Change In Distance Research Articles

Temporal change of land cover and distance to nature (D2N) to diagnose the anthropogenic influence on two watersheds in the southeastern region of Brazil.

Watersheds are highly complex aquatic systems crucial to human and ecological functions. Land cover impacts watersheds, and assessing the landscape structure and configuration is essential for effective management and planning, mainly when using indicators of anthropogenic disturbances such as distance to nature (D2N). This study aimed to assess the temporal change in land cover and anthropogenic influence in the Piracicaba Capivari Jundiaí Watershed (WPCJ) and the Sorocaba Médio Tietê Watershed (WSMT) in southeastern Brazil from 2010 to 2020, providing valuable information for decision-making. In both watersheds, agricultural activities predominated, covering more than 60% of the area, with forestry being dominant in 2010 and sugarcane in 2020. However, forest areas have increased in both study regions. The D2N analysis indicated a predominance of urbanized or intensively cultivated landscapes (> 60%). There was an improvement in 2020 compared to 2010, attributed to increased natural areas. Regarding the temporal change in D2N, more areas transitioned toward artificial rather than natural states in both WPCJ and WSMT, although a considerable portion remained unchanged (> 75%). This analysis is one of the few that applies D2N to watershed assessment. We emphasize the need for continued planning and conservation efforts in the WPCJ and WSMT and the potential for using this approach to assess anthropogenic influence in other watersheds.

Sensitivity of radiometric results for a Lambertian source to simple changes of geometry

Abstract This work considers the effects of changes in distance, centering and tilting of optical elements on radiometric throughput. Analytical formulas for leading-order effects are compared to numerical calculations for validation purposes.

Molecular dynamics study on the edge effect of single crystal Ni with two indenters nanoindentation

The edge effect and the formation and evolution of dislocations in nanoindentation were studied using molecular dynamics methods. A series of molecular dynamics models of two indenter nanoindentation was constructed, and diamond indenters were used for indentation simulation. This paper analyzes the effects of two indenters distance and indentation depth on the edge side extrusion, surface collapse, indentation force, internal defects, and stress of single crystal Ni workpieces. The results show that the number of particles extruded from the side does not increase linearly with the indentation distance increasing, the magnitude of indentation force changes with the increase of indentation depth and is influenced by the distance between the indenters, and the internal defects of single crystal nickel workpieces change with the change of indentation distance and increase with the increase of indentation depth. This work has a positive impact on understanding the nanoindentation processing of single crystal Ni and can help to understand the mechanism of internal dislocation formation in workpieces under multiple indenters indentation.

The Protocol for the Multi-Ethnic, multi-centre raNdomised controlled trial of a low-energy Diet for improving functional status in heart failure with Preserved ejection fraction (AMEND Preserved)

IntroductionHeart failure with preserved ejection fraction (HFpEF) is characterised by severe exercise intolerance, particularly in those living with obesity. Low-energy meal-replacement plans (MRPs) have shown significant weight loss and potential...

Dual balanced readout for scattered light noise mitigation in Michelson interferometers

Ground-based gravitational wave detectors use laser interferometry to detect the minuscule distance change between test masses caused by gravitational waves. Stray light that scatters back into the interferometer causes transient signals that can cover the same frequency range as a potential gravitational wave signal. This scattered light noise is a potentially limiting factor in current and future detectors thus making it relevant to find new ways to mitigate it. Here, we demonstrate experimentally a technique for the subtraction of scattered light noise from the displacement readout of a Michelson interferometer. It is based on using a balanced homodyne detector at both the symmetric and the antisymmetric port. While we have been able to demonstrate a noise reduction of 13.2 dB, the readout scheme seems to be only limited by the associated noise couplings, i.e., shot noise and the coupling of laser noise. We also discuss challenges for using the dual balanced homodyne detection scheme in more complex interferometer topologies, which could lead to improvements in scattered light noise mitigation of gravitational wave detectors. Published by the American Physical Society 2025

Changes in interpersonal distance modulate social attention engagement: Evidence from EEG alpha band suppression.

Interpersonal space is regulated carefully and updated dynamically during social interactions to maintain comfort. We investigated the naturalistic processing of interpersonal distance in real time and space using a powerful implicit neurophysiological measure of attentional engagement. In a sample of 37 young adults recruited at a UK university, we found greater EEG alpha band suppression when a person occupies or moves into near personal space than for a person occupying or moving into public space. In the dynamic condition only, the differences attenuated over the course of the experiment, and were sensitive to individual differences in social anxiety. These data show, for the first time, neurophysiological correlates of interpersonal distance coding in a naturalistic setting. Critically, while veridical distance is important for attentional response to the presence of a person in one's space, the behavioural relevance of their movement through public and personal space takes primacy.

A Systematic Study of the Structural Properties of Technical Lignins.

Technical lignins are globally available and a sustainable feedstock. The unique properties of technical lignins suggest that these materials should have several industrial applications. The main proposal of this study is to evaluate the relationship between the structure and properties of two technical lignins. Morphological, chemical, physical, and thermal properties of sodium lignosulfonate (LGNa) and magnesium lignosulfonate (LGMg) were investigated. The results showed that a higher formation of intramolecular hydrogen bonds may occur in lignins with a higher content of phenolic hydroxyl groups, such as LGMg. As a result, an increase in the energy of hydrogen bonds in the lignosulfonate structure was observed, without significant change in the hydrogen bond distances. In addition, higher content of phenolic hydroxyl groups might also reduce lignosulfonates thermal stability. The combustion index value was three times higher for LGMg than for LGNa. The characterization study also revealed that phenolic hydroxyl groups influence the main properties of technical lignins and can be a determining factor when these lignosulfonates are used in industrial applications.

Simulation of clinical trials of oral treprostinil in pulmonary arterial hypertension using a virtual population

Challenges in drug development for rare diseases such as pulmonary arterial hypertension can be addressed through the use of mathematical modeling. In this study, a quantitative systems pharmacology model of pulmonary arterial hypertension pathophysiology and pharmacology was used to predict changes in pulmonary vascular resistance and six-minute walk distance in the context of oral treprostinil clinical studies. We generated a virtual population that spanned the range of clinical observations and then calibrated virtual patient-specific weights to match clinical trials. We then used this virtual population to predict the results of clinical trials on the basis of disease severity, dosing regimen, time since diagnosis, and co-administered background therapies. The virtual population captured the effect of changes in trial design and patient subpopulation on clinical response. We also demonstrated the virtual trial workflow’s potential for enriching populations based on clinical biomarkers to increase likelihood of trial success.

Effects of Acute Phase Intensive Exercise Training in Patients With Acute Decompensated HeartFailure.

Acute decompensated heart failure (ADHF) leads to hospitalizations and functional decline in older adults. Although cardiac rehabilitation (CR) is effective for stable heart failure, its impact on ADHF patients, particularly those without frailty, is unclear. The goal of this study was to evaluate the efficacy and safety of early in-hospital CR for patients hospitalized with ADHF who are not frail. In this multicenter trial (ACTIVE-ADHF [Effects of Acute Phase Intensive Exercise Training in Patients with Acute Decompensated HeartFailure]), ADHF patients without physical frailty were randomized 2:1 to undergo either exercise-based CR or standard care. The intervention included early mobilization and structured exercise training. The primary outcome was the change in 6-minute walk distance (6MWD) from baseline to discharge. Secondary outcomes assessed physical and cognitive function, quality of life, and safety. A total of 91 patients were randomized to treatment, with 59 allocated to the intervention group and 32 to the control group. The primary outcome, 6MWD, improved significantly more in the intervention group, with a mean increase of 75.0 ± 7.8m vs 44.1 ± 10.2m in the control group, with an effect size of 30.9 ± 13.1m (95%CI: 4.8-57.0; P= 0.021). The intervention group showed favorable results in secondary efficacy outcomes, including physical and cognitive function, physical activity, and quality of life. Safety outcomes were similar between groups, except for a greater reduction in B-type natriuretic peptide levels at 90days' postdischarge in the intervention group. In patients with ADHF without physical frailty, in-hospital exercise-based CR led to significant improvements in 6MWD at 2weeks after randomization without compromising safety. (ACTIVE-ADHF [Effects of Acute Phase Intensive Exercise Training in Patients with Acute Decompensated HeartFailure]; UMIN000020919).

Left Ventricular Assist Device Therapy in Cold and Dry Patients.

Patients with end-stage heart failure and low pulmonary capillary wedge pressure are referred to as cold and dry and represent an understudied minority in whom the benefit of left ventricular assist device (LVAD) therapy is unclear. Adults receiving LVADs between 2006 and 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support database were classified as cold and wet (pulmonary capillary wedge pressure >15 mm Hg) and cold and dry (pulmonary capillary wedge pressure ≤15 mm Hg) based on pre-LVAD hemodynamics obtained via right heart catheterization. The primary outcome was 1-year survival. Secondary outcomes were rehospitalizations, change in 6-minute walk test distance, change in Kansas City Cardiomyopathy Questionnaire, and change in EuroQol questionnaire scores 1 year after LVAD. Our study included 10 310 patients with complete clinical, echocardiographic, and functional capacity profiles. The median follow-up was 364 days (interquartile range, 326-381 days). Overall, the mean pulmonary capillary wedge pressure before LVAD implantation was 25±9 mm Hg. Cold and dry patients comprised 15% of the cohort and were more frequently female, had smaller mean body size, smaller mean left ventricular size, and better mean baseline renal function. Compared with cold and wet patients, cold and dry patients also had better baseline functional capacity and quality of life and experienced milder improvements after LVAD: EuroQol (+0.11 versus +0.17; P=0.001), Kansas City Cardiomyopathy Questionnaire (+26 versus +31; P=0.031), and 6-minute walk test distance (+194 feet versus +340 feet; P=0.026). There was no statistically significant difference between the rate of hospitalizations (P=0.76), adverse events, and mortality (log-rank P=0.81) at 1 year between the 2 groups. In cold and dry patients with end-stage heart failure, LVADs are associated with milder but significant improvements in functional capacity and quality of life with a similar incidence of adverse events and survival at 1 year.

Feasibility of a virtual multimodal prehabilitation intervention for patients with cancer undergoing surgery.

Current prehabilitation programs are often limited by poor recruitment and attrition rates. Remote delivery of prehabilitation may reduce barriers to participation and maximize program retention. We aimed to assess the feasibility (uptake, retention, fidelity), preliminary effectiveness, and acceptability of delivering a technology-supported prehabilitation program remotely to oncologic surgical candidates. This was a one-arm pragmatic feasibility study aiming to follow patients for 4-6 weeks preoperatively and 8 weeks postoperatively. All patients received a home-based aerobic and resistance exercise program, with psychosocial counselling as needed. Those at risk of malnutrition received nutritional counselling and supplements to meet personalized energy and protein targets. Adherence was assessed using an exercise watch and a mobile application for dietary assessment. In addition, we assessed physical effects, with change in 6-min walking distance of 20m defined as clinically meaningful recovery, and post-operative complications. Acceptability was assessed using a convergence mixed-methods approach. A total of 28 participants were included (median 69, IQR 9.5 years; 12/28, 43% males). Rate of recruitment was 47%, retention was 78%, and attendance was 86-93%. Participants walked an average of 8168 (SD: 4685) steps per day preoperatively and 6809 (SD: 4819) steps per day postoperatively. They consumed on average 21.6kcal/kg of ideal body weight (IBW) and 1.1g protein/kg IBW during the first week of the intervention. Participants demonstrated significant improvements in remote physical tests before surgery (arm strength:+9.7 [5.7, 13.6] repetitions in arm curl, p<0.001; leg strength:+3.2 [1.4, 4.9] sit-to-stand repetitions in 30s, p=0.001; endurance:+19.4 [12.7, 26.1] repetitions in the 2-min step test, p<0.001). The majority (16/22, 73%) achieved clinically meaningful recovery at 8 weeks postoperatively. All participants attested to the acceptability of exercising with remote supervision. A technology-assisted prehabilitation program delivered remotely is feasible and could lead to physical benefits for a surgical cancer population.

Effect of famotidine on outcomes in pulmonary arterial hypertension: A randomized controlled trial.

Adaptation of the right ventricle is a key determinant of outcomes in pulmonary arterial hypertension (PAH). Despite a compelling rationale to develop targeted therapies for the right ventricle in PAH, no such treatments exist. H2-receptor antagonism is a potential myocardial-focused paradigm in heart failure. Do H2-receptor antagonists improve outcomes in participants with PAH? We conducted a 24-week, single-center, 1:1 randomized, double-blind, placebo-controlled trial of the H2-receptor antagonist famotidine in patients with a diagnosis of PAH. The primary outcome was change in six-minute walk distance (6MWD) at 24 weeks. Secondary endpoints included B-type natriuretic peptide levels, NYHA functional class, right ventricular parameters, health-related quality of life, and escalation in PAH-focused care. From May 2019 to July 2023, 80 participants were randomized with 79 receiving study drug. There was no significant difference in the primary outcome of 6MWD at 24 weeks, with an increase of 4.7 meters seen in the placebo arm versus a decrease of 17.0 meters in the famotidine arm (p = 0.24). There were also no differences in secondary endpoints at 24 weeks. Study drug was well tolerated, and safety profiles were similar between arms. Adherence and study conduct was good overall. Participants with methamphetamine-associated PAH were similar in all aspects to the study participants more broadly. The results of this trial do not support the routine use of famotidine 20 mg daily as an adjunct therapy for the treatment of PAH. The REHAB-PH trial argues against the practice of avoiding participants with methamphetamine-associated PAH in randomized clinical trials of novel therapies. The trial was registered at clinicaltrials.gov (NCT03554291).

Investigation of Electron-Positron Pair Production in Vacuum Induced by Spatially Separated Dual Oscillating Fields

This study investigates the combination of two not completely overlapping oscillating fields. The aim is to analyze the effect of the separation distance between the fields on the production of electron-positron pairs in a vacuum.The process was simulated using Computational Quantum Field Theory (CQFT) methods and the split-operator technique, based on the space-time dependent Dirac equation. The primary focus was on analyzing the impact of separation distance and frequency combinations on the pair production rate and energy spectrum.&lt;br&gt; The research found that partially overlapping subcritical oscillating fields can still effectively generate electronpositron pairs within a small separation distance. The variation in separation distance in the overlapping direction significantly affects the pair production rate. For two oscillating fields with a fixed sum of frequencies, the separation distance has a notable impact on the production rate, with different frequency combinations showing varying degrees of dependency.&lt;br&gt;Further analysis of the energy spectrum revealed that the number and position of spectral peaks are differently affected by the separation distance. Models with smaller frequency differences exhibited more concentrated energy distributions, generally presenting a single-peak structure. In contrast, models with larger frequency differences showed more dispersed energy distributions, typically presenting a dual-peak structure. As the separation distance increases, the energy spectrum structure varies with different frequency combinations, especially for larger separation distances. In cases with larger frequency differences, the high-energy peak decreases rapidly with increasing separation distance, resulting in a lower proportion of high-energy electrons, whereas the cases with smaller frequency differences exhibit less change. This phenomenon was further analyzed using particle energy transition probability distribution diagrams.&lt;br&gt;By observing the particle energy transition probability distribution diagrams, we gained preliminary insights into the differences in various frequency combinations with changes in separation distance, explaining the variations in energy spectrum structure from the perspective of multiphoton transitions.Additionally, a more detailed analysis of these diagrams based on the law of energy conservation allowed us to extract the trends in particle production corresponding to various multiphoton transition effects.It was found that for the same frequency combination, the trends of second and third-order effects with varying separation distances differ, with higher-order effects decreasing more rapidly.&lt;br&gt;By analyzing the changes in multiphoton transition probabilities for the combined fields with separation distance, as well as the changes in the individual fields’ multiphoton transition probabilities, we concluded that when the separation distance is small, the combined fields with larger frequency differences have an advantage in electron-positron pair production. However, when the separation distance is large, the combined fields with smaller frequency differences begin to play a major role due to their inherent multiphoton effects, demonstrating better stability. For different cases under the combined influence of two fields, we conducted a more in-depth analysis of the differences between various orders within the same frequency combination and the differences between the same order transitions under different frequency combinations. By proposing hypotheses and performing computational verification, it was found that the trend of normalized-overlapping photon numbers with varying separation distances under the same conditions is consistent with the trend of corresponding particle production numbers, providing a more convenient method for examining the trends in particle production with separation distance.&lt;br&gt;This study not only enriches our understanding of vacuum electron-positron pair generation in strong fields but also provides theoretical guidance and reference for designing experimental setups for pair production.

Unlocking insights: Clinical associations from the largest 6-minute walk test collection via the my Heart Counts Cardiovascular Health Study, a fully digital smartphone platform.

The six-minute walk test (6MWT) is a prognostic sub-maximal exercise test used clinically as a measure of functional capacity. With the emergence of advanced sensors, 6MWTs are being performed remotely via smartphones and other devices. The My Heart Counts Cardiovascular Health Study is a smartphone application that serves as a digital platform for studies of human cardiovascular health, and has been used to perform 30,475 6MWTs on 8922 unique participants. As our 30,475 6MWTs represent the largest such collection of data available, we sought to identify associations with measured demographic and clinical variables with 6MWT distance at enrollment and separately determine if use of the My Heart Counts smartphone application led to changes in 6MWT distance. We present the public data release of our 30,475 6MWTs and the launch of a webpage-based data viewer of summary-level statistics, to compare the functional capacity of an individual by their age, gender, height, weight, and disease status (https://mhc-6mwts.streamlit.app). Using multivariable regression, we report associations of demographic and clinical variables with baseline 6MWT distance (N = 3606), validating prior associations with age, male gender, height, and baseline physical activity level with 6MWT distance. We also report associations of 6MWT baseline distance with employment status (+12.4 m ±4.9 m, P = 0.011) and feeling depressed (-3.65 m, ±0.79 m, P < 0.001). We separately found that cardiovascular disease status was significantly associated with decreased 6MWT distance for atrial fibrillation (-24.9 m ±7.8 m, P = 0.0013), peripheral artery disease (-41.7 m ±12.5 m, P < 0.001), and pulmonary arterial hypertension (-76.3 m ±24.8 m, P = 0.0022). Heart failure was associated with decreased 6MWT distance but was not statistically significant (-25.5 m ±14.5 m, P = 0.078). In a subset of participants who conducted repeat 6MWTs separated by at least 1 week but no greater than 3 months (N = 1129), we found that use of the My Heart Counts app was associated with a statistically significant increase in 6MWT distance (+17.5 m ±7.85 m, P < 0.001). We validate previously identified associations from clinic-performed 6MWTs, demonstrating the utility of a mobile method in collecting 6MWT data for clinicians and researchers. We also demonstrate that use of the My Heart Counts app is associated with small, but significant increases in 6MWT distance. Given the importance of 6MWTs in assessment of functional capacity, our publicly-available data will serve an important purpose as a health and disease-specific reference for investigators worldwide.

HEPATOCYTE GROWTH FACTOR FOR WALKING PERFORMANCE IN PERIPHERAL ARTERY DISEASE.

VM202 is a plasmid encoding two isoforms of hepatocyte growth factor (HGF). In preclinical studies, HGF stimulated angiogenesis and muscle regeneration. This preliminary clinical trial tested the hypothesis that VM202 injections in gastrocnemius muscle would improve walking performance in people with mild to moderate and symptomatic lower extremity peripheral artery disease (PAD). In a double-blind clinical trial, people with PAD were randomized to gastrocnemius muscle injections of either 4 mgs of VM202 or placebo every 14 days for four doses. The primary outcome was 6-month change in 6-minute walk distance. Secondary outcomes included 3-month change in treadmill walking time and gastrocnemius muscle biopsy measures. In this preliminary trial, statistical significance was pre-specified as a one-sided P value <0.10. 39 participants with PAD (64.1% Black, 28.2% female) were randomized. Adjusting for age, race, smoking, and baseline performance, VM202 did not improve 6-minute walk at 6-month follow-up, compared to placebo (-13.5 meters, 90% confidence interval (CI): -38.5,+∞). At 3-month follow-up, VM202 improved maximum treadmill walking time (+2.38 minutes (90% CI: +1.08, +∞), P=0.014) and increased central nuclei abundance in gastrocnemius muscle (+5.86, 90% CI: +0.37,+∞, P=0.088), compared to placebo. VM202 did not significantly improve pain-free walking distance (difference: +0.30 minutes, 90% CI:-1.10,+∞, P=0.39), calf muscle perfusion (difference: +1.80 ml/minute per 100 g tissue, 90% CI: -3.80,+∞, P=0.33), or the WIQ distance score (difference: +2.02, 90% CI: -8.11,+∞, P=0.40). In post-hoc analyses, VM202 significantly improved 6-minute walk in PAD participants with diabetes mellitus at 6-month follow-up (+34.19 (90% CI: 4.04,+∞), P=0.075), but had no effect in people without diabetes (interaction P value=0.079). These data do not support gastrocnemius injections of VM202 to improve 6-minute walk in PAD. Secondary outcomes suggested potential benefit of VM202 on skeletal muscle measures and treadmill walking, while post-hoc analyses suggested benefit in PAD participants with diabetes.

The Use of Oxymetazoline 0.1% Ophthalmic Solution for Acquired Blepharoptosis: A Systematic Review.

Oxymetazoline hydrochloride has been shown to be effective in some studies for acquired blepharoptosis and for aesthetic upper eyelid elevation. This study aims to systematically review the literature on the use of topical oxymetazoline for treating acquired blepharoptosis. PubMed (U.S. National Library of Medicine, National Institutes of Health), Scopus (Elsevier), and Cochrane. A systematic review of studies published between 2013 and 2024 following PRISMA guidelines was performed using the PubMed, Scopus, and Cochrane databases. Primary outcomes included pre- to posttreatment change in marginal reflex distance (MRD1) after treatment with topical oxymetazoline, and mean difference (pre-to-posttreatment) in MRD1 versus control. Five articles included data from 458 patients for analysis. Meta-analysis demonstrated significant improvement in MRD1 measurements posttreatment with oxymetazoline (1.40 mm; 95% confidence interval, CI [0.41 mm, 2.40 mm]). In addition, when compared to controls, patients treated with oxymetazoline demonstrated greater increase in MRD1 values (0.83 mm; 95% CI [0.10 mm, 1.55 mmm]). Heterogeneity, measured by I2 statistic, was high in all studies (85%-95%). The use of oxymetazoline 0.1% ophthalmic solution significantly improves MRD1 in patients with acquired blepharoptosis. Further studies comparing this treatment in other etiologies of acquired blepharoptosis should be conducted. Laryngoscope, 135:8-14, 2025.

Associations between rural hospital closures and acute and post‐acute care access and outcomes

AbstractObjectiveTo determine whether rural hospital closures affected hospital and post‐acute care (PAC) use and outcomes.Study Setting and DesignUsing a staggered difference‐in‐differences design, we evaluated associations between 32 rural hospital closures and changes in county‐level: (1) travel distances to and lengths of stay at hospitals; (2) functional limitations at and time from hospital discharge to start of PAC episode; (3) 30‐day readmissions and mortality and hospitalizations for a fall‐related injury; and (4) population‐level hospitalization and death rates.Data Sources and Analytic Sample100% Medicare claims and home health and skilled nursing facility clinical data to identify approximately 3 million discharges for older fee‐for‐service Medicare beneficiaries.Principal FindingsWe found that hospitals that closed compared to those remaining open served more minoritized, lower‐income populations, including more Medicaid and fewer commercial patients, and had lower profit margins. Following a closure, quarterly hospitalization rates (111.6 quarterly hospitalizations per 10,000 older adults; 95% CI: 53.4, 170.9) and average hospital lengths of stay increased (0.34 days; 95% CI: 0.13, 0.56 days). We observed no change in the average distance between patients' residential ZIP code and the hospital used (0.29 miles; 95% CI: −1.06, 1.64 miles); average number of standardized ADL limitations at PAC (0.08 SDs from the pre‐closure average; 95% CI: −0.12, 0.28 SDs); or PAC time to start (0.02 days; 95% CI: −1.2, 1.2 days). Among more isolated hospitals, closures were associated with an increase in the likelihood of readmission (0.10 percentage‐points; 95% CI: 0.00, 0.19).ConclusionsClosures were not associated with notably worsened health care access, function, or health, potentially because closures triggered care delivery adjustments involving increased numbers of patients seeking out higher quality care.

Comparative breakthrough: Umbilical cord mesenchymal stem cells vs bone marrow mesenchymal stem cells in heart failure treatment.

In this article, we evaluate the comparative efficacy and safety of mesenchymal stem cells (MSCs) derived from bone marrow (BM-MSCs) and umbilical cord (UC-MSCs) in the treatment of heart failure and myocardial infarction. MSCs have gained importance as living bio drug due to their regenerative potential, with BM-MSCs being the most extensively studied. However, UC-MSCs offer unique advantages, such as noninvasive collection and fewer ethical concerns. This systematic review and meta-analysis summarizes data from 13 randomized controlled trials, which included a total of 693 patients. Their study shows that UC-MSCs significantly improved left ventricular ejection fraction by 5.08% at 6 months and 2.78% at 12 months compared with controls, while BM-MSCs showed no significant effect. Neither cell type showed significant changes in 6-minute walk distance. In addition, UC-MSCs and BM-MSCs had comparable safety profiles, with no significant differences in major adverse cardiac events, except for a lower rehospitalization rate observed with BM-MSCs. These results position UC-MSCs as a promising alternative in MSC-based therapies for cardiac disease, offering potential improvements in cardiac function while maintaining a favorable safety profile. Future research should focus on optimizing administration protocols and further exploring the long-term benefits and mechanisms of UC-MSCs in cardiac repair.

Design and Research on the Variable Polar Distance of the Double-Sided Linear Induction Motor for Electromagnetic Catapult

According to the special technical requirements of carrier-based aircraft catapults, this paper describes the design of a variable pole distance bilateral linear induction motor. When the traditional constant pole motor is used as the catapult of carrier-based aircraft, the current frequency continues to increase during the catapult process, which greatly aggravates the burden of the motor. Therefore, we propose a variable pole length primary double-sided linear induction motor structure. Compared with the traditional constant pole motor structure, this structure can gradually increase the pole distance with an increase in speed when the current frequency remains unchanged. In contrast, the variable pole distance method with a current frequency of 200 Hz has a pole distance of 0.262 m when the displacement is 10 m, and the pole distance increases to 0.352 m when the displacement is 100 m. By maintaining a constant current frequency, this method effectively reduces the control complexity at high speed. Through the theoretical analysis and research calculation conducted on the designed motor, a finite element simulation model was also established by ANSYS 14.0, and the influence of the change in the pole distance on the performance of the motor was analyzed. The magnetic field line and magnetic density distribution of the motor are simulated and analyzed, and the validity of the theoretical calculation is verified.

Impact of Self-Contained Breathing Apparatus on Air Gaps in Structural Firefighting Personal Protective Clothing

The self-contained breathing apparatus (SCBA) is an integral part of the structural firefighting personal protective equipment (PPE) ensemble. However, when donned, it adds significant weight and restriction, interfering with the fit of the turnout suit and the ventilation within the clothing system. This may result in a reduction of air gaps within the clothing microclimate, quickening the onset of heat strain. Therefore, the purpose of this study was to assess the impact of the SCBA on air gaps in structural firefighting turnout suits. Nine active-duty male firefighter participants were scanned in a three-dimensional body scanner in four garment configurations (compression, base layers, turnout suit, and turnout with SCBA). Torso volume, surface area, and air gaps were calculated alongside ease measurements. Findings demonstrated a 59% increase in torso volume when donning the turnout suit over base layers compared to a 1.2% reduction in torso volume when donning the SCBA. The change in torso air gap volume and distance were also found to be negligible when donning the SCBA. This study lays the foundation for full systems ensemble research needed to better understand how the design, weight, and fit of the SCBA impacts the thermal comfort, mobility, and protection of structural firefighters.