Net Section Fracture Assessment of Welded Rectangular Hollow Structural Sections

Rectangular Hollow Sections (RHS) because of their high resistance to tension, as well as compression, are commonly used as a bracing member with slotted gusset plate connections in steel structures. Since in this type of connection only part of the section contributes in transferring the tensile load to the gusset plate, shear lag failure may occur in the connection. The AISC specification decreases the effective section net area by a factor to consider the effect of shear lag for a limited connection configuration. This study investigates the effective parameters on the shear lag phenomenon for rectangular hollow section members connected at corners using a single concentric gusset plate. The results of the numerical analysis show that the connection length and connection eccentricity are the only effective parameters in the shear lag, and the effect of gusset plate thickness is negligible because of the symmetric connection. The ultimate tensile capacity of the suggested connection in this study were compared to the typical RHS connection presented in the AISC and the similar double angle sections connected at both legs. The comparison indicates that tensile performance of the suggested connection in this study because of its lower connection eccentricity is much higher than the typical slotted connection and double angle connections. Therefore, a new equation is suggested based on the finite element analyses to modify the AISC equation for these connections

Differentiation of Biliary Atresia from the Intrahepatic Etiology of Infantile Cholestasis with Alagille Criteria

Background: Biliary atresia (BA) is an important etiology of liver disease in pediatric patients which manifests as extrahepatic cholestasis. Alagille criterion is a combination of noninvasive findings for the diagnosis of BA. In this regard, the current retrospective study aimed to evaluate the diagnostic accuracy of Alagille criteria for BA. Methods: This cross-sectional study was conducted in Ghaem Hospital, affiliated to Mashhad University of Medical Sciences during 2009-2014. All infants less than 2 years old with cholestasis referred to the pediatric gastrointestinal ward were included in this study. Alagille criteria were evaluated for each patient, and BA was confirmed with intraoperative cholangiography. Finally, sensitivity, specificity, and positive and negative predictive values of Alagille criteria were determined according to the final diagnosis. Results: In general, 92 patients were included in this study. The male-to-female ratio and the mean age of patients were 54/38 and 42±5 days (ranging between 1 and 5 months), respectively. There was a significant difference between the two groups in terms of gender, onset time of jaundice, and the presence of the acholic stool (P=0.02, 0.04, and 0.005, respectively). Eventually, the acholic stool had the highest sensitivity, specificity, and positive and negative predictive values. Conclusion: Based on the findings, the presence of the acholic stool was the most valuable criterion for the diagnosis of BA among all Alagille criteria

Detection of Vibrio Species Isolated from Ornamental Guppy Fish in Kashan, Isfahan, Iran Fish culturing Pounds

Introduction: Gram-negative bacteria are the most pathogenic bacteria for marine organisms including ornamental fish. Materials and methods: In the present study Vibrio species isolated from ornamental guppy fish in Kashan, Isfahan, Iran fish ponds and were detected according to molecular detection and genetic alignment. Liver, kidney, skin, brain and gill samples were taken from ornamental guppy fish in Kashan, Isfahan, Iran. Samples were cultured on enriched culture media and purification steps were performed based on microbiological methods. Primary identification was done using biochemical characterization of the isolated bacteria. Molecular detection was done based on amplification of 16SrDNA sequence of Vibrio cholera genome containing ITS (internal transcribed spacer); and sequence alignment of the amplified nucleotides. Results: The isolated bacteria detected as Vibrio spp., including Vibrio cholera (99% sequence similarity), Vibrio alginolyticus, Vibrio mimicus and Vibrio parahaemolyticus (up to 90% similarity in the genome sequence). The aquaculture ponds had alkaline water and the amount of five-day BOD was not in a safe range, which are favorable conditions for Vibrio species. Discussion and conclusion: Aquatic organisms in Iran can be carriers of human pathogens such as Vibrio species. The results obtained in the present study and similar investigations should be mentioned in aquaculture healthcare systems

Enhancing the security of patients’ portals and websites by detecting malicious web crawlers using machine learning techniques

Introduction: There is increasing demand for access to medical information via patients’ portals. However, one of the challenges towards widespread utilisation of such service is maintaining the security of those portals. Recent reports show an alarming increase in cyber-attacks using crawlers. These software programs crawl web pages and are capable of executing various commands such as attacking web servers, cracking passwords, harvesting users’ personal information, and testing the vulnerability of servers. The aim of this research is to develop a new effective model for detecting malicious crawlers based on their navigational behavior using machine-learning techniques. Method: In this research, different methods of crawler detection were investigated. Log files of a sample of compromised web sites were analysed and the best features for the detection of crawlers were extracted. Then after testing and comparing several machine learning algorithms including Support Vector Machine (SVM), Bayesian Network and Decision Tree, the best model was developed using the most appropriate features and its accuracy was evaluated. Results: Our analysis showed the SVM-based models can yield higher accuracy (f-measure = 0.97) comparing to Bayesian Network (f-measure = 0.88) and Decision Tree (f-measure = 0.95) and artificial neural network (ANN) (f-measure = 0.87)for detecting malicious crawlers. However, extracting proper features can increase the performance of the SVM (f-measure = 0.98), the Bayesian network (f-measure = 0.94) and the Decision Tree (f-measure = 0.96) and ANN (f-measure = 0.92). Conclusion: Security concerns are among the potential barriers to widespread utilisation of patient portals. Machine learning algorithms can be accurately used to detect malicious crawlers and enhance the security of sensitive patients’ information. Selecting appropriate features for the development of these algorithms can remarkably increase their accuracy

Evaluation of the Sodium Serum Level in Infants with Jaundice

Background: Inadequate milk intake during the first year of neonate’s life can result in weight loss, severe hyperbilirubinemia, and sometimes hypernatremia. In this study, we aimed to determine the relationship between neonatal weight loss and hypernatremia in term breastfed infants with idiopathic jaundice, as well as the necessity of sodium concentration measurement in newborns with idiopathic jaundice via weight loss measurement. Methods: In this cross-sectional study, we examined 273 infants with jaundice of unknown etiology at Ghaem Hospital, Mashhad, in years 2008-2012. The study sample consisted of 226 infants in the control group (serum sodium concentratio

Hypoxia-related long noncoding RNAs are associated with varicocele-related male infertility.

One of the main molecular causes that contributes to varicocele-related male infertility is excess production of reactive oxygen species (ROS). It is believed that hypoxia is an important stimulator of ROS in this condition. Recently, the significant roles of long non-coding RNAs (lncRNAs) in hypoxia response have emerged. Despite the investigation of hypoxia, there is scant information about the role of hypoxia-responding lncRNAs in varicocele-related male infertility. In the present study, we deduced eight hypoxia-responding lncRNAs based on high-throughput RNA sequencing data from two Gene Expression Omnibus (GEO) datasets. We used qRT-PCR to assess the expression levels of some of these lncRNAs in 42 ejaculated spermatozoa samples from 25 infertile men with varicocele and 17 fertile men as controls. We identified significant increases in expression levels of hypoxia-related lncRNAs, MIR210HG and MLLT4-AS1 in ejaculated spermatozoa of infertile men with varicocele. These lncRNAs also showed significant positive correlations with ROS levels and meaningful negative correlations with sperm parameters (count and motility). Besides, in silico studies identified several hypoxia response elements (HREs) within selected lncRNAs promoters. Delineation of hypoxia-related lncRNAs in varicocele-related infertility provides a valuable insight into male infertility