Function Measurements Research Articles

Eucalyptol Attenuates Cerebral Ischemia/Reperfusion Injury in Mice

Background One of the leading causes of acute brain injury is cerebral ischemia/reperfusion (I/R) injury. It is an ailment that occurs when the brain does not receive enough oxygen-rich blood supply, which damages brain cells. Oxidative stress is recognized as a significant mechanism that causes I/R injury and is a critical focal point for therapy. Apoptosis and inflammation are all pathogenic processes underpinning I/R damage. Eucalyptol (EU), a plant-derived substance, protects neuronal damage. We postulate that EU inhibits apoptosis and oxidative stress after focal cerebral I/R damage in mice. Purpose Thus, the present work sought to examine the neurological protective benefits of EU in mice models of cerebral ischemia/reperfusion (CI/R) injury. Methods The measurement of neurological function, infarct volume, and the amount of water in the brain were evaluated subsequently. The brain tissue was examined to assess the activities of oxidative stress, inflammatory cytokines, and matrix metalloproteinases (MMP) levels, and histopathology was determined. Using enzyme-linked immunosorbent assay (ELISA), apoptotic marker expression was used to measure the levels of B-cell lymphoma 2 (Bcl-2), caspase-3, and Bcl-2 associated X-protein (Bax) proteins that exist as indicators of apoptosis. Results EU treatment malondialdehyde (MDA) levels decreased while glutathione (GSH), superoxide dismutase (SOD), A-TOC, and catalase (CAT) activity increased. Following EU therapy dramatically reduced cerebral dysfunction, which was supported by reduced histological damage in I/R injury. Furthermore, with lower levels of MMP-2 and 9, EU treatment could be a novel approach for preventing CI/R injury. EU-treated mice had a notable reduction in cleaved Bax, caspase-3, and increased Bcl-2 protein activities. EU therapy shields the brain against CI/R injury by inhibiting cell death. Conclusion According to the present study’s findings, EU is a promising neuroprotective agent that can be used to treat CI/R injury in mice. By focusing on these aspects, nurses can provide comprehensive care to patients involved in studies on the effects of EU on CI/R injury, promoting better outcomes through careful monitoring, supportive interventions, and education.

The implications of removing race from interpretation of pulmonary function among persons with or without HIV.

Studies suggest that the use of race-specific pulmonary function reference equations may obscure racial inequities in respiratory health. Whether removing race from the interpretation of pulmonary function would influence analyses of HIV and pulmonary function is unknown. Pulmonary function measurements from 1,067 men (591 with HIV) in the Multicenter AIDS Cohort Study (MACS) and 1,661 women (1,175 with HIV) in the Women's Interagency HIV Study (WIHS) were analyzed. Percent-of-predicted values for spirometry and single-breath diffusing capacity of carbon monoxide (DLCO) measurements were generated with race-specific reference equations derived from the National Health and Nutrition Examination Survey and with the race-neutral application of reference equations derived from the Global Lung Function Initiative database. Regression models were used to evaluate the association between HIV and percent-of-predicted measures of pulmonary function. Alpaydin's F test was used to compare how well these values predicted self-reported respiratory health-related quality of life. Persons with HIV were observed to have significantly lower percent-of-predicted DLCO than those without HIV but no significant differences in spirometric measures of pulmonary function, regardless of whether a race-specific or race-neutral approach was used. Among men, but not women, the race-neutral application of reference equations to generate percent-of-predicted DLCO values performed better for predicting respiratory-related quality of life. The race-neutral application of pulmonary function reference equations continues to identify lung function impairment in persons with or at risk for HIV and, for DLCO, may be superior to the use of race-specific reference equations in identifying clinically relevant impairments.

Quantitative analysis of fetal cardiac structure and function in gestational diabetes mellitus using fetal HQ technology

BackgroundGestational diabetes mellitus (GDM) can contribute to changes in fetal cardiac structure and function, with potential implications for long-term cardiovascular health. This study focuses on assessing these cardiac adaptations in fetuses from GDM pregnancies by using the innovative Fetal Heart Quantification (Fetal HQ) technology to provide a detailed evaluation of structural and functional parameters. MethodsA prospective study was conducted from March 2023 to October 2024 at Xiangyang No.1 People's Hospital, involving 382 pregnant women in their second and third trimesters, including 167 with GDM and 215 healthy controls. Fetal cardiac assessments were performed using Fetal HQ, which allows for direct measurement of cardiac deformation and function. Key parameters such as left ventricular (LV) and right ventricular (RV) dimensions, global longitudinal strain (GLS), and fractional area change (FAC) were analyzed. Maternal clinical data, including blood glucose levels and body mass index (BMI), were also collected. Statistical analyses were performed to compare the cardiac parameters between the two groups. ResultsSignificant differences were observed in fetal cardiac dimensions, with the GDM group exhibiting larger LV end-diastolic area (2.04 ± 0.73 cm2 vs. 1.81 ± 0.69 cm2, p = 0.002) and lower RV GLS (−20.1 ± 5.3 % vs. -22.6 ± 4.6 %, p = 0.000). Other functional parameters, including LV GLS and FAC, did not show significant differences between groups. Correlation analysis revealed a significant positive relationship between maternal HbA1c levels and RV FAC (r = 0.348, p = 0.036), indicating that maternal glycemic control may influence fetal cardiac function. ConclusionsThe findings suggest that GDM is associated with altered fetal cardiac morphology, particularly in the left ventricle, and impaired right ventricular function, as evidenced by reduced GLS. These results highlight the potential impact of maternal hyperglycemia on fetal cardiac development and underscore the importance of monitoring fetal cardiac health in pregnancies complicated by GDM. The use of Fetal HQ technology provides a valuable tool for early detection of cardiac dysfunction in this high-risk population.

Primary Visual Pathway Changes in Individuals With Chronic Mild Traumatic Brain Injury

Individuals with mild traumatic brain injury (TBI) often report vision problems despite having normal visual acuity and fundus examinations. Diagnostics are needed for these patients. To determine if a battery of assessments or machine-learning approaches can aid in diagnosing visual dysfunction in patients with mild TBI. This prospective, observational, case-control study was conducted between May 2018 and November 2021. The study setting was at a level 1 trauma research hospital. Participant eligibility included adult males and females with recorded best-corrected visual acuity and normal fundus examination. Individuals in the case group had a history of mild TBI; controls had no history of TBI. Exclusion criteria included a history of ocular, neurological, or psychiatric disease, moderate-severe TBI, recent TBI, metal implants, age younger than 18 years, and pregnancy. Cases and controls were sex- and age-matched. Data analysis was performed from July 2023 to March 2024. History of mild TBI in the case group. The single-session visit included the Neurobehavioral Symptom Inventory and measurements of oculomotor function, optical coherence tomography, contrast sensitivity, visual evoked potentials, visual field testing, and magnetic resonance imaging. A total of 28 participants (mean [SD] age, 35.0 [12.8] years; 15 male [53.6%]) with mild TBI and 28 controls (mean [SD] age, 35.8 [8.5] years; 19 female [67.9%]) were analyzed. Participants with mild TBI showed reduced prism convergence test breakpoint (-8.38; 95% CI, -14.14 to -2.62; P = .008) and recovery point (-8.44; 95% CI, -13.82 to -3.06; P = .004). Participants with mild TBI also had decreased contrast sensitivity (-0.07; 95% CI, -0.13 to -0.01; P = .04) and increased visual evoked potential binocular summation index (0.32; 95% CI, 0.02-0.63; P = .02). A subset of participants exhibited reduced peripapillary retinal nerve fiber layer thickness, increased optic nerve/sheath size, and brain cortical volumes. Machine learning identified subtle differences across the primary visual pathway, including the optic radiations and occipital lobe regions, independent of visual symptoms. Results of this case-control study suggest that the visual system was affected in individuals with mild TBI, even in those who did not self-report vision problems. These findings support the utility of a battery of assessments or machine-learning approaches to accurately diagnose this population.

Assessing Changes in Motor Function and Mobility in Individuals with Parkinson's Disease After 12 Sessions of Patient-Specific Adaptive Dynamic Cycling.

This pilot randomized controlled trial evaluated the effects of 12 sessions of patient-specific adaptive dynamic cycling (PSADC) versus non-adaptive cycling (NA) on motor function and mobility in individuals with Parkinson's disease (PD), using inertial measurement unit (IMU) sensors for objective assessment. Twenty-three participants with PD (13 in the PSADC group and 10 in the NA group) completed the study over a 4-week period. Motor function was measured using the Kinesia™ sensors and the MDS-UPDRS Motor III, while mobility was assessed with the TUG test using OPAL IMU sensors. The PSADC group showed significant improvements in MDS-UPDRS Motor III scores (t = 5.165, p < 0.001) and dopamine-sensitive symptoms (t = 4.629, p = 0.001), whereas the NA group did not improve. Both groups showed non-significant improvements in TUG time. IMU sensors provided continuous, quantitative, and unbiased measurements of motor function and mobility, offering a more precise and objective tracking of improvements over time. PSADC demonstrated enhanced treatment effects on PD motor function compared to NA while also reducing variability in individual responses. The integration of IMU sensors was essential for precise monitoring, supporting the potential of a data-driven, individualized exercise approach to optimize treatment outcomes for individuals with PD.

Robust frequency-domain acoustic waveform inversion using a measurement of smooth radical function derived from compressive sensing

A smooth radical function derived from compressive sensing is introduced, aiming to measure the misfit in frequency-domain acoustic waveform inversion. The purpose of employing this function is to improve inverse accuracy and reliability. With a novel approximation of L1 norm, the objective function constructed by this measurement can exhibit favorable robustness throughout the inverse iteration. By exploiting the smoothness property, the misfit can be minimized through a cost-effective approach of taking derivatives. The inverse framework of the smooth radical function is derived which indicates comparable computing complexity per iterative step to L2 case, theoretically. The experiential data with outliers are employed for inversion and compared with the traditional optimization-based L1 norm and L2 norm. The obtained results are consistent with theoretical analysis and demonstrate the superiority of the proposed measurement.

Abstract 4131409: Systemic Review and Meta-analysis of Global Longitudinal Strain Changes after Angiotensin Receptor Nephrilysin Inhibitor Initiation in Patients with Heart Failure

Angiotensin Receptor Nephrilysin Inhibitors (ARNi) have been established as a beneficial medication in patients with heart failure (HF). This class of medications has been shown to decrease HF hospitalizations and has been included as one of the pillars in guideline directed medical therapy. Recently, left ventricular (LV) global longitudinal strain (GLS) measurements on echocardiograms have become more common and provide a more precise measurement of LV function than ejection fraction. GLS is now being used as a more intricate way of monitoring improvement in the function of the myocardium, especially in patients with heart failure. This meta-analysis was conducted to determine if treatment with ARNi in HF patients significantly improves myocardial functioning measured by LV GLS. A meta-analysis of 9 studies including observational studies and randomized controlled trials found in a Pubmed search was performed and included patients with heart failure who were initiated on an ARNi for guideline directed medical therapy and had LV GLS measurements taken on an echocardiogram before and after ARNi initiation. The study included patients with heart failure with reduced ejection fraction. Studies were excluded if the patient population did not have a diagnosis of HF and if LV GLS measurements were not available before and after treatment with ARNi. This analysis was performed to determine if initiation of ARNi in patients with HF led to a significant improvement in LV GLS on echocardiography and therefore a significant improvement in myocardial function. There were 9 studies included in the analysis and 879 patients with HF who were treated with ARNi or a control. The change in LV GLS at the conclusion of the study period was measured in both treatment and control groups and the mean difference between the two groups was -1.61 with a 95% confidence interval of (-2.23, -0.98) (p &lt;0.00001). This indicates that the ARNi treatment groups had a significant improvement in GLS compared to the control groups. ARNi initiation was found to significantly improve LV GLS and therefore myocardial function in patients with HF with reduced ejection fraction. LV GLS is a precise measurement of myocardial function. Using this form of measurement in echocardiograms can aid in determining the effect different treatments have directly on myocardial function.

Abstract 4113405: The Role of Cardiac Power Output and Stroke Work Index in Balloon Pulmonary Angioplasty Therapy for Chronic Thromboembolic Pulmonary Hypertension

Background: Right ventricular (RV) and left ventricular (LV) measures of cardiac power output (CPO) and stroke work index (SWI) are existing markers of cardiac function and clinical outcomes. These metrics have not been used to evaluate the effects of balloon pulmonary angioplasty (BPA) therapy in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods: CTEPH patients who underwent at least six BPA sessions and were included in the UC San Diego BPA registry were included for analysis. Left and right ventricular CPO and SWI during each session were recorded. Cardiac output was measured using the thermodilution technique. Differences in continuous variable measurements before versus after BPA therapy were evaluated using the Student T-test. P-value &lt;0.05 was significant. Results: A total of 66 subjects underwent six consecutive BPA sessions (55.5% female, BMI 28.3±6.10kg/m 2 ,16.7% prior pulmonary thromboendarterectomy surgery) and were included for analysis. Measurements of RV function, including RVCPO (Pre-BPA 0.38±0.14 vs Post-BPA 0.30±0.13 W, p=0.001)(Figure 1) and RVSWI (Pre-BPA 16.52±5.09 vs Post-BPA 14.14±4.00 g*m/beat/m 2 , p=0.004) significantly decreased after BPA therapy. Measurements of LV function, including LVCPO (Pre-BPA 1.00±0.32 vs Post-BPA 1.04±0.31 W, p=0.523) (Figure 2) and LVSWI (Pre-BPA 37.13±10.14 vs Post-BPA 39.73±9.37 g*m/beat/m 2 , p=0.152) did not change significantly after BPA therapy. The ratio of LVCPO/RVCPO increased in stepwise fashion from baseline to the last BPA session (2.82± 0.95 vs. 3.54±1.31 W, p&lt;0.001)(Figure 3). Conclusions: Hemodynamic work expended by the RV decreased after BPA therapy, while work expended by the LV remained unchanged during BPA therapy. The ratio of LV-to-RV work increased in a stepwise manner during consecutive BPA sessions. These measurements may be useful parameters to monitor clinical response to BPA therapy.

Abstract 4135301: Cardiac specific gene therapy to treat diabetic heart failure with preserved ejection fraction

Background: We have previously demonstrated that diabetes mellitus (DM) causes cardiac inflammation leading to heart failure with preserved ejection fraction (HFpEF). Arachidonate 5-lipoxygenase (5-LOX), encoded by the ALOX5 gene, is an enzyme that is highly expressed in leukocytes. 5-LOX synthesizes specialized pro-resolving mediators (SPMs) including Resolvin D1 (RvD1), which reduce inflammation. Hypothesis: We hypothesize that cardiac-specific ALOX5 upregulation could prevent diabetes-associated HFpEF without inducing systemic immunosuppression. Methods: DM was induced by feeding mice with a high fat diet (HFD, 60% fat by kcal) starting from 6 weeks of age for 22-24 weeks. At 24 weeks of age, DM mice were treated with RvD1, by intraperitoneal injection at 100 ng/mouse for 2 weeks. To specifically upregulate 5-LOX in the heart, another cohort of DM mice were injected with either AAV9-plain or AAV9- ALOX5 viral vectors under the control of the α-myosin heavy chain (MHC) at 22 weeks old. At 28 weeks, we performed echocardiographic measurement of diastolic function and heart extraction. Results: HFD-induced DM mice showed lower cardiac 5-LOX expression (0.72 ± 0.05 a.u. vs. 1.09 ± 0.12, p &lt; 0.05) and RvD1 levels (1 ± 0.08 vs. 1.9 ± 0.14 fold change over DM mice, p&lt;0.0001) than the mice with normal diet. RvD1 treatment significantly improved DM-associated diastolic function (19.7 ± 1.4 a.u. vs. 22.9 ± 0.4, p&lt;0.05). With cardiac specific upregulation of 5-LOX, cardiac 5-LOX expression (0.89 ± 0.06 vs. 0.70 ± 0.04 a.u., p&lt;0.05) and RvD1 levels were increased (2.1 ± 0.3 a.u. vs. 1.2 ± 0.2, normalized to AAV9-plain, p&lt;0.05). AAV9- ALOX5 also reduced NLRP3 inflammasome activity (0.80 ± 0.02 a.u. vs. 0.90 ± 0.02, p&lt;0.01) and improved DM-associated diastolic dysfunction (17.0 ± 1.2 a.u. vs. 20.5 ± 1.0, p&lt;0.05) without affecting glucose metabolism and obesity in DM mice. Moreover, no alterations of cardiac macrophage infiltration, inflammatory IL1β signaling, or macrophage phenotype were observed in response to cardiac-specific ALOX5 upregulation. Conclusion: In conclusion, both direct RvD1 treatment and cardiac-specific gene therapy to enhance resolution of inflammation in cardiomyocytes reversed DM-associated HFpEF. Gene therapy avoided off-target immunosuppression. Therefore, AAV-directed cardiac ALOX5 upregulation represents a novel cardiac-specific gene therapy for HFpEF that avoids systemic immunosuppression.

Slow global motions in biosolids studied by the deuteron stimulated echo NMR experiment.

Recent 15N R1ρ-relaxation studies have shown that proteins in the solid state undergo slow, low amplitude global motion in the sub-millisecond time range. This range is at the edge of the time window for R1ρ experiments and, therefore, the motional parameters obtained by this method are not precise or reliable. In this paper, we present a 2H stimulated echo study of this type of molecular dynamics. The 2H stimulated echo experiments on a static sample allow for direct measurement of the correlation function in the time range of 10-6-10-1s, making them well suited to study this type of molecular mobility. We have conducted a detailed analytical and numerical comparison of the correlation functions obtained from the relaxation and stimulated echo experiments, which are generally different. We have identified conditions and algorithms that enable a direct comparison of the relaxation and stimulated echo experimental results. Using the protein GB1 in the form of a lyophilized powder, we have demonstrated that 15N R1ρ-relaxation and 2H stimulated echo experiments yield essentially the same slow-motion correlation function. Surprisingly, this type of motion is observed not only in the protein sample but also in the tripeptide and single amino acid solid samples. The comparison of data measured in these three samples at different temperatures led us to conclude that this slow motion is, in fact, ultrasonic phonons, which seem to be inherent to all rigid biological solids.

Application of a large wall electric probe (LWEP) for plasma and ambient gas studies

Abstract The operation of a large wall electric probe (LWEP) is analyzed, where the probe surface area in contact with the plasma is only a few times smaller than the area of the plasma boundaries. Compared to a small standard Langmuir probe (SLP), the LWEP may have significantly greater resolution and sensitivity, but could substantially perturb the plasma and distort the measured properties. A target application for the LWEP is where the sensitivity of the measurement is critical, but the effects of the plasma perturbation is minimal. A specific case where a LWEP may outperform a SLP is the measurement of a nonlocal electron distribution function at energies of electron free diffusion, that is, at energies significantly exceeding thermal electron energies, in order to obtain information about the parameters of the plasma or ambient gas. Examination of the LWEP analysis process has revealed that, depending on the plasma volume and probe configurations, it may be necessary to measure either the first or second derivatives of the probe current with respect to the probe potential to derive the energetic part of the electron energy distribution function.&amp;#xD;

Changes in senescence markers after a weight loss intervention in older adults with obesity

BackgroundUnderstanding how weight loss interventions in older adults with obesity impact aging biology can lay the foundation for targeted, ‘geroscience-based’ interventions. This study examines the association between changes in the senescence-associated secretory phenotypes (SASP) and changes in function in response to a weight loss intervention. MethodsWe conducted a post-hoc biomarker analysis on adults aged ≥ 65 years with body mass index [BMI] ≥30 kg/m2 enrolled in a six-month, non-randomized telemedicine-delivered weight loss intervention. We assessed 16 SASP cytokines using serum samples collected pre-and post-intervention. Clinical outcomes include anthropometric and physical function measurements. A weight loss responder was defined as a loss of ≥5 % of body weight. ResultsMean age was 73.2 ± 3.9 years (73 % female), and BMI was 36.5 ± 5.2 kg/m2. Responders lost 7.6 ± 2.5 %, while non-responders lost 2.0 ± 2.3 % of weight (n = 16 per group, p < 0.001). We observed several significant associations between SASP cytokines and physical function and anthropometric measurement outcomes in age- and sex-adjusted linear models. These included grip strength and Interleukin-8 (IL-8) (b = 9.07) and Insulin-like Growth Factor 1 (IGF-1) (b = 2.6); gait speed and Thymus and Activation-Regulated Chemokine (TARC) (b = 0.46) and IL-7(b = 61 0.11); weight IL-6 (b = -6.77) and IL-15 (b = -2.53); BMI and IL-15 (b = -0.95); waist-to-hip ratio and osteopontin (b = -0.07) (p < 0.05 for all). ConclusionsOur pilot data demonstrated an association between changes in select SASP biomarkers and increased functional ability with intentional weight loss in older adults with obesity. However, findings must be replicated in prospective randomized trials with a control group and additional SASP biomarkers.

LiMAx test and ultrasound elastography to measure biomarkers of declining liver function in patients with liver fibrosis: A correlation analysis.

Monitoring liver changes is crucial in the management of liver fibrosis. Current diagnostic methods include liver function tests such as the Liver Maximum Capacity (LiMAx) test and measurements of liver stiffness. While the LiMAx test quantifies liver function through 13C-methacetin metabolism, ultrasound (US) elastography noninvasively assesses liver stiffness. The relationship between the findings of these methods in patients with liver fibrosis is not fullyunderstood. This study evaluated the correlation between LiMAx measurements of liver function and US elastography-based liver stiffness measurements to better understand the interplay between functional and structural liver parameters in fibrotic liver disease. Additionally, the relationship between body mass index (BMI) and these parameters isevaluated. This retrospective study analysed data from 97 patients who underwent both LiMAx testing and real-time elastography, resulting in a total data set of 108 examinations. The correlations between the results of the LiMAx test and elastography and their relationships with body mass index (BMI) were analysed. There was a significant negative correlation (r = -0.25, p < 0.05) between LiMAx test values and liver stiffness measurements. BMI was significantly negatively correlated with LiMAx values (r = -0.29, p < 0.001) but not significantly correlated with liver stiffness values. This retrospective study confirms the results of previous studies showing a notable but weak association between liver function and liver stiffness. Our results highlight the potential value of both tests as complementary tools for the evaluation of liver health, reinforcing the necessity for a multimodal approach to liver assessment.

Efficacy of whole body vibration on fascicle length and joint angle in children with hemiplegic cerebral palsy.

Enhancing joint range of motion is regarded as one of the most long-term goals in the management of cerebral palsy (CP). With CP, there are well-documented changes in the neurological drive to skeletal muscle, which leads to modifications in the architecture of the muscles. Whole-body vibration (WBV) is one intervention to modify muscle and joint. However, its efficacy needs to be accurately studied. This study investigates the effects of WBV on fascicle length, knee joint angle and function in children with spastic hemiplegic CP. Eighty children with hemiplegic CP aged 4-6years were enrolled. Participants were randomly divided into experimental and control groups. The control group received a designated physical therapy program and the experimental group received a designated physical therapy program in addition to WBV. Program was performed 3 times a week for 12weeks. Goniometry, ultrasonography and gross motor function measurements were used to measure knee extension joint angle, fascicle length of hamstrings and function, respectively. The results of this study indicated that, designed physical therapy program with WBV could increase the active range of motion in knee extension (p=0.001) and fascicle length of hamstring (p=0.001) muscles as well as improve function in children with hemiplegic CP (p=0.001). According to the findings, the use of WBV can be considered as an effective treatment in increasing the range of motion of knee extension and fascicle length and finally improving function in children with CP.

Coarse-grained polarizable soft solvent models, with applications in dissipative particle dynamics.

We critically examine a broad class of explicitly polarizable soft solvent models aimed at applications in dissipative particle dynamics. We obtain the dielectric permittivity using the fluctuating box dipole method in linear response theory and verify the models in relation to several test cases, including demonstrating ion desorption from an oil-water interface due to image charge effects. We additionally compute the Kirkwood factor and find that it uniformly lies in the range gK≃0.7-0.8, indicating that dipole-dipole correlations are not negligible in these models. This is supported by the measurements of dipole-dipole correlation functions. As a consequence, Onsager theory over-predicts the dielectric permittivity by 20%-30%. The mean square molecular dipole moment can be accurately estimated with a first-order Wertheim perturbation theory.

Development of quantitative PET/MR imaging for measurements of hepatic portal vein input function: a phantom study

BackgroundAccurate pharmacokinetic modelling in PET necessitates measurements of an input function, which ideally is acquired non-invasively from image data. For hepatic pharmacokinetic modelling two input functions need to be considered, to account for the blood supply from the hepatic artery and portal vein. Image-derived measurements at the portal vein are challenging due to its small size and image artifacts caused by respiratory motion. In this work we seek to demonstrate, using phantom experiments, how a dedicated PET/MR protocol can tackle these challenges and potentially provide input function measurements of the portal vein in a clinical setup.MethodsA custom 3D printed PET/MR phantom was constructed to mimic the liver and portal vein. PET/MR acquisitions were made with emulated respiratory motion. The PET/MR imaging protocol consisted of high-resolution anatomical MR imaging of the portal vein, followed by a PET acquisition in parallel to a dedicated motion-tracking MR sequence. Motion tracking and deformation information were extracted from PET data and subsequently used in PET reconstruction to produce dynamic series of motion-free PET images. Anatomical MR images were used post PET reconstruction for partial volume correction of the input function measurements.ResultsReconstruction of dynamic PET data with motion-compensation provided nearly motion-free series of PET frame data, suitable for image derived input function measurements of the portal vein. After partial volume correction, the individual input function measurements were within a 16.1% error range from the true activity in the portal vein compartment at the time of PET acquisition.ConclusionThe proposed protocol demonstrates clinically feasible PET/MR imaging of the liver for pharmacokinetic studies with accurate quantification of the portal vein input function, including correction for respiratory motion and partial volume effects.

Measurement of plasma electron energy distribution functions by Langmuir probe using a modified AC modulation method

Abstract In the diagnosis of vacuum discharge plasma using the Langmuir probe, the electron energy distribution function (EEDF) is closely related to the second derivative of current to voltage (d 2 I/dV 2) on the Langmuir probe. While d 2 I/dV 2 is very sensitive to probe noise, its accuracy directly affects the measurement results of the EEDF. In this paper, a modified AC modulation method is proposed to improve the measurement accuracy of the EEDF. First, two small AC signals of different amplitudes are modulated on the measured DC scanning voltage of the Langmuir probe, and the probe current signal is measured. Then, the fundamental amplitudes of the two AC signals are corrected by spectral analysis and using the all-phase fast Fourier transformation—fast Fourier transformation amplitude correction algorithm. Then the accurate first-order derivative of the probe current to voltage (dI/dV) is obtained using the AC modulation derivative correction algorithm, and finally the EEDF is obtained by numerically differentiating dI/dV to obtain d 2 I/dV 2. The method of this paper is compared with the traditional data processing method through experiments, and the results show the superiority and effectiveness of the method.

Peptide Receptor Radionuclide Therapy and clinical associations with renal and hematological toxicities and survival in patients with neuroendocrine tumors: an analysis from two U.S. medical centers

PurposeRenal and hematological toxicity are side effects and dose-limiting factors of Peptide Receptor Radionuclide Therapy (PRRT). We aimed to assess the changes in renal and hematological function and associations with survival in neuroendocrine tumor (NET) patients treated with PRRT.MethodsA retrospective cohort of 448 NET patients treated with either 177Lu-DOTATATE or 90Y-DOTATOC were followed for changes of renal and hematological function. Renal function was assessed by monitoring changes in serum creatinine, blood urea nitrogen and estimated glomerular filtration rate. Hematological function was determined by examining changes in white blood cell counts (WBC), platelet counts, and hemoglobin levels over time. Piecewise linear mixed effect models were applied to model the longitudinal repeated measurements of renal and hematological function. Overall survival (OS) and progression-free survival (PFS) were modelled using Cox proportional hazard regressions.ResultsOf the 448 PRRT treated patients, 335 received 177Lu-DOTATATE (74.78%) and 113 were treated with 90Y-DOTATOC (25.22%). Comparing patients treated with 177Lu-DOTATATE to those treated with 90Y-DOTATOC, renal function did not differ significantly prior to, during or after PRRT. Compared with patients treated with 90Y-DOTATOC, significantly decreased indicators of hematological function were observed in those treated with 177Lu-DOTATATE prior to and during PRRT treatment (WBC: estimate, -0.10, 95% CI, -0.15 to -0.05; P < 0.001; platelet count: estimate, -2.53, 95% CI, -3.83 to -1.24; P < 0.001), and no significant recovery was observed in hematological function post PRRT. Individuals who received 177Lu-DOTATATE tended to have a longer PFS (hazard ratio, 0.47, 95%CI: 0.28–0.79, P = 0.004) compared with 90Y-DOTATOC, but there was no difference in OS.ConclusionThere was no significant renal, but minor hematological toxicity, in patients treated with 177Lu-DOTATATE compared with 90Y-DOTATOC. Compared to 90Y-DOTATOC, 177Lu-DOTATATE appears to enhance PFS, but not OS. Treatment with 177Lu-DOTATATE may necessitate follow-up for hematological toxicity irrespective of other therapies prior to PRRT.

Asian birth cohort studies on allergic diseases: The A2BC network initiative.

The Asia Allergy Birth Cohort (A2BC) network consolidates data from multiple independently established birth cohorts across Asia to enhance research on host-environment interactions in allergic diseases. These cohorts, established at different times with various methodologies, are reliable data sources. Our aim is to introduce the content, variables, and outcomes of these cohorts while highlighting their differences, laying the groundwork for future collaborative research. The A2BC network includes 10 cohort studies on allergic diseases from six Asian countries. Enrollment criteria, study aims, and an initial inventory were discussed and confirmed through five business meetings. A common database was developed to assess the study characteristics of these observational cohorts on allergic diseases, though harmonization efforts are retrospective. Five studies collected data on specific immunoglobulin E responses to various inhalant and food allergens, while six cohorts conducted skin prick tests. Lung function measurements were included in some studies, but without standardized procedures across cohorts. Asthma and allergic rhinitis were primarily assessed using questionnaires or doctor diagnoses, while assessments of eczema and food allergies varied across studies. The A2BC network also examines early-life environmental factors such as delivery mode, antibiotic usage, diet, and air pollutants, although these exposures were measured differently across the cohorts. Despite differences in the origins, methods, and objectives of each cohort, pooling data and conducting joint analyses offer valuable insights into the relationship between environmental exposures and allergic disease outcomes in Asian children. This approach can serve as a foundation for future collaborative research.

Six-month trajectory of phase angle after cardiovascular surgery and associated factors of the recovery during cardiac rehabilitation: A retrospective cohort study

Although the phase angle (PhA), a measure of frailty and sarcopenia, determined by bioelectrical impedance analysis has been reported as a prognostic factor after cardiovascular surgery, few studies have reported the trajectory of the PhA after discharge. In this study, we examined the trajectory of the PhA along with conventional physical function measures and explored the factors associated with recovery for 6 months after hospital discharge in patients who had undergone cardiovascular surgery. We included 116 patients who underwent elective cardiovascular surgery and cardiac rehabilitation after discharge. The PhA, physical function measures (grip strength, knee extension isometric muscle strength [KEIS], and usual gait speed), and Geriatric Nutritional Risk Index (GNRI) were assessed preoperatively, at discharge, and 3 and 6 months. Correlations between the PhA recovery rates and physical function and nutritional indices were assessed using Spearman's correlation analysis. Multivariate linear regression analysis was performed to examine the factors associated with recoveries of PhA and physical function indices (grip strength, KEIS, gait speed) after discharge. Mean values of the PhA and physical function measurements and the GNRI score at discharge were lower than the preoperative values (PhA,-8.0%; grip strength,-8.7%; KEIS,-6.9%; usual gait speed,-8.3%; GNRI,-11%). The grip strength, KEIS, and gait speed recovered to almost preoperative values 3 months after discharge. Values for the PhA and GNRI were still lower than preoperative values 3 months after discharge but had recovered to preoperative values at 6 months. The PhA was not significantly correlated with the recovery rates of the other indicators. Older age was negatively associated with PhA recovery rate, however, recovery rates decreased significantly with post-discharge physical activity. In patients undergoing cardiovascular surgery, the PhA takes longer to recover than muscle strength or gait speed, requiring up to 6 months to recover to preoperative levels. Post-discharge interventions to increase daily physical activity may be an important method of speeding PhA recovery.