High Flow Research Articles

Company reputation and dividend payout

Purpose The purpose of this paper is to examine the association between company reputation and dividend policy. Design/methodology/approach In this study, sample of 98,809 firm-year observations from 22 countries covering 2005–2016 were used. Findings Firm reputation concerns are associated with higher propensities to pay dividends and payout ratios. Further, this positive effect is more pronounced for firms with high free cash flows, high information asymmetry and low institutional monitoring. The results are robust to an instrumental variable approach, propensity score matching and the Heckman two-stage correction approach while addressing endogeneity concerns. Practical implications These findings have significant implications for various stakeholders, such as existing and potential investors, managers, policymakers and regulators, by providing insights into the relationship between corporate reputation and firm dividend payout decisions. Corporate reputation is highlighted as crucial for accessing finance, emphasizing the role of national regulators and policymakers in facilitating firms' efforts to improve their reputation. The study highlights the dynamics of corporate reputation and dividend payout, calling for proactive engagement from regulators and policymakers. Crafting policies conducive to reputation-building can enhance firms' financial prospects, indicating the need for strategic interventions at managerial, regulatory and policy levels. Understanding the influence of economic context is crucial for firms to tailor reputation management strategies and optimize funding opportunities in different economic environments. Originality/value Overall, results suggest that reputation serves as a disciplining mechanism, where firms will pay dividends to maintain their reputations.

Lower mortality risk associated with remdesivir + dexamethasone versus dexamethasone alone for the treatment of patients hospitalized for COVID-19

Abstract Background Treatment guidelines were developed early in the pandemic when much about COVID-19 was unknown. Given the evolution of SARS-CoV-2, real-world data can provide clinicians with updated information. The objective of this analysis was to assess mortality risk in patients hospitalized for COVID-19 during the Omicron period receiving remdesivir+dexamethasone versus dexamethasone alone. Methods A large, multicenter US hospital database was used to identify hospitalized adult patients, with a primary discharge diagnosis of COVID-19 also flagged as “present on admission” treated with remdesivir+dexamethasone or dexamethasone alone from December 2021 to April 2023. Patients were matched 1:1 using propensity score matching and stratified by baseline oxygen requirements. Cox proportional hazards model was used to assess time to 14- and 28-day in-hospital all-cause mortality. Results A total of 33 037 patients were matched, with most patients ≥65 years old (72%), White (78%), and non-Hispanic (84%). Remdesivir+dexamethasone was associated with lower mortality risk versus dexamethasone alone across all baseline oxygen requirements at 14 days (no supplemental oxygen charges: adjusted hazard ratio [95% CI]: 0.79 [0.72-0.87], low flow oxygen: 0.70 [0.64-0.77], high flow oxygen/non-invasive ventilation: 0.69 [0.62-0.76], invasive mechanical ventilation/extracorporeal membrane oxygen (IMV/ECMO): 0.78 [0.64-0.94]), with similar results at 28 days. Conclusions Remdesivir+dexamethasone was associated with a significant reduction in 14- and 28-day mortality compared to dexamethasone alone in patients hospitalized for COVID-19 across all levels of baseline respiratory support, including IMV/ECMO. However, the use of remdesivir+dexamethasone still has low clinical practice uptake. In addition, these data suggest a need to update the existing guidelines.

Population genetics of Babesia vogeli based on the mitochondrial cytochrome b gene

The current study aimed at population genetic characterization of B. vogeli based on the cytochrome b (cyt b) gene sequences (≥ 685 bp) available in the GenBank. Phylogenetic trees placed all the sequences of B. vogeli in a single large monophyletic clade; however, it was further divided into two subclades (Bv1 and Bv2). Out of seven nucleotide variations observed between Bv1 and Bv2 subclades, four were synonymous (G92A, C170T, T488C and A659G), and three were non-synonymous (G324A, C438A and G465A) resulting in amino acid substitutions at three places (V108I, L146I and V155I). Within different B. vogeli populations, the nucleotide and haplotype diversities were low. The median-joining haplotype network revealed only two haplotypes (Hap_1 and Hap_2). A geographical sub-structuring was noticed in the B. vogeli populations, with moderate genetic differentiation (FST = 0.05000; P < 0.05) and a very high gene flow (Nm = 4.75) between Indian and Chinese populations. Neutrality tests and mismatch distributions for the Indian population and the overall dataset of B. vogeli indicated a constant population size. This study provides the first insight into the genetic characterization, population genetics and haplotype network of B. vogeli based on the cyt b gene.

A Case of Rheumatoid Arthritis Complicating Interstitial Pneumonia with ADL Recovery through Visiting Nursing and Nasal High Flow Therapy

A Case of Rheumatoid Arthritis Complicating Interstitial Pneumonia with ADL Recovery through Visiting Nursing and Nasal High Flow Therapy

Successful Microsurgical Clipping under Extracorporeal Membrane Oxygenation Treatment for a Poor-Grade Subarachnoid Hemorrhage Patient with Severe Pulmonary Neurogenic Lung

AbstractHemorrhagic strokes are considered as contraindications of extracorporeal membrane oxygenation (ECMO) therapy because of anticoagulant administration and ECMO-associated coagulopathy. We present a rare case of successful microsurgical clipping under ECMO for a poor-grade subarachnoid hemorrhage (SAH) patient with severe neurogenic pulmonary edema (NPE). A 50-year-old man presenting with the sudden loss of consciousness was diagnosed with poor-grade SAH with severe NPE, and was intubated. Because of severe hypoxemia refractory to conventional treatment, venovenous ECMO was used 6 hours after admission. To avoid thrombosis inside the ECMO circuit despite no anticoagulants, a heparin-bonded ECMO was maintained at a comparatively high blood flow rate. Subsequently, the patient underwent a microsurgical clipping under ECMO. Intraoperatively we had difficulty in bleeding control, and therefore the multiple transfusions were necessary to correct anemia and ECMO-associated coagulopathy. The aneurysmal clipping was accomplished without hemorrhagic intracranial complications. After 2 years from onset, his activities of daily life were independent. To our knowledge, this is the first report of successful microsurgical clipping for poor-grade SAH under ECMO without any anticoagulants. The use of a heparin-bonded ECMO tubing, maintenance of a slightly higher ECMO pump speed, and multiple transfusions to correct ECMO-associated coagulopathy could make the micro-neurosurgical procedures under ECMO possible. This report demonstrated the possibility to extend the range of application of microsurgical clipping for poor-grade SAH patients requiring ECMO treatment.

Development and Deployment of Data-Driven Turbulence Model for Three-Dimensional Complex Configurations

Abstract In recent years, the synergy between artificial intelligence and turbulence big data has given rise to a new data-driven paradigm in turbulence research. Data-driven turbulence modeling has emerged as one of the forefront directions in fluid mechanics. Most existing studies focus on feature construction, selection, and the development of modeling frameworks, often overlooking the practical deployment and application of trained models. This paper examines the entire process from model construction to real-world deployment, using data-driven turbulence modeling for high Reynolds number flows over complex three-dimensional configurations as a case study. Key stages include data generation, input-output feature construction, model training, model compilation and optimization, deployment, and validation. We successfully implemented the entire workflow in a heterogeneous supercomputing environment and, through mixed programming techniques, integrated the resulting turbulence model into the PHengLEI open-source software framework. This allowed for mixed-precision simulations, with the main equations solved in double precision and the turbulence model in half precision. The new computational framework was validated through large-scale parallel numerical simulations on grids with tens of millions of elements for three-dimensional complex configurations. The results highlight the efficiency of our model deployment, with overall computational efficiency improving by 13.35% and the turbulence model’s solution speed increasing by approximately 3.9 times. The accuracy of the computations was also confirmed, with the average relative error in the lift and drag coefficients calculated by the data-driven turbulence model within 3%. Across various computing nodes, the relative error in the computed aerodynamic coefficients remained within 1%, demonstrating the framework's scalability. Notably, our contributions have been incorporated as a case study in the latest PHengLEI open-source project.

Effect of air preheating temperature on the dynamic behaviour of a swirled spray flame

The effects of the air inlet temperature on the dynamic behaviour of a spray flame are reported for different air flow rates. Dodecane droplets are generated through a pressurised nozzle and introduced in the combustion chamber fed with air via two co-rotating swirlers. The flow rate of dodecane is kept constant (1.24gs-1) while the air flow rate is changed from 28gs-1 to 35gs-1 and its temperature from 70°C to 220°C. Microphones are used to record the different dynamics observed while a camera and a Phase Doppler Anemometry system allow to monitor the flame and the fuel spray.For low flow rates (between 28gs-1 and 32gs-1, leading to an overall equivalence ratio ranging between 0.6 and 0.7), the pressure fluctuations start by increasing with an increase of the temperature until, for a given temperature, the pressure fluctuations suddenly drop. This threshold temperature depends on the air flow rate. When displaying the pressure fluctuation level as a function of the bulk velocity (taking both air flow rate and temperature into account), the curves collapse into a similar shape. The instability frequency monotonically increases with the bulk velocity. For high flow rates (between 32gs-1 and 35gs-1, leading to overall equivalence ratio ranging between 0.5 and 0.6), a hysteresis phenomenon is found. Pressure fluctuations are relatively high for constantly decreasing temperature conditions and have almost similar levels as those obtained for lower flow rates. When constantly increasing the temperature, the levels are much lower, showing a bi-stable behaviour for the pressure fluctuations at a given operating point. A simple analysis based on the acoustic energy balance equation allows to qualitatively retrieve the behaviour of the pressure fluctuations amplitude and frequency for the low flow rate cases.

Tectono-thermal evolution from the proximal to hyperextended domains of the northern South China Sea margin since initial rifting

The Pearl River Mouth Basin (PRMB) is located on the northern margin of the South China Sea (SCS). Heat flow measurements indicate that the PRMB is a typical ‘hot basin' characterized by a high background heat flow. However, the tectono-thermal evolution of the PRMB and the mechanisms involved are still controversial due to the different input parameters used in tectono-thermal models, small datasets and the limited area of the basin studied. We used tectono-thermal modelling with a multi-stage finite stretching model, constrained by extensive well data, to systematically analyse the tectono-thermal evolution of the PRMB since the onset of rifting. The study area was expanded relative to previous studies to cover both the proximal and hyperextended regions of the northern SCS margin, providing a more comprehensive understanding of its tectono-thermal history. Numerous wells and seismic data covering the entire basin were used, along with appropriate input parameters, to address the gaps in previous studies and to enhance the accuracy of the results. Our findings indicate that the PRMB underwent two phases of heating, primarily due to thinning caused by lithospheric extension during rifting. By the end of rifting, the Northern Depression Zone and the Kaiping Sag had reached peak heat flow, while the Panyu Lower Uplift and Baiyun Sag saw their highest heat flow since the initial rifting. The PRMB experienced thermal decay during the post-rift stage, but a significant reheating event occurred from 23.03 to 13.82 Ma, likely due to northwards lower crustal flow from the Baiyun Sag. The Panyu Lower Uplift and the Baiyun Sag had reached their peak heat flow by 13.82 Ma and the heat flow generally increased by 1–3 mW m −2 in the other studied areas during this stage. The basin's thermal decay slowed at 5.33 Ma and localized heating events linked to magmatic activities in the southern Dongsha Uplift were observed. In general, the proximal domain of the northern SCS margin reached peak heat flow by the end of rifting, whereas the hyperextended domain reached peak heat flow by 13.82 Ma. The heat flow in the hyperextended domain was generally higher than that in the proximal domain as a result of the thinner crust of the hyperextended domain caused by intense multiple lithospheric detachment–extensional thinning processes. During the rifting stage, the lithospheric extensional thinning process was the most important factor influencing the tectono-thermal evolution of the northern SCS margin, while lower crustal flow and magmatism were the most important factors during the post-rift stage.

Post-insufflation diaphragm contractions in patients receiving various modes of mechanical ventilation

BackgroundDuring mechanical ventilation, post-insufflation diaphragm contractions (PIDCs) are non-physiologic and could be injurious. PIDCs could be frequent during reverse-triggering, where diaphragm contractions follow the ventilator rhythm. Whether PIDCs happens with different modes of assisted ventilation is unknown. In mechanically ventilated patients with hypoxemic respiratory failure, we aimed to examine whether PIDCs are associated with ventilator settings, patients’ characteristics or both.MethodsOne-hour recordings of diaphragm electromyography (EAdi), airway pressure and flow were collected once per day for up to five days from intubation until full recovery of diaphragm activity or death. Each breath was classified as mandatory (without-reverse-triggering), reverse-triggering, or patient triggered. Reverse triggering was further subclassified according to EAdi timing relative to ventilator cycle or reverse triggering leading to breath-stacking. EAdi timing (onset, offset), peak and neural inspiratory time (Tineuro) were measured breath-by-breath and compared to the ventilator expiratory time. A multivariable logistic regression model was used to investigate factors independently associated with PIDCs, including EAdi timing, amplitude, Tineuro, ventilator settings and APACHE II.ResultsForty-seven patients (median[25%-75%IQR] age: 63[52–77] years, BMI: 24.9[22.9–33.7] kg/m2, 49% male, APACHE II: 21[19–28]) contributed 2 ± 1 recordings each, totaling 183,962 breaths. PIDCs occurred in 74% of reverse-triggering, 27% of pressure support breaths, 21% of assist-control breaths, 5% of Neurally Adjusted Ventilatory Assist (NAVA) breaths. PIDCs were associated with higher EAdi peak (odds ratio [OR][95%CI] 1.01[1.01;1.01], longer Tineuro (OR 37.59[34.50;40.98]), shorter ventilator inspiratory time (OR 0.27[0.24;0.30]), high peak inspiratory flow (OR 0.22[0.20;0.26]), and small tidal volumes (OR 0.31[0.25;0.37]) (all P ≤ 0.008). NAVA was associated with absence of PIDCs (OR 0.03[0.02;0.03]; P < 0.001). Reverse triggering was characterized by lower EAdi peak than breaths triggered under pressure support and associated with small tidal volume and shorter set inspiratory time than breaths triggered under assist-control (all P < 0.05). Reverse triggering leading to breath stacking was characterized by higher peak EAdi and longer Tineuro and associated with small tidal volumes compared to all other reverse-triggering phenotypes (all P < 0.05).ConclusionsIn critically ill mechanically ventilated patients, PIDCs and reverse triggering phenotypes were associated with potentially modifiable factors, including ventilator settings. Proportional modes like NAVA represent a solution abolishing PIDCs.

Research on factors affecting bubble and particle behavior in a three-phase flotation system based on COMSOL

ABSTRACT To investigate the impact of various parameters on bubble and particle dynamics in a flotation system, COMSOL software was utilized. The “two-phase flow – Level Set” module coupled with the “fluid particle interaction” module was used to explore the behavior of single bubbles and particle groups. The bubbles were set as a discrete phase to represent a group of floating bubbles. By combining the “Single-phase flow” module with dual “fluid-particle interaction” modules, we examined the interactions between bubble populations and particles within the system. The research results show that as the bubble diameter increases, the carrying effect of the bubbles on the particles becomes stronger. When the bubble radii are 1, 1.25, 1.5, 1.75, and 2 mm respectively, the maximum movement speed of the particles in the area increases by 3.0%, 2.3%, 5.1%, and 2.7%. The average speed of the particles increases by 7.9%, 7.3%, 9.0%, and 10.0%. Increasing the mass flow rate can increase the collision probability between particles and bubbles, thus increasing the flotation rate. However, a too high mass flow rate will make the state of bubbles unstable. When the mass flow rate is less than 1.5 kg/s, the bubbles remain stable. When the mass flow rate exceeds 1.5 kg/s, the severity of bubble splitting increases. In the study area, the irregularity of the bubble clusters results in a more chaotic flow field, leading to greater speed and displacement of the particles. Increasing the number of bubbles entering at one time and their initial speed enhances the impact of the bubble clusters on the solid particles. When the number of bubbles entering at one time is 5, 10, 15, and 20 respectively, the maximum movement speed of the particles increases by 6.9%, 8.1%, and 9.0%. When the initial speed of the bubble entering is 0, 0.1, 0.2, and 0.3 m/s respectively, the maximum movement speed of the particles increases by 6.4%, 3.0%, and 8.8%.

Logistic regression model for predicting risk factors and contribution of cerebral microbleeds using renal function indicators

BackgroundThe brain and kidneys share similar low-resistance microvascular structures, receiving blood at consistently high flow rates and thus, are vulnerable to blood pressure fluctuations. This study investigates the causative factors of cerebral microbleeds (CMBs), aiming to quantify the contribution of each risk factor by constructing a multivariate model via stepwise regression.MethodsA total of 164 hospitalized patients were enrolled from January 2022 to March 2023 in this study, employing magnetic susceptibility-weighted imaging (SWI) to assess the presence of CMBs. The presence of CMBs in patients was determined by SWI, and history, renal function related to CMBs were analyzed.ResultsOut of 164 participants in the safety analysis, 36 (21.96%) exhibited CMBs and 128 (78.04%) did not exhibit CMBs, and the median age of the patients was 66 years (range: 49–86 years). Multivariate logistic regression identified hypertension (OR = 13.95%, 95% CI: 4.52, 50.07%), blood urea nitrogen (BUN) (OR = 1.57, 95% CI: 1.06–2.40), cystatin C (CyC) (OR = 4.90, 95% CI: 1.20–22.16), and urinary β-2 microglobulin, (OR = 2.11, 95% CI: 1.45–3.49) as significant risk factors for CMBs. The marginal R-square (RM2) was 0.25. Among all determinants, hypertension (47.81%) had the highest weight, followed by UN (11.42%). Quasi-curves plotted using the bootstrap method (999 times) showed good agreement between the predictive model and actual observations.ConclusionHypertension, BUN, urinary β-2 microglobulin, CyC were risk factors for CMBs morbidity, and controlling the above indicators within a reasonable range will help to reduce the incidence of CMBs.

High flow nasal cannula versus continuous positive airway pressure on incidence of postoperative pulmonary complications after bariatric surgery

ABSTRACT Background High flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) can be used postoperatively to decrease postoperative pulmonary complications. Aim This study evaluated and compared the effect of HFNC versus CPAP on postoperative pulmonary complications in bariatric surgery. Patients and Methods Sixty adult ASA class II and III patients scheduled for bariatric operations were divided into two equal groups: the HFNC and CPAP groups. Results No significant variations in HR and MABP were observed between groups. Mean SpO2% and PaO2/FiO2 readings were lower on ICU admission than pre-induction (p < 0.001). However, after the intervention, readings significantly increased (p < 0.001). Respiratory rate and PaCO2 levels were higher upon ICU admission than pre-induction in both groups (p < 0.001). After the intervention, they decreased significantly during all assessment times compared to ICU admission time (p < 0.001). Both groups had lower lung ultrasound scores at ICU discharge than on admission (p < 0.001). Still, no significant variations in scores observed between groups upon admission and before discharge. No significant variations were found in the incidence of postoperative pulmonary complications and duration of stay in hospital. Conclusion HFNC and CPAP decrease atelectasis and improve respiratory parameters postoperatively in morbidly obese persons after bariatric operation.

Collective free improvisation in the Flemish general music classroom: Probing student’s lived experience through flow

The aim of this study is to explore the lived experience of students ( N = 1,282) in general education engaging in collective free improvisation (CFI). Fourteen music teachers implemented a CFI lesson in 69 classes in Flanders (Belgium). Lived experience was measured using a Dutch version of the Flow State Scale for Occupational Tasks. This scale reflects the degree of Sense of Control, Positive Emotional Experience and Absorption by Concentrating. In addition, teachers’ reflections were mapped by means of an online survey. Overall scores on the 3 dimensions of the Flow scale averaged greater than or equal to 5 (7-point Likert scale). Results show a difference in total flow between students who already played an instrument and those who did not. Students who play an instrument score significantly higher on the factor ‘Sense of Control’. Conversely, the flow scores on the factors ‘Absorption by Concentration’ and ‘Positive Emotional Experience’ do not differ between instrumentalists and non-instrumentalists. Given the relatively high flow scores, we conclude that this type of musical engagement can be used for instrumentalists as well as non-instrumentalists. Although CFI was a new experience for the teachers, they indicated to continue using it in the future.

Experimental Investigation on collection efficiency of Deep-Sea hydraulic collection parameters

Hydraulic suction collection has been extensively utilized in deep-sea mining due to its high flow rate and efficiency. This paper introduces a novel hydraulic collection model to investigate the impact of various collection parameters on collection efficiency. We analyze the effect of different ore collection parameters on collection efficiency using a radial basis function network and make predictions. The optimal parameter range was obtained by performing combined parameter experiments. The two-parameter combination give better results compared to a single parameter. A theoretical model of collection efficiency is established based on experimental observations and principles of water jet theory. The accuracy of the model is confirmed through experimental validation, and the research findings can provide valuable insights for the ore collection process in deep-sea mining.

Assessment of monthly to daily streamflow disaggregation methods: A case study of the Nile River Basin

Study regionThe Nile River Basin Study focusThe lack of observed streamflow data at a short time scale poses a critical challenge for calibrating and validating hydrologic models. Therefore, many disaggregation methods were developed, resulting in various relative performances without a clear indication of the optimal choice. This study aims to iteratively assess eight monthly to daily streamflow disaggregation methods at 21 major subbasin outlets in the Nile River Basin (NRB) to identify the best-performing ones. These methods include one proportionality method and seven interpolation methods, i.e., linear, 2nd-order spline, 3rd-order spline, Piecewise Cubic Hermite Interpolating Polynomial (Pchip), Modified Akima (MAkima), mean preserved 2nd-order spline, and mean preserved 3rd-order spline. We assessed these methods using three metrics and visual investigations. New hydrologic insights for the regionThe results showed that the interpolation methods performed well, better than the proportionality method. However, their performances decreased at stations with high daily streamflow fluctuations. The interpolation methods’ performances were similar in mimicking the daily values but significantly different in preserving the mass balance. The mean preserving 3rd-order interpolation method (Lai 22) was the best in preserving the mass balance and capturing the low, moderate and high flows and, therefore, selected to generate the daily flow data in the NRB. The results of this study can guide a reliable method for obtaining daily streamflow data, which is important for the hydrologic and water management studies in the NRB.

Bismuth Single Atoms Regulated Graphite Felt Electrode Boosting High Power Density Vanadium Flow Batteries.

Vanadium flow batteries (VFBs) are considered one of the most promising candidates for large-scale energy storage. However, VFBs suffer from relatively low power density due to severe electrochemical polarization. Herein, we report Bi single atoms supported by an N-doped carbon-regulated graphite felt electrode (Bi SAs/NC@GF) with high electrocatalytic activity and stability, owing to the greatly improved active sites and optimized Bi-N4 configuration. Electrochemical in situ characterization and theoretical calculations elucidate the desolvation process and specific inner sphere reaction mechanism of [V(H2O)6]3+/[V(H2O)6]2+. As a result, a VFB single cell assembled with Bi SAs/NC@GF achieves a much higher energy efficiency of 81.1% at 240 mA cm-2 than NC@GF (70.5%). Moreover, a 5 kW VFB stack equipped with Bi SAs/NC@GF is assembled for the first time and ran stably for over 400 cycles. This work confirms that a single-atom catalyst is efficient for scalable VFBs with high power density and low cost.

Clinical implementation and evaluation of stereotactic liver radiotherapy in inspiration breath-hold using nasal high flow therapy and surface guidance.

To evaluate two years of clinical experience with markerless breath-hold liver stereotactic radiotherapy (SBRT) using non-invasive nasal high flow therapy (NHFT) for breath-hold prolonging and surface guidance (SGRT) for monitoring. Heated and humidified air was administered via a nasal cannula (40 L/min, 80% oxygen, 34 °C). Patients performed voluntary inspiration breath-holds with visual feedback. After a training session, 4-5 breath-hold CT scans were acquired to delineate an internal target volume (ITV) accounting for inter- and intra-breath-hold variations. Patients were treated in 3-8 fractions (7.5-20 Gy/fraction) using SGRT-controlled beam-hold. Patient setup was performed using SGRT and CBCT imaging. A post-treatment CBCT was acquired for evaluation purposes. Fifteen patients started the training session and received treatment, of whom 10 completed treatment in breath-hold. Half of all 60-second CBCT scans were acquired during a single breath-hold. The average maximum breath-hold duration during treatment ranged from 47-108 s. Breath-hold ITV was on average 6.5 cm³/30% larger (range: 1.1-23.9 cm³/5-95%) than the largest GTV. Free-breathing ITV based on 4DCT scans was on average 16.9 cm³/47% larger (range: -2.3-58.7 cm3/-16-157%) than the breath-hold ITV. The average 3D displacement vector of the area around PTV for the post-treatment CBCT scans was 5.0 mm (range: 0.7-12.9 mm). Liver SBRT in breath-hold using NHFT and SGRT is feasible for the majority of patients. An ITV reduction was observed compared to free-breathing treatments. To further decrease the PTV, internal anatomy-based breath-hold monitoring is desired. Non-invasive NHFT allows for prolonged breath-holding during surface-guided liver SBRT.

Study on the Contribution of Different Pore Throat Sizes to Oil Displacement Efficiency in Fracture-Pore Tight Sandstone Reservoir

The pore throat and fracture system of tight sandstone reservoir are complex, the reservoir is highly heterogeneous, and the production often decreases rapidly, the development degree is low, and the development effect of water injection is poor. CO2 injection is an important means to supplement formation energy and achieve efficient reservoir development in tight reservoirs. Based on nuclear magnetic resonance technology (NMR) and high temperature and high pressure physical flow simulation experiment system, the contribution of different scales of pore throat and fracture to the improvement of oil recovery in different phases of CO2 -crude oil system is studied. The results show that the contribution of mesopores, macropores and fractures to oil displacement efficiency in the supercritical CO2 displacement stage reaches 74.58%. In immiscible CO2 displacement stage, the contribution of micropores, small pores and medium pores to oil displacement efficiency reached 73.27%. In the miscible CO2 displacement stage, the contribution of micropores and small pores to oil displacement efficiency reached 52.32%. In the supercritical CO2 displacement stage, the contribution of oil displacement efficiency is mainly provided by macropore throats and fractures. The contribution of immiscible and miscible CO2 displacement stage to oil displacement efficiency mainly comes from small pore throat with smaller scale.

A comparative study of optical and size properties of dissolved organic matter in the lower Mississippi River and Pearl River

Monthly water samples were collected from the lower Mississippi and Pearl Rivers between January 2009 and August 2011 to investigate the heterogeneity in the dynamic variations of dissolved organic carbon (DOC), colloidal organic carbon, chromophoric and fluorescence dissolved organic matter (CDOM and FDOM), PARAFAC-derived fluorescent components, and other optical properties including spectral slope, specific UV absorbance (SUVA), and fluorescence indices between the two contrasting river systems. The lower Mississippi River exhibits relatively lower concentrations of DOC (306 ± 41 μM C) and CDOM (27.9 ± 5.7 m−1 at 254 nm), featuring lower aromaticity (indicated by SUVA254) and apparent molecular weight (or higher spectral slope) with weak seasonal variability. The Pearl River, in contrast, has elevated levels of DOC (537 ± 212 μM C) and CDOM (66.4 ± 31.4 m−1), characterized by higher aromaticity, higher molecular weight, and significant seasonality, primarily originating from soil-derived allochthonous sources. The abundance of the >1 kDa colloidal DOC was, on average, 58 ± 3 % of the bulk DOC in the lower Mississippi River and 68 ± 6 % in the lower Pearl River. The >1 kDa high-molecular weight DOM (HMW-DOM) consistently had lower spectral slope and biological index (BIX) values, but higher humification index (HIX) values compared to both bulk DOM and low-molecular-weight DOM (LMW-DOM) counterparts. These trends could be representative of other similar large and small rivers. Four PARAFAC-derived fluorescent components (three humic-like and one protein-like) were identified for both rivers. A positive correlation between discharge and terrestrial humic-like fluorescent components indicated their dominant allochthonous sources, while the protein-like component decreased with increasing discharge, consistent with its autochthonic source and a dilution effect during high flow seasons. The occurrence of large flood events during the sampling period contributed to large DOC pulses, with DOM of higher aromaticity and HMW-DOM. This has important implications for coastal ocean ecosystems, which are increasingly impacted by river flooding events under changing climate conditions. Our results also provide an improved understanding of DOM dynamics in two representative rivers and establish a baseline dataset for future studies to assess changes in sources and composition of DOM and their impacts on the coastal ocean in response to climate, hydrological, and anthropogenic influences.

Hot Dab Associated Pneumonitis - a case report

BackgroundDabbing is recently getting popular among young adults. It is a new method of using the most active form of marijuana where large amounts of concentrated tetrahydrocannabinol are inhaled. Tetrahydrocannabinol is associated with a feeling of ‘High’ which makes the user feel joyous and relaxed. With increasing use of such techniques, dabbing becomes an important differential for evaluation of acute respiratory failure with pneumonitis especially in the adult population.Case presentationA Fifty-one years old Caucasian man presented to the hospital with chest pressure and shortness of breath. The patient was noted to be hypoxic, desaturating down to 82–83% on nasal cannula oxygen. Imaging revealed bilateral lung infiltrates. Patient was started on high flow oxygen, broad spectrum antibiotics and intravenous corticosteroids. The patient gradually improved and was able to come off oxygen completely. He was discharged home on prednisone taper.ConclusionsDabbing is a newer technique which has been gaining popularity for marijuana usage. With the legalization of marijuana, newer techniques are getting popular. Our case report emphasizes the importance of keeping dabbing as a differential when a patient presents with respiratory failure and has concerns for pneumonitis. Patients might not reveal until specifically asked about their practices.