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The evaluation of flotation reagents performs an important role in the selection and green application of reagents. The green indexes and effect indexes of flotation collectors were selected by data literature method, system analysis method, mathematical model method, and qualitative and quantitative analysis method, and the green evaluation system of flotation collectors, flotation effect evaluation system, and comprehensive evaluation system of flotation collectors were established. The normalization method and expert evaluation methods were adopted to obtain the grade classification of quantitative and qualitative indicators, respectively. The analytic hierarchy process (AHP) was used to determine the weight of secondary indicators and tertiary indicators of the evaluation system and the weight of indicators at a lower level. Applying the fuzzy comprehensive evaluation (FCE), the trapezoidal function is selected to determine the index affiliation, the index system score is calculated according to the weighted average principle, and finally, the established evaluation system is applied in an example. The example application shows that the comprehensive evaluation system of flotation collectors can make a comprehensive evaluation of collectors from the aspects of the greenness of reagent, flotation effect, and cost, and it has a strong target and practicality for collectors evaluation. The establishment of the system has a guiding significance for the selection and use of flotation collectors.

Background Early diagnosis improves the prognosis for non‐small cell lung cancer (NSCLC); therefore, there is a pressing need for effective diagnostic methods for NSCLC. Increasing evidence indicates that serum exosomal micro RNAs (miRNAs) represent promising diagnostic and prognostic markers for multiple cancers. Here, we explored a panel of miRNAs for NSCLC diagnosis and functionally characterized miR‐1269a in the pathogenesis of NSCLC. Methods: First, we analyzed high‐throughput data from The Cancer Genome Atlas (TCGA) to identify differentially expressed miRNAs between NSCLC patients and healthy controls. We examined the expression profiles of the identified miRNAs using qRT‐PCR. Results: We found that four micro‐RNAs (hsa‐miR‐9‐3p, hsa‐miR‐205‐5p, hsa‐miR‐210‐5p, and hsa‐miR‐1269a) were more abundant in serum exosomes from NSCLC patients. A logistic regression model validated the diagnostic efficacy of the four‐microRNA panel, allowing us to distinguish NSCLC patients from healthy controls with AUCs of 0.915 and 0.878 for the training and validation sets, respectively. Functionally, NSCLC cell proliferation, migration, and invasion were affected by the aberrant expression of hsa‐miR‐1269a in culture. Reduced expression of miR‐1269a resulted in reduced proliferation, migration, and invasion through targeting the forkhead box O1 gene (FOXO1). Conclusions: Taken together, our study identified a panel of four serum exosomal miRNAs as a potential noninvasive diagnostic biomarker for NSCLC. The interactions between FOXO1 and miR‐1269a represent novel potential targets for NSCLC therapy., Four serum exosomal miRNA panel as a potential non‐invasive diagnostic biomarker for NSCLC. The interactions of FOXO1 and miR‐1269a may represent novel potential targets for NSCLC therapy.

In terms of the important research topics of COVID-19 epidemic, and the development of modern education thoughts, learning community concept has gradually been developed into a perfect educational theory, which attaches great attention to social culture, authentic learning environment, cooperative construction of knowledge meaning and the rebuilding of social identity. In a network environment, advantages of online learning community become obvious in satisfying online teaching necessity and the growing diversified needs of the society. This study focuses on the construction of online learning community of Advanced English Course, which is a new approach of practicing the distant learning thoughts and further boosting online education. It starts with the definition of learning community, then the process of constructing online learning community, and difficulties, advantages, disadvantages and count-measures are put forward in considering the effectiveness of construction. This study also provides some enlightenment for the practical exploration on improving student's autonomous learning ability through online learning community, so as to offer reference for implementing online student learning community effectively.

At least three months have been passed since the outbreak of the severe acute respiratory disease, COVID-19 in Wuhan city, China in December 2019, caused by the infection of a novel coronavirus, SARS-CoV-2.1,2. Due to its rapid spread throughout China and abroad, knowledge sharing for both its epidemiology and clinic manifestations is urgently need. Here we analyzed the clinical, molecular and immunological data from 326 confirmed cases of SARS-CoV-2 infection in Shanghai. Genomic sequences assembled from 112 quality samples together with uploaded sequences in Global Initiative on Sharing All Influenza Data (GISAID) showed a stable evolution and suggested two major lineages with differential exposure history during the earliest outbreak in Wuhan. Nevertheless, they exhibited similar virulence and clinical outcomes. Lymphocytopenia, especially the reduced CD4+ and CD8+ T cell counts upon admission, was predictive of disease progression. High level of IL-6 and IL-8 during treatment was observed in severe and critical patients and correlated with decreased lymphocyte count. The determinants of disease severity seemed to stem mostly from host factors such age, lymphocytopenia and its associated cytokine storm whereas viral genetic variation did not significantly affect the outcomes. This comprehensive analysis on the molecular, immunological and clinical data provides a panorama of the key determinants related to the disease outcomes which should be helpful for improving the current combat against this extremely aggressive pandemic.Authors Xiaonan Zhang, Yun Tan, Yun Ling, Gang Lu, Feng Liu, and Zhigang Yi contributed equally to this work.

As a powerful nondestructive inspection technique, X-ray computed tomography (X-CT) has been widely applied to clinical diagnosis, industrial production and cutting-edge research. Imaging efficiency is currently one of the major obstacles for the applications of X-CT. In this paper, a multi-mounted three dimensional cone-beam X-CT (MM-CBCT) method is reported. It consists of a novel multi-mounted cone-beam scanning geometry and the corresponding three dimensional statistical iterative reconstruction algorithm. The scanning geometry is the most iconic design and significantly different from the current CBCT systems. Permitting the cone-beam scanning of multiple objects simultaneously, the proposed approach has the potential to achieve an imaging efficiency orders of magnitude greater than the conventional methods. Although multiple objects can be also bundled together and scanned simultaneously by the conventional CBCT methods, it will lead to the increased penetration thickness and signal crosstalk. In contrast, MM-CBCT avoids substantially these problems. This work comprises a numerical study of the method and its experimental verification using a dataset measured with a developed MM-CBCT prototype system. This technique will provide a possible solution for the CT inspection in a large scale.

Coal with its complex porous medium and abundant oxygen functional groups could be used as an adsorbent to adsorb organic compounds. Adsorption experiments and molecular dynamics simulations were carried out to study the behavior of methylene blue (MB) on the surface of Wiser bituminous coal. The influence of adsorption through factors, such as pulverized coal dosage, adsorption reaction time, initial concentration, and temperature effect, was investigated. The removal efficiency of MB reached 96.5% under optimum reactive conditions. The adsorption equilibrium was accorded with a Langmuir isotherm adsorption equation. The adsorption of MB onto coal was a spontaneous process because the adsorption free energy ΔG0 was negative. It was consistent with the conclusion of a negative interaction energy between bituminous coal and MB obtained by molecular dynamics simulation. Moreover, the density distribution along z-axis of each component molecule showed that MB molecules were adsorbed on the coal surface because of the polar interactions between the methyl groups of MB and the hydrophilic sites at the coal surface. Also, the diffusion degree of water molecule in liquid phase showed that as MB molecules formed hydrogen bonds with the water molecules, the activity of water molecules was restricted.

Massive Open Online Courses (MOOCs) have been rapidly increasing globally. In recent years, MOOCs and flipped classroom have drawn great attention from educators around the world. In China, these new learning models are being practiced by more and more college English teachers and students in their teaching and learning. To better understand the impact of MOOCs on current and future e-education globally, this paper reports an empirical study of Yunnan Open University (YNOU). In this study there are totally 32 teachers and 145 students answered the questionnaires, meanwhile 10 teachers randomly chosen were asked to take part in the in-depth interviews which were recorded and analyzed. The survey results demonstrate that there are some strengths and some limitations as well in using MOOCs. Five suggestions have been put forward for college English teachers and faculty members. Taking the impact of MOOCs on college English education into consideration, three stages are initiated for the construction of efficient integration of MOOCs and college English education. Furthermore, opportunities and challenges of MOOCs for traditional classroom practices and adult program management are discussed.

Although clean coal utilization has attracted much attention, it is challenging to treat coal chemical wastewater. In this work, the coking wastewater was treated by bituminous coal adsorption and composite advanced oxidation technology. The effect of adsorption on organic separation and the synergy between UV and electrochemistry were investigated. The results indicated that the removal of total organic carbon (TOC), chroma, and UV254 by bituminous coal adsorption was effective. And polycyclic aromatic hydrocarbons were preferentially adsorbed, followed by phenols and aliphatic hydrocarbons. After bituminous coal adsorption and electrochemical/UV/H2O2 treatment, the TOC of coking wastewater decreased by 68.92%, which was better than adsorption/electrochemical and adsorption/UV. Through excitation-emission matrix (EEM) and gas chromatography-mass spectrometry (GC–MS) analysis, the improvement of biodegradability was attributed to the reduction of polycyclic aromatic hydrocarbons, long-chain alkane, and nitrogen heterocyclic compounds in the coking wastewater. UV photocatalysis and electrochemical had synergistic effects on the degradation of polycyclic aromatic hydrocarbons. Besides, the active chlorine could be regulated by adjusting the current density and the dosage of hydrogen peroxide.

X-ray phase-contrast imaging has attracted much more attention in researches, due to the better imaging contrast than absorption when the sample is made of light elements. However, X-ray phase retrieval procedure based on differential phase-contrast imaging (DPCI) is time-consuming because of the phase stepping technique, which is a necessary step of accurate retrieval of phase information. In this work, we proposed a single-shot method based on DPCI without phase stepping by designing a new absorption grating. It can successfully distinguish the characteristic of the sample with greatly reduced imaging time and radiation dose, which makes it more practical in medical and industrial applications. An experimental data is implemented to support our idea.

Carbon fiber composites have been wildly used in aerospace industry due to the excellent performance. However, the research on defect evolution law and the performance analysis have been limited by the lack of effective tools. Two kinds of computed tomography (CT) slice images of carbon fiber composites, x-ray attenuation contrast and phase contrast, were obtained with the diffraction enhancement imaging (DEI) device at Beijing Synchrotron Radiation Facility (BSRF). The structure details and the defects in the sample could be clearly distinguished from the image. Moreover, phase contrast CT provides higher contrast and can identify the defects difficult to be recognized in attenuation contrast CT. DEI provides a method for in-situ observation of the carbon fiber composites and would be a valuable tool for the development of carbon fiber composite material.

We report here the clinical, genetic and molecular characterization of four Han Chinese families with Leber's hereditary optic neuropathy (LHON). The penetrances of optic neuropathy in these Chinese pedigrees were 38%, 38%, 44% and 56%. This observation is in contrast with the previously identified 14 Chinese families with very low penetrance of LHON. The age-at-onset for visual impairment in matrilineal relatives in these Chinese families varied from 18 to 30 years. Furthermore, the ratios between affected male and female matrilineal relatives in these families were 3:0, 3:0, 3:1 and 2:3, respectively. Molecular analysis of mitochondrial genomes identified the known ND4 G11778A mutation and distinct sets of variants belonging to the Asian haplogroups M9a. Of these, the ND1 T3394C mutation caused the substitution of a highly conserved histidine for tyrosine (Y30H) at amino acid position 30. This mutation was associated with LHON in other families with low penetrance of optic neuropathy and other clinical abnormalities. The presence of both G11778A and T3394C mutations appears to contribute to higher penetrance of optic neuropathy in these four Chinese families than other Chinese families carrying only the G11778A mutation. Therefore, the mitochondrial haplogroup M9a specific variant T3394C may modulate the phenotypic manifestation of LHON-associated G11778A mutation in these Chinese pedigrees.

Most existing X-ray computed tomography (CT) techniques work in single-mounted mode and need to scan the inspected objects one by one. It is time-consuming and not acceptable for the inspection in a large scale. In this paper, we report a multi-mounted CT method and its first engineering implementation. It consists of a multi-mounted scanning geometry and the corresponding algebraic iterative reconstruction algorithm. This approach permits the CT rotation scanning of multiple objects simultaneously without the increase of penetration thickness and the signal crosstalk. Compared with the conventional single-mounted methods, it has the potential to improve the imaging efficiency and suppress the artifacts from the beam hardening and the scatter. This work comprises a numerical study of the method and its experimental verification using a dataset measured with a developed multi-mounted X-ray CT prototype system. We believe that this technique is of particular interest for pushing the engineering applications of X-ray CT.

The expression and functions of microRNA-361 (miR-361) have been studied in various human cancers. However, its expression and role in non‑small‑cell lung cancer (NSCLC) remains unclear. In the present study, the expression levels of miR‑361 in NSCLC tissues and cell lines were determined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). In addition, the effect of miR‑361 on the proliferation, migration and invasion of NSCLC cells was assessed. Furthermore, a dual‑Luciferase reporter assay, RT‑qPCR and western blotting were performed to investigate whether miR‑361 directly targeted the 3' untranslated region of Wilms' tumor 1 (WT1). The results of the present study revealed that miR‑361 was downregulated in NSCLC tissues and cell lines. Enforced expression of miR‑361 suppressed the proliferation, migration and invasion of NSCLC cells. WT1 was identified as a direct target gene of miR‑361 in NSCLC. Furthermore, knockdown of WT1 had similar effects to miR‑361 overexpression in NSCLC cells. The present study provided novel insights into the molecular mechanism underlying the rapid growth and metastasis of NSCLC, and identified the association between miR‑361 and WT1 as a potential therapeutic target for the treatment of NSCLC.

Self-assembled vesicles, structurally equivalent to some hydrotropes, have been obtained from a Zn2+-fluorous surfactant or in the mixture of Zn2+-fluorous surfactant/zwitterionic surfactant in room-temperature ionic liquids (RTILs). The existence of bilayers arranged in vesicles in RTILs would be very exciting, open several new possibilities as reaction media, and increase our understanding of the physical and chemical factors for self-assembling systems in RTILs.

Two routes to vesicle formation were designed to prepare uni- and multilamellar vesicles in salt-free aqueous solutions of surfactants. The formation of a surfactant complex between a double-chain anionic surfactant with a divalent-metal ion as the counterion and a single-chain zwitterionic surfactant with the polar group of amine-oxide group is described for the first time as a powerful driving force for vesicle-phases constructed from salt-free mixtures of aqueous surfactant solutions. As a typical example, a Zn(2+)-induced charged complex fluid, vesicle-phase has been studied in aqueous mixtures of tetradecyldimethylamine oxide (C(14)DMAO) and zinc 2,2-dihydroperfluorooctanoate [Zn(OOCCH(2)C(6)F(13))(2)]. This ionically charged vesicle-phase formed due to surfactant complexation has interesting rheological properties and is not shielded by excess salts because there are no counterions in the solution. Such a vesicle-phase of surfactant complex is important for many applications; for example, the vesicle-phase was further used to produce in situ the vesicle-phase of the salt-free cationic/anionic (catanionic) surfactants, C(14)DMAOH(+)-(-)OOCCH(2)C(6)F(13). The salt-free catanionic vesicle-phase could be produced through injecting H(2)S gas into the C(14)DMAO/Zn(OOCCH(2)C(6)F(13))(2) vesicle-phase, because the zwitterionic surfactant C(14)DMAO can be charged by the H(+) released from H(2)S to become a cationic surfactant and Zn(2+) was precipitated as ZnS. After the ZnS precipitates were removed from C(14)DMAO/Zn(OOCCH(2)C(6)F(13))(2) solutions, the final mixed solution does not contain excess salts as do other cationic/anionic surfactant systems. Both the C(14)DMAO-Zn(OOCCH(2)C(6)F(13))(2) complex and the resulting catanionic C(14)DMAOH(+)-(-)OOCCH(2)C(6)F(13) solution are birefringent Lalpha-phase solutions that consist of uni- and multilamellar vesicles. Ring-shaped semiconductor ZnS materials with encapsulated ZnS precipitates and regular spherical ZnS particles were prepared, which resulted in a transition from vesicles composed of metal-ligand complexes to vesicles held together by ionic interactions in the salt-free aqueous systems. This strategy should provide a new method to prepare inorganic materials. The present routes to form vesicles solve a problem: how to prepare nanomaterials using surfactant self-assembly, with structure controlled not by the growing material, but by the phase behavior of the surfactants.

Zn2+-induced vesicle formation has been studied for the first time in aqueous mixtures of tetradecyldimethylamine oxide (C14DMAO) and zinc 2,2-dihydroperfluorooctanoate [Zn(C6F13CH2COO)2]. The charged vesicle phase without any cosurfactants was prepared in the aqueous mixtures. The charged vesicle phase has interesting rheological properties. This ionically charged vesicle phase is not shielded by excess salts because of salt-free aqueous solutions. Such a vesicle phase is important for many applications where cosurfactant is not used. A cationic/anionic surfactant C14DMAOH+ -OOCCH2C6F13 system could be produced from C14DMAO/Zn(C6F13CH2COO)2 mixtures because the zwiterionic surfactant C14DMAO can be charged by the H+ released from H2S to a cationic surfactant and Zn2+ is precipitated. After ZnS particles are removed from the cationic/anionic surfactant solutions, the finally mixed sample does not contain excess salts as do other studied cationic/anionic surfactant systems. The sample is a birefringent Lα-...

Modern open and distance education is characterized by web-based instruction, web-based assessment and research. The significance and necessity on formative assessment have been well acknowledged in the educational field. This paper firstly introduces the formative assessment innovation project conducted by China Central Radio & Television University (CCRTVU). Based on the “web-based formative assessment for English II (1)”, a required course for the non-English majors following B. A. programmes at Yunnan Radio and TV University (YNTVU, now renamed Yunnan Open University), it will mainly discuss whether it is feasible and effective to put the formative assessment online from the following three aspects: a thorough data analysis of the pilot project results; the strengths of web-based formative assessment compared with the paper-based formative assessment and finally the constraints on implementing web-based formative assessment system in the remote areas like Yunnan province, China. In the study, semi-structured in-depth interviews were employed to collect the participants’ feedback. The study found that web-based formative assessment, when carefully designed, organized and managed, is a very useful way of stimulating and facilitating student learning, it will promote students’ learning autonomy, ensure students’ learning process and help students develop their overall language competence as well.

A new fluorescent reagent, 2-hydroxy-1-naphthaldehydene-8-aminoquinoline (HNAAQ), was synthesized. The fluorescent reaction of this reagent with chromium was studied. Based on this chelation, a highly sensitive spectrofluorimetric method was developed for determination of trace amounts of chromium in a water-ethanol (4 + 1, v/v) medium at pH=9.4. Under these conditions, the Cr-HNAAQ complex has excitation and emission maxima at 397 and 450 nm, respectively. The linear range of the method is from 0 to 25 μg l− 1 and detection limit is 77 ng l− 1 of chromium. Interference of other ions was studied. It is necessary to remove the interfering cations through cation exchange resin. The selectivity of the method can increase obviously. The procedure can be easily performed and affords good precision and accuracy. This method has been successfully applied to the determination of chromium in pig liver and pork muscle.