptor on the wrapping behavior of nanoparticles by the lipid membrane, which is a key step of receptor-medicated endocytosis. It is found that these structural factors of receptors have strong effects on the nanoparticle’s final interaction configuration with the membrane in the simulations, such as adhering on the membrane surface or being partly or fully wrapped by the membrane. Furthermore, in some cases, the rupture of the lipid membrane occurs. These results are helpful for the understanding of endocytosis and the preparation of advanced nanoscale drug-delivery vectors.
CO2 Capture and Separation Properties in the Ionic Liquid 1-n-Butyl-3-Methylimidazolium Nonafluorobutylsulfonate
Authors: Zhou Lingyun , Fan Jing , Shang Xiaomin
Published: May 2014

Recently, the use of ionic liquids (ILs) for carbon capture and separation processes has gained great interest by many researchers due to the high solubility of CO2 in ILs. In the present work, solubility measurements of CO2 in the novel IL 1-n-butyl-3-methylimidazolium nonafluorobutylsulfonate [C4mim][CF3CF2CF2CF2SO3] were performed with a high-pressure view-cell technique in the temperature range from 293.15 to 343.15 K and pressures up to about 4.2 MPa. For comparison, solubilities of H2, N2, and O2 in the IL were also measured at 323.15 K via the same procedure. The Krichevsky-Kasarnovsky equation was employed to correlate the measured solubility data. Henry’s law constants, enthalpies, and entropies of absorption for CO2 in the IL were also determined and presented. The CO2 solubility in this IL was compared with other ILs sharing the same cation. It was shown that the solubility of CO2 in these ILs follows the sequence: [C4mim][CF3CF2CF2CF2SO3] ≈ [C4mim][Tf2N] > [C4mim][CF3CF2CF2COO] > [C4mim][BF4], and the solubility selectivity of CO2 relative to O2, N2, and H2 in [C4mim][CF3CF2CF2CF2SO3] was 8, 16, and 22, respectively. Furthermore, this IL is regenerable and exhibits good stability. Therefore, the IL reported here would be a promising sorbent for CO2.
Molecular Docking and Fluorescence Characterization of Benzothieno[3,2-d]pyrimidin-4-one Sulphonamide Thio-Derivatives, a Novel Class of Selective Cyclooxygenase-2 Inhibitors
Authors: Barone Mariarita , Pannuzzo Giovanna , Santagati Andrea , Catalfo Alfio , De Guidi Guido , Cardile Venera
Published: May 2014

The aims of this study were: (i) to explore the structure-activity relationship of some new anti-inflammatory benzothieno[3,2-d]pyrimidin-4-one sulphonamide thio-derivatives 1–11; and (ii) to evaluate the possibility of using the most active compounds as fluorescent probes to determine tumours or their progression. Therefore, to know the precise mechanism by which these compounds interact with cyclooxygenase (COX)-2 enzyme, a molecular docking study was carried out; to assess spectroscopic characteristics, their absorption and emission properties were determined. The results demonstrated that some derivatives of benzothieno[3,2-d] pyrimidine exhibit interesting anti-inflammatory properties related to interactions with active sites of COX-2 and are fluorescent. The antipyrine-bearing compound 4 displayed high COX-2 affinity (ΔG = −9.4) and good fluorescent properties (Φfl = 0.032). Thus, some members of this new class of anti-inflammatory may be promising for fluorescence imaging of cancer cells that express the COX-2 enzyme. Further in vitro and in vivo studies are needed to confirm this hypothesis.
Synthesis, Screening and Pharmacokinetic Evaluation of Potential Prodrugs of Bupropion. Part One: In Vitro Development
Authors: O'Byrne Paul , Williams Robert , Walsh John , Gilmer John
Published: May 2014

In general, prodrugs are developed to circumvent deficiencies associated with the absorption, distribution, metabolism, excretion or toxicological (ADMET) profile associated with the active drug. In our study, we select bupropion, a drug with broad pharmacology incorporating dopaminergic, noradrenergic, nicotinic and cytokine modulation properties, but which is rapidly metabolized in vivo. we exploited its carbonyl and secondary amine functionality to facilitate the synthesis of bioprecursor prodrug forms with the sole objective of identifying analogues with enhanced properties over bupropion. A range of analogues were synthesized, ranging from N-methyl, N-benzyl, oximes, enol acetate and ether forms to examples where both functional groups were utilized to form oxadiazine, oxadiazinone, oxazolone and acetylated derivatives. we then developed an in vitro metabolic screen to simulate the human oral delivery route for these analogues. The selection of media in the screens contained a variety of pH, enzymatic and co-factor systems which mimic metabolic in vivo environments that drugs encounter when delivered orally. By coupling our in vitro screening tool to a selective hyphenated technique such as LC-MS, we were able to quickly select potential prodrugs for further in vitro and in vivo development. From the data generated, the N-alkylated bupropion analogues were shown to have the highest potential to act as bioprecursor prodrugs of bupropion.
On-Orbit Geometric Calibration Model and Its Applications for High-Resolution Optical Satellite Imagery
Authors: Wang Mi , Yang Bo , Hu Fen , Zang Xi
Published: May 2014

On-orbit geometric calibration is a key technology to guarantee the geometric quality of high-resolution optical satellite imagery. In this paper, we present an approach for the on-orbit geometric calibration of high-resolution optical satellite imagery, focusing on two core problems: constructing an on-orbit geometric calibration model and proposing a robust calculation method. First, a rigorous geometric imaging model is constructed based on the analysis of the major error sources. Second, we construct an on-orbit geometric calibration model through performing reasonable optimizing and parameter selection of the rigorous geometric imaging model. On this basis, the calibration parameters are partially calculated with a stepwise iterative method by dividing them into two groups: external and internal calibration parameters. Furthermore, to verify the effectiveness of the proposed calibration model and methodology, on-orbit geometric calibration experiments for ZY1-02C panchromatic camera and ZY-3 three-line array camera are conducted using the reference data of the Songshan calibration test site located in the Henan Province, China. The experimental results demonstrate a certain deviation of the on-orbit calibration result from the initial design values of the calibration parameters. Therefore, on-orbit geometric calibration is necessary for optical satellite imagery. On the other hand, by choosing multiple images, which cover different areas and are acquired at different points in time to verify their geometric accuracy before and after calibration, we find that after on-orbit geometric calibration, the geometric accuracy of these images without ground control points is significantly improved. Additionally, due to the effective elimination of the internal distortion of the camera, greater geometric accuracy was achieved with less ground control points than before calibration.
Estimation of the Image Interpretability of ZY-3 Sensor Corrected Panchromatic Nadir Data
Authors: Li Lin , Luo Heng , Zhu Haihong
Published: May 2014

Image quality is important for taking full advantage of satellite data. As a common indicator, the National Imagery Interpretability Scale (NIIRS) is widely used for image quality assessment and provides a comprehensive representation of image quality from the perspective of interpretability. The ZY-3 (Ziyuan-3) satellite is the first civil high resolution mapping satellite in China, which was established in 2012. So far, there has been no reports on adopting NIIRS as the common indicator for the quality assessment of that satellite image data. This lack of a common quality indicator results in a gap between satellite data users around the world and those in China regarding the understanding of the quality and usability of ZY-3 data. To overcome the gap, using the general image-quality equation (GIQE), this study evaluates the ZY-3 sensor-corrected (SC) panchromatic nadir (NAD) data in terms of the NIIRS. In order to solve the uncertainty resulting from the exceeding of the ground sample distance (GSD) of ZY-3 data (2.1 m) in GIQE (less than 2.03 m), eight images are used to establish the relationship between the manually obtained NIIRS and the GIQE predicted NIIRS. An adjusted GIQE is based on the relationship and verified by another five images. Our study demonstrates that the method of using adjusted GIQE for calculating NIIRS can be used for the quality assessment of ZY-3 satellite images and reveals that the NIIRS value of ZY-3 SC NAD data is about 2.79.
Estimating Canopy Nitrogen Content in a Heterogeneous Grassland with Varying Fire and Grazing Treatments: Konza Prairie, Kansas, USA
Authors: Ling Bohua , Goodin Douglas , Mohler Rhett , Laws Angela , Joern Anthony
Published: May 2014

Quantitative, spatially explicit estimates of canopy nitrogen are essential for understanding the structure and function of natural and managed ecosystems. Methods for extracting nitrogen estimates via hyperspectral remote sensing have been an active area of research. Much of this research has been conducted either in the laboratory, or in relatively uniform canopies such as crops. Efforts to assess the feasibility of the use of hyperspectral analysis in heterogeneous canopies with diverse plant species and canopy structures have been less extensive. In this study, we use in situ and aircraft hyperspectral data to assess several empirical methods for extracting canopy nitrogen from a tallgrass prairie with varying fire and grazing treatments. The remote sensing data were collected four times between May and September in 2011, and were then coupled with the field-measured leaf nitrogen levels for empirical modeling of canopy nitrogen content based on first derivatives, continuum-removed reflectance and ratio-based indices in the 562–600 nm range. Results indicated that the best-performing model type varied between in situ and aircraft data in different months. However, models from the pooled samples over the growing season with acceptable accuracy suggested that these methods are robust with respect to canopy heterogeneity across spatial and temporal scales.
Shallow-Water Benthic Identification Using Multispectral Satellite Imagery: Investigation on the Effects of Improving Noise Correction Method and Spectral Cover
Authors: Manessa Masita , Kanno Ariyo , Sekine Masahiko , Ampou Eghbert , Widagti Nuryani , As-syakur Abd.
Published: May 2014

Lyzenga’s method is used widely for radiative transfer analysis because of its simplicity of application to cases of shallow-water coral reef ecosystems with limited information of water properties. WorldView-2 imagery has been used previously to study bottom-type identification in shallow-water coral reef habitats. However, this is the first time WorldView-2 imagery has been applied to bottom-type identification using Lyzenga’s method. This research applied both of Lyzenga’s methods: the original from 1981 and the one from 2006 with improved noise correction that uses the near-infrared (NIR) band. The objectives of this study are to examine whether the utilization of NIR bands in the correction of atmospheric and sea-surface scattering improves the accuracy of bottom classification, and whether increasing the number of visible bands also improves accuracy. Firstly, it has been determined that the improved 2006 correction method, which uses NIR bands, is only more accurate than the original 1981 correction method in the case of three visible bands. When applying six bands, the accuracy of the 1981 correction method is better than that of the 2006 correction method. Secondly, the increased number of visible bands, when applied to Lyzenga’s empirical radiative transfer model, improves the accuracy of bottom classification significantly.