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Optics Express Sep 2022Brillouin fiber sensors have demonstrated strong capability in discriminative and high-sensitivity multiparameter measurements. In this study, we proposed and...
Brillouin fiber sensors have demonstrated strong capability in discriminative and high-sensitivity multiparameter measurements. In this study, we proposed and numerically investigated novel ring core fiber-based stimulated Brillouin scattering for the simultaneous measurement of temperature and strain. The novel fiber, referred to as ring hyperbolic tangent (R-HTAN) fiber, is characterized by a shape parameter (α) that controls the optical refractive index and longitudinal acoustic velocity profiles. Numerical modal simulations indicated that the Brillouin gain spectrum contained multiple widely spaced and high-gain peaks, which were attributed to the strong interaction between the optical linearly polarized mode (i.e., LP as a pump wave) and multiple high-order longitudinal acoustic modes. The designed R-HTAN fiber enabled the discriminative sensing of temperature and strain with levels that clearly surpassed values recently reported in the literature. In case of straight R-HTAN fiber (α = 0), the maximum (=0) and (=0) are 1.928 MHz/ C and 0.087 MHz, respectively. In case of graded R-HTAN fiber (α = 1), the maximum (=1) and (=1) are 1.872 MHz/ C and 0.0842 MHz/μɛ, respectively. The errors associated with temperature measurements (maximum δT = 0.0846 C and maximum δT = 7.4184 C) and strain measurements (maximum δɛ = 0.7250 μɛ and maximum δɛ = 7.4184 μɛ) demonstrated that the proposed fiber could be a promising candidate for next-generation Brillouin sensing systems for enabling temperature and strain discrimination.
PubMed: 36242470
DOI: 10.1364/OE.471647 -
International Journal of Surgery... Aug 2023Monitoring of abdominal aortic aneurysms (AAAs) is currently based on serial measurements of maximum aortic diameter. Additional assessment of aneurysm volume has...
BACKGROUND
Monitoring of abdominal aortic aneurysms (AAAs) is currently based on serial measurements of maximum aortic diameter. Additional assessment of aneurysm volume has previously been proposed to possibly improve growth prediction and treatment decisions. To evaluate the use of supplementing volume measurements, the authors aimed to characterise the growth distribution of AAA volume and to compare the growth rates of the maximum diameter and volume at the patient level.
METHODS
Maximum diameter and volume were monitored every 6 months in 84 patients with small AAAs, with a total of 331 computed tomographic angiographies (with initial maximum diameters of 30-68 mm). A previously developed statistical growth model for AAAs was applied to assess the growth distribution of volume and to compare individual growth rates for volume and for maximum diameter.
RESULTS
The median (25-75% quantile) expansion in volume was 13.4 (6.5-24.7) % per year. Cube root transformed volume and maximum diameter showed a closely linear association with a within-subject correlation of 0.77. At the surgery threshold maximum diameter of 55 mm, the median (25-75% quantile) volume was 132 (103-167) ml. In 39% of subjects, growth rates for volume and maximum diameter were equivalent, in 33% growth was faster in volume and in 27% growth was faster in maximum diameter.
CONCLUSION
At the population level, volume and maximum diameter show a substantial association such that the average volume is approximately proportional to the average maximum diameter raised to a power of three. At the individual level, however, in the majority of patient's AAAs grow at different pace in different dimensions. Hence, closer monitoring of aneurysms with sub-critical diameter but suspicious morphology may benefit from complementing maximum diameter by volume or related measurements.
Topics: Humans; Cohort Studies; Aortic Aneurysm, Abdominal; Risk Factors
PubMed: 37402309
DOI: 10.1097/JS9.0000000000000433 -
BMC Bioinformatics Nov 2019Maximum parsimony reconciliation in the duplication-transfer-loss model is a widely-used method for analyzing the evolutionary histories of pairs of entities such as...
BACKGROUND
Maximum parsimony reconciliation in the duplication-transfer-loss model is a widely-used method for analyzing the evolutionary histories of pairs of entities such as hosts and parasites, symbiont species, and species and genes. While efficient algorithms are known for finding maximum parsimony reconciliations, the number of such reconciliations can be exponential in the size of the trees. Since these reconciliations can differ substantially from one another, making inferences from any one reconciliation may lead to conclusions that are not supported, or may even be contradicted, by other maximum parsimony reconciliations. Therefore, there is a need to find small sets of best representative reconciliations when the space of solutions is large and diverse.
RESULTS
We provide a general framework for hierarchical clustering the space of maximum parsimony reconciliations. We demonstrate this framework for two specific linkage criteria, one that seeks to maximize the average support of the events found in the reconciliations in each cluster and the other that seeks to minimize the distance between reconciliations in each cluster. We analyze the asymptotic worst-case running times and provide experimental results that demonstrate the viability and utility of this approach.
CONCLUSIONS
The hierarchical clustering algorithm method proposed here provides a new approach to find a set of representative reconciliations in the potentially vast and diverse space of maximum parsimony reconciliations.
Topics: Algorithms; Classification; Cluster Analysis; Computational Biology; Evolution, Molecular; Models, Genetic; Phylogeny
PubMed: 31775628
DOI: 10.1186/s12859-019-3223-5 -
Progress in Pediatric Cardiology Mar 2021In the setting of the coronavirus disease 2019 (COVID-19) pandemic, an emergency hospital-wide eWork policy was enacted at Boston Children's Hospital on March 16, 2020.... (Review)
Review
In the setting of the coronavirus disease 2019 (COVID-19) pandemic, an emergency hospital-wide eWork policy was enacted at Boston Children's Hospital on March 16, 2020. The number of clinicians on campus was restricted to only essential personnel, guidelines limited clinical care delivery to solely non-elective patients, and strict maximums were placed on the numbers of people allowed to congregate in the same physical space. With this abrupt transition to social distancing and electronic communication, the established approach to educating graduate medical trainees became obsolete overnight. Anticipating significant impact on trainee and faculty professional and personal lives, the importance of adaptive teaching strategies was evident. This document details one approach to redesigning the clinical learning system including a description of the learners and environment, the pedagogical principles that guided the approach, and technological tools used in implementation. Additionally, available literature pertinent to this topic is explored, assessment of the work to date is presented, and suggestions are provided regarding future directions related to online graduate medical education.
PubMed: 33169056
DOI: 10.1016/j.ppedcard.2020.101320 -
JAMA Network Open Nov 2021One-third of US residents have trouble paying their medical bills. They often turn to their physicians for help navigating health costs and insurance coverage.
IMPORTANCE
One-third of US residents have trouble paying their medical bills. They often turn to their physicians for help navigating health costs and insurance coverage.
OBJECTIVE
To determine whether physicians can accurately estimate out-of-pocket expenses when they are given all of the necessary information about a drug's price and a patient's insurance plan.
DESIGN, SETTING, AND PARTICIPANTS
This national mail-in survey used a random sample of US physicians. The survey was sent to 900 outpatient physicians (300 each of primary care, gastroenterology, and rheumatology). Physicians were excluded if they were in training, worked primarily for the Veterans Administration or Indian Health Service, were retired, or reported 0% outpatient clinical effort. Analyses were performed from July to December 2020.
MAIN OUTCOMES AND MEASURES
In a hypothetical vignette, a patient was prescribed a new drug costing $1000/month without insurance. A summary of her private insurance information was provided, including the plan's deductible, coinsurance rates, copays, and out-of-pocket maximum. Physicians were asked to estimate the drug's out-of-pocket cost at 4 time points between January and December, using the plan's 4 types of cost-sharing: (1) deductibles, (2) coinsurance, (3) copays, and (4) out-of-pocket maximums. Multivariate linear regression was used to assess differences in performance by specialty, adjusting for attitudes toward cost conversations, demographics, and clinical characteristics.
RESULTS
The response rate was 45% (405 of 900) and 371 respondents met inclusion criteria. Among the respondents included in this study, 59% (n = 220) identified as male, 23% (n = 84) as Asian, 3% (n = 12) as Black, 6% (n = 24) as Hispanic, and 58% (n = 216) as White; 30% (n = 112) were primary care physicians, 35% (n = 128) were gastroenterologists, and 35% (n = 131) were rheumatologists; and the mean (SD) age was 49 (10) years. Overall, 52% of physicians (n = 192) accurately estimated costs before the deductible was met, 62% (n = 228) accurately used coinsurance information, 61% (n = 224) accurately used copay information, and 57% (n = 210) accurately estimated costs once the out-of-pocket maximum was met. Only 21% (n = 78) of physicians answered all 4 questions correctly. Ability to estimate out-of-pocket costs was not associated with specialty, attitudes toward cost conversations, or clinic characteristics.
CONCLUSIONS AND RELEVANCE
This survey study found that many US physicians have difficulty estimating out-of-pocket costs, even when they have access to their patients' insurance plans. The mechanics involved in calculating real-time out-of-pocket costs are complex. These findings suggest that increased price transparency and simpler insurance cost-sharing mechanisms are needed to enable informed cost conversations at the point of prescribing.
Topics: Attitude of Health Personnel; Cost Sharing; Deductibles and Coinsurance; Fees and Charges; Female; Health Expenditures; Humans; Insurance Coverage; Male; Patient Care Team
PubMed: 34739059
DOI: 10.1001/jamanetworkopen.2021.33188 -
Thoracic Research and Practice Jan 2023This study aimed to determine the maximum diameters of the pulmonary artery and ascending aorta and their ratio to each other to enable early diagnosis and treatment of...
OBJECTIVE
This study aimed to determine the maximum diameters of the pulmonary artery and ascending aorta and their ratio to each other to enable early diagnosis and treatment of possible pulmonary hypertension and to prevent possible complications in patients infected with severe acute respiratory syndrome coronavirus 2.
MATERIAL AND METHODS
A total of 120 patients aged 40 years and older, 60 patients (30 females and 30 males) with severe acute respiratory syndrome coronavirus 2 infection and 60 individuals (30 females and 30 males), were included in this retrospective study. Maximum pulmonary artery and maximum ascending aorta diameters were measured at the level of bifurcatio trunci pulmonalis in the transverse axial plane by computed tomography, and their ratios to each other were determined.
RESULTS
Our study revealed a statistically significant increase in maximum pulmonary artery and maximum ascending aorta diameters in both genders in patients with coronavirus disease 2019 compared to the control group and a statistically significant increase was found in the maximum pulmonary artery-maximum ascending aorta ratio in women with coronavirus disease 2019 compared to the control group (P < .05).
CONCLUSIONS
Knowing the diameters of maximum pulmonary artery and maximum ascending aorta and the maximum pulmonary artery-maximum ascending aorta ratio in hospitalized severe acute respiratory syndrome coronavirus 2-infected patients is a valuable predictive marker of pulmonary hypertension and a guide in determining the appropriate treatment. These data, which are easy to calculate from thorax computed tomography, may be beneficial in the prognosis of the disease.
PubMed: 37503598
DOI: 10.5152/ThoracResPract.2023.22107 -
Journal of Healthcare Engineering 2022To explore the correlation between the maximum percentage heart rate and the maximum percentage oxygen intake, provide an evaluation basis for heart rate for the...
To explore the correlation between the maximum percentage heart rate and the maximum percentage oxygen intake, provide an evaluation basis for heart rate for the assessment of exercise load intensity. Four boys and 4 girls were randomly selected, aged 26.25 ± 2.12 years old with good health, good cardiopulmonary function, no other medical history, and irregular physical training history. The subject measured the first 30 min of rest at 25°C at room temperature, kept awake and static, and the heart rate was measured as the quiet heart rate in the state. Prepredicted maximum heart rate and health index were determined according to the Polar s810 heart rate table instructions. Prepredicted maximum heart rate and health index were measured three consecutive times and reliability analysis was performed on three measurements. The regression equations were established by a stepwise method with data represented that all metrics were tested for normality for fitness index and maximum oxygen intake compared using a paired test with a significance level of < 0.05. The results showed that the highest value of VO motor cardiopulmonary test was 47.83 ml/(kg·min), the lowest was 35.06 ml/(kg·min), the two-step test was 44.50 ml/(kg·min), and the lowest was 32.89 ml/(kg min).With a positive correlation between the postexercise heart rate and the maximum oxygen intake, the maximum oxygen intake value can be indirectly inferred using the heart rate after the exercise and the work completed by the exercise. The results measured by two-step test have some accuracy and can be used to speculate the maximum oxygen intake in the ordinary young population. The polar heart rate meter allows subjects to indirectly measure the maximum oxygen intake in silence, requiring less equipment and being easy to operate. The indirect measurement of the maximum oxygen intake can be used for the monitoring of competitive sports and national fitness.
Topics: Adult; Exercise; Exercise Test; Female; Heart Rate; Humans; Male; Oxygen; Oxygen Consumption; Reproducibility of Results; Respiration; Young Adult
PubMed: 35295176
DOI: 10.1155/2022/6281199 -
Frontiers in Sports and Active Living 2022Sprinting performance is critical for a variety of sports and competitive activities. Prior research has demonstrated correlations between the limits of initial...
Sprinting performance is critical for a variety of sports and competitive activities. Prior research has demonstrated correlations between the limits of initial acceleration and maximum velocity for athletes of different sprinting abilities. Our perspective is that hip torque is a mechanistic link between these performance limits. A theoretical framework is presented here that provides estimates of sprint acceleration capability based on thigh angular acceleration and hip torque during the swing phase while running at maximum velocity. Performance limits were calculated using basic anthropometric values (body mass and leg length) and maximum velocity kinematic values (contact time, thigh range of motion, and stride frequency) from previously published sprint data. The proposed framework provides a mechanistic link between maximum acceleration and maximum velocity, and also explains why time constant values (τ, ratio of the velocity limit to acceleration limit) for sprint performance curves are generally close to one-second even for athletes with vastly different sprinting abilities. This perspective suggests that specific training protocols targeted to improve thigh angular acceleration and hip torque capability will benefit both acceleration and maximum velocity phases of a sprint.
PubMed: 35903404
DOI: 10.3389/fspor.2022.945688 -
Annals of Translational Medicine Sep 2022Tibial plateau fractures (TPFs) are a challenging type of fracture in orthopedic traumatology. We previously designed a plate (Patent Number: CN201520195596.5) for...
BACKGROUND
Tibial plateau fractures (TPFs) are a challenging type of fracture in orthopedic traumatology. We previously designed a plate (Patent Number: CN201520195596.5) for posterolateral TPF combined with posterior lateral collapse.. In this study, finite element analysis was used to compare the biomechanical characteristics of two internal fixation methods for posterolateral TPF. We investigated the support effect of the new steel plate on lateral TPFs combined with posterior TPFs.
METHODS
Two models of complex TPF were established. Model A was fixed with the new type of plate, and model B was fixed without the plate. Three axial loads of 500, 1,000, and 1,500 N were applied using FEA on the two fracture models (A and B) to analyze the data.
RESULTS
In model A, the maximum displacement at 500, 1,000, and 1,500 N was 0.085797, 0.17043, and 0.25465 mm, respectively; the maximum stress of the bone block was 11.285, 20.648, and 29.227 MPa, respectively; and the maximum strain of the bone block was 0.0012474, 0.007435, and 0.0035769 mm, respectively. The maximum displacement of the internal fixation was 0.096932, 0.18682, and 0.27655 mm, respectively; the maximum stress was 69.54, 112.1, and 155.71 MPa, respectively; and the maximum strain was 0.00066228, 0.0010676, and 0.0014829 mm, respectively. In model B, the maximum displacement of fractures at 500, 1,000, and 1,500 N was 0.15675, 0.29868, and 0.44017 mm, respectively; the maximum stress of the bone block was 6.5519, 12.575, and 18.842 MPa, respectively; and the maximum strain of the bone block was 0.0032554, 0.0074357, and 0.012146 mm, respectively. The maximum displacement of the screw was 0.14177, 0.27109, and 0.39849 mm, respectively; the maximum stress was 48.916, 92.251, and 135.27 MPa, respectively; and the maximum strain was 0.00046608, 0.00087893, and 0.0012887 mm, respectively.
CONCLUSIONS
The fixation method using this type of plates and screws can replace other methods using two plates to fix complex TPF.
PubMed: 36267738
DOI: 10.21037/atm-22-4529 -
Sports (Basel, Switzerland) Feb 2021Barefoot weightlifting has become a popular training modality in recent years due to anecdotal suggestions of improved performance. However, research to support these...
Barefoot weightlifting has become a popular training modality in recent years due to anecdotal suggestions of improved performance. However, research to support these anecdotal claims is limited. Therefore, the purpose of this study was to assess the differences between the conventional deadlift (CD) and the sumo deadlift (SD) in barefoot and shod conditions. On day one, one-repetition maximums (1 RM) were assessed for thirty subjects in both the CD and SD styles. At least 72 h later, subjects returned to perform five repetitions in four different conditions (barefoot and shod for both CD and SD) at 70% 1 RM. A 2 × 2 (footwear × lifting style) MANOVA was used to assess differences between peak vertical ground reaction force (VGRF), total mechanical work (WORK), barbell vertical displacement (DISP), peak vertical velocity (PV) and lift time (TIME) during the concentric phase. The CD displayed significant increases in VGRF, DISP, WORK, and TIME over the SD. The shod condition displayed increased WORK, DISP, and TIME compared to the barefoot condition. This study suggests that lifting barefoot does not improve performance as no differences in VGRF or PV were evident. The presence of a shoe does appear to increase the DISP and WORK required to complete the lift, suggesting an increased work load is present while wearing shoes.
PubMed: 33670253
DOI: 10.3390/sports9020027