Time correlation of success recanalization for endovascular recanalization of medically refractory non-acute intracranial arterial occlusions

Background and purposeThe management of patients with symptomatic non-acute atherosclerotic intracranial artery occlusion (sNAA-ICAO), which is a special subset with high morbidity and a high probability of recurrent serious ischemic events despite standard medical therapy, has been clinically challenging. A number of small-sample clinical studies have discussed endovascular recanalization for sNAA-ICAO and the lack of a uniform standard of operation time. The purpose of this study was to investigate the time correlation of successful recanalization.MethodsFrom January 2013 to August 2021, 69 consecutive patients who underwent endovascular recanalization for sNAA-ICAO were analyzed retrospectively in the First Affiliated Hospital of Harbin Medical University. The technical success rate, periprocedural complications, and rate of TIA/ischemic stroke during follow-up were evaluated.ResultsThe overall technical success rate was 73.91% (51/69), and the rate of perioperative complications was 37.68% (26/69). The percentage of patients with perioperative symptoms was 27.53% (19/69). The rate of serious symptomatic perioperative complications was 8.70% (6/69). After adjusting for age, sex, and BMI, the effect of the time from the last symptom to operation on successful recanalization was 0.42 (IQR, 0.20, 0.88, P = 0.021), before the inflection point (51 days).ConclusionsEndovascular recanalization for sNAA-ICAO is technically feasible in reasonably selected patients. The perioperative safety is within the acceptable range. Before 51 days, the last symptoms to operation time, for every 10 days of delay, the probability of successful recanalization is reduced by 57%

Mesenchymal stem cells as carriers and amplifiers in CRAd delivery to tumors

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern, kinetic delivery of adenovirus, and therapeutic efficacy of the MSC loading of E1A mutant conditionally replicative adenovirus Adv-Stat3(-) which selectively replicated and expressed high levels of anti-sense Stat3 complementary DNA in breast cancer and melanoma cells.</p> <p>Methods</p> <p>We assessed the release ability of conditionally replicative adenovirus (CRAd) from MSC using crystal violet staining, TCID₅₀assay, and quantitative PCR. In vitro killing competence of MSCs carrying Adv-Stat3(-) toward breast cancer and melanoma was performed using co-culture system of transwell plates. We examined tumor tropism of MSC by Prussian blue staining and immunofluorescence. In vivo killing competence of MSCs carrying Adv-Stat3(-) toward breast tumor was analyzed by comparison of tumor volumes and survival periods.</p> <p>Results</p> <p>Adv-Stat3(-) amplified in MSCs and were released 4 days after infection. MSCs carrying Adv-Stat3(-) caused viral amplification, depletion of Stat3 and its downstream proteins, and led to significant apoptosis in breast cancer and melanoma cell lines. In vivo experiments confirmed the preferential localization of MSCs in the tumor periphery 24 hours after tail vein injection, and this localization was mainly detected in the tumor parenchyma after 72 hours. Intravenous injection of MSCs carrying Adv-Stat3(-) suppressed the Stat3 pathway, down-regulated Ki67 expression, and recruited CD11b-positive cells in the local tumor, inhibiting tumor growth and increasing the survival of tumor-bearing mice.</p> <p>Conclusions</p> <p>These results indicate that MSCs migrate to the tumor site in a time-dependent manner and could be an effective platform for the targeted delivery of CRAd and the amplification of tumor killing effects.</p

Multi-axial fatigue life assessment of high speed car body based on PDMR method

This article mainly introduces a method of converting the acceleration signal of body bolster obtained by the circuit test into the load of the air spring seat of vehicle body. This method mainly decomposes the body's movement posture into the form of ups and downs, roll and nod. Then formulate the test plan according to the performance of the body fatigue test bench. The vertical and horizontal displacements and longitudinal force are used as control commands.Taking advantage of vehicle body fatigue test bench to reproduce these basic types of vibration. Establish the transfer function of the acceleration of the bolster and the displacement excitation of the air spring, and then obtaining the load of the air spring seat. Finally, the multi-axial fatigue life assessment of the vehicle body was performed using the obtained load combined with the Moment of Load Path Method and the Path-Dependent Maximum Range Method

ANALYSIS OF AERODYNAMIC LOAD ON FATIGUE STRENGTH OF THE HIGH-SPEED TRAIN CAR BODY

According to the actual circumstance of high-speed train in line operation four aerodynamic load cases are set up: pneumatic passing each other open wire,single train passing through tunnel,two trains passing by in tunnel and cross wind.Four types of aerodynamic load condition will be applied to the numerical finite element model of high-speed train car body. Then carry the fatigue strength of aerodynamic load analysis on the finite element model. The calculation data show that all maximum stress results under the four working conditions are less than the allowable stress of car body materials,the maximal displacement deformation occurred in the bottom of the car body. In the fatigue strength analysis,not only the vertical and lateral and aerodynamic loads combination is considered,but also a combination of longitudinal and aerodynamic loads is taken into accounted. According to the results of the fatigue assessment that a minimum safety margin is 2. 93 MPa,a minimum safety factor is 1. 083. Based on the results of the fatigue analysis that: car body structure meets the requirements of fatigue strength under the aerodynamic loads. The harsh conditions which are carried by car body at the same time are aerodynamic load and vertical load

STUDY ON VIBRATION FATIGUE CHARACTERISTICS OF SAFETY HANGER FOR METRO VEHICLE

Aiming at analyzing the reason of damage of safety hanger on metro vehicle,the finite element model and modal test was conducted for modal analysis.Finally,the natural modes near 340 Hz and 990 Hz were obtained.At the same time,in order to obtain the acceleration and dynamic stress level of the safety hanger in the operation process,a line tracking test was performed on the vehicle.According to the test data,it was found that due to the presence of rail corrugation excitation,the energy of the dynamic stress and acceleration at 340 Hz increased sharply,which indicates that the first-order mode was excited to generate resonance.According to the dynamic stress data before and after the rail corrugation,the fatigue life of the safety hanger was evaluated and compared.It is found that the fatigue damage caused by the rail corrugation greatly shortens the service life of the safety hanger

Simulation of Structure Dynamic Stress under Multi-load Condition in Resonance State

Some metro vehicle lifeguard structure cracking emerged during operation, and the reason is due to resonance. In order to simulate the dynamic stress accurately in resonance state, the formula for calculating the dynamic stress under multi-load condition was deduced based on structural dynamics mechanics. During the dynamic stress simulation, firstly, the frequency response function (FRF) of each external load was calculated, which including the phase information. Then, the method was based on Fast Fourier Transform (FFT) to get the frequency domain with real and imaginary part of each external load rather than power spectrum density (PSD) calculation, avoiding loss of the phase information due to PSD method. Finally, the dynamic stress frequency domain data could be calculated by FFT results and FRFs. Based on above, the dynamic stress time history could be acquired by Inverse FFT (IFFT) of stress frequency domain data, and the stress simulation method was verified by the line test result. Compared with the conventional stress PSD calculation method, the method in this paper can retain the phase information of the each external load. Meanwhile, the conventional stress simulation method based on PSD could not get satisfactory result

Field Measurements of Vibration on the Car Body-Suspended Equipment for High-Speed Rail Vehicles

The vibrations in the flexible car bodies of the high-speed electric multiple units (EMUs) and their coupling effects with the bogies and other types of equipment vibrating have lead issues for railway operators and gained interest for researchers. Other than a numerical investigation, field measurements on the vibrating characteristics of the car body (CB) and its suspended equipment (CBSE) for a high-speed railway vehicle were performed to elaborate the vibrating characteristics on the CB and its CBSE. In this long-term tracking test, the running stability of vehicle and wheel-rail interaction were also examined with the increase of operation distance (OD), a total of 2,400,000 km. The test configuration and arrangements are introduced first, followed by the data analysis in time and frequency domains. It is seen that the wheelset conicity increases 0.008 per 10,000 km, which increases approximately linearly with the OD from 0.10 to 0.40. Two types of wheel treads, S1002CN and LMB10, have different ranges in conicity and reprofiling cycles. The lateral accelerations on CB in a downward-running case (0.5 g) are much greater than that in upward-running case (0.2 g) corresponding to the vehicle stability differences. The 15 Hz low-pass filtered acceleration on CB experiences a maximum of 0.10 g and an averaged amplitude around 0.05 g, whereas the frequency spectrum has peaks of 0.01 g on CB and 0.1 g on CBSE. It states that an elastic suspension between the CBSE and the CB prevents the high-frequency vibration from the CB

Adenosine promotes IL-6 release in airway epithelia

In the airway epithelia, extracellular adenosine modulates a number of biological processes. However, little is known about adenosine's role in the inflammatory responses of airway epithelial cells. Recent studies suggest that the chronic elevation of extracellular adenosine in mice leads to pulmonary inflammation and fibrosis. Yet, the underlying molecular mechanism has not been well understood and little attention has been paid to the role of airway epithelia in adenosine-triggered inflammation. In the present work, we examined the role of adenosine in releasing IL-6 from airway epithelia. In Calu-3 human airway epithelial cells, apical but not basolateral adenosine elicited robust, apically polarized release of IL-6, along with proinflammatory IL-8. Both protein kinase A and protein kinase C mediated the adenosine-induced IL-6 release, at least partly via phosphorylation of CREB. Protein kinase C appeared to phosphorylate CREB through activating ERK. In addition, A2A but not A2B adenosine receptors were specifically required for the adenosine-induced IL-6 release. Furthermore, in rat bronchoalveolar lavage fluid, adenosine triggered the release of IL-6 as well as proinflammatory IL-1 beta. Adenosine also mediated the release of a considerable portion of the LPS-induced IL-6 in rat bronchoalveolar lavage fluid. Our findings provide a possible molecular link between extracellular adenosine elevation and lung inflammation and fibrosis