Nowadays, international exchanges are becoming more and more frequent in the world. As a global language, English can establish a communication bridge between different countries and nationalities, and its importance is obvious. Since 2001, China has gradually added English education to the curriculum plan of primary schools in various regions. Later, with the deepening of the industry’s understanding of English teaching, the education reform has also followed up. It can be said that the level of educators and educates is rising spirally. However, there are still many restrictive factors in the current situation of primary school students’ learning English, among which the more prominent factors are the strength of English teachers and the evaluation mechanism for students’ learning achievements.
It is well known that determining the exact values of crossing number for circulant graphs is very difficult. Even so, some important results in this field are still proved. D.J. Ma was proved that the crossing number of C(2m + 2, m) is m + 1[8]. Then such problem for C(n, 3) was further solved [7]. Pak Tung Ho and X. Lin obtained accurate values for the crossover numbers of C (3m, m) and C (3m + 1, m)[4][5]. In this paper, as a complement, we show that the edges from the principal cycle of C(9, 3) do not cross each other in an optimal drawing.
Although dykes are a predominant and widely distributed phenomenon in S-Algeria, N-Mali and N-Niger, a systematic, standardized inventory of dykes covering these areas has not been published so far. Remote sensing and geo information system (GIS) tools offer an opportunity for such an inventory. This inventory is not only of interest for the mining industry as many dykes are related to mineral occurrence of economic value, but also for hydrogeologic investigations (dykes can form barriers for groundwater flow). Surface-near dykes, major fault zones, volcanic and structural features were digitized based on Landsat 8 and 9, Sentinel 2, Sentinel 1 and ALOS PALSAR data. High resolution images of World Imagery files/ESRI and Bing Maps Aerial/Microsoft were included into the evaluations. More than 14,000 dykes were digitized and analyzed. The evaluations of satellite images allow a geomorphologic differentiation of types of dykes and the description of their characteristics such as dyke swarms or ring dykes. Dykes are tracing zones of weakness like faults and zones with higher geomechanically strain. Dyke density calculations were carried out in ArcGIS to support the detection of dyke concentrations as stress indicator. Thus, when occurring concentrated, they might indicate stressed areas where further magmatic and earthquake activity might potentially happen in future.
According to the World Health Organization (WHO), breast cancer is among the most common cancers worldwide. Most of the anticancer agents have been showing a variety of side effects. Recently, bacterial proteins have been investigated as promising anticancer agents. Azurin is a bacterial cupredoxin protein secreted from Pseudomonas aeruginosa and has been reported as a potent multi-targeting anticancer agent, which makes it an appropriate candidate for drug delivery. Azurin may be delivered to cancer cells using different carriers like polymeric micro and nanoparticles. In the present study, azurin was extracted from the bacterial host and loaded into chitosan particles. Then its effect on MCF-7 cell line was investigated. Chitosan-azurin particles were made using the ion gelation method. Results showed that chitosan-azurin particles are about 200 nm, and the loading of the protein in particles did not affect its integrity. The MTT assay showed a significant reduction in cell viability in azurin and chitosan-azurin-treated cells. The toxicity level after 5 days was 63.78% and 82.53% for free azurin and chitosan-azurin-treated cells, respectively. It seems using an appropriate carrier system for anticancer proteins like azurin is a promising tool for developing low side effect anticancer agents.
In this paper, we deal with one of the most urgent and relevant topics nowadays, i.e., water pollution. The problem is finding a valid candidate for the absorption and removal of different kinds of pollutants commonly found in water. There are already some indications about graphene oxide as a potential candidate. In the present work, we take a step forward to show how graphene nanoplatelets (rather than the oxide form of this material) are capable of decontaminating water. In this starting step, we use a specific substance as a model pollutant, i.e., acetonitrile, leaving for the future steps, to extend the analysis to additional types of pollutants. In addition to laboratory-produced graphene nanoplatelets, we already examined in the past; now we wish to consider also commercially available ones, so that the new results will not be bound to a laboratory (low technology readiness level) material, but will become interesting also from the industrial point of view, thanks to the scalability of the nanoplatelets production. For this aim, we compare the performance of two types of filters based on two classes of nanomaterials, i.e., those produced by microwave and ultrasound assisted exfoliation, already analyzed in our earlier works, with those commercially distributed by an Italian company, i.e., NANESA, http://www.nanesa.com/. The latter is an innovative SME involved in the production of graphene-based nanomaterials. We focus here in the graphene nanoplatelets, commercially available in industrial batches (GXNan grades). The present study leads to determine which filtering membrane, among the various types of commercial graphene considered, shows the greatest stability, and the lack of breakage of the membrane, concentrating on such accessory features, given that all types of graphene showed excellent adsorption properties.
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