Study of microstructure of oriented PET fibres exposed to supercritical carbon dioxide

Samples of partially oriented yarn (POY) PET fibers were uniaxially drawn at temperatures below, near, and above the glass transition temperature at a constant draw ratio before exposure to supercritical carbon dioxide (scCO₂) in the presence of tension at a temperature of 80 °C and a pressure of 220 bar. The effects of drawing temperature and scCO₂ exposure on structural changes and on mesomorphic transitions, in particular, were investigated using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and birefringence and density measurements. A good correlation was obtained among the results obtained from various techniques. Results indicated that the development of a transient mesophase structure depended strongly on process temperature. By drawing PET fibers in the samples at temperatures below the glass transition (cold-drawing), a mesophase structure developed in which the highly extended chains played a key role in structural changes incurred. Meanwhile, exposure to scCO₂ led to the plasticization of the samples accompanied by their reduced glass transition and cold crystallization temperatures. This process also gave rise to the appearance of a second melting peak at about 135 °C that is related to the melting of imperfect and thin crystals, thereby inducing structural changes in the treated fibers. In the case of samples subjected to cold drawing and to scCO₂ exposure, the transformation of the mesophase structure into the crystalline phase was found to be strongly affected by scCO₂ exposure, while this same effect was negligible in the case of hot drawn samples.     

Epidemiological aspects of Pediculosis capitis and treatment evaluation in primary-school children in Iran

This study was undertaken to assess the prevalence of and epidemiological factors associated with, head lice infections in Iranian primary schools in 2006 and evaluate data on the therapeutic efficacy of lindane shampoo. A total of 40586 children (19774 boys (48.72%) and 20812 girls (51.28%)] from 198 Governmentprimary schools in Kerman, were screened for head lice between March and June 2006. The diagnosis of head lice infestation was confirmed by clinical inspection of scalp and hair for the presence of adult lice nymphal stage, or eggs (nit) by line-toothed head lice comb. All children infested with lice were treated with lindane shampoo (1% gamma benzene hexachloride). The overall prevalence of head lice infestation was 1.8%. The prevalence of infestation was significantly higher in girls (2.9%) than in boys (0.6%) (p = 0.000). The infestation rate was greater among pupils who were living in rural areas (4.6%) than in urban areas (1.5%). Of the 721 children with a positive examination result, 424 pupils (58.8%) were reported as having been infested with head lice in the previous 6 months. Mother's education level was a significant risk factor in this model (p < 0.05). At 2 weeks after the primary treatment, the success rates of treatment were 49%. Comprehensive survey in our work showed the better future of the disease and related factors. Education campaigns by health care officials, physicians and teachers are expected to be helpful for head lice control. It is essential that governments should be supported form cooperation between the school authorities and public health centers to successful control head lice infestation in primary school. Also there is an urgent need to identify safe, novel insecticides for proved efficacy.     

The Highlighted Roles of Metabolic and Cellular Response to Stress Pathways Engaged in Circulating hsa-miR-494-3p and hsa-miR-661 in Alzheimer’s Disease

Background:Among different roles of miRNAs in AD pathogenesis, hsa-miR-494-3p and hsa-miR-661 functions are poorly understood. Methods:To obtain the gene targets, gene networks, gene ontology, and enrichment analysis of the two miRNAs, some web servers were utilized. Furthermore, the expressions of these miRNAs were analyzed by qRT-PCR in 36 blood sera, including 18 Alzheimer’s patients and 18 healthy individuals. Results:The in silico analysis demonstrated the highlighted roles of metabolic and cellular response to stress pathways engaged in circulating hsa-miR-494-3p and hsa-miR-661 in AD. The qRT-PCR analysis showed that the downregulated expression level of hsa-miR-661 was statistically significant (p < 0.05). Also, the ROC curve of hsa-miR-661 displayed the significant AUC (p = 0.01). Conclusion:Based on our findings, the metabolic and cellular responses to stress pathways are closely connected to these two miRNAs functions. Besides, the qRT-PCR and Roc curve determined hsa-miR-661 could be as a biomarker for diagnosis or prognosis of AD patients. Key Words: Alzheimer’s disease, Serum, Circulating microRNAs     

Toxicity of Nanoparticles and an Overview of Current Experimental Models

Nanotechnology is a rapidly growing field having potential applications in many areas. Nanoparticles (NPs) have been studied for cell toxicity, immunotoxicity, and genotoxicity. Tetrazolium-based assays such as MTT, MTS, and WST-1 are used to determine cell viability. Cell inflammatory response induced by NPs is checked by measuring inflammatory biomarkers, such as IL-8, IL-6, and tumor necrosis factor, using ELISA. Lactate dehydrogenase (LDH) assay is used for cell membrane integrity. Different types of cell cultures, including cancer cell lines have been employed as in vitro toxicity models. It has been generally agreed that NPs interfere with either assay materials or with detection systems. So far, toxicity data generated by employing such models are conflicting and inconsistent. Therefore, on the basis of available experimental models, it may be difficult to judge and list some of the more valuable NPs as more toxic to biological systems and vice versa. Considering the potential applications of NPs in many fields and the growing apprehensions of FDA about the toxic potential of nanoproducts, it is the need of the hour to look for new internationally agreed free of bias toxicological models by focusing more on in vivo studies. Key Words: Cytotoxicity, in vitro, Metal nanoparticles, Toxicology, Review     

Sperm quality in male <Emphasis Type="Italic">Barbus barbus</Emphasis> L. fed different diets during the spawning season

Sperm quality of Barbus barbus L. was compared among the three following dietary regimes: Group A, fed 100% commercial diet (Karpico™ containing 33% crude protein and 6% fat), Group B, fed 78% commercial diet and 22% frozen chironomid (Chironomus plumosus) larvae, and Group C, fed 56% commercial diet and 44% frozen chironomid larvae. Concentrations of polyunsaturated fatty acids (PUFAs) in Group A, B, and C were 39.1, 42.0, and 44.6, respectively, as a percentage of total fatty acids. Sperm morphology, volume, concentration and motility, total number of spermatozoa, and osmolality of the seminal plasma were compared during the spawning season. Dietary regime did not influence sperm volume, concentration, or total number of spermatozoa, osmolality of seminal plasma, or the percentage of motile sperm, but significantly affected sperm morphology (except for anterior and posterior parts of the midpiece) and sperm velocity (P < 0.05). Groups B and C showed similar sperm characteristics during the spawning season compared to Group A. Almost all parameters changed either among or within groups during the spawning season, suggesting differences in terms of the optimal time for sperm collection. The best time for sperm collection was March for Group A, but April for Groups B and C, when the osmolality of the seminal plasma measured 289 mOsmol kg⁻¹ and sperm motility was maximal. Spermatogenesis, hydration, and cell decomposition were confirmed as the three major parameters controlling sperm characteristics during the spawning season. The possible correlation between sperm morphology and motility requires further study.     

High-luminosity blue and blue-green gallium nitride light-emitting diodes

Compact and efficient sources of blue light for full color display applications and lighting eluded and tantalized researchers for many years. Semiconductor light sources are attractive owing to their reliability and amenability to mass manufacture. However, large band gaps are required to achieve blue color. A class of compound semiconductors formed by metal nitrides, GaN and its allied compounds AIGaN and InGaN, exhibits properties well suited for not only blue and blue-green emitters, but also for ultraviolet emitters and detectors. What thwarted engineers and scientists from fabricating useful devices from these materials in the past was the poor quality of material and lack of p-type doping. Both of these obstacles have recently been overcome to the point where highluminosity blue and blue-green light-emitting diodes are now available in the marketplace.     

Optimization of an artificial neural network topology using coupled response surface methodology and genetic algorithm for fluidized bed drying

In this study, an integrated response surface methodology (RSM) and genetic algorithm (GA) are recommended for developing artificial neural networks (ANNs) with great chances to be an optimal one. A multi-layer feed forward (MLFF) ANN was applied to correlate the outputs (energy and exergy) to the four exogenous inputs (drying time, drying air temperature, carrot cubes size, and bed depth). The RSM was used to build the relationship between the input parameters and output responses, and used as the fitness function to measure the fitness value of the GA approach. In the relationship building, five variables were used (number of neurons, momentum coefficient and step size in the hidden layer, number of epochs and number of training times). A polynomial model was developed from training results to mean square error (MSE) of 50 developed ANNs to generate 3D response surfaces and contour plots. Finally, GA was applied to find the optimal topology of ANN. The ANN topology had minimum MSE when the number of neurons in the hidden layer, momentum coefficient, step size, number of training epochs and training times were 28, 0.66, 0.35, 2877 and 3, respectively. The energy and exergy of carrot cubes during fluidized bed drying were predicted with R² values of greater than 0.97 using optimal ANN topology.     

三个农林复合树种幼苗对施加磷肥的响应:生长和生节能力(英文)

对苗床培养的楹树、雨豆树和水黄皮袋装幼苗(6月龄)施以80kg·hm-2的磷酸盐,通过比较不同收获间隔期幼苗生长和生节情况,研究了施加磷肥对三个农林复合树种幼苗生长和生节作用。研究表明,施加磷肥显著促进雨豆树和水黄皮幼苗生长,但并未促进楹树幼苗生长。此外,施加磷肥还会显著增加楹树、雨豆树幼苗生节数和节大小,但对水黄皮幼苗作用较小,而且高收割间隔期会降低水黄皮生节表现。     

Spatial and temporal variation in otolith chemistry and its relationship with water chemistry: Stock discrimination of Sperata aor

Long‐whiskered catfish, Sperata aor (Hamilton 1822), is commercially important in food, ornamental and sport fisheries. The fish is mainly caught from the wild populations because its aquaculture practices are not commercialised. Inland fishery in the Ganga basin is mostly unorganised; hence, no published report is available on the trend of S. aor production from the selected habitat. In India, S. aor has been categorised vulnerable mainly due to natural and anthropogenic threats. Otolith chemistry shows variation with changing physico‐chemical conditions of the fish habitat. Therefore, the present study was conducted with the objective to analyse spatio‐temporal variations in water chemistry in relation to environmental factors; relationship between water and otolith chemistry; and spatio‐temporal variations in otolith chemistry to discriminate the stocks of S. aor inhabiting the River Ganga. Most of the element: Ca ratios in water samples did not show significant correlations with environmental factors, viz. temperature and conductivity. Only few element: Ca concentrations in otoliths were positively correlated to their corresponding ratios in the ambient water. In the selected study area, the S. aor populations were discriminated into four stocks possibly because of heterogeneous water chemistry at the sampling sites, and physical barriers. In the present study, otolith chemistry showed relatively low temporal variability as compared to spatial variability; thus, the classification accuracy of individuals to their original populations remained consistent over the selected time period. The findings could be useful in devising scientifically sound management strategies and/or any conservation plans for the vulnerable S. aor populations inhabiting the River Ganga.     

Protective effect of dietary curcumin in Anabas testudineus (Bloch) with a special note on DNA fragmentation assay on hepatocytes and micronucleus assay on erythrocytes in vivo

The present study was conducted to evaluate the safety of long-term dietary curcumin at doses 0.5 and 1 % in Anabas testudineus employing hematological and cytological techniques. The fish were fed with curcumin-supplemented feed for 6 months. Fine blood smears were prepared and subjected to three different staining techniques. The erythrocyte micronucleus frequency (MN) and the cytometric measurements of erythrocytes were determined. Blood from the control and treated fish was subjected to the assessment of several hematological parameters. Also, DNA fragmentation assay on hepatocytes was conducted. The results showed that hemoglobin content, RBC count and hematocrit increased in the curcumin-fed fish compared to control, whereas WBC count, platelet count, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were unaffected. WBC/RBC ratio was lower in the case of curcumin-treated fish. The cytometric measurements revealed no change in the erythrocytes and their nuclei after curcumin treatment. DNA fragmentation assay revealed intact DNA in curcumin-fed group, ruling out the possibility of curcumin-induced DNA damage. The positive control group showed a significant increase in MN frequency compared to negative control and curcumin-fed groups. In fact, the MN frequency decreased in 1 % curcumin-fed group compared to the negative control and 0.5 % curcumin groups. All these indicated a state of well-being of the curcumin-treated fish. Therefore, it is concluded that curcumin could be used as a safe feed ingredient to improve the growth of finfish in aquaculture.