Effect of size and processing method on the cytotoxicity of realgar nanoparticles in cancer cell lines

In this study, the effects of the size and Chinese traditional processing (including elutriation, water cleaning, acid cleaning, alkali cleaning) on realgar nanoparticles (RN)-induced antitumor activity in human osteosarcoma cell lines (MG-63) and hepatoma carcinoma cell lines (HepG-2) were investigated. The human normal liver cell line (L-02) was used as control. RN was prepared by high-energy ball milling technology. The results showed that with the assistance of sodium dodecyl sulfate, the size of realgar could be reduced to 127 nm after 12 hours’ ball milling. The surface charge was decreased from 0.83 eV to −17.85 eV and the content of As2O3 clearly increased. Except for elutriation, the processing methods did not clearly change the size of the RN, but the content of As2O3 was reduced dramatically. In vitro MTT tests indicated that in the two cancer cell lines, RN cytotoxicity was more intense than that of the coarse realgar nanoparticles, and cytotoxicity was typically time- and concentration-dependent. Also, RN cytotoxicities in the HepG-2 and L-02 cells all increased with increasing milling time. Due to the reduction of the As2O3 content, water cleaning, acid cleaning, and alkali cleaning decreased RN cytotoxicity in HepG-2, but RN after elutriation, with the lowest As2O3 (3.5 mg/g) and the smallest size (109.3 nm), showed comparable cytotoxicity in HepG-2 to RN without treatment. Meanwhile, RN-induced cytotoxicity in L-02 cells was clearly reduced. Therefore, it can be concluded that RN may provide a strong antiproliferation effect in the MG-63 and HepG-2 cells. Elutriation processing is a suitable approach to limit the dangerous side-effects of As2O3, while maintaining the effectiveness of RN

Gradient Method for Continuous Influence Maximization with Budget-Saving Considerations

Continuous influence maximization (CIM) generalizes the original influence maximization by incorporating general marketing strategies: a marketing strategy mix is a vector $\boldsymbol x = (x_1,\dots,x_d)$ such that for each node $v$ in a social network, $v$ could be activated as a seed of diffusion with probability $h_v(\boldsymbol x)$, where $h_v$ is a strategy activation function satisfying DR-submodularity. CIM is the task of selecting a strategy mix $\boldsymbol x$ with constraint $\sum_i x_i \le k$ where $k$ is a budget constraint, such that the total number of activated nodes after the diffusion process, called influence spread and denoted as $g(\boldsymbol x)$, is maximized. In this paper, we extend CIM to consider budget saving, that is, each strategy mix $\boldsymbol x$ has a cost $c(\boldsymbol x)$ where $c$ is a convex cost function, we want to maximize the balanced sum $g(\boldsymbol x) + \lambda(k - c(\boldsymbol x))$ where $\lambda$ is a balance parameter, subject to the constraint of $c(\boldsymbol x) \le k$. We denote this problem as CIM-BS. The objective function of CIM-BS is neither monotone, nor DR-submodular or concave, and thus neither the greedy algorithm nor the standard result on gradient method could be directly applied. Our key innovation is the combination of the gradient method with reverse influence sampling to design algorithms that solve CIM-BS: For the general case, we give an algorithm that achieves $\left(\frac{1}{2}-\varepsilon\right)$-approximation, and for the case of independent strategy activations, we present an algorithm that achieves $\left(1-\frac{1}{e}-\varepsilon\right)$ approximation.Comment: To appear in AAAI-20, 43 page

Optical fibre high temperature sensors and their applications

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Stability analysis of gas solids separation in scaling-up fluidized bed reactors

In large industrial fluidized bed reactors with high gas solids flow rates, small cyclones working in parallel are often preferred to achieve higher efficiency in the case of uniform distribution of gas-solid two-phase flow across each inlet. However, there is mounting evidence1-5 that gas-solid suspensions pass through identical paths in parallel can be significantly non-uniform, resulting in a dramatically drop in overall efficiency. In this study we used the direct Liapunov method by considering the interaction between gas and solids to detect the instability of uniformity. Owing to the special symmetry in this system, the criterion can be simplified into identifying the concavity (concave or convex) of pressure drop across a single cyclone with respect to operational parameter CT. Then, based on the stability analysis of uniformity, a novel design principle is provided to prevent non-uniform distribution at high dust loading. The effect of geometrical factor, i.e. dimensionless vortex finder diameter dr, on the stability of uniformity has been further investigated. The phase diagram of stability is calculated to give a clue of designing robust parallel cyclones system. Please click Additional Files below to see the full abstract

Evaluation of TGF-β1 and MCP-1 expression and tubulointerstitial fibrosis in children with Henoch-Schönlein purpura nephritis and IgA nephropathy: A clinical correlation

OBJECTIVES: Henoch-Schönlein purpura nephritis and immunoglobulin A nephropathy are two diseases with similar clinical presentations but very different prognoses. Transforming growth factor β1 and monocyte chemoattractant protein-1 have been associated with the development of tissue fibrosis. We examined the development of tubulointerstitial fibrosis and its relationship with Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in these patients. METHODS: Renal tissue samples were collected by renal biopsy from 50 children with Henoch-Schönlein purpura nephritis and 50 children with immunoglobulin A nephropathy. Hematoxylin and eosin and Masson's trichrome-stained tissues were examined using light microscopy. Tubulointerstitial fibrosis was graded using the method described by Bohle et al. (1). The immunohistochemical detection of Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was correlated with the tubulointerstitial fibrosis grade. Clinical Trial registration number: ZJCH-2012-0105. RESULTS: Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in the renal tissues was significantly greater in the patients with immunoglobulin A nephropathy than in the patients with Henoch-Schönlein purpura nephritis (both

Refractive errors in 3-6 year-old Chinese children: a very low prevalence of myopia?

PURPOSE To examine the prevalence of refractive errors in children aged 3-6 years in China. METHODS Children were recruited for a trial of a home-based amblyopia screening kit in Guangzhou preschools, during which cycloplegic refractions were measured in both eyes of 2480 children. Cycloplegic refraction (from 3 to 4 drops of 1% cyclopentolate to ensure abolition of the light reflex) was measured by both autorefraction and retinoscopy. Refractive errors were defined as followed: myopia (at least -0.50 D in the worse eye), hyperopia (at least +2.00 D in the worse eye) and astigmatism (at least 1.50 D in the worse eye). Different definitions, as specified in the text, were also used to facilitate comparison with other studies. RESULTS The mean spherical equivalent refractive error was at least +1.22 D for all ages and both genders. The prevalence of myopia for any definition at any age was at most 2.5%, and lower in most cases. In contrast, the prevalence of hyperopia was generally over 20%, and declined slightly with age. The prevalence of astigmatism was between 6% and 11%. There was very little change in refractive error with age over this age range. CONCLUSIONS Previous reports of less hyperopic mean spherical equivalent refractive error, and more myopia and less hyperopia in children of this age may be due to problems with achieving adequate cycloplegia in children with dark irises. Using up to 4 drops of 1% cyclopentolate may be necessary to accurately measure refractive error in paediatric studies of such children. Our results suggest that children from all ethnic groups may follow a similar pattern of early refractive development, with little myopia and a hyperopic mean spherical equivalent over +1.00 D up to the age of 5-6 years in most conditions.Supported by the National Natural Science Foundation of China, Beijing, China (grant no.: 81200714;http://www.nsfc.gov.cn/); Foundation for Distinguished Young Talents in Higher Education of Guangdong, Guangdong Province, China (grant no.: LYM 11009;http://www.gdhed.edu.cn/) and the Science and Information Technology Bureau of Guangzhou, Guangdong Province, China (grant no.: 2011Y2-00018-3;http://www.gzsi.gov.cn/)

Key technologies of microbial mining residual coal and CO2-fly ash co-filling in the impacted geological body of coal mining

The gob of coal mine is an important area for achieving the goal of “dual carbon” in China. The geological body formed by coal mining, which can enrich coalbed methane and provide substrate and space for later microbial activities and mineralization filling is defined as the mining influence body. The proposed technologies include the residual coal extraction through mining influence body microorganisms and the co-mineralization and filling of CO2-fly ash. The broad prospects of the technology in the secondary development of mining, from the perspectives of necessity and feasibility, are elaborated upon regarding the safe storage of CO2 and efficient disposal of fly ash solid waste in coal-fired power plants. The overall concept is to utilize mining influence body as a anaerobic fermentation “factory” and microorganisms as “workers” to process the existing raw materials of the “factories”including residual coal, thin coal seams, dispersed organic matter, and injected CO2. The ultimate goal is to produce methane, thereby achieving the resource utilization of microbial mining for residual coal and CO2. The combination of CO2 and alkaline fly ash simultaneously achieves the mineralization storage of CO2 and the filling of mining influence body. The key scientific issues are involved in this technology encompass the classification of mining influence body and the characteristics of organic matter, elucidating the mechanism of anaerobic fermentation under in-situ conditions specific to mining influence body, investigating the cooperative mineralization mechanism of microbial-CO2-fly ash, as well as undertaking a demonstration project for constructing the key technology of microbial residual coal mining and filling. The laboratory physical simulation of the in-situ conditions of the mining influence body demonstrates that the residual coal and organic-rich mud shale have the capability to generate biomethane, with methane production further enhanced by a small quantity of fly ash. The dynamic experiment of simulated groundwater recharge demonstrates that the nutrient recharge significantly impacts the anaerobic fermentation system. Specifically, the system with a cycle period of 14 days was consistent with the cycle of methanogens, which can ensure the continuous and efficient operation of the anaerobic fermentation system. After a curing period of 28 days, the test specimen containing high calcium fly ash, CO2, and mine water exhibited a compressive strength of 12.31 MPa. Additionally, each ton of fly ash had the potential to store approximately 21.99 m3 of CO2 through mineralization, highlighting the dual benefits of CO2 emission reduction and goaf solidification achieved by utilizing fly ash. The engineering test target area was optimized based on the purpose of microbial coal residue mining and fly ash filling. Also, the groundwater retention area was identified as the optimal location for CO2 mineralization and fly ash filling. The natural trap formed by mining activities and the trap formed by artificial filling were one of the more favorable engineering test targets. The proposed technologies of microbial residual coal mining, CO2 and fly ash co-filling are aimed at providing a novel technical approach for carbon emission reduction and goaf ecological environment management in China

Computational Analysis of Drought Stress-Associated miRNAs and miRNA Co-Regulation Network in Physcomitrella patens.

miRNAs are non-coding small RNAs that involve diverse biological processes. Until now, little is known about their roles in plant drought resistance. Physcomitrella patens is highly tolerant to drought; however, it is not clear about the basic biology of the traits that contribute P. patens this important character. In this work, we discovered 16 drought stress-associated miRNA (DsAmR) families in P. patens through computational analysis. Due to the possible discrepancy of expression periods and tissue distributions between potential DsAmRs and their targeting genes, and the existence of false positive results in computational identification, the prediction results should be examined with further experimental validation. We also constructed an miRNA co-regulation network, and identified two network hubs, miR902a-5p and miR414, which may play important roles in regulating drought-resistance traits. We distributed our results through an online database named ppt-miRBase, which can be accessed at http://bioinfor.cnu.edu.cn/ppt_miRBase/index.php. Our methods in finding DsAmR and miRNA co-regulation network showed a new direction for identifying miRNA functions

Enhancement of bioconversion of coal to methane by graphene

The research of enhancing biomethanation of coal has been paid much attention, which is an effective measure for increasing coalbed methane production. Adding conductive material to the digestive system can effectively accelerate direct interspecific electron transfer and increase methane production, which has great potential in enhancing the anaerobic digestion of organic matter. In this study, long-flame coal was used as the substrate to construct an anaerobic digestion system. The effect of the addition of graphene on biomethane production was discussed from the aspects of cumulative methane yield, the changes of key intermediates in the liquid phase, the microbial community structure, the methane metabolic pathway, and the changes of surface functional groups in residual coal after anaerobic digestion. The results showed that adding 0.4 g/L of graphene to the anaerobic digestion system based on coal effectively enhanced the entire anaerobic digestion process, not only enhanced methane production, but also brought forward the peak of methane production. At the early stage of digestion, the activities of hydrolytic bacteria (Paraclostridium) and hydrogen-production and aceogenic microflora (Alcaligenes and Sphaerochaeta) were enhanced, and sufficient nutrients were accumulated in the early stage. At the peak of methane production, the abundance of Methanoculleus decreased while the abundance of Methanosarcina significantly increased after the addition of graphene. The β subunit and γδ subunit of acetyl-coa decarbonyase/synthase, as key enzymes in the acetic acid synthesis pathway, increased by 233.54% and 3.32%, respectively. This significantly increased the abundance of Methanosarcina and mainly produced methane in the form of acetic acid nutrition. The abundance of Geobacter and Anaerovorax bacteria that can use ethyl acetate increased, and the Geobacter with high abundance were likely to DIET with Methanosarcina by bioelectric connection assisted by graphene. This electron transport mode accelerated the formation of biomethane to some extent. The carbonyl carbon (C=O) and carboxyl carbon (COO—) on the surface of residual coal decreased by 42.8% and 49.5%, respectively, after the addition of graphene, indicating that graphene effectively promoted the degradation of coal by microflora. The addition of graphene improves the activity and degradation efficiency of microflora, speeds up the process of anaerobic digestion, provides abundant substrate for methanogenic microflora, and improves methane production