Microstructure and property evolution of diamond-like carbon films co-doped by Al and Ti with different ratios

Zhou, Yong,Guo, Peng,Sun, Lili,Liu, Linlin,Xu, Xiaowei,Li, Wenxian,Li, Xiaowei,Lee, Kwang-Ryeol,Wang, Aiying Elsevier Sequoia 2019 Surface & coatings technology Vol.361 No.-

<P><B>Abstract</B></P> <P>Diamond-like carbon (DLC) films with weak carbide metal Al and carbide metal Ti co-doping (Al/Ti-DLC) were prepared by a hybrid ion beam deposition system. The atomic ratios of doped Al to Ti were tailored via designing the special Al/Ti combined sputtering target. The composition, microstructure, roughness, residual stress, hardness, toughness, and tribological behaviors of the deposited films were systematically evaluated to explore the dependence of structural properties on Al/Ti ratios. Results indicated that the high-throughput preparation of DLC films with different Al/Ti atomic ratios was achieved by tailoring the sputtering target and process parameters without the difference in both the film thickness and total Al/Ti content. With the Al/Ti ratios in the films decreased from 8.8 to 3.0, the residual stress, hardness, and toughness of Al/Ti-DLC films increased obviously, originating from the increased fraction of titanium carbide and the reduced Al content. However, the coefficient of friction and wear rate with decreasing the Al/Ti ratio were obviously improved, which was related with the transformation of underlying friction mechanism from the sliding interface graphitization to dangling bond-passivation. The present results not only suggest a high-throughput method to fabricate co-doped DLC films, but also promote the scientific understanding and engineering application of DLC films with high performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. </LI> <LI> Different Al/Ti ratios were successfully achieved at one time using designed target. </LI> <LI> Al/Ti ratios had no effect on the chemical state of co-doped Ti and Al atoms. </LI> <LI> The mechanical and tribological properties were strongly dependent on Ti/Al ratios. </LI> <LI> Different friction mechanisms were observed with Al/Ti ratios ranged from 8.8 to 3.0. </LI> </UL> </P>

Adsorption of zinc (Ⅱ), cadmium (Ⅱ), and copper (Ⅱ) with PTFE Selective Resin containing primary amine N1923 and Cyanex925

Xiaowei Zhao,Weihong Zhou,Qiong Jia 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6

In the present study, a synergistic extraction mixture, primary amine N1923 (RNH2) and Cyanex925 (B), was loaded on PTFE powder to prepare PTFE Selective Resin and was employed for the adsorption of zinc, cadmium, and copper from chloride medium. The effects of shaking time, resin amounts, concentration of metal ions, and experimental temperature on the distribution coefficients were determined. The stoichiometry of the adsorbed complexes was determined to be MCl2·(1/2)RNH2·B with the Selective Resin. The equilibrium constants and thermodynamic quantities (ΔH, ΔG, and ΔS) were calculated. Furthermore, the Freundlich isotherm proved to be more suitable than the Langmuir isotherm to indicate the effect of concentration of M2+ on the adsorption with PTFE Selective Resin.

Secure Connectivity Probability of Multi-hop Clustered Randomize-and-Forward Networks

Xiaowei Wang,Zhou Su,Guangyi Wang 한국전자통신연구원 2017 ETRI Journal Vol.39 No.5

This work investigates secure cluster-aided multi-hop randomize-and-forward networks. We present a hop-by-hop multi-hop transmission scheme with relay selection, which evaluates for each cluster the relays that can securely receive the message. We propose an analytical model to derive the secure connectivity probability (SCP) of the hop-by-hop transmission scheme. For comparison, we also analyze SCPs of traditional end-to-end transmission schemes with two relay-selection policies. We perform simulations, and our analytical results verify that the proposed hop-by-hop scheme is superior to end-to-end schemes, especially with a large number of hops or high eavesdropper channel quality. Numerical results also show that the proposed hop-by-hop scheme achieves near-optimal performance in terms of the SCP.

Endoscopic Submucosal Tunnel Dissection for Upper Gastrointestinal Submucosal Tumors Originating from the Muscularis Propria Layer: A Single-Center Study

( Xiaowei Tang ),( Yutang Ren ),( Silin Huang ),( Qiaoping Gao ),( Jieqiong Zhou ),( Zhengjie Wei ),( Bo Jiang ),( Wei Gong ) 대한간학회 2017 Gut and Liver Vol.11 No.5

Background/Aims: In recent years, endoscopic submucosal tunnel dissection (ESTD) has gained popularity worldwide. The aim of this study was to evaluate the safety and efficacy of ESTD in treating upper gastrointestinal submucosal tu-mors (SMTs) in a large-volume endoscopic center. Methods: Patients with SMTs were enrolled in this study between January 2012 and January 2015. Demographic data, clinical data, and treatment outcome were collected and analyzed. Results: Seventy SMTs originating from the muscularis pro-pria (MP) layer were identified in 69 patients. All patients successfully underwent the ESTD procedure. The mean procedure time was 49.0±29.5 minutes, and the mean tu-mor size was 18.7±7.2 mm. Among all lesions, the majority (70.0%) were located in the esophagus, 12.9% in the cardia, and 17.1% in the stomach. Complete resection was achieved in 67 lesions (95.7%). Perforation occurred in three patients (4.3%), who were treated by endoclips. Pneumothorax oc-curred in two patients (2.9%) and was successfully managed by thoracic drainage. During a median follow-up of 18.1 months, patients were free of local recurrence or distant metastasis. Conclusions: Our results demonstrated the fea-sibility and safety of ESTD in treating upper gastrointestinal SMTs originating from the MP layer. Large-scale comparative studies with other treatment methods should be conducted in the future. (Gut Liver 2017;11:620-627)

TRIM22 promotes the proliferation of glioblastoma cells by activating MAPK signaling and accelerating the degradation of Raf-1

Fei Xiaowei,Dou Ya-nan,Sun Kai,Wei Jialiang,Guo Qingdong,Wang Li,Wu Xiuquan,Lv Weihao,Jiang Xiaofan,Fei Zhou 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The tripartite motif (TRIM) 22 and mitogen-activated protein kinase (MAPK) signaling pathways play critical roles in the growth of glioblastoma (GBM). However, the molecular mechanism underlying the relationship between TRIM22 and MAPK signaling remains unclear. Here, we found that TRIM22 binds to exon 2 of the sphingosine kinase 2 (SPHK2) gene. An ERK1/2-driven luciferase reporter construct identified TRIM22 as a potential activator of MAPK signaling. Knockout and overexpression of TRIM22 regulate the inhibition and activation of MAPK signaling through the RING-finger domain. TRIM22 binds to Raf-1, a negative regulator of MAPK signaling, and accelerates its degradation by inducing K48-linked ubiquitination, which is related to the CC and SPRY domains of TRIM22 and the C1D domain of Raf-1. In vitro and in vivo, an SPHK2 inhibitor (K145), an ERK1/2 inhibitor (selumetinib), and the nonphosphorylated mutant Raf-1S338A inhibited GBM growth. In addition, deletion of the RING domain and the nuclear localization sequence of TRIM22 significantly inhibited TRIM22-induced proliferation of GBM cells in vivo and in vitro. In conclusion, our study showed that TRIM22 regulates SPHK2 transcription and activates MAPK signaling through posttranslational modification of two critical regulators of MAPK signaling in GBM cells.

Experimental investigations on detecting lateral buckling for subsea pipelines with distributed fiber optic sensors

Jing Zhou,Xin Feng,Wenjing Wu,Xingyu Li,Xiaowei Zhang 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.2

A methodology based on distributed fiber optic sensors is proposed to detect the lateral buckling for subsea pipelines in this study. Uncontrolled buckling may lead to serious consequences for the structural integrity of a pipeline. A simple solution to this problem is to control the formation of lateral buckles among the pipeline. This firms the importance of monitoring the occurrence and evolution of pipeline buckling during the installation stage and long-term service cycle. This study reports the experimental investigations on a method for distributed detection of lateral buckling in subsea pipelines with Brillouin fiber optic sensor. The sensing scheme possesses the capability for monitoring the pipeline over the entire structure. The longitudinal strains are monitored by mounting the Brillouin optical time domain analysis (BOTDA) distributed sensors on the outer surface of the pipeline. Then the bending-induced strain is extracted to detect the occurrence and evolution of lateral buckling. Feasibility of the method was validated by using an experimental program on a small scale model pipe. The results demonstrate that the proposed approach is able to detect, in a distributed manner, the onset and progress of lateral buckling in pipelines. The methodology developed in this study provides a promising tool for assessing the structural integrity of subsea pipelines

Does Internet Use Promote or Inhibit Social Capital? Empirical Evidence from the 2017 Chinese General Social Survey

Min Zhou,Xiaowei Ning 서울대학교 사회발전연구소 2022 Journal of Asian Sociology Vol.51 No.3

This study examines what types of Internet use are related to social capital in today’s China, using data from the 2017 Chinese General Social Survey. It distinguishes the intensity (the time spent on the Internet) and five types (communication, publicity, entertainment, information, and business) of Internet use and investigates their relationships with two distinct types of social capital—network capital and participatory capital that stress interpersonal networks and participation in social organizations, respectively. The intensity of Internet use shows a curvilinear relationship with network capital but displays no relationship with participatory capital. On average, its positive relationship with network capital turns negative after the threshold of 18.6 hours per week. Internet use for communication, publicity, and business is positively related to network capital, and that for publicity and business is positively related to participatory capital. Using the Internet for information and entertainment shows no relationship with either network or participatory capital.

Preparation and characterization of Cu2FeSnS4 thin films for solar cells via a co-electrodeposition method

Jicheng Zhou,Shiqi Yu,Xiaowei Guo,Liang Wu,Hongjiang Li 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Quaternary stannite semiconductor Cu2FeSnS4 (CFTS), which is an ideal material for solar photovoltaic cells, has attracted widespread attention. CFTS crystals have been successfully synthesized by the co-electrochemical deposition method. The structure, morphology, and composition of as-synthesized samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), respectively. From the results, it was found that the properties of the sample can be improved by tuning the Cu2+ concentration in the electrolyte, and the best sample was obtained with the Cu2+ concentration of 0.01 M. For the best sample, the CFTS thin films have single phase and good crystallinity with even particle size. By the addition of ascorbic acid, an effective way has been found to enhance the Fe content in the sample, and the reason for the Fe-poor phenomenon has also been explored.

Proportional-Fair Downlink Resource Allocation in OFDMA-Based Relay Networks

Chang Liu,Xiaowei Qin,Sihai Zhang,Wuyang Zhou 한국통신학회 2011 Journal of communications and networks Vol.13 No.6

In this paper, we consider resource allocation with proportional fairness in the downlink orthogonal frequency division multiple access relay networks, in which relay nodes operate in decode-and-forward mode. A joint optimization problem is formulated for relay selection, subcarrier assignment and power allocation. Since the formulated primal problem is nondeterministic polynomial time-complete, we make continuous relaxation and solve the dual problem by Lagrangian dual decomposition method. A near-optimal solution is obtained using Karush-Kuhn-Tucker conditions. Simulation results show that the proposed algorithm provides superior system throughput and much better fairness among users comparing with a heuristic algorithm.

Simotang Alleviates the Gastrointestinal Side Effects of Chemotherapy by Altering Gut Microbiota

( Lijing Deng ),( Xingyi Zhou ),( Zhifang Lan ),( Kairui Tang ),( Xiaoxu Zhu ),( Xiaowei Mo ),( Zongyao Zhao ),( Zhiqiang Zhao ),( Mansi Wu ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

Simotang oral liquid (SMT) is a traditional Chinese medicine (TCM) consisting of four natural plants and is used to alleviate gastrointestinal side effects after chemotherapy and functional dyspepsia (FD). However, the mechanism by which SMT helps cure these gastrointestinal diseases is still unknown. Here, we discovered that SMT could alleviate gastrointestinal side effects after chemotherapy by altering gut microbiota. C57BL/6J mice were treated with cisplatin (DDP) and SMT, and biological samples were collected. Pathological changes in the small intestine were observed, and the intestinal injury score was assessed. The expression levels of the inflammatory factors IL-1β and IL-6 and the adhesive factors Occludin and ZO-1 in mouse blood or small intestine tissue were also detected. Moreover, the gut microbiota was analyzed by high-throughput sequencing of 16S rRNA amplicons. SMT was found to effectively reduce gastrointestinal mucositis after DDP injection, which lowered inflammation and tightened the intestinal epithelial cells. Gut microbiota analysis showed that the abundance of the anti-inflammatory microbiota was downregulated and that the inflammatory microbiota was upregulated in DDP-treated mice. SMT upregulated antiinflammatory and anticancer microbiota abundance, while the inflammatory microbiota was downregulated. An antibiotic cocktail (ABX) was also used to delete mice gut microbiota to test the importance of gut microbiota, and we found that SMT could not alleviate gastrointestinal mucositis after DDP injection, showing that gut microbiota might be an important mediator of SMT treatment. Our study provides evidence that SMT might moderate gastrointestinal mucositis after chemotherapy by altering gut microbiota.