Tunnel Exit Research Articles

Magnetic Resonance imaging evaluation of the distance to the popliteal artery in arthroscopic popliteus tendon versus posterior cruciate ligament reconstruction.

Wide acceptance of arthroscopically treating posterolateral corner injuries has not occurred. There remains a fear of neurovascular (NV) injury while arthroscopically performing these reconstructions. The study's aim is to compare on Magnetic Resonance Scans the distance of the tibial tunnel in an arthroscopic popliteus tendon reconstruction (APB) and arthroscopic posterior cruciate ligament (PCL) reconstruction (APC) to the popliteal neurosvascular bundle. MRI scans of 93 patients were evaluated. The tibial tunnel exit point of an APB and an APC reconstruction was marked. The smallest distance of the center of the exit point of these tunnels to the NV bundle was assessed. Mean variances and distances were assessed. A Welch's unpaired t-test was calculated. The difference in variances was also assessed. Mean distance to NV bundle from the tibial tunnel in an APB procedure was 15.9mm. The mean distance to the NV bundle from an APC tibial tunnel was 11.2mm. The Welch's unpaired t-test p-value was <0.0001. The p-value of the test for equality of variances was 0.0002. The distance to the NV bundle from the tibial tunnel of an APB is significantly higher than the distance to the NV bundle from the tibial tunnel of a APC. However, there is a significantly larger variance in distance to the NV bundle in an APB. Drilling a tibial tunnel during an APB should therefore not be considered more dangerous than drilling the tibial tunnel during an APC.Level 4 LOE.

Alleviating tunnel aerodynamics through hybrid suction & blowing techniques applied to train nose sections

As high-speed railway lines upgrade speeds or develop ultra-high-speed trains, traditional passive measures may struggle to address tunnel aerodynamics and passenger comfort. This study employs numerical calculations to investigate the aerodynamic mitigation of an ultra-high-speed train traveling at U = 600 km/h through a tunnel, utilizing active suction & blowing techniques in its streamlined nose sections. The simulation employs three-dimensional, compressible, unsteady Reynolds-averaged Navier-Stokes (URANS) methods, validated against full-scale experiments. The effects of slot shapes, suction directions, activation periods, and the suction & blowing velocities (SBv) are examined. Results show that the slit design, normal direction, along with continuous activation, outperforms the rectangular design, parallel direction, and partial activation in reducing pressure peaks. Notably, maximum pressure peaks on the train and tunnel surface exhibit an exponential decay pattern as SBv increases. The micro-pressure wave 20 m from the tunnel exit decreases by 28% as SBv increases from 0 to 0.27U. Additionally, maximum slipstream peaks decrease linearly with SBv, with a more pronounced decline on the near side. While drag on the head and middle cars decreases linearly with increasing SBv, the tail car experiences a quadratic increase in drag, leading to an overall reduction in total drag. Furthermore, the reduction in side force and the positive lift of the tail car enhances train safety during tunnel passage. Overall, the hybrid suction & blowing technique offer promising prospects for enhancing the aerodynamic performance of high-speed maglev trains in the future.

Mitigation of train-tunnel aerodynamics through active airflow control at front and rear noses: Impact of slit area

As railway transportation advances toward higher speeds, traditional passive measures may struggle to meet the stringent aerodynamic criteria in tunnels, necessitating the exploration of novel active flow control techniques. This study employs three-dimensional, compressible, unsteady Reynolds-averaged Navier–Stokes simulations to investigate the aerodynamic effects of the suction and blowing slit area (S) positioned on the front and rear noses of the train. The results indicate that suction and blowing activation is particularly effective in alleviating pressure on the narrower side of the tunnel. Specifically, with a 4 m2 slit, the original 4.8% pressure difference between symmetrical points on the train body is fully eliminated. The influence of suction and blowing on the positive pressures is confined to the front and rear noses where the slits are located. Notably, only suction at the front nose mitigates pressure gradients, while blowing at the rear is unrelated. The peak-to-peak pressure (ΔP) on both the train surface and tunnel wall exhibits a linear decline, with reductions of 17.4% and 16.6%, respectively, as S increases from 0 to 4 m2. Similarly, the slipstreams on both sides of the tunnel decrease linearly with increasing slit area: with u/Umax = −0.008S + 0.24 for the near side, and u/Umin = 0.014S − 0.265 for the far side. Additionally, expanding the slit area further boosts the stability and safety of the train during tunnel exit by reducing lateral forces and rolling moments, while also decreasing overall drag, thereby partially compensating for the energy input. Although the maximum lift on the head car increases with slit area, the lift on the tail car initially rises and then decreases, helping to mitigate instability upon tunnel exit. Overall, the hybrid suction and blowing technique offers promising potential for enhancing the tunnel aerodynamics in the future.

Functional similarities and differences among subunits of the nascent polypeptide-associated complex (NAC) of Saccharomyces cerevisiae.

Protein factors bind ribosomes near the tunnel exit, facilitating protein trafficking and folding. In eukaryotes, the heterodimeric nascent polypeptide-associated complex (NAC) is the most abundant-equimolar to ribosomes. Saccharomyces cerevisiae has a minor β-type subunit (Nacβ2) in addition to abundant Nacβ1, and therefore two NAC heterodimers, α/β1 and α/β12. The additional beta NAC gene arose at the time of the whole genome duplication that occurred in the S. cerevisiae lineage. Nacβ2 has been implicated in regulating the fate of messenger RNA encoding ribosomal protein Rpl4 during translation via its interaction with the Caf130 subunit of the regulatory CCR4-Not complex. We found that Nacβ2 residues just C-terminal to the globular domain are required for its interaction with Caf130 and its negative effect on the growth of cells lacking Acl4, the specialized chaperone for Rpl4. Substitution of these Nacβ2 residues at homologous positions in Nacβ1 results in a chimeric protein that interacts with Caf130 and slows the growth of ∆acl4 cells lacking Nacβ2. Furthermore, alteration of residues in the N-terminus of Nacβ2 or chimeric Nacβ1 previously shown to affect ribosome binding overcomes the growth defect of ∆acl4. Our results are consistent with a model in which Nacβ2's ribosome association per se or its precise positioning is necessary for productive recruitment of CCR4-Not via its interaction with the Caf130 subunit to drive Rpl4 messenger RNA degradation.

CFD numerical simulation of tunnel dust pollution control using a negative pressure double extraction ventilation system

To effectively control the dust pollution problem in tunneling, we studied the dust control and removal effect of a novel negative pressure double extraction ventilation system. We first investigated the spatial and temporal evolution law of wind flow and dust under single-pressure entry ventilation conditions, and found that the dust diffused to the tunnel exit within 150s. The average dust concentrations at the driver’s location, the front of the tunnel, and the back of the tunnel were 339.26, 278.39, and 232.43mg/m3, respectively, and the average dust concentration in the tunnel was 243.74mg/m3. Subsequently, based on the principle of air extraction and dust control, a negative pressure double extraction dust control system was constructed. The spatial and temporal evolution of wind flow and dust at different locations of the exhaust duct was investigated. When the exhaust duct A was 3.0m away from the floor of the roadway, CA=3.0m, and when the exhaust duct B was 4.0m away from the left wall of the roadway, CB=4.0m, the average dust concentrations at the driver’s location, the front of the tunnel, and the back of the tunnel were 45.62, 164.58, and 5.21mg/m3, respectively. Compared with single pressure-entry type ventilation, the dust prevention effect of the system improved by 86.55%, 40.88%, and 97.76%, respectively, and this installation position was determined to be the optimal position for dust removal.

Optimal angles for independent femoral tunnel drillings to prevent damage to anatomic structures in single-bundle anterior cruciate ligament reconstruction

PurposeTo determine the optimal angles for independent femoral tunnel drillings in single-bundle anterior cruciate ligament reconstruction (ACLR) in different races and genders with the aim of preventing damage to lateral femoral anatomic structures (LFAS), posterior cortex and medial femoral condyle.MethodsThis study included 180 volunteers, including 90 Caucasian and 90 matched Chinese. Magnetic resonance imaging (MRI) was used to scan the knees to create three-dimensional bone models, the ACL femoral footprint centre and the LFAS. In each femur model, femoral tunnels were established using a set of 16 distinct angular combinations: 15°, 30°, 45°, and 60° in the axial plane, as well as 15°, 30°, 45°, and 60° in the coronal plane. The minimum distance from the tunnel exit to the LFAS was evaluated, and the tunnel length, posterior cortex damage and medial femoral condyle injury were assessed.ResultsAmong the 180 patients with simulated ACL femoral tunnels, there was damage to the anatomical structure in parts of the model. According to the Cochran Q test results (P < 0.001), the percentage of safe tunnels varied significantly among the 16 different drilling angle combinations. The overall occurrence of the tunnel exit causing injury to LFAS were 8.3% and 8.1% in Chinese and Caucasian groups (P = 0.786). The means for tunnel length in Caucasians was 40.1 ± 7.9 mm, respectively; for Chinese, the results was 38.8 ± 6.6 mm (P < 0.001). Females had significantly shorter femoral tunnels than males in both Chinese and Caucasian (P < 0.001). The overall invasion rate of the posterior cortex and medial femoral condyle were 32.6% and 7.4% for Chinese; 31.0% and 7.4% for Caucasians, respectively.ConclusionTo reduce risks of injury to anatomical structures, such as the LFAS, posterior cortex and medial femoral condyle, specific angle combinations of 30°/45°, 45°/30°, 45°/45°, 45°/60°, 60°/30°, 60°/45° and 60°/60° should be used when creating the femoral tunnel in single-bundle ACLR. The selected drilling angles are critical for optimizing femoral tunnel placement.

Characterizing a device for easy simulation of compression waves induced by trains passing through tunnels

When a high-speed train enters a tunnel, an initial compression wave (ICW) is generated, which radiates out as it propagates lengthways through the tunnel to the exit, forming an uncomfortable micro-pressure wave (MPW). The aim of this research is to develop a scaled device to quickly simulate this aerodynamic phenomenon. Our device achieves this by using the instantaneous release of high-pressure air in the chamber. In the first part of the paper, the reliability of this device is verified by various methods, including an airtightness check, calibration of transducers, and repeatability experiments. Next, the mapping of the parameters of the device to engineering values is discussed. The propagation process of the ICW and the pressure fluctuations in the tunnel are then analyzed, and the discussion centers around a control variable case. Finally, the MPW generated near the tunnel exit is explored and acoustically evaluated. It is found that the initial pressure in the chamber, the opening voltage, and the number of solenoid valves in the experiment can be mapped to the train speed, the characteristic length of train nose, and the blockage ratio, respectively. When the pressure amplitude of the ICW is higher, there will be a certain steepening phenomenon in the propagation process. The pressure fluctuation cycle in the tunnel is calculated as 4× tunnel length/wave velocity, and the amplitude of fluctuation decays exponentially over the cycles. In most cases, the sound pressure level of MPWs near the tunnel exit exceeds the hearing threshold, based on the auditory properties of the human ear.

Anatomical Significance of the Patent Foramen Ovale by Real-Time 3D TEE in Cryptogenic Stroke and Migraine.

The transesophageal echocardiogram (TEE) is the standard imaging modality for confirming the presence or absence of patent foramen ovale. PFO is a flap valve depending on the pressure change between the left and right atrium, which can help determine whether to open. 3D-TEE was shown to optimize the visualization of PFO. There is a causal association between PFO and unexplained stroke. It seems that 3D-TEE can present a high-risk PFO morphological feature, which seems to show more than just being easier to open. In total, 134 consecutive patients with cryptogenic stroke or migraine who had suspected PFO and underwent c-TCD, TTE, and c-TEE were included in this study. TEE confirmed the PFO. The right-to-left shunt (RLS) grade of PFO at rest and abdominal compression Valsalva maneuver was detected by c-TEE. The long diameter of FO (1.74 ± 0.3vs. 1.60 ± 0.4, p = 0.039), the short diameter of FO (1.12 ± 0.3vs. 1.00 ± 0.3, p = 0.036), perimeter of FO (4.62 ± 0.7vs. 4.22 ± 1.0, p = 0.026), and area (1.80 ± 0.8vs. 1.35 ± 0.8, p = 0.05) of the FO were significantly larger in the larger RLS group. In group of CS, a larger proportion of Eustachian valve or a Chiari's network (14.3%vs. 3.5%, p = 0.036), a larger proportion of in the left funnelform (55.1%vs. 16.3%, p < 0.001), a longer length of the PFO tunnel (13.4 ± 4.4vs. 7.8 ± 2.5, p < 0.001), a lower IVC-PFO angle (16.4 ± 3.4vs. 20.3 ± 7.7, p = 0.001), a higher proportion of LA multiple exits of the tunnel (46.9%vs. 14.3%, p < 0.001). Multivariate regression analysis showed that male gender (HR: 4.026, 95% CI: 0.883-18.361, p = 0.072), age (HR: 1.076, 95% CI: 1.002-1.155, p = 0.045), the left funnelform (HR: 7.299, 95% CI: 1.585-33.618, p = 0.011), a longer length of the PFO tunnel (HR: 1.843, 95% CI: 1.404-2.418, p < 0.001) and multiple exits of the tunnel of LA (HR: 8.544, 95% CI: 1.595-45.754, p = 0.012) increased the risk of cerebral infarction. The cut-off value calculated by ROC for the diagnosis of high-risk PFO was that the length of the PFO tunnel was 12mm and the left funnelform combined with multiple exits of the left atrial (sensitivity was 92%, specificity was 90%). The area under the curve of the combined index versus PoPE score (0.932 vs. 0.736) relative to the RoPE score was statistically significant. TEE has shown outstanding advantages in displaying the specific morphological characteristics of PFO. The left funnelform, a longer length of the PFO tunnel, and multiple exits of the tunnel of LA are associated with an increasing risk of CS in anatomical PFO respect.

Observation of Attosecond Time Delays in Above-Threshold Ionization.

Attosecond-scale temporal characterization of photoionization is essential in understanding how light and matter interact on the most fundamental level. However, characterizing the temporal property of strong-field above-threshold ionization has remained unreached. Here, we propose a novel photoelectron interferometric method to disentangle the contribution of Coulomb effect from an attoclock, allowing us to clock energy-resolved time delays of strong-field above-threshold ionization. We disentangle two types of Coulomb effects for the attoclock, i.e., one arising from the Coulomb disturbance of a single electron trajectory and the second effect arising from the photoelectron phase space distortion due to the Coulomb field. We find that the second Coulomb effect manifests itself as an energy-resolved attosecond time delay in the electron emission, which is relevant to the effect of nonadiabatic initial longitudinal momentum at the tunnel exit. Our study further indicates a sensitivity of the time delay to the temporal profile of the released electron wave packet within one half laser cycle. The temporal width of the released electron wave packet is found to increase with energy, which contradicts the common assumption in the adiabatic picture.

Ribosome-inactivation by a class of widely distributed C-tail anchored membrane proteins

Ribosome hibernation is a commonly used strategy that protects ribosomes under unfavorable conditions and regulates developmental processes. Multiple ribosome-hibernation factors have been identified in all domains of life, but due to their structural diversity and the lack of a common inactivation mechanism, it is currently unknown how many different hibernation factors exist. Here, we show that the YqjD/ElaB/YgaM paralogs, initially discovered as membrane-bound ribosome binding proteins in E.coli, constitute an abundant class of ribosome-hibernating proteins, which are conserved across all proteobacteria and some other bacterial phyla. Our data demonstrate that they inhibit invitro protein synthesis by interacting with the 50S ribosomal subunit. Invivo cross-linking combined with mass spectrometry revealed their specific interactions with proteins surrounding the ribosomal tunnel exit and even their penetration into the ribosomal tunnel. Thus, YqjD/ElaB/YgaM inhibit translation by blocking the ribosomal tunnel and thus mimic the activity of antimicrobial peptides and macrolide antibiotics.

Slope Failure Treatment by Anchor Rod Method at Exit of Tunnel: Case Study in Nanxia Expressway

Slope Failure Treatment by Anchor Rod Method at Exit of Tunnel: Case Study in Nanxia Expressway

Study on the Settlement and Deformation Characteristics of Surrounding Rock of Loess Tunnel

There is a water culvert with masonry structure in the mountain of Hanguguan Tunnel. Soil deformation caused by tunnel excavation leads to channel cracking. On the one hand, channel water infiltration leads to loess tunnel collapse, which can easily cause engineering accidents and delay the construction period. On the other hand, it will affect the channel water supply and cause social problems. In this paper, the spatial deformation of the tunnel excavation process in the loess layer is revealed through the settlement of the vault in the tunnel, the monitoring of the convergence of the perimeter, and the force monitoring of the lining support structure of the Hanguguan tunnel, and the influence of the tunnel excavation deformation on the culvert is revealed through numerical calculation. The results show that the arch at the tunnel exit has the largest settlement deformation, the larger cumulative settlement, and the faster settlement rate, and the deformation of the culvert is small, only a millimeter. Compared with the monitoring data, the numerical simulation of tunnel excavation and the vertical settlement are basically consistent with the actual situation.

Radiographic acceptable zone of endobutton placement in ACL reconstruction: A prospective study.

During the transportal technique of anterior cruciate ligament (ACL) reconstruction, tunnel outlet location can be varied depending on certain anatomical and technical characteristics. Therefore, we aimed to find out the acceptable zone of endobutton location by introducing several radiographic values. Postoperative lateral radiographs of 72 patients were assessed to measure the distances from the centre of the button to the posterior femoral cortex (D1) and to the most distal point of the lateral condyle (D2). Furthermore, based on the anteroposterior (AP) radiographs, the distances from the centre of the button to the lateral femoral cortex (D3) and from the centre of the button to the line connecting the most distal points of the medial and lateral femoral condyles (D4) were assessed. To measure the sensitivity and specificity of each radiographic value (D1, D2, D3 and D4), the area under the receiver operating characteristic curve was calculated. The alpha angle and femoral tunnel length values were considered as gold standards. Analyses showed that the mean values for D1, D2, D3 and D4 were 13.20 ± 0.54, 39.44 ± 0.31, 1.65 ± 0.15 and 42.66 ± 0.47 mm, respectively. The mean angle was found to be 38.6 ± 0.3°, and the mean femoral tunnel length was 38.6 ± 0.2 mm. Age was significantly related to D2 and the diameter of the femur in AP X-ray, while body mass index had a significant relation with D3 (p < 0.05). In this study, a new method was proposed to evaluate the accuracy of anatomical tunnel placement in ACL reconstruction surgery postoperatively. The statistical analysis of the measured variables showed that the mean ratios were 21.79 ± 0.87 for D1, 65.65 ± 0.63 for D2 and 51.90 ± 0.73 for D4. The results indicated that if the tunnel exit location and endobutton placement in the postoperative radiological images fall within the suggested areas, it can be meaningfully concluded that the tunnel is correctly positioned intraarticularly and the ligament reconstruction is anatomical. Level III.

Supporting driver performance in closely spaced tunnel-interchange structure: Traffic control devices and effects on driving behavior

Objectives With the rapid development of expressways in the mountainous regions of southwestern China, closely spaced tunnel-interchange structures have inevitably emerged due to topographical constraints and environmental limitations. Given the unfavorable road geometry and rapid cross-section transitions, drivers face significant safety concerns. This study aims to investigate drivers’ safety performance at closely spaced tunnel-interchange sections and determine how safety risks can be mitigated through improved traffic control devices design. Methods Thirty-nine participants conducted an experimental study in a fixed-base simulator. The test scenario was modeled on the Xingyan Freeway-S3801 and accurately reproduced in the simulator. For each safety performance metric, the driving simulator experiments yielded a dataset with 780 observations. To address the idiosyncratic variation due to individual driver differences, a series of linear mixed effects models (LMM) were developed to analyze drivers’ behavior responses. Results In closely spaced tunnel-interchange sections, a general impairment of both longitudinal and lateral performance was observed. This study identified potential critical impact variables in traffic control device systems. According to the LMM results: (a) Removing the 0.5 km interchange ramp exit advance guide sign located in the tunnel exit area reduces dangerous behavior in the corresponding impact area. (b) Replacing the 0.5 km interchange ramp exit advance guide sign with arrow pavement markers as an information source supports improved driver performance, promoting driver safety. (c) Adding tunnel exit distance signs within tunnels is recommended to enhance situation awareness for drivers. Conclusions This study addresses the scientific issues related to traffic control devices setup for closely spaced tunnel-interchange sections, focusing on identifying potential critical impact variables. The findings provide guidance on the design of traffic control devices for such sections and support revisions to national engineering standards.

Multi-protein assemblies orchestrate co-translational enzymatic processing on the human ribosome

Nascent chains undergo co-translational enzymatic processing as soon as their N-terminus becomes accessible at the ribosomal polypeptide tunnel exit (PTE). In eukaryotes, N-terminal methionine excision (NME) by Methionine Aminopeptidases (MAP1 and MAP2), and N-terminal acetylation (NTA) by N-Acetyl-Transferase A (NatA), is the most common combination of subsequent modifications carried out on the 80S ribosome. How these enzymatic processes are coordinated in the context of a rapidly translating ribosome has remained elusive. Here, we report two cryo-EM structures of multi-enzyme complexes assembled on vacant human 80S ribosomes, indicating two routes for NME-NTA. Both assemblies form on the 80S independent of nascent chain substrates. Irrespective of the route, NatA occupies a non-intrusive ‘distal’ binding site on the ribosome which does not interfere with MAP1 or MAP2 binding nor with most other ribosome-associated factors (RAFs). NatA can partake in a coordinated, dynamic assembly with MAP1 through the hydra-like chaperoning function of the abundant Nascent Polypeptide-Associated Complex (NAC). In contrast to MAP1, MAP2 completely covers the PTE and is thus incompatible with NAC and MAP1 recruitment. Together, our data provide the structural framework for the coordinated orchestration of NME and NTA in protein biogenesis.

Numerical studies on the radiation of micro-pressure wave noise at the tunnel exits

To effectively control the micro-pressure wave noise radiating from tunnel exits, numerical simulations were conducted to investigate the generation and propagation of such noise at the exits of high-speed metro tunnels. Large-eddy simulation was employed to obtain the near-field unsteady flow field data at the tunnel exit. The Ffowcs Williams–Hawkings (FW–H) acoustic analogy was used to predict the types of sound sources for micro-pressure wave noise. The unsteady flow field data were also utilized for finite element method acoustic analysis to calculate the far-field radiation of micro-pressure wave noise. The accuracy of the numerical methods was verified through moving model tests. The results indicate that dipole noise dominates within the micro-pressure wave noise. The tunnel's inner wall contributes most to the dipole sound sources. Dipole noise radiates outward in the form of semi-ellipsoidal waves, with energy mainly concentrated below 20 Hz and a peak frequency of 4 Hz. Furthermore, the decay of dipole noise in the direction of the tunnel exit follows a similar exponential decay pattern to that of an explosion shock wave. When the train speed exceeds 400 km/h, the human ear can distinctly perceive the sonic booms at the tunnel exit.

Numerical Analysis of Flood Invasion Path and Mass Flow Rate in Subway Stations under Heavy Rainfall Conditions

The occurrence of extreme weather, such as heavy rainfall and sudden increases in precipitation, has led to a notable rise in the frequency of flooding in subway stations. By conducting numerical simulations of flood disasters in subway stations under heavy rainfall conditions and gaining insights into the patterns of flood invasion inside the stations, it is possible to develop practical and feasible drainage designs for the stations. This paper employs the computational fluid dynamics (CFD) method, utilising the volume of fluid function (VOF) method and the renormalization k-ε group model within the vortex viscosity model. The complete process of flood invasion into subway stations with varying water levels (1500 mm, 2000 mm, and 2450 mm) is modelled, and the distribution of floods at different times under varying operational conditions is analysed to identify the evolutionary patterns of station flood history. The simulation calculations yielded the mass flow rate time history curve at the tunnel entrance and exit, which was then subjected to an analysis of its development trend over time. The total accumulated water in the subway station is calculated by integrating the difference in mass flow rate between the entrance and the tunnel exit, using the mass flow rate curve. In conclusion, the paper proposes drainage measures that provide valuable insights into pumping strategies when floodwaters infiltrate subway stations. The results indicate that the speed of flood spreading in subway stations increases with higher groundwater levels, and that the mass flow rate of floodwater entering the tunnels increases over time, eventually reaching a stable state. It was observed that, at certain times, the mass flow rate of floodwater into the tunnels exhibited a linear relationship with time.

Exploring the causes of frequent accidents at highway tunnel exits: Coupling analysis of the slack effect and white hole effect in extra-long tunnels

In this paper, the causes of frequent traffic accidents at the exits of highway tunnels are investigated. This study recruited 34 subjects to conduct vehicle experiments using an illumination meter, eye tracker, Smarter Eye and OBD to measure the illumination, eye movement characteristics, driving trajectory, and speed while driving in a tunnel exit. A questionnaire was used to investigate drivers’ subjective feelings while driving. The change trend of each indicator in the area near the tunnel exit was analyzed, and the relationships among the light environment, driver physiology, driving behavior, and driver psychology were explored. The psychological and physiological inconsistency phenomenon and abnormal acceleration behavior were observed at the tunnel exit, and the slack effect was verified. As the tunnel exit area is driven through, with the rapid increase in illumination, the rate of change of the driver’s pupil area increases, and the distance between the vehicle and the tunnel sidewall increases. It is unreasonable that in a tunnel exit with a poor traffic environment, some drivers experience psychological slack and tend to increase their speed and accelerate out of the tunnel. The slack effect is observed in most drivers, approximately 79.4% of the total. The white hole effect interferes with drivers’ vision and reduces their ability to obtain traffic information. The slack effect reduces drivers’ attention and increases vehicle speed. A coupling effect exists between the white hole and slack effects, which together threaten traffic safety at the tunnel exit.

Robot-assisted transosseous repair of triangular fibrocartilage complex: a cadaver study.

The feasibility and accuracy of robot-assisted bone tunnel construction in the transosseous repair of the triangular fibrocartilaginous complex (TFCC) were compared with those of freehand arthroscopic repair. A total of 20 cadaveric specimens were randomized into robotic-assisted and arthroscopy-guided groups. Three bone tunnels were constructed in the ulnar foveal region in each specimen. The discrepancy between the planned and actual tunnel exits was determined in the robot-assisted group by merging images. The success rate of tunnel construction, time consumption and number of drilling attempts were compared between groups. The median planned/actual exit discrepancy was 0.8 mm in the robot-assisted group, with 90% of tunnel exits successfully placed in the footprint region, compared to 63.3% in the arthroscopy-guided group. The robot-assisted group spent less time and required fewer drilling attempts to construct bone tunnels. These results indicated that the robot-assisted technique can accurately construct multiple bone tunnels in the foveal region and reduce the difficulty of TFCC transosseous repair.Level of evidence: III.

Influence of an adjacent tunnel connecting zone shading shed on drivers’ eye movement characteristics

A tunnel shading shed is crucial in improving driving safety as a type of traffic facility to ease the transition of light environments. To study the effect of installation of a shading shed on the visual characteristics of drivers in the connecting zone of the adjacent tunnels, a total of 32 drivers were gathered to perform a real vehicle experiment. The study zone of the adjacent tunnels was divided into three sections: upstream tunnel exit; connecting zone; and downstream tunnel threshold zone. Fixation duration, saccade duration and saccade frequency were selected as research indexes. The results suggest that installation of a shading shed in the connecting zone significantly reduced the fixation (saccade) duration in the upstream tunnel exit and downstream tunnel threshold zones, with a significantly higher saccade frequency. In addition, fixation is better improved at the downstream tunnel entrance, and saccade is better enhanced at the upstream tunnel exit.