Softening Coefficient of Reinforced Concrete Elements Subjected to Three-Dimensional Loads

Reinforced concrete structures are prone to fail under the effect of complex threedimensional loading conditions. Accurate constitutive models for concrete under the effect of triaxial stresses are therefore necessary in order to predict the proper response. Strong interaction between in-plane and out of plane shear loads has been observed in experimental tests of concrete structures. This paper presents the derivation of concrete constitutive laws under the effect of triaxial stresses, in particular the softening coefficient, using the results of large-scale tests on representative concrete panels. The experimental program of 7 full-scale panel specimens is briefly described, and the results are then used to derive analytical expressions for the softening coefficient under the effect of bi-directional shear. Finally, existing membrane shear theories are modified to take into consideration the effect of applied out-of-plane shear. The response of the tested panels proved to be accurately predicted using the new theory

Behavior of Reinforced Concrete Membrane Elements Subjected to Bidirectional Shear Loads

The shear design and behavior of a typical membrane reinforced concrete (RC) element has been extensively studied in the past several decades. Such design requires knowledge of the constitutive behavior of RC elements subjected to a shear stress acting along its plane (in-plane shear). These constitutive models were accurately derived from experimental test data on representative RC panel elements. The true behavior of many large, complex structures, however, involves interaction between the in-plane and out-of-plane shear stresses acting on the RC element. To investigate this interaction, large-scale tests on representative concrete panels need to be conducted. The University of Houston is equipped with a unique universal panel testing machine that was used for this purpose. The panel tester enhanced the understanding of the in-plane shear behavior of RC elements. Recently, 10 additional hydraulic jacks were mounted in the out-of-plane direction of the universal panel tester to facilitate testing of concrete elements subjected to bidirectional and tridirectional shear stresses. The experimental program included designing, fabricating, instrumenting, and testing full-scale RC elements. The elements were subjected to different combinations of in-plane and out-of-plane shear loads. A strong interaction between in-plane shear strength and out-of-plane shear stresses was observed

A new stilbene from Agonis flexuosa leaves and verification of its histamine release inhibitory activity using in silico and in vitro studies

This study aimed to explore the phytoconstituents of Agonis flexuosa, F. Myrtaceae and its biological activity. A thorough phytochemical investigation of its leaves led to the isolation of one new stilbene glycoside; (Z)-2,3-dihydroxystilbene-5-O-β-D-glucoside (1), and fifteen known compounds identified as two stilbenes: (Z)-pinosylvin mono methyl ether (2) and (Z)-pinosylvin-3-O-β-D-glucoside (3); six flavanones: (2S)-pinostrobin (4), (2S)-strobopinin (5), (2S)-cryptostobin (6), (2S)-pinocembrin (7), (2S)-dimethylpinocembrin (8) and (2S)-dimethylstrobopinin (9); four flavonoids: quercetin (10), kaempferol-7-O-β-D-glucoside (11), quercetin-3-O-α-D-rhamnoside (12) and quercetin-3-O-β-D-glucoside (13), α-terpineol (14), β-sitosterol (15) and gallic acid (16). The structures of the isolated metabolites were elucidated based upon the interpretation of their 1D and 2D NMR (One Dimensional and Two-Dimensional Nuclear Magnetic Resonance), HR-ESI-MS (High Resolution Electrospray Ionization Mass Spectrometry) and optical rotation. All the isolated compounds were evaluated for their antimicrobial activities. Only compound (6) showed a selective activity against P. aeruginosa with IC50 value of 4.88 µM. In silico virtual screening was done for the isolated compounds on Human histamine H1 receptor (3RZE) downloaded from protein data bank. All the compounds showed certain degree of binding to the protein displaying free binding energies ranging between -11 to -31 kcal/mol. (Z)-2,3-Dihydroxystilbene-5-O-β-D-glucoside (1) showed notable fitting to the active site as evidenced by its free binding energy (∆G) which is computed as -25.09 kcal/mol comparable to diclofenac that displayed (∆G) of -15.00 kcal/mol. In vitro assessment of histamine release inhibitory activity was performed using U937 human monocytes. Compound (1) showed a substantial inhibition to histamine release displaying IC50 value of 0.16 μM

Adverse effects of energy drink on rat pancreas and the therapeutic role of each of bone marrow mesenchymal stem cells and Nigella Sativa oil

Background: Energy drinks have been observed to threaten public health leading to many medical problems. Bone marrow-derived mesenchymal stem cells (BMSCs) have broad prospects in tissue regeneration. Nigella Sativa (NS) possess great therapeutic properties for the treatment of a wide range of diseases. Materials and methods: Forty adult male albino rats were divided into: control group and treated group. The treated group was further subdivided into: energy drink subgroup 2a, BMSCs-injected subgroup 2b, NS-injected subgroup 2c. Histological, immunohistochemical and biochemical assessment was performed. Results: Administration of energy drink revealed that it adversely affected the pancreatic cytoarchitecture. BMSCs and NS have been similarly observed to significantly ameliorate the histological, biochemical and immunohistochemical changes induced by energy drink. Conclusions: The extent of pancreatic regeneration, exerted by each of BMSCs and NS oil, is nearly similar but the effect of BMSCs is more superior; however, NS could be privileged to BMSCs as a line of treatment being easily accessible and of lower cost

Impact of Nutritional Health Education on Knowledge and Practices of Mothers of Anemic Children in El Othmanyia Village – Egypt

BACKGROUND: In Egypt, more than one in four children suffers from some degree of anemia. AIM: This study was carried out to assess and improve the nutritional knowledge and risky nutritional habits of the mothers of anemic children aged 2–12 years old in El Othmanyia village. MATERIALS AND METHODS: An interventional study was conducted among anemic children aged 2–12 years old and their mothers in El Othmanyia village, Egypt. The study passed through three stages over 1 and ½ years; pre-interventional assessment of awareness (n = 350), educational interventions targeting anemic children and their mothers, and post-interventional evaluation of change in awareness and practice. RESULTS: The mean knowledge % score of mothers increased significantly after the intervention (82.2 ± 14.2 vs. 6.3 ± 5.8, respectively). Furthermore, the mean hemoglobin of the studied children increased significantly after the intervention (11.1 ± 0.7 vs. 10.5 ± 0.7). The percent of children with anemia decreased significantly from 100% to 40.3% after the intervention (p < 0.001). CONCLUSION: The knowledge and practices of mothers are moving in a desirable direction after the health education intervention. Hence, nutrition education is an appropriate, effective, and sustainable approach to combat iron deficiency anemia. Recommendations: A multiple interventional strategies between different ministries to set policies and guidelines that support the healthy nutritional behavior among children are recommended. &nbsp

Effect of Tramadol on the Development of Chick Embryos

Tramadol acts as a synthetic analgesic agent used to treat moderate to severe pain. The present study was designed to determinate the possible hazard effects of tramadol on the morphology of chick embryo and amniotic fluid biochemical changes. 240 Fertile chicken eggs were injected into the air sac with doses of 12.5,25,50 and 100 mg /kg egg wt, respectively, after 24 hr of incubation. Embryos were examined at 4 intervals on days 3, 6, 12, and 18 of incubation. Treated embryos showed an increase in mortality rates, growth retardation and many congenital malformations such as growth retardation, enlargement in the head region, and incomplete embryonic development on 3 days of incubation. Brain exencephaly, hematoma, acephaly, and ectopiacordis in 6 days of incubation. Undeveloped beak, reduced external auditory aperture and ectopia visceral were seen in 12-day treated embryos. While 18-day treated embryos exhibited oedema, anophthalmia, absence of feathers and limb deformities. Tramadol induced significant biochemical changes in the amniotic fluid including elevation in aspartate and alanine aminotransferases (AST and ALT), alkaline phosphatase (ALP), sodium (Na), creatinine and urea besides reduction in the total protein, potassium (K), calcium (Ca), phosphorus (Ph) and total antioxidant capacity (TAC) when compared to control groups. Tramadol has an embryotoxic effect, as shown by an increase in congenital abnormalities and a considerable modification of some amniotic fluid biochemical parameters Therefore, it is recommended that tramadol should be taken only with the prescription of doctor and self-medication of this medicine may be hazardous

Derivation and comparison of formulae for the adjustment of total calcium

Background: Free ionized calcium (Ca2+) is the biologically active component of total calcium (TCa) and hence responsible for its biological action. TCa is routinely adjusted for albumin using several formulae (e.g. James, Orell, Payne and Berry) to more closely reflect Ca2+. Here, we derive a novel formula to estimate Ca2+ and compare its performance to established formulae. Methods: Cohort for prediction of Ca2+: 2806 serum samples (TCa) taken contemporaneously with blood gas samples (Ca2+) at Imperial College Healthcare NHS Trust were used to derive formulae to estimate Ca2+ using multivariable linear regression. Cohort for prediction of PTH: Performance of novel and existing formulae to predict PTH in 5510 patients was determined by Spearman correlation. Results: Ca2+ prediction Cohort: Adjusted calcium (r2 = 0.269) was less strongly associated with Ca2+, than TCa (r2 = 0.314). Prediction of Ca2+ from a newly derived formula incorporating TCa, potassium, albumin, and hematocrit had an improved r2 of 0.327, whereas inclusion of all available parameters increased the r2 further to 0.364. Of the established formulae, James performed best in predicting Ca2+ (r2 = 0.27). PTH prediction cohort: Berry resulted in higher whereas Orell in lower adjusted calcium levels. Prediction of PTH was strongest in the setting of hypercalcemia, with James having the highest Spearman correlation coefficient (+0.496) similar to including all parameters (+0.499). Conclusion: Adjustment of calcium for albumin using established formulae does not always outperform unadjusted TCa in the reflection of Ca2+. Further prospective studies are needed to optimise adjustment of TCa and to establish bounds for validity

Stability of Immediately Placed and Delayed Implants Using Resonance Frequency Analysis (RFA). A Systematic Review

Objectives: The aim of the present Systematic Review was to compare between immediate and delayed dental implant placement using resonance frequency analysis specifically Implant Stability Quotients (ISQ). Search methods: Search was performed in two databases (PubMed and Cochrane Library) till March 2023. Randomized clinical trials (RCTs) were included and measurements of ISQ at time of placement and time of loading were recorded. We excluded papers discussing bone grafting, orthodontic treatment and implant surface treatment. Results: Results were above ISQ threshold value of 65, with no significant difference between immediate and delayed implants. However, Immediate placement showed shorter treatment time and better esthetic outcome. Conclusion: Implant stability can be achieved with both immediate and delayed implant placement techniques