Average Delta Research Articles

Handgrip Evaluation Before and After Pulmonary Rehabilitation Therapy in Patients With Chronic Obstructive Pulmonary Disease (COPD).

Introduction Chronic Obstructive Pulmonary Disease (COPD) is a systemic disease characterized by skeletal muscle dysfunction, leading to increased morbidity and mortality and deteriorating quality of life. Pulmonary rehabilitation therapy improves symptoms and long-term adherence. This study aimed to evaluate how COPD patients respond to pulmonary rehabilitation therapy and its correlation with handgrip strength measurements. Materials and methods A prospective cohort study was conducted in patients over 45 years old with a spirometric diagnosis of COPD from a specialized reference center in Bucaramanga. Handgrip strength was measured before and after completing the pulmonary rehabilitation program. Patients with neurological or cognitive impairments, decompensated cardiovascular disease, nutritional diseases, or those in a telerehabilitation program were excluded. Results Seventy-one patients were included in the study, with 66.2% completing follow-up after the program. The average age was 73.38 years (SD ±7.77), 53.52% were women, and 60.56% had a history of smoking. After the follow-up, the average handgrip strength delta was 1.64 kg (SD ±3.48) p<0.001, 74.47% of them representing a positive result after pulmonary rehabilitation program. A higher Charlson index correlated with a positive delta, while a negative delta correlated with a lower Charlson index (p=0.01). A positive handgrip strength delta was associated with higher baseline quality of life scores. Conclusions Periodic handgrip strength measurements predict frailty and muscle dysfunction in COPD patients. Pulmonary rehabilitation therapy isa simple and cost-effective intervention that correlates with the improvement of indirect prognosis and survival indicators.

Evaluation of the Xpert Carba-R assay for quantifying carbapenemase-producing bacterial load in stool samples.

The spread of Carbapenemase-producing Organisms (CPO) remains a major threat globally. Within clinical settings, the existing method of determining gene load involves traditional culture to determine bacterial load and polymerase-chain-reaction-based Xpert Carba-R Assay to determine carbapenemase gene type. However, there is a need for a fast and accurate method of quantifying CPO colonisation to study the risk of persistent CPO carriage. This study evaluated the accuracy of Xpert Carba-R Ct value in estimating carbapenamase producing bacterial loads in stool samples. Stool samples were obtained from an ongoing study investigating the household transmission of CPO in Singapore. Stool samples lacking carbapenemase producing organisms were spiked with organism carrying a single carbapenemase gene (blaKPC, blaNDM, blaVIM, blaOXA-48(-like) or blaIMP-1) and serially diluted before being subjected to Xpert Carba-R assay and traditional culture. Standard curves with regression lines showing correlation between Ct values and plate counts were generated. The standard curves were validated with stool samples collected from patients. The limit of detection of blaNDM, blaKPC, and blaOXA-48 was approximately 103 cfu/mL, while that of blaIMP-1 and blaVIM was approximately 104 cfu/mL. Validation of the blaNDM and blaOXA-48 curves revealed average delta values of 0.56 log(cfu/mL) (95% CI 0.24-0.88) and 0.80 log(cfu/mL) (95% CI 0.53-1.07), respectively. Our validation data for stool positive for blaNDM and blaOXA-48-type suggests that bacterial loads can be estimated within a reasonable range of error.

Short-Term Changes in Hypsarrhythmia Assessed by Spectral Analysis: Group and Individual Assessments.

Objectives: To perform spectral analysis on previously recorded electroencephalograms (EEGs) containing hypsarrhythmia in an initial recording and to assess changes in spectral power (µV2) in a follow-up recording after a period of 10-25 days. Methods: Fifty participants, aged 2-39 months, with hypsarrhythmia in an initial recording (R1), were compared with regard to their spectral findings in a later recording (R2). Typically, anticonvulsant therapy was initiated or modified after R1. Average delta, theta, alpha, and beta power was derived from approximately 3 min of artifact-free EEG data recorded from 19 electrode derivations. Group and individual changes in delta power between R1 and R2 formed the main analyses. Results: Delta accounted for 84% of the total power. In group comparisons, median delta power decreased statistically significantly between R1 and R2 in all 19 derivations, for example, from 3940 µV2 in R1 to 1722 µV2 in R2, Cz derivation. When assessing individual participants, delta power decreases in R2 were >50% in 60% of the participants, but <25% in 24% of the participants. Conclusion: Spectral analysis may be used as an additional tool for providing a potential biomarker in the assessment of short-term changes in hypsarrhythmia, including the effects of treatment.

Counting your chickens before they hatch: improvements in an untreated chronic pain population, beyond regression to the mean and the placebo effect.

Isolating the effect of an intervention from the natural course and fluctuations of a condition is a challenge in any clinical trial, particularly in the field of pain. Regression to the mean (RTM) may explain some of these observed fluctuations. In this paper, we describe and quantify the natural trajectory of questionnaire scores over time, based on initial scores. Twenty-seven untreated chronic low back pain patients and 25 healthy controls took part in this observational study, wherein they were asked to complete an array of questionnaires commonly used in pain studies during each of 3 visits (V1, V2, V3) at the 2-month interval. Scores at V1 were classified into 3 subgroups (extremely high, normal, and extremely low), based on z-scores. The average delta (∆ = V2 - V1) was calculated for each subgroup, for each questionnaire, to describe the evolution of scores over time based on initial scores. This analysis was repeated with the data for V2 and V3. Our results show that high initial scores were widely followed by more average scores, while low initial scores tended to be followed by similar (low) scores. These trajectories cannot be attributable to RTM alone because of their asymmetry, nor to the placebo effect as they occurred in the absence of any intervention. However, they could be the result of an Effect of Care, wherein participants had meaningful improvements simply from taking part in a study. The improvement observed in patients with high initial scores should be carefully taken into account when interpreting results from clinical trials.

Use of Machine Learning for Early Detection of Maternal Cardiovascular Conditions: Retrospective Study Using Electronic Health Record Data.

Cardiovascular conditions (eg, cardiac and coronary conditions, hypertensive disorders of pregnancy, and cardiomyopathies) were the leading cause of maternal mortality between 2017 and 2019. The United States has the highest maternal mortality rate of any high-income nation, disproportionately impacting those who identify as non-Hispanic Black or Hispanic. Novel clinical approaches to the detection and diagnosis of cardiovascular conditions are therefore imperative. Emerging research is demonstrating that machine learning (ML) is a promising tool for detecting patients at increased risk for hypertensive disorders during pregnancy. However, additional studies are required to determine how integrating ML and big data, such as electronic health records (EHRs), can improve the identification of obstetric patients at higher risk of cardiovascular conditions. This study aimed to evaluate the capability and timing of a proprietary ML algorithm, Healthy Outcomes for all Pregnancy Experiences-Cardiovascular-Risk Assessment Technology (HOPE-CAT), to detect maternal-related cardiovascular conditions and outcomes. Retrospective data from the EHRs of a large health care system were investigated by HOPE-CAT in a virtual server environment. Deidentification of EHR data and standardization enabled HOPE-CAT to analyze data without pre-existing biases. The ML algorithm assessed risk factors selected by clinical experts in cardio-obstetrics, and the algorithm was iteratively trained using relevant literature and current standards of risk identification. After refinement of the algorithm's learned risk factors, risk profiles were generated for every patient including a designation of standard versus high risk. The profiles were individually paired with clinical outcomes pertaining to cardiovascular pregnancy conditions and complications, wherein a delta was calculated between the date of the risk profile and the actual diagnosis or intervention in the EHR. In total, 604 pregnancies resulting in birth had records or diagnoses that could be compared against the risk profile; the majority of patients identified as Black (n=482, 79.8%) and aged between 21 and 34 years (n=509, 84.4%). Preeclampsia (n=547, 90.6%) was the most common condition, followed by thromboembolism (n=16, 2.7%) and acute kidney disease or failure (n=13, 2.2%). The average delta was 56.8 (SD 69.7) days between the identification of risk factors by HOPE-CAT and the first date of diagnosis or intervention of a related condition reported in the EHR. HOPE-CAT showed the strongest performance in early risk detection of myocardial infarction at a delta of 65.7 (SD 81.4) days. This study provides additional evidence to support ML in obstetrical patients to enhance the early detection of cardiovascular conditions during pregnancy. ML can synthesize multiday patient presentations to enhance provider decision-making and potentially reduce maternal health disparities.

A rapid colorimetric sensing methodology for urinary tract bacterial pathogens as a point-of-care approach using natural anthocyanin loaded nanosilver

Various commercial diagnostic kits have been used to detect uropathogens. However, non-intensive, sensitive, and instantaneous detection of bacteria in urine is still at its infancy. Herein, a facile attempt was carried out to detect the most common uropathogens using anthocyanin-loaded silver nanoparticles as the indicator. The significance of the current research was to apply the crucial sensing ability of eggplant peel anthocyanin to detect each pathogen by exhibiting discrete colors, based on pH of the urine sample. The novelty of this study was the ability of a single indicator compound to distinctively differentiate multiple uropathogens, as monocultures or consortia, with accurate chromacity, simultaneously and instantaneously. Anthocyanin (AC) from eggplant (Solanum melongena) peels acted as a pH responsive sensor in the prepared indicator solution. The solution was used to sense three each of Gram-positive and Gram-negative uropathogens, as both monoculture and consortium. AC was loaded onto silver nanoparticles (AgNP) to stabilize the pigment. An evident color change due to the function of AC was considered as the end-point of detection. The optimized conditions for the study were obtained as: 50 μL indicator solution, 105CFU.mL−1 inoculum, and instantaneous sensing time. Deprotonation and protonation of AC due to ammonia and acids, evolved from the microbes, subsequently varied the pH level in the medium. These resulted in the generation of colors as hues of yellow, orange, green and blue and semi-quantitatively represented using average RGB values and delta E analysis obtained after the indicator solution was added to 24 h bacterial growth. In conclusion, the proposed solution can be a potential alternative to the conventional diagnostic tools as a specific, sensitive, rapid, precise and affordable indicator for point-of-care diagnosis of urinary tract infection.

Convex Hull Prediction for Adaptive Video Streaming by Recurrent Learning.

Adaptive video streaming relies on the construction of efficient bitrate ladders to deliver the best possible visual quality to viewers under bandwidth constraints. The traditional method of content dependent bitrate ladder selection requires a video shot to be pre-encoded with multiple encoding parameters to find the optimal operating points given by the convex hull of the resulting rate-quality curves. However, this pre-encoding step is equivalent to an exhaustive search process over the space of possible encoding parameters, which causes significant overhead in terms of both computation and time expenditure. To reduce this overhead, we propose a deep learning based method of content aware convex hull prediction. We employ a recurrent convolutional network (RCN) to implicitly analyze the spatiotemporal complexity of video shots in order to predict their convex hulls. A two-step transfer learning scheme is adopted to train our proposed RCN-Hull model, which ensures sufficient content diversity to analyze scene complexity, while also making it possible to capture the scene statistics of pristine source videos. Our experimental results reveal that our proposed model yields better approximations of the optimal convex hulls, and offers competitive time savings as compared to existing approaches. On average, the pre-encoding time was reduced by 53.8% by our method, while the average Bjøntegaard delta bitrate (BD-rate) of the predicted convex hulls against ground truth was 0.26%, and the mean absolute deviation of the BD-rate distribution was 0.57%.

Cross-Component Prediction Boosted With Local and Non-Local Information in Video Coding.

In the versatile video coding (VVC) standard, cross-component prediction (CCP) is introduced to utilize the correlation between luma and chroma components. To further exploit the cross-component redundancy, a bundle of novel CCP methods with more sophisticated models are studied in enhanced compression model (ECM), which is a platform targeting at the next generation video coding standard, developed by JVET. This paper presents two methods, known as local-boosting CCP (LB-CCP) and non-local CCP (NL-CCP) to improve CCP with local and non-local information. With LB-CCP, prediction samples of CCP can be filtered with neighbouring samples. Besides, neighbouring template costs are calculated to determine the range of training samples, as well as the cross-component prediction method used in the chroma fusion mode. With NL-CCP, a CCP model can be derived with samples non-adjacent to the current block. As an equivalent but simpler implementation, the CCP model can be inherited from a CCP-coded neighbouring block as a spatial CCP candidate. Moreover, the CCP model of a previous CCP-coded block can be stored in a history-based table, which can be fetched and used by the current block as a history-based CCP candidate. A NL-CCP candidate list is built with the two kinds of candidates. The encoder can select the optimal candidate and send an index to the decoder. Experimental results show that LB-CCP together with NL-CCP can provide an average Bjontegaard delta rate (BD-rate) reduction of 0.27%, 2.31%, 2.44% on Y, Cb, Cr components, respectively, with a negligible change in the running time, compared with ECM-8.0 in all intra configurations. Both LB-CCP and NL-CCP have been adopted into ECM.

Reference standards for stress radiography measurements in knee ligament injury and instability: a systematic review

AbstractPurposeStress radiographs are an easily accessible, cost‐effective tool in the evaluation of acute and chronic ligament knee injuries. Stress radiographs provide an objective, quantifiable, and functional assessment of the injured ligament and can be a useful adjunct when planning surgical management and to objectively assess postoperative outcomes. This study aimed to review the literature reporting on stress radiographic techniques in evaluating knee ligament injury and instability and propose thresholds for interpreting stress radiography techniques.MethodsThe following three databases, OVID MEDLINE, the EMBASE library, and the Cochrane Controlled Trials Register, were systematically searched on January 23, 2023, for studies published from January 1970 to January 2023. The search extended to the reference lists of all relevant studies and orthopedic journals. Included studies were those that described a stress technique for the diagnosis of knee ligament injury; studies that reported a description or comparison of the accuracy and/or reliability of one or several stress radiography techniques, or studies that reported a comparison with alternative diagnostic modalities.ResultsSixteen stress radiography techniques were reported for assessing the ACL with stress applied in the anterior plane, 10 techniques for assessing the PCL with stress applied in the posterior plane, 3 techniques for valgus stress, and 4 techniques for varus stress. The Telos device was the most commonly used stress device in the ACL and PCL studies. There was no consensus on the accuracy and reliability of stress radiography techniques for the diagnosis of any knee ligament injury. Stress radiography techniques were compared with alternative diagnostic techniques including instrumented arthrometry, MRI, and physical examination in 18 studies, with variability in the advantages and disadvantages of stress radiography techniques and alternatives. Analysis of results pooled from different studies demonstrated average delta gapping in knees with a completely injured ligament compared to the normal contralateral knee as per the following: for the ACL 4.9 ± 1.4 mm; PCL 8.1 ± 2.5 mm; MCL 2.3 ± 0.05 mm; and the FCL 3.4 ± 0.2 mm.ConclusionDespite heterogeneity in the available literature with regard to stress examination techniques and device utilization, the data support that stress radiography techniques were accurate and reliable when compared to numerous alternatives in the diagnosis of acute and chronic knee ligament injuries. The present study also provides average increased ipsilateral compartment gapping/translation for specific knee ligament injuries based on the best available data. These values provide a reference standard for the interpretation of stress radiography techniques, help to guide surgical decision‐making, and provide benchmark values for future investigations.Level of evidenceIII.

Expression of human cardiac-specific genes: a novel method for post-mortem interval estimation.

In legal medicine, the determination of post-mortem interval (PMI) is not only an important but also one of the most difficult aspects. Several methods are used to estimate PMI such as physicochemical, entomological, biochemical, metabolic, autolytic, and physical methods. These methods provide a wide range of PMI as they are affected by different factors. The approach behind the present study is to calculate an accurate PMI by using mRNA degradation and fold change expression (FCE) of cardiac-specific genes viz. N-terminal pro-B-type natriuretic peptide (NPPB) and cardiac troponin I (TNNI3). Seventeen cadaver heart tissues were analysed within a time frame of up to 12 hours from the time since death, at different time intervals at room temperature. Gene expression was determined and the data were analysed using the value of average delta Ct (ΔCt) value of the assessed gene and housekeeping gene. Delta delta Ct (ΔΔCt) method was used to calculate the FCE at the different 7-time groups. The FCE of TNNI3 was almost stable till 15 hours of PMI and then after 15 hours, expression shows a decrease up to 24 hours after death; whereas, NPPB shows that FCE was stable till 12 hours of PMI and then after 12 hours, expression shows a decrease up to 24 hours after death. The FCE of NPPB and TNNI3 was almost stable till 12 hours. Thus, the estimation of PMI by analysis of the FCE of cardiac-specific genes can be a new promising method in forensic medicine.

An efficient hybrid algorithm for non-contact physiological sign monitoring using plethysmography wave analysis

ABSTRACT Nowadays, a variety of studies have shown that a person’s physiological indicators can be reliably extracted from a distance through an RGB camera. For this purpose, our work suggests an effective hybrid approach based on photoplethysmographic signal (PPG) analysis for the continuous monitoring of physiological signs, including heart rate and respiration rate. Our approach presents dependable methods for image and signal processing that combine moving average filtering and successive variable mode decomposition methods (w.r.t. MAF-SVMD). These two latter approaches will be applied to the PPG signal in order to overcome drawbacks, filter the disturbances in the signal, and decompose the PPG signal. Additionally, the suggested method, MAF-SVMD, has much lower computational complexity and is more robust to the initial values. Our findings were contrasted with those of traditional techniques, including EMD and VMD methods. Between the proposed approach and the VMD algorithm, the derived respiratory rates show an average delta error of 0 and a coefficient correlation of 0.99; however, between the suggested technique and the EMD method, the relative delta value is equal to 7.71 and a coefficient correlation of 0.69. While the retrieved heart rate from each of the three methods shown is generally convergent to the same value.

O-077 Time-lapse imaging analysis of segmental aneuploid embryos: a multicenter study identifies morpho-kinetic patterns associated with chromosomal mosaicism

Abstract Study question Do segmental aneuploid (SA) embryos display unique morpho-kinetic patterns at early developmental stages? Summary answer The first three cell division cycles of embryos carrying segmental aneuploidies are significantly slower than euploid and whole-chromosome aneuploid (WCA) embryos. What is known already Segmental aneuploidies in blastocyst-stage human embryos prevalently originate (i.e., 70% of cases) from mitotic errors. Their clinical management is challenging because it is impossible to establish their meiotic/mitotic origin from PGT-A analysis of a single trophectoderm biopsy. Morpho-kinetic analysis based on Time-lapse microscopy (TLM) has been proposed as a valuable tool for systematic embryo evaluation, although it is unclear whether this approach alone can predict chromosomal abnormalities. This study aims to pinpoint morphokinetic patterns associated with the occurrence of segmental aneuploidies and/or mitotic errors, possibly improving DNA-based diagnostic interpretation and their clinical management. Study design, size, duration This is a retrospective multicenter study including a total of 7,693 embryos from 2,370 IVF cycles and 2,127 couples, cultured between 2016 and 2021 in 4 European IVF centers. Embryos with no more than 4 chromosomal alterations were considered in the analysis, resulting in 3,288 euploids, 3,155 WCA, 715 SA, and 535 complex aneuploids (CA). Overall, the dataset contained 3,742 distinct euploid-SA embryo sibling pairs. Participants/materials, setting, methods Standard morpho-kinetic features were annotated using various TLM systems. Blastocysts were subjected to comprehensive chromosomal screening via PGT-A. Morpho-kinetic timings across different embryo groups were compared using Kolmogorov-Smirnov (KS) test and binomial test, and associations with cleavage features were assessed via two-sided Fisher Exact (FS) test. Multi-center and center-specific logistic regression models were calibrated using a subset of data (70%), and their predictive performance was evaluated on independent test data using Area-Under-ROC curve (AUROC) metrics. Main results and the role of chance SA embryos cleaved at significantly slower rate than their euploid siblings in the first 3 cell cycles, from the appearance of the second blastomere t2 (average delay delta=0.49h, KS p = 0.006, fraction of pairs in which SA was delayed compared to euploid sibling F = 54.2%, binomial p = 0.002) up to t8 (delta=2.16h, KS p = 4e-4, F = 57.9%, binomial p = 1e-8). The developmental delay was partially compensated at full blastocyst stage tB (delta=1.71h, KS = 0.0008, F = 57.5%, binomial p = 5e-8). SA timings also differed from WCA ones: SA embryos were significantly slower than their WCA siblings during early cell cycles, with maximum delay reached at t8 (delta=1.67h, KS p = 0.009, F = 55.4%, binomial p = 0.003), but they fully caught-up at tB, with no significant difference observed. These morpho-kinetic patterns were consistently observed in each center separately, but with different effect sizes. The presence of segmental aneuploidies was significantly associated with multinucleation (OR = 1.99, FS test p = 0.05) and morula cell exclusion (OR = 2.69, p = 0.006). A logistic model based on morpho-kinetic data and cleavage features from a single center dataset and regressed against embryo aneuploidy class (euploid vs. SA embryos) displayed adequate predictive performance on independent data from the same center (AUROC=0.70), although predictivity diminished when tested on data from other centers (AUROC=0.52-0.55). Limitations, reasons for caution We cannot rule out inter-center variability in the annotation procedures of morpho-kinetic parameters. Standardized and automated annotation would increase the performance of predictive models and their transferability. Further work is needed to assess whether the morpho-kinetic signal is driven by mitotic errors and if an association with clinical outcomes exists. Wider implications of the findings These findings might help uncovering biological events contributing to preimplantation mosaicism. Moreover, the developed predictive framework might help improving decision-making in PGT-A cycles, providing interpretation for segmental aneuploidies and possibly helping in the evaluation of embryos showing intermediate copy number values for whole chromosomes that are suggestive of mosaicism. Trial registration number Not applicable

0519 Comparing the delta power during titration of INSPIRE therapy and PAP therapy

Abstract Introduction Delta power is a known indicator of sleep drive and sleep pressure. Non-REM sleep delta power is increased in patients with sleep-disordered breathing. Treatment of sleep-related breathing disorder reduces delta power. The purpose of this study is to investigate and compare delta power between individuals on INSPIRE therapy and individuals on PAP therapy. Methods A retrospective review was performed by selecting nine patients who underwent INSPIRE titration study at the MU HealthCare Sleep Disorders Center, between 8/1/2021 and 8/1/2022. Nine patients with similar age and gender who underwent PAP titration study were selected from the database (PolySmith®). Spectral analysis was performed using F4-M1 leads, and delta power was calculated for Stage N3 portion during the last sleep cycle. Results There were 3 patients on INSPIRE who did not have any N3 sleep and those were excluded. Thus, average delta power in 6 patients during INSPIRE titration was 541.88. In contrast, the average delta power for 9 patients during PAP titration was 554.93. Conclusion Results showed that there was minimal difference in patients’ delta sleep during titration of INSPIRE therapy as compared to patients during titration of PAP therapy. However, there were limitations including the amount and timing of N3 sleep, success of titration study, patient’s medications - which may have altered the sleep architecture, and comorbidities such as PLMS (which untreated can affect sleep). Support (if any) The authors have no sources of support to declare.

Student self-efficacy scores improve on twelve career skills with weekly professional skills development assignments in a senior physiology laboratory course

At Michigan State University (MSU), the undergraduate capstone laboratory course for the physiology major places an emphasis on broad development opportunities for students. The course expands on prior knowledge from the undergraduate curriculum with firsthand human physiology activities, but also includes activities on career skills. Since Fall 2019, for six semesters, each weekly homework assignment for the course includes a professional development activity, including self-assessments and reflections on teamwork, leadership style, grit, conflict management, and other key career skills. Deidentified pre- and post-course professional skills surveys were used to assess student perceptions of their proficiency with these skills (n=313). This self-efficacy survey began as a tool for the teaching staff to tailor activities and experiences but became an indicator for self-reported improvements in student professional profiles during the course. The survey consists of twelve questions using five-point Likert scale responses to rank self-efficacy on essential career skills such as contributing to a team, thinking critically, and communicating effectively. Anecdotally, students frequently inform the teaching staff how they directly apply their results from these activities and experiences, sharing their direct use-cases for job, graduate, or professional school applications and interviews. Student feedback reflects how these intentional methods have significant meaning to them by the end of the semester. They often state they were unaware of and would not have worked on professional skills preparation on their own time, either because they were unaware of the tools available, or they did not see the relevance in the current stage of their career. Students reported an improvement in their own professional skills. The greatest improvement over the semester occurs with work-life balance. Although both pre- and post-response averages for this question are lower overall at 3.23 and 3.97 respectively, the delta change is greatest at a 0.73 increase (p&lt;0.001). The highest overall initial average and smallest delta value is on performance integrity. The pre- and post-response averages of 4.31 and 4.61 (delta change of 0.30) implies students already perceive their academic performance as conforming with this professional value. All 12 skills assessed on the survey had significant improvement (p&lt;0.001) when comparing pre- and post-semester responses. The survey concludes with two open-ended questions and deeper assessment of the free response answers is underway. Overall, students perceive improvement in their professional skills by completing in-class assignments. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Prise en charge chirurgicale de la pseudogynécomastie après perte de poids massive : technique de désépidermisation sur mesure assistée par lipoaspiration

After massive weight loss (MWL), the chest in men may show significant deformities. The surgical treatment of gynecomastia after MWL remains a difficult and partially misunderstood surgery due to 4 main factors: a complex excess of skin in height and width that sometimes continues in the axilla or dorsal region, a predominantly fatty rather than glandular component, the malposition of the nipple-areola complex (NAC) that is often enlarged and an inframammary fold (IMF) that is often marked. The techniques currently described are either insufficient or lead to frequent and/or significant complications. The authors describe a new approach that dissociates the treatment of the volume and the skin with a customized resection that is simple, reproducible and safe. Our goal is to improve patient satisfaction while reducing complication rates. Seventeen patients with adipomastia with excess skin after massive weight loss were operated on using liposuction and skin redraping technique. The authors describe the technique, indications and contraindications of the procedure and analyze the results. The average age of the patients was 39 years. The average body mass index (BMI) before weight loss is 42,7kg/m2, the average weight loss before body correction is 49kg, with an average delta of BMI loss of 15,34kg/m2. The average stay in hospital is 1,3 nights. No patient had major complications (hematoma, hemorrhage, necrosis, thrombophlebitis, immediate surgical revision to treat complications). Minor complications including scar dehiscence, infection, steatonecrosis, and distant scar correction were reported in 2 patients, i.e. 11%. Liposuction assisted and desepidermization torsoplasty is a new technique for correction of pseudogynecomastia in MWL patients. The results are reproductible and the complication rates are low. There is no dead space and therefore no drains are needed. There is little pain and a short hospital stay. This technique is simple, quick and easy to learn. However, it is only applicable in adipomastia. A different technique should be used in the presence of firm glandular tissue.

Combustion optimization of a coal-fired power plant boiler using artificial intelligence neural networks

This study establishes detailed neural network modeling procedures for the combustion optimization of a power generation unit, equipped with a Selective Catalytic Reduction (SCR) system. In particular, artificial intelligence neural networks were applied due to its capability in treating large pools of data of great nonlinearity. The objective of this study was to reduce nitrogen oxide (NOx) emissions in the stack gas, lower the cost of emissions compliance and minimize the net unit heat rate at this power generation unit at full-load conditions. These procedures include building a database with real coal power plant operating data, modeling the database and using the genetic algorithm to optimize the operating conditions. The operation is optimized with respect to the steam temperature, selective catalyst reactor, and separated over-fire air conditions. Verifications of the results demonstrated that by carrying out the reported study, the pollutant concentrations of the boiler are significantly decreased and the catalyst layer is effectively preserved, while the operation can be maintained stable near the full-load condition. It was found that the average ammonia (NH3) flow to the SCR under optimized conditions was 229 kg/h, while the average NH3 flow under non-optimal operational conditions was 260 kg/h, resulting in a reduction in NH3 consumption of approximately 12 % from the non-optimized operational condition. In the meantime, the SCR inlet (boiler exit) NOx was reduced from 523 mg/Nm3 (non-optimized operational condition) to 444 mg/Nm3 (optimized operational condition), which represent about 15 % reduction. Based on the experience with SCR from manufactures and operators, the SCR catalyst life expectancy has a direct relationship with the SCR inlet NOx concentration and NH3 injection rate. The lower the NOx concentration at the SCR inlet and the less the NH3 injection rate, the longer of the SCR catalyst life will be. Thus, it is expected that the SCR catalyst layer replacement frequency could be reduced by 10 to 20 % over the normal catalyst replacement cycle, while meeting the same environmental NOx emissions limit. Additionally, a Delta Heat Rate was also calculated using best available data from the optimized operational conditions, including boiler load, boiler excess oxygen (O2), fly ash unburned carbon and attemperation flow. Results were compared with the average Delta Heat Rate calculated from baseline tests. It was found that the average Delta Heat Rate from baseline tests are −60 kJ/kWh, while the delta heat rate from the optimized operation condition hours is −118 kJ/kWh. This represents about 0.57 % improvement on unit heat rate from the baseline average.

Feasibility and impact of a bespoke pre-hospital point of care ultrasound teaching and training programme at London's air ambulance service.

Point-of-care ultrasound has seen an increase in its use in pre-hospital emergency care. There is lack of literature around the training requirement for point-of-care ultrasound of pre-hospital clinicians. This service evaluation assesses the effectiveness of a bespoke hybrid teaching programme. This is a service evaluation of the point-of-care ultrasound teaching programme at London's Air Ambulance from 1 April to 28 May 2021. Subjects' knowledge, image interpretation and confidence were assessed at two different points. Data were gathered using REDCap and exported to Excel for analysis. Mean values and delta were calculated, and t-test was applied for statistical significance. In total, 57 participants were included; out of which 11 were excluded, as they did not complete a post-course survey. Of these, 41.3% participants were point-of-care ultrasound naïve. Mean pre- and post-course scores were 76.5% and 81.7%, respectively, with an average delta improvement of 5.2% (95% confidence interval = 4.70%-5.68%) which was statistically significant (p < 0.002). There was a statistically significant mean improvement of pre- and post-course scores between point-of-care ultrasound naïve and point-of-care ultrasound experienced groups (p = 0.014). Confidence in using point-of-care ultrasound showed mean overall improvement from 2.36/4 to 3.34/4, a mean difference of 0.98 (95% confidence interval = 0.61-1.34), which was statistically significant (p = 0.0039). Our service evaluation highlighted that a hybrid teaching model used by London's Air Ambulance was feasible and had shown significant improvement in the knowledge, image interpretation and confidence of both the point-of-care ultrasound naïve and the PoCUS experienced cohort of clinicians.

Tibio-pedal arterial pressure assessment during endovascular intervention to improve quality-of-life in patients with intermittent claudication.

The aim of this study is to compare the quality-of-life (QOL) outcomes and the tibio-pedal arterial pressure post-endovascular intervention. Physiological assessment of peripheral arterial lesions is infrequently performed during endovascular interventions. We retrospectively reviewed all 343 patients with intermittent claudication who underwent an endovascular intervention via tibio-pedal artery access from October 2018 to May 2021. The baseline and post-intervention tibio-pedal arterial pressures from the pedal sheaths were measured. QOL was assessed using a pre-validated Walking Impairment Questionnaire (WIQ) score before and at 30-day after intervention. We compared the baseline tibio-pedal arterial pressure, post-intervention tibio-pedal arterial pressure, delta pressure (post-intervention minus baseline), baseline WIQ scores, 30-day WIQ scores, and delta score (30-day minus baseline). All 343 patients had successful tibio-pedal accesses. The average tibio-pedal arterial pressure at baseline was 87.0 ± 1.8 mmHg vs. 135.5 ± 1.7 mmHg post-intervention (p < 0.001). Average baseline and 30-day WIQ scores were summation (99.8 ± 3.3 vs. 115.0 ± 3.1, p < 0.001), walking distance (35.7 ± 1.3 vs. 42.5 ± 1.3, p < 0.001), walking speed (21.1 ± 0.9 vs. 23.6 ± 0.8, p = 0.036), stair climbing (4.7 ± 1.4 vs. 24.2 ± 1.4, p = 0.019), and symptoms (18.8 ± 0.2 vs. 20.1 ± 0.2, p < 0.001), respectively. When comparing the increased post-intervention tibio-pedal arterial pressure <60 mmHg vs. ≥60 mmHg, the average delta WIQ scores were all significantly improved with summation (10.0 ± 3.9 to 25.8 ± 5.5, p = 0.01), walking distance (4.1 ± 1.7 to 9.8 ± 2.5, p = 0.02), walking speed (1.5 ± 1.1 to 4.3 ± 1.5, p = 0.02), stair climbing (2.3 ± 1.8 to 9.4 ± 2.5, p = 0.02), and symptoms (1.0 ± 0.3 to 1.8 ± 0.4, p = 0.04), respectively. Increasing the post-intervention tibio-pedal arterial pressure by 60 mmHg can enhance QOL as suggested by improvement of WIQ scores.

Influence of Weather Patterns and Changes on Sickle Cell Disease Vaso-Occlusive Episodes and Acute Chest Syndrome: A Nationwide Sample Analysis

Introduction: Vaso-occlusive episodes (VOE) in sickle cell disease (SCD) contribute to significant morbidity and healthcare costs due to repeated emergency department (ED) visits and hospital stays. Recurrent VOE's also often trigger serious sequelae, such as acute chest syndrome (ACS). Known risk factors for VOE include dehydration and infection. The effect of weather on the incidence of VOE has been studied in specific geographic locations with inconsistent results. Our study aims to determine the correlation between change in weather patterns and VOE nationwide using a large dataset. Methods: After IRB approval, the Pediatric Health Information System (PHIS) database was queried for SCD patients younger than 21 years of age evaluated in the ED or admitted for VOE and ACS from 2016-2021. The PHIS is a comparative database with clinical and resource utilization data for inpatient, ambulatory surgery, ED, and observation unit encounters for more than 49 children's hospitals nationwide. Patients with type HbSS, HbSC, Hb Sβ+, and Sβ(0) SCD were included. Demographic and clinical information was collected, including age, sex, race, geographic location, and inpatient length of stay. Weather information was collected via the National Climatic Data Center database. The weather variables included average temperature (Tavg), delta in temperature (TΔ), average precipitation, and average wind speed for every city in which a pediatric hospital within the PHIS database is located. Descriptive statistics were used to describe the demographics and weather characteristics. Population-averaged GEE analysis with negative binomial distribution with log link was performed with weekly counts of VOE admissions as the outcome, weather parameters as predictors, and hospitals as clusters. The weather parameters used were the averages of the daily units by week. Results from the regression analyses were reported as incidence rate ratios with 95% confidence intervals. A two-sided p-value less than 0.05 was considered as statistically significant for the analysis. Results: Of the total 79, 872 encounters included, 86% were diagnosed with VOE and 14% with ACS. Approximately, 52% of patients presented to hospitals in the southern region (Table 1). Regions (number of participating hospitals) include midwest (MW, 8), northeast (NE, 4), south (S, 11), and west (W, 5). Information from both the PHIS and weather database were available for 11,547 weeks. The south had the highest Tavg, TΔ, and precipitation. The MW had the highest wind speed and lowest Tavg. The NE had the lowest TΔ and Tavg. The west had the lowest wind speed and precipitation. The weather variables remained non-significant for ACS admissions. Overall, Tavg, TΔ, and wind speed were significant for VOE admissions while Tavg, precipitation, and wind speed were significant for VOE ED visits. Table 2 highlights the associations between overall VOE visits, weather variables, and regions. Conclusion: Our results show average temperature and delta in temperature (TΔ) is associated with the incidence of VOE admissions and ED visits. A positive association is observed in the midwest and northeast region for Tavg and negative association in the northeast region for TΔ. Future prospective studies will need to assess the effect of weather on VOE in a larger population, so specific weather-related guidelines can be developed for SCD patients and families. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Novel Mouse Model of TGFβ2-Induced Ocular Hypertension Using Lentiviral Gene Delivery.

Glaucoma is a multifactorial disease leading to irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form and is associated with the elevation of intraocular pressure (IOP). Reduced aqueous humor (AH) outflow due to trabecular meshwork (TM) dysfunction is responsible for IOP elevation in POAG. Extracellular matrix (ECM) accumulation, actin cytoskeletal reorganization, and stiffening of the TM are associated with increased outflow resistance. Transforming growth factor (TGF) β2, a profibrotic cytokine, is known to play an important role in the development of ocular hypertension (OHT) in POAG. An appropriate mouse model is critical in understanding the underlying molecular mechanism of TGFβ2-induced OHT. To achieve this, TM can be targeted with recombinant viral vectors to express a gene of interest. Lentiviruses (LV) are known for their tropism towards TM with stable transgene expression and low immunogenicity. We, therefore, developed a novel mouse model of IOP elevation using LV gene transfer of active human TGFβ2 in the TM. We developed an LV vector-encoding active hTGFβ2C226,228S under the control of a cytomegalovirus (CMV) promoter. Adult C57BL/6J mice were injected intravitreally with LV expressing null or hTGFβ2C226,228S. We observed a significant increase in IOP 3 weeks post-injection compared to control eyes with an average delta change of 3.3 mmHg. IOP stayed elevated up to 7 weeks post-injection, which correlated with a significant drop in the AH outflow facility (40.36%). Increased expression of active TGFβ2 was observed in both AH and anterior segment samples of injected mice. The morphological assessment of the mouse TM region via hematoxylin and eosin (H&E) staining and direct ophthalmoscopy examination revealed no visible signs of inflammation or other ocular abnormalities in the injected eyes. Furthermore, transduction of primary human TM cells with LV_hTGFβ2C226,228S exhibited alterations in actin cytoskeleton structures, including the formation of F-actin stress fibers and crossed-linked actin networks (CLANs), which are signature arrangements of actin cytoskeleton observed in the stiffer fibrotic-like TM. Our study demonstrated a mouse model of sustained IOP elevation via lentiviral gene delivery of active hTGFβ2C226,228S that induces TM dysfunction and outflow resistance.