Initial Gas Research Articles

Evaluation of the factors affecting mortality after cardiac arrest - do lactate and procalcitonin concentrations have any implications?

Mortality and morbidity rates are very high in patients admitted to the Intensive Care Unit (ICU) after cardiac arrest. In this study, we aimed to determine the mortality rates, risk factors, and predictive factors for mortality in post-cardiac arrest patients admitted to the ICU. Following approval from the Ethics Committee, we conducted a retrospective review of patient files for individuals over the age of 18 who received treatment for cardiac arrest in the ICU from January 2017 to June 2020. Demographic data of the patients, comorbidities, arrest location, etiology of arrest, duration of hospitalization, CPR duration, APACHE 2 scores, pH and HCO3 measurements in initial blood gases, lactate levels (1st, 6th, 12th, 24th hour), change in lactate levels (24-1), rate of lactate change, procalcitonin (PRC) levels (1st and 24th hour), change in PRC levels (24-1), rate of PRC change, and blood glucose levels were recorded. The patients were divided into two groups (survivors and non-survivors groups). 151 patients were included in the study. pH and HCO3 levels were lower in the non-survivors group than in the survivors group. Initial PRC levels were similar in both groups, but the 24th-hour PRC levels were higher, and the changes in PRC levels in the first 24 hours were greater in the non-survivors group. The lactate changes in the first 24 hours were higher in the non-survivors group. The receiver operating characteristic (ROC) curve showed that the HCO3 levels, 1st-, 6th-, 12th-, and 24th-hour lactate levels, and changes in lactate levels had predictability for mortality. In logistic regression analysis, we found that high 24th-hour lactate levels and changes in lactate levels were independent risk factors for mortality. Considering PRC and lactate levels, along with clinical examination and laboratory findings, may improve the accuracy of determining the prognosis of patients experiencing cardiac arrest.

Comparative Life Cycle Assessments and Economic Analyses of Alternative Marine Fuels: Insights for Practical Strategies

The growth of the global shipping industry has increased the interest in the environmental impact of this sector. The International Maritime Organization adopted the initial Greenhouse Gas strategy for reducing GHG emissions from ships at the 72nd Marine Environment Protection Committee in April 2018. In this study, we carried out a life cycle assessment of nine production pathways of alternative fuels, including LNG, ammonia, methanol, and biofuels, and conducted an economic analysis considering the life cycle carbon pricing of each fuel pathway. Our results indicate that biomass-based FT-diesel, e-methanol, and e-ammonia are the most environmentally friendly, with GHG reductions of 92%, 88.2%, and 86.6%, respectively. However, our net present value analysis of ship life cycle cost considering carbon price indicated that using those fuels would not be cost-effective during the target period of study. Sensitivity analysis was performed by changing the life cycle carbon pricing from the baseline scenario, and we investigated the approximate years for when these alternative fuels will become more cost-effective compared to conventional fossil fuels. Further, to provide practical implications for shipping stakeholders, we analysed the effect of blending the same kinds of fuels with different production pathways.

Programmable intratumoral drug delivery to breast cancer using wireless bioelectronic device with electrochemical actuation

ABSTRACT Objective Breast cancer is a global health concern that demands attention. In our contribution to addressing this disease, our study focuses on investigating a wireless micro-device for intratumoral drug delivery, utilizing electrochemical actuation. Microdevices have emerged as a promising approach in this field due to their ability to enable controlled injections in various applications. Methods Our study is conducted within a computational framework, employing models that simulate the behavior of the microdevice and drug discharge based on the principles of the ideal gas law. Furthermore, the distribution of the drug within the tissue is simulated, considering both diffusion and convection mechanisms. To predict the therapeutic response, a pharmacodynamic model is utilized, considering the chemotherapeutic effects and cell proliferation. Results The findings demonstrate that an effective current of 3 mA, along with an initial gas volume equal to the drug volume in the microdevice, optimizes drug delivery. Microdevices with multiple injection capabilities exhibit enhanced therapeutic efficacy, effectively suppressing cell proliferation. Additionally, tumors with lower microvascular density experience higher drug concentrations in the extracellular space, resulting in significant cell death in hypoxic regions. Conclusions Achieving an efficient therapeutic response involves considering both the characteristics of the tumor microenvironment and the frequency of injections within a specific time frame.

Unveiling the origins of galactic bars: insights from barred and unbarred galaxies

ABSTRACT A significant fraction of local galaxies exhibit stellar bars, non-axisymmetric structures composed of stars, gas, and dust. Identifying key differences between the properties of barred and unbarred galaxies can uncover clues about the conditions for triggering bar formation. We explore the early stages of bar formation in a small sample of disc barred galaxies extracted from the TNG50 cosmological simulation, and compare their properties to those of unbarred galaxies. According to our results, the most important difference between barred and unbarred galaxies is that the former have systematically higher fractions of stellar to dark matter mass in their inner regions, from very early stages and prior to the formation of the bars. They harbour high initial gas content, fostering increased star formation rates and leading to a central mass concentration that grows faster over time compared to unbarred galaxies. Examining the evolution of the halo spin within $10\, \mathrm{ckpc}$ reveals that barred galaxies have higher angular momentum transfer from the disc to the halo. Curiously, both barred and unbarred galaxies share similar initial low values of the halo spin, consistent with those proposed in the literature for bar formation. Furthermore, we evaluate existing stability criteria to capture the complexity of the process, and investigate the effects of mergers, flybys, and environment as possible drivers of bar formation. We find no clear link between mergers and disc instabilities resulting in the formation of bars, even though some of the simulated barred galaxies might have been influenced by these events.

Modeling Novel Aqueous Particle and Cloud Chemistry Processes of Biomass Burning Phenols and Their Potential to Form Secondary Organic Aerosols.

Phenols emitted from biomass burning contribute significantly to secondary organic aerosol (SOA) formation through the partitioning of semivolatile products formed from gas-phase chemistry and multiphase chemistry in aerosol liquid water and clouds. The aqueous-phase SOA (aqSOA) formed via hydroxyl radical (•OH), singlet molecular oxygen (1O2*), and triplet excited states of organic compounds (3C*), which oxidize dissolved phenols in the aqueous phase, might play a significant role in the evolution of organic aerosol (OA). However, a quantitative and predictive understanding of aqSOA has been challenging. Here, we develop a stand-alone box model to investigate the formation of SOA from gas-phase •OH chemistry and aqSOA formed by the dissolution of phenols followed by their aqueous-phase reactions with •OH, 1O2*, and 3C* in cloud droplets and aerosol liquid water. We investigate four phenolic compounds, i.e., phenol, guaiacol, syringol, and guaiacyl acetone (GA), which represent some of the key potential sources of aqSOA from biomass burning in clouds. For the same initial precursor organic gas that dissolves in aerosol/cloud liquid water and subsequently reacts with aqueous phase oxidants, we predict that the aqSOA formation potential (defined as aqSOA formed per unit dissolved organic gas concentration) of these phenols is higher than that of isoprene-epoxydiol (IEPOX), a well-known aqSOA precursor. Cloud droplets can dissolve a broader range of soluble phenols compared to aqueous aerosols, since the liquid water contents of aerosols are orders of magnitude smaller than cloud droplets. Our simulations suggest that highly soluble and reactive multifunctional phenols like GA would predominantly undergo cloud chemistry within cloud layers, while gas-phase chemistry is likely to be more important for less soluble phenols. But in the absence of clouds, the condensation of low-volatility products from gas-phase oxidation followed by their reversible partitioning to organic aerosols dominates SOA formation, while the SOA formed through aqueous aerosol chemistry increases with relative humidity (RH), approaching 40% of the sum of gas and aqueous aerosol chemistry at 95% RH for GA. Our model developments of biomass-burning phenols and their aqueous chemistry can be readily implemented in regional and global atmospheric chemistry models to investigate the aqueous aerosol and cloud chemistry of biomass-burning organic gases in the atmosphere.

Hydrate phase equilibrium conditions for H2S and CO2 gas mixture removal from natural gas: modeling and optimization study

In this study, for the first time, a comprehensive mathematical modeling of the optimal conditions for the gas hydrates formation of hydrogen sulfide (H2S) and carbon dioxide (СО2) was carried out with the aim of them removing from natural gas. The study was carried out on a model gas mixture close to the natural gas composition: CH4 – C2H6 – С3Н8 – n-С4Н10 – СО2 – H2S – N2. A temperature range of 268.15–283.15 К and a pressure range of 2.00–8.00 MPa were investigated. The efficiency was assessed based on the gas hydrate distribution coefficients. It was found that the gas hydrate extraction of H2S is more significantly affected by the concentration of H2S in the initial gas mixture. The gas hydrate extraction of СО2 is more significantly affected by the temperature and pressure of the gas separation unit. The maximum gas hydrate distribution coefficient of H2S is 42.05 at T = 268.15 K, p = 8.00 MPa. The maximum gas hydrate distribution coefficient of СО2 is 0.49 at T = 283.15 K, p = 8.00 MPa. Due to the small amounts of CO2 entrapped in gas hydrates, a scheme that combines a multi-stage hydrate-based and membrane technology has been suggested to purify natural gas further.

2.5-MHD models of circumstellar discs around FS CMa post-mergers: II. Stationary accretion stage

ABSTRACT We study the star–disc interaction in the presence of the strong magnetic field (B⋆ = 6.2 kG) of a slowly rotating star. This situation describes a post-merger of the spectral type B and has not been previously investigated. We perform a set of resistive and viscosity 2.5D-magnetohydrodynamical simulations using the PLUTO code. Based on our previous work, we consider the initial gas disc density ρd0 = 10−13 g cm−3 since it describes the conditions around IRAS 17449+2320 well. We find that the fall of gas towards the star occurs in the mid-plane, and remarkably, intermittent backflow takes place in the mid-plane in all of our models for R ≥ 10R⋆. However, we do not rule out that the funnel effect may occur and cause the accretion closer to the poles. Also, when larger values of viscosity (αν = 1) and stellar rotation rate (δ⋆ = 0.2) are considered, we find that the disc exhibits a thickening which is characteristic of FS CMa-type stellar objects. Additionally, we find that the poloidal magnetic field lines twist over short periods of time, leading to magnetic reconnection causing coronal heating that could explain the presence of the Raman lines found observationally in several FS CMa stars. Lastly, we find the formation of several knots in the magnetic field lines near and in the mid-plane of the disc which produce perturbations in the density and velocity components, as well as the formation of shallow gaps whose position depends on the inflation of the magnetic field lines.

Study on Combustion Characteristics of Low Concentration Coalbed Methane Induced by Hydrogen Jet based on Excess Air Ratio

Low concentration coal bed gas used for power generation is a better treatment scheme at present, which solves the problem of environmental pollution caused by the direct emptying of coal bed gas. Coal bed methane is a methyl alkyl fuel, and slow combustion rate will cause abnormal combustion phenomena such as large combustion cycle changes. The initial ambient gas concentration has a great influence on the development and propagation of the flame. In this paper, a constant volume bomb model is established to change the excess air coefficient of methane air premix in the initial constant volume bomb, and the change law of combustion heat release is analyzed. The results show that when hydrogen participates in the combustion stage, the combustion rate increases with the increase of excess air coefficient. When hydrogen is burned out, the combustion rate decreases with the increase of excess air coefficient.

Comparative Study of CO2 Storage Capacity Estimation in Depleted Oil & Gas Reservoir: A Case Study in Vermillion Basin Gulf of Mexico

CO2 emissions rates have seen an exponential growth from the 19th century up till date, if no drastic measures and plans are implemented to prevent this exponential growth the consequence will be devastating. The notion of achieving net-zero greenhouse gas emissions gained prominence through the Paris Agreement, a groundbreaking accord reached at the United Nations Climate Change Conference. This agreement was devised to mitigate the impact of greenhouse gas emissions. To execute the net-zero CO2 emission plan, the USDOE has set a new goal to remove gigatons of carbon dioxide (CO2 ) from the atmosphere and durably store it for less than $100/ton of net CO2 -equivalent. Making such a goal a reality requires an accurate estimation of CO2 storage capacity for the successful implementation of Carbon Capture and Storage (CCS) technologies, and the assessment of the impact of CCS to the reduction of CO2 emissions. Hence this paper serves as a template for accurately estimating CO2 storage capacity in depleted saturated oil reservoirs with initial gas cap using three approaches: Volumetric, Production and Correlation-based methods and compares the accuracy of the estimates. A case study was conducted on a depleted VR273_Q combination sand in the Vermillion Basin, Gulf of Mexico (GOM). The deterministic and stochastic (P50) CO2 storage capacity estimates from the Volume-based method are 1.21 million tonnes (Mt) and 1.23 Mt respectively, while the deterministic CO2 storage capacity estimates from the Production and Correlationbased method are 1.32 Mt and 1.41 Mt respectively. All three approaches showed similar results, with little deviations attributed to petrophysical uncertainties arising from data gaps i.e., absence of well logs to key wells. However, these uncertainties are captured by Stochastic (P90) CO2 storage capacity estimates of 1.47 Mt from the Volume-based method. Although the Correlation-based approach slightly overestimates the CO2 storage capacity, it can be used as a starting point for quick estimation as it only requires production data which are readily available on various databases for GOM. Finally, through this paper, opportunities for concerned agencies to make well-informed energy-related policies and business decisions are made possible.

Experimental and modeling study of volatile organic compounds adsorption over zeolitic monolith adsorbent

In this study, a coupled mass and momentum model is developed and solved to describe the dynamic adsorption of a single adsorbate over honeycomb structured zeolite under industrial operating conditions. The Linear Driving Force approximation was used to predict the kinetics of adsorption to the solid-phase mass transfer and Navier Stokes equations were solved both radially and axially under laminar flow conditions through the honeycomb channels. To investigate the effect of key input parameters on model results, a sensitivity analysis was performed. Modeling and experimental results compared the effects of different initial concentrations and gas stream face velocities under a range of conditions to determine adsorption capacity, removal efficiency, and the 5% breakthrough time. Overall, the model output was in good agreement (less than 5% mean absolute relative error in concentration) with the experimental results under industrially relevant operating conditions. Modeling results illustrated that the radial velocity distribution over the monolith channels has an important effect on the shape of the breakthrough curve as well as the 5% breakthrough time. Both experimental results and modeling predictions showed that the long tails of the adsorption breakthroughs were the result of the non-uniform flow distribution, which resulted in delayed saturation of the outer honeycomb channels.

Caecal dilatation and dislocation in 20 dairy cows. A retrospective study.

A total of 20 cows with caecal dilatation and dislocation were included in this retrospective study. The aim of the study was to describe the findings of the initial clinical examination, the haematological, biochemical and venous blood gas analysis as well as the therapeutic management and the surgical findings of these cases. A positive simultaneous percussion and auscultation in the right flank as well as rectal palpation of the distended caecum were the most common findings in 90% of the animals. Increased haematocrit, hyperlactateaemia and hyperglycaemia were the most often occurring laboratory findings. Conservative treatment using neostigmine s.c. (0.025mg/kg) was successful in three out of four cases. Surgical therapy including laparotomy in the right flank and typhlotomy was performed in 17 cases. Caecal dilatation (n=9), retroflexion (n=4) and torsion (n=4) were revealed intraoperatively. During surgery in three cows, the caecum had filled once again with fluid content and typhlotomyhad to be repeated. Typhlectomy was not necessary in any of these cows. A relaparotomy due to recurrence of the caecal disorder was not required in any of the cases during hospitalisation. The postsurgical treatment included antibiotics, neostigmine in all cows and fluid therapy in the majority of the animals. Laxative treatment using 250 g sodium sulphate twice daily per os was applied in 10 cases. All cows were discharged from the clinic and returned to the farm.

Gas pressure, in-situ stress and coal strength effects on the evolution process of coal and gas outbursts based on the experimental data

ABSTRACT This paper investigated the effects of gas pressure, in-situ stress, and coal strength on coal and gas outbursts (CGO) based on the laboratory CGO experimental data. Based on the hypothesis of the comprehensive of CGO, the single-factor control variable method was used to analyze and evaluate the relative outburst intensity, the characteristics of outburst holes, the distribution of pulverized coal, the drops of outburst gas pressure, and the pulverized coal density under different outbursts experimental condition. The improved CGO energy equation and instability criterion are proposed as a direction to study the occurrence of CGO as an energy evolution direction. Furthermore, the results shows that the initial outburst gas pressure was 0.45 MPa during the experimental conditions of in-situ stress was 5 MPa, and the coal strength was 0.24 MPa. The gas pressure is directly proportional to the relative outburst intensity, while the in-situ stress and coal strength are inversely proportional to the relative outburst intensity. After the CGO occurred, the outburst coal always show spallation and pulverization characteristics. The results highlight that the gas pressure plays a key role in pulverizing and throwing out the pulverized coal, and the in-situ stress mainly plays a role in destroying the coal, and the coal strength plays a resistance role during the CGO occurs. It is also found that pulverized coal particles size less than 0.28 mm can be used to represent the distribution pattern of the total weight of outburst pulverized coal particles in the different outburst interval. These results clearly illustrate that using effective methods to control gas pressure, in-situ stress, and coal strength has an important role in preventing and controlling CGO on coal mining sites.

Transdermal exposure to Chrome-III oxide resulting in intoxicaitons and morbidity in two tanning workers—a case report

Here, we report two cases of chrome-III oxide intoxications following transdermal exposure in tanning workers. A 58-year-old man (case 1) and his 41-year-old co-worker (case 2) were brought to our ED with unconsciousness six hours after accidental transdermal exposure to chrome-III oxide crystals (Tankrom® AB, Chrome-III oxide 25.5% and Schorlemmer Basicity 33%). Upon arrival, both patients presented with agitation and chemical burns affecting 11% (case 1) and 3% (case 2) of their total body surface area, respectively. Chemical burns were mainly distributed on injured skin. Initial arterial blood gas analysis revealed moderate (case 1, pH: 7.268) to mild acidosis (case 2, pH: 7.352). One of our patients (case 1) had significant respiratory depression. Laboratory results of case 1 and case 2 showed increased white blood cell counts, (16,630 mm3 and 19,950 mm3) and elevated blood glucose (178 mg/dL and 193 mg/dL), creatinine (1.33 mg/dL and 1.52 mg/dL), liver enzyme (aspartate aminotransferase/alanine aminotransferase of 416/322 U/L and 141/118 U/L) and creatine phosphokinase level (474 U/L and 566 U/L), respectively. Radiologic examinations revealed an orbital wall fracture and L2 compression fracture in case 1, while case 2 had a subdural hematoma, subarachnoid hemorrhage and scapular fracture and had to undergo an operation for external ventricular drainage. Both patients became alert on day three (case 1) and day six (case 2) and were discharged on day 27. We serially measured their serum and urinary chromium concentrations after hospital arrival. The calculated serum half-lives were 35.7 hours and 25.1 hours, and urinary half-lives were 2.3 hours and 2.5 hours in case 1 and case 2, respectively. We suggest that transdermal exposure to chrome-III oxide, especially to injured skin, may result in significant toxicity and morbidity. Therefore, it is essential to take necessary precautions and preventive measures to avoid transdermal exposure to chromium.

Lunar Mare Lava Flow Dynamics and Emplacement: Predictions of Non-Newtonian Flow Dynamics, Syn- and Post-emplacement Cooling and Volatile Release Patterns, and Vertical and Lateral Flow Structure Development

We apply basic principles of magma ascent from deep source regions and its eruption into a low-gravity vacuum environment to develop a theoretical treatment of the fluid dynamics and thermodynamics of mare basalt lava flow emplacement and evolution on the Moon. The vacuum conditions influenced the release of volatiles in magma passing through lava fountains, thus controlling the syn- and post-emplacement vesicularity of the resulting deposits. To explain observed lengths and volumes of Mare Imbrium–type flows, high (106–105 m3 s−1) initial magma eruption rates were needed. Combined with low lunar magma viscosity, these caused flows to be initially turbulent. Resulting high radiative heat loss and consequent high crystallization rates caused rapid non-Newtonian rheological evolution and suppression of turbulence at tens of kilometers from vents. Slower cooling rates in the subsequent laminar parts of flows imply distinctive crystal growth rate histories. In a four-phase sequence, (i) initial transient dike-tip gas release followed by (ii) Hawaiian fire fountain activity with efficient volatile loss (iii) transitioned to (iv) Strombolian explosions in a lava lake. Late-stage lava now able to retain volatiles intruded and inflated existing flow deposits after flow front advance ceased. Volatiles forced out of solution by second boiling as lava cooled caused additional inflation. Low gravity and lack of atmospheric pressure commonly produced very vesicular lava. Escape of such lava through cracks in flow crusts is a possible source of ring-moat dome structures; collapse of such lava may explain irregular mare patches.

Study on the influence of stress constraint conditions on multi-scale gas emission characteristics in in-situ coal

Gas drainage in boreholes is characterized as an essential means to control abnormal gas emissions during mining. Unfortunately, its drainage efficiency is terribly restricted by high in-situ stress in deep underground coal seams. Gas drainage involves gas emission under stress constraint conditions (SCCs), as well as multi-scale gas migration (gas desorption, diffusion, and seepage). Nevertheless, how SCCs influence gas emission behaviors remains unclear. Considering this status quo, this paper focuses on researching He and CH4 emissions under different SCCs, and analyzes the influence of SCCs on gas emission by integrating the initial gas diffusion coefficient and the diffusion attenuation coefficient. In addition, a novel method for calculating equivalent diffusion and seepage pore radii by the T2 spectrum of nuclear magnetic resonance was proposed. Finally, according to the multi-mechanism gas emission model that tracks the dynamic evolutions of the equivalent diffusion and seepage pore radii, the influences of equivalent pore radius and pressure on the conductance of different diffusion mechanisms were further quantitatively analyzed. The research in this paper is expected to provide a theoretical reference for efficient gas drainage in deep coal seams.

Схемы бурения газодренажных скважин в выявленные зоны нарушения сплошности горного массива

. In order to find out the nature of the distribution of the stress state in the bottom-hole part of the massif and its effect on the development of cracks ahead of the face, the volume-stress state ahead of the faces of the preparatory workings was determined, and the nature of the zones of crack development (destruction) ahead of the face of the preparatory workings was determined, taking into account the cleavage of cracks in the array. As a result of the analysis of the zones of explosive destruction in the bottom-hole zone of the mine, it was revealed that the zones of crack development (destruction) in front of the mine face have an ambiguous character both in the height of the face and along each of the layers. This should be taken into account both when laying gas drainage wells and when drilling them. The development was carried out by the GPC tunneling combine from top to bottom. According to the regulatory documents, when carrying out the conveyor bremsberg, the current forecast of the emission hazard for the initial gas release rate and the output of the drill pin, as well as the forecast for the amplitude-frequency characteristics of the acoustic signal, is applied. To compare the effectiveness of methods for reducing the natural gas content of the D6 formation, comparisons were made of the results of the operation of reservoir degassing wells. The conducted studies allow us to identify a number of advantages of intensive degassing of the coal massif, directed along the course of production, in comparison with degassing by wells with drilling of the contour of future production.

Formation of Transitional cE/UCD Galaxies through Massive/Dwarf Disc Galaxy Mergers

The dynamics of the merger of a dwarf disc galaxy with a massive spiral galaxy of the Milky Way type were studied in detail. The remnant of such interaction after numerous crossings of the satellite through the disc of the main galaxy was a compact stellar core, the characteristics of which were close to small compact elliptical galaxies (cEs) or large ultra-compact dwarfs (UCDs). Such transitional cE/UCD objects with an effective radius of 100–200 pc arise as a result of stripping the outer layers of the stellar core during the destruction of a dwarf disc galaxy. Numerical models of the satellite before interaction included baryonic matter (stars and gas) and dark mass. We used N-body to describe the dynamics of stars and dark matter, and we used smoothed-particle hydrodynamics to model the gas components of both galaxies. The direct method of calculating the gravitational force between all particles provided a qualitative resolution of spatial structures up to 10 pc. The dwarf galaxy fell onto the gas and stellar discs of the main galaxy almost along a radial trajectory with a large eccentricity. This ensured that the dwarf crossed the disc of the main galaxy at each pericentric approach over a time interval of more than 9 billion years. We varied the gas mass and the initial orbital characteristics of the satellite over a wide range, studying the features of mass loss in the core. The presence of the initial gas component in a dwarf galaxy significantly affects the nature of the formation and evolution of the compact stellar core. The gas-rich satellite gives birth to a more compact elliptical galaxy compared to the merging gas-free dwarf galaxy. The initial gas content in the satellite also affects the internal rotation in the stripped nucleus. The simulated cE/UCD galaxies contained very little gas and dark matter at the end of their evolution.

Pulmonary Artery Measurements as Postnatal Prognostic Tool in Right Congenital Diaphragmatic Hernia

BackgroundRight-sided congenital diaphragmatic hernia (RCDH) is a rare and often fatal congenital anomaly, primarily attributed to lung hypoplasia, which is associated with small branch pulmonary artery (PA). This study investigated whether postnatal PA measurements obtained through echocardiography are associated with mortality or the extracorporeal membrane oxygenation (ECMO) requirement in neonates with RCDH. MethodsA retrospective study was conducted on neonates with RCDH born between 2008 and 2022. Echocardiography was performed on the day of birth. The diameter of the main PA (MPA) was measured at the maximal dimension, and the diameters of the left PA (LPA) and right PA (RPA) were measured at the bifurcation. The primary outcome was mortality or ECMO requirement. Parameters, including the LPA:MPA ratio, RPA:MPA ratio, Nakata index, McGoon ratio, and ejection fraction (EF), were analyzed and compared with the observed-to-expected lung-to-head ratio (o/e LHR), initial blood gas, and defect size as predictive values. ResultsAmong 39 neonates with RCDH, 25 (64.1 %) survived without ECMO. The non-survivor or ECMO group exhibited lower o/e LHR, reduced EF, smaller LPA and RPA diameters, and larger MPA diameter than survivors. Lower LPA:MPA ratio, Nakata index, McGoon ratio, and higher initial PaCO2 were associated with adverse outcomes. Notably, the LPA:MPA ratio showed the highest predictive capability (area under the curve, 0.983; p < 0.001). ConclusionThe LPA:MPA ratio is a promising postnatal predictor of mortality or ECMO requirement in neonates with RCDH. Additionally, Nakata index, McGoon ratio, and initial PaCO2 are significantly correlated with outcomes. Level of evidenceThis is a level III. Type of StudyPrognostic study.

Experimental study on the desorption law and diffusion kinetic characteristics of gas in raw coal and tectonic coal

To better reveal the nature of gas flow in raw coal and tectonic coal composite seams during gas extraction, experiments on the gas desorption and diffusion kinetic characteristics of raw coal and tectonic coal under different gas adsorption equilibrium pressures were carried out. Meanwhile, the applicability of Airey empirical formula was analysed, and the unipore model and bidisperse model were used to fit the experimental results and calculate the diffusion coefficient. The results show that the initial gas desorption rate and gas desorption volume of raw coal are much smaller than those of tectonic coal at the initial stage of gas desorption; at the later stage, the gas desorption rate of tectonic coal decays rapidly and the ultimate gas desorption volume tends to a stable value, however, the gas desorption rate of raw coal decays slowly and the ultimate gas desorption volume continues to increase. Airey empirical formula has some limitations in characterizing the gas desorption law in coal and is more suitable for fracture-rich “block” coal, but for the tectonic coal, the fitted ultimate gas desorption volume has a significant error from the actual one. The unipore model is suitable for describing some specific periods in the initial stage of the gas desorption process of raw coal, and the bidisperse model makes up for the defects of the unipore model and can accurately describe the gas diffusion law of tectonic coal. The study provides a theoretical basis for the scientific planning of coal and coalbed methane mining.

Paleoenvironmental Settings of the Soma Coal Basin (Turkey): Insights from Maceral Data, Biomarker, and Carbon Isotopic Composition.

Organic geochemical (TOC, pyrolysis, biomarker) and petrographic (maceral analysis) investigations together with organic carbon isotope studies were carried out to characterize in detail the depositional environment, determine the organic matter type, and assess the hydrocarbon production potential of three coal seams (KP1-upper, KM3-middle, and KM2-lower) in the Soma (Manisa, Western Anatolia) coal field in Turkey. The total organic carbon value of the upper coal seam ranged between 11.7 and 55.75%, the middle coal seam between 20.12 and 62.86%, and the lower coal seam between 50.03 and 65.71%. Coals in all three seams are characterized by low hydrogen index (HI) values (<151 mg HC/g TOC), low bitumen index (BI) (<19 g HC/g TOC), and quality index (QI) between 23 and 156 mg HC/g TOC. According to Rock-Eval pyrolysis data, the organic matter type of the coals is type III kerogen. Huminite reflectance, Tmax, and biomarker data (22S/22S+22R (C32) sterane, ββ/(αα + ββ) (C29) sterane, and MPI-1) indicate that the organic matter is not thermally mature and that the Soma-Manisa coal has reached the sub-bituminous rank. Rock-Eval data shows that coal is gas-prone and has not reached the maturity threshold required for initial gas production. The dominant maceral group is huminite while liptinite and inertinite macerals have been found in minor amounts. Groundwater index (GWI), vegetation index (VI), tissue preservation index (TPI), and gelification index (GI) parameters indicate a transition from limnic-limno-telmatic to limno-telmatic-telmatic environment from the upper seam to the lower seam. N-Alkane distributions show that paleoclimatic conditions have changed from KP1 to KM2. The higher abundance of pristane compared to phytane and low C35/C31-C35 homohopane index values demonstrate that the coals were deposited in a suboxic-oxic environment. The predominance of n-alkanes with generally high carbon number, relative variable abundances of C27-C28-C29 steranes, δ13C values, C/N ratios, and very low gammacerane index indicate a terrestrial ecosystem with nonmarine influence, although algae and microorganisms also contributed to the biomass.