Pressure-volume Curves Research Articles

A Volumetric Study of Flux Transfer Events at the Dayside Magnetopause

Localized magnetic reconnection at the dayside magnetopause leads to the production of Flux Transfer Events (FTEs). The magnetic fields within the FTEs exhibit complex helical flux-rope topologies. Leveraging the adaptive mesh refinement strategy, we perform a three-dimensional magnetohydrodynamic simulation of the magnetosphere of an Earth-like planet and study the evolution of these FTEs. For the first time, we detect and track the FTE structures in 3D and present a complete volumetric picture of FTE evolution. The temporal evolutions of thermodynamic quantities within the FTE volumes confirm that continuous reconnection is indeed the dominant cause of active FTE growth, as indicated by the deviation of the pressure–volume curves from an adiabatic profile. An investigation into the magnetic properties of the FTEs shows a rapid decrease in the perpendicular currents within the FTE volume, exhibiting the tendency of internal currents toward being field-aligned. An assessment of the validity of the linear force-free flux-rope model for such FTEs shows that the structures drift toward a constant-α state but continuous reconnection inhibits the attainment of a purely linear force-free configuration. Additionally, the fluxes enclosed by the selected FTEs are computed to range between 0.3 and 1.5 MWb. The FTE with the highest flux content constitutes ∼1% of the net dayside open flux. These flux values are further compared against the estimates provided by the linear force-free flux-rope model. For the selected FTEs, the linear force-free model underestimated the flux content by up to 40%, owing to the continuous reconnected flux injection.

Quantitative lung ultrasound detects dynamic changes in lung recruitment in the preterm lamb

BackgroundLung ultrasound (LUS) may not detect small, dynamic changes in lung volume. Mean greyscale measurement using computer-assisted image analysis (Q-LUSMGV) may improve the precision of these measurements.MethodsPreterm lambs (n = 40) underwent LUS of the dependent or non-dependent lung during static pressure–volume curve mapping. Total and regional lung volumes were determined using the super-syringe technique and electrical impedance tomography. Q-LUSMGV and gold standard measurements of lung volume were compared in 520 images.ResultsDependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.60, 95% CI 0.51–0.67) and fairly with right whole (rho = 0.39, 0.27–0.49), central (rho = 0.38, 0.27–0.48), ventral (rho = 0.41, 0.31–0.51) and dorsal regional lung volumes (rho = 0.32, 0.21–0.43). Non-dependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.57, 0.48–0.65) and fairly with right whole (rho = 0.43, 0.32–0.52), central (rho = 0.46, 0.35–0.55), ventral (rho = 0.36, 0.25–0.47) and dorsal lung volumes (rho = 0.36, 0.25–0.47). All correlation coefficients were statistically significant. Distinct inflation and deflation limbs, and sonographic pulmonary hysteresis occurred in 95% of lambs. The greatest changes in Q-LUSMGV occurred at the opening and closing pressures.ConclusionQ-LUSMGV detected changes in total and regional lung volume and offers objective quantification of LUS images, and may improve bedside discrimination of real-time changes in lung volume.ImpactLung ultrasound (LUS) offers continuous, radiation-free imaging that may play a role in assessing lung recruitment but may not detect small changes in lung volume.Mean greyscale image analysis using computer-assisted quantitative LUS (Q-LUSMGV) moderately correlated with changes in total and regional lung volume.Q-LUSMGV identified opening and closing pressure and pulmonary hysteresis in 95% of lambs.Computer-assisted image analysis may enhance LUS estimation of lung recruitment at the bedside.Future research should focus on improving precision prior to clinical translation.

Divergent leaf and fine root "pressure-volume relationships" across habitats with varying water availability.

Fine roots and leaves, the direct interfaces of plants with their external environment along the soil-plant-atmosphere continuum, are at the front line to ensure plant adaptation to their growing habitat. This study aimed to compare the vulnerability to water deficit of fine roots and leaves of woody species from karst and mangrove forests-two water-stressed habitats-against that of timber and ornamental woody species grown in a well-watered common garden. Thus, pressure-volume curves in both organs of 37 species (about 12 species from each habitat) were constructed. Fine roots wilted at a less negative water potential than leaves in 32 species and before branch xylem lost 50% of its hydraulic conductivity in the 17 species with available data on branch xylem embolism resistance. Thus, turgor loss in fine roots can act as a hydraulic fuse mechanism against water stress. Mangroves had higher leaf resistance against wilting and lower leaf-specific area than the karst and common garden plants. Their fine roots had high specific root lengths (SRL) and high capacitance to buffer water stress. Karst species had high leaf bulk modulus, low leaf capacitance, and delayed fine root wilting. This study showed the general contribution of fine roots to the protection of the whole plant against underground water stress. Our findings highlight the importance of water storage in the leaves and fine roots of mangrove species and high tolerance to water deficit in the leaves of mangrove species and the fine roots of some karst species.

Safety-efficiency tradeoffs? Correlations of photosynthesis, leaf hydraulics, and dehydration tolerance across species.

The tradeoffs between carbon assimilation and hydraulic efficiencies and drought-tolerance traits on different scales are considered a central tenet in plant ecophysiology; however, no clear tradeoff between these traits has emerged in previous studies using woody angiosperms or grasses by investigating several hydraulic tolerance and gas exchange efficiency and/or water transport efficiency traits. In this study, we measured numerous efficiency, resistance, and leaf anatomical traits, including light-saturated gas exchange, leaf hydraulic vulnerability curves, pressure-volume curves, and leaf anatomical traits, in seven species with diverse drought tolerance. A substantial variation in photosynthetic rate, stomatal conductance, mesophyll conductance, maximum leaf hydraulic conductance (Kmax), mesophyll anatomical traits, and leaf vein density across species was observed. Both mesophyll conductance and Kmax were related to leaf anatomical traits, but other gas exchange traits were decoupled from Kmax. Although the efficiency and tolerance traits varied widely across estimated species, no clear trade-off between safety traits and efficiency traits was observed. These findings suggested that postulated leaf-level drought tolerance-carbon assimilation and hydraulic efficiency tradeoff does not exist among distant species and that the fact that different leaf anatomical traits determine efficiency and tolerance capacity might contribute to the lack of such tradeoffs.

A Water Balloon as an Innovative Energy Storage Medium.

Soft rubbery materials are capable of withstanding large deformation, and stretched rubber contracts when heated. Additionally, rubber balloons exhibit non-monotonic pressure–volume curves. These unique properties have inspired numerous ingenious inventions based on rubber balloons. To the authors’ knowledge, however, it is surprising that these properties have not inspired any study that exploits the elasticity of rubber balloons for energy storage. Motivated by these, this study examines the performance of water balloons as energy storage media. In each experiment, a single water balloon is implemented using a flat membrane, and it is subject to repeated inflation, heating, deflation, and cooling. Inflating the balloon deposits energy into it. The heating simulates the recycling of waste heat. The balloon delivers work during its deflation. Finally, the cooling completes the energy-storage cycle. The performance is evaluated in terms of the balloon’s transferred energies, efficiencies, and service life. Simple as it is, a water balloon is actually an impressively efficient energy storage medium. The efficiency is 85–90% when a water balloon stores and releases energy at room temperature. Recycling waste heat can boost a balloon’s efficiency beyond 100%, provided that the cost of the heat is negligible so that the heat is not taken as part of the input energy. However, heating shortens the service life of a balloon and reduces the total energy it can accommodate. By running fatigue tests on balloons, this study reveals the trade-off between a water balloon’s efficiency and its longevity. These results shall serve as a useful guide for implementing balloon-based mechanical devices not limited to energy-storage applications.

(-)-Epicatechin Ameliorates Cardiac Fibrosis in a Female Rat Model of Pre-Heart Failure with Preserved Ejection Fraction.

One of the most abundant flavonoids present in cacao is (-)-epicatechin (Epi) and this flavanol has been linked to the cardiovascular health promoting actions of cocoa products. We previously demonstrated that Epi reduces infarct size in rodent models of ischemia/reperfusion and permanent coronary occlusion. Reduced infarct size was associated with decreased left ventricular (LV) oxidative stress (OS) and indicators of inflammation factors, which foster myocardial fibrosis. In this study, we examine the antifibrotic actions of Epi in an aging female rat model of pre-heart failure with preserved ejection fraction (pre-HFpEF) as well as its potential to mitigate plasma levels of OS, proinflammatory/profibrotic cytokines, and improve passive and active LV function. Epi treatment [1 mg/(kg·d)] was provided daily by gavage from 21 to 22 months of age, whereas controls received water. A Millar catheter was used to assess hemodynamic function. Subsequently, hearts were arrested in diastole, a balloon inserted into the LV and passive pressure-volume curves generated. Fixed LV sections were processed for collagen area fraction quantification using Sirius Red staining. Treatment with Epi did not lead to detectable changes in LV contractile function. However, passive LV pressure volume curves were significantly right shifted with Epi. Collagen area fraction values indicated that Epi treatment significantly reduces LV fibrosis. Epi also significantly reduced plasma OS markers and levels of profibrotic and proinflammatory cytokines. In conclusion, Epi reduces cardiac fibrosis in an aged, female rat model of pre-HFpEF, which correlates with significant reductions in OS and cytokine levels in the absence of changes in LV contractile function.

Myocardial work – are we ready for a new parameter in clinical practice for evaluating left ventricle function?

Left ventricle systolic function is an essential parameter in different clinical scenarios and the usual methods available for its assessment are sometime suboptimal, depending on the filling conditions of the heart. Therefore, the development and implementation in clinical practice of a new parameter for assessing left ventricle contractile function is desirable. Mechanical work defined as energy transferred to or from an object via the application of force along a displacement seems to be a promising method for myocardial performance estimation. Although initially this parameter was calculated on the left ventricle volume-pressure curve estimated by cardiac catheterization, an easier method considering non-invasive left ventricle pressure and global longitudinal strain assessed by speckle tracking echocardiography was developed recently. Myocardial work offers information regarding the segmental and global function of the left ventricle, and it is considered a more sensitive marker for assessing left ventricle performance compared to ejection fraction and global longitudinal strain. Its applicability in various cardiac pathologies was demonstrated recently in several studies and its use in every day practice may bring important additional information for clinical decision making

Modeling the influence of gravity and the mechanical properties of elastin and collagen fibers on alveolar and lung pressure–volume curves

The relationship between pressure (P) and volume (V) in the human lung has been extensively studied. However, the combined effects of gravity and the mechanical properties of elastin and collagen on alveolar and lung P–V curves during breathing are not well understood. Here, we extended a previously established thick-walled spherical model of a single alveolus with wavy collagen fibers during positive pressure inflation. First, we updated the model for negative pressure-driven inflation that allowed incorporation of a gravity-induced pleural pressure gradient to predict how the static alveolar P–V relations vary spatially throughout an upright human lung. Second, by introducing dynamic surface tension and collagen viscoelasticity, we computed the hysteresis loop of the lung P–V curve. The model was tested by comparing its predicted regional ventilation to literature data, which offered insight into the effects of microgravity on ventilation. The model has also produced novel testable predictions for future experiments about the variation of mechanical stresses in the septal walls and the contribution of collagen and elastin fibers to the P–V curve and throughout the lung. The model may help us better understand how mechanical stresses arising from breathing and pleural pressure variations affect regional cellular mechanotransduction in the lung.

Relative growth rate for trees at the growth stage is coordinated with leaf bulk modulus of elasticity and osmotic potential in a subtropical forest of China

Current theoretical models for tree relative growth rate (RGR) have considered physiological processes based on carbon economy and nutrient-productivity relations, but have not taken water relations into account. According to the ecological energetics and Lockhart equation theories, if more energy is needed to maintain water balance in plants, less energy should be invested towards growth, resulting in a trade-off between growth and drought tolerance. Leaf pressure–volume (PV) curve parameters are the best recognised classical indicators of plant drought tolerance, however, the relationships between tree growth and leaf PV parameters have rarely been investigated in forest communities. In the study, we selected two evergreen (Lithocarpus glaber, Cyclobalanopsis oxyodon) and two deciduous species (Quercus serrata, Platycarya strobilacea) that dominate northern subtropical forests on Mt. Shennongjia, central China. For each species, we selected individuals at different developmental stages (growth vs. mature stage), and measured the relative growth rate of diameter at breast height (RGRDBH) and leaf PV curve parameters, including leaf saturated osmotic potential (Ψsat), maximum bulk elastic modulus (εmax), turgor loss osmotic potential (Ψtlp) and leaf water capacity (Cleaf). Correlation analysis and structural equation models (SEM) were applied to explore the relationships between RGRDBH and PV parameters. The results showed that: 1) at both stages, RGRDBH was positively correlated with Ψsat, but not with Ψtlp and Cleaf; 2) εmax was negatively related to RGRDBH at the growth stage; 3) the relationship between PV parameters and RGRDBH was determined mainly by inter-specific difference; 4) SEM showed that both Ψtlp and Ψsat were affected by εmax; and 5) due to the interaction between the PV parameters, Ψsat and εmax had a direct effect on RGRDBH only during the growth stage. Our results showed that the functional/structural coordination between PV parameters adjusted the RGRDBH of trees, and among different species, there exists a tradeoff between energy allocation for drought tolerance and growth. These findings can be applied to improve RGR models, and show how forests respond to warm-induced drought, which is a major threat to global forests in a future warmer climate.

Validation of lung sonography in the implementation of open lung strategy as a recruitment maneuver versus traditional sustained inflation in acute respiratory distress syndrome patients

Introduction Acute respiratory distress syndrome (ARDS) is a serious problem in critically ill patients with high mortality rates. Lung recruitment maneuvers (RM) are important in the treatment of ARDS with an aim to improve oxygenation. There are many approved methods for lung recruitment like the traditional sustained inflation technique and the stepladder positive end-expiratory pressure (PEEP) titration technique. The traditional methods to evaluate RM like computed tomography and pressure–volume curves showed some limitation and disadvantages. Thus, bedside ultrasonography (US) could be a safe bedside tool to evaluate lung aeration and the effectiveness of RM defining the optimum PEEP needed and preventing lung overdistension. Aim To evaluate the usefulness of lung US as a guide to follow up RM by PEEP titration technique in comparison to sustained inflation technique. Patients and methods In all, 40 ARDS patients were segregated into two groups: group 1 included 20 patients who were subjected to traditional sustained inflation RM and group 2 included 20 patients were subjected to sonar-guided lung recruitment. US scoring, PO2, PO2/FiO2, and lung compliance were used to evaluate the pulmonary recruitment end point defining the best PEEP. Results Lung compliance, PO2, and PO2/FiO2 were significantly increased after RM in both groups (P<0.05); however, there was no statistically significant difference between the two groups. The best PEEP in group 1 and group 2 were 20.60±3.485 and 15.90±5.340, respectively, with a significant difference between the two groups (P=0.002). There was no statically significant difference between the two groups regarding complication, vent days and ICU days. Conclusion Bedside US can be very useful in the evaluation and management of mechanically ventilated patients in ICUs and to guide the RM in ARDS patients. There is no significant difference between the sustained inflation RM and the sonar-guided stepwise PEEP titration RM regarding oxygenation and compliance except for the level of PEEP reached, which is lower in the stepwise PEEP titration group giving less potentiality for complications.

Performance of Dispersion-Inclusive Density Functional Theory Methods for Energetic Materials.

Molecular crystals of energetic materials (EMs) are denser than typical molecular crystals and are characterized by distinct intermolecular interactions between nitrogen-containing moieties. To assess the performance of dispersion-inclusive density functional theory (DFT) methods, we have compiled a data set of experimental sublimation enthalpies of 31 energetic materials. We evaluate the performance of three methods: the semilocal Perdew-Burke-Ernzerhof (PBE) functional coupled with the pairwise Tkatchenko-Scheffler (TS) dispersion correction, PBE with the many-body dispersion (MBD) method, and the PBE-based hybrid functional (PBE0) with MBD. Zero-point energy contributions and thermal effects are described using the quasi-harmonic approximation (QHA), including explicit treatment of thermal expansion, which we find to be non-negligible for EMs. The lattice energies obtained with PBE0+MBD are the closest to experimental sublimation enthalpies with a mean absolute error of 9.89 kJ/mol. However, the state-of-the-art treatment of vibrational and thermal contributions makes the agreement with experiment worse. Pressure-volume curves are also examined for six representative materials. For pressure-volume curves, all three methods provide reasonable agreement with experimental data with mean absolute relative errors of 3% or less. Most of the intermolecular interactions typical of EMs, namely nitro-amine, nitro-nitro, and nitro-hydrogen interactions, are more sensitive to the choice of the dispersion method than to the choice of the exchange-correlation functional. The exception is π-π stacking interactions, which are also very sensitive to the choice of the functional. Overall, we find that PBE+TS, PBE+MBD, and PBE0+MBD do not perform as well for energetic materials as previously reported for other classes of molecular crystals. This highlights the importance of testing dispersion-inclusive DFT methods for diverse classes of materials and the need for further method development.

Cardiac and Vascular Remodeling After 6 Months of Therapy With Sacubitril/Valsartan: Mechanistic Insights From Advanced Echocardiographic Analysis.

BackgroundEffects of Sacubitril/Valsartan (S/V) on left ventricular (LV) mechanics and ventricular-arterial coupling in patients with heart failure with reduced ejection fraction (HFrEF) are not completely understood. The aim of this study was to evaluate both cardiac and vascular remodeling in a group of HFrEF patients undergoing S/V therapy.MethodsFifty HFrEF patients eligible to start a therapy with S/V were enrolled. Echocardiographic evaluation was performed at baseline and after 6 months of follow-up (FU). Beside standard evaluation, including global longitudinal strain (GLS), estimated hemodynamic forces (HDFs) and non-invasive pressure-volume curves (PV loop) were assessed using dedicated softwares. HDFs were evaluated over the entire cardiac cycle, in systole and diastole, both in apex to base (A-B) and latero-septal (L-S) directions. The distribution of LV HDFs was evaluated by L-S over A-B HDFs ratio (L-S/A-B HDFs ratio). Parameters derived from estimated PV loop curves were left ventricular end-systolic elastance (Ees), arterial elastance (Ea), and ventricular-arterial coupling (VAC).ResultsAt 6 months of FU indexed left ventricular end-diastolic and end-systolic volumes decreased (EDVi: 101 ± 28 mL vs. 86 ± 30 mL, p < 0.001; ESVi: 72 ± 23 mL vs. 55 ± 24 mL, p < 0.001), ejection fraction and GLS significantly improved (EF: 29 ± 6% vs. 37 ± 7%, p < 0.001; GLS: −9 ± 3% vs. −13 ± 4%, p < 0.001). A reduction of Ea (2.11 ± 0.91 mmHg/mL vs. 1.72 ± 0.44 mmHg/mL, p = 0.008) and an improvement of Ees (1.01 ± 0.37 mmHg/mL vs. 1.35 ± 0.6 mmHg/mL, p < 0.001) and VAC (2.3 ± 1.1 vs. 1.5 ± 0.7, p < 0.001) were observed. Re-alignment of HDFs occurred, with a reduction of diastolic L-S/A-B HDFs ratio [23 (20–35)% vs. 20 (11–28) %, p < 0.001].ConclusionS/V therapy leads to a complex phenomenon of reverse remodeling involving increased myocardial contractility, HDFs distribution improvement, and afterload reduction.

GAA Deficiency Disrupts Distal Airway Cells in Pompe Disease

Pompe disease is an autosomal recessive glycogen storage disease caused by mutations in alpha‐glucosidase (GAA) ‐ an enzyme responsible of hydrolyzing lysosomal glycogen. GAA deficiency results in systemic lysosomal glycogen accumulation and cellular disruption. Skeletal muscle, motor neuron pathology and airway smooth muscle cells are known to contribute to respiratory insufficiency in Pompe disease, but the role of distal airway cells including alveolar type 1 and type 2 cells (AT1 and AT2, respectively) has not been evaluated. AT1 cells depend on lysosomes for cellular homeostasis to maintain a thin barrier for gas exchange whereas AT2 cells depend on lysosomal structures for surfactant production. Using an established mouse model of Pompe disease, the Gaa−/− mouse, we compared lung histology using Periodic acid‐Schiff staining, quantification of immunohistochemistry staining and electron microscopy, and pulmonary mechanics using forced oscillometry FlexiVent system, between Gaa−/− and age‐matched wild‐type (WT) mice. We also perfomed single cell‐RNA seq (scRNA‐seq) on the distal airways of Gaa‐/‐ mice. Lysosomal glycogen accumulation and engorged lamellar bodies were observed in the AT2 cells in Gaa−/− but not WT mice. Furthermore, AT2 positive surfactant protein‐C (SPC) staining and lysosomal positive lysosomal associated membrane protein 1 (LAMP1) staining is more evident with increased colocalization of LAMP1 with the type 2 cell marker after quantification of each marker in Gaa−/− airway cells. The Gaa−/− mice exhibited a significant decrease in total and central airway resistance (Rrs and Rn, respectively), as well as a significant increase in lung compliance (Crs) versus WT mice. Moreover, in the dimensionless and volume‐independent shape constant k that describes the curvature of the upper portion of the deflation limb of the Pressure‐Volume curves, a statistically significant change was observed in Gaa−/− mice. This indicates a change in the intrinsic elastic properties of the respiratory system in Pompe disease. Finally, a robust transcriptomic dysregulation in AT1 and AT2 cells was detected scRNA‐seq in Gaa‐/‐mice relative to WT mice. We conclude that GAA enzyme deficiency leads to glycogen accumulation in the distal airway stem cells that may contribute to respiratory impairments in Pompe disease. Our findings will inform the clinical care of patients with Pompe disease and will provide essential information for the development of novel therapies in Pompe disease that will address this airway pathology.

Genesis of Antibiotic Resistance (AR) LXXX: Turbulence Modeling(TM) of Hemodynamics in Simplified Severe Sepsis Protocol‐2 (SSSP‐2)‐NCT01663701: Temporal Correlation of Fluid Bolus, CPPopt(PRx), “Zone of Obstruction”, Comatose (GCS 3), and In‐Hospital Mortality (ihm)

Based on Flow‐3DÒ Hydro FD simulation Model 04 (Courtesy: Flow‐3DÒ) and fluid flow patterns, here we present a plausible scheme of hemodyn. sequel in ERP induced fluid volume expansion, that lead to 100% ihm usual care cohort of SSSP‐2 (PMID: 28973227). Rationale: From the pressure‐volume curve of D ICP vs DCBV (ΔV cm3) of the intracerebral space Figure1. https://cppopt.org/prx/ (PMID: 632857) it is proposed that subsequent to fluid bolus, the patients in usual care and sepsis protocol cohort of SSSP‐2 may have had a good compensatory reserve (part I) within&lt; 24hrs. The exponential part of the curve (part II) would likely represent the patients who have had a poor compensatory reserve with a slow ΔV of the intracerebral space (CBV) that caused a significant change in the ICP in less than ~48 hrs. The cause of 100% ihm in usual care cohort, could be derived as the patients with high CBV and consequently high ICP levels (part III)that lead to cerebral vessels collapse and impairing pressure‐volume relationship implied in impaired positive brain vessel function index possibly by capillary pruning‐string events within ~ 48hrs to ~72 hrs. An increase in CVP, lead to an anaerobic milieu to spur the growth of anaerobic AR‐ClPr (G+/G‐) bacilli merging with “Zone of Obstruction” (ZoO), hitherto DDx, CC/MCC/CCI/DRG, Comorbidity–polypharmacy score (CPS) and ultimately Comatose (GCS 3‐8) (PMID: 31474933). Hemodynamically, when there is an ÝABP/ CPP/CBV the arterioles dilate and hence the CBF, CBV and consequently the ÝICP. Geometry: (Table 2.1 p63, ISBN: 9780128024089). Hemodyn/neurol monitoring parameters:CPPopt, CVP ≥ 8 cm H20, ScVO2 ≤ 70%, GCS 3‐8, and time to event 120 hrs ± 48 hrs. Governing. Equation(s): Dimensional form of Momentum equation (9.10) at the wall u= v=0, considering the pressure gradient dp/dx&lt;0, then [d2u/dy2]y=0=1/μ *dp/dx Eq 9.42; Fig 9.5 Flow separation and formation of wake behind ZoO (LPE Aggregates ‐Toxins of AR‐ClPr origin) form blunt bodies/streamline bodies referred as “ZoO” of unknown dimension; Fig 9.6 velocity distribution within a boundary layer; considered panel a: favorable pressure gradient = dp/dx&lt;0; panel b: APG = dp/dx&gt;0 (p468 – 471; ISBN:13:978‐0071329194). Derivation &amp; Prospect: Subsequent to fluid bolus, within 120 hrs., BLS occurs expediting the ZoO, in metarteriole, capillary bed, and arteriovenous anastomosis doffing off vaso vasorum in turn vasomotion of the limbic region in particular cingulate nuclei, Amygdala, amygdaloid body, thalamic nuclei, parahippocampal gyrus, hypothalamus. Such an increase in CPPopt, and CBV engendered APG, eddies, ZoO, in cerebral pre‐capillary bed followed by a vasoconstriction of capillary sphincters, the collapse of arteriovenous anastomosis, possible occlusion of thoroughfare channel in true capillaries form a cyclical aerobic‐anaerobic milieu in vivo (en vivo) for the growth G+/G‐ AR‐ClPr, in turn spur toxic shock syndrome, CCP to GCS 3 consequential 100% ihm, within 120 hrs. in SSSP‐2.

Equal compressibility structural phase transition of molybdenum at high pressure

We have studied the high-pressure compression behavior of molybdenum up to 60 GPa by synchrotron radial x-ray diffraction (RXRD) in a diamond anvil cell (DAC). It is found that all diffraction peaks of molybdenum undergo a split at around 27 GPa, and we believe that a phase transition from a body-centered cubic structure to a rhombohedral structure at room pressure has occurred. The slope of pressure–volume curve shows continuity before and after this phase transition, when fitting the pressure–volume curves of the body-centered cubic structure at low pressure and the rhombohedral structure at high pressure. A bulk modulus of 261.3 (2.7) GPa and a first-order derivative of the bulk modulus of 4.15 (0.14) are obtained by using the nonhydrostatic compression data at the angle ψ = 54.7° between the diffracting plane normal and stress axis.

Drought-related leaf functional traits control spatial and temporal dynamics of live fuel moisture content

Large forest fires generally occur when the moisture content of fuels is low. For live fuels, our understanding of the physiological basis of variation in moisture content has recently advanced. However, process-based models of live fuel moisture content (LFMC) remain elusive. Here, we aim to further our understanding of the role of physiological mechanisms and plant functional traits in driving spatiotemporal variations in LFMC. We examined whether temporal variation in LFMC could be predicted from pressure-volume curve data, which measures leaf water potential and water content on cut shoots dehydrating on a bench. We also examined whether leaf dry mass traits could predict spatial variation in maximum LFMC. We undertook our study in eucalypt forests and woodlands spanning a large climatic gradient in eastern Australia. We found that LFMC models developed from pressure-volume curves reliably predicted seasonal variation in LFMC across four co-occurring species. A two-phase LFMC model, which fit models above and below the turgor loss point (mean absolute error = 3.7-33.2%), performed similarly well to a simple linear model (mean absolute error = 3.4-35.3%). Across a large climatic gradient, the maximum LFMC of 16 species was correlated with specific leaf area (R2 = 0.54), with the exception of one species with terete terminal stems. Maximum LFMC was highly correlated with aridity (R2 = 0.82), with lower LFMC observed in more arid sites. Our study demonstrates that spatiotemporal dynamics of LFMC are governed by both leaf dry mass traits and the relationship between leaf water potential and water content, which in turn is determined by traits such as cell wall elasticity. Thus, incorporating these traits into models of LFMC, whether these models are based on drought indices, soil moisture, or remotely sensed imagery, is likely to improve overall model performance, and subsequently improve forecasts of wildfire danger.

Development of the PhysioVessel: a customizable platform for simulating physiological fluid resuscitation

Uncontrolled hemorrhage is a leading cause of death in trauma situations. Developing solutions to automate hemorrhagic shock resuscitation may improve the outcomes for trauma patients. However, testing and development of automated solutions to address critical care interventions, oftentimes require extensive large animal studies for even initial troubleshooting. The use of accurate laboratory or in-silico models may provide a way to reduce the need for large animal datasets. Here, a tabletop model, for use in the development of fluid resuscitation with physiologically relevant pressure-volume responsiveness for high throughput testing, is presented. The design approach shown can be applied to any pressure-volume dataset through a process of curve-fitting, 3D modeling, and fabrication of a fluid reservoir shaped to the precise curve fit. Two case studies are presented here based on different resuscitation fluids: whole blood and crystalloid resuscitation. Both scenarios were derived from data acquired during porcine hemorrhage studies, used a pressure-volume curve to design and fabricate a 3D model, and evaluated to show that the test platform mimics the physiological data. The vessels produced based on data collected from pigs infused with whole blood and crystalloid were able to reproduce normalized pressure-volume curves within one standard deviation of the porcine data with mean residual differences of 0.018 and 0.016, respectively. This design process is useful for developing closed-loop algorithms for resuscitation and can simplify initial testing of technologies for this life-saving medical intervention.

Dynamic and Static Cardiac Function Measurements During Sepsis.

Dynamic and Static Cardiac Function Measurements During Sepsis.

Estimation of Regional Pulmonary Compliance in Idiopathic Pulmonary Fibrosis Based on Personalized Lung Poromechanical Modeling.

Pulmonary function is tightly linked to the lung mechanical behavior, especially large deformation during breathing. Interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF), have an impact on the pulmonary mechanics and consequently alter lung function. However, IPF remains poorly understood, poorly diagnosed, and poorly treated. Currently, the mechanical impact of such diseases is assessed by pressure-volume curves, giving only global information. We developed a poromechanical model of the lung that can be personalized to a patient based on routine clinical data. The personalization pipeline uses clinical data, mainly computed tomography (CT) images at two time steps and involves the formulation of an inverse problem to estimate regional compliances. The estimation problem can be formulated both in terms of "effective", i.e., without considering the mixture porosity, or "rescaled," i.e., where the first-order effect of the porosity has been taken into account, compliances. Regional compliances are estimated for one control subject and three IPF patients, allowing to quantify the IPF-induced tissue stiffening. This personalized model could be used in the clinic as an objective and quantitative tool for IPF diagnosis.

The Heat Shock Protein 90 Inhibitor, AT13387, Protects the Alveolo-Capillary Barrier and Prevents HCl-Induced Chronic Lung Injury and Pulmonary Fibrosis.

Hydrochloric acid (HCl) exposure causes asthma-like conditions, reactive airways dysfunction syndrome, and pulmonary fibrosis. Heat Shock Protein 90 (HSP90) is a molecular chaperone that regulates multiple cellular processes. HSP90 inhibitors are undergoing clinical trials for cancer and are also being studied in various pre-clinical settings for their anti-inflammatory and anti-fibrotic effects. Here we investigated the ability of the heat shock protein 90 (HSP90) inhibitor AT13387 to prevent chronic lung injury induced by exposure to HCl in vivo and its protective role in the endothelial barrier in vitro. We instilled C57Bl/6J mice with 0.1N HCl (2 µL/g body weight, intratracheally) and after 24 h began treatment with vehicle or AT13387 (10 or 15 mg/kg, SC), administered 3×/week; we analyzed histological, functional, and molecular markers 30 days after HCl. In addition, we monitored transendothelial electrical resistance (TER) and protein expression in a monolayer of human lung microvascular endothelial cells (HLMVEC) exposed to HCl (0.02 N) and treated with vehicle or AT13387 (2 µM). HCl provoked persistent alveolar inflammation; activation of profibrotic pathways (MAPK/ERK, HSP90); increased deposition of collagen, fibronectin and elastin; histological evidence of fibrosis; and a decline in lung function reflected in a downward shift in pressure–volume curves, increased respiratory system resistance (Rrs), elastance (Ers), tissue damping (G), and hyperresponsiveness to methacholine. Treatment with 15 mg/kg AT13387reduced alveolar inflammation, fibrosis, and NLRP3 staining; blocked activation of ERK and HSP90; and attenuated the deposition of collagen and the development of chronic lung injury and airway hyperreactivity. In vitro, AT13387 prevented HCl-induced loss of barrier function and AKT, ERK, and ROCK1 activation, and restored HSP70 and cofilin expression. The HSP90 inhibitor, AT13387, represents a promising drug candidate for chronic lung injury that can be administered subcutaneously in the field, and at low, non-toxic doses.