21 research outputs found
Experimental Investigation on the Structural Behavior of Double Channel Castellated Steel Beams
The main idea of castellated steel beams is to reduce their weight by creating void space (web holes) in the main beam body. This structure tends to exhibit superior properties such as advanced strength, lightweight, and cost-saving compared to the amount of steel used compared with reference beam without web holes. This study is devoted to investigating the structural behavior of double-channel cast steel beams. In this project, two pieces of a rolled hot steel channel were connected to form a new section used in the testing program. Five beams of different sections were manufactured and tested using the same length and all testing parameters conditions with only a difference in the number of openings and distance (e) between each hole to study the behavior of section to different bearing loads and deformation. Two loading points were placed on a third of the length of the castellated steel beam. This study showed that when the web holes are few, the total bearing strength decreases. As the number of web holes increased to a specific limit, the bearing strength continued to rise, and if openings exceeded a specific limit, the bearing force decreased. The rate of increase to the bearing force was found between 17.7-40.0%. Lastly, as per beam deformation, the deformation value decreased as the number of openings increased, which was taken at the maximum load of the reference beam
Compressive Strength and Shrinkage Behavior of Concrete Produced from Portland Limestone Cement with Water Absorption Polymer Balls
Karyotyping and neurodevelopmental follow-up of intracytoplasmic sperm injection children up to 4years of age
Objectives: The aim of this work is to study ICSI babies, singleton and twins and compare them with singleton naturally conceived children from the genetic and neurodevelopmental point of view.
Materials and methods: This is a prospective study performed on 120 children born to 100 mothers after the successful treatment of male infertility by intracytoplasmic sperm injection (ICSI). Obstetric history and Neonatal examinations were done. Developmental assessment using Denver Developmental Screening Test was done at 1, 2, 3, and 4years of age. Karyotype was done to all babies. The babies were divided into three study groups; group 1 single ICSI, group 2 twin ICSI, and group 3 normally conceived control group.
Results: We found no statistically significant difference when we correlated outcome of DDST to gender, mode of delivery, smoking habits of mother, maternal illnesses, paternal smoking, Apgar score, congenital anomalies or type of feeding. There was significant statistical difference between the results of DDST follow-up and gestational age, birth weight and NICU admission. Our developmental assessment using DDST reported that ICSI children in both groups do not display any significant developmental delay when compared with naturally conceived children.
Conclusion: Developmental assessment performed in this study revealed reassuring findings, no important differences between ICSI and NC children were noticed indicating that infertility treatment by ICSI technique does not appear to affect the development of child. It also highlights the need for continuous follow-up to evaluate whether ICSI children continue to show satisfactory development later in life
Involvement of the α7-nicotinic acetylcholine receptors in the anti-inflammatory action of the thymulin-related peptide (PAT)
Background and Purpose: Peptide analog of thymulin (PAT) has been shown to have anti-hyperalgesic and anti-inflammatory properties in animal models of inflammation. Recent reports suggest that the peripheral cholinergic system has an anti-inflammatory role mediated by α7-nicotinic acetylcholine receptor (α7-nAChR). Our aim is to investigate whether the action of PAT is mediated, via the cholinergic pathway. Experimental Approach: The anti-hyperalgesic and anti-inflammatory action of PAT was assessed in rat models of inflammatory nociceptive hyperactivity (carrageenan and endotoxin) and in a mice air-pouch model for localized inflammation, respectively; the possible attenuation of PAT\u27s effects by pretreatment with the α7-nAchR specific antagonist methyllycaconitine citrate (MLA) was also investigated. In another series of experiments, using two electrode recordings, the effect of PAT on the α7-nAChRs, expressed in Xenopus Oocytes, was also determined. Key Results: Administration of PAT reversed inflammatory nociceptive hyperactivity and cold and tactile hyperactivity in rats. This effect was partially or totally prevented by MLA, as assessed by different behavioral pain tests. Treatment with PAT also reduced the alteration of cytokines and NGF levels by carrageenan injection in the mouse air pouch model; this effect was partially antagonized by MLA. Electrophysiological recording demonstrated that PAT significantly potentiated the α7-nAchR expressed in Xenopus Oocytes. These effects were not observed when a control peptide, with a reverse sequence (rPAT), was utilized. Conclusions and Implications: The behavioral and electrophysiological observations described in this report demonstrate that PAT mediates, at least partially, its anti-inflammatory action by potentiating the α7-nAChR. These results indicate that PAT has a potential for new therapeutic applications as anti-inflammatory and analgesic agent. © 2013 IBRO
Recommended from our members
High Frequency of Chromosome 9p Allelic Loss and CDKN2 Tumor Suppressor Gene Alterations in Squamous Cell Carcinoma of the Bladder
Background: In the Western Hemisphere, 90% of bladder cancers are transitional cell carcinomas, while only 7% are classified as squamous cell carcinomas. In contrast, in Egypt and regions of the Middle East and Africa, where infection by the trematode Schistosoma haematobium is endemic, squamous cell carcinoma is the most common bladder cancer as well as the most common cancer in men. Purpose: We planned experiments to understand the genetic defects underlying the development of squamous cell carcinoma and to determine if the morphologically and clinically distinct squamous cell carcinoma and transitional cell carcinoma of the bladder evolve following different genetic alterations. Methods: Squamous cell carcinoma specimens from high-risk (Egypt, n = 19) and low-risk (Sweden, n = 12) populations were examined for genetic defects known to be involved in transitional cell carcinoma tumorigenesis. Homozygous deletions of the CDKN2 tumor suppressor gene were detected by comparative multiplex polymerase chain reaction. Mutations in the CDKN2 and p53 (also known as TP53) genes were analyzed by single-strand conformation polymorphism and DNA sequencing. Immunohistochemical staining of p53 protein was also performed. Allelic losses in chromosome arms 9p, 9q, and 17p were determined by microsatellite analysis. Results: Homozygous deletions and sequence mutations in the CDKN2 gene were found in 67% (eight of 12) of squamous cell carcinoma specimens, a frequency three times higher than that reported for uncultured transitional cell carcinomas (P = .009). Hemizygous and homozygous deletions in 9p, where CDKN2 resides, were found in 92% (11 of 12) of uncultured squamous cell carcinomas, while only about 39% (35 of 90) of transitional cell carcinomas showed these losses (P = .001). Deletions in 9p with no change in 9q were found in 92% (10 of 11) of squamous cell carcinomas compared with only 10% (11 of 110) of transitional cell carcinomas (P<.001) reported in the literature. The frequency of p53 mutations in squamous cell carcinomas was similar to that reported for invasive transitional cell carcinomas (60%), but the type and position of mutations differed between the two tumor types. Allelic losses in chromosome arm 17p, where the p53 gene resides, were found to be less frequent in squamous cell carcinomas (38%) than in invasive transitional cell carcinomas (60%). Conclusions: Our results suggest that a putative tumor suppressor gene on 9p, possibly CDKN2, may contribute to squamous cell carcinoma tumorigenesis. Our data on squamous cell carcinoma and previously reported data on transitional cell carcinoma indicate that these two bladder carcinomas differ in their genetic alterations, suggesting that distinct underlying genetic defects may explain, at least in part, the pathological differences between the two tumors of the bladder epithelium. Implications: Development of diagnostic and therapeutic strategies for squamous cell carcinoma of the bladder based on its distinct genetic alterations is warranted. [J Natl Cancer Inst 1995;87:1383-93