Outflow Parameters Research Articles

X-Ray Winds in Nearby-to-distant Galaxies (X-WING). I. Legacy Surveys of Galaxies with Ultrafast Outflows and Warm Absorbers in z ∼ 0–4

As an inaugural investigation under the X-ray Winds In Nearby-to-distant Galaxies (X-WING) program, we assembled a data set comprising 132 active galactic nuclei (AGNs) spanning redshifts z ∼ 0–4 characterized by blueshifted absorption lines indicative of X-ray winds. Through an exhaustive review of previous research, we compiled the outflow parameters for 583 X-ray winds, encompassing key attributes such as outflow velocities (V out), ionization parameters (ξ), and hydrogen column densities. By leveraging the parameters V out and ξ, we systematically categorized the winds into three distinct groups: ultrafast outflows (UFOs), low-ionization parameter (low-IP) UFOs, and warm absorbers (WAs). Strikingly, a discernible absence of linear correlations in the outflow parameters, coupled with distributions approaching instrumental detection limits, was observed. Another notable finding was the identification of a velocity gap around V out ∼ 10,000 km s−1. This gap was particularly evident in the winds detected via absorption lines within the ≲2 keV band, indicating disparate origins for low-IP UFOs and WAs. In cases involving Fe xxv/Fe xxvi lines, where the gap might be attributed to potential confusion between emission/absorption lines and the Fe K-edge, the possibility of UFOs and galactic-scale WAs being disconnected is considered. An examination of the outflow and dust sublimation radii revealed a distinction: UFOs appear to consist of dust-free material, whereas WAs likely comprise dusty gas. From 2024, the X-Ray Imaging and Spectroscopy Mission is poised to alleviate observational biases, providing insights into the authenticity of the identified gap, a pivotal question in comprehending AGN feedback from UFOs.

The impact of diabetes mellitus on foot perfusion measured by ICG NIR fluorescence imaging

IntroductionDiabetes Mellitus (DM) is a common chronic disease, affecting 435 million people globally. Impaired vasculature in DM patients leads to complications like lower extremity arterial disease (LEAD) and foot ulcers, often resulting in amputations. DM causes additional peripheral neuropathy leading to multifactorial wound problems. Current diagnostics often deem unreliable, but Near-Infrared Fluorescence with Indocyanine Green (ICG NIR) can be used to assess the foot perfusion. Therefore, this study explores DM’s impact on foot perfusion using ICG NIR. MethodsBaseline ICG NIR fluorescence imaging was performed in LEAD patients with and without DM. Ten perfusion parameters were extracted and analyzed to assess differences in perfusion patterns. ResultsAmong 109 patients (122 limbs) of the included patients, 32.8 % had DM. Six of ten perfusion parameters, mainly inflow-related, differed significantly between DM and non-DM patients (p-values 0.007–0.039). Fontaine stage 4 DM patients had the highest in- and outflow values, with seven parameters significantly higher (p-values 0.004–0.035). ConclusionDM is associated with increased in- and outflow parameters. Patients with- and without DM should not be compared directly due to different vascular pathophysiology and multifactorial wound problems in DM patients. Quantified ICG NIR fluorescence imaging offers additional insight into the effect of DM on foot perfusion.

Understanding the radio luminosity function of star-forming galaxies and its cosmological evolution

ABSTRACT We explore the redshift evolution of the radio luminosity function (RLF) of star-forming galaxies using galform, a semi-analytic model of galaxy formation and a dynamo model of the magnetic field evolving in a galaxy. Assuming energy equipartition between the magnetic field and cosmic rays, we derive the synchrotron luminosity of each sample galaxy. In a model where the turbulent speed is correlated with the star formation rate, the RLF is in fair agreement with observations in the redshift range 0 ≤ z ≤ 2. At larger redshifts, the structure of galaxies, their interstellar matter, and turbulence appear to be rather different from those at z ≲ 2, so that the turbulence and magnetic field models applicable at low redshifts become inadequate. The strong redshift evolution of the RLF at 0 ≤ z ≤ 2 can be attributed to an increased number, at high redshift, of galaxies with large disc volumes and strong magnetic fields. On the other hand, in models where the turbulent speed is a constant or an explicit function of z, the observed redshift evolution of the RLF is poorly captured. The evolution of the interstellar turbulence and outflow parameters appear to be major (but not the only) drivers of the RLF changes. We find that both the small- and large-scale magnetic fields contribute to the RLF but the small-scale field dominates at high redshifts. Polarization observations will therefore be important to distinguish these two components and understand better the evolution of galaxies and their non-thermal constituents.

Evaluation of associations between outflow morphology and rupture risk of abdominal aortic aneurysms

PurposeThis study aimed to evaluate the association between the outflow morphology and abdominal aortic aneurysm (AAA) rupture risk, to find risk factors for future prediction models. Materials and methodsWe retrospectively analyzed 46 patients with ruptured AAAs and 46 patients with stable AAAs using a 1:1 match for sex, age, and maximum aneurysm diameter. The chi-square test, paired t-test, and Wilcoxon signed-rank test were used to compare variables. Logistic regression was performed to evaluate variables potentially associated with AAA rupture. Receiver operating characteristic curve analysis and the area under the curve (AUC) were used to assess the regression models. ResultsRuptured AAAs had a shorter proximal aortic neck (median (interquartile range, IQR): 24.0 (9.4–34.2) mm vs. 33.3 (20.0–52.8) mm, p = 0.004), higher tortuosity (median(IQR): 1.35 (1.23–1.49) vs. 1.29 (1.23–1.39), p = 0.036), and smaller minimum luminal area of the right common iliac artery (CIA) (median (IQR): 86.7 (69.9–126.4) mm2 vs. 118.9 (86.3–164.1)mm2, p = 0.001) and left CIA (median(IQR): 92.2 (67.3,125.1) mm2 vs. 110.7 (80.12, 161.1) mm2, p = 0.010) than stable AAA did. Multiple regression analysis demonstrated significant associations of the minimum luminal area of the bilateral CIAs (odds ratio [OR] = 0.996, 95 % confidence interval [CI] 0.991–0.999, p = 0.037), neck length (OR = 0.969, 95 % CI 0.941–0.993, p = 0.017), and aneurysm tortuosity (OR = 1.031, 95 % CI 1.003–1.063, p = 0.038) with ruptured AAAs. The AUC of this regression model was 0.762 (95 % CI 0.664–0.860, p < 0.001). ConclusionsThe smaller minimum luminal area of the CIA is associated with an increased risk of rupture. This study highlights the potential of utilizing outflow parameters as novel and additional tools in risk assessment. It also provides a compelling rationale to further intensify research in this area.

On the Transition from Efficient to Inefficient Line Driving in Irradiated Flows

Observations of ionized outflows from active galactic nuclei (AGNs) provide evidence of energy and momentum transfer from the AGN radiation to the plasma. The AGN radiation is very energetic. Therefore, at distances of parsec scale, where gravity is relatively weak, energy transfer alone can lead to outflow. Much closer to the black hole, gravity dominates thermal energy and the gas is in the so-called “cold” regime. Only magnetic or radiation forces can lead to outflow. However, it is unclear when the radiation force is efficient in overcoming gravity because of its dependence on the spectral energy distribution (SED) of the radiation and opacity. In this work, we survey the parameter space of radiation forces due to spectral lines resulting from blackbody SEDs with temperatures ranging from ∼104 to 106 K. The objective was to identify the radiation temperature above which line driving becomes inefficient. We find that the temperature ≲4 × 105 K marks such a transition. We also self-consistently calculate heating and cooling balance to estimate gas temperature and identify the transition where thermal driving becomes comparable to line driving. We summarize hydrodynamical simulations of radial outflows to illustrate how wind properties change during the transition from line to thermal driving and their dependence on outflow parameters and SED.

Early Flood Monitoring and Forecasting System Using a Hybrid Machine Learning-Based Approach

The occurrence of flash floods in urban catchments within the Mediterranean climate zone has witnessed a substantial rise due to climate change, underscoring the urgent need for early-warning systems. This paper examines the implementation of an early flood monitoring and forecasting system (EMFS) to predict the critical overflow level of a small urban stream on Lesvos Island, Greece, which has a history of severe flash flood incidents requiring rapid response. The system is supported by a network of telemetric stations that measure meteorological and hydrometric parameters in real time, with a time step accuracy of 15 min. The collected data are fed into the physical Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS), which simulates the stream’s discharge. Considering the HEC-HMS’s estimated outflow and other hydro-meteorological parameters, the EMFS uses long short-term memory (LSTM) neural networks to enhance the accuracy of flood prediction. In particular, LSTMs are employed to analyze the real-time data from the telemetric stations and make multi-step predictions of the critical water level. Hydrological time series data are utilized to train and validate the LSTM models for short-term leading times of 15 min, 30 min, 45 min, and 1 h. By combining the predictions obtained by the HEC-HMS with those of the LSTMs, the EMFS can produce accurate flood forecasts. The results indicate that the proposed methodology yields trustworthy behavior in enhancing the overall resilience of the area against flash floods.

Synchronous Superficial Middle Cerebral Vein Outflow Correlates Favorable Tissue Fate After Mechanical Thrombectomy for Acute Ischemic Stroke

The purpose of this study was to determine the association between hemispheric synchrony in venous outflow at baseline and tissue fate after mechanical thrombectomy (MT) for acute ischemic stroke (AIS). A two-center retrospective analysis involving AIS patients who underwent MT was performed. The four cortical veins of interest include the superficial middle cerebral vein (SMCV), sphenoparietal sinus (SS), vein of Labbé (VOL), and vein of Trolard (VOT). Baseline computed tomography perfusion data were used to compare the following outflow parameters between the hemispheres: first filling time (△FFT), time to peak (△TTP) and total filling time (△TFT). Synchronous venous outflow was defined as △FFT=0. Multivariable regression analyses were performed to evaluate the association of venous outflow synchrony with penumbral salvage, infarct growth, and intracranial hemorrhage (ICH) after MT. A total of 151 patients (71.4±13.2 years, 65.6% women) were evaluated. Patients with synchronous SMCV outflow demonstrated significantly greater penumbral salvage (41.3 mL vs. 33.1 mL, P=0.005) and lower infarct growth (9.0 mL vs. 14.4 mL, P=0.015) compared to those with delayed SMCV outflow. Higher △FFTSMCV (β=-1.44, P=0.013) and △TTPSMCV (β=-0.996, P=0.003) significantly associated with lower penumbral salvage, while higher △FFTSMCV significantly associated with larger infarct growth (β=1.09, P=0.005) and increased risk of ICH (odds ratio [OR]=1.519, P=0.047). Synchronous SMCV outflow is an independent predictor of favorable tissue outcome and low ICH risk, and thereby carries the potential as an auxiliary radiological marker aiding the treatment planning of AIS patients.

A Review of the Electrical Submersible Pump Development Chronology

The electric submersible pump, also known as ESP, is a highly effective artificial lift method widely used in the oil industry due to its ability to deliver higher production rates compared to other artificial lift methods. In principle, ESP is a multistage centrifugal pump that converts kinetic energy into dynamic hydraulic pressure necessary to lift fluids at a higher rate with lower bottomhole pressure, especially in oil wells under certain bottomhole condition fluid, and reservoir characteristics. However, several factors and challenges can complicate the completion and optimum development of ESP deployed wells, which need to be addressed to optimize its performance by maximizing efficiency and minimizing costs and uncertainties. To analyze the performance of ESP deployed wells, the objective function must include various factors associated with fluids, reservoir inflow and outflow characteristics, and pump parameters. In particular, the inflow and outflow parameters include well configuration, and types of completion string (e.g. tubing sizes, and download completion hardware) while reservoir and fluid parameters include pressure, temperature, and PVT properties. Pump parameters include gas vacuum fraction, electrical and mechanical constraints, power requirements, cable requirements, downhole conditions, etc. Despite these challenges, ESPs' importance and efficiency necessitate an in-depth understanding of its origins and evolution over time, as well as the difficulties encountered in the oil industry. This paper aims to provide a comprehensive review of ESP's origin and development, including all prior studies that have influenced optimum development. The literature review is divided into four main sections: experimental investigations, numerical simulation studies, mechanical modeling, and in-depth studies on production optimization. By providing an in-depth analysis of previous work in each area, this paper aims to contribute to ongoing efforts to enhance ESPs' performance and efficiency in the oil industry.

RIGHT VENTRICULAR FUNCTION IN ARTERIAL HYPERTENSION (M-MODE ECHOCG STUDY)

Objective: Until recently Researchers underestimated right ventricular (RV) physiological and described it as passive conduit with a little pumping capability which just connects right atrium (RA) with pulmonary artery. Over the last decades, numerous studies have demonstrated the physiological and clinical importance of RV function. Contrary to the LV, the RV has much complex geometry. It consists of an inlet, outlet, and apical trabecular portion which are different structurally and functionally. There is no information about Right ventricular outflow structure and function in patients with Arterial Hypertension (AH). The aim of the research was to study the changes of RV Outflow and Inflow functional parameters in patients with Arterial Hypertension. Design and method: We studied 214 patients AH (male-115, fem-99, mean age 55.6±12.2, mean arterial pressure – systolic 174.1±15.2, diastolic 96.8±11.2). Control group consist from 180 normal persons (male-88, fem-92, mean age 49.7±12.2, mean arterial pressure – systolic 122.1±12.2, diastolic 71.8±10.2). All participants undergone standard EchoCG examination. Two-dimensional echocardiograms of the parasternal short axis view at the level of the aortic root were obtained for the RVOT sizes and fractional shortening (RVOT-FS) values. M-mode recordings of the RVOT were obtained and dimensions were measured at end -diastole and end systole. RV outflow Fractional Shortening (RVoutFS%, calculated with formula (RVoutDiastD-RVoutSystD)/RVoutDiastD%). Results: 12 patients had stage-1 AH, 138- stage 2 and 64 stage 3 AH. In AH group RV wall thickness (4.2±0.9 mm versus 3.5±0.7mm), RV outflow tract systolic and diastolic diameters (32.8±4.8mm and 14.7±3.2mm versus 30.8±4.7 and 13.2±2.8mm) where greater and RVoutFS% (55.1±4.8% versus 58.8±4.3%) Pulmonary flow acceleration time (121.6±17.1versus 132.6±12.2 msec) lesser then in control. On the other hand, there was no difference in TAPSE between the groups. Conclusions: Despite any differences in RV inflow function There are prominent changes in RV outflow tract function and structure in patients with AH. RVoutFS% is a marker of early functional changes of RV in patients with AH

Perfusion assessment by fluorescence time curves in esophagectomy with gastric conduit reconstruction: a prospective clinical study

BackgroundIntraoperative perfusion assessment with indocyanine green fluorescence angiography (ICG-FA) may reduce postoperative anastomotic leakage rates after esophagectomy with gastric conduit reconstruction. This study evaluated quantitative parameters derived from fluorescence time curves to determine a threshold for adequate perfusion and predict postoperative anastomotic complications.MethodsThis prospective cohort study included consecutive patients who underwent FA-guided esophagectomy with gastric conduit reconstruction between August 2020 and February 2022. After intravenous bolus injection of 0.05-mg/kg ICG, fluorescence intensity was registered over time by PINPOINT camera (Stryker, USA). Fluorescent angiograms were quantitatively analyzed at a region of interest of 1 cm diameter at the anastomotic site on the conduit using tailor-made software. Extracted fluorescence parameters were both inflow (T0, Tmax, Fmax, slope, Time-to-peak) as outflow parameters (T90% and T80%). Anastomotic complications including anastomotic leakage (AL) and strictures were documented. Fluorescence parameters in patients with AL were compared to those without AL.ResultsOne hundred and three patients (81 male, 65.7 ± 9.9 years) were included, the majority of whom (88%) underwent an Ivor Lewis procedure. AL occurred in 19% of patients (n = 20/103). Both time to peak as Tmax were significantly longer for the AL group in comparison to the non-AL group (39 s vs. 26 s, p = 0.04 and 65 vs. 51 s, p = 0.03, respectively). Slope was 1.0 (IQR 0.3–2.5) and 1.7 (IQR 1.0–3.0) for the AL and non-AL group (p = 0.11). Outflow was longer in the AL group, although not significantly, T90% 30 versus 15 s, respectively, p = 0.20). Univariate analysis indicated that Tmax might be predictive for AL, although not reaching significance (p = 0.10, area under the curve 0.71) and a cut-off value of 97 s was derived, with a specificity of 92%.ConclusionThis study demonstrated quantitative parameters and identified a fluorescent threshold which could be used for intraoperative decision-making and to identify high-risk patients for anastomotic leakage during esophagectomy with gastric conduit reconstruction.A significant predictive value remains to be determined in future studies.

Search for Solar Sources of Interplanetary Coronal Mass Ejections Using the Reverse Model of Magnetodynamic Interaction of the Solar Wind in the Heliosphere

In the development and testing of methods for predicting interplanetary coronal mass ejections (ICMEs), it is important to establish their relationship with sources on the Sun—coronal mass ejections (CMEs) observed by coronagraphs. The often used inverse ballistic calculation of the CME onset time does not consider variations in the CME speed when moving through the heliosphere and can give an uncertainty up to a day. With a good accuracy (on the order of ±10 h), the propagation of CMEs in the heliosphere from the Sun to the Earth is described by the model of the magnetodynamic interaction of CMEs with the background solar wind (drag-based model, DBM). In this paper, we propose to search for possible coronal sources of ICMEs, observed near the Earth, using the reverse model of magnetodynamic interaction (reverse DBM, RDBM), which reconstructs in the reverse course the probable propagation of CMEs in the heliosphere and determines their outflow parameters in the solar corona using the measured ICME parameters. The model uses the speed of the background solar wind, which is calculated from the area of coronal holes in the central part of the Sun and presented on the website of the Space Monitoring Data Center of the Skobeltsyn Institute of Nuclear Physics, Moscow State University (SINP MSU), with correction factors.

Impaired glymphatic drainage underlying obstructive sleep apnea is associated with cognitive dysfunction

Obstructive sleep apnea (OSA) is highly prevalent but easily undiagnosed and is an independent risk factor for cognitive impairment. However, it remains unclear how OSA is linked to cognitive impairment. In the present study, we found the correlation between morphological changes of perivascular spaces (PVSs) and cognitive impairment in OSA patients. Moreover, we developed a novel set of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) methods to evaluate the fluid dynamics of glymphatic drainage system. We found that the inflow and outflow parameters of the glymphatic drainage system in patients with OSA were obviously changed, indicating impairment of glymphatic drainage due to excessive perfusion accompanied with deficient drainage in OSA patients. Moreover, parameters of the outflow were associated with the degree of cognitive impairment, as well as the hypoxia level. In addition, continuous positive airway pressure (CPAP) enhances performance of the glymphatic drainage system after 1 month treatment in OSA patients. We proposed that ventilation improvement might be a new strategy to ameliorate the impaired drainage of glymphatic drainage system due to OSA-induced chronic intermittent hypoxia, and consequently improved the cognitive decline.

A NuSTAR view of SS433

Context. SS433 is a Galactic microquasar with powerful outflows (double jet, accretion disk and winds) with a well-known orbital, precessional, and nutational period. Aims. In this work we characterise different outflow parameters throughout the precessional cycle of the system. Methods. We analysed ten NuSTAR (3–70 keV) observations of ∼30 ks that span ∼1.5 precessional cycles. We extracted averaged spectra and modelled them using a combination of a double thermal jet model (bjet) and pure neutral and relativistic reflection (xillverCp and relxilllpCp) over an accretion disk. Results. We find an average jet bulk velocity of β = v/c ∼ 0.29 with an opening angle of ≲6 deg. Eastern jet kinetic power ranges from 1 to 1039 erg s−1, with base ‘coronal’ temperatures To ranging from between 14 and 18 keV. Nickel-to-iron abundances remain constant at ∼9 (within 1σ). The western to eastern jet-flux ratio becomes ∼1 on intermediate phases, which is about 35% of the total precessional orbit. The 3–70 keV total unabsorbed luminosity of the jet and disk ranges from 2 to 20 × 1037 erg s−1, with the disk reflection component mainly contributing to the hard 20–30 keV excess and the stationary 6.7 keV ionised Fe line complex. Conclusions. At low opening angles Θ, we find that the jet expands sideways following an adiabatic expansion of a gas with temperature To. Finally, the central source and lower parts of the jet could be hidden by an optically thick region of τ &gt; 0.1 and size R ∼ NH/ne0 ∼ 1.5 × 109 cm ∼ 1700 rg for MBH = 3 M⊙.

Экспериментально-аналитические исследования критических условий факельного горения газов и паров криогенных топлив

The need to organize emissions of a large amount of gas arises in a number of technological operations related to the transportation, storage and processing of combustible gases, preparation and purging of containers, etc. The largest emissions occur during emergencies. For a correct assessment of the level of fire hazard and the choice of efficient ways to prevent fires, it is required to study in detail many defining parameters. First of all these are the limiting conditions for stabilization and extinguishing of diffusion flame of the torch. An analysis was made of the formation and stabilization conditions of a diffusion torch formed during the outflow of combustible gas from various gas discharge devices. On the basis of theoretical studies based on a single physical model, analytical expressions are derived. They describe the limiting conditions for the stabilization of turbulent diffusion torches in a wide range of changes in gas outflow conditions and parameters of the surrounding atmosphere. The proposed dependences allow to evaluate the complex effect of various factors (gas composition, gas discharge velocity and direction, size and shape of vents, wind speed, oxygen concentration in the surrounding space) on the parameters of turbulent diffusion torches. Within the framework of the study, the experimental regularities of stabilization and gas-dynamic extinguishing of turbulent diffusion torches are determined. These regularities make it possible to evaluate the influence of various factors (the degree of dilution of the combustible gas with an inert gas, the size and shape of the discharge hole, wind speed and oxygen concentration in the surrounding space) on the limiting conditions for stabilization of diffusion torches.

The first look at narrow-line Seyfert 1 galaxies with eROSITA

We present the first look at the spectral and timing analysis of narrow-line Seyfert 1 galaxies (NLS1s) with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spectrum-Roentgen-Gamma (SRG) mission. The sample of approximately 1200 NLS1s was obtained via a cross-match between the first eROSITA All-Sky Survey (eRASS1) catalogue and the catalogue of spectroscopically selected NLS1s from the twelfth data release of the Sloan Digital Sky Survey (SDSS) DR12. The X-ray spectral analysis is based on a simple power-law fit. The photon index distribution has a mean value of about 2.81 ± 0.03, as expected from previous X-ray studies of NLS1s. Interestingly, it is positively skewed, and about 10% of the sources are located in the super-soft tail of photon indices larger than 4. These sources are of further interest as their source counts run into the X-ray background at values at around 1 keV. We argue that ionised outflows have been detected by eROSITA and may account for some of the extreme spectral steepness, which is supported by correlations found between the photon index and optical outflow parameters. We analysed the intrinsic X-ray variability of the eRASS1 to eRASS3 light curves of the sample but do not find significant variability either during the individual survey scans or between them.

Prompt Emission and Early Optical Afterglow of Very-high-energy Detected GRB 201015A and GRB 201216C: Onset of the External Forward Shock

We present a detailed prompt emission and early optical afterglow analysis of the two very-high-energy (VHE) detected bursts GRB 201015A and GRB 201216C, and their comparison with a subset of similar bursts. Time-resolved spectral analysis of multistructured GRB 201216C using the Bayesian binning algorithm revealed that during the entire duration of the burst, the low-energy spectral index (α pt) remained below the limit of the synchrotron line of death. However, statistically some of the bins supported the additional thermal component. Additionally, the evolution of spectral parameters showed that both the peak energy (E p) and α pt tracked the flux. These results were further strengthened using the values of the physical parameters obtained by synchrotron modeling of the data. Our earliest optical observations of both bursts using the F/Photometric Robotic Atmospheric Monitor Observatorio del Roque de los Muchachos and Burst Observer and Optical Transient Exploring System robotic telescopes displayed a smooth bump in their early optical light curves, consistent with the onset of the afterglow due to synchrotron emission from an external forward shock. Using the observed optical peak, we constrained the initial bulk Lorentz factors of GRB 201015A and GRB 201216C to Γ0 = 204 and Γ0 = 310, respectively. The present early optical observations are the earliest known observations constraining outflow parameters and our analysis indicate that VHE detected bursts could have a diverse range of observed luminosity within the detectable redshift range of present VHE facilities.

Delayed CTP-Derived Deep Venous Outflow: A Novel Predictor of Striatocapsular Infarction after M1 Thrombectomy.

Isolated striatocapsular infarction occurs commonly in patients with ischemic stroke following M1 thrombectomy. We aimed to explore the correlation between CTP-derived parameters of deep venous outflow at presentation and subsequent striatocapsular infarction in a retrospective cohort of such patients. TTP and peak enhancement were measured on CTP-derived time-attenuation curves of the internal cerebral and thalamostriate veins bilaterally. The difference in TTP (ΔTTP) and the relative decrease in venous enhancement between the ischemic and normal sides were calculated. NCCT performed 24 (SD, 12) hours postthrombectomy was used to determine tissue fate in the caudate head, caudate body, lentiform nucleus, and internal capsule. Striatocapsular ischemia (striatocapsular infarction-positive) was defined as infarction and striatocapsular injury as either infarction, contrast enhancement, or hemorrhagic transformation in ≥1 of these regions. A striatocapsular ischemia score was calculated (0 = no ischemic region, 1 = 1 ischemic region, 2 = ≥2 ischemic regions). One hundred sixteen patients were included in the analysis. Sixty-one patients had striatocapsular infarction (striatocapsular infarction-positive). The mean thalamostriate ΔTTP was 1.95 (SD, 1.9) seconds for patients positive for striatocapsular infarction and 0.79 (SD, 2.1) for patients negative for it (P = .010). Results were similar for striatocapsular injury. The mean thalamostriate ΔTTP was 0.79 (SD, 2.1), 1.68 (SD, 1.4), and 2.05 (SD, 2) for striatocapsular infarction scores of 0, 1, and 2, respectively (P = .030). CTP-derived thalamostriate ΔTTP is an excellent surrogate marker for striatocapsular infarction in patients post-M1 thrombectomy. The novel approach of extracting venous outflow parameters from CTP has numerous potential applications and should be further explored.

Catastrophic Cooling in Superwinds. III. Nonequilibrium Photoionization

Observations of some starburst-driven galactic superwinds suggest that strong radiative cooling could play a key role in the nature of feedback and the formation of stars and molecular gas in star-forming galaxies. These catastrophically cooling superwinds are not adequately described by adiabatic fluid models, but they can be reproduced by incorporating nonequilibrium radiative cooling functions into the fluid model. In this work, we have employed the atomic and cooling module maihem implemented in the framework of the flash hydrodynamics code to simulate the formation of radiatively cooling superwinds as well as their corresponding nonequilibrium ionization (NEI) states for various outflow parameters, gas metallicities, and ambient densities. We employ the photoionization program cloudy to predict radiation- and density-bounded photoionization for these radiatively cooling superwinds, and we predict UV and optical line emission. Our nonequilibrium photoionization models built with the NEI states demonstrate the enhancement of C iv, especially in metal-rich, catastrophically cooling outflows, and O vi in metal-poor ones.

312.9: Mathematical Modelling to Determine Segment Perfusion Parameters for Living Donor Liver Transplantation

Introduction: Adult-to-Adult Living Donor Liver Transplantation (A2ALL-1) Cohort Study focused on hepatic blood flow and effect of portal modulation in smaller and left lobe grafts demonstrating a significantly (p = 0.03) higher graft dysfunction in modulated recipients versus unmodulated. The study concluded the need for prespecified portal flow and hepatic venous outflow modulation protocols to better define outcomes of volumetric interventions. We developed a mathematical model of the liver to determine hemodynamic parameters across segments following simulated liver resections and middle hepatic vein interventions in both the remnant donor liver and recipient grafts to predict functional graft outcomes prior to reperfusion. Methods: Arterial/portal/hepatic vein and terminal portal triad diameters from 12 deceased donor livers and biopsies were used in a custom lumped parameter model developed in MATLAB {Fig(a)}. Blood flow is modeled using the Hagen-Poiseuille equation, and the continuity equation is solved to obtain volume flow rate of the whole liver at every point throughout the network {Fig(b)}. Simulated right hepatectomy in the plane of resection shown in Fig(a) is used to derive variations in blood flow and volume through the modeled left liver lobe {Fig(c)}.Results: Schematic illustrations of the modeling components of liver segments demonstrate volume flow rate encoded in pseudocolor mapping in the donor liver before and after right hepatectomy {Fig(b&c)}. Localized increase in blood flow through 2nd and 3rd generations of vessel division is especially apparent in the donor’s simulated remnant left lobe {Fig(c)}. Volume and flow rate alterations in hepatic venous outflow following ligation/reconstruction of middle hepatic veins in the remnant left lobe is evident. Perfusion parameters in the donor graft are also captured to simulate graft perfusion prior to reperfusion in the recipient. Conclusion: Surgical intervention on the middle hepatic vein (MHV) is critical for donor remnant liver outflow and optimal perfusion in the donor graft. Mathematical simulations to predict hemodynamic inflow – outflow parameters in living donor liver transplantation could help guide MHV ligation and reconstruction as well as predict graft perfusion parameters prior to reperfusion.

On the numerical modelling of astrospheres, including those of luminous blue variable stars, and the modulation of cosmic rays within

ABSTRACT Luminous blue variable-type stars are massive O-type stars that show variable outflow parameters. These stars can also undergo eruptions where a large amount of mass is ejected in a very short duration. The astrospheres of these stars are modelled using a magnetohydrodynamic model including the effect of radiative cooling. The variation in outflow parameters is demonstrated to lead to a variation in number density up to the termination shock, after which there is no effect in the post-shocked regions. On the other hand, eruptions increase the size of the astrosphere and cause the termination shock to oscillate between the inner boundary and the astropause. Galactic cosmic ray modulation within these types of astrospheres is also studied using a 1D stochastic differential equation model. It is shown that, even though these astrospheres are considerably larger than the heliosphere, calculated cosmic ray differential intensities remain larger than what is observed in the heliosphere at Earth, implying lower levels of modulation related to larger cosmic ray diffusion coefficients. During eruptive events, modelled cosmic ray intensities fluctuate due to the oscillating termination shock, and varying plasma parameters. It is also shown that such behaviour, can in principle, lead to the acceleration of these particles, but the results of this study, due to the 1D approach taken to solving the Parker transport equation, are argued to represent an upper limit to this phenomenon.