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Objective: Intermittent hypoxia, a significant feature of obstructive sleep apnea, has pro-tumorigenic effects. Here, we investigated the effect of sodium tanshinone IIA sulfonate on oxidative stress and apoptosis in a mouse model of Lewis lung carcinoma with intermittent hypoxia. Methods: Mice were randomly assigned to normoxia (control), normoxia plus sodium tanshinone IIA sulfonate (control + sodium tanshinone IIA sulfonate), intermittent hypoxia, and intermittent hypoxia + sodium tanshinone IIA sulfonate groups. Intermittent hypoxia administration lasted 5 weeks in the intermittent hypoxia groups. Lewis lung carcinoma cells were injected into the right flank of each mouse after 1 week of intermittent hypoxia exposure. Sodium tanshinone IIA sulfonate was injected intraperitoneally in the control + sodium tanshinone IIA sulfonate and intermittent hypoxia + sodium tanshinone IIA sulfonate groups. Tumor oxidative stress was evaluated by detection of malondialdehyde and superoxide dismutase. The apoptosis of tumor cells was evaluated by the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay as well as by Western blot analysis of B-cell lymphoma 2-associated X protein and cleaved caspase-3 expression. Additionally, the expression of hypoxia-induced factor-1α, nuclear factor erythroid 2-related factor 2, and nuclear factor kappa B was also evaluated by Western blot. Results: Compared with the control group, the intermittent hypoxia treatment significantly increased Lewis lung carcinoma tumor growth and oxidative stress (serum malondialdehyde) but decreased serum levels of SOD and pro-apoptotic markers (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, B-cell lymphoma 2-associated X protein, and cleaved caspase-3). These changes were significantly attenuated by intraperitoneal injection of sodium tanshinone IIA sulfonate. Lower nuclear factor erythroid 2-related factor 2 and higher nuclear factor kappa B levels in the intermittent hypoxia group were clearly reversed by sodium tanshinone IIA sulfonate treatment. In addition, sodium tanshinone IIA sulfonate administration decreased the high expression of hypoxia-induced factor-1α induced by intermittent hypoxia. Conclusion: Intermittent hypoxia treatment resulted in high oxidative stress and low apoptosis in Lewis lung carcinoma–implanted mice, which could be attenuated by sodium tanshinone IIA sulfonate administration possibly through a mechanism mediated by the nuclear factor erythroid 2-related factor 2/nuclear factor kappa B signaling pathway.

Data offloading through vehicular ad hoc networks (VANETs) is one of the most promising methods for overcoming the overload problem in cellular networks. As data delivery by service providers consumes resources such as bandwidth, storage and power, the incentive scheme with the optimal pricing strategy must be identified. In the literature, most incentive schemes focus on offloading through fixed nodes, such as roadside units (RSUs). It remains very challenging to motivate a moving vehicle to help other users deliver their data due to the high mobility of vehicles. Game theory is a widely adopted method for analyzing pricing issues in wireless networks. Therefore, this paper proposes an optimal pricing strategy that uses the Stackelberg game to model the interaction between a service provider and a service requester. Then, the Stackelberg equilibrium is derived under the corresponding conditions. Next, an algorithm is proposed for selecting the service provider that offers the lowest price based on the results of the Stackelberg equilibrium. Finally, the simulation results demonstrate that the proposed algorithm can effectively reduce the downloading time of a task while maximizing the utilities of both the service provider and the requester.

Objective. While D-dimer can successfully diagnose venous thrombosis due to its excellent negative predictive value (NPV), it cannot be used to detect venous thromboembolism (VTE) because of its low positive predictive value (PPV). This study aims to investigate if a combination of using D-dimer and fibrinogen can improve PPV in the VTE diagnosis. Methods. We retrospectively analyzed various data including D-dimer, fibrinogen, C-reactive protein, ultrasound, and others collected from 10775 traumatic fracture patients and categorized them into two groups of VTE and non-VTE. By comparing the difference between the two groups, we employ multiple logistic regression to find risk factors that are useful to detect VTE. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic yield of using fibrinogen, D-dimer, and their combination, respectively. Also, these data were classified into quartiles by patient age. We perform the same analysis on the quartiles and find if the patient’s age has an impact on diagnosing VTE. Results. The univariate analysis demonstrated that five factors of age, D-dimer, fibrinogen, C-reactive protein, and high-density lipoprotein cholesterol were significant to predict VTE. ROC showed that D-dimer was more useful than fibrinogen for the diagnosis of VTE, while the area under the curve (AUC) was 0.7296 for D-dimer and 0.5209 for fibrinogen. The cutoff point of D-dimer and fibrinogen was 424.89 ng/ml and 3.543 g/L, respectively. The specificity of fibrinogen was 0.777 which was better than D-dimer, while the sensitivity of fibrinogen was lower than that of D-dimer. Both PPV and NPV were similar in D-dimer and fibrinogen. The PPV of combining D-dimer and fibrinogen in ages Q3 (60 70) was better than using either D-dimer or fibrinogen. Conclusions. Fibrinogen is a promising strategy for the diagnosis of subclinical VTE and postoperative VTE. In particular, a combination of D-dimer and fibrinogen can improve the PPV to successfully diagnose VTE in traumatic fracture patients who are more than 60 years old. Levels of Evidence. This assay is a diagnostic test at level II.

Endoscopic video sequences provide surgeons with direct surgical field or visualisation on anatomical targets in the patient during robotic surgery. Unfortunately, these video images are unavoidably hazy or foggy to prevent surgeons from clear surgical vision due to typical surgical operations such as ablation and cauterisation during surgery. This Letter aims at removing fog or smoke on endoscopic video sequences to enhance and maintain a direct and clear visualisation of the operating field during robotic surgery. The authors propose a new luminance blending framework that integrates contrast enhancement with visibility restoration for foggy endoscopic video processing. The proposed method was validated on clinical endoscopic videos that were collected from robotic surgery. The experimental results demonstrate that their method provides a promising means to effectively remove fog or smoke on endoscopic video images. In particular, the visual quality of defogged endoscopic images was improved from 0.5088 to 0.6475.

In vehicular ad hoc networks (VANETs), safety applications require a reliable and delay-guaranteed broadcasting service to disseminate safety messages. However, channel fading and the high mobility of vehicles make it very challenging for a broadcasting scheme to meet the strict service demands of safety messages. On the other hand, cooperative retransmission is effective in mitigating wireless channel impairments by utilizing the broadcast nature of wireless channels. Therefore, this paper proposes a repetition-based cooperative broadcasting (RBCB) scheme for safety messages in VANETs. The proposed scheme enables the selected helper vehicles to perform the cooperative rebroadcasting along with the source vehicle during the source vehicle’s slot in order to increase the transmission reliability of safety messages and reduce rebroadcasting times. The performance of RBCB scheme is mathematically analyzed in terms of packet delivery probability and average packet delay under the Rayleigh fading channel. Moreover, extensive simulations are conducted to evaluate the performance of RBCB scheme. Both mathematical analysis and simulation results demonstrate that RBCB scheme significantly improves the packet delivery probability and decreases the average packet delay.

Bronchoscope three-dimensional motion estimation plays a key role in developing bronchoscopic navigation systems. Currently external tracking devices, particularly electromagnetic trackers with electromagnetic sensors, are increasingly introduced to navigate surgical tools in pre-clinical images. An unavoidable problem, which is to align the electromagnetic tracker to pre-clinical images, must be solved before navigation. This paper proposes a multiple sensor-driven registration method to establish this alignment without using any anatomical fiducials. Although current fiducially free registration methods work well, they limit to the initialization of optimization and manipulating the bronchoscope along the bronchial centerlines, which could be failed easily during clinical interventions. To address these limitations, we utilize measurements of multiple electromagnetic sensors to calculate bronchoscope geometric center positions that are usually closer to the bronchial centerlines than the sensor itself measured positions. We validated our method on a bronchial phantom. The experimental results demonstrate that our idea of using multiple sensors to determine bronchoscope geometric center positions for fiducial-free registration was very effective. Compared to currently available methods in bronchoscope three-dimensional motion estimation, our method reduced fiducial alignment error from at least 6.79 to 4.68-5.26mm and significantly improved motion estimation or tracking accuracy from at least 5.42 to 3.78-4.53mm. [ABSTRACT FROM AUTHOR]

Electromagnetically navigated endoscopy, which is increasingly applied in endoscopic interventions, utilizes an electromagnetic sensor attached at the endoscope tip to measure the endoscope movements and to navigate the endoscope in the region of interest in the body. Due to patient motion and magnetic field distortion, sensor electromagnetic tracking (EMT) measurement inaccuracy and dynamic jitter errors remain challenging for electromagnetic navigation. This paper proposes a new tracking framework of an animated particle filter that integrates adaptive particle swarm optimization into a generic particle filter to significantly boost electromagnetic trackers. We validate our method on a dynamic phantom and compare it to state-of-the-art EMT methods. Our experimental results demonstrate the effectiveness and robustness of our method, which provides position and orientation accuracy of 2.48 mm, 4.69° that significantly outperformed previous methods at least with tracking error of 4.19 mm, 7.75°. The tracking smoothness was improved from 4.09 mm, 3.37° to 1.84 mm, 2.52°. Our method successfully tackled the particle impoverishment better than standard particle filters.