Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro

BACKGROUND: Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. METHODS: The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. RESULTS: The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. CONCLUSIONS: Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma

An eco-city indicator system for the city of Changsha.

With rapid urban development in China, many cities are still concerned about the quantity of the economy growth while ignoring the quality of the growth; ecological systems face a challenging situation. How to evaluate and guide a sustainable devel-opment is a vitally important question to the government of China. The study was partly performed in cooperation with the Institute of Building Research (IBR), who was entrusted by Changsha government of the Hunan Province. To evaluate the sus-tainability of urban development, a comprehensive indicator system was developed and applied, which was consistent to the policy of the so called "Two oriented socie-ty", which means Resource conservation and Environment friendly society. This pa-per shows a logic methodology to develop an indicator system – through the re-search, from literature review to modern concept; it shows clearly the factors that are important to build a sustainable city. The indicator system was derived and compared with other existing systems. The comparison showed that the indicator system we developed for the city is operational and integrated with a consistent hierarchy. Thereafter, the established indicator sys-tem was evaluated using an Analytical Hierarchy Process methodology. Indictors of ecological aspects were evaluated using the data collected, including the Changsha green field map, wetland map and ecological control maps. The indicator system was applied and the result was used as decision support in urban planning for 2020. How-ever, a main limitation lied in data collection: since the data we collected was not completely the data we expected. Besides, the indicator system was developed on the base of the policy called the "Two oriented society",which has its preference and limi-tation itself. Still, in sum, the indicator system we built through the research provided a satisfactory framework to the government to guide the development of the society in a macro scale. It needs future involvement to improve the data collection and standardization

A realistic appraisal of boron neutron capture therapy as a cancer treatment modality

Abstract Boron neutron capture therapy (BNCT) is a binary therapeutic modality based on the nuclear capture and fission reactions that occur when the stable isotope boron-10 is irradiated with neutrons to produce high-energy alpha particles and recoiling lithium-7 nuclei. In this Commentary we will focus on a number of papers that were presented at a Symposium entitled “Current Clinical Status of Boron Neutron Capture Therapy and Paths to the Future”, which was held in September 2017 at the China National Convention Center in Beijing. Results were presented by clinicians from Japan, Finland, the United States, the China mainland and Taiwan, China who have been working in the multiple disciplines that are required for carrying out clinical BNCT. The main focus was on the treatment of patients with malignant brain tumors, recurrent tumors of the head and neck region, and cutaneous melanomas. The results obtained in treating these patients were reported in detail and, although most of the patients with brain tumors and head and neck cancer were not cured, there was evidence of some clinical efficacy. Although there are a number of problems that must be addressed, further clinical studies to evaluate the efficacy of BNCT are warranted. First, despite considerable effort by numerous investigators over the past 40 years, there still are only two boron-containing drugs in clinical use, l-boronophenylalanine (BPA) and sodium borocaptate (BSH). Therefore, until new and more effective boron delivery agents are developed, efforts should be directed to improving the dosing and delivery of BPA and BSH. Second, due to a variety of reasons, nuclear reactor-based BNCT has ended except for its use in the China mainland and Taiwan. Therefore, the future of BNCT depends upon the results of the ongoing Phase II clinical trials that are being carried out in Japan and the soon to be initiated trials that will be carried out in Finland. If the results obtained from these clinical trials are sufficiently promising, then BNCT will have a clear path to the future, especially for patients with the therapeutically challenging malignancies that in the past have been treated with reactor-based BNCT

A Study on the retweeting behaviour of marketing microblogs with high retweets in Sina Weibo

This research studies marketing microblogs with high retweets in Sina Weibo. The content features of marketing microblogs, the structural and temporal characteristics of retweet networks, the major features of retweeters, the incentive mechanisms for retweeting, and the influential retweeters are investigated. A microblog dataset including 19,889 microblogs from 20 enterprise accounts and a retweet network dataset including 207,649 retweets and 113,755 retweeters are analysed. This analysis shows that the marketing microblogs with high retweets are normally the results of some incentive mechanisms, high percentage of their retweets are retweeted from the original microblog directly, the frequencies of retweets vary over the activity periods, incentive mechanisms can significantly affect the behaviour of retweeters, and influential retweeters have significant impact on arousing subsequent retweets. These results could be utilized by enterprises for improving their marketing activities.8 page(s

A Hybrid feature selection method for predicting user influence on Twitter

This paper proposes a hybrid feature selection method for predicting user influence on Twitter. A set of candidate features from Twitter is identified based on the five attributes of influencers defined in sociology. Firstly, less relevant features are filtered out with a featureweighting algorithm. Then the Sequential Backward Floating Selection is utilized as the search strategy. A Back Propagation Neural Network is employed to evaluate the feature subset at each step of searching. Finally, an optimal feature set is obtained for predicting user influence with a high degree of accuracy. Experimental results are provided based on a real world Twitter dataset including seven million tweets associated with 200 popular users. The proposed method can provide a set of features that could be used as a solid foundation for studying complicated user influence evaluation and prediction.15 page(s

An Effective Lunar Crater Recognition Algorithm Based on Convolutional Neural Network

The lunar crater recognition plays a key role in lunar exploration. Traditional crater recognition methods are mainly based on the human observation that is usually combined with classical machine learning methods. These methods have some drawbacks, such as lacking the objective criterion. Moreover, they can hardly achieve desirable recognition results in small or overlapping craters. To address these problems, we propose a new convolutional neural network termed effective residual U-Net (ERU-Net) to recognize craters from lunar digital elevation model (DEM) images. ERU-Net first detects crater edges in lunar DEM data. Then, it uses template matching to compute the position and size of craters. ERU-Net is based on U-Net and uses the residual convolution block instead of the traditional convolution, which combines the advantages of U-Net and residual network. In ERU-Net, the size of the input image is the same as that of the output image. Since our network uses residual units, the training process of ERU-Net is simple, and the proposed model can be easily optimized. ERU-Net gets better recognition results when its network structure is deepened. The method targets at the rim of the crater, and it can recognize overlap craters. In theory, our proposed network can recognize all kinds of impact craters. In the lunar crater recognition, our model achieves high recall (83.59%) and precision (84.80%) on DEM. The recall of our method is higher than those of other deep learning methods. The experiment results show that it is feasible to exploit our network to recognize craters from the lunar DEM

Synthesis of Alumina-Supported RhSn Alloy Nanocatalysts by Using Rh@Sn Core–Shell Nanoparticle Precursors for Toluene Catalytic Hydrogenation

In this work, alumina-supported RhSn alloy nanocatalysts were prepared for toluene hydrogenation. Rh@Sn core–shell nanoparticles were first synthesized through a sequential reduction method and then in situ transformed into RhSn alloy on alumina by calcination and H2 reduction. Relative to Rh/Al2O3, Rh1Sn0.7/Al2O3 catalysts demonstrate enhanced catalytic efficiency for hydrogenation of toluene. At a toluene/Rh molar ratio of 118/1, 0.1 MPa of H2 pressure, and 45 °C, 99.2% of methyl cyclohexane yield was achieved at 2.0 h. The enhanced catalytic efficiency of Rh1Sn0.7/Al2O3 can be ascribed to the synergistic effect between Rh and Sn

Simultaneous implementation of resistive switching and rectifying effects in a metal-organic framework with switched hydrogen bond pathway

Resistive random-access memory (RRAM) has evolved as one of the most promising candidates for the next-generation memory, but bistability for information storage, simultaneous implementation of resistive switching and rectification effects, and a better understanding of switching mechanism are still challenging in this field. Herein, we report a RRAM device based on a chiral metal-organic framework (MOF) FJU-23-H2O with switched hydrogen bond pathway within its channels, exhibiting an ultralow set voltage (~0.2 V), a high ON/OFF ratio (~105), and a high rectification ratio (~105). It is not only the first MOF with voltage-gated proton conduction but also the first single material showing both rectifying and resistive switching effects. By single-crystal x-ray diffraction analyses, the mechanism of the resistive switching has been demonstrated.Published versio