196 research outputs found

    The Reliability Model of Artificial Monitoring on the Anomalous Event in Expressway Tunnels and Monte Carlo Simulation

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    Artificial monitoring remains to be a major way to detect anomalous events in expressway tunnels. To estimate the reliability of artificial monitoring on anomalous events in expressway tunnels, the video surveillance and mobile inspection based reliability models of artificial monitoring on the anomalous event in the expressway tunnel were built, and Monte Carlo method was applied to calculate the probability and mean time to detect the anomalous event at the specific time. The results showed that the Monte Carlo method could simulate video surveillance and mobile inspection, and obtain the probability distribution and mean time of detecting anomalous events. The mean time to spot the anomalous event was in reverse relation with the number of inspectors, the time of mobile inspection, and the reliability probability of the monitoring pre-warning system in tunnels and was in positive relationships with the departure interval. Combined with the actual operation cost, the model serves as a basis for the artificial monitoring package

    Drivers in Expressway Superlong Tunnels: The Change Patterns of Visual Features and the Discriminant Model of Driving Safety

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    A real-vehicle experiment was carried out in the superlong highway tunnel environment to study the change patterns of driver’s visual features, tracked by eye tracking devices, and the discriminant model of driver’s safety status. On the basis of statistical analysis, a single index and a comprehensive index discriminant model, both based on a C4.5 decision tree, were established. The results showed that compared with the non-tunnel highway sections, the driver’s pupil size was larger, and the gaze duration was longer in the tunnel section. Driver’s pupil size was larger in mid-tunnel section than in the entrance section and exit section. Gazes at the exit section were mainly short gazes. Compared to the exit section, driver’s pupil size changed more dramatically in the entrance section, and the gaze duration was longer. The single visual parameter indicator could clearly discriminate the driver’s safety status in the mid-tunnel section and the non-tunnel sections, while the dual-index-based identification model could clearly discriminate the safety status in each highway sections. The study deepens the research on the driver information perception model in superlong highway tunnels. Also, the study provides a theoretical basis for establishing a visual-feature-based real-time safety status discriminant

    Effects of In-vehicle Information on Driver Blink Characteristics and Workload

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    A real-vehicle experiment was carried out to study the effects of in-vehicle information on driver workload, during which data of the driver blink duration and frequency were collected to check for discrepancies among drivers with and without vehicle navigation usage. In the meanwhile, the blink characteristics of drivers with vehicle navigation device mounted at three different positions were explored through image prompt or image & sound multi-channel simultaneous prompt. Experimental results showed that when the data of blink with a duration of 0-200ms was distributed at a 10ms interval, the driver blink count distribution curve shows obvious bimodal characteristics. The peak of blink with 50-60ms duration was lower than that with 10-20ms duration when vehicle navigation was not used, and higher when vehicle navigation was used. The difference between medium and long blinks was not significant when the navigation device was mounted at different positions, yet the short blinks showed a significant difference. The peaks of blink count without voice navigation were all greater than those with voice navigation. In particular, without voice navigation, the short blinks increased obviously, and the medium blinks increased relatively, but the long blinks remained almost unchanged. The above results indicate that the driver workload was greater when using vehicle navigation. When the navigation device is installed in position B, the driver workload reaches the minimum. Using voice navigation could reduce driver workload

    Different RET Gene Mutation-Induced Multiple Endocrine Neoplasia Type 2A in 3 Chinese Families

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    BACKGROUD: Multiple endocrine neoplasia type 2A (MEN2A) is a condition with inherited autosomal dominant mutations in RET (rearranged during transfection) gene that predisposes the carrier to extremely high risk of medullary thyroid cancer (MTC) and other MEN2A-associated tumors such as parathyroid cancer and/or pheochromocytoma. Little is reported about MEN2A syndrome in the Chinese population. METHODS: All members of the 3 families along with specific probands of MEN2A were analyzed for their clinical, laboratory, and genetic characteristics. Exome sequencing was performed on the 3 probands, and specific mutation in RET was further screened on each of the family members. RESULTS: Different mutations in the RET gene were identified: C634S in Family 1, C611Y in Family 2, and C634Y in Family 3. Proband 1 mainly showed pheochromocytoma with MTC, both medullary thyroid carcinoma and pheochromocytoma were seen in proband 2, and proband 3 showed medullary thyroid carcinoma. CONCLUSION: The genetic evaluation is strongly recommended for patients with a positive family history, early onset of age, or multiple sites of masses. If the results verified the mutations of RET gene, thyroidectomy should be undertaken as the guide for better prognosis

    Metformin represses bladder cancer progression by inhibiting stem cell repopulation via COX2/PGE2/STAT3 axis

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    Cancer stem cells (CSCs) are a sub-population of tumor cells playing essential roles in initiation, differentiation, recurrence, metastasis and development of drug resistance of various cancers, including bladder cancer. Although multiple lines of evidence suggest that metformin is capable of repressing CSC repopulation in different cancers, the effect of metformin on bladder cancer CSCs remains largely unknown. Using the N-methyl-N-nitrosourea (MNU)-induced rat orthotropic bladder cancer model, we demonstrated that metformin is capable of repressing bladder cancer progression from both mild to moderate/severe dysplasia lesions and from carcinoma in situ (CIS) to invasive lesions. Metformin also can arrest bladder cancer cells in G1/S phases, which subsequently leads to apoptosis. And also metformin represses bladder cancer CSC repopulation evidenced by reducing cytokeratin 14 (CK14+) and octamer-binding transcription factor 3/4 (OCT3/4+) cells in both animal and cellular models. More importantly, we found that metformin exerts these anticancer effects by inhibiting COX2, subsequently PGE2 as well as the activation of STAT3. In conclusion, we are the first to systemically demonstrate in both animal and cell models that metformin inhibits bladder cancer progression by inhibiting stem cell repopulation through the COX2/PGE2/STAT3 axis

    Metformin Reverses Prostate Cancer Resistance to Enzalutamide by Targeting TGF-β1/STAT3 Axis-Regulated EMT.

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    Although the newly developed second-generation anti-androgen drug enzalutamide can repress prostate cancer progression significantly, it only extends the survival of prostate cancer patients by 4-6 months mainly due to the occurrence of enzalutamide resistance. Most of the previous studies on AR antagonist resistance have been focused on AR signaling. Therefore, the non-AR pathways on enzalutamide resistance remain largely unknown. By using C4-2, CWR22Rv1 and LNCaP cell lines, as well as mice bearing CWR22Rv1 xenografts treated with either enzalutamide or metformin alone or in combination, we demonstrated that metformin is capable of reversing enzalutamide resistance and restores sensitivity of CWR22Rv1 xenografts to enzalutamide. We showed that metformin alleviated resistance to enzalutamide by inhibiting EMT. Furthermore, based on the effect of metformin on the activation of STAT3 and expression of TGF-β1, we propose that metformin exerts its effects by targeting the TGF-β1/STAT3 axis. These findings suggest that combination of metformin with enzalutamide could be a more efficacious therapeutic strategy for the treatment of castration-resistant prostate cancer
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