65 research outputs found

    The Impact of Aspect Ratio, Characteristic Strength and Compression Rebars on the Shear Capacity of Shallow RC Beams

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    This paper investigates the impact of the aspect ratio, the characteristics strength of the concrete, and the compression steel ratio on the shear capacity of wide-shallow beams. An experimental program consists of seven specimens, including a control specimen, all tested under a three-point load test. Three specimens were considered for each parameter (the control specimen was included in all three variables). The experimental results were compared to the theoretical values of six different codes of practice; they were also analyzed to determine the ductility, stiffness, and dissipated energy of each specimen. The results indicated that the shear reinforcement was fully functioning until it yielded, with a minimum contribution of 55% of the total shear capacity of the specimens. The aspect ratio and the characteristic strength had a notable impact on the shear capacity of the specimens, while the compression steel ratio had a minor effect on the shear capacity, but it improved the stiffness and the ductility of the beams. Theoretical concrete shear strengths from design codes ranged between 77 and 163% of the experimental values; EN-1992 was the closest code to the experimental results. A comparison between the experimental results and predicted values using GP and EPR methods from previous research showed accuracies of 72% and 81%, respectively. Doi: 10.28991/CEJ-2023-09-09-012 Full Text: PD

    Uloga kompleksa germanija s L-cysteinom i α-tokoferolom kao stimulatora antioksidativnog obrambenog sustava štakora izloženih gama-zračenju

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    This study was conducted to evaluate the potency of the newly prepared germanium L-cysteine α-tocopherol complex [germanium dichloro tetrakis (L-cysteinyl-α-tocopherol amide) dichloride] as a protective agent against γ-irradiation-induced free radicals production and liver toxicity. Male Swiss albino rats were injected intraperitoneally with the germanium complex in a concentration of 75 mg kg-1 body mass per dose, for 6 successive doses, last dose administered twenty minutes pre-exposure to a single dose of whole body γ-irradiation of 6.5 Gy. Lipid peroxidation (LPx), nitric oxide (NO), glutathione (GSH) levels, and activity of the antioxidant enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were estimated in blood and liver, and blood total protein, cholesterol, triglyceride and α-tocopherol content were estimated as well. The results revealed that administration of germanium complex pre-irradiation resulted in significant (p < 0.001) improvement compared to the irradiated group in the level of hepatic and blood LPx. Hepatic GSH revealed a significant increase (p < 0.001), while its level showed no significant variation in blood. Also, the level of NO in blood and liver increased significantly (p < 0.001). On the other hand, pretreatment with the germanium complex normalized the activities of SOD, GPx and CAT in blood and liver when compared to the irradiated group. The study also documents a marked decrease in the blood triglyceride and cholesterol (p < 0.001); and significant increase (p < 0.001) of -tocopherol and total protein contents in blood. These biochemical changes were associated with marked improvement of histological status. Therefore, the germanium L-cysteine α-tocopherol complex may be a good candidate for ameliorating the changes induced by irradiation, which indicates the beneficial radio-protective role of this antioxidant agent.U radu je procjenjivan kompleks germanija s L-cisteinom i α-tokoferolom [germanijev diklortetrakis (L-cisteinil-α-tokoferol amid) diklorid] kao zaštitno sredstvo protiv slobodnih radikala induciranih γ-zračenjem hepatotoksičnosti. Mužjacima švicarskih albino štakora davan je intraperitonealno kompleks germanija, u 6 sukcesivnih doza po 75 mg kg-1 tjelesne mase, posljednja doza dana je dvadeset minuta prije izlaganja cijelog organizma jednokratnoj dozi γ-ozračivanja od 6,5 Gy. U krvi i jetri praćena je razina lipidne peroksidacije (LPx), dušikovog(II) oksida (NO), glutationa (GSH), aktivnost antioksidativnih enzima glutation peroksidaze (GPx), superoksid dismutaze (SOD) i katalaze (CAT), te količina ukupnih proteina u krvi, kolesterola, triglicerida i α-tokoferola. Rezultati su pokazali da je primjena germanijevog kompleksa značajno (p < 0,001) poboljšala koncentraciju jetrenih i krvnih LPx. Koncentracija GSH u jetri je značajno porasla (p < 0,001), dok se njegova razina u krvi nije značajno promijenila. Koncentracija NO u krvi i jetri značajno se smanjila (p < 0,001). S druge strane, prethodna obrada s kompleksom germanija normalizirala je aktivnost SOD, GPx i CAT u krvi i jetri u odnosu na ozračenu skupinu. Istraživanja su također pokazala značajno smanjenje triglicerida i kolesterola (p < 0,001) i značajno povećanje (p < 0,001) alfa-tokoferola i ukupnih proteina u krvi. Te biokemijske promjene su povezane s izraženim poboljšanjem histoloških promjena u odnosu na ozračenu skupinu. Opisani kompleks germanija mogao bi se kao antioksidativno sredstvo potencijalno upotrijebiti za spriječavanje promjena uzrokovanih zračenjem

    Pertussis seroimmunity in mother-neonate pairs and other pediatric age groups from Egypt

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    Background: Despite the widespread availability of 2 classes of effective vaccines, whole cell and acellular, pertussis has resurged as a serious public health problem. We sought to investigate the pertussis immune status of mother-neonate pairs and children in our country where pertussis vaccination is obligatory. Methods: This cross-sectional study included 75 healthy full-term neonates and their mothers, 100 infants (2-24 months), 170 children (2-12 years) and 80 adolescents (12-18 years). Serum pertussis IgG was measured in all enrolled subjects. A positive titre was defined as &gt;24 U/ml. Results: Positive pertussis IgG levels were detected in 69 of the mothers (92%), in 63 of their newborns (84%). Seroimmunity to pertussis was positively noted in 55% of infants, 82.2% of preschool children, 77.5% of school-aged children and 75% in adolescents. Serum pertussis IgG titers among the neonates showed a significant positive correlation with the maternal titers (P=0.00001). Higher rates of pertussis seroimmunity was observed among residents in urban and suburban areas as compared to those living in rural areas (P&lt;0.05) . Conclusion: This pilot study may suggest the presence of sufficient pertussis seroimmunity rates in the studied age groups. Still, there were some failures in immune acquisition probably due to inefficient vaccination in some localities or waning of immunity with age. Wider scale studies would allow better insight into the pertussis immune status in our country and hence the need for booster immunization

    Interferon gamma: is it a co-player in the pathogenesis of idiopathic nephrotic syndrome

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    Introduction: Idiopathic nephrotic syndrome (INS), the most common form of NS in childhood, was considered 4 decades ago as a systemic disorder of T cells, mediated through its released cytokines. To date, the exact incriminated cytokine or immunological mediator is not properly defined. Interferon gamma (IFN-γ), a pro-inflammatory cytokine, is thought to have a role in the provocation of the T cell mediated INS relapse, through promotion of T helper1 (Th1) differentiation and suppression of regulatory T cells (Treg). Aim of the study: to evaluate the immunopathogenic role of IFN-γ in children with steroid sensitive idiopathic nephrotic syndrome (SSNS) through monitoring the changes in its levels with disease course. Methods: This study included twenty-five newly diagnosed children with SSINS. They were all given full dose prednisolone, evaluated at initial diagnosis and at full remission as regards the serum level of IFN-γ. Results: Serum levels of IFN-γ were lowermost at time of diagnosis and increased with remission on corticosteroids. Conclusions: this study points to a role for the lower serum IFN-γ at diagnosis, in the immunopathogenesis of INS than at remission and the rise in its serum level might be a marker of remission induction, however this awaits confirmation in larger scale studies. Studies on renal biopsy specimens are needed to determine the exact renal in situ levels and effects of IFN-

    Subclinical hypothyroidism among Egyptian children with systemic lupus erythematosus

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    Background: Thyroid autoimmune diseases have been associated with systemic lupus erythematosus (SLE). Both hypothyroidism and hyperthyroidism are seen, but hypothyroidism is the most common abnormality. Subclinical hypothyroidism (SCH) has been reported among adult lupus patients. SCH is not without risk as it might contribute to a proatherogenic state. Objectives: This study was aimed to assess the frequency of SCH in a group of Egyptian children with SLE and its effects on the serum lipids. Methods: Forty patients with pediatric SLE who regularly follow up at our center were enrolled in this study. They were subjected to routine laboratory investigations of SLE and measurement of serum lipids (serum triglycerides, cholesterol, LDL and HDL) as well as free thyroxine (T4), thyroid stimulating hormone (TSH) and anti-thyroperoxidase antibody (anti-TPO-ab) titre. SLE activity was assessed using the systemic lupus erythematosus disease activity index (SLEDAI). Results: Six patients (15%) were found to have SCH while the remaining 34 patients (85%) had normal thyroid function. Anti-TPO-abs were positive in 4 out of the 6 (66.6 %) SLE patients with SCH and in 20 out of the 34 (58.8%) SLE patients with normal thyroid function. In SLE patients with SCH, TSH correlated positively yet insignificantly with anti-TPO-ab titre and the duration of SLE (p = 0.17, p = 0.12, respectively). There were no statistically significant correlations between the serum lipids of SLE patients with SCH and their thyroid function or anti-TPO-ab titre. Conclusion: SCH is not uncommon among children with SLE. This SCH does not seem to affect serum lipids. However, further longitudinal studies on wider scales are needed to assess the long term effects of SCH in those patients.Keywords: SLE, anti-thyroperoxidase antibodies, subclinical hypothyroidismEgypt J Pediatr Allergy Immunol 2011;9(2):87-9

    Respiratory Viruses and Atypical Bacteria Co-Infection in Children with Acute Respiratory Infection

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    BACKGROUND: Acute respiratory infections (ARI) are one of the prevalent pediatric diseases. Coinfections of respiratory viruses and atypical bacterial respiratory pathogens are common.AIM: This study aimed to determine the prevalence of co-infection between respiratory pathogens including viruses, bacteria and atypical bacteria in a sample of Egyptian children presenting with symptoms of acute respiratory tract infection.METHODS: This one-year prospective cohort study conducted in Abo El Rish Pediatric Hospital, Cairo University over one year included children presenting with symptoms of acute respiratory infection. Enrolled children were subjected to nasopharyngeal swabs or throat swabs and then processed to detect viral, bacterial and atypical bacterial causative agents by culture), retrotranscription polymerase, Monoplex polymerase chain reaction (PCR) and Multiplex PCR.RESULTS: Viral etiological agents were detected in 20 cases (20.8%), while 76 patients (79.2%) had no definite viral aetiology. The most abundant virus detected was Rhinovirus in 36 (27.3%), followed by 21 (15.9%) were positive for RSV, 12 (9.1%) were positive for HMPV, 6 (4.5%) were positive for adenovirus and 3 (2.3%) were positive for influenza B. For Atypical bacterial causes Mycoplasma were positive for 9 (6.8%) cases and one case was positive for Bordetella parapertussis. Viral and atypical bacteria Co infection were detected in 14 (10.6%) of cases.CONCLUSION: These results suggest that coinfection with bacteria or atypical bacteria in children with acute respiratory tract infection is common and this co-infection can induce serious illness. The multiplex reverse-transcriptase polymerase chain reaction should become an essential tool for epidemiological studies and can fill the gap between clinical presentation and definitive diagnosis

    Detection of Cancer Stem Cells in Colorectal Cancer: Histopathological and Immunohistochemical Study

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    BACKGROUND: Growing evidence supports the notion that the onset of tumorigenesis could occur through cancer stem cells (CSCs). These tumour cells show low proliferative rates, high self-renewal capacity, propensity to differentiate into active proliferating tumour cells &amp; resistance to chemoradiotherapy thus, possibly causing local recurrences &amp; metastasis formation. CD44 has been used as a marker to isolate CSCs from colorectal carcinoma (CRC).AIM: To investigate the immunohistochemical expression of cancer stem cells marker (CD44) in CRC and correlate its expression with the clinicopathological aspects, TNM staging and modified Dukes’ classification.MATERIALS AND METHODS: Tumour biopsies from colectomy specimens of 60 patients with CRC were stained with hematoxylin-eosin for histological evaluation then immunostained with monoclonal antibodies against CD44 which was detected in term of negative or positive expression.RESULTS: CD44 was demonstrated in 58.3% (35/60) of cases and showed statistically significant correlation with tumour site and histological type (p-value &lt; 0.05). However, CD44 showed statistically insignificant inverse correlation with tumour invasiveness (T), lymph node status (N), grade, TNM stage grouping and modified Dukes’ classification, while it was directly correlated with distant metastasis (M) (p-value &gt; 0.05). Chi-square /Fisher exact test proportion independence and the p-value are set significant at 0.05 level.CONCLUSION: the CD44 rate of expression is higher in the colon than rectum and in adenocarcinoma than mucinous and undifferentiated carcinoma. CD44 showed statistically insignificant relation with T, N, M, grade, TNM stage grouping and modified Dukes’ classification

    Genome-Wide Association Studies of the PR Interval in African Americans

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    The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n = 6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was performed for 2.8 million single nucleotide polymorphisms (SNPs) using combined YRI and CEU HapMap phase II panels. We observed a strong signal (rs3922844) within the gene encoding the cardiac sodium channel (SCN5A) with genome-wide significant association (p<2.5×10−8) in two of the four cohorts and in the meta-analysis. The signal explained 2% of PR interval variability in African Americans (beta  = 5.1 msec per minor allele, 95% CI  = 4.1–6.1, p = 3×10−23). This SNP was also associated with PR interval (beta = 2.4 msec per minor allele, 95% CI = 1.8–3.0, p = 3×10−16) in individuals of European ancestry (n = 14,042), but with a smaller effect size (p for heterogeneity <0.001) and variability explained (0.5%). Further meta-analysis of the four cohorts identified genome-wide significant associations with SNPs in SCN10A (rs6798015), MEIS1 (rs10865355), and TBX5 (rs7312625) that were highly correlated with SNPs identified in European and Asian GWA studies. African ancestry was associated with increased PR duration (13.3 msec, p = 0.009) in one but not the other three cohorts. Our findings demonstrate the relevance of common variants to African Americans at four loci previously associated with PR interval in European and Asian samples and identify an association signal at one of these loci that is more strongly associated with PR interval in African Americans than in Europeans

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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