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The flow field that evolves inside a duct upon the departure of a shock wave from its open exit is studied experimentally. The present investigation covers a relatively long time period, almost until the shock-induced flow inside the duct ceases. During the investigated time period, the appearance of a second shock wave is observed inside the duct. The effect of introducing a door inclined to the duct’s exit plane, on the pressure field developed behind the second shock is reported. Three different inclination angles are studied, 30°, 45°, and 90° relative to the duct’s exit plane. It is shown that keeping the exit door at different angles and, thereby changing the size of the exit area, has a direct effect on the pressures prevailing inside the tube and on the exit door. The highest pressure on the door and the lowest pressure behind the second shock wave are observed when the exit door is kept at an angle of 30°. [ABSTRACT FROM AUTHOR]

The trypsin inhibitor activity (TIA) of five varieties of beans (Phaseolus vulgaris L.) namely, Carioca, Branco,Vermelho, Preto and Jab, was investigated. No significant differences of TIA among varieties of raw beans were observed (P > 0.05). Pressure-cooking (121°C and 141 kPa) for 15 mm resulted in complete inactivation of TIA. On cooking beans in water bath (90°C, 15mm, the TIA was inactivated between 80% and 95%, while total inactivation was achieved after 40mm suggesting the possibility of two-step inactivation kinetics. Microwave treatment was very effective for inactivation of this antinutritional factor (97% to 100% of inactivation) in the first 15mm of treatment. A 22 factorial design was developed to evaluate the effect of temperature and duration of thermal treatment for loss of TIA. As interdependence between temperature and time was evident, it is envisaged that both are important to process the beans to knock off TIA. [ABSTRACT FROM AUTHOR]

Double replica TEM of etched (100) GaAs surfaces has shown that acidic etching gives rough island-type features whereas alkaline solutions seem to produce smooth surfaces. [ABSTRACT FROM AUTHOR]

The dispersion of particles by blast or shock waves induces the formation of coherent structures taking the shape of particle jets. In the present study, a blast wave, issued from an open shock tube, is generated at the center of a granular ring initially confined in a Hele-Shaw cell. With the present experimental setup, solid particle jet formation is clearly observed in a quasi-two-dimensional configuration. In all instances, the jets are initially generated inside the particle ring and thereafter expelled outward. Furthermore, thanks to the two-dimensional experimental configuration, a general study of the main parameters involved in these types of flows can be performed. Among them, the particle diameter, the density of the particles, the initial size of the ring, the shape of the overpressure generated and the surface friction of the Hele-Shaw cell are investigated. Empirical relationships are deduced from experimental results. [ABSTRACT FROM AUTHOR]

The behavior of an aluminum door hanging at the exit of an open shock tube at different angles, from 5 $$^\circ $$ to 85 $$^\circ $$, and thereby providing partially open space for the exiting flow, was investigated experimentally. Experiments were conducted with an incident shock wave Mach number of $$M_\mathrm{is}=1.1$$ impinging on the partially opened door. Both pressure measurements in the vicinity of the door, on its center and inside the shock tube, and schlieren visualization were undertaken for studying the door movement and its maximum opening angle relative to its initial position. It was found that for an initial opening angle smaller than 25 $$^\circ $$ the door opened completely while for larger angles its motion is marginal. In addition, for an initial door opening angle of about 10 $$^\circ $$ the lowest pressures were recorded inside the shock tube behind the evolving waves after exiting of the incident shock wave. The present experimental results may be useful to numerical studies of fluid-structure interactions, e.g., in designing safety valves in jet engines. Such a device is needed for preventing rupture in the case when a sudden overpressure pulse is generated inside the aircraft engine compartment. [ABSTRACT FROM AUTHOR]

Numerical modeling of the interaction between a cloud of water droplets and a planar shock wave is compared with experimental data. The mathematical model relies on an Eulerian description of the dispersed phase with the assumption of dilute flows. It is shown that the secondary atomization of the droplets strongly influences the structure of both the shock wave and the induced flow. After shock loading, the individual liquid components generate daughter droplets, and the overall interphase surface per unit volume undergoes strong variations which modify the pressure relaxation process towards a dynamic and thermal equilibrium state. The experimental data enable one to determine the best analytical formulation of the droplet number production rate. Models of droplet number production rate are compared in order to highlight this feature. The model based on the assumption of linear variation of droplet diameter with time gives the best agreement between the numerical results and the experimental data. [ABSTRACT FROM AUTHOR]

In a conventional shock tube, the driver and the driven sections have similar (if not identical) cross-sectional area and the diaphragm opened area, upon rupturing, is practically equal to the tube cross-sectional area. Such geometry results in generating a well-formed shock wave in the tube's driven section. The present experimental work checks the effects that changes in the diaphragm ruptured area have on the generated shock and rarefaction waves. Experiments were conducted in an 80 mm by 80 mm cross section shock tube generating incident shock waves having Mach numbers within the range from 1.06 to 1.25. In each run, pressure histories were recorded along the driven and the driver sections of the shock tube. The recorded pressures reveal that progressive reduction in the diaphragm open space resulted in a weaker shock and both longer time and distance until the compression waves generated close to the diaphragm coalesces into a shock wave. In addition, reducing the open space of the diaphragm resulted in a significant slow down in the high pressure reduction prevailing in the driver section. [ABSTRACT FROM AUTHOR]

This paper proposes a study on the resilience to radiation of MEMS sensors based on piezoresistive transduction by means of suspended silicon nanogauges. It is particularly interesting for applications in severe environment like in space or in nuclear plant. This work shows that the resistivity of a single nanogauge exhibits a sensitivity of 16.5 ppm/kGy whereas the silicon nanogauges bridge used for MEMS transduction is immune to radiation with a variation of −4 ppm/h, like in normal operation. It is the consequence of the differential measurement at the terminals of the two nanogauges that enables to cancel radiation effects. [ABSTRACT FROM AUTHOR]

We present an optomechanical method for locally measuring the rheological properties of complex fluids in the ultra-high frequency range (UHF). A mechanical disk of microscale volume is used as an oscillating probe that monitors a liquid at rest, while the oscillation is optomechanically transduced. An analytical model for fluid-structure interactions is used to deduce the rheological properties of the liquid. This method is calibrated on liquid water, which despite pronounced compressibility effects remains Newtonian over the explored range. In contrast, liquid 1-decanol exhibits a non-Newtonian behavior, with a frequency-dependent viscosity showing two relaxation times of 797 and 151 picoseconds, associated to supramolecular and intramolecular processes. A shear elastic response appears at the highest frequencies, whose value allows determining the volume of a single liquid molecule. UHF optomechanical micro-rheology provides direct mechanical access to the fast molecular dynamics in a liquid, in a quantitative manner and within a sub-millisecond measurement time., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Objectives: This study was designed to prospectively evaluate the feasibility of an opioid-free anesthesia protocol and describe the quality of recovery and management of postoperative analgesia in dogs after a tibial plateau leveling osteotomy (TPLO)., Methods: In total, 20 dogs presented for TPLO were included. After premedication with intravenous (IV) medetomidine (0.005-0.007 mg/kg) and midazolam (0.2 mg/kg), the dogs were anesthetized using ketamine (2 mg/kg) and propofol and maintained with isoflurane and ketamine CRI (0.6 mg/kg/h). Sciatic and femoral nerve blocks were performed with bupivacaine 0.5% (0.087 +/- 0.01 and 0.09 +/- 0.02 mL/kg, respectively). Meloxicam (0.2 mg/kg IV) was administered intraoperatively, after osteotomy. Fentanyl (0.002 mg/kg IV) was administered intraoperatively, as rescue analgesia in the case of sustained increase in cardiorespiratory variables. Two pain scores (French 4A-VET and Glasgow short form) were performed at conscious sternal recumbency and 2, 4, 6, 8, 12, and 20 h after extubation and compared to baseline using a Friedman test followed by a Nemenyi post-hoc test. The time taken for the first food intake and urination was reported., Results: Intraoperative opioid-free anesthesia was feasible in 11 dogs, whereas 9 dogs received fentanyl once during arthrotomy. No opioid postoperative rescue analgesia was required. Food intake occurred within 6 h, and all dogs were discharged after 24 h without any complication., Conclusion: Total opioid-free postoperative analgesia was achieved in all dogs, with adequate recoveries. Although opioid-free anesthesia was feasible in 55% of the population, a single dose of fentanyl was necessary in 45% of the dogs during arthrotomy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Didier, Faucher, Sarra Ferrer, Lapouge, Junot and Jourdan.)

The canine diaphragm is a muscular and tendinous dome-like plate and is largely involved in digestive and respiratory functions. Very few studies compared morphology of the diaphragm between dogs and cats and no studies have investigated the effects of individual factors on this morphology. So the aim of this study was to (1) study the effects of individual factors on the morphology of the diaphragm and (2) to compare its morphology between cats and dogs. Surface measurements of 86 diaphragms were performed. The tendinous centre (TC), the lumbar part of the peripheral muscular (LP) and the sternal and costal parts of the peripheral muscular (SCPM) were measured. Measurement ratios (surface of anatomical part of the diaphragm/total surface of the diaphragm) were used for statistical analysis (TC%S, LP%S, SCPM%S). The SCPM%S are significantly lower, and the LP%S are significantly higher when bodyweight increases in dogs and cats. The TC%S are significantly lower when the body condition score of dogs increases. The SCPM%S are significantly higher, and therefore, the TC%S and LP%S lower in brachycephalic animals as opposed to mesocephalic animals. The TC%S are significantly higher in dogs than in cats and the SCPM%S are significantly higher in cats than in dogs. This study proposed a cartography of the diaphragm morphology in cats and dogs taking into account individual animal factors. Significant differences in the diaphragm morphology between cats and dogs and between mesocephalic and brachycephalic animals were found. Further studies are necessary to confirm these results and to investigate the consequences of these variations., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

(1) Background: Individuals with COVID-19 display different forms of disease severity and the upper respiratory tract microbiome has been suggested to play a crucial role in the development of its symptoms. (2) Methods: The present study analyzed the microbial profiles of the oral cavity and oropharynx of 182 COVID-19 patients compared to 75 unaffected individuals. The samples were obtained from gargle screening samples. 16S rRNA amplicon sequencing was applied to analyze the samples. (3) Results: The present study shows that SARS-CoV-2 infection induced significant differences in bacterial community assemblages, with Prevotella and Veillonella as biomarkers for positive-tested people and Streptococcus and Actinomyces for negative-tested people. It also suggests a state of dysbiosis on the part of the infected individuals due to significant differences in the bacterial community in favor of a microbiome richer in opportunistic pathogens. (4) Conclusions: SARS-CoV-2 infection induces dysbiosis in the upper respiratory tract. The identification of these opportunistic pathogenic biomarkers could be a new screening and prevention tool for people with prior dysbiosis.

Background : Lingering symptoms are frequently reported after acute SARS-CoV-2 infection, a condition known as post-COVID-19 condition (PCC). The duration and severity of PCC in immunologically naïve persons remain unclear. Furthermore, the long-term consequences of these chronic symptoms on work and mental health are poorly documented. Objective : To determine the outcome, the risk factors, and the impact on work and mental health associated with post-COVID-19 symptoms. Methods : This prospective population-based study assessed acute COVID-19 symptoms and their evolution for up to nine months following infection. Individuals aged 18 years and older with COVID-19 in three Canadian regions between 1 November 2020 and 31 May 2021 were recruited. Participants completed a questionnaire that was either administered by trained student investigators over the phone or self-administered online. Results : A total of 1349 participants with a mean age of 46.6 ± 16.0 years completed the questionnaire. Participants were mostly unvaccinated at the time of their COVID-19 episode (86.9%). Six hundred and twenty-two participants (48.0%) exhibited one symptom or more, at least three months post-COVID-19. Among participants with PCC, 23.0% to 37.8% experienced fatigue at the time of survey. Moreover, 6.1% expressed psychological distress. Risk factors for PCC and fatigue included female sex (OR = 1.996), higher number of symptoms (OR = 1.292), higher severity of episode (OR = 3.831), and having a mental health condition prior to the COVID-19 episode (OR = 5.155). Conclusions : In this multicenter cohort study, almost half (47%) of the participants reported persistent symptoms >3 months after acute infection. Baseline risk factors for PCC include female sex, number and severity of symptoms during acute infection, and a previous diagnosis of mental health disorder. Having PCC negatively impacted health-related quality of life and these patients were more likely to exhibit psychological distress, as well as fatigue.

Adipose-derived mesenchymal stromal cells (ASC) transplant to recover the optimal tissue structure/function relationship is a promising strategy to regenerate tissue lesions. Because filling local tissue defects by injection alone is often challenging, designing adequate cell carriers with suitable characteristics is critical for in situ ASC delivery. The aim of this study was to optimize the generation phase of a platelet-lysate-based fibrin hydrogel (PLFH) as a proper carrier for in situ ASC implantation and (1) to investigate in vitro PLFH biomechanical properties, cell viability, proliferation and migration sustainability, and (2) to comprehensively assess the local in vivo PLFH/ASC safety profile (local tolerance, ASC fate, biodistribution and toxicity). We first defined the experimental conditions to enhance physicochemical properties and microscopic features of PLFH as an adequate ASC vehicle. When ASC were mixed with PLFH, in vitro assays exhibited hydrogel supporting cell migration, viability and proliferation. In vivo local subcutaneous and subgingival PLFH/ASC administration in nude mice allowed us to generate biosafety data, including biodegradability, tolerance, ASC fate and engraftment, and the absence of biodistribution and toxicity to non-target tissues. Our data strongly suggest that this novel combined ATMP for in situ administration is safe with an efficient local ASC engraftment, supporting the further development for human clinical cell therapy.

A dog was examined because of acute onset of respiratory distress following a cervical dog bite. Physical examination revealed a deep ventral cervical bite wound associated with localized mild subcutaneous emphysema. Thoracic radiographs showed moderate pneumomediastinum. Medical management consisting of oxygen therapy, antibiotics, and anti-inflammatories was initiated. After 2 days, respiratory distress suddenly worsened. Tracheoscopy showed a discontinuity between the tracheal rings of the cervical trachea; however, the inner tracheal wall appeared intact. Computed tomography scan revealed a ~3-cm complete rupture of all layers of the trachea. Surgical resection and anastomosis of the trachea were performed successfully. Follow-up 15 days after surgery showed complete resolution of respiratory signs, as well as subcutaneous emphysema. A mild ventral angulation of the trachea at the surgical site was noticed on thoracic radiographs. This is the first case report of a pseudotrachea in a dog. Persistence of a pseudotrachea may initially result in only minor clinical signs responsive to medical therapy despite tracheal rupture. In the presence of a pseudotrachea, tracheal rupture may be difficult to identify with tracheoscopy alone. Therefore, CT scan should be proposed in every patient with suspected tracheal trauma. Key clinical message: This case report highlights the importance of including a tracheal rupture in the differential diagnosis of cervical subcutaneous emphysema, even if the amount is small and not associated with significant respiratory signs. The presence of a pseudotrachea may result in less severe clinical signs than expected based on the actual degree of tracheal injury; however, the clinical status may rapidly deteriorate and become life-threatening. This case report also underlines the importance of a CT scan as a complement to tracheoscopy, which may not be sufficient to identify a tracheal rupture in the presence of a pseudotrachea., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Atomic force microscopy (AFM) has been consistently supporting nanosciences and nanotechnologies for over 30 years and is used in many fields from condensed matter physics to biology. It enables the measurement of very weak forces at the nanoscale, thus elucidating the interactions at play in fundamental processes. Here, we leverage the combined benefits of micro/nanoelectromechanical systems and cavity optomechanics to fabricate a sensor for dynamic mode AFM at a frequency above 100 MHz. This frequency is two decades above the fastest commercial AFM probes, suggesting an opportunity for measuring forces at timescales unexplored thus far. The fabrication is achieved using very-large-scale integration technologies derived from photonic silicon circuits. The probe's optomechanical ring cavity is coupled to a 1.55 μm laser light and features a 130 MHz mechanical resonance mode with a quality factor of 900 in air. A limit of detection in the displacement of 3 × 10 -16  m/√Hz is obtained, enabling the detection of the Brownian motion of the probe and paving the way for force sensing experiments in the dynamic mode with a working vibration amplitude in the picometer range. When inserted in a custom AFM instrument embodiment, this optomechanical sensor demonstrates the capacity to perform force-distance measurements and to maintain a constant interaction strength between the tip and sample, an essential requirement for AFM applications. Experiments indeed show a stable closed-loop operation with a setpoint of 4 nN/nm for an unprecedented subpicometer vibration amplitude, where the tip-sample interaction is mediated by a stretched water meniscus., Competing Interests: Conflict of interestThe authors declare no competing interests., (© The Author(s) 2022.)

Nanoelectromechanical resonators have been successfully used for a variety of sensing applications. Their extreme resolution comes from their small size, which strongly limits their capture area. This leads to a long analysis time and the requirement for large sample quantity. Moreover, the efficiency of the electrical transductions commonly used for silicon resonators degrades with increasing frequency, limiting the achievable mechanical bandwidth and throughput. Multiplexing a large number of high-frequency resonators appears to be a solution, but this is complex with electrical transductions. We propose here a route to solve these issues, with a multiplexing scheme for very high-frequency optomechanical resonators. We demonstrate the simultaneous frequency measurement of three silicon microdisks fabricated with a 200 mm wafer large-scale process. The readout architecture is simple and does not degrade the sensing resolutions. This paves the way toward the realization of sensors for multiparametric analysis with an extremely low limit of detection and response time.