Higher Maximum Temperature Research Articles

Analysis of factors affecting the clinical management of infection in culture-negative patients following percutaneous endoscopic decompression: a retrospective study

BackgroundCulture-negative spinal infections after prophylactic antibiotic use in percutaneous endoscopic decompression are rare, and diagnostic difficulties and the risk of antibiotic-resistant infections complicate treatment. This study retrospectively analyzed the medical records of culture-negative patients following percutaneous endoscopic surgery to identify risk factors influencing antimicrobial therapy and provide insights for clinical management.MethodsData were retrospectively collected from patients who underwent lumbar percutaneous endoscopic decompression at the Affiliated Hospital of Qingdao University between January 2014 and June 2023. The patients’ medical records were reviewed. Patient demographics, hidden blood loss, daily blood glucose control, and maximum temperature during treatment were recorded as potential risk factors. C-reactive protein, procalcitonin, white blood cells, erythrocyte sedimentation rate, and the duration of antibiotic treatment were used as indicators of infection treatment. The impact of these risk factors on infection was then analyzed.ResultsThe results showed that blood glucose control was strongly correlated with the severity of infection (Beta = 0.60, P = 0.00), strongly correlated with short-term treatment effectiveness (Beta = 0.65, P = 0.00), and moderately correlated with the duration of antibiotic treatment (Beta = 0.41, P = 0.01). Hidden blood loss was moderately correlated with the severity of infection (Partial-R = 0.49, P = 0.00) and moderately correlated with the duration of antibiotic treatment (Partial-R = 0.48, P = 0.00). Hidden blood loss index was moderately correlated with the duration of antibiotic treatment (Partial-R = 0.50, P = 0.00). Female was a favorable factor to shorten the duration of antibiotic treatment (Beta = -0.25, P = 0.01), and higher maximum temperature during infection may indicate a longer duration of antibiotic treatment (Beta = 0.28, P = 0.02).ConclusionOur findings suggest that healthy blood glucose levels, a lower hidden blood loss and hidden blood loss index might help reduce the duration of antibiotic use after infection. Effective hemostasis during surgery to reduce hidden blood loss and good preoperative blood glucose control indicators are both beneficial measures for infection treatment.

Climatic Determinants of Shrimp Yields in Tamil Nadu, India: A Transfer Function Analysis

Shrimp aquaculture in Tamil Nadu plays a critical role in supporting livelihoods and contributing to exports but is increasingly vulnerable to climatic variability. This study investigates how seasonal precipitation, extreme temperatures, and lagged production impact shrimp yields in four key districts—Tiruvallur, Cuddalore, Thanjavur, and Nagapattinam—over the period 2015–2023. Using statistical models, we identify major trends and district-specific sensitivities. For instance, excessive summer and winter precipitation coupled with high maximum temperatures reduced yields in Tiruvallur, whereas warmer summer nights boosted production. In Cuddalore, yields were hampered by seasonal precipitation, elevated minimum temperatures, and the lingering effects of previous yields. Thanjavur’s production suffered from extreme temperatures and winter rainfall but benefited from milder winter nights. Nagapattinam showed unique dynamics, where winter precipitation and summer maximum temperatures enhanced yields, while summer rainfall and lagged production had adverse effects. These findings highlight the need for tailored, district-specific strategies to manage climate risks and sustain shrimp farming. For example, adaptive measures such as optimizing water management or selecting climate-resilient shrimp varieties could mitigate negative impacts. Future research could integrate factors like water quality and disease outbreaks to strengthen the sector’s resilience further.

Identification of climate change hotspots in the Mediterranean

The Mediterranean region has long been identified as a climate change hotspot. However, within the Mediterranean, there are smaller sub-areas that exhibit a higher risk of climate change and extremes. Previous research has often focused on indices based on mean climate values, yet extremes are typically more impactful on humans and ecosystems. This study aims to identify the most vulnerable sub-areas of the Mediterranean as climate change hotspots using two indices: the newly introduced Mediterranean Hotspot Index (MED-HOT) and the well-defined Regional Climate Change Index (RCCI). The MED-HOT focuses on extreme high maximum and minimum temperatures, rainfall, and drought, while RCCI assesses changes in mean climate conditions. By combining these indices, we provide an identification of Mediterranean hotspots, capturing both mean climate shifts and extremes. The spatiotemporal variation of both indices across the Mediterranean region is presented and the 20 subregions are categorized into distinct groups. The results reveal that the southeastern Mediterranean is at high risk according to both indices. Additionally, southern Italy is identified as high risk due to changes in mean climate (RCCI), while the northern part is at risk due to extreme events (MED-HOT). The Iberian Peninsula and Greece are also highlighted as vulnerable areas requiring extra attention.

Cheatgrass alters flammability of native perennial grasses in laboratory combustion experiments

Abstract Background The invasive annual grass cheatgrass (Bromus tectorum) increases fuel continuity, alters patterns of fire spread, and changes plant communities in sagebrush shrublands of the Great Basin (USA) and adjacent sagebrush steppe, but no studies have contrasted its flammability to native perennial grasses. Understanding cheatgrass flammability is crucial for predicting fire behavior, informing management decisions, and assessing fire risk in invaded areas. This study aimed to determine the flammability of cheatgrass compared to two native perennial grasses (Columbia needlegrass [Achnatherum nelsonii] and bluebunch wheatgrass [Pseudoroegneria spicata]) across a range of fuel moistures. Results All three grass species had decreased flammability with increasing fuel moisture. Columbia needlegrass averaged 11% lower mass consumption than cheatgrass, and bluebunch wheatgrass had longer flaming duration and higher maximum temperatures than cheatgrass and Columbia needlegrass. The addition of cheatgrass to each perennial grass increased combined mass consumption, flaming duration, and flame heights. For these three attributes, the impact differed by the amount of cheatgrass in the mixture. Maximum and mean temperatures during perennial grass combustion were similar with and without cheatgrass addition. Some attributes of Columbia needlegrass flammability when burned with cheatgrass were higher than expected based on the flammability of each species, suggesting that Columbia needlegrass may be susceptible to pre-heating from combustion of cheatgrass. Conversely, the flammability of bluebunch wheatgrass and cheatgrass together had both positive and negative interactive effects, suggesting the impact on joint flammability from cheatgrass differs by perennial grass species. Conclusions This study provides experimental evidence supporting previous qualitative observations of cheatgrass flammability. Cheatgrass increased perennial grass sustainability and consumption, suggesting that cheatgrass poses a significant fire threat to native grasses regardless of moisture content. The study provides species-specific insights into flammability, which could be used to inform efforts to prevent or mitigate cheatgrass-induced wildfires.

Electromagnetic–thermal–mechanical coupling analysis of bent rotor straightening via electromagnetic induction heating

Abstract Rotors of steam turbines in power plants can be locally deformed by undesired situations, such as rubbing between the rotors and stationary parts. A straightening process is required to correct bending without causing additional damage because a rotor bending displacement of approximately 0.15 mm can stop turbine unit operation. In this study, a numerical framework was established to simulate the straightening process using electromagnetic induction heating, which is straightforward and economical among the methods for straightening bent rotors. The straightening process involves complex coupling of electromagnetic, thermal, and mechanical phenomena. For efficiency, sequential coupling was used in the simulations, dividing the multiphysics phenomena into electromagnetic–thermal and thermal–mechanical fields. The temperature distributions resulting from electromagnetic induction heating were calculated through two-way coupling of the electromagnetic–thermal analysis. The thermal deformations of the rotors were obtained by solving the coupled equations for the thermal field obtained from the electromagnetic–thermal analysis and the mechanical field. Using the established numerical framework, the thermal–mechanical behaviors and straightening mechanisms of bent rotors were investigated. Furthermore, the effects of process parameters, including the direction of gravity and heating and cooling conditions, on the straightening performance were determined. Appropriate parameters were identified to achieve the desired straightening performance with final bending displacements of less than 0.1 mm for bent rotors with initial bending displacements of 0.15–0.3 mm. For a rotor made of A182 F11 Class 2, the best straightening performance was obtained by heating the rotor to a maximum temperature of 650 °C for 20 h under insulation, followed by natural cooling. The simulation results revealed that the straightening performance can be improved when the rotor is rapidly heated to a high maximum temperature and cooled immediately, as long as the temperature conditions do not cause phase transformation or unintended plastic deformation of the bent rotors.

Temperature Measurement of Ballistic Evaluation Motor Using K-Type Thermocouple

The paper presents an investigation of the burning rate of the selected solid propellant using a Ballistic Evaluation Motor (BEM) for solid-rocket propulsion study. A K-type thermocouple was used to capture the temperature of the BEM. Previous studies on BEM have been customized to specific experiments accordingly without any standardized approach for temperature measurement. Variations in the methodology have led to inconsistent and potentially unreliable results across different research efforts. The purpose of the study is to establish a more reliable and standardized method for temperature measurement in BEM by validating the temperature readings recorded by a K-type thermocouple. The scope of the study includes recording the ignition and combustion temperature of the BEM against the time. Three different propellants were used in the experiments, ammonium perchlorate with sorbitol and magnesium, potassium nitrate with sucrose, and ammonium perchlorate with sorbitol and iron (III) oxide. The results indicate that ammonium perchlorate with sorbitol gives the highest maximum temperature which is at 101℃. The other propellants, ammonium perchlorate with magnesium and potassium nitrate with sucrose, recorded maximum temperatures of 75.20 °C and 57.25 °C, respectively. The validation process confirmed the reliability of the K-type thermocouple, with an average deviation of 2.3 °C to 3.7 °C from the reference thermometer readings. A notable performance was observed for the propellant using sorbitol andammonium perchlorate with iron (III) oxide. The experiment contributes to significant findings of the solid-rocket propulsion study, hence advanced solidrocket research can be explored from here onwards.

Positive and Negative Effects of Inter‐Annual Climate Variability on Rice (Oryza sativa L.) Crop in Agro‐Climatic Zones of Punjab

ABSTRACTGlobally, climate changes have significantly shifted the phenological phases and stages of rice, altered the duration of the growing season and negatively affected rice productivity due to flooding and drought. However, in the present study, the positive and negative impacts of inter‐annual climate variability on rice crops during phenological stages in agro‐climatic zones of Punjab for the period from 1989 to 2018. Initially, first difference approach was applied to minimise the impact of technological factors. Then, skewness and kurtosis tests were used to check the normalisation of the data. The standardisation method was used to normalise the data. Pearson correlation was used to determine the significant effects of climate variables on rice yield. The residuals were formed to confirm the effects of inter‐annual climate variability on rice yield in the phenological phases. The analysis revealed that a high variability of rice yields was investigated in the western region compared to the southern and western regions. The results showed a negative impact of heavy rainfall (flooding) on the years with low yields (2010, 2013 and 2016) in the Central region. Similarly, the years with low rice yields (1996, 2010, 2013 and 2014) in the Southern region were negatively affected by flooding at the time of sowing. A positive effect of rainfall was observed in the years with high rice yields (1995, 2002, 2009 and 2018) in the Western region. In contrast, the low‐yielding years 1994, 2003 and 2010 were negatively affected by flooding in the same years during the tillering stage. A high interannual maximum temperature variability was analysed in the Southern > Western > Central regions, leading to yield losses due to biotic stress during tillering and stem elongation stages. This is due to the immense reason of drought stress. The minimum temperature negatively affects the low‐yield years (2001, 2008, 2013 and 2016) in the central zone and the low‐yield years (2014, 2015 and 2016) in the southern zone during the reproductive stage. This research will help to develop new rice varieties that are more productive at high temperatures and require less water, leading to sustainable development in arid and semi‐arid regions.

Evaluation of thermal effects of surgical energy devices: ex vivo study

This study evaluated the direct and indirect thermal effects of various surgical energy devices using an ex-vivo model. Two types of three devices were evaluated: ENSEAL™ X1 Curved Jaw Tissue Sealer (X1) and ENSEAL™ G2 Curved Tissue Sealer (G2) as vessel sealing systems (VSSs), and HARMONIC® HD1000i Shears (HA) as an ultrasonic activating device (USAD). Each device was activated once under DRY or WET conditions. The tissue’s maximum temperature (MT), steam MT surrounding the activation site, and steam spread area (SSA) were measured. Under WET conditions, the median MT of a porcine common carotid artery at 1 mm from the activation site by X1, G2, and HA were 84.4, 83.3, and 50.5 °C, respectively. The direct thermal effect of HA was the lowest among the three devices. VSSs showed higher tissue MT under WET conditions compared with DRY conditions. Conversely, USAD showed the opposite trend. G2 demonstrated a significantly higher MT than X1 and HA (P < 0.05). A significant decrease in SSA was observed with decreasing grasping range. In conclusion, VSSs generated higher temperatures than USAD, especially under WET conditions. Surgeons should consider minimizing thermal effects by creating DRY conditions or performing gradual incisions when using VSS devices.

Exploring Cool Pavement Technologies: A Lab-Based Experimental Analysis of Temperature and Reflectivity

Urban heat islands (UHI) have become an increasingly pressing issue owing to the global warming trend and a steady growth of urban areas. Revegetation, shading, or the reduction of sealed surfaces is not always possible in cities. Therefore, one way to fight UHIs is through adapting currently used pavements. This study assesses the thermal behavior of 12 different pavement materials in a custom-made test stand. The materials include mastic asphalt ( MA 8, MA 8 white), porous asphalt ( PA 4, PA 4 abraded, PA 4 white, PA 8, PA 8 abraded, PA 8 white), asphalt concrete ( AC 11 transparent, AC 8 yellow), and semi-flexible pavements ( SFP 8, SFP 8 zeolite). The albedo was assessed using pyranometer. Sensors and thermal imaging were used to measure temperatures during two simulated heat cycles. Both the temperatures underneath the test specimens and at the surface were considered, as well as the cooling times of the materials. The results showed high maximum temperatures for PA and MA, as well as low maxima for the white painted materials, with differences in maxima of up to 15°C. Porous asphalt, like PA 8, cools faster than MA 8 from roughly 47°C to 28°C, taking 3.7 h compared with MA 8’s 5.1 h. This highlights the importance of considering cooling times and regional solar phases in experimental setups. Through the wide range of tested materials, a significant linear correlation between the measured albedo and surface temperature was proven. Ultimately, a foundation for thermal comparability between these materials was established.

Integrating phase change materials in buildings for heating and cooling demand reduction – A global study

This study aims to analyse the integration of Phase Change Materials (PCMs) in building envelopes globally, focusing on its ability to reduce the energy demand and its economic viability. The study conducted extensive simulations using the DesignBuilder software across 5684 locations globally and utilising artificial intelligence (AI) models to extend the simulation further to 73,515 locations, evaluating the impacts of PCM properties such as melting temperature (MT) and thickness. The main findings indicate that pronounced annual energy savings, 2500 to 3000 kWh, are observed in equatorial regions including northeast Brazil, central Africa, and the Malay Archipelago. Additionally, the optimal utilisation of increased PCM thickness is contingent upon selecting the correct MT and is most effective in regions with high average maximum temperatures, while the most common effective thickness is 20 mm. The study demonstrates that MT significantly affects energy savings, more than PCM thickness, highlighting the importance of selecting appropriate MT based on climatic conditions. The 25 °C MT is most effective within lower latitude range (−15°–30°), averaging 743.2 kWh greater savings than the 21 °C option. The 21 °C MT shows superior performance outside of this range, however the advantage is marginal as the average savings is 251.0 kWh. Economically, regions such as the USA, southern Europe (Spain and Italy), Brazil, and northern Australia show the best viability for PCM integration, aligning energy efficiency improvements with substantial economic returns. This comprehensive analysis suggests that tailored PCM integration strategies are essential for maximising energy savings and advancing sustainable building practices.

Spatiotemporal analysis of land use and land cover changes, LST and NDVI in Thatta district, Sindh, Pakistan

The purpose of this work is to determine land-use and land-cover (LULC) patterns, land surface temperature (LST), and normalized difference vegetation index (NDVI) changes in Thatta district using Landsat data from 1991 to 2021 and evaluate the relationship between LST and NDVI. The research process employed the selection of the study area, data acquisition, preprocessing, and classification of remotely sensed images for the estimation of the land use land cover change (LULC), vegetation index (NDVI), and evaluation of LST using thermal bands in the Landsat dataset. The study revealed the area under built-up structures has increased from 1991 to 2021. Although the vegetation cover showed an increase, the bare soil showed a decreasing pattern, indicating a constant change in the LULC patterns in the region. The confusion matrix method for accuracy valuation of LULC data of 2021 revealed an overall accuracy of 88.24%, with a Kappa coefficient of 84.22%, while the Artificial Neural Network Multilayer Perceptron (ANN-MLP) model had a Kappa validation of 0.95 for 2021. The highest maximum temperature is observed for 2021, indicating a positive relationship between LST and built-up structures, while regression analysis found a negative correlation between LST and NDVI. This study provides a valuable monitoring framework to help resource managers develop strategies to manage land resources.

Mediating Effect of the Stay-at-Home Order on the Association between Mobility, Weather, and COVID-19 Infection and Mortality in Indiana and Kentucky: March to May 2020

(1) Background: The association of COVID-19 infection and mortality with mobility and weather in Indiana and Kentucky was compared for the period from 1 March to 15 May 2020. (2) Methods: The risk of COVID-19 infection and mortality was evaluated using Cox regressions with the following covariates: mobility (retail/recreation, grocery/pharmacy, and workplace), weather (precipitation, minimum and maximum temperature, ultraviolet [UV] index), and metropolitan status. (3) Results: A higher maximum temperature (adjusted hazard ratioinfection (aHRi) = 1.01; adjusted hazard ratiodeath (aHRd) = 1.001), metropolitan status (aHRi = 1.12; aHRd = 2.05), and a higher minimum temperature (aHRi = 1.01) were associated with increased risks of COVID-19 infection and/or mortality. Protection against COVID-19 infection and/or mortality was associated with retail/recreation (aHRi = 0.97; aHRd = 0.937), grocery/pharmacy (aHRi = 0.991; aHRd = 0.992), workplace (aHRi = 0.99; aHRd = 0.965), precipitation (aHRi = 0.999; aHRd = 0.9978), UV index (aHRi = 0.37; aHRd = 0.748), and a higher minimum temperature (aHRd = 0.994). COVID-19 infection (aHRi = 1.18) and mortality (aHRd = 1.59) risks were higher in Indiana compared to Kentucky. (4) Conclusions: COVID-19 infection and mortality were 18% and 59% more likely among Indiana residents compared to Kentucky residents, respectively. This may be attributed to variations in stay-at-home order compliance and enforcement between Indiana and Kentucky.

Consequences of thermal aging on the detection of impact damage in composite structures with PZT/FBG guided wave systems

In the context of recent reusable launch vehicles (RLV) developments, SHM could help fast and economic revalidation of RLVs between launches, provided that the transducers keep their functionality and reliability after repeating launches being exposed to harsh flight conditions. This paper studies the detection of barely visible impact damage in composite plates with guided waves (GW) based SHM systems. More precisely, it focuses on how this detection can be affected by the degradation of the sensors potentially induced by the exposition to flight conditions. The aging conditions in this work mainly consist of thermal cycling with high maximum temperature (150°C), expected for RLV structures and close to the operational limit of the thermoset-matrix composite. The response of the sensors to such environmental conditions depends on the sensor itself and on its bonding to the structure. Thus, in this paper two different types of sensors are tested (commonly used PZT transducers and FBG sensors) along with two different bonding methods (classic bonding with a secondary adhesive and cobonding on composite surface during the curing process). The sensors are setup in pairs (PZT-PZT or PZT-FBG) with GW signal paths going through the impact location. After a baseline acquisition, incremental impact tests (with increasing energy) are performed and GW signals are acquired after each impact to assess the damage signature on the waveform. Then after submitting the plate to thermal cycling, GW signals are recorded again to assess its effect on the damage detection performance and on the risk of false alarms (mistaking sensor degradation for structural damage). Sensor degradations are monitored through non-destructive techniques and impedance self-diagnostic measurements for PZT. Additionally to this aging test, the responses of degraded sensors previously studied by the authors are compared with the impact signature to assess how those degraded sensors could harm the impact detection.

Compounded wind gusts and maximum temperature via semiparametric copula in the risk assessments of power blackouts and air conditioning demands for major cities in Canada

A semiparametric copula joint framework was proposed to model wind gust speed (WGS) and maximum temperature (MT) in Canada, using Gaussian kernel density estimation (GKDE) with parametric copulas. Their joint probability estimates allow for a better understanding of the risk of power blackouts and the demand for air conditioning in the community. The bivariate framework used two extreme sample groups to define extreme pairs at different time lags, i.e., 0 to ± 3 days, annual maximum WGS (AMWGS) and corresponding MT and annual highest MT (AHMT) and corresponding WGS. A thorough model performance comparison indicated that GKDE outperformed the parametric models in defining the marginal distribution of selected univariate series. Significant positive correlations were observed among extreme pairs, except for Calgary and Halifax stations, with inconsistent correlation variations based on selected cities and lag time. Various parametric 2-D copulas were selected to model the dependence structure of bivariate pairs at different time lags for selected stations. AMWGS or AHMT events, when considered independently, would be stressful for all stations due to high estimated quantiles with low univariate RPs. The bivariate events exhibited lower AND-joint RPs with moderate to high design quantiles, indicating a higher risk of power blackouts and heightened air-conditioning demands, which varied inconsistently with time lags across the station. The bivariate AMWGS and corresponding MT events would be stressful in Regina, Quebec City, Ottawa, and Edmonton, while AHMT and corresponding WGS events in Toronto, Regina, and Montreal. Conversely, Vancouver poses a lower risk of joint action of pairs AHMT and corresponding WGS events. These hazard statistics can help in better planning for community well-being during extreme weather.

Acetaminophen and Ibuprofen in Pediatric Central Nervous System Malaria

A third of children who survive malaria with neurological involvement (central nervous system [CNS] malaria) develop sequelae. A higher maximum temperature (Tmax) and seizures are risk factors for sequelae. To compare aggressive antipyretic therapy using scheduled acetaminophen and ibuprofen vs usual care with acetaminophen alone given only for a temperature of 38.5 °C or higher. This randomized clinical trial was conducted at inpatient pediatric services of 1 tertiary care and 1 district hospital in Zambia and a tertiary care center in Malawi. Included were children aged 2 to 11 years with CNS malaria (excluding those with creatinine >1.2 mg/dL), who were enrolled from 2019 to 2022. Data analysis took place from December 2022 to April 2023. The aggressive antipyretic group received acetaminophen (30 mg/kg load, then 15 mg/kg) plus ibuprofen, 10 mg/kg, every 6 hours, regardless of clinical temperature for 72 hours. The usual care group received 15 mg/kg of acetaminophen as needed every 6 hours for a temperature of 38.5 °C or higher. The primary outcome variable was Tmax over 72 hours, the total duration of follow-up. Secondary outcomes included seizures and parasite clearance. Five hundred fifty-three patients were screened, 226 (40.9%) were ineligible, and 57 (10.3%) declined. A total 256 participants (n = 128/group) had a mean (SD) age of 4.3 (2.1) years; 115 (45%) were female, and 141 (55%) were male. The aggressive antipyretic group had a lower Tmax, 38.6 vs 39.2 °C (difference, -0.62 °C; 95% CI, -0.82 to -0.42; P < .001) and lower odds of experiencing multiple or prolonged seizures, 10 (8%) vs 34 children (27%) in the usual care group (odds ratio [OR], 0.26; 95% CI, 0.12 to 0.56). No group difference in parasite clearance time was detected. Severe adverse events occurred in 40 children (15%), 25 (20%) in the usual care group and 15 (12%) in the aggressive antipyretic group, including 13 deaths (10 [8%] and 3 [2%], respectively). Increased creatinine resulted in study drug discontinuation in 8 children (6%) in the usual care group and 13 children (10%) in the aggressive antipyretic group (OR, 1.74; 95% CI, 0.63 to 5.07). This study found that aggressive antipyretic therapy reduced mean Tmax to temperature levels comparable with the Tmax among children without neurological impairments in prior observational studies and improved acute seizure outcomes with no prolongation of parasitemia. ClinicalTrials.gov Identifier: NCT03399318.

Performance analyses on the air cooling battery thermal management based on artificial neural networks

Air cooling thermal management technology is a lightweight and cost-effective approach for managing heat in power battery packs for electric ships. However, it suffers from significant drawbacks such as poor temperature control and excessive noise generation. To address these challenges, this study proposes a method that combines fluid dynamics and artificial neural networks (ANNs) to optimize the thermal management and aeroacoustic performance of the air cooling battery thermal management system (BTMS) for marine power batteries. Initially, a thermal-flow coupled model and an acoustic model for the BTMS were developed to investigate the impact of system structural parameters (battery spacing d, and main channel inclination angle θ) and operating parameter (system inlet velocity v) on the thermal management performance indicators (maximum temperature Tmax, and maximum temperature difference ΔTmax) as well as the aeroacoustic performance indicator (overall sound pressure level, OSPL). Subsequently, a relationship between the system structural and operating parameters and performance indicators was established using the 50-layer Residual Network (ResNet-50) model, enabling accurate and rapid prediction of the system thermal management and aeroacoustic performance. Furthermore, by combining ResNet-50 with the evaluation method of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), this study successfully obtained the optimal system structure and operating parameters. The research indicates that keeping the remaining parameters constant, increasing the battery spacing results in higher maximum temperature and maximum temperature difference, while decreasing the overall system sound pressure level. Conversely, increasing the main channel inclination angle results in lower maximum temperature and maximum temperature difference, but higher overall system sound pressure level. In addition, increasing the inlet velocity will result in higher maximum temperature and maximum temperature difference, as well as higher overall system sound pressure level. The optimal case were found to be a main channel inclination angle θ = 3°, battery spacing d = 2 mm, and inlet velocity v = 10 m⋅s−1. Compared to the base case, the optimal case shows a maximum temperature reduction of 10.63 K, a maximum temperature difference reduction of 9.41 K, and an overall sound pressure level reduction of 4.6 dB. The prediction errors for these values are 0.08 %, 2.64 %, and 1.36 % respectively. This research demonstrates an effective and rapid approach based on fluid dynamics and ANNs in the design and optimization of BTMS.

Association between left atrial wall thickness and residual potential after first-pass pulmonary vein isolation using very high-power short-duration ablation in patients with atrial fibrillation

Abstract Background In this study, we evaluated efficacy, efficiency, and safety of pulmonary vein isolation (PVI) applying vHPSD ablation strategy in patients with atrial fibrillation (AF) and explored the association between left atrial wall thickness (LAWT) and the residual potential after first-pass PVI. Methods Between April 2, 2023 and October 6, 2023, drug refractory symptomatic AF patients who underwent AF ablation using vHPSD ablation strategy with QDOT MICRO catheter were prospectively enrolled. All patients took cardiac computed tomography (CT) a day before procedure. Using CT image, LAWT map was created. PV segments were categorized into prespecified 14 segments, and LAWT of each segment, segments with residual potential (RP) after first-pass PVI and early reconnection after 20-minute waiting after PVI were evaluated. Total procedure time, ablation time for PVI, and occurrence of procedure-related complication were collected. Results A total of 40 patients were included (mean age 64 years, 45% of persistent AF). Additional ablation other than PV was performed in 48% of patients, total procedure time was 77 minutes, and total PVI time was 9.9 minutes. With vHPSD PVI, all PVs first pass isolation rate was 60%; in terms of per PV, RSPV first-pass isolation was 88%, followed by LSPV and LIPV 85%, RIPV showed lowest first-pass isolation rate, 75% (Figure A). Most common RP sites was right carina, followed by left carina (Figure A). Compared to historical comparator, vHPSD PVI showed shorter procedure time, shorter ablation time for PVI, with numerically lower but statistically comparable first-pass PVI rate (Figure B). In total 560 PV segments in 40 patients, RSPV anterior, left carina, and right carina showed higher prevalence to be thick PV segments (over 60% of patients), followed by RPSV posterior, LSPV posterior, and RIPV anterior (over 40% of patients). Looking into ablation parameter detail, mean contact force was 10g, mean temperature was 47°C, and mean impedance drop was 8.4Ω. Compared to segments without RP, segments with RP showed thicker mean left atrial wall thickness grades, lower minimum contact force, higher maximum temperature, and lower minimum impedance drop. According to the left atrial wall thickness, thick PV segments showed higher prevalence of RP after first-pass PVI with vHPSD ablation. In segments with LAWT grade 3 or more, the RP rate was 9.1%. This thickness means thicker than 1.5 to 2.0 mm of thickness (Figure C). In 10% of patients (n=4) had audible or tactile steam-pops, visible char was confirmed in 5% of patients (n=2). There were no clinical complications. Conclusion PVI using vHPSD achieved shorter procedure time, shorter ablation time for PVI, and comparable first-pass PVI rate compared to historical comparator using ablation-index guided conventional power ablation. Thick segments had higher chance to have residual potential after first-pass PVI with vHPSD.

Clinical features of COVID-19 in children with a chronic adenotonsillar disorder

BACKGROUND: COVID-19, caused by SARS-CoV-2, is a highly contagious infectious disease associated with a risk of severe complications. In Russia, the COVID-19 incidence has exceeded 24 million, with new strains raising the incidence in children up to 18%. The prevalence of long COVID is rising. In children, the adaptive immune system, including the lymphoepithelial ring of the throat, plays a key role in determining the severity of COVID-19. The lymphoid tissue of the Waldeyer’s ring is one of the first immune barriers against coronaviruses and other respiratory infections. The high incidence of co-infection worsens the course of the disease. A chronic adenotonsillar disease has incidence of 32%–35% in children. However, impact of this disease on the severity of COVID-19 and the incidence of co-infection in children is poorly understood. AIM: The aim of the study was to evaluate impact of the chronic adenotonsillar disease on COVID-19 progression and the incidence of co-infections in children. MATERIALS AND METHODS: Conducted in St. Petersburg from January 2022 to March 2023, the study included 493 children (300 with COVID-19 and 144 with chronic adenotonsillar disease). Patients were divided into four groups to evaluate impact of chronic adenotonsillar disease on COVID-19 progression. Non-parametric statistical methods were used to analyze the clinical data. RESULTS: Children with both COVID-19 and chronic adenotonsillar disease demonstrated a more severe course of disease compared to those without chronic adenotonsillar disease. The first group showed an increased incidence of bronchitis, bacterial co-infections, longer hospitalization and disease duration, longer fever duration, and higher maximum temperature. Laboratory data showed higher white blood cell counts in patients with COVID-19 and chronic adenotonsillar disease compared to those without chronic adenotonsillar disease. CONCLUSIONS: Chronic adenotonsillar disease significantly complicates the course of COVID-19 in children. Further research is needed to elucidate the pathophysiological mechanisms and optimize treatment strategies for children with chronic adenotonsillar disease.

Changes in Fingertip Cold-Induced Vasodilatation (Hunting Reaction) on Acute Exposure to Altitude.

Fossati, Alexandre, and Aleid C. J. Ruijs. Changes in fingertip cold-induced vasodilatation (hunting reaction) on acute exposure to altitude. High Alt Med Biol. 25:212-217, 2024. Objective: Cold-induced vasodilation (CIVD) of the extremities is an interesting part of human physiology. Although the physiology of the CIVD reaction remains unknown, there are indications that hypoxia influences our CIVD reaction. The objective of this study is to measure the influence of acute hypoxia on the CIVD reaction of the fingertips. Methods: The CIVD reaction was measured using immersion of one hand in a water bath of 0°C in 12 healthy volunteers at low (1,235 m) and high (3,800 m) altitude during 35 minutes. High altitude was reached by a 20-minute cable car ride. Testing was performed indoors (room temperature, 22-25°C) at both altitudes. Data analysis was performed measuring the parameters of the CIVD reaction. Differences were found using the paired Student's t-test. Results: There was no significant difference in baseline finger temperature, onset time, peak time, and frequency of the CIVD reaction. However, at high altitude, maximum temperature and amplitude were significantly higher, slope was steeper, and minimum temperature was lower. Conclusion: We did not find evidence for a diminished CIVD reaction at high altitude due to hypoxia.

Temporal Clustering of Precipitation Driving Landslides Over the Italian Territory

AbstractThe occurrence of multiple precipitation events not‐independent in time, that is, a temporal clustering, is an example of a temporal compounding event. This type of forcing is of great relevance for the occurrence of different natural hazards, like floods and deep‐seated landslides, for which previous soil saturation plays an important role in shaping the associated hazard. Using ERA5‐Land data set and E‐OBS, we firstly investigate the spatial and temporal characteristics of temporal clustering of precipitation over the Italian territory, and we relate it with two oscillation patterns, namely North Atlantic Oscillation (NAO) and Mediterranean Oscillation Index (MOI), and with common synoptic conditions. Then, we explore the role of temporal compounding of precipitation in the generation of different movement types (complex, debris flow, fall, flow, and sliding) using the database of landslides from the Aree Vulnerate Italiane project (in Italian AVI, meaning Areas Affected by Landslides or Floods). From this study it emerges that below average values of NAO and MOI increase the probability of having clustered precipitation events. For all types of landslides, except rock falls, we observed that the majority of the events are preceded by a temporal clustering of precipitation, over longer time windows for complex events, shorter for debris flows. For rock falls, we found also a link with low minimum temperature and freeze‐thaw cycles for winter events and high maximum temperature for summer events. This work contributes to the investigation of temporal clustering of precipitation in connection with natural hazards characterized by a mechanism of saturation.