Association between tobacco exposure and bladder cancer recurrence:A systematic review and meta-analysis

BACKGROUND However,the connection between smoking and the prognosis of patients with bladder cancer remains unclear.AIM To determine whether smoking is linked to the recurrence and progression of bladder cancer.METHODS As of July 20,2022,relevant English-language research was identified by searching PubMed,the Web of Science,and the Cochrane Library.We pooled the available data from the included studies using a random effects model.Subgroup analysis and sensitivity analysis were also conducted.RESULTS A total of 12 studies were included in this meta-analysis.The combined analysis revealed that tobacco exposure was associated with a significantly greater recurrence rate than nonsmoking status[odd ratios(OR)=1.76,95%CI:1.84-2.93],and the progression of bladder cancer was significantly greater in smokers than in nonsmokers(OR=1.21,95%CI:1.02-1.44).Stratified analysis further revealed that current smokers were more likely to experience relapse than never-smokers were(OR=1.85,95%CI:1.11-3.07).Former smokers also had a greater risk of relapse than did never-smokers(OR=1.73,95%CI:1.09-2.73).Subgroup analysis indicated that non-Caucasians may be more susceptible to bladder cancer recurrence than Caucasians are(OR=2.13,95%CI:1.74-2.61).CONCLUSION This meta-analysis revealed that tobacco exposure may be a significant risk factor for both the recurrence and progression of bladder cancer.

Hydrodynamic characteristics and noise reduction mechanism of a wave leading hydrofoil placed in the wake of a cylinder

We have investigated the hydrodynamic and acoustic performance of a hydrofoil with a wave leading edge that is being ingested in a cylindrical wake,to explore the interaction and noise reduction mechanism with the use of near flow field and far field noise decoupled prediction methods of large eddy simulation(LES)and Ffowcs Williams-Hawkings(FW-H).Our results indicate that the wave leading edge has minimal effect on the hydrodynamic performance,however,it has demonstrated the ability to significantly improve the acoustic performance.Through the comparison of sound pressure level(SPL)and acoustic directivity,we have observed that the wave leading edge can significantly reduce the broadband noise in the far field.This is due to its ability to break the large-scale structure of the incoming flow,which weakens the direct impact and therefore reduces the tone noise.Additionally,the interaction between the broken vortex and the boundary layer around the hydrofoil surface is weakened,leading to a reduction in surface pressure pulsation and broadband noise intensity.The wave structure primarily affects the flow structure near the leading edge,resulting in a reduction in flow disturbance and sound source intensity,and an improvement in the acoustic feedback loop between the foil and the fore-cylinder.

Research on the collapse process of a near-wall bubble

The effect of wall on the bubble collapse is significant. A compressible numerical simulation method based on the state equation was used to numerically calculate the collapse process of bubbles at different leaving wall distances. The results show that when the dimensionless distance between the bubble center and the wall is greater than zero, the bubble generates a high-pressure region at the top of the interface, which induces a jet toward the wall. When the dimensionless distance is less than zero, the jet is generated from the vicinity of the contact position between the bubble and the wall and moves along the wall towards the center axis of the bubble. When the dimensionless distance is equal to zero, that is, the center of the bubble coincides with the center of the wall, the bubble shrinks uniformly, and its collapse process is consistent with that of a single bubble in free space under the same parameter conditions. Comparison of these three typical cases of dimensionless distance from the wall reveals that the presence of the wall induces an asymmetric effect and a pressure gradient effect in the flow field around the bubble, and the farthest point away from the center of the attached wall is a high-pressure region, which induces destabilization of the bubble interface and the occurrence of jets.

Secure connectivity analysis in unmanned aerial vehicle networks

The distinctive characteristics of unmanned aerial vehicle networks （UAVNs）, including highly dynamic network topology, high mobility, and open-air wireless environments, may make UAVNs vulnerable to attacks and threats. In this study, we propose a novel trust model for UAVNs that is based on the behavior and mobility pattern of UAV nodes and the characteristics of inter-UAV channels. The proposed trust model consists of four parts： direct trust section, indirect trust section, integrated trust section, and trust update section. Based on the trust model, the concept of a secure link in UAVNs is formulated that exists only when there is both a physical link and a trust link between two UAVs. Moreover, the metrics of both the physical connectivity probability and the secure connectivity probability between two UAVs are adopted to analyze the connectivity of UAVNs. We derive accurate and analytical expressions of both the physical connectivity probability and the secure connectivity probability using stochastic geometry with or without Doppler shift. Extensive simulations show that compared with the physical connection probability with or without malicious attacks, the proposed trust model can guarantee secure communication and reliable connectivity between UAVs and enhance network performance when UAVNs face malicious attacks and other security risks.