bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustained Release Solid Dispersions of Pentoxyfylline: Formulation and Optimization
Authors:   Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, India, Kumar Sandeep , Nagpal Manju ,   Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab-140401, Nagpal Kalpana ,   School of Pharmacy, Lovely Professional University, Jalandhar, Punjab, India, Dhingra Gitika Arora ,   NCRD’s Sterling Institute of Pharmacy, Nerul, Navi Mumbai-400706, India
Published: April 2015

Objective: The purpose of the study is to formulate and optimize sustained release solid dispersions of pentoxyfylline using a combination of eudragit polymers and ethyl cellulose. Methods: Solid dispersions were formulated by solvent evaporation method.Preliminary batches were formulated using various drug to polymer ratio; with eudragit S100 and L100 (1:1 to 1:5 ratio), and with ethyl cellulose(1:1 to 1:3 ratio) and evaluated for solubility analysis. Based on results of preliminary batches, Box Behnken design was further applied and three factors (X1- concentration of Eudragit S100, X2- concentration of Eudragit L100, X3- concentration of Ethyl Cellulose) were selected with three levels (+1, 0, -1). Multiple linear regression was applied to generate polynomial equations and statistical evaluation. Prepared solid dispersions were investigated for sustained release properties via in vitro dissolution studies. Fourier transform infrared spectroscopic analysis (FTIR), X-ray diffraction analysis (X-RD), Differential scanning calorimetry (DSC) studies were carried out to evaluate drug polymer interactions. Scanning Electron Microscopy (SEM) analysis of optimized solid dispersion was carried out to evaluate surface morphology of the particles. Results: Batch F5 showed maximum sustained release (65.46% in 24 h) characteristics out of all solid dispersions. DSC studies indicated drug integrity when mixed with the polymeric carriers. FTIR and X-RD studies also ruled out any drug polymer interaction. A change in crystalline habit was observed in solid dispersion particles (F5 batch) as seen in SEM micrographs. Polynomial mathematical model generated using multiple regression analysis was found to be statistically significant (p<0.05). Conclusion: Release retarding effect was found to be dependent on polymer concentration. Therefore, an optimized combination may lead to better sustaining effect.
Dementia: An Overview
Authors:   Department of Pharmacology, ASBASJSM College of Pharmacy, BELA (Ropar) Punjab-140111, India, Bansal Nitin , Parle Milind ,   Department of Pharmacology, ASBASJSM College of Pharmacy, BELA (Ropar) Punjab-140111, India
Published: April 2015

Dementia is a neurodegenerative disorder characterized by progressive and continuous loss of cognitive functions. The neuropsychiatric symptoms include apathy; agitation and depression. As the disorder progresses, the patient gradually becomes dependent on others to perform routine daily activities. Various underlying diseases or disorders are the root cause of the syndrome of dementia. Each of these disorder or disease is characterized by a specific signs and symptoms in combination with a presumed underlying neuropathology. Alzheimer’s disease is the most prevalent cause of dementia. The second most prevalent cause is vascular dementia. In this review, the clinical types, pathophysiology and pharmacotherapy is summarized.
Estimation of Isolated Triterpenoid – Ursolic Acid in Verbena officinalis L. Aerial Parts Using TLC Densitometry
Authors:   Swami Vivekanand College of Pharmacy, Banur-140 601, Patiala, Punjab, India, Kaur Jashanjot , Kumar Deepak ,   Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147 002, Punjab, India, Madaan Reecha ,   Chitkara College of Pharmacy, Chitkara University, Rajpura-140 401, Patiala, Punjab, India, Kumar Suresh ,   Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147 002, Punjab, India
Published: April 2015

Verbena officinalis L. (Vervain; family-Verbenaceae),a traditionally used and medicinally promising plant, has been reported to contain triterpenoids as major class of phytoconstituents. But no work has ever been carried out on V. officinalis to isolate major chemical constituent(s), and to standardize plant material on the basis of isolated constituent(s) using TLC densitometry.The chloroform extract of V. officinalisaerial parts was prepared by extracting properly identified plant in a Soxhlet apparatus.Preliminary phytochemical screening of chloroform extract showed presence of triterpenoids. Column chromatography of chloroform extract using solvent systems viz., hexane:chloroform, chloroform and chloroform:methanol in different concentrationsyielded five fractions (F1- F5). Preliminary phytochemical screening of various fractions of chloroform extract revealed presence of triterpenoids in F2 and F3 fractions. Therefore, these fractions were further subjected to column chromatography. White colored crystals were obtained in SF1 sub-fraction separated from F2and was designated as VOC-1. Structure of VOC-1 was elucidated by IR and NMRspectral studies and was characterized as ursolic acid. Further, ursolic acid was quantified in V. officinalisaerial parts by validated TLC densitometric method. The content of ursolic acid was found to be 0.1580% in V. officinalis aerial parts.The linearity range, correlation coefficient, intra-day precision, inter-day precision, LOD, LOQ and accuracy were found to be 300-1800 ng, 0.997, 1.2% CV, 1.6% CV, 40 ng/spot, 130 ng/spot and 98.27% respectively.
Antihepatotoxic Potential of Citrullus colocynthis Root Extract, Fractions and Isolated Compounds
Authors:   United Institute of Pharmacy, UCER, Allahabad, India, Mukerjee Alok , Mishra Shanti Bhushan ,   United Institute of Pharmacy, UCER, Allahabad, India, Saraf Shubhini ,   Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
Published: April 2015

Medicinal plants are considered to be effective and safe alternative treatment for liver toxicity. The article reveals the hepatoprotective activity of the ethanolic extract of the roots of the Citrullus colocynthis commonly known as INDRYAN using carbon tetrachloride (CCl4) experimental model in albino rats. After receiving significant protection of Ethanolic extract on liver the extract further undergone fractionation into three fractions & the activity was localized in the toluene fraction. These on purification led to the isolation of two pure compounds which were identified as – Cucurbitacin B[1] and Colocynthin [2]. The pure compound shows reduction in enzymatic level viz. (SGOT 68.09%, SGPT 63.64%, ALP 76.81%, BL 68.22%) and (SGOT 71.28%, SGPT 65.24%, ALP 80.68%, BL 54.92%) at 50 mg/ kg dose respectively whereas drug Silymarin showed reduction as (SGOT 79.73%, SGPT 74.26%, ALP 87.88%,BL 82.75% ) at 25 mg/kg dose level. On comparing the obtained data it was observed that the roots of C. colocynthis Sch. exhibited significantly better hepatoprotective activity, thus justifying the traditional claims.
Evaluation of Antioxidant and Anti-Inflammatory Activities of Justicia neesii Ramam Whole Plant Extract
Authors:   Department of Pharmacology, Pydah College of Pharmacy, Kakinada, A.P., India, Sridhar Nimmakayala , Duggirala Suguna Lakshmi ,   Department of Pharmacology, Pydah College of Pharmacy, Kakinada, A.P., India, Puchchakayala Goverdhan ,   Department of Pharmacology, Vaagdevi College of Pharmacy, Hanamkonda, Thelangana, India
Published: April 2015

The plant Justicia neesii is rich in polyphenolic compounds like lignans which can exhibit anti-inflammatory properties. In this study ethanolic extracts of Justicia neesii was screened for elucidating its antioxidant potential using various methods. In all the methods it has shown good antioxidant nature and reducing ability. The IC50 values against DPPH, H2O2, NO and lipid peroxidases were found to be 55.72μg/mL, 133.35μg/mL, 29.65μg/mL and 271.02μg/mL respectively. The total phenolic content in the ethanolic extract was found to be 99.8mg per gram dry plant in gallic acid equivalents. The anti-inflammatory nature of Justicia neesii was tested using carrageenan induced paw edema model in rats. The extract has shown significant inhibition of paw volume at all the three gradient doses of the extract. The percent inhibition of paw volume is correlating with the standard diclofinac sodium. From this study we concluded that Justicia neesii is a plant with potent anti-inflammatory molecules.
Anaerobic degradation of anionic surfactants by indigenous microorganisms from sediments of a tropical polluted river in Brazil
Authors: Silveira Duarte Iolanda Cristina , De França Paula , Yukio Okada Dagoberto , Ferreira do Prado Pierre , Amancio Varesche Maria Bernadete
Published: April 2015

The aim of this study was to evaluate the ability of the microorganisms present in the sediment of the Tietê river to degrade anionic surfactant – linear alkylbenzene sulphonate (LAS)  in the reactor operated in batch sequences under denitrifying conditions.  The reactor was fed with synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose; LAS was added at different stages in concentration of 15 mg/l after 30 mg/L. Reduction in the concentration of co-substrates were evaluated in order to optimize the degradation of surfactant. The results showed that the efficiency of degradation of LAS is directly related to the population of denitrifying bacteria and that the Tietê River sediment can be used as inoculum for the treatment of LAS.  These bacteria were able to degrade LAS regardless of additional carbon source.  The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic load.
Water absorption and dormancy-breaking requirements of physically dormant seeds of Sophora tomentosa L. and Erythrina speciosa Andr. (Fabaceae-Faboideae)
Authors: Luzia Delgado Carolina Maria , Souza de Paula Alexandre , Santos Marisa , Silveira Paulilo Maria Terezinha
Published: April 2015

The physical dormancy of seeds has been poorly studied in species from tropical forests, such as the Atlantic Forest. This study aimed to examine the effect of moderate alternating temperatures on breaking the physical dormancy of seeds, the morphoanatomy and histochemistry of seed coats, and to locate the structure/region responsible for water entrance into the seed, after breaking the physical dormancy of seeds of two woody Fabaceae (subfamily Faboideae) species that occur in the Brazilian Atlantic Forest: Sophora tomentosa and Erythrina speciosa. To assess temperature effect, seeds were incubated in several temperature values that occur in the Atlantic Forest. For morphological and histochemical studies, sections of fixed seeds were subjected to different reagents, and were observed using light or epifluorescence microscopy, to analyze the anatomy and histochemistry of the seed coat. Treated and non-treated seeds were also analyzed using a scanning electron microscope (SEM) to observe the morphology of the seed coat. To localize the specific site of water entrance, the seeds were blocked with glue in different regions and also immersed in ink. In the present work a maximum temperature fluctuation of 15ºC was applied during a period of 20 days and these conditions did not increase the germination of S. tomentosa or E. speciosa. These results may indicate that these seeds require larger fluctuation of temperature than the applied or/and longer period of exposition to the temperature fluctuation. Blocking experiments water inlet combined with SEM analysis of the structures of seed coat for both species showed that besides the lens, the hilum and micropyle are involved in water absorption in seeds scarified with hot water. In seeds of E. speciosa the immersion of scarified seeds into an aniline aqueous solution showed that the solution first entered the seed through the hilum. Both species showed seed morphological and anatomical features for seed coats of the subfamily Faboideae. Lignin and callose were found around all palisade layers and the water impermeability and ecological role of these substances are discussed in the work.
Actividad anti-Toxoplasma de extractos metanólicos de frutos y hojas de Sambucus nigra (Caprifoliaceae)
Authors: Daryani Ahmad , Ebrahimzadeh Mohammad Ali , Sharif Mehdi , Ahmadpour Ehsan , Edalatian Sara , Rahimi Esboei Bahman , Sarvi Shahabeddin
Published: April 2015

Toxoplasma gondii is an obligatory intracellular parasite that infects a wide range of warm-blooded animals and humans. Considering the severity of toxoplasmosis, side effects of current treatments, and the contribution of the ethnopharmacological knowledge for the treatment of parasitic infections, the aim of the present study was to investigate the efficacy of methanolic extracts from the fruits and leaves of Sambucus nigra against tachyzoite of T. gondii. For this, fruits and leaves of S. nigra were collected from Mazandaran province, Iran, were dried under the shade, and powdered using a commercial electrical blender. For extractions, methanol was used as solvent. Virulent RH strain of T. gondii was maintained in mice and macrophages containing tachyzoites were aspirated from the peritoneal cavity. Four concentrations (5, 10, 25 and 50mg/mL) of S. nigra extract were incubated with infected macrophages for 30, 60, 120 and 180 minutes and the viability of the tachyzoites were evaluated by trypan blue staining. Results showed that S. nigra fruit extracts at the concentrations of 5 and 10mg/mL killed 100% of T. gondii tachyzoites after 60 and 120 minutes, respectively; and concentrations of 25 and 50mg/mL killed 100% of the tachyzoites after 30 minutes. Additionally, extract of S. nigra leaves, at the concentrations of 5, 10 and 25mg/mLafter 180 minutes, and concentration of 50mg/mLafter 60 minutes, resulted with the highest efficacy. Our results showed that S. nigra has acceptable efficacy in vitro and the parasiticidal effect of fruit extract was significantly better than leaf extract. However, in vivo efficacy of this extract needs further investigation.
Ecology and management of the invasive lionfish Pterois volitans/miles complex (Perciformes: Scorpaenidae) in Southern Costa Rica
Authors: Sandel Vera , Martínez-Fernández Damián , Wangpraseurt Daniel , Sierra Luis
Published: April 2015

Invasive species alter ecosystem integrity and functioning and are considered one of the major threats to biodiversity on a global scale. The indopacific lionfish (Pterois volitans [Linnaeus, 1758] / miles [Bennet, 1882] complex) is the first non-native marine fish that has established itself in the Western Atlantic. It was first reported in Florida in the 1980s and then spread across the entire Caribbean in subsequent years. In Costa Rica, lionfish were first sighted by the end of 2008 and are now present in all South Caribbean reefs. Lionfish are a major problem for local fisherman by displacing native fish species. The aim of this study was to determine population density, size and diet of lionfish populations at four study sites along the Southern Caribbean coast of Costa Rica. Two of the sites were located inside the National Park Cahuita where regular lionfish removal occurs, whereas the other two study sides do not experiment this kind of management. Total length and wet weight of >450 lionfish individuals were determined between March and June 2011. Three relative metrics of prey quantity (percent number, percent frequency, and percent weight) were compared from ~300 lionfish caught with the polespear in shallow waters (<7m depth). Population density was assessed weekly through visual transect surveys. Our results showed that lionfish preyed mostly upon teleosts and crustaceans. Teleosts dominated lionfish diet in percent frequency (71%) and percent weight (85%), whereas crustaceans had the highest percent number (58%). The top five teleost families of dietary importance were Pomacentridae, Acanthuridae, Blennidae, Labridae and Serranidae. The average total length (±SD) of lionfish was 18.7(±5.7)cm and varied significantly between sites (p<0.001). Mean density of lionfish was 92fish/ha with no significant differences between sites.Smallest fish and lowest densities were found at the two sites inside the National Park Cahuita. Despite management efforts on a regional scale, nationwide efforts are ineffective and lionfish control activities are poorly implemented. We conclude that there is an urgent need to develop an improved institutional framework for local lionfish control that promotes effective coordination among the relevant stakeholders in order to deal with invasive lionfish in Costa Rica.
Reproductive success of Cabralea canjerana (Meliaceae) in Atlantic forest fragments, Brazil
Authors: Franceschinelli Edivani Villaron , Mendes do Carmo Roselaini , De Melo e Silva Neto Carlos , Bastos Gonçalves Bruno , Lima Bergamini Leonardo
Published: April 2015

In Brazil, the Atlantic forest remnants have high biological diversity and a high level of endemism, but very little is known about the reproductive success of native species. Cabralea canjerana is a common tree in the Montane Atlantic forest, and its reproduction is highly dependent on pollinators. In order to contribute with the particular knowledge on this species, we collected data in three fragmented and three continuous forest sites, where the effects of fragmentation on both mutualistic (pollination) and antagonistic (seed predation) interactions were analysed. We determined fruit production and weight of 25 trees per site. The number of seeds and the percentage of predated and aborted seeds were also accessed for seven fruits of 10 trees per site. Pollinator visitation frequencies to flowers were recorded in two forest fragments and in two sites of the continuous forest. Our data showed that plants of C. canjerana produced more fruits (z-value=-8.24; p<0.0001) and seeds per fruit (z-value=-6.58; p=0.002) in the continuous than in the fragmented sites. This was likely due to differences in pollination, because the number of pollinator visits was higher in the continuous forest than in the fragments. Seed abortion (z-value=4.08, p<0.001) and predation (z-value=3.72, p=0.0002), on the other hand, were higher in the fragmented than in the continuous sites. Then, mutualistic and antagonistic interactions were affected by fragmentation, decreasing the reproductive success of the study tree. This study was the first to show a decrease in the reproductive output in forest fragments in an Atlantic forest tree species. This decrease may threaten the population structure and viability of C. canjerana in forest fragments.
Selección del sitio de anidación de individuos de tortuga baula (Dermochelys coriacea, Testudines: Dermochelyidae) en Tortuguero, Costa Caribe de Costa Rica
Authors: Neeman Noga , Wehrtmann Ingo S. , Bolaños Federico
Published: April 2015

Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of dispute. Some authors suggest that a female will tend to randomly scatter her nests to optimize clutch survival at a highly dynamic beach, while others suggest that some site fidelity exists. It is also possible that both strategies exist, depending on the characteristics of each nesting beach, with stable beaches leading to repeating nest site selections and unstable beaches leading to nest scattering. To determine the strategy of the Tortuguero population of D. coriacea, female site preference and repetition were determined by studying whether females repeat their nest zone choices between successive attempts and whether this leads to a correlation in hatching and emergence success of subsequent nests. Nesting data from 1997 to 2008 was used. Perpendicular to the coastline, open sand was preferred in general, regardless of initial choice. This shows a tendency to scatter nests and is consistent with the fact that all vertical zones had a high variability in hatching and emergence success. It is also consistent with nest success not being easily predictable, as shown by the lack of correlation in success of subsequent nesting attempts. Along the coastline, turtles showed a preference for the middle part of the studied section of beach, both at a population level and as a tendency to repeat their initial choice. Interestingly, this zone has the most artificial lights, which leads to slightly lower nest success (though not significantly so) and hatchling disorientation. This finding merits further study for a possibly maladaptive trait and shows the need for increased control of artificial nesting on this beach.

 
Funcionalidad de hongos micorrízicos arbusculares en tres comunidades vegetales de la Reserva Florística Manejada de San Ubaldo-Sabanalamar, Cuba
Authors: Furrazola Eduardo , Covacevich Fernanda , Torres-Arias Yamir , Rodríguez- Rodríguez Raquel M. , Ley-Rivas Juan F. , Izquierdo Katiuska , Fernández-Valle Rigel , Louro Berbara Ricardo Luis
Published: April 2015

Despite the ubiquity and importance of indigenous arbuscular mycorrhizal fungi (AMF) for plant ecosystems; functioning of indigenus mycorrhizal symbiosis (IMS) and related environmental factors at coastal Caribbean ecosystems remains still scarce. In order to determine functionality of IMS under contrasting land uses and wet seasons from Cuba, the influence of the water stress on some AMF functionality parameters from a semi-natural savannah (NS), a recovered savannah (RS) and an agro-ecosystem (AG) from the Managed Floristic Reserve San Ubaldo-Sabanalamar, Pinar del Rio, Cuba were assessed during two-years. Soil and root samples were collected in April and October, during the dry and wet seasons, respectively, in 2008 and 2010. Four plots in each ecosystem were selected, and five soil sub-samples were randomly collected, bulked, mixed homogeneously and used as the composite sample per plot. The host plant root biomass, arbuscular mycorrhizal colonization of the host plant, density of the intraradical and extraradical AMF mycelia, fungal endophyte biomass and AMF spore density were assessed. The host plant root biomass increased in the NS environment during the dry season, and approximately 12.85g root/dm3 dry soil was recorded. The colonization scores were significantly higher in all environments during the wet season of the second year, with means ranging from 79% to 89%. The extraradical mycelia were significantly more abundant in the dry season of the second year in all environments, with a maximum of 279mg/dm3 in the RS ecosystem. The density of AMF spores was highest in the dry season of the second year for the three studied ecosystems. The RS ecosystem hosted 5 670 spores/100g dry soil. In general, the influence of rainfall seasonality on the function of AMF was stronger than the influence of ecosystem management. The root biomass and extraradical mycelia were high in the dry seasons, suggesting strategies to increase the volume of soil for the mutual benefit of the symbionts. The increase in spore density during the dry seasons appears as an adaptation allowing AMF to survive period of water shortage. This study improves our understanding of the adaptative responses of arbuscular mycorrhizal symbiosis to seasonal variations in soil water availability. 
Inversión reproductiva de Aratus pisonii (Decapoda: Sesarmidae): diferencias entre hábitats y análisis de rutas
Authors: López-Sánchez Beatriz , Quintero-Torres Enrique
Published: April 2015

Aratus pisonii is an abundant Neotropical mangrove crab that forages on fresh leaf tissue in the canopy and lives in a wide spectrum of habitats. It presents great plasticity in some aspects of its life history becoming an excellent subject for comparative studies. The purpose of this study was to investigate possible reproductive variations among populations of this crab in mangroves with different levels of structural development, and explore the direct and indirect effects of environmental variables on reproductive investment. The study was conducted during the rainy season of 2003 and 2004, in North Western Venezuela. Fecundity (number of eggs/female), dry weight of egg mass (PSH) and egg quality (C/Neggs) were evaluated in five populations of this species, in mangroves under different environmental conditions (estuarine, marine, hypersaline) and diverse degrees of structural development (arboreal, arbustive, scrub). Reproductive output (Ro) was obtained by the ratio Ro=PSH/dry body weight (PSC); other estimations of Ro were tested: Ro1=PSH/carapace length (CL), Ro2=fecundity/CL. A path analysis was used to explore causal relationships between environmental and morphological variables and reproductive investment (PSH, fecundity). Fecundity ranged from 6 463±831 eggs (Mean±SE) in the hypersaline arbustive mangrove to a maximum of 24 584±2 393 eggs in estuarine arboreal mangrove, which presents the greatest structural development. The reproductive output of females showed significant differences among mangroves, with the highest values of Ro1, Ro2 in the estuarine mangrove females. The results of the path analysis indicated a multicausal effect of morphological and environmental variables; in particular, the salinity showed the greatest influence on fecundity and PSH. The condition of the estuarine mangrove forests with lower salinity and higher structural development involving higher quality of mangrove leaves and a wider range of potential resources, may explain the higher reproductive output of females observed in this habitat.
Longevidad y germinación de semillas de Syagrus romanzoffiana (Arecaceae) y sus implicaciones ecológicas
Authors: Soares Oliveira Túlio Gabriel , Cleiton José Anderson , Monteiro Ribeiro Leonardo , Rocha Faria José Marcio
Published: April 2015

Syagrus romanzoffiana is a palm tree native and widely distributed of South America. The present study investigated the longevity and germination of the buried seeds of this species in an experimental seed bank. Laboratory germination and viability tests were performed for comparison with field results. Pyrenes (seeds enclosed by the endocarp) were buried in a forest fragment edge in July (dry season) in July 2012 and exhumed monthly during one year, for the assessment of water content and percentage of germinated and viable seeds. Germination tests were conducted in a Mangelsdorf-type germinator at 30°C under constant light and the viability was assessed by the tetrazolium test. An additional sample of pyrenes was buried to evaluate the percentage of seedling emergence and survival. Climatic and soil moisture data were recorded. In the laboratory, the pyrenes were stored for one year in a temperature-controlled room at 20ºC and 75% (±10%) relative air humidity to assess changes in the percentage of germination and viability over time. In the field, a reduction in seed viability was observed over the study period, with a total loss of viability of non-germinated seeds at seven months after burial. The maximum germination (close to 26%) was observed in the samples that were exhumed between five and seven months after burial. In the field, seedling emergence did not exceed 10% and seedling mortality was not observed. The percentages of germination and of viable seeds decreased both in burial and stored seeds. The stored seeds maintained viability at up to six months, with marked reduction thereafter. After the germination tests (four months) in the laboratory, all of the remaining seeds were nonviable. The ecological, physiological and reproductive characteristics of the species are discussed, and we concluded that S. romanzoffiana seeds have short longevity after imbibition, and low potential for soil seed bank formation.
Efecto de la temperatura sobre la expresión de genes IFN-1(α), STAT-1 y Mx-1 en alevines de trucha arcoíris Oncorhynchus mykiss (Salmoniformes: Salmonidae) expuestos al el virus de la necrosis pancreática infecciosa (IPNV)
Authors: Arguedas Cortés Donald , Romero Zuñiga Alex P. , Enriquez Sais Ricardo , Martínez Castañeda José S. , Ortega Santana César
Published: April 2015

The infectious pancreatic necrosis (IPNV) is the causative agent of an acute illness well characterized in salmonids worldwide. Clinical signs and mortality rates are dependent on several factors such as the viral dose, the age of the fish, the water temperature, among others. An experimental study was conducted to measure the effect of temperature on the gene expression profile of IFN-1(α), STAT-1 and Mx-1 in rainbow trout fry, exposed to IPNV. Fry (n=198) were exposed at 8, 12 and 16°C, and samples were taken for 21 days to determine the virus titer and gene expression. In the first 11 days the greatest viral titer was recorded at 8°C compared with the values obtained at 12 and 16°C.  At 8°C, there was a significant increase on day 4 of mRNA Mx-1 (t-test, p<0.05), time in which the viral titer began to decrease. Furthermore, as the viral titer increased, STAT-1 and Mx-1 (r=0.91) and (r=0.96) increased, respectively. The animals were able to recover from day 4 from some of the symptoms of IPN. Clinical disease was developed only in fish exposed to 12°C and all died between days 6 and 14, despite the highly significant increase shown in the average expression level of Mx-1, compared with the values recorded at 8°C and 16°C (Tukey, p<0.0001). Additionally, the expression profiles of IFN-1(α) and STAT-1 decreased completely (~0.016) and (~0.020 times) on day 7. The highest expression level of IFN-1(α), occurred at 16°C (Tukey, p<0.0005). Fry exposed at 16°C were normal during the experiment. IFN-1(α) possibly generated a protector effect from day 2 when they showed a significant expression increase compared with the results at 8°C and 12°C (t-student, p<0.0001); however, STAT-1 was not significantly affected by temperature, although the highest average expression value was recorded at 16°C. Our research supports the expression of relevant anti-viral response genes as IFN-1(α), STAT-1 and Mx-1 are physiologically modulated by the water temperature, directly influencing the development of the IPN disease in rainbow trout.
Sodium Metal Production for Energy Storage from Warm Seawater Discharged at Nuclear Power Plant
Authors: Murahara Masataka , Sato Yuji
Published: April 2015

The storage and transportation barriers of hydrogen are cleared by sodium metal “Source of Hydrogen” produced from warm seawater discharged at the nuclear power plant. The warm seawater is electrolyzed to produce sodium hydroxide; which is then subjected to molten-salt electrolysis by surplus power of the plant to produce sodium metal “a hydrogen generator”. The seawater contains salt most after fresh water; which is the raw material of sodium metal and is never drained. The sodium metal is transported to the electric power station in a consumption place, where a large amount of hydrogen is generated immediately by adding water on the sodium metal for power generation. Salt, the raw material of sodium metal, is in the sea over the world, and it is not necessary to worry about the maldistribution and exhaustion.
Phase transition of sigma-CrFe under fast electron irradiation
Authors: Nagase T. , Anada S. , Kobayashi K. , Yasuda H. , Mori H.
Published: April 2015

Preparation of a sigma-CrFe single-phase specimen was achieved by arc melting of pure Fe and Cr, cold rolling, and subsequent annealing at 973 K or 1073 K in vacuum. Cold rolling before annealing is effective for the annealing-induced formation of sigma-CrFe from the bcc solid-solution phase. The phase stability and the structural change from sigma-CrFe to a bcc solid-solution phase under fast electron irradiation were investigated by in situ transmission electron microscope (TEM) observation in the temperature range between 22 K and 473 K by using an ultra-high voltage electron microscope (UHVEM). The phase transition of sigma-CrFe by fast electron irradiation was found to occur at a particular temperature.
Molecular Dynamics Simulation of the Impact of Fission Fragment Energy Deposition on Ion Tracks in Uranium Dioxide
Authors: Wormald Jonathan L. , Hawari Ayman I.
Published: April 2015

In fission based nuclear reactors, uranium dioxide fuel is subject to an intense neutron environment that drives the fission chain reaction. In this process, fission fragments will be produced with an energy reaching 1 MeV/amu. These fragments will initially lose energy through inelastic interactions resulting in excitations of the electronic structure. The excitations subsequently transfer energy to the atomic lattice through electron-phonon (e-p) coupling resulting in a thermal spike which may enhance mobility of fuel atoms. Consequently, the enhanced mobility resulting from fission energy deposition is expected to promote annealing of lattice defects such as ion tracks. Classical molecular dynamics (MD) simulations of uranium dioxide were performed using the LAMMPS code to investigate the effects of fission enhanced mobility on ion tracks formed in the fuel. The MD model was composed of 10×60×60 unit cells, 432000 atoms, and used a Buckingham potential to describe interatomic interactions. A two-temperature model was used to capture the process of fission energy deposition in the electronic subsystem and its transfer to the atomic lattice through e-p coupling. Previous MD simulations demonstrated that fission-enhanced diffusion became more pronounced as the electronic system behavior was varied from metal-like to insulator-like, i.e., increasing the e-p coupling strength. In the present MD simulations, the annealing of an existing ion track (radius nearly 3.0 nm) due to the interaction with 18 keV/nm and 22 keV/nm fission fragments was observed. For a metal-like system (weak e-p coupling), it was found that the track persisted with a radius of nearly 3.0 nm. For an insulator-like system (strong e-p coupling), it was found that the track can be reduced significantly in size approaching a radius of 1.4 nm.
Optimization of bearing structure of ballast leveling machine SPZ-5/UA
Authors: Kostritsya S. A. , Tovt B. M.
Published: April 2015

Purpose. The results of the optimization investigation and the rational projects of the bearing structure of ballast leveling machine SPZ-5/UA are brought in this paper. The necessity of realization of structural optimization of the investigated machine is reasonable. Methodology. The statement of the optimization problem is executed: the beam cross-section square is taken as the objective function; the allowable stresses criterion is taken as the constraint in this problem statement. Findings. The simplified FE-model of structure of machine is worked out. The optimization problem of double-T cross-section is considered as a test case. For this problem we can obtain the analytical and numeral solutions. Originality. The rational designs for the bearing structure of the investigated machine are brought with the increased consumption of material with preservation of durability characteristics. Practical value. The optimization investigation is executed for bearing structure of the ballast leveling machine SPZ-5/UA by the use of the numerical structural optimization procedure. The obtained rational structural projects are compared to the structural projects with standard double-T cross-sections. It is shown that the use of structural projects with standard cross-sections makes it impossible to obtain the better structure as compared to the rational project. As a result the rational structural project of the ballast leveling machine is obtained, which have the sufficient safety factor. The cross-section of the main longitudinal beam of the bearing structure of leveling machine is decreased on 73%.
Problematics of approaches to research of the use safety of ergatic control systems on railway transport
Authors: Kamenyev O. Y.
Published: April 2015

Purpose. Determination of the protective state influence of ergatic control system on a railway transport on their use safety. Making recommendations concerning its accounting for regulations and testing during the development and implementation. Methodology. Research is executed on the base of reliability theory with the use of exponential law of refusals distribution. Findings. It is shown that confirmation of ergatic technical control facilities accordance and trains traffic arrangement to certain functional level of security is not sufficient for guaranteeing of their use safety. It is established that the protective refusal of ergatic control system does not exclude, but only postpones the dangerous condition of the system. Originality. Further development of approach and requirements to research of use safety of ergatic control system on a railway transport are received. Unlike previous they take into account the indexes of not only functional unconcern, but also faultlessness at setting of norms and proof of these systems safety. Practical value. Accounting of protective refusals of technical facilities at tests on their safety application, and also setting of norms of characteristics reliability of control systems by responsible technological processes on a railway transport in accordance with offered approach allows to increase level of their use safety in the exploitation process.
Economic and mathematical justification of train traffic volume distribution on the direction of rail transportation with parallel runnings Znamenka – Odessa
Authors: Logvinova N. A.
Published: April 2015

Purpose. Determination of the economic grounded sizes of motion of freight trains between the areas of railway direction with parallel runnings. A research task is distribution in the operative terms of train work at admission of freight trains between the areas of railway direction with parallel runnings. Methodology. Research is executed with the use of classic methods and methods of the linear programming. Findings. The rational train traffic volume distribution on a railway infrastructure with parallel runnings is presently carried out by an expert method on the basis of information about the before executed volumes of transportations without application of feasibility study. For the task solution of train traffic volume distribution between parallel runnings of railway direction a linear model and methods of the linear programming are used in operative terms. At a design all train traffic volume on a direction part on undistributed train traffic volume – which remaines unchanging for all variants of operative management and distributed – which it is possible to redistribute in some limits between parallel runnings of railway direction. Originality. From the scientific point of view the work is interesting and important by the methods of the linear programming, which allow conducting train traffic volume distribution between parallel runnings in operative terms. Practical value. The practical value of this research is in applying of the described economic and mathematical modeling methods of train traffic volume distribution between parallel runnings on direction Znamenka - Odessa. 10 pairs transmission of freight trains from basic direction Pomoshnaya – Kolosovka – Odessa on parallel direction Pomoshnaya - Kotovsk – Separate is Odessa can be included with the optimum variant.
Use of complex modifiers for improvement of steel R7 quality
Authors: Tatarko J. , Kushnir M. , Markova I. , Ivchenko T.
Published: April 2015

Purpose. Stabilizing of chemical composition and properties, decrease of detrimental impurities concentrations, amount of nonmetallics, grinding down of grain of the R7 wheeled steel by treatment of multicomponent modifiers. Methodology. Probed chemical composition and mechanical properties in accordance with UIC 812-3 and EN 13262 serial melting steel R7 and treated a multicomponent deoxidizers-modifiers are researched. Processing of data is conducted by a regressive-cross-correlation analysis. Findings. Influence of operations of out-of-furnace treatment is set on detrimental impurities concentration. Using of complex modifiers has reduced the concentration of sulfur most effectively. It is shown that in the modified melting variation of both basic alloying elements and admixtures has decreased, homogeneity and dispersion of structure have increased, what mechanical properties of wheels were stabilized due to. Originality. Influence was first set each of the stages of out-of-furnace treatment steel R7 on the detrimental impurities concentration, micro hardness, structure of hard-tempered tests. Dependences of mechanical characteristics were got of the detrimental impurities concentrations. Practical value. By treatment of multicomponent deoxidizers-modifiers, stabilization of chemical composition, sulfur concentration reducing, nonmetallic inclusions amount, grain refining and improving the homogeneity of the structure are achieved, this led to stabilizing and increase of mechanical properties level. It is shown the efficiency of multicomponent deoxidizers-modifiers usage in order to improve quality of steel R7 and reliability of wheels made of it.
Evaluation of quality indicators contacting the surface of the tribological system «Wheel – Rail»
Authors: Kulichenko A. J. , Kuzin N. O. , Vakulenko I. O.
Published: April 2015

Purpose. Modern ideas about the contact interaction of bodies in friction are based on models that take into account the geometric parameters of the surface layers constituting tribosystems. These models provide a high level of adequacy to describe the features of the relief of the surfaces of parts and their impact on the performance characteristics of friction in the elastic stresses. However, the possibility of plastic deformations in the surface layers, particularly before using friction systems, these models do not account for. The aim of this work is the development of new mathematical approaches previously applied accounting strains and their effect on the performance of tribosystems. Methodology. Using the contact mechanics approaches analyzed the influence of preload on contacting a flat rough surfaces using a model based on the assumption of normal distribution of heights and roughness of plastic deformation at the first load. Findings. Analytically determined that under moderate pressure reduction from baseline, the actual contact area is proportional to the pressure in the 2/3 power. Originality. It is found that the contact patch size is proportional to the pressure of the first load. Practical value. It is established that at pressures lower than originally applied to the contact surfaces, the high values of the actual surface contact, the number of patches of actual contact are typical, than for the same pressure at the first load.
Use prospect of the of athermic technologies of metal softening for rolling stock elements
Authors: Vakulenko I. A. , Proydak S. V. , Grischenko N. N.
Published: April 2015

Purpose. The purpose of work is the possibility estimation of аthermic technologies use of cold-deformed metal softening for elements of railway car body and wheel. Methodology. The material for research is the carbon steel of the wheel rim fragment containing 0.55%С, 0.74%Mn, 0.33%Si, and the steel 20. The wheel steel is studied after heat strengthening and cold work after operation. Steel 20 is studied after plastic cold work by rolling. Electric pulse treatment (ET) is carried out on the special equipment. As the property of metal strength the Vickers hardness number is used. The microstructure research is carried out using the light and electronic microscope. Findings. During operation of the rolling stock elements with different strength level origin of damages on metallic surfaces is caused by a simultaneous load action. Taking into account that forming of breakdown sites is largely determined by the state of metal volumes nearby the places of maximal active voltages, the technology development of defect accumulation slowdown or the level of active voltages development allow one to prolong the operating term of rolling stock elements. After electric pulse treatment of the wheel rim fragment the regular changes of metal internal structure corresponded to the hardness changes. The hardness of low carbon steel increases proportional to the increase of the level of cold work by rolling. Alternating bending of the cold-deformed flat is accompanied by strength decrease, which is caused by the metal substructure changes. Originality. The softening process of the cold-worked steel is accompanied by substructure changes, which to a greater extent correspond to the hardening development from the plastic cold-work: dispersion of the dislocation cellular structure, formation of the new sub boundaries and displacement of the formed sub boundaries. Practical value. Introduction of electric pulse treatment in the conditions of railway depots repair base allow one to attain the required level of softening of the cold-worked steel on the wheel thread of railway wheel without heating of metal. The given treatment reduces the metal hardness and prolongs the term of incisors use during the renovation of the rolling profile of the railway wheel
Features of the high frequency power transformer calculation
Authors: Zabarilo D. A.
Published: April 2015

Purpose. The windings of power transformers have low resistance value and a most inductance, which reduces the rate of rise of current in the windings. Therefore, when the estimated amount of current is set one should make sure of the possibility of achieving it. As inductance is characterized by a short-circuit voltage, it is necessary to develop a technique for determining the maximum magnitude of the current in the windings of the transformer according to the short-circuit voltage and operating frequency. Methodology. The classical method of calculation of transient processes to determine the value of the transient current of the transformer windings to achieve purpose is used. Findings. The nature of the transient current in the windings of high-frequency transformer, which is powered by a voltage inverter is investigated and analyzed. Originality. The method for determining the maximum amount of current depending on the short-circuit voltage and frequency of the applied voltage with other set-up parameters was proposed. Practical value. The proposed method allows determining the maximum value of the current in the windings of the high-frequency transformer including its RL-parameters. This will let compare the value of a given current with possible depending on short-circuit voltage and frequency of the applied voltage. Research material may be applied for power transformers design.