Plateau pressure

BACKGROUND: Acute lung injury (ALI) caused by hypobaric hypoxia (HH) is frequently observed in high-altitude areas, and it is one of the leading causes of death in high-altitude-related diseases due to its rapid onset and progression. However, the pathogenesis of HH-related ALI (HHALI) remains unclear, and effective treatment approaches are currently lacking. METHODS: A new mouse model of HHALI developed by our laboratory was used as the study subject (Chinese patent No...

To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger-Akah-Sunose (KAS) method...

OBJECTIVE: Intracranial pressure (ICP) monitoring is commonly utilized for identifying pathologic ICP in cases of traumatic brain injury; however, its utility in hydrocephalic children has not been elucidated. Although patients with typical (pressure-active) hydrocephalus present with clear signs and/or symptoms and the need for cerebrospinal fluid (CSF) diversion is often clear, others may have arrested or pressure-compensated hydrocephalus with pathologic ICP elevation masked by ambiguous signs or are completely asymptomatic...

OBJECTIVES: Prolonged intubation (PI) is a frequently encountered severe complication among patients following cardiac surgery (CS). Solely concentrating on preoperative data, devoid of sufficient consideration for the ongoing impact of surgical, anesthetic, and cardiopulmonary bypass procedures on subsequent respiratory system function, could potentially compromise the predictive accuracy of disease prognosis. In response to this challenge, we formulated and externally validated an intelligible prediction model tailored for CS patients, leveraging both preoperative information and early intensive care unit (ICU) data to facilitate early prophylaxis for PI...

OBJECTIVES: To evaluate analgesia, sedation and adverse effects of two doses of subcutaneous methadone in dogs undergoing tibial plateau levelling osteotomy. MATERIALS AND METHODS: Seventeen client-owned dogs undergoing unilateral tibial plateau levelling osteotomy were randomly allocated to receive either 0.25 mg/kg methadone (eight dogs) or 0.5 mg/kg methadone (nine dogs). All dogs were premedicated with methadone and 2 to 6 mcg/kg dexmedetomidine subcutaneously...

While earthquakes are well-known to trigger surface hazards and initiate hazard cascades, whether surface hazards can instead trigger earthquakes remains underexplored. In 2018, two landslides on the Tibetan plateau created landslide-dammed lakes which subsequently breached and caused catastrophic outburst floods. Here we build an earthquake catalog using machine-learning and cross-correlation-based methods which shows there was a statistically significant increase in earthquake activity (local magnitude ≤ 2...

A capsular tension ring (CTR) is used for support to stabilize the capsular bag and intraocular lens (IOL) during and after cataract surgery. Although complications involving the CTR-IOL complex are not uncommon, cases of anterior displacement leading to complications are rare. This report presents a case of secondary angle closure caused by anterior displacement of the CTR-IOL complex due to aqueous misdirection and reports unique findings noted on anterior segment optical coherence tomography (AS-OCT). The patient, a 69-year-old woman, developed an acute angle closure crisis (AACC) and underwent cataract surgery with the implantation of a CTR and IOL...

INTRODUCTION: The components of nighttime sap flux (En), which include transpiration (Qn) and stem water recharge (Rn), play important roles in water balance and drought adaptation in plant communities in water-limited regions. However, the quantitative and controlling factors of En components are unclear. METHODS: This study used the heat balance method to measure sap flow density in Vitex negundo on the Loess Plateau for a normal precipitation year (2021) and a wetter year (2022)...

UNLABELLED: The increasing lens vault (LV) and lens thickness (LT) is a recognized mechanism for primary angle closure glaucoma (PACG). Zonulopathy, causing the abnormal lens position, is an important factor in this mechanism. Several anatomically distinct sets of zonular fibers are present in primate eyes, including ciliary zonules, vitreous zonules and attachments between the posterior insertion zone of the vitreous zonules and the posterior lens equator (PVZ INS-LE strands). Zonulopathy, as a clinical diagnosis, exhibits zonular laxity and loss, long anterior lens zonules (LAZ)...

Frailty increases peri-operative risk, but details of its burden, clinical features and the risk of, and outcomes following, peri-operative cardiac arrest are lacking. As a preplanned analysis of the 7th National Audit Project of the Royal College of Anaesthetists, we described the characteristics of older patients living with frailty undergoing anaesthesia and surgery, and those reported to the peri-operative cardiac arrest case registry. In the activity survey, 1676 (26%) of 6466 patients aged > 65 y were reported as frail (Clinical Frailty Scale score ≥ 5)...

The generation of solid electrolyte interphase (SEI) largely determines the comprehensive performance of all-solid-state batteries. Herein, a novel "carrier-catalytic" integrated design is strategically exploited to in situ construct a stable LiF-LiBr rich SEI by improving the electron transfer kinetics to accelerate the bond-breaking dynamics. Specifically, the high electron transport capacity of Br-TPOM skeleton increases the polarity of C-Br, thus promoting the generation of LiBr...

OBJECTIVE: To investigate the clinical effect of helium-oxygen mechanical ventilation on inflammation of the diseased lung segment and diaphragm function in patients with acute respiratory distress syndrome (ARDS) caused by pneumonia who suffered difficulty weaning from mechanical ventilation. METHODS: A prospective controlled study was conducted. A total of 40 patients with ARDS caused by pneumonia and requiring tracheal intubation with difficulty weaning from mechanical ventilation, admitted to the department of critical care medicine in Pingtan Branch of Fujian Medical University Union Hospital from October 2020 to December 2021 were enrolled...

This protocol outlines an acute respiratory distress model utilizing centrally administered oleic acid infusion in Yorkshire pigs. Prior to experimentation, each pig underwent general anesthesia, endotracheal intubation, and mechanical ventilation, and was equipped with bilateral jugular vein central vascular access catheters. Oleic acid was administered through a dedicated pulmonary artery catheter at a rate of 0.2 mL/kg/h. The infusion lasted for 60-120 min, inducing respiratory distress. Throughout the experiment, various parameters including heart rate, respiratory rate, arterial blood pressure, central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, end-tidal carbon dioxide, peak airway pressures, and plateau pressures were monitored...

Vortex-based hydrodynamic cavitation offers an effective platform for producing emulsions. In this work, we have investigated characteristics of dense oil in water emulsions with oil volume fractions up to 60% produced using a vortex-based cavitation device. Emulsions were prepared using rapeseed oil with oil volume fractions of 0.15, 0.3, 0.45, and 0.6. For each of these volume fractions, the pressure drop as a function of the flow rate of emulsions through the cavitation device was measured. These data were used for estimating the effective viscosity of the emulsions...

INTRODUCTION: Electrical-equivalence mathematical models that integrate vascular and cerebrospinal fluid (CSF) compartments perform well in simulations of dynamic cerebrovascular variations and their transient effects on intracranial pressure (ICP). However, ICP changes due to sustained vascular diameter changes have not been comprehensively examined. We hypothesise that changes in cerebrovascular resistance (CVR) alter the resistance of the bulk flow of interstitial fluid (ISF). RESEARCH QUESTION: We hypothesise that changes in CVR alter the resistance of the bulk flow of ISF, thus allowing simulations of ICP in response to sustained vascular diameter changes...

BACKGROUND: Prone positioning (PP) homogenizes ventilation distribution and may limit ventilator-induced lung injury (VILI) in patients with moderate to severe acute respiratory distress syndrome (ARDS). The static and dynamic components of ventilation that may cause VILI have been aggregated in mechanical power, considered a unifying driver of VILI. PP may affect mechanical power components differently due to changes in respiratory mechanics; however, the effects of PP on lung mechanical power components are unclear...

BACKGROUND: Ambient air pollution could increase the risk of hypertension; however, evidence regarding the relationship between long-term exposure to particulate matter and elevated blood pressure in plateau areas with lower pollution levels is limited. METHODS: We assessed the associations of long-term exposure to particulate matter (PM, PM1 , PM2.5 , and PM10 ) with hypertension, diastolic blood pressure (DBP), systolic blood pressure (SBP) and pulse pressure (PP) in 4...

BACKGROUND AND AIMS: The use of a face mask while inducing general anaesthesia (GA) in obese patients is often ineffective in providing adequate ventilation. Although nasal mask ventilation has demonstrated effectiveness for continuous positive airway pressure (CPAP) in obese patients with obstructive sleep apnoea (OSA), it has not yet been applied to the induction of anaesthesia. This study evaluated the efficacy of nasal mask ventilation against standard face mask ventilation in anaesthetised obese patients with body mass index (BMI)>25 kg/m2 ...

In this study, we conducted an assembly and analysis of the organelle genomes of Aconitum carmichaelii. Our investigation encompassed the examination of organelle genome structures, gene transfer events, and the environmental selection pressures affecting A. carmichaelii. The results revealed distinct evolutionary patterns in the organelle genomes of A. carmichaelii. Especially, the plastome exhibited a more conserved structure but a higher nucleotide substitution rate (NSR), while the mitogenome displayed a more complex structure with a slower NSR...

The Tibetan Plateau (TP) is essential in modulating climate change in downstream Eastern China (EC). As a meteorology-sensitive pollutant, changes in O3 in connection with the TP have received limited attention. In this study, using climate analysis of the China High Air Pollutants O3 product and ERA5 reanalysis data of meteorology for 1980-2020, the effect of springtime TP thermal forcing on the warm season (April-September) O3 pollution over EC was investigated. The strong TP thermal effect significantly modulates the interannual variations in O3 pollution with a dipole pattern over EC, inducing more O3 pollution in northern EC regions and alleviating O3 pollution in the southern regions...