Strain-induced topological phase transition in phosphorene and phosphorene nanoribbons

Using the tight-binding (TB) approximation with inclusion of the spin-orbit interaction, we predict a topological phase transition in the electronic band structure of phosphorene in the presence of axial strains. We derive a low-energy TB Hamiltonian that includes the spin-orbit interaction for bulk phosphorene. Applying a compressive biaxial in-plane strain and perpendicular tensile strain in ranges where the structure is still stable leads to a topological phase transition. We also examine the influence of strain on zigzag phosphorene nanoribbons (zPNRs) and the formation of the corresponding protected edge states when the system is in the topological phase. For zPNRs up to a width of 100 nm the energy gap is at least three orders of magnitude larger than the thermal energy at room temperature.Comment: 10 pages, 6 figure

Visualizing particle networks in granular media by in situ X-ray computed tomography

In this contribution, cylindrical samples consisting of monodisperse soft (rubber) and stiff (glass) particles are pre-stressed under uniaxial compression. Acoustic P-waves at ultrasound frequencies are superimposed into prepared samples with different soft-stiff volume fractions. Earlier investigations showed the importance of particles networks, i.e. force chains, in controlling the effective mechanical properties of particulate systems. Measured P-wave modulus showed a significant decline while more soft particles are added due to a change in microstructure. However, for small contents of soft particles, it could be observed that the P-wave modulus is increasing. For the understanding of such kinds of effects, detailed insight into the microstructure of the system is required. To gain this information and link it to the effective properties, we made use of high-resolution micro X-ray Computed Tomography (micro-XRCT) imaging and combined it with the classical stiffness characterization. Both performed in situ meaning inside the laboratory-based XRCT scanner. With micro-XRCT imaging, the granular microstructure can be visualized in 3d and characterized subsequently. By post-processing of the data, the individual grains of the particulate systems could be uniquely identified. Finally, the contact network of the packings which connects the center of particles was established to demonstrate the network transition from stiff- to soft-dominated regimes. This has allowed for unprecedented observations and a renewed understanding of particulate systems. It has been demonstrated that micro-XRCT scans of particles packings can be analyzed and compared in 3d to gain extensive information on the scale of the single particles. Here, the in situ setup and workflow from the start of acquiring images in situ till the post-processing of the image data is explained and demonstrated by selected results.Comment: 17 pages, 10 figures, submitted to Survey for Applied Mathematics and Mechanics (GAMM Mitteilungen

Influence of 1 Alpha, 25-Dihydroxyvitamin D3 on T helper 17 cells and related cytokines in systemic lupus erythematosus

Background: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Emerging data suggests that T helper 17 (Th17) cells play a pathogenic role in SLE and the increased number of these cells correlates with disease activity. In recent years, 1α, 25-dihydroxyvitamin D3 (1,25VitD3) has been considered as an immunomodulatory factor. Objective: To investigate the effect of 1,25VitD3 on Th17 cells and on the expression of related cytokines in SLE patients. Method: Thirty SLE patients (newly diagnosed or in remission) were sampled for 10 ml whole blood to isolate peripheral blood mononuclear cells (PBMCs) using Ficoll-Hypaque density gradient centrifugation. Isolated cells were cultured in the presence and absence of 50 nM 1,25VitD3. After incubation, cells were harvested and stimulated for 4-5 hours with phorbol myristate acetate (PMA) and ionomycin in the presence of brefeldin A. IL-17 secreting cells were analyzed by flowcytometry. RNA was extracted from cultured cells, cDNA was synthesized, and the expression levels of IL-6, IL-17, IL-23 and TGF-β genes were assessed by real-time PCR. Results: The percentage of Th17 cells (CD3+CD8- IL-17+ T cells) decreased significantly in 1,25VitD3-treated cells (3.67 ± 2.43%) compared to untreated cells (4.65 ± 2.75%) (p=0.003). The expression of TGF-β up regulated (1.38-fold) and the expression of IL-6 (50%), IL-17 (27%) and IL-23 (64%) down regulated after 1,25VitD3 treatment. Conclusion: This study showed that 1,25VitD3 modulates Th17 related pathways in SLE patients and revealed the immunomodulatory effect of 1,25VitD3 on the Th17 mediated autoimmunity. © 2015, Shiraz University of Medical Sciences. All rights reserved

Effects of different heat processing methods of rapeseed on ruminal and post-ruminal nutrient disappearance

Due to improving the nutritive value of oilseeds and changing their digestion site in ruminants, processing, including heat treatment, seems necessary. The present research was conducted to evaluate the effect of applying heat processing such as roasting, microwaving and autoclaving on nutritive values; the amount and rate of degradability in rumen, and the disappearance of rapeseed nutrients in rumen, post-rumen and total tract. This evaluation was performed using mobile nylon bags techniques; three-step method of digestion and protein CNCPS fraction. A completely randomized design was used to investigate the effect of applying heat processing, and SAS software was used to analyze the data. The field Emission Scanning Electron Microscope was used to monitored the effect of heat treatment on surface of rapeseed. The application of heat processing in this research (roasting, microwaving and autoclaving) had no significant effect on the chemical composition of rapeseed. The results obtained from mobile nylon bags method and three-step digestion method showed that raw rapeseed has the highest disappearance of DM and CP in rumen and therefore has a significant difference with processed seeds (P<0.05). Also, the disappearance of DM and CP of processed rapeseed in intestines was significantly higher than raw seed (P<0.05), and this was higher than other processing for autoclaved rapeseed. According to the results obtained from CNCPS protein fractionation, applying heat processing altering protein fractionation (P<0.05). Applying microwave processing has created cracks in the surface of the rapeseed wall, and this condition was not observed in the wall surface of other heated seeds. In general, it can be said that in addition to increasing the digestibility of rapeseed in the entire gastrointestinal tract, applying heat processing reduces its degradability in the rumen and has increased the disappearance of nutrients in the intestine, that it can be stated the digestion site is altered from rumen to intestine, which can prevent the loss of protein sources in ruminant feed

TRANSFER LEARNING METHOD FOR SLEEP STAGES CLASSIFICATION USING DIFFERENT DOMAIN

Sleep stages classification using the signal analysis includes electroencephalogram (EEG), Electrooculography (EOG), Electromyography (EMG), Photoplethysmogram (PPG), and electrocardiogram (ECG). In this study, the proposed method using transfer learning to sleep stages classification. First, we have used the PPG and ECG signals, because they are less complex. This signal has the least complexity, and in this article we used this signal for transitional learning. n this study, we extracted 52 features from two signals and prepared for the classification stage. This method includes two steps, (a) Train data PPG and Test data ECG, (b) Train data ECG and Test data PPG. Results proved that our method has acceptable reliability for classification. The accuracy of 95.25% and 94.63% has been reached

The effect of alcoholic extracts of Arctium lappa L. and Satureja hortensis L. against Trichomonas vaginalis in vitro

Background: Trichomonas vaginalis infection is one of the most prevalent type of vaginitis in women. Considering the side effects of metronidazole and therapeutic properties of Arctium lappa L. and Satureja hortensis L. in traditional medicine, this study aimed to examine the anti-Trichomonas effects of Arctium lappa and Satureja hortensis alcoholic extracts in vitro. Materials and Methods: This experimental study was conducted on T. vaginalis isolated from 1203 persons referred to five health centers in Kashan city. Five T. vaginalis isolates were cultured in a TYI-S-33 medium and were used to study the effect of Arctium lappa and Satureja hortensis extracts. The effects of different concentrations (12.5, 25, 50, 100, 200, 400, 800 and 1000 µg/mL) of plant extracts on the growth of T. vaginalis trophozoeites were studied 12, 24, and 48 h after the culture. Also, the culture media and metronidazole (0.025, 0.05, 0.1, 0.2, 0.4 µg/mL) were considered as the negative and positive controls, respectively. The effects of the extracts and drug were examined by counting the number of live and dead parasites using the trypan blue staining method. Results: Results showed that the alcoholic extracts of Satureja hortensis and Arctium lappa had an inhibitory effect on the growth of T. vaginalis. The IC50 values of the alcoholic extracts of Satureja hortensis, Arctium lappa and metronidazole after 24 h were 190.8, 996.7 and 0.0326 µg/mL, respectively. Conclusion: The present study shows the in vitro anti-Trichomonas effect of Arctium lappa and Satureja hortensis extracts. The anti-Trichomonas effect of Satureja hortensis extract was higher than that of the Arctium lappa extract. Further studies are recommended to investigate the anti-Trichomonas effect of major components of these plants, especially the Satureja hortensis extract

The effect of dietary nucleotide on the haematological and serum biochemical parameters of Persian sturgeon (Acipenser persicus) juveniles

This study was aimed to examine the impact of different levels of dietary nucleotides (Vannagen) on serum biochemical and blood parameters of Persian sturgeon (Acipenser persicus). Fish (42.37± 2.12 g and 23.67± 0.61 cm) were divided into four treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 percent of diet). There were three replicates with a density of 12 fish per tank. After 10 weeks of feeding, serum biochemical and blood parameters were measured. Among the measured factors, blood glucose, triglycerides, cholesterol, erythrocyte and heterophil showed significant differences between the groups fed with nucleotides and the control group (P ≤ 0.05). By increasing the nucleotide levels, the mean heterophil and serum glucose showed significant increase and decrease, respectively. The highest and lowest values of cholesterol and triglyceride were found in groups fed with 0.25% and 0.35% nucleotides, respectively. The other measured factors had no significant difference (P≤0.05). Therefore, it could be said that with regard to the limited capacity of cells to synthesize nucleotides, external preparing of nucleotides could result in the production of needed nucleotides and an increase of its production speed, especially during stress. Such preparation can also improve fish physiology and health status