Density Patterns Research Articles

Ordered silicon nanocone fabrication by using pseudo-Bosch process and maskless etching

Nanocone arrays are widely employed for applications such as antireflection structures and field emission devices. Silicon nanocones are typically obtained by an etching process, but the profile is hard to attain because anisotropic dry etching generally gives vertical or only slightly tapered sidewall profiles, and isotropic dry plasma etching gives curved sidewalls. In this work, we report the fabrication of cone structures by using masked etching followed by maskless etching techniques. The silicon structure is first etched using fluorine-based plasma under the protection of a hard metal mask, with a tapered or vertical sidewall profile. The mask is then removed, and maskless etching with an optimized nonswitching pseudo-Bosch recipe is applied to achieve the cone structure with a sharp apex. The gas flow ratio of C4F8 and SF6 is significantly increased from 38:22 (which creates a vertical profile) to 56:4, creating a taper angle of approximately 80°. After subsequent maskless etching, the sidewall taper angle is decreased to 74°, and the structure is sharpened to give a pointed apex. The effect of an oxygen cleaning step is also studied. With the introduction of periodic oxygen plasma cleaning steps, both the etch rate and surface smoothness are greatly improved. Lastly, it was found that the aspect ratio-dependent etching effect becomes prominent for dense patterns of cone arrays, with a greatly reduced etch depth at a 600 nm pitch array compared to a 1200 nm pitch array.

Controlled wettability of biphilic patterned surfaces for enhanced atmospheric water harvesting

Water is a vital component for all living organisms, yet persistent water scarcity remains a global challenge. One potential solution lies in replicating the atmospheric water collection mechanism observed in the Stenocara beetle, characterized by a dorsal surface featuring alternating hydrophilic and hydrophobic regions. In this study, we have designed and examined two distinct biphilic patterned surface configurations, integrating various technologies, to mimic the beetle's water collection strategy. Our investigation evaluates the efficiency of these surfaces in both capturing water from fog and condensing water from dew. For fog collection two parameters were the most impactful: the roughness and the wettability contrast between hydrophilic and hydrophobic zones. In contrast, dew condensation was influenced by additional parameters notably the patterns' size and density that directly affect the water contact angle. It is worth noting, however, that the optimal surface for fog collection may not necessarily coincide with the most effective surface for dew condensation. Furthermore, our research includes a comparative analysis between the theoretically predicted volume of water droplet departure and the empirically observed results.

Density and Distribution Pattern of Lola Snail (Trocus niloticus) in the Coastal Waters of Malaku Village, Central Maluku

The lola snail (Trochus niloticus) is a species of sea snail that has important economic value. This research aims to determine the density and distribution patterns of lola snails in the coastal waters of Malaku Village, Central Maluku. Sampling used a stratified random sampling method with line transects, the research location was divided into 3 stations. Stations I and III have plank coral substrates and dead coral fragments, while station II has rocky substrates and coral flats. The results of the research found that the total number of lola snail individuals found at the research location was 110 individuals spread across 3 research stations. The maximum size of lola snails found was 99.41 mm in diameter and the minimum size found was 47.18 mm in diameter. The highest density of Lola snails at each research station was 0.08 ind/m2 and the lowest was 0.05 ind/m2. The distribution pattern of Lola snails at the research location is a clustered pattern.

Landslides triggered by the 2022 Ms. 6.8 Luding strike-slip earthquake: An update

In this study, we established an updated coseismic landslide inventory of the 2022 Ms. 6.8 Luding earthquake. This version contains over 16,000 hand-digitized landslides with a total landslide area of 43.2 km2. We compared the spatial distribution of landslides and topographic, seismic, and geological factors on both sides of the seismogenic fault. The results show that the coseismic landslides of the Luding earthquake were mainly distributed along both sides (SWW and NEE blocks) of the seismogenic fault, with more landslides concentrated on the west side (SWW block). Compared to the NEE block, landslides on the SWW block are more likely to occur in areas characterized by higher elevations and reliefs. Otherwise, we observe an exponential decrease in both landslide area density and number density as the distance from the seismogenic fault increases, and the proximity to the fault is positively correlated with landslide size. Finally, we explored the relationship between landslide distribution and slip patterns by examining the detailed rupture characteristics of the Luding earthquake. Our analysis indicates that density patterns of coseismic landslides closely track the distribution of fault slip. The landslide abundance area corresponds to the area with the largest slip displacement of the surface rupture. The more the rupture extends into the shallow portion of the fault plane, the more landslides occur.

CBCT-3D radiographic analysis of an infected radicular cyst of the upper jaw: a case report

Objectives: The purpose of this case report is to find out the function of CBCT that can analyze in detail a radicular cyst case where CBCT has the ability to determine the density of a lesion. An overview of the density pattern of a radicular cyst can help determine the lesion and its margins. Case Report: : A 40-year-old patient complained of swelling in the palate that had been felt for about a year with a history of trauma due to an accident fifteen years ago. The patient underwent CBCT examination with the results of a hypodense area compared to the surrounding bone in the maxillary anterior area involving teeth 11,21,22 to 23 accompanied by a discontinuity of the cortical plate of the palatal bone and extending to involve the base of the nasal cavity. Part of the lesion is clearly demarcated, while the other side is diffuse. The suspected radiodiagnosis of the case was a moderately aggressive radicular cyst with a differential diagnosis of an odontogenic tumor. Conclusion: The final diagnosis of this case was a radicular cyst with chronic granulomatous inflammation, based on a combination of radiographic findings, clinical findings, and histopathological examination.

Spatial Analysis of Internally Displaced Persons’ Camps in Borno State, Nigeria

The situation in Borno State, Nigeria has been exacerbated by the ongoing insurgency led by Boko Haram in northeast Nigeria, leading to widespread displacement and the establishment of Internally Displaced Persons (IDP) camps. This study aims to identify the locations of IDP camps in Borno State and analyze their spatial distribution, density, and clustering patterns. Furthermore, it seeks to investigate the geospatial implications of these patterns. To achieve this, the study employs geospatial analysis techniques such as Kernel Density Estimation, Cluster and Outlier Analysis, Nearest Neighbour Analysis, and Spatial Autocorrelation Analysis. The data collected for this study includes location coordinates, satellite imagery, demographic information, and administrative maps. The findings reveal that the distribution of IDP camps in Borno State is non-random and demonstrates varying camp densities across senatorial districts, with predominant high-high clusters and a deliberate, non-random arrangement. These results align with spatial analysis theories, emphasizing the importance of recognizing hidden inequalities in IDP camps and informing targeted interventions and resource planning for a more effective and equitable humanitarian response in Borno State. The implications extend to policy planning and enhanced vulnerability assessment for effective humanitarian responses, stressing the need for tailored interventions based on identified hotspots that address root causes and implement both immediate and long-term solutions. Future research directions could involve more in-depth investigations into the influencing factors, socio-economic impacts, and temporal dynamics of spatial patterns in displacement.

Development of a Length-Based Cell-State Framework Toward the Re-Creation of Large-Scale Dense Congestion Patterns

This paper presents the results and novel findings of generating a simplified version of the prevailing traffic features that existed during a major evacuation. Leveraging the underlying framework provided by the widely used cell transmission model, the desire is to reconstruct the unique characteristics of large congestion patterns that propagate under dense traffic states, where limited attempts at scaling this base model have occurred. The length-based cell-state framework presented can reproduce large spatiotemporal congestion patterns that exist, specifically from large-scale evacuations. To further simplify, the framework considers traffic state heuristics which are calibrated through oblique cumulative count and occupancy curves. As a result of this preprocessing technique, an artifact was found from the use of the cumulative curves under the lens of Newell’s two-phase traffic flow theory where three unique, separate queued regimes were identified within the fundamental diagrams. The methodology re-created a unique large-scale congestion pattern that existed during a past regional evacuation event, Hurricane Irma, the subject of this paper. To test this methodology, a large-scale congested period was analyzed, both with probe vehicle trajectory data and stationary radar detector data. Results demonstrate that traffic re-creation into state-based contours was able to be verified near a 90% level of confidence even at large spatiotemporal extents.

Increased susceptibility to ischemia causes exacerbated response to microinjuries in the cirrhotic liver.

Fractional laser ablation is a technique developed in dermatology to induce remodeling of skin scars by creating a dense pattern of microinjuries. Despite remarkable clinical results, this technique has yet to be tested for scars in other tissues. As a first step toward determining the suitability of this technique, we aimed to (1) characterize the response to microinjuries in the healthy and cirrhotic liver, and (2) determine the underlying cause for any differences in response. Healthy and cirrhotic rats were treated with a fractional laser then euthanized from 0 h up to 14 days after treatment. Differential expression was assessed using RNAseq with a difference-in-differences model. Spatial maps of tissue oxygenation were acquired with hyperspectral imaging and disruptions in blood supply were assessed with tomato lectin perfusion. Healthy rats showed little damage beyond the initial microinjury and healed completely by 7 days without scarring. In cirrhotic rats, hepatocytes surrounding microinjury sites died 4-6 h after ablation, resulting in enlarged and heterogeneous zones of cell death. Hepatocytes near blood vessels were spared, particularly near the highly vascularized septa. Gene sets related to ischemia and angiogenesis were enriched at 4 h. Laser-treated regions had reduced oxygen saturation and broadly disrupted perfusion of nodule microvasculature, which matched the zones of cell death. Our results demonstrate that the cirrhotic liver has an exacerbated response to microinjuries and increased susceptibility to ischemia from microvascular damage, likely related to the vascular derangements that occur during cirrhosis development. Modifications to the fractional laser tool, such as using a femtosecond laser or reducing the spot size, may be able to prevent large disruptions of perfusion and enable further development of a laser-induced microinjury treatment for cirrhosis.

Wolverine density, survival, and population trends in the Canadian boreal forest

AbstractThere is limited information available on wolverine (Gulo gulo) population density and trends in the boreal forest of North America. We estimated wolverine density using spatial capture‐recapture methods across 2 boreal forest study areas in Red Lake, Ontario (26,568 km2) and Rainbow Lake, Alberta (19,084 km2), Canada. We also used radio‐telemetry data to estimate annual survival of adult and sub‐adult wolverines and evaluated population trends with a stage‐based matrix model. We used an array of run poles and live traps to detect wolverines. In Red Lake over 3 winter field seasons (2019–2022), we detected 56 individual wolverines (17 females, 32 males, and 7 unknown sex), and in Rainbow Lake over 2 field seasons (2014–2016), we detected 48 individuals (19 females, 18 males, and 11 of unknown sex). Average densities in Red Lake and Rainbow Lake were 3.64 and 6.74 wolverines/1,000 km2, respectively. Adults and sub‐adults occurred at equal abundance. Spring snow cover, roads, and industrial developments were not associated with spatial patterns of wolverine density. Most deaths occurred near roads; wolverines were killed in fur traps set along roads, by wolves using roads to travel, and by vehicles. The largest source of death was from incidental (n = 6 in Red Lake) or licensed fur trapping (n = 8 in Rainbow Lake) and we report 8 injuries from fur trapping sets. Red Lake survival estimates for adults (0.87) and sub‐adults (0.86) contributed to a stable population trend. Rainbow Lake survival estimates for adults (0.66) and sub‐adults (0.50) contributed to a declining population trend based on a relatively low sample of radio‐days. Red Lake and Rainbow Lake combined survival estimates for adults (0.77) and sub‐adults (0.73) also contributed to a declining population trend. Our survival and population modeling suggests that human‐caused mortality is a significant risk to these populations. Our results can be applied to wolverine status assessments and used as benchmarks for future monitoring. Wolverine population stability or growth might be achieved by reducing incidental trapping deaths or injury and hindering human access to wolverine habitats through decommissioning or limiting development of industrial roads or other anthropogenic linear features.

P151 Nailfold capillaroscopy for prediction of novel severe organ involvement and mortality in systemic sclerosis

Abstract Background/Aims Nailfold capillaroscopy (NFC) has been suggested as a potential biomarker of disease severity in systemic sclerosis (SSc). Several studies report the association between capillary loss and disease severity however, the association of NFC abnormalities with novel severe organ involvement/progression and mortality in SSc has not been evaluated. We aim to evaluate the association of nailfold capillaroscopy (NFC) abnormalities with novel major organ involvement/progression and mortality in SSc. Methods Follow-up data from patients with SSc registered between 2000 and 2022 were analyzed. Patients underwent NFC at baseline. Baseline demographic data, antibody status, baseline pulmonary function, novel severe organ involvement/progression and mortality were registered. Novel organ involvement/progression was defined as new or progressive involvement of peripheral vasculature, lungs, heart, skin, gastrointestinal, kidney, musculoskeletal at 12 and 24 months of follow-up. The following NFC parameters were evaluated: capillary density, hemorrhages, enlarged and giant capillaries, avascular areas, organization of capillary architecture and scleroderma pattern (early/active/late). Logistic regression modelling was run to assess associations between NFC and clinical parameters, the occurrence of novel severe organ involvement and/or progression and mortality. Results 113 patients were included: 28 (25%) were male, 86 (76%) lcSSc and 27 (23%) dcSSc. 70 patients (61%) developed novel overall severe organ involvement/progression and 40 patients died (36%) during follow-up. Table 1 and table 2 summarizes the associations between NFC and novel severe organ involvement/progression and mortality during follow-up. Loss of capillary density was associated with overall severe organ involvement (p = 0.002), peripheral vascular involvement (p = 0.03), new ILD (p = 0.04) and skin progression (p = 0.01); avascular areas were associated with overall severe organ involvement (p = 0.03), new ILD (p = 0.03) and progression of ILD (p = 0.02) and scleroderma pattern was associated with overall severe organinvolvement (p = 0.03), peripheral vascular involvement (OR p = 0.04), new ILD (p = 0.004), progression of ILD (p = 0.03) and skin progression (p = 0.04). Mortality was associated with ILD (OR 2.56 CI 95% 1.5-7.2, p 0.04), DLCO <70% (2.34 CI 93% 1.42-6.23, p 0.03), a late pattern in NFC (3.42 95% CI 1.42-7.25, p 0.002), presence of hemorrhages (OR 1.77 95% CI 1.24-8.23, p0.034) and avascular zones (OR 6.22 95% CI 2.54-10.3, p 0.021). Survival rates from diagnosis at 10 years were lower in patients with NFC with active a late pattern (40% and 20%) compared with those with normal, unspecific and early pattern (100%, 90% and 70%) (p = 0.008 by log rank test) (figure 1). Conclusion NFC may be a potential biomarker in SSc for predicting novel severe organ involvement and/or progression and mortality. Abnormal capillary density, avascular areas and scleroderma pattern are predictors of overall severe organ involvement, peripheral vascular involvement, novel and progression of ILD and skin progression. Disclosure C. Sieiro Santos: None. P. Pérez García: None. J. Ordas Martínez: None. C. Álvarez Castro: None. E. Díez Álvarez: None.

Impact of infill density on morphology and mechanical properties of 3D printed ABS/CF-ABS composites using design of experiments

Metal Extrusion (MEX) is a leading 3D printing technology for polymers, enabling intricate designs and personalized products in various applications. The current study evaluate how infill density affects the tensile, flexural, compressive, Izod impact and fracture behaviour of Acrylonitrile Butadiene Styrene (ABS) and Carbon Fiber Reinforced-Acrylonitrile Butadiene Styrene (CF-ABS) specimens manufactured using the MEX method. Different infill densities of 20, 40, 60 and 80 % are used in the production of honeycomb infill pattern samples for investigating the mechanical as well as fracture behaviour of MEX ABS/CF-ABS components. The experimental runs of fabricated composites were tested using a digital Izod impact tester and servo-controlled hydraulic universal testing machine, following ASTM standard procedures. The experimental findings show that CF-ABS specimens with an 80 % infill density and honeycomb fill pattern showed significant improvements in tensile strength, modulus, yield strength and elongation. The flexural strength (64.74 %), flexural modulus (209.15 %), compressive strength (125.21 %), compressive modulus (108.34 %) and impact strength (38.91 %) of these specimens are comparable to those of 3D printed ABS specimens and other infill densities. The research shows that precise management of processing variables can greatly improve the mechanical properties of 3D-printed ABS samples, providing valuable insights for a range of applications.

Diverse and asymmetric patterns of single-neuron projectome in regulating interhemispheric connectivity

The corpus callosum, historically considered primarily for homotopic connections, supports many heterotopic connections, indicating complex interhemispheric connectivity. Understanding this complexity is crucial yet challenging due to diverse cell-specific wiring patterns. Here, we utilized public AAV bulk tracing and single-neuron tracing data to delineate the anatomical connection patterns of mouse brains and conducted wide-field calcium imaging to assess functional connectivity across various brain states in male mice. The single-neuron data uncovered complex and dense interconnected patterns, particularly for interhemispheric-heterotopic connections. We proposed a metric “heterogeneity” to quantify the complexity of the connection patterns. Computational modeling of these patterns suggested that the heterogeneity of upstream projections impacted downstream homotopic functional connectivity. Furthermore, higher heterogeneity observed in interhemispheric-heterotopic projections would cause lower strength but higher stability in functional connectivity than their intrahemispheric counterparts. These findings were corroborated by our wide-field functional imaging data, underscoring the important role of heterotopic-projection heterogeneity in interhemispheric communication.

Exploring Ecological, Morphological, and Environmental Controls on Coastal Foredune Evolution at Annual Scales Using a Process-Based Model

Coastal communities commonly rely upon foredunes as the first line of defense against sea-level rise and storms, thus requiring management guidance to optimize their protective services. Here, we use the AeoLiS model to simulate wind-driven accretion and wave-driven erosion patterns on foredunes with different morphologies and ecological properties under modern-day conditions. Additional sets of model runs mimic potential future climate changes to inform how both morphological and ecological properties may have differing contributions to net dune changes under evolving environmental forcing. This exploratory study, applied to represent the morphological, environmental, and ecological conditions of the northern Outer Banks, North Carolina, USA, finds that dunes experiencing minimal wave collision have similar net volumetric growth rates regardless of beach morphology, though the location and density of vegetation influence sediment deposition patterns across the dune profile. The model indicates that high-density, uniform planting strategies trap sediment close to the dune toe, whereas low-density plantings may allow for accretion across a broader extent of the dune face. The initial beach and dune shape generally plays a larger role in annual-scale dune evolution than vegetation cover. For steeper beach slopes and/or low dune toe elevations, the model generally predicts wave-driven dune erosion at the annual scale.

Antillean manatee (Trichechus manatus manatus) occurrence and grazing spots in three protected areas of Costa Rica

The Antillean manatee is a poorly studied marine mammal in Costa Rica. Its distribution covers the entire Caribbean coast, but sighting reports are scarce. This research was conducted in three protected areas (PA) where the species is primarily observed. The objectives were to determine the density patterns of sightings and grazing spots; to explore the relationship between grazing spots and sightings with geographic and temporal variables, for PA separately; to study the frequency of sightings and grazing spots according to season, month, and period of the day, for PA together; and to determine the pertinence of using a marine ecology application MarEco to register manatee sightings by the public. Data on manatee sightings and grazing spots gathered with the MarEco app, under a citizen science mechanism, were complemented with data obtained by the Tortuguero Conservation Area Administration (TCAA) through other means. The number of sighting records registered through MarEco during nine months was alike to the number of records reported to the TCAA over six years in two of the PA studied. The areas with the highest density of grazing spots and sightings matched with studies conducted 10 to 20 years ago. In two of the PA, sightings were most often associated with the rainy season, while fresh grazing spots were specially counted from 6:00 h to 8:59 h. The results suggest that manatees exhibit high site fidelity in the three PA, that their increased presence during the rainy season is likely due to increased availability of food, and that they perform feeding activity predominantly at night.

Method for the Experimental Identification of Variables and Configurations That Modify the Shape of the Macroscopic Fundamental Diagram

In this paper, we propose a method for establishing if a variable is capable of modifying the Macroscopic Fundamental Diagram (MFD) of a street network. The variables have many different configurations, and a simulation is performed for each one. Then, based on the output data of each simulation, the representative speed, density, and flow of the network are calculated. We use three metrics to establish if a variable affects the MFD: the first establishes a distance between the compared density and speed patterns, the second establishes a distance between capacities, and the third establishes a distance between critical densities. We select four variables to test our method: the precision of driving, the vehicles’ top speeds distribution, the procedure for selecting routes, and the procedure for selecting destinations; we determine whether each of these variables can modify the MFD shape. Additionally, we detect which configurations of a variable are able to reach and exceed the critical density (causing congestion) so we can establish which configurations are sustainable and which are not. The novelties of this work are twofold: (1) we introduce a method to detect if a variable modifies the MFD; (2) we establish if the selected variables modify the MFD.

Charge-conjugation asymmetry and molecular content: The [formula omitted] in matter

We analyze the modifications that a dense nuclear medium induces in the Ds0⁎(2317)± and Ds1(2460)±. In the vacuum, we consider them as isoscalar D(⁎)K and ▪S-wave bound states, which are dynamically generated from effective interactions that lead to different Weinberg compositeness scenarios. Matter effects are incorporated through the two-meson loop functions, taking into account the self energies that the D(⁎), ▪, K, and ▪ develop when embedded in a nuclear medium. Although particle-antiparticle [Ds0,s1(⁎)(2317,2460)+versusDs0,s1(⁎)(2317,2460)−] lineshapes are the same in vacuum, we find extremely different density patterns in matter. This charge-conjugation asymmetry mainly stems from the very different kaon and antikaon interaction with the nucleons of the dense medium. We show that the in-medium lineshapes found for these resonances strongly depend on their D(⁎)K/▪ molecular content, and discuss how this novel feature can be used to better determine/constrain the inner structure of these exotic states.

Investigating Fire–Atmosphere Interaction in a Forest Canopy Using Wavelets

Wildland fire–atmosphere interaction generates complex turbulence patterns, organized across multiple scales, which inform fire-spread behaviour, firebrand transport, and smoke dispersion. Here, we utilize wavelet-based techniques to explore the characteristic temporal scales associated with coherent patterns in the measured temperature and the turbulent fluxes during a prescribed wind-driven (heading) surface fire beneath a forest canopy. We use temperature and velocity measurements from tower-mounted sonic anemometers at multiple heights. Patterns in the wavelet-based energy density of the measured temperature plotted on a time–frequency plane indicate the presence of fire-modulated ramp–cliff structures in the low-to-mid-frequency band (0.01–0.33 Hz), with mean ramp durations approximately 20% shorter and ramp slopes that are an order of magnitude higher compared to no-fire conditions. We then investigate heat- and momentum-flux events near the canopy top through a cross-wavelet coherence analysis. Briefly before the fire-front arrives at the tower base, momentum-flux events are relatively suppressed and turbulent fluxes are chiefly thermally-driven near the canopy top, owing to the tilting of the flame in the direction of the wind. Fire-induced heat-flux events comprising warm updrafts and cool downdrafts are coherent down to periods of a second, whereas ambient heat-flux events operate mainly at higher periods (above 17 s). Later, when the strongest temperature fluctuations are recorded near the surface, fire-induced heat-flux events occur intermittently at shorter scales and cool sweeps start being seen for periods ranging from 8 to 35 s near the canopy top, suggesting a diminishing influence of the flame and increasing background atmospheric variability thereat. The improved understanding of the characteristic time scales associated with fire-induced turbulence features, as the fire-front evolves, will help develop more reliable fire behaviour and scalar transport models.

An Application of Interacting Boson Fermion-Fermion Model (IBFFM) for <sup>134</sup>Cs Nucleus

This work concerns the calculations of interacting boson fermion-fermion model (IBFFM) for the odd-odd nucleus <sup>134</sup>Cs. The energy levels (positive and negative parity states), electric transition probability B(E2), magnetic transition probability B(M1), quadrupole and magnetic dipole moments have been studied in this work. The IBFFM results are compared with the available experimental data. In the present work, the IBFFM pattern of total and parametric dependent level densities for the odd-odd nucleus <sup>134</sup>Cs is investigated and compared to the pattern found in previous investigations in the framework of combinatorial and spectral distribution approaches. When comparing the theoretical values with the available experimental values, it was found that there is a good match between them. This is due to the values of the Hamiltonian parameters that were found accurately, so this IBFFM model is considered one of the effective models in studying the nuclear structure of odd-odd nuclei. The level density of the odd-odd nucleus <sup>196</sup>Au is investigated in the interacting boson-fermion-fermion model (IBFFM) which accounts for collectivity and complex interaction between quasiparticle and collective modes. The IBFFM spin-dependent level densities show high-spin reduction with respect to Bethe formula. This can be well accounted for by a modified spin-dependent level density formula.

Mechanism of plasma chemistry in CO2 hydrogenation using a dielectric barrier discharge reactor

AbstractPlasma‐induced CO2 hydrogenation process has received much attention, while the related plasma chemistry has not been profoundly explored. Herein, electron‐induced and thermochemical effects on CO2 hydrogenation in a dielectric barrier discharge reactor were investigated. The temperatures for the discharge pattern transition for CO2/H2, CO2/H2/N2, CO2/H2/Ar, and CO2/H2/He mixtures were 623, 623, 600, and 600 K, respectively. CO2 conversion was controlled by electron‐induced reactions and was sensitive to discharge pattern and electron density but not electron energy. In contrast, product formation was governed by the thermo‐induced chemistry. These results are useful for a better understanding of plasma‐induced CO2 hydrogenation.

The Comparison of Ultrasound and Tomographic Images of Lung Involvement in Critically Ill Patients With COVID-19 Pneumonia: A Prospective Observational Study.

Introduction Computed tomography (CT) has a high sensitivity for diagnosing COVID-19 pneumonia in critically ill patients, but it has significant limitations. Lung ultrasonography (LUS) is an imaging method increasingly used in intensive care units. Our primary aim is to evaluate the relationship between LUS and CT images by scoring a critically ill patient who was previously diagnosed with COVID-19 pneumonia and underwent CT, as well as to determine their relationship with the patient's oxygenation. Methods This was a single-center, prospective observational study. The study included COVID-19 patients (positive reverse transcription polymerase chain reaction, RT-PCR) who were admitted to the intensive care unit between June 2020 and December 2020, whose oxygen saturation (SpO2) was below 92%, and who underwent a chest tomography scan within the last 12 hours. CT findings were scored by the radiologist using the COVID-19 Reporting and Data System (CO-RADS). The intensivist evaluated 12 regions to determine the LUS score. The ratio of the partial pressure of oxygen in the arterial blood to the inspiratory oxygen concentration (PaO2/FiO2) was used to assess the patient's oxygenation. Results The study included 30 patients and found a weak correlation (ICC = 0.45, 95% CI = 0.25-0.65, p < 0.05) between total scores obtained from LUS and CT scans. The correlation between the total LUS score and oxygenation (r = -0.514, p = 0.004) was stronger than that between the CT score and oxygenation (r = -0.400, p = 0.028). The most common sonographic findings were abnormalities in the pleural line, white lung, and subpleural consolidation. On the other hand, the CT images revealed dense ground-glass opacities and consolidation patterns classified as CO-RADS 5. Conclusion A weak correlation was found between LUS and CT scores in critically ill COVID-19 pneumonia patients. Also, as both scores increased, oxygenation was detected to be impaired, and such a correlation is more evident with the LUS score.