bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and optimization of hybrid microgrid energy system: a case study of University of Abuja, Nigeria
Authors: Araoye Timothy Oluwaseun , Ashigwuike Evans Chinemezu , Umar Sadiq Abubakar , Adebayo Taiwo Felix , Egoigwe Sochima Vincent , Odo Matthew Chinedu , Opata Chikammadu Emmanuel , Akachukwu Ohagwu Walte
Published: March 2023

This research work modelled and optimized the hybrid microgrid energy system for electricity generation at the University of Abuja, Nigeria, using PV, wind, diesel, and battery renewable energy resources. The model and optimization of the system are performed through HOMER software. The estimated university average annual power consumption is 2355 kWh/day, and the optimal load demand is 313.40 kWp. The PV/wind/diesel/ converter/battery hybrid system has the lowest cost of energy (COE) of 0.1616 $/kWh, operating cost of $50,592, and net present cost (NPC) of $1,795,026 but diesel/wind/converter/battery hybrid system has highest COE of 0.4242 $/kWh and NPC of $4,710,983. The optimal total electricity generated is 1,272,778 kWh/yr while electricity generated by PV contribute the highest energy of 1,030,485 kWh/yr (81%), whereas diesel generator and wind produced energy of 93,927 kWh/yr (7.38%) and 148,366 kWh/yr (11.7%) respectively. The wind/diesel/converter/battery hybrid system produced carbon dioxide (CO2) of 557,749 kg/yr. The most environmentally friendly is the wind/PV/battery and PV/battery hybrid system without pollutants emissions, but the diesel/wind/battery hybrid system has the highest rate of pollutants emissions. The result shows that PV’s electrical power is extremely high from February to June, which causes a high rate of irradiance within the specified period.
The use of wavy vortex generators in the cooling system to reduce the photovoltaic temperature rise
Authors: Marausna Gaguk , Prasetiyo Erwan Eko , Setiawan Ferry
Published: March 2023

A solar panel will be exposed to sunlight when in use, which causes its temperature to increase. The performance of power production will be impacted if the solar panel's temperature conditions are too hot. High-temperature solar panels can reduce the amount of electrical energy generated. To prevent the temperature of the solar panels from rising too much, a cooling system is required. The proposed solution of this research is a cooling system for solar panels that makes use of heat transfer through water. The solar panels tested in this study have a tilt angle of 20 degrees. The cooling device has dimensions of 400 mm length, 278 mm width, and 20 mm height, with a wavy-type vortex generator positioned in the cooling device mounted on the underside of the solar panel. As a result of the heat flux applied to the top surface of the solar panel, it causes an increase in temperature. The resulting voltage and electric current are reduced. Computational simulations were carried out to determine the performance of the type of vortex generator used. At a cooling water flow rate of 200–600 ml/min, heat transfer with a vortex generator type B works optimally.
Dynamic analysis of grid-connected hybrid wind farm
Authors: Akanto Jannatul Mawa , Islam Md Kamrul , Jahan Effat , Hazari Md. Rifat , Mannan Mohammad Abdul , Rahman Md. Abdur
Published: March 2023

Since the last couple of years, the expansion of grid-connected wind farms (WFs) has increased dramatically. The wind turbine might be a fixed-speed squirrel cage induction generator (FSWT-SCIG) or a variable speed wind turbine with a doubly-fed induction generator (VSWT-DFIG). The main disadvantage of FSWT-SCIG is its lack of ability to adjust power quality. Inversely, the VSWT-DFIG is a competitive wind turbine technology that allows for the effective management of both active and reactive power outputs. Moreover, it has some extraordinary functionaries rather than FSWTSCIG. However, the major downside to this system is that it only has a partial rating AC/DC/AC power converter, which is extremely expensive. Hence, to reduce the overall cost combining the implementation of VSWT-DFIG and FSWT-SCIG in a WF could be a feasible alternative. Therefore, a novel DFIG control technique is proposed in this article, which can keep the connection point voltage of the hybrid WF stable during dynamic analysis. To evaluate the proposed controller responses PSCAD/EMTDC software has been used.
Power management algorithm for standalone operated renewable distribution generator with hybrid energy backup in microgrid
Authors: Gopu Veeranjaneyulu , Nagaraj M.S.
Published: March 2023

In a micro grid system during standalone condition the system may not be stable and might not compensate the required load. Especially for renewable source integrated micro grid system grid disconnected condition is more critical as the renewable sources are unpredictable. The renewable distribution generator needs backup module for support to the loads during standalone condition. In this paper complete distribution network with multiple renewable sources which include PV plant, wind plant and fuel cell source is modeled with power management algorithm (PMA) in only photovoltaic (PV) plant. PMA controls the hybrid backup modules supporting the PV DG. The hybrid backup modules considered for the support are battery unit and super capacitor (SC) unit. The battery and SC units charge or discharge as per the PMA controller with respect to power generated by the PV source. The charge and discharge of these units are dependent on PV power, state of charge (SOC) of battery and SOC of SC. These three sources compensate the critical load connected in the micro grid. A comparative analysis is carried out with and without backup modules and PMA during grid islanding condition on the proposed distribution network. All graphical and parametric comparisons are done using MATLAB/ Simulink software with time domain plots generated by PowerGUI tool.
A new algorithm for fault location in multi-end underground cables using traveling waves
Authors: Tariq Rizwan , Alhamrouni Ibrahim , Rehman Ateeq Ur , Asif Rao Muhammad , Rafique Zimran
Published: March 2023

A quick, reliable, and accurate fault location approach is essential in underground power systems protection. Being the most optimistic research topic of electrical power systems, this article presents an optimized algorithm for fault location in multi-end underground cables using travelling waves. Existing algorithms based on wavelet theory have fewer reliability and accuracy issues that raise an error to the power systems in fault location. The proposed layout presents a multiterminal underground cables system where the entire system is segregated into several fault identification sections where this model identifies the faulty section and the faulty half. Voltage and current wave transient at the mid-point of each fault locator are taken into account to eliminate the time-synchronous error. Traveling waves models are modelled using Bewley diagrams. Detecting the first and second traveling wave transient at both ends of each cable keeps the system reliable. Extensive simulations are simulated using the alternative transient program (ATP) to discriminate, identify, and locate several faults, while the system can also validate the faults near the busbar. The model is developed in MATLAB, and the obtained results depict the proposed algorithm's higher accuracy in fault location.
A comprehensive study of grid impedance and its reliability effects on variable frequency drive
Authors: Pandurangan Ramesh , Palanisamy Kaliannan , Shanmugam Paramasivam
Published: March 2023

Grid impedance is one of the most important parameters for the satisfactory operation of variable frequency drive (VFD) and their interaction with other utilities connected to the same grid. In this research investigation a new approach to analytical evaluation and verification of grid impedance, and short circuit current is discussed. VFD under identical operating and loading conditions is connected to different grid capacities and configurations, being considered in this investigation. Grid impedance variation in terms of measured or estimated values, due to different grid connectivity affects the commutation of uncontrolled front-end rectifiers. This impacts the nonlinearity of input current wave shape, causing a significant change in current harmonics (THDi) and ripple current of DC link. This paper comprehensively investigates the reduction of DC capacitor lifetime and losses of DC inductor, and diode with various grid capacity and configurations under standard load conditions. High-frequency harmonics impact (2-9 kHz) on DC inductor losses is also analyzed. A VFD of 250 kW is considered for entire practical measurement including distortion effects and MATLAB simulation. This research may give a good insight into the sizing of VFD front-end devices. The reliability impact of VFD is also one of the important outcomes of this research.
Design brushless DC motor control by using proportional-integral strategy for a smart storage cabinet system
Authors: Nguyen Quang Dich , Tran Viet Thang , Pham Quang Dang , Giap Van Nam , Trinh Minh Hiep
Published: March 2023

As well know, the use of high technology is more and more encouraged in many countries to decrease the costs, time, and human resources. This paper presents a speed control of brushless DC motor (BLDC), which was applied for the smart storage cabinets. BLDC motor is proposed due to its low costs, high torque, and high performance. The proportional-integral (PI) controller is constructed for the speed control of the movement of cabinet systems. First, the mathematical model and transfer function of the BLDC motor is rewritten to show the structure of the BLDC motor. Second, the proposed PI controller is designed based on the tuning Ziegler-Nichols method and the PI controller is also expressed by the discretized form for BLDC motor. Third, the working principle of BLDC motor is clearly represented and analyzed. Forth, the detail configuration of the experimental system is presented. The STM32 microcontroller unit (MCU) was used to execute. Finally, the experimental test was implemented to validate the power of the proposed controller in practical cases. The experimental results at no-load and load were shown that the power of proportional integral derivative (PID) controller is good at tracking the desired speed signals.
Design and implementation of electrical system morphing wing flight control on prototype light aircraft
Authors: Leonard Christian , Prasetiyo Erwan Eko , Putra Ikbal Rizki
Published: March 2023

This journal discusses the implementation and testing of the electrical morphing wing system on light aircraft prototypes, namely technology on the wing to increase the value of aerodynamic efficiency on the wing surface with experimental methods based on knowledge obtained from various literature sources. Using a configuration of eight servo actuators arranged in parallel for the aileron and flap functions as well as setting and control with a six-channel Flysky-FSi6 remote to control the movement of the master and slave aileron actuators as well as the flap function on the morphing wing. The design includes the layout of the actuator, setting commands on the remote and wiring system electrical components. Other aspects such as rib design, mechanism and material selection affect the overall distribution of motion produced by the servo actuator. Through the design of the electrical system morphing wing design on the prototype aircraft, it is proven to be able to support the needs of the morphing wing motion mechanism with the concept of an arrangement of eight actuators in parallel on the rib morphing wing. It is hoped that the concept of the morphing wing can be implemented and further developed so that it can be used on full-scale aircraft.
Vector-controlled Y-connected three-phase induction motor drives: small-signal stability study during IGBT short-circuit fault
Authors: Naghavi Maryam , Ghanbari Mahmood , Ebrahimi Reza , Jannati Mohammad , Sutikno Tole
Published: March 2023

The stability analysis is one of the most important elements to describe the performance of AC drive systems under both dynamic and steady-state operating circumstances. This is particularly essential because electric motors operate over a wide range of speeds and utilize complex control systems such as field-oriented control (FOC). This study establishes a small-signal stability analysis (SSSA) in a 1-horsepower vector-controlled Y-connected three-phase induction motor (YCTPIM) drive during an insulated gate bipolar transistor short-circuits failure (IGBT-SCF). In the beginning, a vector control system that is based on the indirect rotor FOC (IRFOC) method is described for post-fault functioning of the YCTPIM while the IGBT-SCF is taking place. After that, a small-signal model of the system that has been provided is explored. This model is based on a voltage-current model, and it is constructed by linearizing the non-linear dynamic equations of the system. During IGBT-SCF, an IRFOC strategy as well as SSSA operations are carried out on the 1-HP, 380 V, and YCTPIM. In this research, both analytical and simulation-based methodologies are applied.
Time delay effect reduction on the wireless networked control system using an optimized FOPI-FOPD controller
Authors: Hasan Muhannad Ali , Oglah Ahmed Alaa , Marie Mehdi Jelo
Published: March 2023

Wireless Networked Control System (WNCS) is made up of an actuator, sensor, and controller that communicates through a wireless network rather than typical point-to-point cable connections. Lower maintenance costs, greater flexibility, and increased safety are the main WNCS advantages, so as a result, it has attracted a lot of researchers. Nevertheless, time delays and packet losses in wireless data transmission are classified as complicated problems, which impair WNCS output accuracy and may influence the overall system stability. Integer-Order PI-PD (PI-PD) and Fractional-Order PI-PD (FOPI-FOPD) controllers are proposed to reduce the impact of the control signal transmission's time delay and improve system performance. Matlab Simulink and True-time simulator are used to simulate the WNCS, and ZigBee protocol is used in transceiving the control signal between the controller and the system. Rotary Inverted Pendulum (RIP) acted as the controller's objective. The Grey Wolf Optimization (GWO) technique is utilized to evaluate the best controller parameters. Xbee S2 modules are used to implement the signal transmission process over ZigBee protocol. The FOPI-FOPD controller outperforms the PI-PD controller in the simulation and experimental results in decreasing the influence of time delay on system stability
Self-aligned hybrid carrier-based PWM for modular multilevel converters
Authors: Pham Le Nam , Phan Quoc Dung
Published: March 2023

The self-aligned hybrid carrier-based pulse-width modulation (PWM) for modular multilevel converters (MMC) based on decentralized control is proposed in this paper. It is based on parallel cells in a submodule (SM) using self-aligned hybrid carrier-based PWM, which combines the concept of level-shifted carrier-based PWM (LSC-PWM) and phase-shifted carrier-based PWM (PSC-PWM) methods. By implementing a decentralized control system digitally, hybrid carriers align themselves. Each SM interacts with the other SMs and each parallel cell in an SM communicates with the other cells to generate hybrid carriers. The proposed control strategy makes advantage of the redundancy idea by adding or removing a cell in the case of cell malfunction and system reconfiguration. A current balancing method is incorporated into the decentralized control system to ensure current balance among parallel cells in an SM. The simulation results illustrate the effectiveness of the presented control method in piecewise linear electrical circuit simulation (PLECS) software.
Discontinuous conduction mode approach of ultra-lift DC-DC converter based on three windings coupled inductor
Authors: Hasanzadeh Saeed , Asadi Milad , Sutikno Tole
Published: March 2023

These days, DC-DC boost converters play an essential role in a variety of applications. Therefore, a variety of techniques were proposed in the literature to achieve the highest voltage gain. A large number of passive elements are typically used in high-voltage DC-DC converters. Increasing the order of the system would make modeling and controlling the output voltage of the converter more complex. This paper examines an ultra-lift DC–DC converter using a three-winding inductor and a super-lift construction in discontinuous conduction mode (DCM). This converter provides substantial voltage gain by utilizing the three-winding coupling inductor topology without increasing the duty cycle or passive circuit parts. Because the DCM operation mode occurs in the converter, it is necessary to investigate and analyze it. The DCM operation mode of an Ultra-Lift converter is examined in this study, and then simulation results are shown to validate the equations.
Robust current-mode control of bridgeless single-switch SEPIC PFC converter
Authors: Al-Baidhani Humam , Sahib Abdullah
Published: March 2023

In this paper, the nonlinear model of the bridgeless single-switch ac-dc  single-ended primary-inductor converter (SEPIC) in discontinuous conduction mode is derived. In addition, a robust control method is introduced to accommodate the variations in input voltage and load current. The current-mode controlled power converter is designed to operate in buck and boost modes. The proposed closed-loop SEPIC converter is simulated in MATLAB to validate the design approach. The current-mode control scheme is also compared with the conventional voltage-mode controller. It is confirmed that the proposed control scheme exhibits precise tracking performance and enhanced transient response under large disturbances.
El colectivo feminista en la Convención: estrategias y logros
Authors: Guzmán Virginia
Published: March 2023

Este artículo analiza la actuación del colectivo feminista conformado en la Convención Constitucional chilena, elegida en mayo del año 2021 con el fin de elaborar una propuesta de nueva Constitución, que debía ser entregada en junio de 2022 para ser sometida a un plebiscito de ratificación. Se analizan las estrategias desplegadas para legitimar la agenda feminista, articularla con los debates más amplios referidos al Estado, el sistema político, los derechos fundamentales y el sistema de justicia. La acción de este colectivo movilizó la agenda feminista construida en distintos espacios de la sociedad civil, de la academia y de la política; conectó las distintas expresiones del feminismo en la Convención y fue bisagra entre los movimientos sociales y el debate convencional durante todo el proceso.
Muchos de odios y variaciones sobre un mismo discurso
Authors: Adrián Tamara
Published: March 2023

En los últimos diez años, las estrategias usadas por los grupos conservadores, particularmente con base religiosa, para impedir o revertir la existencia de regulaciones sobre derechos sexuales y reproductivos e igualdad por orientación sexual e identidad de género han cambiado sustancialmente. Se ha pasado del uso del discurso religioso –que no ha desaparecido — al uso de discursos supuestamente científicos, proferidos de forma simultánea, aunque aparentemente separada, por organizaciones no gubernamentales provida, ciertos grupos feministas y algunas organizaciones políticas. Este artículo pretende aclarar esta evolución para poder enfrentarla adecuadamente.
The Effects of Acoustic and Semantic Enhancements on Perception of Native and Non-Native Speech
Authors: Kato Misaki , Baese-Berk Melissa M.
Published: March 2023

Previous research has shown that native listeners benefit from clearly produced speech, as well as from predictable semantic context when these enhancements are delivered in native speech. However, it is unclear whether native listeners benefit from acoustic and semantic enhancements differently when listening to other varieties of speech, including non-native speech. The current study examines to what extent native English listeners benefit from acoustic and semantic cues present in native and non-native English speech. Native English listeners transcribed sentence final words that were of different levels of semantic predictability, produced in plain- or clear-speaking styles by Native English talkers and by native Mandarin talkers of higher- and lower-proficiency in English. The perception results demonstrated that listeners benefited from semantic cues in higher- and lower-proficiency talkers’ speech (i.e., transcribed speech more accurately), but not from acoustic cues, even though higher-proficiency talkers did make substantial acoustic enhancements from plain to clear speech. The current results suggest that native listeners benefit more robustly from semantic cues than from acoustic cues when those cues are embedded in non-native speech.
Investigating the specific absorption rate and antimicrobial activity of Mn0.25Fe2.75O4/Ag ferrogel based on carboxymethyl cellulose/polyvinyl alcohol composite polymer
Authors: Sunaryono Sunaryono , Chusna Nadiya Miftachul , Hidayat Muchlis Fajar , Choerullah Andy , Hidayat Samsul , Mufti Nandang , Aripriharta Aripriharta , Afandi Arif Nur , Rajagukguk Juniastel , Malek Nik Ahmad Nizam Nik , Taufiq Ahmad
Published: March 2023

Carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA)-Mn0.25Fe2,75O4/Ag ferrogels was fabricated by using the freezing-thawing method. Mn0.25Fe2.75O4/Ag magnetic fillers of ferrogels were synthesized by using coprecipitation and chemical reduction methods. Characterization of Mn0.25Fe2.75O4/Ag nanopowders was carried out using X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM) instrument, and antimicrobial activity. At the same time, CMC/PVA-Mn0.25Fe2.75O4/Ag ferrogels were characterized by using magnetothermal instrument. The XRD pattern of the magnetite filler shows the peaks by the Fe3O4 and Ag phases, respectively. The TEM image, there are Mn0.25Fe2.75O4 and Ag with particle size distributions of 5–7 and 10–13 nm, respectively. The hysterical curve from VSM characterization shows a decrease in the value of magnetization saturation from 16.9 to 14.7 emu/g along with the addition of Ag material. Antimicrobial activity was tested using the agar diffusion method. Mn0.25Fe2.75O4/Ag samples showed very good results indicated by the widening of the zone of inhibition around the sample. Thus, CMC/PVA-Mn0.25Fe2.75O4/Ag ferrogels has the potential application to be applied in hyperthermia therapy as well as antimicrobial materials.
Role of suction/injection with magnetic dipole and double diffusion on nonlinear radiative Eyring–Powell nanofluid
Authors: Jabeen Kanwal , Mushtaq Muhammad , Naeem Sahar
Published: March 2023

The purpose of the current work is to explore the outcome of suction/injection on Eyring–Powell’s non-linear radiation nanofluid. Non-Newtonian nanofluid flow has a variety of uses in the production of electrical devices, pharmaceuticals, medical equipment, glass fiber, polymer sheets, and more. We considered the Eyring–Powell fluid over an extending surface in the mechanism of a magnetic dipole with double diffusion, and activation energy, because of all these potential consequences. Nonlinear partial differential equation’s together with the supporting constraints are converted into nonlinear ordinary differential equation’s by a suitable similarity function. The obtained equations are solved numerically or analytically by using software MATLAB and MAPLE. This whole analysis is described by the effects of steady, laminar, and incompressible flow. By analyzing these combined effects, we can improve the thickness of the thermal boundary layer. The thermophoresis and Brownian properties that are specifically examined are elaborated by the Buongiorno model. The physical restraints, such as ohmic and viscous dissipation, as well as numerous other parametric factors, are depicted together with their final impacts on fluid flow. For both suction/injection skin friction coefficient decreases with the rise in [Formula: see text] ferromagnetic interaction parameter and Hartman number Ha. The thermal profile is inversely associated with the Prandtl number. The physical behavior of this flow problem in tabular and graphical form, agrees very well with the work already published. Some applications of this research are dosing pumps, vacuum suction machines, etc. To preserve this work, an absolute differentiation is considered that determines the validity of the current work.
Experiences of Legally Blind Individuals at Different Stages of the Employment Cycle as These Relate to Section 503 of the Rehabilitation Act
Authors: Tarantino Marco , Reyes Jared
Published: March 2023

The most recent data on the labor force participation rate of individuals who identify as being blind or having vision loss in the United States indicate it is approximately 44%. In 2014, the Office of Federal Contract Compliance Programs promulgated regulations pertaining to Section 503 of the Rehabilitation Act of 1973 to address the continued lack of employment opportunities for individuals with disabilities. These reforms had the potential to expand individuals with disabilities’ employment horizons as it was estimated that the number of employees who work directly under a federal contract number in the millions. Five years later, it is unclear how federal contractors are implementing these alterations to recruit and retain legally blind individuals. Using quantitative analysis of responses from 140 current/former legally blind employees and job applicants, this research measured the current employment outcomes of the legally blind community in relation to the Section 503 regulations update. Gaps in employment for legally blind individuals existed, especially in regards to the job classifications in which they found the most success and whether the position held was disability-oriented. These results will inform HR professionals, policymakers, and blind advocates on how to proceed in developing effective disability-conscious workplace laws and policies.
Transit’s Financial Prognosis: Findings from a Survey of U.S. Transit Systems during the COVID-19 Pandemic
Authors: Siddiq Fariba , Wasserman Jacob L. , Taylor Brian D. , Speroni Samuel
Published: March 2023

The COVID-19 pandemic occasioned significant financial distress and uncertainty for many U.S. transit operators. In the face of this crisis, the federal government provided substantial supplemental operating support. To understand how this fiscal turmoil and relief have affected U.S. transit systems, we conducted two nationwide surveys of transit agency staff in 2020 and 2021-2022. While pandemic-induced financial shortfalls affected service in 2020, with capital projects delayed too, these effects became much more muted by 2021/2022. Most systems reported moderate to substantial increases in federal funding during the pandemic, more so than other funding categories. However, nearly half foresee financial shortfalls once federal relief funding expires. Agencies with higher pre-pandemic ridership and farebox recovery are particularly affected by fare revenue losses and more likely to anticipate shortfalls. In the near term, difficulty hiring and retaining front-line workers was a pressing concern, while very few had plans to maintain pandemic fare suspensions.
Charrettes for success – A case study of a collaborative workshop approach to driving curriculum change to address awarding gaps
Authors: Dunbar-Morris Harriet
Published: March 2023

This case study presents the ‘charrette model’ based on work undertaken by the University Alliance (UA), but refined and implemented at the University of Portsmouth to address a key university objective to address awarding gaps between graduates of different ethnicities. First the model, and how it can be used to bring staff and students together to co-create solutions to awarding gaps, will be introduced. The model focuses on what happens in teaching spaces and curricula. We first outline how the UA developed and brought to ‘proof of concept’ a ‘sandpit’ focused on innovative curriculum development for the 21st century. Then the model was further developed as a ‘charrette’ for course teams and students to work together to address the awarding gap at university level. The case study goes on to present further development, where charrette participants concentrate on bespoke and tailored changes at course and subject level, and work with student ambassadors in a focused way. Finally, lessons learned from the roll-out of the charrette model are presented, along with plans for future development. The case study is intended to provide insight for how to implement a similar initiative in other institutions.
Mitochondrial pyruvate dehydrogenase kinases contribute to platelet function and thrombosis in mice by regulating aerobic glycolysis
Authors: Flora Gagan D. , Nayak Manasa K. , Ghatge Madankumar , Kumskova Mariia , Patel Rakesh B. , Chauhan Anil K.
Published: March 2023

Resting platelets rely on oxidative phosphorylation (OXPHOS) and aerobic glycolysis (conversion of glucose to lactate in the presence of oxygen) for their energy requirements. In contrast, platelet activation exhibits an increased rate of aerobic glycolysis relative to OXPHOS. Mitochondrial enzymes pyruvate dehydrogenase kinases (PDKs) phosphorylate the pyruvate dehydrogenase (PDH) complex to inhibit its activity, thereby diverting the pyruvate flux from OXPHOS to aerobic glycolysis upon platelet activation. Of 4 PDK isoforms, PDK2 and PDK4 (PDK2/4) are predominantly associated with metabolic diseases. Herein, we report that the combined deletion of PDK2/4 inhibits agonist-induced platelet functions, including aggregation, integrin αIIbβ3 activation, degranulation, spreading, and clot retraction. In addition, collagen-mediated PLCγ2 phosphorylation and calcium mobilization were significantly reduced in PDK2/4−/− platelets, suggesting impaired GPVI signaling. The PDK2/4−/− mice were less susceptible to FeCl3-induced carotid and laser-induced mesenteric artery thrombosis without any effect on hemostasis. In adoptive transfer experiments, thrombocytopenic hIL-4Rα/GPIbα-transgenic mice transfused with PDK2/4−/− platelets exhibited less susceptibility to FeCl3 injury–induced carotid thrombosis compared with hIL-4Rα/GPIbα-Tg mice transfused with WT platelets, suggesting a platelet-specific role of PDK2/4 in thrombosis. Mechanistically, the inhibitory effects of PDK2/4 deletion on platelet function were associated with reduced PDH phosphorylation and glycoPER in activated platelets, suggesting that PDK2/4 regulates aerobic glycolysis. Finally, using PDK2 or PDK4 single KO mice, we identified that PDK4 plays a more prominent role in regulating platelet secretion and thrombosis compared with PDK2. This study identifies the fundamental role of PDK2/4 in regulating platelet functions and identifies the PDK/PDH axis as a potentially novel antithrombotic target.
Imaging and histological evaluation of the long head of the biceps tendon in the presence of different types of rotator cuff tears
Authors: Kajiwara Daisuke , Ochiai Nobuyasu , Hashimoto Eiko , Hirosawa Naoya , Akimoto Koji , Nojima Daisuke , Shimada Yohei , Ise Shohei , Ohtori Seiji
Published: March 2023

Background

A comparison of changes in the long head of the biceps tendon for different types of rotator cuff tears has not been previously performed. Furthermore, the correlation between the thickening and degeneration of the long head of the biceps tendon and the cause of these changes have not been fully clarified. We evaluated the relationship between degenerative changes in the long head of the biceps tendon and rotator cuff tears in a rat model using imaging and histology.

Methods

Ninety-six 12-week-old Sprague–Dawley rats were divided into anterior (subscapularis tear), anterosuperior (subscapularis, supraspinatus, and infraspinatus tears), superior (supraspinatus and infraspinatus tears), and control groups. The long head of the biceps tendon was harvested at 4 or 12 weeks postoperatively. The cross-sectional areas of the intra- and extra-capsular components of the tendon were measured using micro-computed tomography, and the affected/normal ratio of the cross-sectional area was calculated. Masson’s trichrome staining and Alcian blue staining were performed for histologic analysis, with degenerative changes described using the modified Bonar scale. The correlation between the affected/normal ratio and Bonar scores was evaluated.

Results

The affected/normal ratio was higher for the anterior and anterosuperior groups than for the control group at 4 and 12 weeks. The ratio increased for the intra-articular portion in the superior group and for both the intra- and extra-articular portions in the anterior and anterosuperior groups. Degeneration considerably progressed in the anterior and anterosuperior groups compared with the control group from weeks 4 to 12 and was greater in the intra- than in the extra-articular portion. The ratio correlated with extracellular matrix score.

Conclusions

Subscapularis tears were associated with progressive thickening and degeneration of the long head of the biceps tendon at 4 and 12 weeks postoperatively, which was more significant in the intra- than in the extra-articular portion. Histologic evaluation indicated that the extracellular matrix likely caused these degenerative changes.
Synthetic mesh versus biological mesh to prevent incisional hernia after loop-ileostomy closure: a randomized feasibility trial
Authors: Mäkäräinen Elisa J , Wiik Heikki T , Kössi Jyrki AO , Pinta Tarja M , Mäntymäki Leena-Mari J , Mattila Anne K , Kairaluoma Matti VJ , Ohtonen Pasi P , Rautio Tero T
Published: March 2023

Background

Incisional hernia is a frequent complication after loop-ileostomy closure, rationalizing hernia prevention. Biological meshes have been widely used in contaminated surgical sites instead of synthetic meshes in fear of mesh related complications. However, previous studies on meshes does not support this practice. The aim of Preloop trial was to study the safety and efficacy of synthetic mesh compared to a biological mesh in incisional hernia prevention after loop-ileostomy closure.

Methods

The Preloop randomized, feasibility trial was conducted from April 2018 until November 2021 in four hospitals in Finland. The trial enrolled 102 patients with temporary loop-ileostomy after anterior resection for rectal cancer. The study patients were randomized 1:1 to receive either a light-weight synthetic polypropylene mesh (Parietene Macro™, Medtronic) (SM) or a biological mesh (Permacol™, Medtronic) (BM) to the retrorectus space at ileostomy closure. The primary end points were rate of surgical site infections (SSI) at 30-day follow-up and incisional hernia rate during 10 months’ follow-up period.

Results

Of 102 patients randomized, 97 received the intended allocation. At 30-day follow-up, 94 (97%) patients were evaluated. In the SM group, 1/46 (2%) had SSI. Uneventful recovery was reported in 38/46 (86%) in SM group. In the BM group, 2/48 (4%) had SSI (p > 0.90) and in 43/48 (90%) uneventful recovery was reported. The mesh was removed from one patient in both groups (p > 0.90).

Conclusions

Both a synthetic mesh and biological mesh were safe in terms of SSI after loop-ileostomy closure. Hernia prevention efficacy will be published after the study patients have completed the 10 months’ follow-up.
Sexual dysfunction worsens both the general and specific quality of life of women with irritable bowel syndrome. A cross-sectional study
Authors: Camacho Santiago , Díaz Andrea , Pérez Paulina , Batalla Héctor , Flores Yoshua , Altamirano Evelyn , Higuera-de la Tijera María de Fátima , Murguía Daniel , Gómez-Laguna Laura
Published: March 2023

Background

Irritable bowel syndrome (IBS) and sexual dysfunction (SxD) lowers quality of life (QOL) separately, but the effect of their overlap in unselected populations has not been studied.

Objective

To evaluate the QOL of IBS women with and without SxD and compare it with controls.

Methods

In this cross-sectional assessment, we studied 51 IBS women (Rome IV criteria) and 54 controls. SxD was determined using the female sexual function index questionnaire. QOL was evaluated by the Short Form 36 (SF-36) and IBS-QOL questionnaires.

Results

SxD prevalence was similar between IBS women (39.22%) and controls (38.89%). Compared with other groups, IBS patients with SxD showed lower scores in all domains as well as in the physical, mental summaries of the SF-36 and almost all domains (except for body image, food avoidance, and social reaction compared with IBS patients without SxD) and the total score of IBS-QOL.

Conclusions

These findings show that SxD worsens both general and specific QOL of women with IBS. The consideration of SxD in patients with IBS will allow us to make a more effective diagnostic and therapeutic approach. Clinical trial registry in Mexico City General Hospital: DI/19/107/03/080. Clinical trials registration: NCT04716738.
A decade of faculty development for health professions educators: lessons learned from the Macy Faculty Scholars Program
Authors: Haas Mary , Triemstra Justin , Tam Marty , Neuendorf Katie , Reckelhoff Katherine , Gottlieb-Smith Rachel , Pedigo Ryan , McTaggart Suzy , Vasquez John , Hundert Edward M. , Berkowitz Bobbie , Humphrey Holly J. , Gruppen Larry D.
Published: March 2023

Faculty development (FD) programs are critical for providing the knowledge and skills necessary to drive positive change in health professions education, but they take many forms to attain the program goals. The Macy Faculty Scholars Program (MFSP), created by the Josiah Macy Jr. Foundation (JMJF) in 2010, intends to develop participants as leaders, scholars, teachers, and mentors. After a decade of implementation, an external review committee conducted a program evaluation to determine how well the program met its intended goals and defined options for ongoing improvement.

The committee selected Stufflebeam’s CIPP (context, input, process, products) framework to guide the program evaluation. Context and input components were derived from the MFSP description and demographic data, respectively. Process and product components were obtained through a mixed-methods approach, utilizing both quantitative and qualitative data obtained from participant survey responses, and curriculum vitae (CV).

The evaluation found participants responded favorably to the program and demonstrated an overall increase in academic productivity, most pronounced during the two years of the program. Mentorship, community of practice, and protected time were cited as major strengths. Areas for improvement included: enhancing the diversity of program participants, program leaders and mentors across multiple sociodemographic domains; leveraging technology to strengthen the MFSP community of practice; and improving flexibility of the program.

The program evaluation results provide evidence supporting ongoing investment in faculty educators and summarizes key strengths and areas for improvement to inform future FD efforts for both the MFSP and other FD programs.
A case study of HIV/AIDS services from community-based organizations during COVID-19 lockdown in China
Authors: Bouey Jennifer Z.H. , Han Jing , Liu Yuxuan , Vuckovic Myriam , Zhu Keren , Zhou Kai , Su Ye
Published: March 2023

Introduction

People living with HIV (PLHIV) relied on community-based organizations (CBOs) in accessing HIV care and support during the COVID-19 pandemic in China. However, little is known about the impact of, and challenges faced by Chinese CBOs supporting PLHIV during lockdowns.

Methods

A survey and interview study was conducted among 29 CBOs serving PLHIV in China between November 10 and November 23, 2020. Participants were asked to complete a 20-minute online survey on their routine operations, organizational capacity building, service provided, and challenges during the pandemic. A focus group interview was conducted with CBOs after the survey to gather CBOs’ policy recommendations. Survey data analysis was conducted using STATA 17.0 while qualitative data was examined using thematic analysis.

Results

HIV-focused CBOs in China serve diverse clients including PLHIV, HIV high-risk groups, and the public. The scope of services provided is broad, ranging from HIV testing to peer support. All CBOs surveyed maintained their services during the pandemic, many by switching to online or hybrid mode. Many CBOs reported adding new clients and services, such as mailing medications. The top challenges faced by CBOs included service reduction due to staff shortage, lack of PPE for staff, and lack of operational funding during COVID-19 lockdowns in 2020. CBOs considered the ability to better network with other CBOs and other sectors (e.g., clinics, governments), a standard emergency response guideline, and ready strategies to help PLHIV build resilience to be critical for future emergency preparation.

Conclusion

Chinese CBOs serving vulnerable populations affected by HIV/AIDS are instrumental in building resilience in their communities during the COVID-19 pandemic, and they can play significant roles in providing uninterrupted services during emergencies by mobilizing resources, creating new services and operation methods, and utilizing existing networks. Chinese CBOs’ experiences, challenges, and their policy recommendations can inform policy makers on how to support future CBO capacity building to bridge service gaps during crises and reduce health inequalities in China and globally.
Golgi-apparatus genes related signature for predicting the progression-free interval of patients with papillary thyroid carcinoma
Authors: Liu Rui , Cao Zhen , Wu Mengwei , Li Xiaobin , Fan Peizhi , Liu Ziwen
Published: March 2023

Background

We aimed to build a novel model with golgi apparatus related genes (GaGs) signature and relevant clinical parameters for predicting progression-free interval (PFI) after surgery for papillary thyroid carcinoma (PTC).

Methods

We performed a bioinformatic analysis of integrated PTC datasets with the GaGs to identify differentially expressed GaGs (DE-GaGs). Then we generated PFI-related DE-GaGs and established a novel GaGs based signature. After that, we validated the signature on multiple external datasets and PTC cell lines. Further, we conducted uni- and multivariate analyses to identify independent prognostic characters. Finally, we established a signature and clinical parameters-based nomogram for predicting the PFI of PTC.

Results

We identified 260 DE-GaGs related to PFI in PTC. The functional enrichment analysis showed that the DE-MTGs were associated with an essential oncogenic glycoprotein biosynthetic process. Consequently, we established and optimized a novel 11 gene signature that could distinguish patients with poorer prognoses and predicted PFI accurately. The novel signature had a C-index of 0.78, and the relevant nomogram had a C-index of 0.79. Also, it was closely related to the pivotal clinical characters of and anaplastic potential in datasets and PTC cell lines. And the signature was confirmed a significant independent prognostic factor in PTC. Finally, we built a nomogram by including the signature and relevant clinical factors. Validation analysis showed that the nomogram’s efficacy was satisfying in predicting PTC’s PFI.

Conclusion

The GaGs signature and nomogram were closely associated with PTC prognosis and may help clinicians improve the individualized prediction of PFI, especially for high-risk patients after surgery.
Effects of spinal deformities on lung development in children: a review
Authors: Wang Yonggang , Wang Dongmin , Zhang Guangzhi , Ma Bing , Ma Yingping , Yang Yong , Xing Shuai , Kang Xuewen , Gao Bingren
Published: March 2023

Scoliosis before the age of 5 years is referred to as early-onset scoliosis (EOS). While causes may vary, EOS can potentially affect respiratory function and lung development as children grow. Moreover, scoliosis can lead to thoracic insufficiency syndrome when aggravated or left untreated. Therefore, spinal thoracic deformities often require intervention in early childhood, and solving these problems requires new methods that include the means for both deformity correction and growth maintenance. Therapeutic strategies for preserving the growing spine and thorax include growth rods, vertically expandable titanium artificial ribs, MAGEC rods, braces and casts. The goals of any growth-promoting surgical strategy are to alter the natural history of cardiorespiratory development, limit the progression of underlying spondylarthrosis deformities and minimize negative changes in spondylothorax biomechanics due to the instrumental action of the implant. This review further elucidates EOS in terms of its aetiology, pathogenesis, pathology and treatment.
The effect of music therapy on cognitive functions in patients with Alzheimer’s disease: a systematic review of randomized controlled trials
Authors: Bleibel Malak , El Cheikh Ali , Sadier Najwane Said , Abou-Abbas Linda
Published: March 2023

Background

The use of music interventions as a non-pharmacological therapy to improve cognitive and behavioral symptoms in Alzheimer’s disease (AD) patients has gained popularity in recent years, but the evidence for their effectiveness remains inconsistent.

Objectives

To summarize the evidence of the effect of music therapy (alone or in combination with pharmacological therapies) on cognitive functions in AD patients compared to those without the intervention.

Methods

A systematic literature search was performed in PubMed, Cochrane library, and HINARI for papers published from 1 January 2012 to 25 June 2022. All randomized controlled trials that compared music therapy with standard care or other non-musical intervention and evaluation of cognitive functions are included. Cognitive outcomes included: global cognition, memory, language, speed of information processing, verbal fluency, and attention. Quality assessment and narrative synthesis of the studies were performed.

Results

A total of 8 studies out of 144 met the inclusion criteria (689 participants, mean age range 60.47–87.1). Of the total studies, 4 were conducted in Europe (2 in France, 2 in Spain), 3 in Asia (2 in China, 1 in Japan), and 1 in the USA. Quality assessment of the retrieved studies revealed that 6 out of 8 studies were of high quality. The results showed that compared to different control groups, there is an improvement in cognitive functions after music therapy application. A greater effect was shown when patients are involved in the music making when using active music intervention (AMI).

Conclusion

The results of this review highlight the potential benefits of music therapy as a complementary treatment option for individuals with AD and the importance of continued investigation in this field. More research is needed to fully understand the effects of music therapy, to determine the optimal intervention strategy, and to assess the long-term effects of music therapy on cognitive functions.
Complement C3 mediates podocyte injury through TLR4/NFΚB-P65 signaling during ischemia–reperfusion acute kidney injury and post-injury fibrosis
Authors: Chen Yi , Lin Liyu , Rao Siyi , Tao Xuan , Cui Jiong , Wan Jianxin
Published: March 2023

Background

The aim of this study was to explore the mechanism of complement C3a mediating podocyte injury during ischemia–reperfusion acute kidney injury (IR-AKI) and post-injury fibrosis.

Methods

Renal artery clamping was used to establish IR-AKI and post-injury fibrosis model. HE and Masson staining were performed to observe renal fibrosis. The protein abundance levels were measured along with inflammatory markers, renal complement C3. Podocytes were treated with C3a with or without Toll-like receptor 4(TLR4) inhibitor. The effects of TLR4 up-regulation by TLR4 plasmids were examined.

Results

C3−/− resulted in amelioration of renal dysfunction by reducing podocyte damage and renal fibrosis. Immunoblot with renal tissue homogenates from IR-AKI mice revealed that C3−/− decreased TLR4/Nuclear Factor-κB (NFκB)-P65.

Conclusion

Our results indicate that modulating C3/TLR4/NFκB-P65 signaling pathway is a novel therapeutic target for the IR-AKI and post-injury fibrosis.

Graphical Abstract