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1.
Article in English | MEDLINE | ID: mdl-38715897

ABSTRACT

Objectives: Cold snare polypectomy (CSP) is widely performed for small colorectal polyps. However, small colorectal polyps sometimes include high-grade adenomas or carcinomas that require endoscopic resection with electrocautery. This study aimed to evaluate the efficacy and safety of a novel resection technique, hot snare polypectomy with low-power pure-cut current (LPPC-HSP) for small colorectal polyps, compared with CSP and conventional endoscopic mucosal resection (EMR). Methods: Records of patients who underwent CSP, EMR, or LPPC-HSP for nonpedunculated colorectal polyps less than 10 mm between April 2021 and March 2022 were retrospectively evaluated. We analyzed and compared the treatment outcomes of CSP and EMR with those of LPPC-HSP using propensity score matching. Results: After propensity score matching of 396 pairs, an analysis of CSP and LPPC-HSP indicated that LPPC-HSP had a significantly higher R0 resection rate (84% vs. 68%; p < 0.01). Delayed bleeding was observed in only two cases treated with CSP before matching. Perforation was not observed with either treatment. After propensity score matching of 176 pairs, an analysis of EMR and LPPC-HSP indicated that their en bloc and R0 resection rates were not significantly different (99.4% vs. 100%, p = 1.00; 79% vs. 81%, p = 0.79). Delayed bleeding and perforation were not observed with either treatment. Conclusions: The safety of LPPC-HSP was comparable to that of CSP. The treatment outcomes of LPPC-HSP were comparable to those of conventional EMR for small polyps. These results suggest that this technique is a safe and effective treatment for nonpedunculated polyps less than 10 mm.

2.
Article in English | MEDLINE | ID: mdl-38987020

ABSTRACT

INTRODUCTION: Postoperative pulmonary complications (PPCs) vary amongst different surgical techniques. We aim to compare the incidence of PPCs after laparoscopic non-robotic versus laparoscopic robotic abdominal surgery. METHODS AND ANALYSIS: LapRas (Risk Factors for PPCs in Laparoscopic Non-robotic vs Laparoscopic robotic abdominal surgery) incorporates harmonized data from 2 observational studies on abdominal surgery patients and PPCs: 'Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS), and 'Assessment of Ventilation during general AnesThesia for Robotic surgery' (AVATaR). The primary endpoint is the occurrence of one or more PPCs in the first five postoperative days. Secondary endpoints include the occurrence of each individual PPC, hospital length of stay and in-hospital mortality. Logistic regression models will be used to identify risk factors for PPCs in laparoscopic non-robotic versus laparoscopic robotic abdominal surgery. We will investigate whether differences in the occurrence of PPCs between the two groups are driven by differences in duration of anesthesia and/or the intensity of mechanical ventilation. ETHICS AND DISSEMINATION: This analysis will address a clinically relevant research question comparing laparoscopic and robotic assisted surgery. No additional ethical committee approval is required for this metanalysis. Data will be shared with the scientific community by abstracts and original articles submitted to peer-reviewed journals. REGISTRATION: The registration of this post-hoc analysis is pending; individual studies that were merged into the used database were registered at clinicaltrials.gov: LAS VEGAS with identifier NCT01601223, AVATaR with identifier NCT02989415.

3.
Nanotechnology ; 35(40)2024 Jul 19.
Article in English | MEDLINE | ID: mdl-38991512

ABSTRACT

CsPbBr3quantum dots (QDs) have excellent optical properties and good phase stability, but the long-chain ligands on their surfaces affect the charge transfer between QDs. Here, we propose a simple ligand exchange strategy: solution-phase ligand exchange. By adding an acetone solution of phenylethylammonium bromide to the purification process of CsPbBr3QDs, the long-chain ligands were effectively replaced and the electric coupling between QDs was improved. As a result, the power conversion efficiency of the solar cell was increased from 1.95% to 2.83%. Meanwhile, the stability of the devices was significantly improved in the unencapsulated case.

4.
Ultrason Sonochem ; 109: 106990, 2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39018891

ABSTRACT

Starch, lipids, and proteins are key macronutrients in starchy foods. Their interactions during processing can form starch-lipid-protein ternary complexes, significantly affecting food quality. Ultrasonic treatment, as a common processing method, is expected to regulate the quality of starchy foods by influencing the formation of ternary complexes. This study aimed to understand the effect of ultrasonic pretreatment on the formation of starch-lipid-protein ternary complexes using various types of starches. Wheat starch (WS), maize starch (MS), and potato starch (PS) were gelatinized and treated with ultrasound at various power densities (0-40 W/L) to form complexes with lauric acid (LA) and ß-lactoglobulin (ßLG), respectively. Ultrasound increased the amylose content of gelatinized WS, MS, and PS and shifted their chain length distribution towards the short chains. Results from Fourier transform infrared spectroscopy, laser confocal micro-Raman, X-ray diffraction, and differential scanning calorimetry showed that the largest amount of WS-LA-ßLG complexes was formed at the ultrasonic power density of 10 W/L, and MS-LA-ßLG and PS-LA-ßLG complexes at 20 W/L. Additionally, ultrasound enhanced the content of resistant starch (RS) in the starch-LA-ßLG complexes. The RS content increased from 14.12 % to 18.31 % for WS-LA-ßLG, and from 19.18 % and 20.69 % to 27.60 % and 28.63 % for MS-LA-ßLG and PS-LA-ßLG complexes, respectively. This study presents an approach for facilitating the formation of ternary complexes, contributing to the development of low-GI functional foods.

5.
Int J Sports Physiol Perform ; : 1-8, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39019444

ABSTRACT

PURPOSE: Loss of muscle power has a significant impact on mobility in geriatric populations, so this study sought to determine the extent and time course of performance decline in power-centric events throughout the life span via retrospective analyses of masters and elite track-and-field data. METHODS: Four track-and-field events were selected based on maximal power output: the 100-m dash, long jump, high jump, and triple jump. Elite and masters athlete data were gathered from the World Masters Outdoor Championships and the International Amateur Athletic Federation World Athletics Championships (17,945 individual results). Data were analyzed by fitting individual and group results to quadratic and linear models. RESULTS: Average age of peak performance in all events was 27.8 (0.8) years for men and 28.3 (0.8) years for women. Athlete performance decline best matched a linear model for the 5 years following peak performance (mean R2 = .68 [.20]) and for ages 35-60, but best matched a quadratic model for ages 60-90 and 35-90 (mean R2 = .75 [.12]). The average rate of decline for the masters data ages 35-60 ranged from 0.55% per year for men's 100-m dash to 1.04% per year for women's long jump. A significant age × sex interaction existed between men and women, with men declining faster throughout life in all events except the 100-m dash. CONCLUSIONS: Performance decline begins in the early 30s and is linear through middle age. This pattern of decline provides a basis for further research on power-decline pathophysiology and preventive measures starting in the 30s.

6.
ACS Appl Mater Interfaces ; 16(28): 36705-36714, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38958143

ABSTRACT

Great progress has been made in organic solar cells (OSCs) in recent years, especially after the report of the highly efficient small-molecule electron acceptor Y6. However, the relatively low open circuit voltage (VOC) and unbalanced charge mobilities remain two issues that need to be resolved for further improvement in the performance of OSCs. Herein, a wide-band-gap amorphous acceptor IO-4Cl, which possessed a shallower lowest unoccupied molecular orbital (LUMO) energy level than Y6, was introduced into the PM6:Y6 binary system to construct a ternary device. The mechanism study revealed that the introduced IO-4Cl was alloyed with Y6 to prevent the overaggregation of Y6 and offer dual channels for effective hole transportation, resulting in balanced hole and electron mobilities. Taking these advantages, an enhanced VOC of 0.894 V and an improved fill factor of 75.58% were achieved in the optimized PM6:Y6:IO-4Cl-based ternary device, yielding a promising power conversion efficiency (PCE) of 17.49%, which surpassed the 16.72% efficiency of the PM6:Y6 binary device. This work provides an alternative solution to balance the charge mobilities of PM6:Y6-based devices by incorporating an amorphous high-performance LUMO A-D-A small molecule as the third compound.

7.
Sci Rep ; 14(1): 16279, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39009638

ABSTRACT

This article presents the design and implementation of a dipole array antenna based on a radial waveguide power divider for millimeter-wave IoT sensing applications. The dipole array and radial waveguide power divider techniques are used in tandem to achieve high gain with omnidirectional radiation properties. The proposed antenna is comprised of eight non-uniform array dipole structures, a circular radiating loop, and shorting vias. The one-to-eight power divider is created with the shorting vias to feed the circularly arranged eight non-uniform dipole arrays simultaneously. The proposed antenna is simulated and manufactured on Rogers-RO3003C substrate with a thickness of 8 mils. Both simulated and tested results confirm that the proposed method enables the antenna to offer a quasi-omnidirectional pattern with a high peak gain of 5.42 dBi. The antenna offers an impedance bandwidth (S11 < ‒ 10 dB) of more than 1 GHz ranging from 27.93 to 29.13 GHz. Moreover, by optimizing the parameters of the power divider network the proposed antenna can be tuned between a wide bandwidth range of 14.53 GHz as the designed dipole array offering the operating bandwidth from 25.56 to 40.09 GHz. Due to its comprehensive set of performance attributes, particularly for the quasi-omnidirectional radiation characteristics, the presented antenna is a viable candidate for the 5G millimeter wave wireless IoT sensing applications. Additionally, this work will accommodate other researchers to explore the proposed method for developing high-gain omnidirectional antennas for millimeter-wave applications.

8.
Heliyon ; 10(12): e33018, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-39021969

ABSTRACT

Most developing countries' electric power system is stressed by an unprecedented demand growth as well as obstacles that call for urgent actions. Therefore, tackling the present-day power-related challenges and ensure dependable and safe electricity may result in improving living conditions. This research aims to comprehend the primary factors that impede power companies in emerging economies and propose ways of addressing them with a focus on Togolese electricity system as a case study., The methodology utilized to study a complex and dynamic system like electricity sector is an integrated model composed of a survey and review of available literature, an interview with energy experts and the SWOT/PESTLE analysis to perform an in-depth and all-encompassing analysis. The study revealed that the electrification poverty was 39.47 % at countrywide level that requires an additional power of 220.95 MW to that of 2021 to achieve 100 % of electricity access by 2030. Moreover, the system's performance is hindered by a number of internal and external bottlenecks. They include but not limited to limitations in policies and regulations; technical difficulties in the transmission, distribution and off-grid subsystems; insufficient investments; and a lack of incentives and taxes rebates. In light of these findings, a model prioritizing a resilient power system was proposed for transforming the outdated power infrastructure in developing countries laying stress upon energy mix planning, transmission and distribution subsectors innovation and effective regional collaboration.

9.
Ecol Evol ; 14(7): e70002, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39015880

ABSTRACT

Total leaf area per plant is an important measure of the photosynthetic capacity of an individual plant that together with plant density drives the canopy leaf area index, that is, the total leaf area per unit ground area. Because the total number of leaves per plant (or per shoot) varies among conspecifics and among mixed species communities, this variation can affect the total leaf area per plant and per canopy but has been little studied. Previous studies have shown a strong linear relationship between the total leaf area per plant (or per shoot) (A T) and the total number of leaves per plant (or per shoot) (N T) on a log-log scale for several growth forms. However, little is known whether such a scaling relationship also holds true for bamboos, which are a group of Poaceae plants with great ecological and economic importance in tropical, subtropical, and warm temperate regions. To test whether the scaling relationship holds true in bamboos, two dwarf bamboo species (Shibataea chinensis Nakai and Sasaella kongosanensis 'Aureostriatus') with a limited but large number of leaves per culm were examined. For the two species, the leaves from 480 and 500 culms, respectively, were sampled and A T was calculated by summing the areas of individual leaves per culm. Linear regression and correlation analyses reconfirmed that there was a significant log-log linear relationship between A T and N T for each species. For S. chinensis, the exponent of the A T versus N T scaling relationship was greater than unity, whereas that of S. kongosanensis 'Aureostriatus' was smaller than unity. The coefficient of variation in individual leaf area increased with increasing N T for each species. The data reconfirm that there is a strong positive power-law relationship between A T and N T for each of the two species, which may reflect adaptations of plants in response to intra- and inter-specific competition for light.

10.
Article in English | MEDLINE | ID: mdl-39007483

ABSTRACT

Magnetic hyperthermia (MH) has emerged as a promising technology with diverse applications in medical and technological fields, leveraging the remote induction of temperature elevation through an alternating magnetic field. While Fe3O4 nanoparticles with an average size around 12-25 nm are commonly employed in MH systems, this study introduces a strategy to produce smaller particles (less than or equal to 10 nm) with enhanced heating efficiency, as measured by specific power absorption (SPA). We conducted an exhaustive and detailed investigation into the morphological and magnetic properties of CoxFe3-xO4 nanoparticles, aiming to optimize their MH response. By varying the Co content, we successfully tuned the effective magnetic anisotropy while maintaining saturation magnetization nearly constant. The MH analysis indicates that these nanoparticles predominantly heat through the Néel mechanism, demonstrating robust reproducibility across different concentrations, viscosity mediums, and ac field conditions. Notably, we identified an optimal anisotropy or Co concentration that maximizes SPA, crucial for developing magnetic systems requiring particles with specific sizes. This work contributes to advancing the understanding and application of MH, particularly in tailoring nanoparticle properties for targeted and efficient heat generation in various contexts.

11.
Mutagenesis ; 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39021207

ABSTRACT

Systemic oxidative stress stemming from increased free radical production and reduced antioxidant capacity are common characteristics of obese individuals. Using hydrogen peroxide (H2O2) to induce DNA damage in vitro, in peripheral blood mononuclear cells (PBMCs) from obese subjects and controls, the DNA protective ability of dihidroqercetin (DHQ) and biochaga (B) alone or in combination, were evaluated. The effects of DHQ and B were estimated under two experimental conditions: pre-treatment, where cells were pre-incubated with the substances prior to H2O2 exposure; and post-treatment when cells were first exposed to H2 H2O2, and further treated with the compounds. DNA damage was evaluated using the comet assay. The results of pre- and post-treatment showed a significant decrease in DNA damage produced by H2O2 in the obese group. This decrease was not significant in control group probably due to a small number of subjects in this pilot study. More prominent attenuation was noted in the pre-treatment with DHQ (250 µg/mL). Analysis of antioxidant properties revealed that DHQ's remarkable reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, and potent ∙OH scavenging properties may contribute to strong attenuation of H2O2 induced DNA damage. Also, B showed strong reducing power, DPPH, and ∙OH scavenging ability, while reducing power and DPPH scavenger effects were increased in the presence of DHQ. Conclusively, DHQ and B may reduce H2O2-induced DNA damage in PBMCs from obese subjects when challenged in vitro, and could be valuable tools in future research against oxidative damage-related conditions.

12.
Sci Rep ; 14(1): 16297, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39009821

ABSTRACT

A prospective observational study comparing mechanical power density (MP normalized to dynamic compliance) with traditional spontaneous breathing indexes (e.g., predicted body weight normalized tidal volume [VT/PBW], rapid shallow breathing index [RSBI], or the integrative weaning index [IWI]) for predicting prolonged weaning failure in 140 tracheotomized patients. We assessed the diagnostic accuracy of these indexes at the start and end of the weaning procedure using ROC curve analysis, expressed as the area under the receiver operating characteristic curve (AUROC). Weaning failure occurred in 41 out of 140 patients (29%), demonstrating significantly higher MP density (6156 cmH2O2/min [4402-7910] vs. 3004 cmH2O2/min [2153-3917], P < 0.01), lower spontaneous VT/PBW (5.8 mL*kg-1 [4.8-6.8] vs. 6.6 mL*kg-1 [5.7-7.9], P < 0.01) higher RSBI (68 min-1*L-1 [44-91] vs. 55 min-1*L-1 [41-76], P < 0.01) and lower IWI (41 L2/cmH2O*%*min*10-3 [25-72] vs. 71 L2/cmH2O*%*min*10-3 [50-106], P < 0.01) and at the end of weaning. MP density was more accurate at predicting weaning failures (AUROC 0.91 [95%CI 0.84-0.95]) than VT/PBW (0.67 [0.58-0.74]), RSBI (0.62 [0.53-0.70]), or IWI (0.73 [0.65-0.80]), and may help clinicians in identifying patients at high risk for long-term ventilator dependency.


Subject(s)
Ventilator Weaning , Humans , Ventilator Weaning/methods , Male , Female , Prospective Studies , Aged , Middle Aged , Tidal Volume/physiology , Respiration , ROC Curve
13.
Heliyon ; 10(12): e31846, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38952363

ABSTRACT

The Internet of Things communication protocol is prone to security vulnerabilities when facing increasing types and scales of network attacks, which can affect the communication security of the Internet of Things. It is crucial to effectively detect these vulnerabilities in order to improve the security of IoT communication protocols and promptly fix them. Therefore, this study proposes a distributed IoT communication protocol vulnerability detection method based on an improved parallelized fuzzy testing algorithm. Firstly, based on design principles and by comparing different communication protocols, a communication architecture for the distribution network's Internet of Things was constructed, and the communication protocols were formalized and decomposed. Next, preprocess the vulnerability detection samples, and then use genetic algorithm to improve the parallelized fuzzy testing algorithm to perform vulnerability detection. Through this improved algorithm, the missed detection rate and false detection rate can be effectively reduced, thereby improving the security of IoT communication protocols. The experimental results show that the highest missed detection rate of this method is only 4.0 %, and the false detection rate is low, with high detection efficiency. This indicates that the method has good performance and reliability in detecting vulnerabilities in IoT communication protocols.

14.
Heliyon ; 10(12): e32509, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38952384

ABSTRACT

The combination of solid oxide fuel cells (SOFCs) and wood gasification has the potential to significantly increase renewable electricity production and decrease emissions. Depending on the quality of the wood gas, degradation processes have a significant impact on the reliability and lifetime of the SOFC. Using electrochemical impedance spectroscopy (EIS) and subsequent distribution of relaxation times (DRT) analysis, the impact on the degradation of coupling wood gasification with a commercial SOFC stack is determined in this study. The thermal behavior of the SOFC stack under various operating conditions, as well as various synthetic wood gas mixtures classified by their hydrogen-to-carbon (H/C) ratio, was assessed. The decrease in the H/C ratio from 8 to 1, observed during syngas and real wood gas operation, leads to a rightward shift in the Nyquist plots, suggesting an increase in the SOFC stack's impedance. Correlations between variations in the H/C ratio and their effects on anodic electrooxidation, ionic conduction, gas transport, and diffusion were identified using DRT analysis to interpret the EIS results. By incorporating an upstream desulfurization system and ensuring an H/C ratio greater than 2, the coupling of biomass gasification with the SOFC stack was stable to degradation issues.

15.
Front Physiol ; 15: 1298159, 2024.
Article in English | MEDLINE | ID: mdl-38952868

ABSTRACT

Purpose: The present study aimed to investigate a) the associations between bilateral performance utilizing countermovement jump (CMJ), squat jump (SJ), speed and unilateral CMJ, isokinetic peak torque in knee extension and flexion with angular velocities of 60°/s and 180°/s and tensiomyography (TMG) parameters; b) whether the asymmetries derived from unilateral tests are associated with bilateral CMJ, SJ and speed in elite female soccer players. Methods: Thirty-five elite female soccer players (average age: 20 ± 5 years) completed CMJ, SJ, speed, isokinetic muscle strength and TMG tests. Results: Compared to the non-dominant leg, the dominant leg demonstrated greater peak torque output in both knee flexion (7.4%) and knee extension (5.6%) isokinetic tasks, as well as m. vastus medialis contraction time (7.6%), and soccer-specific agility test (4.1%). Conversely, the hamstring to quadriceps peak torque ratio at 180°/s (8.5%) was significantly greater in the non-dominant leg. The associations between CMJ, SJ and speed performance were positive and ranged from weak (r = 0.350) to high (r = 0.710). For speed and TMG-derived variables, correlations were negative and ranged from weak (r = -0.345, p = 0.042, for vastus medialis contraction time) to moderate (r = -0.530, p = 0.001, for biceps femoris contraction time). Furthermore, both bilateral CMJ and SJ negatively correlated with TMG-derived variables, ranging from weak (r = -0.350, p = 0.039, for vastus lateralis contraction time) to moderate (r = -0.537, p = 0.003, for rectus femoris contraction time). Conclusion: The overall significant, albeit inconsistent, correlations between the diverse performance scores obtained highlight the necessity for a multifaceted and thorough diagnostic strategy in female soccer players.

16.
Biol Sport ; 41(3): 231-241, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38952920

ABSTRACT

Despite the importance of strength and power in rugby skills and match outcomes, there exists a noticeable gap in the measurement consistency and estimation of a true change of typical assessments designed to assess these qualities. To address this gap, we investigated the between-session reliability, interrelationships, and minimal detectable changes (MDC) of commonly used strength and power measures in team sports. Sixteen national-level rugby 7 s players were tested on two occasions, one week apart. Both the best and average (of 2-3 trials) peak force, peak power, height, distance, and/or strength indices during countermovement jump (CMJ), drop jump (DJ), isometric mid-thigh pull (IMTP), plyometric push-up (PPU), and standing long jump (SLJ) were obtained. Furthermore, one-repetition maximum (1RM) strength for bench press and back squat, reactive strength index, and dynamic strength index were also determined. Reliability was assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV), and used for MDC calculations, and interrelationships between variables were determined using correlation coefficients. Reliability was excellent for bench press, back squat, and SLJ (ICCs > 0.91); high to excellent for IMTP peak force, all CMJ, and DJ (except best DJ height and contact time), and PPU peak force parameters (ICCs > 0.78), with < 10% CVs (except PPU peak power). MDCs were generally smaller for average than best values. Large to very large relationships (r = 0.60 to 0.85) were observed between bench press, back squat, and IMTP with selected parameters of CMJ and PPU (p < 0.05), but not in DJ and SLJ. In conclusion, selected measures of strength and power displayed high to excellent reproducibility, with average values (rather than best) offering more stable assessments, and "smaller" MDCs. Based upon the relationships, it can be inferred that maximising strength would likely contribute to enhanced explosive performance.

17.
Biom J ; 66(5): e202300197, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38953619

ABSTRACT

In biomedical research, the simultaneous inference of multiple binary endpoints may be of interest. In such cases, an appropriate multiplicity adjustment is required that controls the family-wise error rate, which represents the probability of making incorrect test decisions. In this paper, we investigate two approaches that perform single-step p $p$ -value adjustments that also take into account the possible correlation between endpoints. A rather novel and flexible approach known as multiple marginal models is considered, which is based on stacking of the parameter estimates of the marginal models and deriving their joint asymptotic distribution. We also investigate a nonparametric vector-based resampling approach, and we compare both approaches with the Bonferroni method by examining the family-wise error rate and power for different parameter settings, including low proportions and small sample sizes. The results show that the resampling-based approach consistently outperforms the other methods in terms of power, while still controlling the family-wise error rate. The multiple marginal models approach, on the other hand, shows a more conservative behavior. However, it offers more versatility in application, allowing for more complex models or straightforward computation of simultaneous confidence intervals. The practical application of the methods is demonstrated using a toxicological dataset from the National Toxicology Program.


Subject(s)
Biomedical Research , Biometry , Models, Statistical , Biometry/methods , Biomedical Research/methods , Sample Size , Endpoint Determination , Humans
18.
AAPS J ; 26(4): 77, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38960976

ABSTRACT

Dose-scale pharmacodynamic bioequivalence is recommended for evaluating the consistency of generic and innovator formulations of certain locally acting drugs, such as orlistat. This study aimed to investigate the standard methodology for sample size determination and the impact of study design on dose-scale pharmacodynamic bioequivalence using orlistat as the model drug. A population pharmacodynamic model of orlistat was developed using NONMEM 7.5.1 and utilized for subsequent simulations. Three different study designs were evaluated across various predefined relative bioavailability ratios of test/reference (T/R) formulations. These designs included Study Design 1 (2×1 crossover with T1 60 mg, R1 60 mg, and R2 120 mg), Study Design 2 (2×1 crossover with T2 120 mg, R1 60 mg, and R2 120 mg), and Study Design 3 (2×2 crossover with T1 60 mg, T2 120 mg, R1 60 mg, and R2 120 mg). Sample sizes were determined using a stochastic simulation and estimation approach. Under the same T/R ratio and power, Study Design 3 required the minimum sample size for bioequivalence, followed by Study Design 1, while Study Design 2 performed the worst. For Study Designs 1 and 3, a larger sample size was needed on the T/R ratio < 1.0 side for the same power compared to that on the T/R ratio > 1.0 side. The opposite asymmetry was observed for Study Design 2. We demonstrated that Study Design 3 is most effective for reducing the sample size for orlistat bioequivalence studies, and the impact of T/R ratio on sample size shows asymmetry.


Subject(s)
Cross-Over Studies , Orlistat , Therapeutic Equivalency , Orlistat/pharmacokinetics , Orlistat/administration & dosage , Humans , Sample Size , Research Design , Biological Availability , Models, Biological , Anti-Obesity Agents/pharmacokinetics , Anti-Obesity Agents/administration & dosage , Lactones/pharmacokinetics , Lactones/administration & dosage , Computer Simulation , Dose-Response Relationship, Drug
19.
NMR Biomed ; : e5208, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38961745

ABSTRACT

Filter exchange imaging (FEXI) is a double diffusion-encoding (DDE) sequence that is specifically sensitive to exchange between sites with different apparent diffusivities. FEXI uses a diffusion-encoding filtering block followed by a detection block at varying mixing times to map the exchange rate. Long mixing times enhance the sensitivity to exchange, but they pose challenges for imaging applications that require a stimulated echo sequence with crusher gradients. Thin imaging slices require strong crushers, which can introduce significant diffusion weighting and bias exchange rate estimates. Here, we treat the crushers as an additional encoding block and consider FEXI as a triple diffusion-encoding sequence. This allows the bias to be corrected in the case of multi-Gaussian diffusion, but not easily in the presence of restricted diffusion. Our approach addresses challenges in the presence of restricted diffusion and relies on the ability to independently gauge sensitivities to exchange and restricted diffusion for arbitrary gradient waveforms. It follows two principles: (i) the effects of crushers are included in the forward model using signal cumulant expansion; and (ii) timing parameters of diffusion gradients in filter and detection blocks are adjusted to maintain the same level of restriction encoding regardless of the mixing time. This results in the tuned exchange imaging (TEXI) protocol. The accuracy of exchange mapping with TEXI was assessed through Monte Carlo simulations in spheres of identical sizes and gamma-distributed sizes, and in parallel hexagonally packed cylinders. The simulations demonstrate that TEXI provides consistent exchange rates regardless of slice thickness and restriction size, even with strong crushers. However, the accuracy depends on b-values, mixing times, and restriction geometry. The constraints and limitations of TEXI are discussed, including suggestions for protocol adaptations. Further studies are needed to optimize the precision of TEXI and assess the approach experimentally in realistic, heterogeneous substrates.

20.
Heliyon ; 10(11): e31748, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38961970

ABSTRACT

To build a comprehensive framework for virtual power plant (VPP) development aligned with market dynamics and to devise effective strategies to foster its growth, this study undertakes several key steps. Firstly, it constructs a VPP development framework based on market conditions, to drive the evolution of new power systems and facilitating energy transformation. Secondly, through a blend of theoretical analysis and model construction, the fundamental principles of VPP are systematically elucidated, and a decision model for the VPP development framework, focusing on price demand response, is formulated. Lastly, an optimal scheduling model for the new power system is developed, with its efficacy validated across three distinct scenarios. The findings underscore the critical importance of integrating energy storage technologies, particularly pumped storage hydropower systems, for achieving balance and optimization within new power systems. Model verification reveals that the incorporation of energy storage power stations significantly enhances system stability and efficiency, particularly in addressing the volatility associated with renewable energy sources. Additionally, the analysis indicates that while the adoption of energy storage technologies may marginally increase overall power generation costs, the total power generation cost declines with the integration of battery storage and pumped storage hydropower stations. This suggests that leveraging energy storage technologies not only enhances system operational reliability but also contributes to reducing the overall cost of power production to a certain extent. In summary, this study presents an economic and environmentally sustainable scheduling model for new power systems within the context of market trading environments. By offering both theoretical insights and practical guidance, it aims to support sustainable development and energy transformation initiatives. Ultimately, the study is poised to foster the adoption of clean energy, facilitate the establishment of smart grids, and bolster the sustainable utilization of energy resources, thereby advancing environmental conservation efforts.

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