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With the continuous improvement requirements of reliability and security for mechanical equipment,accurate extraction of equipment fault development trend of degradation characteristic information and establishment of effective fault prediction model is the key problem to improve reliability of equipment operation. HMM has double random process properties that could describe the hidden state and observed state,it is similar to the equipment degradation processes that become a hot research topic now. On various methods based on the fault identification and diagnosis technology, the equipment fault prognostics methods based on hidden Markov model and hidden semi-Markov model are summarized, advantages and disadvantages of each method are analyst and compared. Finally,its development trend on equipment degradation assessment and prognostics is pointed out.

A synchronous control system of virtual main-axis based on extended sliding mode disturbance observer is designed to solve some problems that coupling of multi-axis synchronous control of electronic gears is low and has poor anti-interference ability, and a large amount of synchronization error callback overshoot in bag-making machines. First, a velocity compensator is designed in order to establish the coupling relationship between the virtual and traction motor. Second, a nonsingular terminal sliding mode controller and a disturbance observer are used to enhance the anti-disturbance capability of the system. Finally, by using MATLAB/Simulink simulation, the viability and superiority of the method in multi-axis synchronous control are proved. The simulation results demonstrate that the control method decreases the synchronization error and the callback overshoot between the traction motors, and enhances the coupling performance and anti-interference ability of the system, which has a more significant impact on the high-performance synchronization control for the multi-traction motor system of the bag-making machine. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) play important roles in regulation of gene expressions and likely have involvement in cancer susceptibility and disease progression. MicroRNA-101 (miR-101) has been well established as a tumor suppressor, and aberrant expression of miR-101 levels has been previously reported in different malignancies including head and neck squamous cell carcinoma (HNSCC). However, the role of single nucleotide polymorphisms (SNPs) of miR-101 in the susceptibility to HNSCC remains unclear. In this study, we genotyped 11 selected SNPs of the miR-101 genes (including miR-101-1 and miR-101-2) in a case-control study including 576 HNSCC cases and 1552 cancer-free controls. For the main effect analysis, none of the 11 selected SNPs was associated with HNSCC risk. However, in the stratification analysis by tumor sites, rs578481 and rs705509 in pri-miR-101-1 were significantly associated with risk of oral squamous cell carcinoma (OSCC) (rs578481: adjusted odds ratio (OR) = 1.19, 95 % confidence interval (CI) 1.01-1.39, P = 0.036; rs705509: adjusted OR = 0.85, 95 % CI 0.73-0.98, P = 0.030). Furthermore, combined analysis of the two SNPs revealed that subjects carrying the risk alleles of rs578481 and rs705509 had increased risk of OSCC in a dose-response manner ( P = 0.022). Compared with subjects carrying '0-2' risk alleles, subjects carrying '3-4' risk alleles presented a 1.38-fold increased risk of OSCC. In conclusion, our findings suggested that the SNPs rs578481 and rs705509 locating in pri-miR-101-1 may play a role in genetic susceptibility to OSCC, which may improve our understanding of the potential contribution of miRNA SNPs to cancer pathogenesis. [ABSTRACT FROM AUTHOR]

Backgrounds: The activation of Toll-like receptors (TLRs) may be an important event in the immune evasion of tumor cell. Recently, numerous studies have investigated the associations between TLR2 −196 to −174 del and two SNPs of TLR4 (rs4986790 and rs4986791) and the susceptibility to different types of cancer; however, the results remain conflicting. The aim of this study was to assess the association between TLR2 and TLR4 polymorphisms and cancer risk in a meta-analysis with eligible published studies. Methodology/Principle Findings: A dataset composed of 14627 cases and 17438 controls from 34 publications were included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and three SNPs of TLRs (TLR2 −196 to −174 del, TLR4 rs4986790 and rs4986791). The results showed that all of these three polymorphisms were significantly associated with the increased cancer risk (dominant model: OR = 1.64, 95% CI: 1.04–2.60 for TLR2 −196 to −174 del; OR = 1.19, 95% CI: 1.01–1.41 for TLR4 rs4986790; and OR = 1.47, 95% CI: 1.120–1.80 for TLR4 rs4986791; respectively). In stratified analysis, we found the effect of TLR2 −196 to −174 del on cancer risk remained significant in the subgroup of Caucasians and South Asians, but not in East Asians. However, the association between rs4986791 and cancer risk was significant in both South Asians and East Asians, but not in Caucasians. Furthermore, the association between rs4986790 and cancer risk was statistically significant in digestive cancers (dominant model: OR = 1.76, 95% CI: 1.13–2.73) and female-specific cancers (dominant model: OR = 1.50, 95% CI: 1.16–1.94). However, no significant association with risk of digestive system cancers was observed for TLR2 −196 to −174 del and TLR4 rs4986791. Conclusions/Significance: This meta-analysis presented additional evidence for the association between TLR2 and TLR4 polymorphisms and cancer risk. Further well-designed investigations with large sample sizes are required to confirm this conclusion. [ABSTRACT FROM AUTHOR]

As the most efficient perception system in nature, the perception mechanism of the insect (such as honeybee) antennae is the key to imitating the high-performance sensor technology. An automated experimental device suitable for collecting electrical signals (including antenna reaction time information) of antennae was developed, in response to the problems of the non-standardized experimental process, interference of manual operation, and low efficiency in the study of antenna perception mechanism. Firstly, aiming at the automatic identification and location of insect heads in experiments, the image templates of insect head contour features were established. Insect heads were template-matched based on the Hausdorff method. Then, for the angle deviation of the insect heads relative to the standard detection position, a method that calculates the angle of the insect head mid-axis based on the minimum external rectangle of the long axis was proposed. Eventually, the electrical signals generated by the antennae in contact with the reagents were collected by the electrical signal acquisition device. Honeybees were used as the research object in this study. The experimental results showed that the accuracy of template matching could reach 95.3% to locate the bee head quickly, and the deviation angle of the bee head was less than 1°. The distance between antennae and experimental reagents could meet the requirements of antennae perception experiments. The parameters, such as the contact reaction time of honeybee antennae to sucrose solution, were consistent with the results of the manual experiment. The system collects effectively antenna contact signals in an undisturbed state and realizes the standardization of experiments on antenna perception mechanisms, which provides an experimental method and device for studying and analyzing the reaction time of the antenna involved in biological antenna perception mechanisms.

MicroRNAs (miRNAs) play important roles in regulation of gene expressions and likely have involvement in cancer susceptibility and disease progression. MicroRNA-101 (miR-101) has been well established as a tumor suppressor, and aberrant expression of miR-101 levels has been previously reported in different malignancies including head and neck squamous cell carcinoma (HNSCC). However, the role of single nucleotide polymorphisms (SNPs) of miR-101 in the susceptibility to HNSCC remains unclear. In this study, we genotyped 11 selected SNPs of the miR-101 genes (including miR-101-1 and miR-101-2) in a case-control study including 576 HNSCC cases and 1552 cancer-free controls. For the main effect analysis, none of the 11 selected SNPs was associated with HNSCC risk. However, in the stratification analysis by tumor sites, rs578481 and rs705509 in pri-miR-101-1 were significantly associated with risk of oral squamous cell carcinoma (OSCC) (rs578481: adjusted odds ratio (OR) = 1.19, 95 % confidence interval (CI) 1.01-1.39, P = 0.036; rs705509: adjusted OR = 0.85, 95 % CI 0.73-0.98, P = 0.030). Furthermore, combined analysis of the two SNPs revealed that subjects carrying the risk alleles of rs578481 and rs705509 had increased risk of OSCC in a dose-response manner (P trend = 0.022). Compared with subjects carrying "0-2" risk alleles, subjects carrying "3-4" risk alleles presented a 1.38-fold increased risk of OSCC. In conclusion, our findings suggested that the SNPs rs578481 and rs705509 locating in pri-miR-101-1 may play a role in genetic susceptibility to OSCC, which may improve our understanding of the potential contribution of miRNA SNPs to cancer pathogenesis.

Objective: To investigate the mandibular incisive canal (MIC) with cone-beam computed tomography (CBCT)., Methods: Fifty adults were selected and CBCT was taken. The CBCT data were reconstructed to evaluate the visibility, shape, diameter, length of the MIC and its relationship with mandible., Results: MIC could be identified in 100% (100/100) of CBCT with good clarity in 71% (71/100). The diameters (horizontal diameter versus vertical diameter) of MIC became smaller from origin to end (left origin of MIC was 2.17 mm×2.22 mm, left end was 0.82 mm×0.92 mm; right origin of MIC was 2.14 mm×2.08 mm, right end was 0.87 mm×0.86 mm). The left and right mean length of MIC was 17.84 mm and 17.73 mm respectively. In bucca-lingual direction, MIC was close to buccal cortical border, and in vertical direction, MIC was close to lower margin of mandible. The distance from MIC to apex of root was shortest in canine., Conclusions: CBCT can identify MIC with high visibility and prominent clarity. In the interforaminal region of mandible, MIC was close to buccal and lower margin of mandible.