124 research outputs found

    The Bond Strength of Structural Lightweight Pumice Aggregate Concrete with/without Silica Fume

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    In this study, the bond strength between concrete and steel reinforcement of structuralconcrete produced by lightweight pumice aggregate (SLWAC) is investigated by comparingwith the normal-weight aggregate (NWAC) without additives. To achieve these objectives, 7different types of concrete mixtures were produced. In producing of the SLWAC mixtures, amineral additive, Silica Fume (SF), was used to replace the Portland cement in the ratios of 0%, 5 % and 10 % by weight. The remaining three types of mixtures were obtained by addingSuper Plasticizers (SP) to the above mixtures in the ratio of 2 % by weight.In conclusion; the use of SF and SP together, increased the bonding between theconcrete and the steel reinforcement in SLWAC. The bond strength of deformed bars inSLWAC was lower compared to those of NWAC. Normalized bond strength of L-5-2 and L-10-2 coded specimens were found to be 1.01 and 1.10 times (with respectively) highercompared to normal weight concrete without additives (R). Other all SLWAC specimens wereless than R (ranges between 0.92 and 0.96 times). Besides, it was also observed that the slip atpeak load for pullout failure of ribbed bar did not vary too much for both NWAC andSLWAC specimens (ranges between 1.0 and 2.3 mm)

    Electromagnetic High-Frequency Transients Measurements of Some Household Devices

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    Voltage Transients are generated in power lines and emit both low-frequency electromagnetic fields and radio-frequency radiation. This study aims to highlight its existence and detrimental effects on human health. A comprehensive literature review is presented, encompassing studies by multiple authors exploring the topic of dirty electricity, its impact on well-being, and preventative measures. The electromagnetic spectrum analysis and measurements of both electric and magnetic fields are performed on various household appliances such as hair dryers, old televisions, blenders, heaters, toasters, vacuum cleaners, and microwaves. The findings indicates that microwaves and compact fluorescent lamps (CFL) bulbs exhibit similar spectral characteristics, with high-frequency voltage transients primarily originating from these two devices. Conversely, other appliances do not generate significant high-frequency voltage transients (HFVT). Overall, dirty electricity poses a substantial risk to human health and necessitates attention to minimize its adverse consequences

    Genetic polymorphism in the serotonin transporter gene-linked polymorphic region and response to serotonin reuptake inhibitors in patients with premature ejaculation

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    OBJECTIVES: Serotonin plays a central role in ejaculation and selective serotonin reuptake inhibitors have been successfully used to treat premature ejaculation. Here, we evaluated the relationship between a polymorphism in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) and the response of patients with premature ejaculation to SSRI medication. METHODS: Sixty-nine premature ejaculation patients were treated with 20 mg/d paroxetine for three months. The Intravaginal Ejaculatory Latency Time and International Index of Erectile Function scores were compared with baseline values. The patients were scored as having responded to therapy when a 2-fold or greater increase was observed in Intravaginal Ejaculatory Latency Time compared with baseline values after three months. Three genotypes of 5-HTTLPR were studied: LL, LS and SS. The appropriateness of the allele frequencies in 5-HTTLPR were analyzed according to Hardy-Weinberg equilibrium using the χ2-test. RESULTS: The short (S) allele of 5-HTTLPR was significantly more frequent in responders than in nonresponders (

    A simple concept for covering pressure sores : wound edge-based propeller perforator flap

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    We present a new surgical modification to allow propeller perforator flaps to cover pressure sores at various locations. We used a propeller perforator flap concept based on the detection of newly formed perforator vessels located 1 cm from the wound margin and stimulated by the chronic inflammation process. Between January 2009 and January 2017, 33 wound edge-based propeller perforator flaps were used to cover pressure sores at various locations in 28 patients. In four cases more than one flap was used on the same patient. The patients comprised 18 males and 10 females with a mean age of 4125 (range, 16-70) years. All patients underwent follow-up for 0-12 months. The mean follow-up duration was 503 months. Venous congestion was observed in three flaps that were rotated by 180 degrees (91%). However, there was a significant difference between flaps rotated by 90 degrees and 180 degrees according to the complication rate (P = 0034). Out of 33 flaps, 29 flaps healed uneventfully. Patients were able to sit and lie on their flaps three weeks after surgery. In our study, we were able to obtain satisfying final results using these novel flaps

    Evaluation of the Oxidative Effect of Long-Term Repetitive Hyperbaric Oxygen Exposures on Different Brain Regions of Rats

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    Hyperbaric oxygen (HBO2) exposure affects both oxidative and antioxidant systems. This effect is positively correlated with the exposure time and duration of the treatment. The present study aims enlightening the relation of HBO2 with oxidative/antioxidant systems when administered in a prolonged and repetitive manner in brain tissues of rats. Sixty rats were divided into 6 study (n = 8 for each) and 1 control (n = 12) group. Rats in the study groups were daily exposed 90-min HBO2 sessions at 2.8 ATA for 5, 10, 15, 20, 30 and 40 days. One day after the last session, animals were sacrificed; their whole brain tissue was harvested and dissected into three different regions as the outer grey matter (cortex), the inner white matter and cerebellum. Levels of lipid peroxidation and protein oxidation and activities of superoxide dismutase and glutathione peroxidase were measured in these tissues. Malondialdehyde, carbonylated protein and glutathione peroxidase levels were found to be insignificantly increased at different time-points in the cerebral cortex, inner white matter and cerebellum, respectively. These comparable results provide evidence for the safety of HBO treatments and/or successful adaptive mechanisms at least in the brain tissue of rats, even when administered for longer periods

    Giant cervicothoracic extradural arachnoid cyst: case report

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    The pathogenesis, etiology, and treatment of the spinal arachnoid cyst have not been well established because of its rarity. A 57-year-old male was presented with spastic quadriparesis predominantly on the left side. His radiological examination showed widening of the cervical spinal canal and left neural foramina due to a cerebrospinal fluid - filled extradural cyst that extended from C2 to T2 level. The cyst was located left anterolaterally, compressing the spinal cord. Through a C4–T2 laminotomy, the cyst was excised totally and the dural defect was repaired. Several features of the reported case, such as cyst size, location, and clinical features make it extremely unusual. The case is discussed in light of the relevant literature

    Wolfram Syndrome: New Mutations, Different Phenotype

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    BACKGROUND: Wolfram Syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, and Deafness identified by the acronym "DIDMOAD". The WS gene, WFS1, encodes a transmembrane protein called Wolframin, which recent evidence suggests may serve as a novel endoplasmic reticulum calcium channel in pancreatic β-cells and neurons. WS is a rare disease, with an estimated prevalence of 1/550.000 children, with a carrier frequency of 1/354. The aim of our study was to determine the genotype of WS patients in order to establish a genotype/phenotype correlation. METHODOLOGY/PRINCIPAL FINDINGS: We clinically evaluated 9 young patients from 9 unrelated families (6 males, 3 females). Basic criteria for WS clinical diagnosis were coexistence of insulin-treated diabetes mellitus and optic atrophy occurring before 15 years of age. Genetic analysis for WFS1 was performed by direct sequencing. Molecular sequencing revealed 5 heterozygous compound and 3 homozygous mutations. All of them were located in exon 8, except one in exon 4. In one proband only an heterozygous mutation (A684V) was found. Two new variants c.2663 C>A and c.1381 A>C were detected. CONCLUSIONS/SIGNIFICANCE: Our study increases the spectrum of WFS1 mutations with two novel variants. The male patient carrying the compound mutation [c.1060_1062delTTC]+[c.2663 C>A] showed the most severe phenotype: diabetes mellitus, optic atrophy (visual acuity 5/10), deafness with deep auditory bilaterally 8000 Hz, diabetes insipidus associated to reduced volume of posterior pituitary and pons. He died in bed at the age of 13 years. The other patient carrying the compound mutation [c.409_424dup16]+[c.1381 A>C] showed a less severe phenotype (DM, OA)
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