Electric field simulation of multi-needle water bath electrospinning and the structural properties of SCN/PAN micro/nanofiber composite yarns.

Multi-needle water bath electrospinning is one of the most efficient methods used to prepare micro/nanofiber composite yarns. The nanofiber structure can be targeted and regulated to obtain high-performance composite yarns. To explore the effect of the receiving distance on the structure and properties of micro/nanofiber composite yarns, polyacrylonitrile nanofibers were uniformly coated on silver-coated nylon yarn via a four-needle continuous water bath electrospinning method. The electric field distribution at different receiving distances was simulated by ANSYS finite element analysis software, and the effects of electric field distribution on the structure and properties of the micro/nanofiber composite yarns were studied. The results indicated that the peak electric field intensity appeared at the tip of the needles and decreased with the increase in the receiving distance. The receiving distance was constant, and the field intensity was lower when the direction of the centerline of the needle tip was farther away from the tip; however, the field intensity at the conductive core yarn was higher than that in the surrounding area (small spikes). The average field intensity of the small spikes at 180 mm was only 1/4 of that at 80 mm. When the receiving distance increased within a certain range (100∼140 mm), the nanofibers had a smooth surface and good separation, their diameters decreased continuously and the porosity changed inversely. With a further increase in the receiving distance, the nanofibers gradually bonded, their diameter increased and the porosity showed the opposite trend. The coating rate of the nanofibers showed a decreasing trend, and the mechanical properties of the micro/nano composite yarns were improved. When the receiving distance was 100 mm, the porosity reached 38.94%, and the breaking force, breaking elongation and breaking strength were 13.71 ± 1.36 cN, 22.76 ± 6.62% and 0.15 ± 0.02 cN·dtex-1, respectively. Upon consideration of all the above factors, the receiving distance of 100 mm is appropriate.

Study of Bioaccumulation, Hematological Parameters, and Antioxidant Responses of Carassius auratus gibelio Exposed to Dietary Lead and Bacillus subtilis.

Lead (Pb) is one of the most ubiquitous and toxic elements in the aquatic environment. Bacillus subtilis (B. subtilis) is a widely used probiotic in aquaculture. The aim of this study was to explore the toxic effects on bioaccumulation, hematological parameters, and antioxidant responses of Carassius auratus gibelio (C. gibelio) exposed to dietary lead at 0, 120, and 240 mg/kg and/or B. subtilis at 109 cfu/g. At 15 and 30 days, the fish were sampled and bioaccumulation, hematological parameters, and antioxidant responses were assessed. The result showed that B. subtilis administration can provide a significant protection against lead toxicity by reducing lead bioaccumulation in tissues, increasing the antioxidant enzymes activity, recovering δ-aminolevulinic acid dehydratase activity and optimizing the hematological parameters. Our results suggested that administration of B. subtilis (109 cfu/g) has the potential to combat dietary lead toxicity in C. gibelio.

Effect of sub-chronic exposure to lead (Pb) and Bacillus subtilis on Carassius auratus gibelio: Bioaccumulation, antioxidant responses and immune responses.

Lead (Pb) poisoning in humans and fish represents a significant global problem. Bacillus subtilis (B. subtilis) is a widely used probiotic in aquaculture. Carassius auratus gibelio (C. gibelio) is one of the most important aquaculture species with great commercial value. The objective of this study was to evaluate the potential of B. subtilis in ameliorating lead-induced toxicity in C. gibelio. The fish were exposed for 60 days to waterborne Pb at 0, 0.05, 0.5 and 1 mg/L and/or dietary B. subtilis at 109 cfu/g. After 30 and 60 days, the fish were sampled and bioaccumulation, antioxidant activity and immune responses were assessed. The results revealed that B. subtilis confers significant protective effects against lead toxicity by preventing alterations in the levels of bioaccumulation, superoxide dismutase, catalase and glutathione. B. subtilis also assists in the recovery of blood δ-aminolevulinic acid dehydratase, lysozyme, and IgM levels while regulating the expression of immune-related genes including IL-10, lysozyme, TNF-α, IgM and Hsp70 after 60 days of lead exposure. Our results suggest that administration of B. subtilis (109 cfu/g) has the potential to combat lead toxicity in C. gibelio.

Objective Ventricle Segmentation in Brain CT with Ischemic Stroke Based on Anatomical Knowledge.

Ventricle segmentation is a challenging technique for the development of detection system of ischemic stroke in computed tomography (CT), as ischemic stroke regions are adjacent to the brain ventricle with similar intensity. To address this problem, we developed an objective segmentation system of brain ventricle in CT. The intensity distribution of the ventricle was estimated based on clustering technique, connectivity, and domain knowledge, and the initial ventricle segmentation results were then obtained. To exclude the stroke regions from initial segmentation, a combined segmentation strategy was proposed, which is composed of three different schemes: (1) the largest three-dimensional (3D) connected component was considered as the ventricular region; (2) the big stroke areas were removed by the image difference methods based on searching optimal threshold values; (3) the small stroke regions were excluded by the adaptive template algorithm. The proposed method was evaluated on 50 cases of patients with ischemic stroke. The mean Dice, sensitivity, specificity, and root mean squared error were 0.9447, 0.969, 0.998, and 0.219 mm, respectively. This system can offer a desirable performance. Therefore, the proposed system is expected to bring insights into clinic research and the development of detection system of ischemic stroke in CT.