Dynamic extended finite element method (XFEM) analysis of discontinuous media

The extended finite element method (XFEM) is found promising in approximating solutions to locally non-smooth features such as jumps, kinks, high gradients, inclusions, or cracks in solid mechanics problems. The XFEM uses the properties of the partition of unity finite element method (PUFEM) to represent the discontinuities without the corresponding finite element mesh requirements. In the present thesis numerical simulations of statically and dynamically loaded heterogeneous beams, heterogeneous plates and two-dimensional cracked media of isotropic and orthotropic constitutive behaviour are performed using XFEM. The examples are chosen such that they represent strong and weak discontinuities, static and dynamic loading conditions, anisotropy and isotropy and strain-rate dependent and independent behaviours. At first, the Timoshenko beam element is studied by adopting the Hellinger-Reissner (HR) functional with the out-of-plane displacement and through-thickness shear strain as degrees of freedom. Heterogeneous beams are considered and the mixed formulation has been combined with XFEM thus mixed enrichment functions are used. The results from the proposed mixed formulation of XFEM correlate well with analytical solutions and Finite Element Method (FEM) and show higher rates of convergence. Thus the proposed method is shear-locking free and computationally more efficient compared to its conventional counterparts. The study is then extended to a heterogeneous Mindlin-Reissner plate with out-of-plane shear assumed constant through length of the element and with a quadratic distribution through the thickness. In all cases the zero shear on traction-free surfaces at the top and bottom are satisfied. These cases involve weak discontinuity. Then a two-dimensional orthotropic medium with an edge crack is considered and the static and dynamic J-integrals and stress intensity factors (SIF’s) are calculated. This is achieved by fully (reproducing elements) or partially (blending elements) enriching the elements in the vicinity of the crack tip or body. The enrichment type is restricted to extrinsic mesh-based topological local enrichment in the current work. A constitutive model for strain-rate dependent moduli and Poisson ratios (viscoelasticity) is formulated. The same problem is studied using the viscoelastic constitutive material model implemented in ABAQUS through an implicit user defined material subroutine (UMAT). The results from XFEM correlate well with those of the finite element method (FEM). It is shown that there is an increase in the value of maximum J-integral when the material exhibits strain rate sensitivity.Open Acces

Evaluation of the changes in the expression levels of miR-141 and SHP gene in prostate cancer specimens

Introduction: Primary screening tests currently used for prostate cancer (PCa), don’t have sufficient sensitivity and specificity. Therefore, early diagnosis and management of treatment is one of the challenges faced by physicians. Today, more familiar with the signaling pathways involved in the pathogenesis of cancers, several molecules have been introduced as diagnostic biomarker or drug design. The androgen receptor is one of the most important pathways involved in the pathogenesis of PCa. The miR-141, as a member of the miR-200 family has a regulatory role by targeting the Small heterodimer partner (SHP , NR0B2) at the downstream of this molecular pathway. Objective: The aim of this study was to investigate changes in the expression of miR-141 and SHP in tissue samples of PCa patients compared to benign prosttic hyperplasia (BPH) tissues. Method: In this study, changes in expression of miR-141 and SHP at the RNA level were performed using qRT-PCR technique on 68 prostate tissues containing, 26 localized PCa, 4 metastatic PCa, 30 BPH and 8 tumor-adjacent normal tissues. Also, the analysis of the results was investigated using REST software. Changes in SHP expression at protein level were investigated in 20 Paraffin-embedded tissue blocks containing 10 PCa and 10 BPH using immunohistochemistry (IHC). Results: The findings of this study showed that miR-141 increased in metastatic samples compared with localized samples (P <0.001, 31.17-fold change). Tumor samples showed a lower expression level of SHP compared with BPH tissues at mRNA and protein level (p = 0.014, 4.7 fold change) and (p = 0.02, 1.8 fold change), respectively. Conclusion: According to our results, it can be concluded that miR-141 plays a role in the pathogenesis of PCa through the androgen receptor signaling pathway and the SHP regulation. Also, miR-141 has a high potential for diagnosis of PCa as a prognostic biomarker. Keywords: Prostate cancer, SHP gene, miR-141, Biomarke

Macroscopic and microscopical investigations of the effects of alcoholic extract of henna (Lawsonia inermis) on skin healing of experimentally induced tissue damage in macro fish (Labidochromis caeruleus)

One of the well-known herbal drugs is henna (Lawsonia inermis). According to the components in henna, several beneficial properties (i.e., antimicrobial, anti-inflammation, wound healing, trypsin inhibitory and antioxidant) have been reported. The present study was designed to investigate the effects of two natural substances (sodium chloride and henna extract) on experimental skin lesion due to pulling out scales and trypsin injection (0/02 ml, beneath dorsal fin). For this purpose, 54 fish in weight 5/5±0/55 of were divided to 3 groups, with eighteen fish in each group. Fishes were placed in laboratory condition in 22-25 ˚C. Two, four and six days after induction of skin injury, fishes were treated with different agents for 10 minutes. First group was treated in salt water 1%, second group in henna extract 0.5% and the control group without any additives. The fish were sampled weekly, 3 times by sampling from the wound. Macroscopic examination showed that color changes of wound place decreased in henna group in comparison with that other groups. In third week of healing, normal appearance of skin were seen in most of fishes in henna and salt groups. Microscopic study revealed a decrease in inflammatory cells infiltration in henna group second week after induction of skin injury. It seems that henna by decreasing inflammatory process, can also prevent skin damage and secondary infections that can help faster and more effective on wound healing than salt bath in fish

Evaluation of the Housekeeping Genes; β‐Actin, Glyceraldehyde‐3‐Phosphate‐Dehydrogenase, and 18S rRNA for Normalization in Real‐Time Polymerase Chain Reaction Analysis of Gene Expression in Human Adipose Tissue

Background: Several studies suggested that beta-actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and 18S rRNA are expressed constitutively and contribute to the fundamental reference actions essential for cell viability and maintenance. However, there are inconsistency in this regard. Hence, we aimed to evaluate the accuracy of these three potential reference genes for Real‐Time quantitative reverse transcriptase‐polymerase chain reaction (qRT‐PCR) application for normalization in two types of human adipose tissues.Materials and Methods: Subcutaneous and visceral fat tissues were derived from 19 healthy and 20 obese subjects and RT-qPCR was applied to determine the expression levels of beta-actin, GAPDH, and18S rRNA.Results: The gene expression level of beta-actin, GAPDH, and 18S rRNA was essentially the same in the subcutaneous and visceral fat tissues of all participants (P&gt;0.05). Hence, all considered housekeeping genes displayed high expression stability and the analysis revealed that normalization to all of these three housekeeping genes gave a result that satisfactorily reflected the acceptable mRNA expression levels in adipose tissues.Conclusion: Collectively, our findings suggest of beta-actin, GAPDH, and18S rRNA as reference genes applicable in human adipose tissue in the context of obesity

Adaptive Rat Swarm Optimization for Optimum Tuning of SVC and PSS in a Power System

This paper presents a new approach for the coordinated design of a power system stabilizer- (PSS-) and static VAR compensator- (SVC-) based stabilizer. For this purpose, the design problem is considered as an optimization problem, while the decision variables are the controllers' parameters. This paper proposes an effective optimization algorithm based on a rat swarm optimizer, namely, adaptive rat swarm optimization (ARSO), for solving complex optimization problems as well as coordinated design of controllers. In the proposed ARSO, instead of a random initial population, the algorithm starts the search process with fitter solutions using the concept of the opposite number. In addition, in each iteration of the optimization, the new algorithm replaces the worst solution with its opposite or a random part of the best solution to avoid getting trapped in local optima and increase the global search ability of the algorithm. The performance of the new ARSO is investigated using a set of benchmark test functions, and the results are compared with those of the standard RSO and some other methods from the literature. In addition, a case study from the literature is considered to evaluate the efficiency of the proposed ARSO for coordinated design of controllers in a power system. PSSs and additional SVC controllers are being considered to demonstrate the feasibility of the new technique. The numerical investigations show that the new approach may provide better optimal damping and outperform previous methods

Ileal intussusception secondary to both lipoma and angiolipoma: a case report

Lipoma and angiolipoma are common benign neoplasms that occur in the subcutaneous tissue and rarely in the gastrointestinal tract. These tumors are usually asymptomatic but may present with abdominal pain, bleeding and obstruction. We present a 53-years-old woman with abdominal discomfort for several weeks accompanied with bloody diarrhea and recurrent vomiting. Ileo-ileal invagination was diagnosed by computed tomography scan. Laparotomy revealed five intraluminal masses that caused intussusception. Histopathological study showed that one was angiolipoma and other lesions were lipoma. We have described some aspects of diagnosis and treatment of this rare cause of intestinal intussusception

Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology

Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)

Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology

Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)

Downregulation of miR-1266-5P, miR-185-5P and miR-30c-2 in prostatic cancer tissue and cell lines

Over the latest decade, the role of microRNAs (miRNAs/miRs) has received more attention. miRNAs are small non-coding RNAs that may serve a role as oncogenes or tumor suppressor genes. Certain miRNAs regulate the apoptosis pathway by influencing pro- or anti-apoptotic genes. We hypothesized that increases in the expression of B cell lymphoma 2 (BCL2) and BCL2-like 1 (BCL2L1) genes, which have been reported in various types of cancer tissues, may be due to the downregulation of certain miRNAs. The present study aimed to identify miRNAs that target BCL2 and BCL2L1 anti-apoptotic genes in prostate cancer (PCa) clinical tissue samples. Certain candidate miRNAs were selected bioinfor-matically and their expression in PCa samples was analyzed and compared with that in benign prostatic hyperplasia (BPH) tissue samples. The candidate miRNAs that targeted BCL2 and BCL2L1 genes were searched in online databases (miRWalk, microRNA.org, miRDB and TargetScan). A total of 12 miRNAs that target the 3'-untranslated region of the aforementioned genes and/or for which downregulation of their expression has previously been reported in cancer tissues. A total of 30 tumor tissue samples from patients with PCa and 30 samples tissues from patients with BPH were obtained and were subjected to reverse transcription-quantitative polymerase chain reaction for expression analysis of 12 candidate miRNAs, and the BCL2 and BCL2L1 genes. Additionally, expression of 3 finally selected miRNAs and genes was evaluated in prostate cancer PC3 and DU145 cell lines and human umbilical vein endothelial cells. Among 12 miRNA candidates, the expression of miR-1266, miR-185 and miR-30c-2 was markedly downregulated in PCa tumor tissues and cell lines. Furthermore, downregulation of these miRNAs was associated with upregulation of the BCL2 and BCL2L1 genes. An inverse association between three miRNAs (miR-1266, miR-185 and miR-30c-2) and two anti-apoptotic genes (BCL2 and BCL2L1) may be considered for interventional miRNA therapy of PCa. © 2018, Spandidos Publications. All rights reserved

Downregulation of miR-1266-5P, miR-185-5P and miR-30c-2 in prostatic cancer tissue and cell lines

Over the latest decade, the role of microRNAs (miRNAs/miRs) has received more attention. miRNAs are small non-coding RNAs that may serve a role as oncogenes or tumor suppressor genes. Certain miRNAs regulate the apoptosis pathway by influencing pro- or anti-apoptotic genes. We hypothesized that increases in the expression of B cell lymphoma 2 (BCL2) and BCL2-like 1 (BCL2L1) genes, which have been reported in various types of cancer tissues, may be due to the downregulation of certain miRNAs. The present study aimed to identify miRNAs that target BCL2 and BCL2L1 anti-apoptotic genes in prostate cancer (PCa) clinical tissue samples. Certain candidate miRNAs were selected bioinfor-matically and their expression in PCa samples was analyzed and compared with that in benign prostatic hyperplasia (BPH) tissue samples. The candidate miRNAs that targeted BCL2 and BCL2L1 genes were searched in online databases (miRWalk, microRNA.org, miRDB and TargetScan). A total of 12 miRNAs that target the 3'-untranslated region of the aforementioned genes and/or for which downregulation of their expression has previously been reported in cancer tissues. A total of 30 tumor tissue samples from patients with PCa and 30 samples tissues from patients with BPH were obtained and were subjected to reverse transcription-quantitative polymerase chain reaction for expression analysis of 12 candidate miRNAs, and the BCL2 and BCL2L1 genes. Additionally, expression of 3 finally selected miRNAs and genes was evaluated in prostate cancer PC3 and DU145 cell lines and human umbilical vein endothelial cells. Among 12 miRNA candidates, the expression of miR-1266, miR-185 and miR-30c-2 was markedly downregulated in PCa tumor tissues and cell lines. Furthermore, downregulation of these miRNAs was associated with upregulation of the BCL2 and BCL2L1 genes. An inverse association between three miRNAs (miR-1266, miR-185 and miR-30c-2) and two anti-apoptotic genes (BCL2 and BCL2L1) may be considered for interventional miRNA therapy of PCa. © 2018, Spandidos Publications. All rights reserved