Structural Behavior of FRP-Retrofitted RC Beams under Combined Torsion and Bending

Fiber-reinforced polymers (FRPs) retrofit reinforced concrete (RC) structures. ABAQUS finite element software was used to perform numerical parametric analysis on a group of RC beams in this research. All specimens were retrofitted by FRP strips as an external retrofitting and experimentally tested up to previous researchers’ failure points. The range of subjects examined in these RC beams included cracking torque, ultimate torque, angle of twist, and the effect of using FRP on these subjects. We applied artificial neural networks (ANNs) to predict the structural behavior of RC beams under combined torsion and bending to develop the research accuracy. After testing, the ANN results were compared with the ABAQUS results. Consequently, a reasonable examination of the determined mathematical and trial results confirmed this study’s logical accuracy in predicting retrofitted RC beams’ structural behavior under combined loading.     

Ultrasonographic analysis versus histopathologic evaluation of carotid advanced atherosclerotic stenosis in an experimental rabbit model

Advanced carotid atherosclerosis with severe stenosis (>70%) is a major clinical risk factor for ischemic stroke. Our ability to test new protocols for the treatment of atherosclerotic stenosis in humans is limited for obvious ethical reasons; therefore, a suitable animal model is required. The aim of this study was to generate an easily reproducible and inexpensive experimental rabbit carotid model of advanced atherosclerosis with morphological similarities to the human disease and the subsequent assessment of the reliability of B-mode ultrasound technology in the study of lumen area stenosis in this model. Briefly, New Zealand white rabbits underwent primary perivascular cold injury at the right common carotid artery followed by a 1.5% cholesterol-rich diet injury for eight weeks. All of the rabbits' arteries were imaged by B-mode ultrasound weekly, after which the rabbits were sacrificed, and their vessels were processed for histopathology. Ultrasound longitudinal view images from three cardiac cycles were processed by a new computerized analyzing method based on dynamic programming and maximum gradient algorithm for measurement of instantaneous changes in arterial wall thickness and lumen diameter in sequential ultrasound images. Histopathology results showed progressive changes, from the lipid-laden cells and fibrous connective tissue proliferation in neointimal layer, up to the fibro-lipid plaque formation, resulting in vessel wall thickening, remodeling and lumen stenosis. The B-mode ultrasound images and the histologic measurements showed an increase in the mean wall thickness and the lumen area stenosis within eight weeks. Quantitative and morphometric analysis of the mean wall thickness and the lumen area stenosis percentage showed a significant correlation between the B-mode ultrasound and the histological measurements at each time point (R = 0.989 and R = 0.995, p < 0.05, respectively). In conclusion, we successfully produced advanced atherosclerosis in the rabbit carotid artery that is similar to the condition seen in patients. This condition in rabbits can be properly assessed by B-mode ultrasound image processing.     

The discovery of a Persian family with a form of Birt–Hogg–Dubé syndrome lacking the typical cutaneous stigmata of the syndrome

PurposeThis study was performed in 24 members of a family with spontaneous pneumothorax to test clinical suspicion of Birt–Hogg–Dubé syndrome (BHDS).MethodsComputed tomography scan was performed for confirmation of pneumothorax, while genetic tests were done using real-time quantitative polymerase chain reaction.ResultsGenetic studies showed a deletion of exon 1 in the FLCN gene in the index case as well as nine other individuals, including two with clinical phenotypes of pneumothorax and seven who are symptom-free to date.ConclusionsProper imaging and taking accurate family history could be the keys to test clinical suspicion in some syndromes, including BHDS.     

Histopathological evaluation of pulpotomy with Er,Cr:YSGG laser vs formocresol

The purpose of this study was to histologically investigate whether pulpotomy with Er,Cr:YSGG laser is an acceptable alternative for formocresol. Pulpotomy of 48 dog’s primary canine teeth was performed with formocresol or Er,Cr:YSGG laser. Histological evaluations on hematoxylin and eosin-stained pulp tissues were made by an optical microscope 7 or 60 days later. Statistical analysis was performed with Fisher’s exact test, Mann–Whitney U test, and Student’s t test. Seven days after pulpotomy, samples treated with laser had significantly favorable histological features in the following measures: continuity of odontoblastic layer (P < 0.001), presence of hemorrhage (P < 0.008), amount of inflammation (P < 0.002), tissue necrosis (P < 0.001), internal resorbtion (P < 0.002), level of vascularization (P < 0.002), and size of abscess (P < 0.041). Similar results were observed 60 days after pulpotomy, except that the differences were not mostly significant due to natural exfoliation of 16 teeth. In conclusion, Er,Cr:YSGG laser system is an acceptable alternative for formocresol in pulpotomy of deciduous teeth.     

Analysis of apoptosis and expression of genes related to apoptosis in cultures of follicles derived from vitrified and non-vitrified ovaries

The aim of this study was to evaluate the incidence of apoptosisafter in vitro culture of isolated follicles derived from vitrifiedand non-vitrified ovaries. Mouse ovaries were vitrified andtheir pre-antral follicles were mechanically isolated and culturedfor 10 days. Growth and survival rates of the follicles wereassessed during the culture period and the ultrastructure ofthe follicles was studied. The expression of p53, Bcl-2, Bax,Fas, FasL and survivin were analyzed by real-time RT–PCRin different follicular developmental stages. The percentagesof apoptotic and necrotic cells were determined using a fluorescein-activatedcell sorting (FACS) technique. There were no differences betweenthe growth and survival rates of follicles in the vitrifiedand non-vitrified groups. All of the evaluated genes were expressedin the pre-antral, large pre-antral and antral follicles inboth groups, except Fas mRNA, which was not expressed in thepre-antral follicles. The expression of p53, Bcl2, Bax and FasLmRNA was similar in vitrified and non-vitrified groups; however,Fas mRNAs were more strongly expressed in the antral folliclesof the vitrified group than of the control group (P < 0.05).The expression of survivin 140 was lower in the antral folliclesof the vitrified group than of the control group (P < 0.05).FACS analysis showed that the percentage of intact cells waslower in the vitrified group than in the non-vitrified group(P < 0.05). This study demonstrated no signs of apoptosisultrastructurally in cultured follicles; however, vitrificationwas shown to affect the expression of some genes related toapoptosis.     

Attachment and Penetration of Acyclovir‐resistant Herpes Simplex Virus are Inhibited by Melissa officinalis Extract

Medicinal plants are increasingly of interest as novel source of drugs for antiherpetic agents, because herpes simplex virus (HSV) might develop resistance to commonly used antiviral drugs. An aqueous extract of Melissa officinalis and the phenolic compounds caffeic acid, p‐coumaric acid and rosmarinic acid were examined for their antiviral activity against herpes simplex virus type 1 (HSV‐1) acyclovir‐sensitive and clinical isolates of acyclovir‐resistant strains in vitro. When drugs were added during the intracellular replication of HSV‐1 infected cells, no antiviral effect was observed by plaque reduction assay. However, Melissa extract interacted directly with free viral particles of two acyclovir‐resistant HSV strains at low IC₅₀ values of 0.13 and 0.23 µg/mL and high selectivity indices of 2692 and 1522, respectively. The Melissa extract and rosmarinic acid inhibited HSV‐1 attachment to host cells in a dose‐dependent manner for acyclovir‐sensitive and acyclovir‐resistant strains. These results indicate that mainly rosmarinic acid contributed to the antiviral activity of Melissa extract. Penetration of herpes viruses into cells was inhibited by Melissa extract at 80% and 96% for drug‐sensitive and drug‐resistant viruses, respectively. Melissa extract exhibits low toxicity and affects attachment and penetration of acyclovir‐sensitive and acyclovir‐resistant HSVs in vitro. Copyright © 2014 John Wiley & Sons, Ltd.