A mechanical behavior law for the numerical simulation of the mushy zone in welding

The aim of this work is to propose a mechanical behavior law dedicated to the mushy zone located between the solid phase and the weld pool in welding. The objective is to take into account of the influence of the mushy zone in the simulation of welding in order to improve the computation of induced effects such as residual stresses

In vitro Activity of the Aqueous Extract of the Plant Kigelia africana Against Theileria lestoquardi

The objective of this study was to test the activity of the aqueous extract of the plant Kigelia africana against Theileria lestoquardi, the causative agent of malignant ovine theileriosis. Aqueous extract of K. africana fruits was screened for its in vitro activity against T. lestoquardi at different concentrations of 250, 500, 5000 and 10000 ppm. Lymphocytes infected with T. lestoquardi were isolated from heparinized blood with Ficoll-paque, grown in minimum essential medium and continuously sub cultured until passage 8 which was used for the test. The parasite was identified, using indirect fluorescent antibody test. The results revealed in vitro activities of 20%, 58% and 80% at concentrations of 500, 5000 and 10000 ppm, respectively. Lethal dose 50% and 99% (LC50 and LC99) were 2660.28 and 29980.34 ppm, respectively. The extract activity caused significantly (P≤0.05) high death of macroschizonts, decrease in the number of macroschizonts per cell, and increase in the number of extra cellular macroschizonts at concentrations of 5000 and 10000 ppm. The number of dividing cells significantly (P≤0.05) decreased at concentrations of 500, 5000 and 10000 ppm. The number of viable cells, also, significantly (P≤0.05) decreased at concentrations of 5000 and 10000 ppm compared with the control which did not significantly (P>0.05) increase. Besides, the activity of the highest concentration (10000 ppm) revealed some lymphoblast cells with degenerated nuclei. The study showed that K. africana has antitheilerial effect on T. lestoquardi and could be an effective candidate for the treatment of malignant ovine theileriosis after in vivo confirmation. Further studies are recommended for phytochemical analysis and mode of action

Recent Outbreaks of Rift Valley Fever in East Africa and the Middle East

Rift Valley fever (RVF) is an important neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health. Mosquitoes in the Aedes genus have been considered as the reservoir, as well as vectors, since their transovarially infected eggs withstand desiccation and larvae hatch when in contact with water. However, different mosquito species serve as epizootic/epidemic vectors of RVF, creating a complex epidemiologic pattern in East Africa. The recent RVF outbreaks in Somalia (2006–2007), Kenya (2006–2007), Tanzania (2007), and Sudan (2007–2008) showed extension to districts, which were not involved before. These outbreaks also demonstrated the changing epidemiology of the disease from being originally associated with livestock, to a seemingly highly virulent form infecting humans and causing considerably high-fatality rates. The amount of rainfall is considered to be the main factor initiating RVF outbreaks. The interaction between rainfall and local environment, i.e., type of soil, livestock, and human determine the space-time clustering of RVF outbreaks. Contact with animals or their products was the most dominant risk factor to transfer the infection to humans. Uncontrolled movement of livestock during an outbreak is responsible for introducing RVF to new areas. For example, the virus that caused the Saudi Arabia outbreak in 2000 was found to be the same strain that caused the 1997–98 outbreaks in East Africa. A strategy that involves active surveillance with effective case management and diagnosis for humans and identifying target areas for animal vaccination, restriction on animal movements outside the affected areas, identifying breeding sites, and targeted intensive mosquito control programs has been shown to succeed in limiting the effect of RVF outbreak and curb the spread of the disease from the onset

Cytotoxic Activity and Metabolic Profiling of Fifteen Euphorbia Species

Euphorbia is a large genus of flowering plants with a great diversity in metabolic pattern. Testing the cytotoxic potential of fifteen Euphorbia species revealed highest activity of E. officinarum L. against CACO2 cell line (IC50 7.2 µM) and of E. lactea Haw. against HepG2 and MCF-7 cell lines (IC50 5.2 and 5.1 µM, respectively). Additionally, metabolic profiling of the fifteen tested species, using LC-HRMS, for dereplication purposes, led to the annotation of 44 natural compounds. Among the annotated compounds, diterpenoids represent the major class. Dereplication approach and multivariate data analysis are adopted in order to annotate the compounds responsible for the detected cytotoxic activity. Results of PCA come in a great accordance with results of biological testing, which emphasized the cytotoxic properties of E. lactea Haw. A similarity correlation network showed that the two compounds with the molecular formula C16H18O8 and C20H30O10, are responsible for cytotoxic activity against MCF-7 and HepG2 cell lines. Similarly, the compound with molecular formula C18H35NO correlates with cytotoxic activity against CACO2

Effect of pretreatment on the proximate composition, physicochemical characteristics and stability of <em>Moringa peregrina</em> oil

The present research work was intended to study the influence of roasting and germination of the kernel seeds of Sudanese Moringa peregrina on the physicochemical characteristics and the oxidative stability of the extracted oil. Roasting was carried out at 180 ˚C for 25 minutes, whereas germination was done at ambient conditions in a wet jute bag for 5–7 days. The oil was extracted using n-hexane in a Soxhlet extraction apparatus. The results show that the oil contains α-tocopherols (152mg/kg) and oleic acid (above 70%) as the major tocols and fatty acids, respectively. Germination reduced the peroxide value and increased the acid value in a significant way (p < 0.05) whereas the opposite trend was noticed in the case of roasting. It is crucial to note that, with the exception of the acid value of the germinated sample, peroxide and acid values remained below one meq O2/Kg of oil and one mg KOH/g of oil, respectively. The oxidative stability of the oil from the roasted sample was increased almost by 80% compared to the raw one. Roasting of the kernels prior to oil extraction is imperative for improving its oxidation resistance and the physicochemical characteristics

Metabolic profling of cytotoxic metabolites from five Tabebuia species supported by molecular correlation analysis

Tabebuia is the largest genus among the family Bignoniaceae. Tabebuia species are known for their high ornamental and curative value. Here, the cytotoxic potential of extracts from the leaves and stems of fve Tabebuia species was analyzed. The highest activity was observed for T. rosea (Bertol.) DC. stem extract against HepG2 cell line (IC50 4.7 µg/mL), T. pallida L. stem extract against MCF-7 cell line (IC50 6.3 µg/mL), and T. pulcherrima stem extract against CACO2 cell line (IC50 2.6 µg/mL). Metabolic profiling of the ten extracts using liquid chromatography–high-resolution mass spectrometry for dereplication purposes led to annotation of forty compounds belonging to diferent chemical classes. Among the annotated compounds, irridoids represent the major class. Principle component analysis (PCA) was applied to test the similarity and variability among the tested species and the score plot showed similar chemical profling between the leaves and stems of both T. pulcherrima and T. pallida L. and unique chemical profling among T. rosea (Bertol.) DC., T. argentea Britton, and T. guayacan (Seem.) Hemsl. leaf extracts and the stem extract of T. rosea (Bertol.) DC. Additionally, a molecular correlation analysis was used to annotate the bioactive cytotoxic metabolites in the extracts and correlate between their chemical and biological profles

Fracture simulation of viscoelastic membranes by ordinary state-based peridynamics

Despite a load below the elastic limit is applied on a viscoelastic material, the material may fail after a long duration of constant loading because of the time-dependent viscous deformations. ln this regard, a viscoelastic material model in the ordinary statebased peridynamic framework is proposed to capture crack propagation in polymeric water treatment membranes. The defom1at ion state is decoupled into dilatational and distortional parts, and it is assumed that the dilatational part of defom1ation is elastic, while the distortional pru1 is considered as viscoelastic, whose behaviour can be represented by the Prony series. First, we verify our implementation with FEM results for a benchmark case. Afterwards, the crack propagation is studied by the viscoelastic ordinary state-based peridynamic model

Management of Extremity Venous Thrombosis in Neonates and Infants: An Experience From a Resource Challenged Setting

We aimed to evaluate the outcome of different treatment modalities for extremity venous thrombosis (VT) in neonates and infants, highlighting the current debate on their best tool of management. This retrospective study took place over a 9-year period from January 2009 to December 2017. All treated patients were referred to the vascular and pediatric surgery departments from the neonatal intensive care unit. All patients underwent a thorough history-taking as well as general clinical and local examination of the affected limb. Patients were divided into 2 groups: group I included those who underwent a conservative treated with the sole administration of unfractionated heparin (UFH), whereas group II included those who were treated with UFH plus warfarin. Sixty-three patients were included in this study. They were 36 males and 27 females. Their age ranged from 3 to 302 days. Forty-one (65%) patients had VT in the upper limb, whereas the remaining 22 (35%) had lower extremity VT. The success rate of the nonsurgical treatment was accomplished in 81% of patients. The remaining 19% underwent limb severing, due to established gangrene. The Kaplan-Meier survival method revealed a highly significant increase in both mean and median survival times in those groups treated with heparin and warfarin compared to heparin-only group (P < .001). Nonoperative treatment with anticoagulation or observation (ie, wait-and-see policy) alone may be an easily applicable, effective, and a safe modality for management of VT in neonates and infants, especially in developing countries with poor or highly challenged resource settings