Changes In Amplitude Research Articles

Improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy

The flexible DC transmission project of renewable energy has become an inevitable development trend for large-scale renewable energy grid connection. Its two-terminal weak feed AC system is often composed of 100 % power electronic power equipment. The fault control strategy is used at both ends of the line to change the fault current characteristics, leading to a decrease in the performance of traditional differential protection. Based on analyzing the adaptability of current differential protection in the two-terminal weak feed AC system under traditional control strategy (TCS), this paper proposed an improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy. Firstly, the fault characteristics of the two terminal weak feed AC systems are analyzed. On this basis, the adaptability of differential protection under TCS is analyzed, and the quantization function that can quantify the operation performance of differential protection is given. Secondly, based on the problem of the traditional negative sequence control strategy, an improved control strategy is introduced and the operation performance of differential protection under the improved control strategy is studied. Finally, an improved differential protection scheme based on the change of current amplitude is proposed. Simulation results show that the proposed protection scheme can resist higher fault impedance(300 Ω) and noise interference(25 dB). In addition, the proposed differential protection scheme is suitable for the protection requirements of the two terminal weak feed AC systems in different scenarios and has higher sensitivity.

Excitation of the bottom-up pathways has no effect on remote muscle fatigue in healthy participants.

The aim of this study is to investigate the effect of induced excitation of the bottom-up pathways at the lateral elbow muscles on local muscle fatigue in the neck region in healthy participants. Eligible participants (n:55) were randomly allocated to an intervention group (n:28) or a control group (n:27). The fatigue of bilateral neck flexor(sternocleidomastoid) and extensor (upper trapezius) muscles was evaluated using surface electromyography, at baseline and immediately post-intervention during a neck flexor and extensor endurance test respectively. Excitation of the bottom-up pathways was performed at multiple lateral elbow muscles in the intervention group by using a temporal summation protocol of mechanical pain, and the pressure pain threshold was determined once in each of the multiple lateral elbow muscles in the control group. Linear mixed model analyses were performed for each outcome measure to evaluate changes over time and within- and between-group differences. No significant "group X time" interaction effects were detected for any of the outcome measures. Significant main effects for time was found for "amplitude over time" of the left upper trapezius (p:0.003) and right sternocleidomastoid muscle (p: 0.013), and for "amplitude changes" of the left upper trapezius muscle (p:0.021). Significant within-group changes were identified in some outcomes in the control group: increased "amplitude over time" of the right sternocleidomastoid muscle (p:0.024) and decreased "amplitude changes" of the left upper trapezius muscle (p:0.024), decreased "normalized median frequency slope over time" of the left UT (p: 0.013). There were no significant within-group changes in the intervention group. No significant between-group differences for any of the outcome measures were found. This study shows no effect of the induction of excitation of the bottom-up pathways at the lateral elbow muscles on the neck muscles' fatigue characteristics compared to a control intervention. Clinical Trial Number: NCT05146960. Date of Registration: December 7, 2021.

Developing a multi-region coupled analysis method for floating offshore wind turbine based on OpenFOAM

As floating offshore wind turbines (FOWTs) continue to scale up in size, the simulation technology for coupling aerodynamic, hydrodynamic, and mooring forces presents significant challenges. This study proposes a multi-region coupled simulation solver, MRFoam, for FOWTs. The multi-region coupled method divides the computational domain into two parts: the turbine region and the floating platform region. This division reduces the number of grid cells and facilitates modular simulations for various structural forms and operating conditions. Compared to the traditional fully coupled method, the multi-region coupled method significantly improves computational efficiency. For various models and grid quantities, the computational efficiency of the multi-region coupled method is nearly double that of the fully coupled method with the results remaining almost identical. Subsequently, the multi-region coupled model is applied for the aerodynamic, hydrodynamic and mooring dynamic analyses of a large-scale FOWT (IEA 15 MW) under various wind and wave conditions. The study found that a decrease in wind speed increases the amplitude of surge response while decreasing the amplitude of heave response. Additionally, at lower wind speeds, an increase in wave height amplifies the platform's motion response, while the variation in aerodynamic thrust is slightly influenced by the change in the platform's motion amplitude.

The Go/No-Go P3 and Depressive Symptoms in Adolescents: Trial-Level Change and Mean Amplitude Relate Differently to Anhedonic Versus Negative Mood Symptoms.

Prior studies have found an association between reduced P3 brain responses-a neural marker of task engagement-and increased depressive symptoms during adolescence. However, it is unclear whether P3 correlates with depression globally, or with certain facets. Existing depression studies have also typically quantified P3 as a cross-trial average, neglecting possible trial-by-trial effects. Among 72 adolescents (44% female), the current study evaluated relations of distinct depression symptom facets-anhedonia and negative mood-with P3s from a three-stimulus go/no-go task, quantified both in average- and trial-level terms. Although no relationship was evident between overall depressive symptoms and average P3 amplitudes, opposing relations were found for each symptom facet with P3 to frequent and infrequent 'go' stimuli: higher anhedonia predicted smaller P3, whereas increased negative mood predicted larger P3. Single-trial, multilevel modeling analyses clarified these effects by showing reduced P3 across stimuli types at task outset, along with greater trial-to-trial attenuation of P3 to infrequent-go stimuli, for adolescents experiencing greater anhedonia. Conversely, increased negative mood was distinctly related to larger P3 at task onset but was unrelated to amplitude change across trials. Results demonstrate differential relations for anhedonic and negative mood symptoms with P3-indicative of task disengagement versus heightened vigilance, respectively-that may be obscured in analyses focusing on overall depressive symptoms. The divergent associations for anhedonia and negative mood with P3 underscore the need to consider these distinct symptom facets in research aimed at clarifying the nature of neural-circuitry dysfunction in depression.

Amplitude versus offset attribute inversion method for characterizing gas hydrate: Insights from high resolution seismic imaging and drilling results in the Shenhu area, South China Sea

AbstractAmplitude versus offset attribute inversion primarily utilizes the change in amplitude with offset to extract lithologic information of the reservoir. We performed high resolution imaging using three‐dimensional seismic data and simulated four different models of gas hydrate and free gas to optimize the selection of sensitive attributes for gas hydrate characterization. We optimized the selection of sensitive attributes for gas hydrate characterization. Our research identified the gradient parameter G as a highly sensitive attribute for characterizing gas hydrate reservoirs. By comparing theoretical models with drilling site data, we predicted the saturation variations of gas hydrate based on the amplitude of G and summarized the amplitude versus offset characteristics and sensitive attributes of gas hydrate at different saturation levels. The results offer valuable insights for identification of gas hydrate in seismic data and provide a reference for their characterization.

Stability and agility trade-offs in spring-wing systems.

Flying insects are thought to achieve energy-efficient flapping flight by storing and releasing elastic energy in their muscles, tendons, and thorax. However, "spring-wing" flight systems consisting of elastic elements coupled to nonlinear, unsteady aerodynamic forces also present possible challenges to generating stable and responsive wing motions. The energetic efficiency from resonance in insect flight is measured by the Weis-Fogh number (N), which is the ratio of peak inertial force to aerodynamic force. In this paper, we present experiments and modeling to study how resonance efficiency (which increases with N) influences the control responsiveness and perturbation resistance of flapping wingbeats. In our first experiments, we provide a step change in the input forcing amplitude to a series-elastic spring-wing system and observe the response time of the wing amplitude increase. In our second experiments we provide an external fluid flow directed at the flapping wing and study the perturbed steady-state wing motion. We evaluate both experiments across Weis-Fogh numbers from 1 < N < 10. The results indicate that spring-wing systems designed for maximum energetic efficiency also experience trade-offs in agility and stability as the Weis-Fogh number increases. Our results demonstrate that energetic efficiency and wing maneuverability are in conflict in resonant spring-wing systems suggesting that mechanical resonance presents tradeoffs in insect flight control and stability.

Non-collinear wave mixing to determine physical ageing in PVC pipelines

The ultrasonic signal amplitudes obtained from non-collinear wave mixing has previously shown significant changes for physically aged Poly-Vinyl Chloride (PVC) pipes, demonstrating the method's effectiveness in assessing the ageing condition of PVC. However, the exact relationship between the measured amplitudes and the extent of physical ageing in PVC has yet to be established. Additionally, it has not yet been validated against established methods or applied to determine the service lifetime of PVC pipes. This study outlines a three-step process to validate the effectiveness of the non-collinear wave mixing technique for assessing the physical ageing of PVC pipelines. Firstly, the non-collinear wave mixing results are compared with the established laboratory method of differential scanning calorimetry, to validate the scattered wave amplitude measurements. Secondly, employing the Arrhenius relation, service lifetime estimates derived from non-collinear wave mixing results align within the expected magnitudes, emphasizing the technique's potential for in-situ pipeline inspections. Finally, a material model is utilized to estimate the Third Order Elastic Coefficient (TOEC) m based on the measured amplitudes, demonstrating a linear correlation with annealing time. A 50% change in TOEC m signifies a brittle state, indicating a high risk of failure. A combination of experimental and analytical analyses highlighted TOEC m variations as the primary factor influencing non-collinear wave mixing amplitude changes during physical ageing. This comprehensive approach also highlights the importance of incorporating diverse factors to precisely forecast and oversee the performance of PVC pipes in real-world environments.

The Influence of Ultrasonic Irradiation of a 316L Weld Pool Produced by DED on the Mechanical Properties of the Produced Component

Additive manufacturing of metallic components often results in the formation of columnar grain structures aligned along the build direction. These elongated grains can introduce anisotropy, negatively impacting the mechanical properties of the components. This study aimed to achieve controlled solidification with a fine-grained microstructure to enhance the mechanical performance of printed parts. Stainless steel 316L was used as the test material. High-intensity ultrasound was applied during the direct energy deposition (DED) process to inhibit the formation of columnar grains. The investigation emphasized the importance of amplitude changes of the ultrasound wave as the system’s geometry continuously evolves with the addition of multiple layers and assessed how these changes influence the grain size and distribution. Initial tests revealed significant amplitude fluctuations during layer deposition, highlighting the impact of layer deposition on process uniformity. The mechanical results demonstrated that the application of ultrasound effectively refined the grain structure, leading to a 15% increase in tensile strength compared to conventionally additively manufactured samples.

Correlation analysis of multifractal stock price fluctuations based on partition function

Studying the correlation analysis of stock price fluctuations helps to understand market dynamics better and improve the scientific nature of investment decisions and risk management capabilities. Most existing methods use multifractals to explore the correlation between different economic entities. However, the study of multifractals fails to fully consider the weight of each entity’s impact on the market, resulting in an inaccurate description of the overall market dynamics. To address this problem, this paper creatively proposes a weighted multifractal analysis method (WMA). The correlation analysis of government regulation, market supply and demand, and stock price index is performed using the data of A-share listed companies in Shenzhen and Shanghai as samples. First, we consider the amplitude fluctuation information the signal carries and weigh the partition function according to the proportion of variance in the segment for different amplitude changes. Secondly, we derive the theoretical analytical form of the classical multifractal model (SMA) of the scaling indicator under WMA. Finally, through numerical simulation experiments, it is confirmed that WMA is equally effective as SMA. In addition, the re-fractal correlation analysis of real financial time series also confirms that WMA can effectively utilize the amplitude fluctuation information in the series and outperforms the classical SMA method in distinguishing different signals.

The moderating role of the late positive potential in the link between attachment anxiety and emotion regulation difficulties.

Understanding how adults experience and regulate their emotions is strongly linked to attachment orientations. Numerous studies indicate emotional regulation difficulties in both attachment avoidance and anxiety. Additionally, emotional Event-Related Potentials (ERPs), such as the Late Positive Potential (LPP), reveal the process of emotional information at the cerebral level, and thus, LPP is commonly used in studies examining emotion regulation processes. For instance, when individuals are asked to use cognitive strategies to increase, maintain, or decrease their emotional responses to stimuli, changes in LPP amplitude can reflect the effectiveness of these regulation strategies. However, little is known about the potential moderating effect of the LPP during the implementation of emotional regulation strategies in the relationship between attachment dimensions and emotional dysregulation. To address this oversight, the purpose of the present study was to examine the association between both dimensions of attachment, anxiety and avoidance, and emotional dysregulation, as well as the moderating role of the LPP during the induced implementation of cognitive reappraisal. Brain activity was recorded using EEG from n = 63 adults while they performed a task in which they were instructed to either reappraise or suppress emotions elicited by unpleasant images. To assess the associations between LPP, emotional dysregulation, and attachment orientations, the Difficulties in Emotion Regulation Scale Spanish version (DERS-E) and the Experiences in Close Relationships questionnaire (ECR-12) were used. Interestingly, we found that greater LPP amplitudes during reappraisal implementation intensified the association between attachment anxiety and emotional regulation difficulties. Conversely, this relationship was non-significant under lower levels of LPP amplitude-Providing supporting evidence for the moderating role of LPP. Our results highlight how attachment anxiety can influence the ability to regulate emotions. This study provides new insights into how variations in LPP contribute to the effectiveness of emotion regulation strategies.

Palynofacies as sea-level-sensitive proxy in Early Cretaceous marine mudstones – A critical evaluation

Stratigraphic distribution patterns of particulate organic matter (POM) have been widely used for facies recognition and paleoenvironmental interpretation as well as to decipher proximal to distal trends within fine-grained sediments. The Lower Cretaceous mudstone-dominated succession in the eastern Lower Saxony Basin (LSB) offers an excellent opportunity to critically evaluate such palynofacies parameters, commonly used to identify transgressive-regressive (T-R) cycles in marine sediments. For the seemingly monotonous succession, a robust sequence stratigraphic framework has been previously established by integrating high-resolution elemental intensity data from X-Ray Fluorescence (XRF) core scanning and biostratigraphy from four drill cores. In this study, the composition and distribution of the POM has been assessed by analysis of 220 strew mounts using transmitted-light microscopy. Overall, the POM composition indicates deposition in a mud-dominated proximal to distal shelf setting. The ratio of opaque versus translucent phytoclasts (OP/TR ratio) shows a distinct long-term increase from the Berriasian onwards with maximum values during the early Hauterivian, followed by a subsequent decrease in OP/TR ratio. This trend broadly reflects the overall T-R evolution of the succession interpreted from Si/Al changes. This also applies to the size and sorting of opaque phytoclasts, with the greatest amplitude changes in opaque particle size parameters being observed in the more proximal deposits of the studied succession. On the other hand, the ratio of terrestrial versus marine palynomorphs (T/M ratio), often applied as indicator of proximal to distal trends and distances from the coastline, shows no correlation with the T-R cycles. Systematic long- and short-term trends visible in T/M ratio correspond to variations in the XRF-derived Ca/Ti stratigraphic trend, which is interpreted to reflect variations in carbonate content. This may indicate that the T/M ratio in the LSB is largely controlled by variations in marine palynomorph flux, probably related to productivity changes of the organic-walled microplankton.

Seismic differences between solar magnetic cycles 23 and 24 for low-degree modes

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every sim 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are a good proxy of the magnetic cycle. In this Letter we investigate solar magnetic activity cycles 23 and 24 through the evolution of the frequency shifts of low-degree modes (ell = 0, 1, and 2) in three frequency bands. These bands probe properties between 74 and 1575 km beneath the surface. The analysis was carried out using observations from the space instrument Global Oscillations at Low Frequency and the ground-based Birmingham Solar Oscillations Network and Global Oscillation Network Group. The frequency shifts of radial modes suggest that changes in the magnetic field amplitude and configuration likely occur near the Sun's surface rather than near its core. The maximum shifts of solar cycle 24 occurred earlier at mid and high latitudes (relative to the equator) and about 1550 km beneath the photosphere. At this depth but near the equator, this maximum aligns with the surface activity but has a stronger magnitude. At around 74 km deep, the behaviour near the equator mirrors the behaviour at the surface, while at higher latitudes, it matches the strength of cycle 23.

Passive RFID integrated acetone sensor and ammonia sensor based on LaFeO3/ZnO/rGO composites

In recent years, with the rapid development of information technology such as the Internet of Things, gas sensors, as gas signal collection devices, have played a vital role in environmental monitoring, industrial and agricultural production, food safety management, medical health diagnosis and air quality monitoring. In industrial production, acetone and ammonia are common chemicals that can leak or exceed safe concentrations, necessitating timely detection and alarm systems to ensure worker safety. Therefore, it is imperative to detect the content of acetone and ammonia, which are widely used and toxic gases. In this paper, a wireless gas sensor based on lanthanum ferrite (LaFeO3)/zinc oxide (ZnO)/reduced graphene oxide (rGO) was proposed and designed to detect acetone and ammonia concentrations at room temperature. The gas sensor with perforations is optimized using HFSS software, and the antenna is fabricated using an engraving machine. Subsequently, the nanocomposite material is coated onto the antenna to complete the gas sensor. The microstructure of lanthanum ferrite/zinc oxide/graphene is characterized and analyzed. Test results demonstrate that the sensor operates within a range of 300 ppm ∼ 1000 ppm for acetone concentration, exhibiting an amplitude change of 16.28 dB and a sensitivity of 0.023 dB/ppm. Furthermore, when operating stably within a range of 150 ppm ∼ 800 ppm for ammonia concentration, the sensitivity of the sensor reaches 0.328 MHz/ppm. Compared to traditional gas sensors, this gas sensor offers advantages such as high detection accuracy, minimal environmental interference factors, excellent selectivity, and prolonged lifespan; presenting promising prospects for detecting toxic gases in laboratories and chemical factories.

Memantine treatment in sickle cell disease: A 1-year study of its effects on cognitive functions and neural processing.

This study evaluates the neurocognitive and electrophysiological effects of 1-year memantine treatment in 14 adolescents and young adults (mean age 24 years) with sickle cell disease (SCD, incluing sickle cell anaemia and sickle cell β-thalassemia), hypothesizing improvements in cognitive functions and neural processing. Participants underwent assessments using subtests from the Wechsler Intelligence Scale and a computerized task-switching paradigm with concurrent event-related potential (ERP) recordings, both before and after the treatment period. Assessments focused on processing speed, working memory, attention and executive function. ERP measurements targeted brain response changes during task switching. Memantine treatment enhanced cognitive test performance, especially in processing speed as shown by the Digit-Symbol Coding and Symbol-Search tests. Results indicated improved visuospatial and graphomotor speed, working memory and attention. The task-switching test revealed reduced error rates, suggesting decreased cognitive load and enhanced executive control. Electrophysiological changes in P1 and P3 amplitudes at frontal and parietal locations post-treatment pointed to more efficient neural processing in tasks requiring cognitive flexibility. These preliminary findings from a Phase II clinical study serve as a 'proof of concept', exploring the feasibility and potential effectiveness of memantine treatment in SCD-a previously uninvestigated context. They support the rationale for more extensive investigations to confirm these results and assess memantine's broader effectiveness.

Application of Geo-Radar in the Detection of Various Adverse Geology in Tunnel Over-advance Geological Forecasting

Abstract Tunnel excavation process will encounter a variety of adverse geological problems, different adverse geologic bodies on the safety of tunneling projects will have more or less impact. This paper summarizes and analyzes several kinds of common adverse geological bodies based on previous engineering examples, and compares and analyzes the prediction results of geo-radar with the actual excavation characteristics in the preliminary over-advanced geological prediction, which shows that different adverse geological bodies such as fracture zones (faults), water-bearing bodies, cavities, joints and fissures development zones, etc., will have an impact on the frequency and amplitude (energy) of radar waves, which will confirm the frequency and amplitude changes of radar waves in the face of the palm. By analyzing the frequency and amplitude changes of radar waves, we can confirm the change of surrounding rocks in front of the palm face. The application of geo-radar in over-advanced geological forecasting and detection of adverse geology has solved the problems encountered in the process of tunnel construction and excavation, and has provided reliable technical support for safe tunnel construction.

Experimental Study of Airfoil Aerodynamic Behavior under Oscillating Motion in Ground Effect

When a flying vehicle approaches a water or land surface, it induces changes in the fluid flow field pattern known as the "ground effect." This research analyzes the ground effect phenomenon, exploring its impact on aerodynamic coefficients and flow patterns around the NACA0012 airfoil in an incompressible subsonic regime under static and dynamic conditions with pitch movements. Numerical simulations and experimental testing in an incompressible subsonic wind tunnel were deployed. The flow field solution is derived from the Navier-Stokes equations, incorporating the Transition SST turbulence model. Initially, the impact of the ground effect phenomenon was investigated at varying distances from the surface in the static state. Subsequently, the airfoil underwent a sinusoidal pitching oscillation at each distance with a specified frequency and amplitude. This allowed for examining its aerodynamic characteristics over time. The static analysis results reveal alterations in the curve's behavior and pressure distribution on the airfoil surface at close distances to the surface. This is attributed to the ground effect phenomenon, which reduces lift force to a certain height and then increases. Dynamic analysis further demonstrates changes in lift coefficient oscillation amplitude. It also exhibits a minimum and maximum lift point phase difference as the airfoil approaches the surface.

Lift enhancement via leading edge vortex delay in flapping flight utilizing kinematic modifications

Flapping-winged micro aerial vehicles (MAVs) are an innovative approach to indoor flight, useful for reconnaissance. However, challenges remain in improving the maneuverability of these drones in low-speed flight, specifically using wing kinematics for different flight profiles. This work focuses on the plunge motion of the SD7003 airfoil in forward flight. Unsteady simulations are carried out at a Reynolds number of 10,000 in Ansys Fluent upon validation against experimental, theoretical, and numerical results from literature. Modification of the kinematics is performed by skewing the sinusoidal curve that dictates the effective angle of attack of the airfoil, leading to what is termed “peak-shifted” (PS) kinematics. The skewness of the curve is varied systematically to delay the peak of plunge velocity during the downstroke. Due to this, the leading edge vortex formation and shedding were also found to be delayed, with stronger vortex cores causing a surge in lift force. Results indicate that with the PS kinematics, mean lift increased by 4.5% and mean drag reduced by 7.9%, at the cost of an increase in power requirement of 42.9% compared to the baseline kinematics. Since lift augmentation and drag reduction are obtained with no change in plunge amplitude or frequency, this opens up opportunities in tail-less MAV design to use PS kinematics in short intervals for maneuvers or flight controls, including roll, pitch, and yaw.

Asteroseismology of Triple-mode Radial δ Scuti Star: TIC 400562821

Abstract We investigated the pulsating behavior of TIC 400562821 using high-precision observations from TESS. Fourier analysis of time-series data revealed three independent frequencies. The period ratios of F to F1 (0.774) and F to F2 (0.625), along with an amplitude change of approximately 0.1 mag, indicate that TIC 400562821 is a triple-mode High-Amplitude δ Scuti (HADS) star. Using the Best Parent Method and the Γ O functions, we identified that the harmonics and sum combination frequencies of F and F1 are caused by the nonlinear response of the stellar medium to pulsation. We also analyzed the amplitude variations of F, F1, and F2. Observational data over 76 days show stable amplitudes for these modes. However, Radial Stellar Pulsations modeling suggests that, over 10,000 cycles, the amplitude of F remains constant, while F1 gradually decreases and F2 approaches zero. This implies that TIC 400562821 may eventually evolve into a single-mode HADS star. Furthermore, asteroseismic modeling was performed, and several effects, such as the mixing-length parameter α MLT and nonadiabatic, were examined on this star. In view of the results by Daszyńska-Daszkiewicz et al. (i.e., α MLT &lt; ∼1 for δ Scuti stars), TIC 400562821 is suggested to be more likely in the post-main-sequence stage, with mass M = 1.34–1.38 M ⊙ and metallicity Z = 0.007–0.008, but still warrants further study to ascertain its nature.

Neuronal basis of high frequency fMRI fluctuation: direct evidence from simultaneous recording.

Resting-state functional magnetic resonance imaging (RS-fMRI) has been extensively utilized for noninvasive investigation of human brain activity. While studies employing simultaneous recordings of fMRI and electrophysiology have established a connection between the low-frequency fluctuation (< 0.1 Hz) observed in RS-fMRI and the local field potential (LFP), it remains unclear whether the RS-fMRI signal exhibits frequency-dependent modulation, which is a well-documented phenomenon in LFP. The present study concurrently recorded resting-state functional magnetic resonance imaging (RS-fMRI) and local field potentials (LFP) in the striatum of 8 rats before and after a pharmacological manipulation. We observed a highly similar frequency-dependent pattern of amplitude changes in both RS-fMRI and LFP following the manipulation, specifically an increase in high-frequency band amplitudes accompanied by a decrease in low-frequency band amplitudes. These findings provide direct evidence that the enhanced high-frequency fluctuations and reduced low-frequency fluctuations observed in RS-fMRI may reflect heightened neuronal activity.

Comparing the Effectiveness of Different Dietary Educational Approaches for Carbohydrate Counting on Glycemic Control in Adults with Type 1 Diabetes: Findings from the DIET-CARB Study, a Randomized Controlled Trial.

Carbohydrate counting is recommended to improve glycemic control in type 1 diabetes (T1D), but the most effective educational methods are unclear. Despite its benefits, many individuals struggle with mastering carbohydrate counting, leading to inconsistent use and suboptimal glycemic outcomes. This study aimed to compare the effectiveness of two group-based programs with individual dietary counseling (standard care) for glycemic control. The trial was a randomized, controlled, open-label, parallel-group design. Adults with T1D on multiple daily insulin injections (MDIs) and with glycated hemoglobin A1c (HbA1c) 53-97 mmol/mol were randomly assigned (1:1:1) to basic (BCC), advanced carbohydrate counting (ACC), or standard care. Primary outcomes were the changes in HbA1c or mean amplitude of glycemic excursions (MAGEs) in BCC and ACC versus standard care after six months. Equivalence testing was performed to compare BCC and ACC. Between November 2018 and August 2021, 63 participants were randomly assigned to BCC (N = 20), ACC (N = 21), or standard care (N = 22). After 6 months, HbA1c changed by -2 mmol/mol (95% CI -5 to 0 [-0.2%, -0.5 to 0]) in BCC, -4 mmol/mol (-6 to -1 [-0.4%, -0.6 to -0.1]) in ACC, and -3 mmol/mol (-6 to 0 [-0.3%, -0.6 to 0]) in standard care. The estimated difference in HbA1c compared to standard care was 1 mmol/mol (-3 to 5 [0.1%, -0.3 to 0.5]); p = 0.663 for BCC and -1 mmol/mol (-4 to 3 [-0.1%, -0.4 to 0.3]); p = 0.779 for ACC. For MAGEs, changes were -0.3 mmol/L (-1.5 to 0.8) in BCC, -0.0 mmol/L (-1.2 to 1.1) in ACC, and -0.7 mmol/L (-1.8 to 0.4) in standard care, with differences of 0.4 mmol/L (-1.1 to 1.9); p = 0.590 for BCC and 0.7 mmol/L (-0.8 to 2.1); p = 0.360 for ACC versus standard care. An equivalence in effect between BCC and ACC was found for HbA1c, but not for MAGEs. Group-based education in BCC and ACC did not demonstrate a clear advantage over individualized dietary counseling for overall glycemic control in adults with T1D. Healthcare providers should consider flexible, patient-centered strategies that allow individuals to choose the format that best suits their learning preferences when selecting the most suitable dietary educational approach.