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In cognitive radios, the biggest challenge is spectrum sensing. It usually makes use of the amplitude, frequency or space dimension of the received signal to differentiate signal from background noise. Polarization, also as an inherent characteristic of signals, provides an additional degree of freedom in signal space. Polarization-based spectrum sensing has been identified as an effective method for improving detection performance. In this paper, various polarization-based spectrum sensing methods including the optimal polarization likelihood ratio test using Neyman-Pearson theorem, virtual polarization detection utilizing maximum signal to noise ratio method and blind polarization detectors based on generalized likelihood ratio test method are reviewed. Then, a comprehensive comparison of various polarization-based sensing methods in terms of detection performance and computational complexity is detailed. Finally, challenges and possible future studies on polarization-based spectrum sensing are described. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

OBJECTIVE: In this study, we investigated whether circulating microRNA-137 (miR-137) could be a potential biomarker for patients with glioblastoma (GBM). PATIENTS AND METHODS: Serum samples were collected from 64 GBM patients and 64 healthy controls. The expression level of circulating miR-137 was compared by quantitative RT-PCR. Among GBM patients, circulating miR-137 was compared between patients at early stages and those at advanced stages. Also, the correlations of serum miR-137 expression with clinicopathological features and overall survival of GBM patients were statistically examined. Furthermore, whether circulating miR-137 could serve as an independent predicting biomarker GBM patients' survival was assessed. RESULTS: Serum miR-137 was downregulated in GBM patients than in healthy controls. It was further downregulated in GBM patients at advanced stages than in patients at early stages. Statistical analysis demonstrated that low serum miR-137 level was strongly correlated with patients' clinical grades (p = 0.003) and KFS (p = 0.002). Low serum miR-137 was also found to be significantly correlated with, and may predict poor survival in GBM patients. CONCLUSIONS: Downregulated serum miR-137 may be a potential non-invasive prognostic biomarker for poor prognosis in GBM patients. [ABSTRACT FROM AUTHOR]

The door-opening task is a key step for the indoor rescue and monitoring of a mobile manipulator. However, the contact effect between the gripper and the door handle may produce excessive internal forces to damage mechanical devices because of position errors or the imprecise modelling of the robot and operation environment. To successfully suppress the excessive internal forces and assure the proper posture of the mobile manipulator under holonomic and non-holonomic constraints, a robust adaptive position/force control algorithm was proposed to track the desired posture and force in opening a door to avoid the complexity of compliant mechanism and the unpredictability of the contact stiffness in traditional impedance control. Dynamic simulation studies with MATLAB and RecurDyn were used to verify the dynamic model of the system and obtain the expected positions and forces during door opening. Simulation results and experiments show that the proposed method is robust in modelling errors, joint frictions and environment disturbances and meets the requirement for opening a door with a handle and suppressing excessive internal forces. This study offers reference data and the control method for future real-world door-opening operation in different environments. [ABSTRACT FROM AUTHOR]

Aims To identify the contributions of various mechanical factors related to cast posts in a root filled tooth by integration of finite element analysis and the Taguchi method. The investigated factors included post-length (Post-L), post-diameter (Post-D), ferrule height (Ferrule-H) and periodontal bone loss (Bone-H). Methodology Three-dimensional finite element models of a mandibular premolar were developed to simulate a root filled tooth. For each investigated factor, three levels and values were selected, and based on a Taguchi orthogonal array, nine models were established. An inclination load of 100 N was applied on the buccal cusp tip, and the dentine peak von Mises stress was used as the evaluation index. Results Among the four investigated factors, Bone-H was the predominant mechanical factor, with a contribution of more than 97%. Among the other three controllable factors of post-design, Post-D was the primary contributing factor and was almost five times more substantial than the least contributing factor, Ferrule-H. Conclusion Bone-H was the predominant factor influencing the stress of the dentine on a post-restored root filled tooth, followed by the Post-D, Post-L and Ferrule-H. For patients with severe periodontal bone loss, a large post-diameter is essential for endodontic post-restoration treatment. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To study the clinical effects and immunologic mechanism of infant capillary bronchitis secondary bronchial asthma treated with bacterial lysates (Broncho-Vaxom OM-85BV). PATIENTS AND METHODS: Between February 2013 and February 2014, 136 infant capillary bronchitis secondary bronchial asthma cases were chosen. This research was approved by Ethics Committee in our hospital and obtained the informed consent right from patients and guardians. Patients were divided into the control group (n = 62) and the observation group (n = 74) using random number table method. Patients in the control group were treated with normal glucocorticoid atomizing inhalation, aminophylline and antibiotic treatment. In the observation group besides the abovementioned treatment, we added Broncho-Vaxom OM-85BV, qd po for 10 days continuously and quitted it for 20 days. This continued for a total of 3 months. Follow- ups were set for about one year to compare the effects. RESULTS: The onset frequency and duration of capillary bronchitis and asthma in observation group declined remarkably compared with control group and the differences were statistically significant (p < 0.05). The level of IL-17 and IL-4 in the observation group decreased significantly, whereas, the level of IL-10 and IFN-γ increased considerably. Differences were all statistically significant (p < 0.05). Peripheral blood CD4+ T lymphocytes in the observation group patients expressed lower levels of nicotinic acetylcholine receptors α7 (α7nAChR) compared to the control group. Then difference was statistically significant (p < 0.05). CONCLUSIONS: Broncho-Vaxom OM-85BV reduced the onset of infant capillary bronchitis secondary bronchial asthma, relating to the reduced inflammation reaction. It also regulated the immunologic function of Th1/Th2, and lowered the α7nAChR level. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Elevated miR-181a is associated with the transition of ovarian tissues from normal into a cancerous state. However, its regulative effect on multidrug resistance (MDR) of ovarian cancer is not quite clear. Therefore, this study aimed to investigate its regulative effects on epithelial-to-mesenchymal transition (EMT) and MDR in ovarian cancer. MATERIALS AND METHODS: The expression profile of miR-181a in normal and ovarian cancer tissues was firstly quantified using qRT-PCR analysis. Then, human ovarian cancer cell line SKOV3 were transfected for miR-181a overexpression and the paclitaxel-resistant variant SKOV3/PTX cells were transfected for miR-181a knockdown. The effect of miR-181a overexpression/knockdown on EMT and PTX sensitivity were studied. RESULTS: MiR-181a level in chemoresistant (CR) cancer tissues were significantly higher than in chemosensitive (CS) cancer tissues and in normal tissue. SKOV3/PTX cells had significantly higher expression of miR-181a and N-cadherin than SKOV3 cells. SKOV3 cells had decreased E-cadherin expression and increased N-cadherin expression after enforced miR-181a expression, while SKOV3/PTX cells had increased E-cadherin expression and decreased N-cadherin expression after miR-181a knockdown. SKOV3 cells had increased P-gp expression after enforced miR-181a expression. Following MTT assay and flow cytometry analysis both confirmed that miR-181a overexpression decreased the PTX sensitivity of SKOV3 cells and while miR-181a inhibition increased the sensitivity of SKOV3/PTX cells. CONCLUSIONS: MiR-181a is an important oncomiR significantly increased in chemoresistant ovarian cancer. Its upregulation is associated with increased level of EMT and decreased cell apoptosis induced by PTX treatment. [ABSTRACT FROM AUTHOR]