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Background Many solid tumors rely heavily on the regulation and organization of leader and follower cells during the collective invasion. However, leader cells’ specific biomarkers and mechanisms in colorectal cancer (CRC) collective invasion are unclear. This study aimed to identify the specific biomarkers of leader cells and reveals their molecular mechanisms during CRC collective invasion and metastasis. Methods The 3D photoconvertible CRC spheroid model in vitro was constructed to isolate leader cells and follower cells. The RNA-Seq, functional, and animal experiments revealed that GLUT1, PLOD2, and CCL5 in leader cells were required for CRC collective invasion. Results CCL5 up-regulated the expression of GLUT1 and PLOD2 through PI3K/Akt signaling in leader cells. Moreover, GLUT1 and CCL5 could be used as specific biomarkers for leader cells in CRC collective invasion, and their co-expression was associated with poor prognosis of CRC patients. Notably, blocking GLUT1 and CCL5-CCR5 effectively inhibited CRC collective invasion. Conclusions Our findings illustrate that CCL5 and GLUT1 may define leader cells and are required for CRC collective invasion as a potential key regulator of hypoxia-induced metabolic shifts and collagen deposition.

Background Metabolic reprogramming has been shown to be involved in cancer-induced PMN formation, but the underlying mechanisms have been insufficiently explored. Methods HAO1 expression in lung tissues and alveolar epithelial cells were deteted by qPCR and Western blotting. The effect of HAO1 on the lung metastasis of cancer was investigated by orthotropic metastasis assay. Lungs and cells oxalate levels were determined using an oxalate assay kit. The effect of oxalate on neutrophil extracellular trap formation was investigated by immunofluorescence. The effect of oxalate on proliferation of breast cancer cells was revealed by immunofluorescence by colony formation assay. Results HAO1 was up-regulated in the alveolar epithelial cells of mice bearing metastatic breast cancer cells at the pre-metastatic stage. Upregulation of HAO1 led to oxalate accumulation in lung tissues and alveolar epithelial cells. Pharmacologic inhibition of HAO1 could effectively suppress the lung oxalate accumulation induced by primary cancer. Lung oxalate accumulation induced NET formation by activating NADPH oxidase. Lung oxalate accumulation promoted the proliferation of metastatic cancer cells by activating the MAPK signaling pathway. Breast cancer cells induced HAO1 expression and oxalate accumulation in alveolar epithelial cells by activating TLR3-IRF3 signaling. Conclusion These findings underscore the role of HAO1-mediated oxalate metabolism in cancer-induced lung PMN formation and metastasis. HAO1 could be an appealing therapeutic target for preventing lung metastasis of cancer.

Sustainable consumption is one of the goals of the ‘Sustainable Development Goals 2030′ set by the United Nations. The study is primarily interested in how sustainable consumption behavior can be fostered through environmental knowledge, behaviors, and attitudes. For environmental concern, the role of environmental knowledge is considered significant. Therefore, academia is powered by the desire to impart environmentally friendly attitudes and behaviors to students for sustainable consumption. The main purpose of this study was to measure the influence of environmental knowledge and environmental risk perceptions on the environmental concerns of university students. Likewise, how environmental attitudes act as a moderator in the association between environmental concern and pro-environmental behavior was also taken into account. The unit of analysis was the students enrolled in the universities of China. Following a deductive approach and positivist paradigm, and using SmartPLS, we deployed a structural equation modelling (PLS-SEM) technique to test the relationships. The results exhibited that environmental knowledge and environmental risk perceptions are positively and significantly related with environmental concerns. Similarly, environmental concerns and pro-environmental behavior are positively and significantly related to sustainable consumption behavior. Environmental attitude appeared as a moderator in the relationship between environmental concerns and pro-environmental behavior. The theory of planned behavior was considered as the supporting theory for the investigated model, thereby providing empirical evidence for the theory. The study provided important implications and future directions.

Microneedles (MNs) have attracted considerable attention in the pharmaceutical field as a minimally invasive delivery alternative to hypodermic needles. Current material systems of MNs have gradually shifted from metals, ceramics, and silicon to polymer in consideration of toughness and drug loading capacity. Silk fibroin (SF) is considered one of the most promising alternatives because it combines the ability to maintain the activity of biomolecules, adjustable mechanical strength, and excellent biocompatibility. However, the strength and hardness of SF MNs need to be carefully optimized to ensure skin epidermis penetration and controlled drug release, which are rarely explored in reported works. Here, the synergistic effect of glutaraldehyde-based cross-linking and water vapor annealing post-treatment is presented as an effective method to promote the formation of SF molecular networks and the mechanical strength of SF MNs. Moreover, the reinforced MN substrate is coated with a drug-loaded SF layer with low crystallinity. The drug release experiments demonstrate the successful controlled release of rhodamine B, horseradish peroxidase, and tetracycline, which suggests the great potential in the application of vaccine, antibiosis, cosmetology, and so forth.

In colorectal cancer (CRC), overt metastases often appear after years of latency. But the signals that cause micro-metastatic cells to remain indolent, thereby enabling them to survive for extended periods of time, are unclear. Immunofluorescence and co-immunoprecipitation assays were used to explore the co-localization of CCL7 and CCR2. Immunohistochemical (IHC) assays were employed to detect the characters of metastatic HT29 cells in mice liver. Flow cytometry assays were performed to detect the immune cells. Bruberin vivo MS FX Pro Imager was used to observe the liver metastasis of CRC in mice. Quantitative real-time PCR (qRT-PCR) and western blot were employed to detect the expressions of related proteins. Trace RNA sequencing was employed to identify differentially expressed genes in MDSCs from liver micro-M and macro-M of CRC in mice. Here, we firstly constructed the vitro dormant cell models and metastatic dormant animal models of colorectal cancer. Then we found that myeloid-derived suppressor cells (MDSCs) were increased significantly from liver micro-metastases to macro-metastases of CRC in mice. Moreover, monocytic MDSCs (Mo-MDSC) significantly promoted the dormant activation of micro-metastatic cells compared to polymorphonuclear MDSCs (PMN-MDSC). Mechanistically, CCL7 secreted by Mo-MDSCs bound with membrane protein CCR2 of micro-metastatic cells and then stimulated the JAK/STAT3 pathway to activate the dormant cells. Low-dose administration of CCL7 and MDSCs inhibitors in vivo could significantly maintain the CRC metastatic cells dormant status for a long time to reduce metastasis or recurrence after radical operation. Clinically, the level of CCL7 in blood was positively related to the number of Mo-MDSCs in CCR patients, and highly linked with the short-time recurrence and distant metastasis. CCL7 secreted by Mo-MDSCs plays an important role in initiating the outgrowth of metastatic latent CRC cells. Inhibition of CCL7 might provide a potential therapeutic strategy for the prevention of metastasis recurrence.

Insights of social development, presented in various forms, such as metrics, figures, text summaries, whose purpose is to summarize, explain, and predict the situations and trends of society, is extremely useful to guide organizations and individuals to better realize their own objectives in accordance with the whole society. Deriving these insights accurately and swiftly has become an interest for a range of organizations, including agencies governing districts, city even the whole country, they use these insights to inform policy-makings. Business investors who peak into statistical numbers for estimating current economical situations and future trends. Even for individuals, they could look at some of these insights to better align themselves with macroscopical social trends. There are many challenges to develop these insights in a data-driven approach. First, required data come from a large number of heterogeneous sources in a variety of formats. One single source’s data could be in the size of hundreds of Gigabytes to several TeraBytes, ingesting and governing such huge amount of data is not a small challenge. Second, many complex insights are derived by domain human experts in a trail-and-error fashion, while interacting with data with the aid of computer algorithms. To quickly experiment various algorithms, it asks for software capabilities for infusing human experts and machine intelligence together, this is challenging but critical for success.By designing and implementing a flexible big data stack that could bring in a variety of data components. We address some of the challenges to infuse data, computer algorithm and human together in Zilian Tech company [20]. In this paper we present the architecture of our data stack and articulate some of the important technical choices when building such stack. The stack is designed to be equipped with scalable storage that could scale up to PetaBytes, as well as elastic distributed compute engine with parallel computing algorithms. With these features the data stack enables a) swift data analysis, by human analysts interacting with data and machine algorithms via software support, with on-demand question answering time reduced from days to minutes; b) agile building of data products for end users to interact with, in weeks if not days from months.

Cancer-derived exosomes are considered a major driver of cancer-induced pre-metastatic niche formation at foreign sites, but the mechanisms remain unclear. Here, we show that miR-25-3p, a metastasis-promoting miRNA of colorectal cancer (CRC), can be transferred from CRC cells to endothelial cells via exosomes. Exosomal miR-25-3p regulates the expression of VEGFR2, ZO-1, occludin and Claudin5 in endothelial cells by targeting KLF2 and KLF4, consequently promotes vascular permeability and angiogenesis. In addition, exosomal miR-25-3p from CRC cells dramatically induces vascular leakiness and enhances CRC metastasis in liver and lung of mice. Moreover, the expression level of miR-25-3p from circulating exosomes is significantly higher in CRC patients with metastasis than those without metastasis. Our work suggests that exosomal miR-25-3p is involved in pre-metastatic niche formation and may be used as a blood-based biomarker for CRC metastasis., The mechanisms underlying pre-metastatic niche formation by cancer derived exosomes is unclear. Here they show that colorectal cancer (CRC) derived exosomal miR-25-3p promotes vascular leakiness and angiogenesis, CRC metastasis, and is upregulated in CRC pateints with metastasis, and suggest miR-25-3p as a biomarker for CRC metastasis.

Purpose: To develop a circulating tumor DNA (ctDNA) methylation signature for early detection of metastatic relapse and surveillance of therapeutic efficacy in stage III CRC. Perimental design: The deferentially methylated locations (DMLs) between 52 normal intestinal mucosa and 134 stage III CRC tissue and between plasma from 96 stage I/II CRC patients and 73 stage IV CRC patients were detected by high-throughput targeted methylation sequencing. CtDNA methylation signature was established by random forest with DMLs shared by plasma and tissue samples. This signature was then applied to predict the risk of metastatic disease recurrence in blood samples from 50 stage III CRC patients and dynamic monitor the recurrence risk in serial blood samples from 4 CRC patients. Results: 2237 and 1185 hypermethylation markers were identified in CRC tissue and plasma from stage IV CRC patients, respectively. Our signature achieved the sensitivity of 84.21% and specificity of 81.81% in distinguishing late CRC from early CRC in the validation cohort. Moreover, this signature yielded high sensitivity (87.5%) and specificity (94.12%) for predicting metastatic disease relapse in a cohort of 50 stage III CRC patients, and could be an independent risk factor for relapse in those patients (HR, 18.7; 95% CI, 5.3-66.2; P = 9.86e-6). The analyses of serial blood samples of CRC showed that this model was more sensitive to monitor treatment response than imaging examination and serum carcinoembryonic antigen (CEA). Conclusions: We identify a ctDNA methylation signature for stratifying risk of recurrence in stage III CRC and non-invasively monitoring treatment response.Statement of translational relevanceWe successfully developed a ctDNA methylation signature for risk assessment of metastatic disease recurrence in stage III CRC patients and surveillance of therapeutic efficacy of CRC. Funding: This work was supported by the National Key R&D program of China (2017YFC1309002), National Natural Science Foundation of China (81672821, 81872041, 81773101, 81802306, 81903002), Natural Science Foundation Key program of Guangdong Province of China (2018B0303110017), Natural Science Foundation of Guangdong Province of China (2018A030310457, 2019A1515011436), Science and Technology Planning Project of Guangdong Province, China (2017B020226005). Declaration of Interest: The authors Jianbing Fan, Xia Li are employees of AnchorDx Medical Co., Ltd., a company that focuses on the development of next generation sequencing diagnostic products for cancer detection using liquid biopsy. All other authors declare no competing financial interest. Ethical Approval: It was approved by the Human Research Ethical Review Board in Southern Hospital of Southern Medical University and Southern Theater General Hospital of Chinese people's Liberation Army.

Patients with colorectal cancer (CRC) often develop malignant regrowth of metastatic dormant tumor cells in liver years after primary treatment. FBX8 is involved in suppressing tumor metastasis. Short-term chemotherapy experiments and liver metastasis mice model of orthotopic injection into the cecum were performed to construct the dormant models. GST-pull-down assay, Co-IP and immunofluorescence were used to confirm the bindings among FBX8 and its substrates. FBX8 upregulated the expression of epithelial and stemness markers, while downregulated the expression of mesenchymal and proliferative markers associated with tumor cell dormancy. FBX8 promoted the maintenance of metastatic dormancy of CRC cells. Mechanistically, FBX8 directly bound to HIF-1α, CDK4 and C-myc through its Sec7 domain and led to the ubiquitin degradation of these proteins, thereby inhibiting cell cycle progression, proliferation, angiogenesis, and metastasis. Clinically, FBX8 expression was negatively correlated with the HIF-1α, CDK4, and c-Myc in CRC tissues. Our study reveals a novel mechanism of FBX8 in regulating tumor metastatic dormancy in liver and provides new strategies for the treatment of CRC metastasis.

Visible-infrared person re-identification (VI-ReID) is a significant technology in night-time surveillance applications. Compared to traditional person re-identification that focuses on only visible imaging system, the modality discrepancy between infrared and visible images brings an additional challenge to VI-ReID. Taking the shortcomings of existing VI-ReID works in terms of feature representation into account, in this paper, we propose an end-to-end network named Joint Feature Learning Network (JFLN) to jointly utilize global and local features, high-level and middle-level features, as well as shared and specific features. In addition, based on these extracted features, we introduce a multi-loss supervision strategy in the training process. Extensive experiments conducted on public SYSU-MM01 dataset demonstrate that the proposed method outperforms the state-of-the-arts, with relatively less computational cost.

Radioresistance hampers success in the treatment of patients with advanced colorectal cancer (CRC). Improving our understanding of the underlying mechanisms of radioresistance could increase patients’ response to irradiation (IR). MicroRNAs are a class of small RNAs involved in tumor therapy response to radiation. Here we found that miR-214 was markedly decreased in CRC cell lines and blood of CRC patients after IR exposure. Meanwhile, autophagy was enhanced in irradiated CRC cells. Mechanically, ATG12 was predicted and identified as a direct target of miR-214 by dual luciferase assay, qPCR, and Western blot. In vitro and in vivo experiments showed that miR-214 promoted radiosensitivity by inhibiting IR-induced autophagy. Restoration of ATG12 attenuated miR-214-mediated inhibition of cell growth and survival in response to IR. Importantly, miR-214 was highly expressed in radiosensitive CRC specimens and negatively correlated with plasma level of CEA. Moreover, ATG12 and LC3 expressions were increased in radioresistant CRC specimens. Our study elucidates that miR-214 promotes radiosensitivity by inhibition of ATG12-mediated autophagy in CRC. Importantly, miR-214 is a determinant of CRC irradiation response and may serve as a potential therapeutic target in CRC treatment.

Background: Diaphanous-related formins (DRFs), actin necleator, have been known to participate in the progression of cancer cells. We previously reported that FMNL2 (Formin-like2), a member of DRFs, was a positive regulator in colorectal cancer (CRC) metastasis, yet proteins and pathways required for the function of this pro-invasive DRFs remain to be identified. Methods: The relationship between FMNL2 and COMMD10 was examined using Co-IP, GST pull-down, immunofluorescence and in vitro ubiquitination assay. The in vitro and in vivo function of COMMD10 in CRC was evaluated using CCK-8 proliferation assay, plate colony formation, cell cycle, apoptosis and animal models. The inhibition of NF-κB signalling by COMMD10 was detected using dual-luciferase reporter assay and western blotting. Co-IP, GST pull-down and nuclear protein extraction assay were performed to evaluate the effect on p65 by COMMD10. Real-time PCR and western blotting were performed to detect expressions of FMNL2, COMMD10 and p65 in paired tissues. Results: FMNL2 targets COMMD10 for ubiquitin-mediated proteasome degradation in CRC cells. COMMD10 targets p65 NF-κB (nuclear factor-κB) subunit and reduces its nuclear translocation, thereby leading to the inactivation of NF-κB pathway and suppression of CRC invasion and metastasis. Inhibition of NF-κB signalling by COMMD10 is necessary for FMNL2-mediated CRC cell behaviours. Downregulation of COMMD10 predicts poor prognosis of CRC patients. The expressions of FMNL2, COMMD10 and p65 are highly linked in CRC tissues. Conclusions: These data demonstrate that the FMNL2/COMMD10/p65 axis acts as a critical regulator in the maintenance of metastatic phenotypes and is strongly associated with negative clinical outcomes.

F-box proteins are critical components of the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligases and involved in the ubiquitin-dependent proteolytic pathway. Dysregulation of F-box protein-mediated proteolysis often leads to human malignancies. F-box only protein 8 (FBX8), a novel component of F-box proteins, is down-regulated in several tumors and closely correlates with tumor progression. However, little is known about its function, regulatory mechanisms and substrates in the progression of colorectal carcinoma (CRC). Combining microRNA (miRNA) assay, functional characterization, mechanistic studies with clinical validation, we identify FBX8 as a CRC metastasis suppressor downstream of miR-223, a metastasis promoting miRNA that is transcriptionally regulated by Myocyte enhancer factor (MEF2A). mTOR is a substrate of FBX8 for ubiquitin-mediated degradation and is required for FBX8 induced cell proliferation and invasion in CRC cells. FBX8 is down-regulated in human CRC tissues and correlates with MEF2A, miR-223 and mTOR expression levels. Notably, low FBX8 expression status in CRC tissues was a significant prognostic factor for poor overall survival of patients. These findings illustrate FBX8 as a metastasis suppressor that functions through mTOR signaling pathway and has significant prognostic power.

Background Cancer associated fibroblasts (CAFs) are key stroma cells that play dominant roles in tumor progression. However, the CAFs-derived molecular determinants that regulate colorectal cancer (CRC) metastasis and chemoresistance have not been fully characterized. Methods CAFs and NFs were obtained from fresh CRC and adjacent normal tissues. Exosomes were isolated from conditioned medium and serum of CRC patients using ultracentrifugation method and ExoQuick Exosome Precipitation Solution kit, and characterized by transmission electronic microscopy, nanosight and western blot. MicroRNA microarray was employed to identify differentially expressed miRNAs in exosomes secreted by CAFs or NFs. The internalization of exosomes, transfer of miR-92a-3p was observed by immunofluorescence. Boyden chamber migration and invasion, cell counting kit-8, flow cytometry, plate colony formation, sphere formation assays, tail vein injection and primary colon cancer liver metastasis assays were employed to explore the effect of NFs, CAFs and exosomes secreted by them on epithelial-mesenchymal transition, stemness, metastasis and chemotherapy resistance of CRC. Luciferase report assay, real-time qPCR, western blot, immunofluorescence, and immunohistochemistry staining were employed to explore the regulation of CRC metastasis and chemotherapy resistance by miR-92a-3p, FBXW7 and MOAP1. Results CAFs promote the stemness, epithelial-mesenchymal transition (EMT), metastasis and chemotherapy resistance of CRC cells. Importantly, CAFs exert their roles by directly transferring exosomes to CRC cells, leading to a significant increase of miR-92a-3p level in CRC cells. Mechanically, increased expression of miR-92a-3p activates Wnt/β-catenin pathway and inhibits mitochondrial apoptosis by directly inhibiting FBXW7 and MOAP1, contributing to cell stemness, EMT, metastasis and 5-FU/L-OHP resistance in CRC. Clinically, miR-92a-3p expression is significantly increased in CRC tissues and negatively correlated with the levels of FBXW7 and MOAP1 in CRC specimens, and high expression of exosomal miR-92a-3p in serum was highly linked with metastasis and chemotherapy resistance in CRC patients. Conclusions CAFs secreted exosomes promote metastasis and chemotherapy resistance of CRC. Inhibiting exosomal miR-92a-3p provides an alternative modality for the prediction and treatment of metastasis and chemotherapy resistance in CRC. Electronic supplementary material The online version of this article (10.1186/s12943-019-1019-x) contains supplementary material, which is available to authorized users.

Background: Hepatocellular carcinoma (HCC) patients diagnosed with the same clinic stage by Barcelona Clinic Liver Cancer (BCLC) system show different prognosis due to coexistence of inflammation and tumor heterogeneity. Here, we aimed to seek for inflammation-related molecular biomarkers for accurately predicting diagnosis and prognosis of HCC. Methods: In this multicenter and retrospective analysis, we included 516 patients with HCC from three Chinese hospitals: Nanfang Hospital (Guangzhou, China), Zhujiang Hospital (Guangzhou, China) and Yuebei Hospital (Shaoguan, China). COMMD10 was screened out from inflammation-induced HCC using real-time PCR analysis. Nomogram based on COMMD10 and BCLC stage was established and validated. The predictive accuracy and discriminative ability of the nomogram was determined by concordance index and calibration curve. The primary endpoint was overall survival (OS). In vitro and in vivo assays were performed to investigate the role of COMMD10 in HCC. The potential molecular mechanisms of COMMD10 were determined by luciferase assay, immunofluorescence, immunoprecipitation. Findings: The nomogram based on COMMD10 and BCLC stage yielded more accuracy than BCLC stage alone for predicting OS of HCC patients in multicenter cohorts. COMMD10 can stratify early-stage HCC (BCLC stage 0 and A) patients into two risk groups with significantly different OS. Mechanistically, COMMD10 suppressed proliferation in vitro and in vivo by interacting with Rel homology domain of p65 and potentiating apoptosis by modulating Bcl-2/Bax/caspase-9/3 pathway in HCC. Interpretation: COMMD10 is a powerful prognostic biomarker and values up BCLC staging to predict OS for HCC, especially for identifying early-stage HCC patients who could benefit from individual therapy. Funding Statement: This work was supported by the National Natural Science Foundation of China [NO.81672992,81602685]; the Natural Science Foundation of Guangdong Province [NO. 2017A030313486]. Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: This study was approved by the Ethics Committee of Nanfang Hospital of Southern Medical University, and all participants provided written informed consent prior to surgery. It also conforms to the provisions of the Declaration of Helsinki.

// Huijun Xie 1, 2, 3, * , Xiaoli Ren 1, 2, 3, * , Sainan Xin 1, 2, 3, * , Xiaoliang Lan 4 , Guifeng Lu 1, 2, 3 , Yuan Lin 1, 2, 3 , Shaoshan Yang 1, 2, 3 , Zhicheng Zeng 1, 2, 3 , Wenting Liao 1, 2, 3 , Yan-Qing Ding 1, 2, 3 , Li Liang 1, 2, 3 1 Department of Pathology, Nanfang Hospital, Guangzhou, Guangdong, China 2 Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China 3 Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China 4 Department of General Surgery, Nanfang Hospital, Guangzhou, Guangdong, China * These authors contributed equally to this work Correspondence to: Li Liang, email: redsnow007@hotmail.com Yan-Qing Ding, email: dyq@fimmu.com Keywords: hsa_circ_001569, miR-145, colorectal cancer, FMNL2, BAG4 Received: December 08, 2015 Accepted: March 07, 2016 Published: April 05, 2016 ABSTRACT Circular RNAs (circRNAs), a large class of RNAs, have recently shown huge capabilities as gene regulators in mammals. Some of them bind with microRNAs (miRNAs) and act as natural miRNA sponges to inhibit related miRNAs’ activities. Here we showed that hsa_circ_001569 acted as a positive regulator in cell proliferation and invasion of colorectal cancer (CRC). Moreover, hsa_circ_001569 was identified as a sponge of miR-145 and up-regulated miR-145 functional targets E2F5, BAG4 and FMNL2. In CRC tissues, circ_001569 negatively correlated with miR-145, and miR-145 correlated negatively with E2F5, BAG4 and FMNL2 expressions. Our study reveals a novel regulatory mechanism of circ_001569 in cell proliferation and invasion in CRC, provides a comprehensive landscape of circ_001569 that will facilitate further biomarker discoveries in the progression of CRC.

A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly(L-lactide-co-glycolide)(PLGA) with chitosan and hydroxyapatite(HA). The poly(L-lactide-co-glycolide)/chitosan/hydroxyapatite (PLGA/chitosan/HA) conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50-100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery.

In recent years, Wi-Fi has seen extraordinary growth; however, due to the cost, performance and security issues, many Wi-Fi hotspot owners would like to restrict the network access only to individuals inside the physical property. Unfortunately, due to the nature of wireless, this is difficult to accomplish, especially with the off-the-shelf omni-antenna devices. In this work, we develop and implement CLaWa, a Crowdsourced Location Aware Wi-Fi Access Control scheme to address this challenge. Our system is based on observations of differing characteristics of physical layer information across physical boundaries such as walls and corners. CLaWa crowdsources both channel state information (CSI) and received signal strength (RSS) of already validated users to classify future users. We have also selected an appropriate machine learning algorithm for CLaWa. Evaluation results show that CLaWa can identify the boundary around a given area precisely, thus granting network access only to users inside the area while not validating users outside the boundary. Compared to indoor localization schemes, CLaWa is a lightweight solution which does not require expensive localization operations.

Many existed physical layer based schemes have been proposed to enhance the traditional authentication in wireless networks. However earlier schemes did not discuss directional antenna issue, and lacked of real measurement based evaluation. In this paper, we take an insight into the threat of directional antenna on physical layer authentication by real measurement observation. We give a brief overview of the mainstream physical layer authentication schemes, and build a real-time experimental platform to collect the channel state information, and evaluate the performance of some mainstream schemes by collecting real data in different typical environments, especially in the situation when the attacker uses directional antenna. We show the physical layer authentication schemes are effective in most cases, but may fail to detect the third party attacker equipped with directional antenna. Based on our discovery, we suggest that directional antenna impact should be seriously considered in physical layer based applications, especially in security domain.

Handheld and non-handheld devices, which are simultaneously online, constitute the regular clients of the campus wireless local area networks (WLAN). It is necessary to understand the patterns of the user distribution and the user behavior, and adopt better strategies to optimize the service, as well as to understand the students' daily life. This paper introduces a approach of understanding how campus WLAN performs and how the users behave. In the analysis, many interesting phenomenons and problems are discovered. We capture all of the packets in a campus free Wi-Fi during the experimental period. We articulate an approach to describe the user distribution from the view of the traffic variation tendency and the network performance. And the user behavior patterns are described from two aspects, the popular websites and the behavior of downloading files. Furthermore, after revealing the problems of the network, practical suggestions is proposed for improvements in different aspects.

Magnetic flux ropes are highly twisted, current-carrying magnetic fields. They are crucial for the instability of plasma involved in solar eruptions, which may lead to adverse space weather effects. Here we present observations of a flaring using the highest resolution chromospheric images from the 1.6-m New Solar Telescope at Big Bear Solar Observatory, supplemented by a magnetic field extrapolation model. A set of loops initially appear to peel off from an overall inverse S-shaped flux bundle, and then develop into a multi-stranded twisted flux rope, producing a two-ribbon flare. We show evidence that the flux rope is embedded in sheared arcades and becomes unstable following the enhancement of its twists. The subsequent motion of the flux rope is confined due to the strong strapping effect of the overlying field. These results provide a first opportunity to witness the detailed structure and evolution of flux ropes in the low solar atmosphere., Understanding the behaviour of magnetic flux ropes in the Sun is crucial for explaining solar phenomena such as flares and space weather. Exploiting the high resolution available in the 1.6 m New Solar Telescope, Wang et al. capture the evolution of a flaring twisted flux rope in the low solar corona.

On June 17, 2012, we observed the evolution of a C-class flare associated with the eruption of a filament near a large sunspot in the active region NOAA 11504. We obtained high spatial resolution filtergrams using the 1.6 m New Solar Telescope at the Big Bear Solar Observatory in broad-band TiO at 706 nm (bandpass:10 \AA) and He I 10830 \AA\ narrow-band (bandpass: 0.5 \AA, centered 0.25 \AA\ to the blue). We analyze the spatio-temporal behavior of the He I 10830 \AA\ data, which were obtained over a 90" X 90" field of view with a cadence of 10 sec. We also analyze simultaneous data from the Atmospheric Imaging Assembly and Extreme Ultraviolet Variability Experiment instruments on board the Solar Dynamics Observatory spacecraft, and data from Reuven Ramaty High Energy Solar Spectroscopic Imager and GOES spacecrafts. Non-thermal effects are ignored in this analysis. Several quantitative aspects of the data, as well as models derived using the "0D" Enthalpy-Based Thermal Evolution of Loops model (EBTEL: Klimchuk et al. 2008) code, indicate that the triplet states of the 10830 \AA\ multiplet are populated by photoionization of chromospheric plasma followed by radiative recombination. Surprisingly, the He II 304 \AA\ line is reasonably well matched by standard emission measure calculations, along with the C IV emission which dominates the AIA 1600 \AA\ channel during flares. This work lends support to some of our previous work combining X-ray, EUV and UV data of flares to build models of energy transport from corona to chromosphere.

Large-scale spectral clustering in high-dimensional space is among the most popular unsupervised problems. Existed sampling schemes have different limitations on high-dimensional data. This paper proposes an improved Nystrom extension based spectral clustering algorithm with a designed sampling scheme for high-dimensional data. We first take insight into some existed sampling schemes. We illustrate their defects especially in high dimension scene. Furthermore we provide theoretical analysis on how the similarity between the sample set and non-sampling set influences the approximation error, and propose an improved sampling scheme, the minimum similarity sampling MSS for high-dimensional space clustering. Experiments on both synthetic and real datasets show that the proposed sampling scheme outperforms other algorithms when applied in Nystrom based spectral clustering with higher accuracy, and lowers the time consumption for sampling.

In this paper, we report our first-step results of high resolution He I 10830 angstrom narrow-band imaging (bandpass: 0.5 angstrom) of an M1.8 class two-ribbon flare on 2012 July 5. The flare was observed with the 1.6 m aperture New Solar Telescope at Big Bear Solar Observatory. For this unique data set, sunspot dynamics during flaring were analyzed for the first time. By directly imaging the upper chromosphere, running penumbral waves are clearly seen as an outward extension of umbral flashes; both take the form of absorption in the 10830 angstrom narrow-band images. From a space-time image made of a slit cutting across a flare ribbon and the sunspot, we find that the dark lanes for umbral flashes and penumbral waves are obviously broadened after the flare. The most prominent feature is the sudden appearance of an oscillating absorption strip inside the ribbon when it sweeps into the sunspot's penumbral and umbral regions. During each oscillation, outwardly propagating umbral flashes and subsequent penumbral waves rush out into the inwardly sweeping ribbon, followed by a return of the absorption strip with similar speed. We tentatively explain the phenomena as the result of a sudden increase in the density of ortho-helium atoms in the area of the sunspot being excited by the flare's extreme ultraviolet illumination. This explanation is based on the observation that 10830 angstrom absorption around the sunspot area gets enhanced during the flare. Nevertheless, questions are still open and we need further well-devised observations to investigate the behavior of sunspot dynamics during flares.

This Letter reports two rarely observed three-ribbon flares (M1.9 and C9.2) on 2012 July 6 in NOAA AR 11515, which we found using Hα observations of 01 resolution from the New Solar Telescope and Ca II H images from Hinode. The flaring site is characterized by an intriguing "fish-bone-like" morphology evidenced by both Hα images and a nonlinear force-free field (NLFFF) extrapolation, where two semi-parallel rows of low-lying, sheared loops connect an elongated, parasitic negative field with the sandwiching positive fields. The NLFFF model also shows that the two rows of loops are asymmetric in height and have opposite twists, and are enveloped by large-scale field lines including open fields. The two flares occurred in succession within half an hour and are located at the two ends of the flaring region. The three ribbons of each flare run parallel to the magnetic polarity inversion line, with the outer two lying in the positive field and the central one in the negative field. Both flares show surge-like flows in Hα apparently toward the remote region, while the C9.2 flare is also accompanied by EUV jets possibly along the open field lines. Interestingly, the 12-25 keV hard X-ray sources of the C9.2 flare first line up with the central ribbon then shift to concentrate on the top of the higher branch of loops. These results are discussed in favor of reconnection along the coronal null line, producing the three flare ribbons and the associated ejections.