EXPERIMENTAL SHEAR RESISTANCE EVALUATION OF ORDINARY AND PERFOBOND Y-SHAPED SHEAR CONNECTORS

Composite structures refer to two load carrying structural members that are integrally connected and deforming as a single unique unit using shear connectors. The use of shear connectors enhances the development of longitudinal shear forces at the steel-concrete interface. The objective of this research is to study the structural behavior of a proposed separated Y-shaped shear connector. The suggested investigated Y-shaped shear connector is intended to be an improvement to the structural response of the conventional perfobond shear connector. Accordingly, this paper carries out six push-out tests on the separated Y-shaped shear connector according to EC4. The experimental work is performed in the Reinforced Concrete and Heavy Structures Laboratory at the Structural Engineering Department, Tanta University, Egypt. The key parameters affecting the behavior of the shear connector in the current investigation are the height, the thickness and the Y-shaping of the shear connector. Also, the effect of hole existence is investigated. Other parameters such as the length of the connector, the concrete strength and the slab geometry are kept the same for all specimens. Based on the performed tests, the results show that the proposed separated Y-shaped shear connector has higher shear resistance than that of the conventionalperfobond shear connector. Also, the proposed connector shows better ductile behavior than the conventional perfobond connector. Moreover, results proved that increasing the connector thickness has a significant effect on the connector behaviour by increasing its shear resistance. Furthermore, as the height of the connector increases, the shear capacity increases. Finally, from the presented results it is clarified that the proposed separated Y-shaped connector is better and more economical than the conventional perfobond connector

Mycobacterial CYP121 as a target for anti-TB drug discovery

Despite the introduction of the first line treatment regimen forty years ago and the continuous trials since that time to introduce new regimens, tuberculosis (TB) is considered to be the cause of considerable mortality worldwide. Recent research highlighted the Mycobacterium tuberculosis (Mtb)CYP450s as potential drug targets. This article reviews mycobacterial CYP121 as a target for anti-TB drug discovery

Effect of anatomical variability in brain on transcranial magnetic stimulation treatment

Transcranial Magnetic Stimulation is a non-invasive clinical therapy used to treat depression and migraine, and shows further promise as treatment for Parkinson’s disease, Alzheimer’s disease, and other neurological disorders. However, it is yet unclear as to how anatomical differences may affect stimulation from this treatment. We use finite element analysis to model and analyze the results of Transcranial Magnetic Stimulation in various head models.A number of heterogeneous head models have been developed using MRI data of real patients, including healthy individuals as well as patients of Parkinson’s disease. Simulations of Transcranial Magnetic Stimulation performed on 22 anatomically different models highlight the differences in induced stimulation. A standard Figure of 8 coil is used with frequency 2.5 kHz, placed 5 mm above the head. We compare cortical stimulation, volume of brain tissue stimulated, specificity, and maximum E-field induced in the brain for models ranging from ages 20 to 60. Results show that stimulation varies drastically between patients of the same age and health status depending upon brain-scalp distance, which is not necessarily a linear progression with age

What the future holds for regenerative endodontics: novel antimicrobials and regenerative strategies

Regenerative/revitalisation endodontic techniques are increasingly used as a treatment approach for the management of immature permanent teeth with necrotic pulps. Different chemical irrigants and medicaments are routinely used clinically for intra-canal disinfection. However, despite remarkable progress in this field, coronal discolouration, cell cytotoxicity, difficulty of removal of organic biofilm from the root canal, development of sensitisation and antimicrobial resistance are still challenges to this line of treatment. This review critically discusses and challenges the current status quo of antimicrobials used in regenerative endodontics and sheds the light on future alternative antimicrobial materials with regenerative potential

Breast Milk Macronutrients in Relation to Infants’ Anthropometric Measures

BACKGROUND: Breast milk (BM) is the main nutritional source for newborns before they are capable to eat and consume other foods. BM has carbohydrates, lipids, complex proteins, and other biologically active components which have a direct effect on infant growth. AIM: The aim of the study was to correlate anthropometric data of the infant to macronutrients in BM (fat, protein, and carbohydrates) and to find some modifiable issues affecting macronutrient contents of BM for the benefits of upcoming infants. METHODS: One hundred breastfeeding mothers participated in the study, they were recruited from the outpatient clinic, El Demerdash Hospital, Ain Shams University, from September 2019, to December 2019. BM was expressed by an electric pump, macronutrient content was assessed. Anthropometric data of the babies and mothers were obtained, gestational age, parity, age of the women, and the route of birth were recorded. RESULTS: For the macronutrients content of milk, a positive significant correlation was observed between BM fat, protein, and lactose. Infants’ body mass index (BMI) was negatively related to the fat content of BM, while no relation was found between BMI and protein or lactose content of the milk. BM fat content was negatively correlated with gestational age and maternal age. Positive correlations were found between BMI and protein, lactose and infant age. Protein content was negatively correlated with parity. No impact of infant’s sex on BM composition and as regards maternal diet, high protein consumption leading to increase BM protein content. CONCLUSIONS: The current study confirms that BM macronutrient composition has a wide variability; this variability is associated with each macronutrient, respectively. To improve BM composition, one could aim for improving the nutritional balance in lactating women, especially for protein intake. More well-designed longitudinal studies about factors that influence human milk compositions are warranted

Mycobacterial CYP121 as a target for anti-TB drug discovery

Despite the introduction of the first line treatment regimen forty years ago and the continuous trials since that time to introduce new regimens, tuberculosis (TB) is considered to be the cause of considerable mortality worldwide. Recent research highlighted the Mycobacterium tuberculosis (Mtb)CYP450s as potential drug targets. This article reviews mycobacterial CYP121 as a target for anti-TB drug discovery

Chemical Profiling of Significant Antioxidant and Phytotoxic Microwave-Extracted Essential Oil from Araucaria heterophylla Resin

Due to the various hazards of using synthetic chemical compounds in pharmaceutics, agriculture, and industry, scientists and researchers do their best to explore and assess new green natural compounds from natural resources with potent activity. The essential oil (EO) from the resin collected from Araucaria heterophylla Salisb. was extracted by the microwave technique and chemically characterized via GC-MS analysis. Furthermore, the extract EO was assessed for its antioxidant and phytotoxic activities. The EO has 33 compounds, mainly terpenes (98.23%), and the major compounds were α-pinene (62.57%), β-pinene (6.60%), germacrene D (5.88%), and β-caryophyllene (3.56%). The extracted EO showed substantial antioxidant activity, where it showed IC50 values of 142.42 and 118.03 mg L−1 for DPPH and ABTS, respectively. On the other hand, the EO revealed considerable phytotoxicity against the weed Chenopodium murale, where the EO showed IC50 values of 304.0, 230.1, and 147.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. Moreover, the EO showed the same pattern of allelopathic inhibition against the weed Sonchus oleraceus, where it showed IC50 values of 295.7, 224.5, and 106.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. The present study showed that the extraction technique affects the constituents of the EO, particularly the quantitative composition. The EO of A. heterophylla resin also revealed considerable antioxidant and phytotoxic activity against weeds. Therefore, it can be considered a promising natural resource that could be integrated into the weed management approach. However, further study is recommended for deep characterization of their authentic compounds and evaluation of their mode of action(s) on a wide spectrum of weeds