Aggregates grain size and press rate dependence of the shielding parameters for some concretes

This study points to evaluate the effect of crushed basalt grain size and the press rate on gamma ray shielding properties for some concretes. Nine different concretes were made up of 75% basalt, 25% Portland cement and drops of sodium meta silicate. Three concretes were performed with an average grain size varied between 25 and 107 μm. The other six concretes were performed under different press rate varied between 1.01 and 142.76 kg/cm2 using a hydraulic press. The mass attenuation coefficient (μm) of the prepared concretes was measured using the narrow beam transmission method using a hyper pure germanium detector at gamma ray energies 661.6, 1173.2, 1332.5, 121.8, 244.7, 344.3, 778.9, 964, 1112, 1408 KeV emitted by point sources 137Cs, 60Co and 152Eu. Other important shielding parameters such as half value thickness and radiation protection efficiency were calculated for the prepared concretes at different energies. The obtained experimental data was compared with theoretical data obtained from XCOM program. The results showed that the mass attenuation coefficient was decreased with energy increase, but it increases with grain size decrease. The obtained results showed also that the mass attenuation enhanced by increasing the pressure rate. © 2019 Elsevier Lt

Time-Fractional KdV Equation: Formulation and Solution using Variational Methods

In this work, the semi-inverse method has been used to derive the Lagrangian of the Korteweg-de Vries (KdV) equation. Then, the time operator of the Lagrangian of the KdV equation has been transformed into fractional domain in terms of the left-Riemann-Liouville fractional differential operator. The variational of the functional of this Lagrangian leads neatly to Euler-Lagrange equation. Via Agrawal's method, one can easily derive the time-fractional KdV equation from this Euler-Lagrange equation. Remarkably, the time-fractional term in the resulting KdV equation is obtained in Riesz fractional derivative in a direct manner. As a second step, the derived time-fractional KdV equation is solved using He's variational-iteration method. The calculations are carried out using initial condition depends on the nonlinear and dispersion coefficients of the KdV equation. We remark that more pronounced effects and deeper insight into the formation and properties of the resulting solitary wave by additionally considering the fractional order derivative beside the nonlinearity and dispersion terms.Comment: The paper has been rewritten, 12 pages, 3 figure

DETERMINATION OF GAMMA RAY ATTENUATION COEFFICIENT OF DIFFERENT TYPES OF BASALTIC ROCKS

Linear and mass attenuation coefficients were studied for basaltic samples from Sinai, Egypt using gamma ray sources 137Cs, 60Co with energies 662, 1173 and 1332 keV.Приведения результаты исследований линейных и массовых коэффициентов ослабления .-излучения 137Cs и 60Co образцами базальта Юго-Западного Синая (Египет) при энергиях 662, 1173 и 1332 кэВ

A rapid and simple single-step method for the purification of Toxoplasma gondii tachyzoites and bradyzoites

This study describes a simple method for the large-scale isolation of pure Toxoplasma gondii tachyzoites and bradyzoites. T. gondii tachyzoites were obtained from infected human foreskin fibroblasts (HFFs) and peritoneal exudates of mice, while tissue cysts containing bradyzoites were collected from chronically infected mice. Harvested cells and brain tissues were incubated in Hanks balanced salt solution (HBSS), containing 0.25% trypsin and 0.5% taurodeoxycholic acid (TDC) for 5 min. Subsequent washes in phosphate buffered saline (PBS) were conducted, and the cell viability of the preparations was good, as determined by flow cytometry and ability to reinfect HFF cells and propagate in mice. The purification procedure allowed for a rapid preparation of pure T. gondii tachyzoites and bradyzoites in sufficient quantity that can be used for downstream procedures. The advantage of the new method is that it is convenient and inexpensive.The National Natural Science Foundation of China (No. 31502071), Youth Innovative Talents Project of Guangdong province Education Department (No. 2017KQNCX212), Guangdong province (2017GDK07), Start-up Research Grant Program provided by Foshan University, Foshan city, Guangdong province for distinguished researchers, Guangdong Science and Technology Plan Project (Grant No: 1244060045607389XC), and School of Life Science and Engineering fund (Grant No: KLPREAD201801-02).http://www.wileyonlinelibrary.com/journal/vms3am2021Paraclinical Science

Plxdc2 Is a Mitogen for Neural Progenitors

The development of different brain regions involves the coordinated control of proliferation and cell fate specification along and across the neuraxis. Here, we identify Plxdc2 as a novel regulator of these processes, using in ovo electroporation and in vitro cultures of mammalian cells. Plxdc2 is a type I transmembrane protein with some homology to nidogen and to plexins. It is expressed in a highly discrete and dynamic pattern in the developing nervous system, with prominent expression in various patterning centres. In the chick neural tube, where Plxdc2 expression parallels that seen in the mouse, misexpression of Plxdc2 increases proliferation and alters patterns of neurogenesis, resulting in neural tube thickening at early stages. Expression of the Plxdc2 extracellular domain alone, which can be cleaved and shed in vivo, is sufficient for this activity, demonstrating a cell non-autonomous function. Induction of proliferation is also observed in cultured embryonic neuroepithelial cells (ENCs) derived from E9.5 mouse neural tube, which express a Plxdc2-binding activity. These experiments uncover a direct molecular activity of Plxdc2 in the control of proliferation, of relevance in understanding the role of this protein in various cancers, where its expression has been shown to be altered. They also implicate Plxdc2 as a novel component of the network of signalling molecules known to coordinate proliferation and differentiation in the developing nervous system

Recovery of dialysis patients with COVID-19 : health outcomes 3 months after diagnosis in ERACODA

Background. Coronavirus disease 2019 (COVID-19)-related short-term mortality is high in dialysis patients, but longer-term outcomes are largely unknown. We therefore assessed patient recovery in a large cohort of dialysis patients 3 months after their COVID-19 diagnosis. Methods. We analyzed data on dialysis patients diagnosed with COVID-19 from 1 February 2020 to 31 March 2021 from the European Renal Association COVID-19 Database (ERACODA). The outcomes studied were patient survival, residence and functional and mental health status (estimated by their treating physician) 3 months after COVID-19 diagnosis. Complete follow-up data were available for 854 surviving patients. Patient characteristics associated with recovery were analyzed using logistic regression. Results. In 2449 hemodialysis patients (mean ± SD age 67.5 ± 14.4 years, 62% male), survival probabilities at 3 months after COVID-19 diagnosis were 90% for nonhospitalized patients (n = 1087), 73% for patients admitted to the hospital but not to an intensive care unit (ICU) (n = 1165) and 40% for those admitted to an ICU (n = 197). Patient survival hardly decreased between 28 days and 3 months after COVID-19 diagnosis. At 3 months, 87% functioned at their pre-existent functional and 94% at their pre-existent mental level. Only few of the surviving patients were still admitted to the hospital (0.8-6.3%) or a nursing home (∼5%). A higher age and frailty score at presentation and ICU admission were associated with worse functional outcome. Conclusions. Mortality between 28 days and 3 months after COVID-19 diagnosis was low and the majority of patients who survived COVID-19 recovered to their pre-existent functional and mental health level at 3 months after diagnosis

Adsorption of Benzene & Cumene on NaX Zeolite & Its Scandium Forms at Low & High Temperatures

1016-101

Studies on the NaX Zeolite & Its Scandium Substituted Forms

33-3