Search Results (153)

Platelet-rich plasma (PRP) has become an increasingly valuable biologic approach for personalized regenerative medicine because of its potent anti-inflammatory/healing effects. It is thought to be an excellent source of growth factors that can promote tissue healing and lessen fibrosis. Although this treatment has demonstrated effectiveness in numerous disease areas, its impact on pulmonary fibrosis (PF) caused by silver nanoparticles (AgNPs) via its antiapoptotic effects remains to be explored. AgNPs were synthesized biologically by Bacillus megaterium ATCC 55000. AgNP characterization was carried out via UV–Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) imaging to reveal monodispersed spheres with a mean diameter of 45.17 nm. A total of 48 male Wistar rats divided into six groups, with 8 rats per group, were used in the current study on the basis of sample size and power. The groups used were the PRP donor, control, AgNP, AgNP + PRP, AgNP + dexamethasone (Dexa) rat groups, and a recovery group. Body weights, hydroxyproline (HP) levels, and CASP3 and TWIST1 gene expression levels were assessed. H&E and Sirius Red staining were performed. Immunohistochemical studies for inducible nitric oxide synthase (iNOS) and cluster of differentiation 68 (CD68) with histomorphometry were conducted. A significant reduction in body weight (BWt) was noted in the AgNP group compared with the AgNP + PRP group (p < 0.001). HP, CASP3, and TWIST1 expression levels were significantly increased by AgNPs but decreased upon PRP (p < 0.001) treatment. Compared with those in the control group, the adverse effects of AgNPs included PF, lung alveolar collapse, thickening of the interalveolar septa, widespread lymphocytic infiltration, increased alveolar macrophage CD68 expression, and iNOS positivity in the cells lining the alveoli. This work revealed that PRP treatment markedly improved the histopathological and immunohistochemical findings observed in the AgNP group in a manner comparable to that of the Dexa. In conclusion, these results demonstrated the therapeutic potential of PRP in a PF rat model induced via AgNPs. This study revealed that PRP treatment significantly improved the histopathological and immunohistochemical alterations observed in the AgNP-induced group, with effects comparable to those of the Dexa. In conclusion, these findings highlight the therapeutic potential of PRP in a rat model of AgNP-induced PF. Full article

Background: PSMA PET/CT imaging has become a cornerstone in the management of prostate cancer, particularly in the setting of biochemical recurrence (BCR). While semi-quantitative parameters such as SUVmean have been evaluated as prognostic biomarkers in metastatic castration-resistant prostate cancer (mCRPC), particularly after the VISION trial, the prognostic role of volumetric measures such as Total Molecular Volume (TMV) remain largely unexplored, especially in earlier stages of the disease such as in biochemical recurrence following primary treatment. Methods: This retrospective monocentric study included 84 patients with BCR who underwent PSMA PET/CT imaging between 2020 and 2021 using either [⁶⁸Ga]Ga-PSMA-11(Ga-PSMA) or [¹⁸F]-PSMA-1007 (F-PSMA) as tracers. Total tumor burden was assessed through manual 3D segmentation to derive whole-body Total Molecular Volume (wb TMV) and Total Lesion PSMA (wb TL-PSMA). Clinical and imaging variables were correlated with overall survival (OS) and progression-free survival (PFS) using Cox regression models. Kaplan–Meier analyses were performed based on wb TMV and thresholds determined by the Youden index. Results: A PSMA PET/CT correlation for BCR was identified in 69% of patients, with comparable detection rates between tracers (Ga-PSMA 67% vs. F-PSMA 63%, p = 0.7). A higher wb TMV was significantly associated with worse OS (HR 2.20, p < 0.001) and PFS (HR 2.01, p < 0.001) in univariable analyses. In multivariable models, log₂(wb TMV) remained an independent prognostic factor for PFS (HR 1.78, p = 0.005). Patients with log₂(wb TMV) > 2.87 exhibited significantly poorer survival outcomes. A PSA at diagnosis > 17 ng/mL also predicted shorter PFS. Conclusions: Tumor segmentation from PSMA PET/CT imaging provides powerful prognostic information in patients with biochemical recurrence of prostate cancer, independently of the tracer used. The wb TMV represents a promising volumetric biomarker for future risk stratification and therapeutic decision-making, particularly in earlier stages of prostate cancer progression, where predictive imaging biomarkers remain largely undefined. Full article

Background and Objectives: Despite developments in cervical cancer (CC) treatment, an advanced stage is a poor prognostic factor. Cervical cancer is an immunogenic tumor in which viruses, like HPV, play a role in carcinogenesis. Therefore, systemic inflammatory markers (SIMs) may have prognostic value. Most studies on SIMs focus on the early stage by evaluating pretreatment levels. This study aims to evaluate the prognostic and predictive values of both pretreatment and post-treatment parameters at the advanced stage, as well as treatment efficacy after progression with first-line treatment. Materials and Methods: A total of 133 advanced-stage CC patients with progression on first-line platin–paclitaxel and bevacizumab were evaluated retrospectively. Demographic and histopathological characteristics were recorded along with treatment details. Pre-treatment baseline blood parameters and post-treatment follow-up values were recorded to calculate SIMs as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammatory response index (SIRI). Results: Median values for SIMs were accepted as cut-off values. Post-treatment values demonstrated stronger predictive power, with pre-treatment SIRI and NLR being significant only in univariate analysis, but not in multivariate analysis. High post-treatment SIRI (>2.1) was correlated with shorter overall survival (OS) and considered a poor prognostic factor. High post-treatment SIRI (>2.1), -SII (>746), and -PLR (>197) emerged as independent prognostic factors for progression-free survival (PFS). Their prognostic values were clearer in the whole population and the metachronous metastatic subgroup. Rechallenge of platinum-based chemotherapy was an option for those who had at least 6 months of PFS with first-line platinum-based chemotherapy. Bevacizumab addition to single-agent or combination regimens led to improved ORR as well. Conclusions: Post-treatment SIRI is a promising prognostic factor for OS, while post-treatment SIRI, SII, and PLR may serve as convenient SIMs for PFS. Platinum-based combination chemotherapy reinduction is a feasible second-line treatment strategy, especially with the addition of bevacizumab. Full article

In this study, borophene and nickel phthalocyanine (NiPc): borophene nanocomposites were prepared using the sonication method. The NiPc: borophene nanocomposite was uniformly obtained as a 10–80 nm-sized spherically shaped particle. Electrical conductivities (s) were measured as 3 × 10⁻¹³ Scm⁻¹ and 9.5 × 10⁻⁹ Scm⁻¹ for NiPc and the NiPc: borophene nanocomposite, respectively. The SEM image showed that borophene was homogeneously distributed in the NiPc matrix and increased the charge transport pathways. This is the main reason for a 10⁶-fold increase in electrical conductivity. An indium tin oxide (ITO)/NiPc: borophene nanocomposite-based thermoelectric generator (TEG) was prepared and characterized. The Seebeck coefficients (S) were calculated to be 5 μVK⁻¹ and 30 μVK⁻¹ for NiPc and the NiPc: borophene nanocomposite, respectively. A positive Seebeck coefficient value for the NiPc: borophene showed the p-type nature of the nanocomposite. The power factors (PF = sS2) were calculated as 7.5 × 10⁻¹⁶ μW m⁻¹ K⁻² and 8.6 × 10⁻¹⁰ μW m⁻¹ K⁻² for NiPc and the NiPc: borophene nanocomposite, respectively. Compositing NiPc with borophene increased the power factor by ~10⁶-fold. It has been concluded that the electrical conductivity and Seebeck coefficient of the NiPc: borophene material increases due to energy band convergence because of combining p-type NiPc with p-type borophene. Therefore, the NiPc: borophene nanocomposite is a promising material for TEG. Full article

Distributed generation (DG) within the electrical distribution network (DN) has witnessed significant expansion globally, attributed to both technological advancements and environmental benefits. However, uncoordinated integration of DG in suboptimal locations can negatively influence the operational efficacy through issues such as increased power losses, voltage fluctuations, and protection coordination issues of the DN. Consequently, the optimal allocation of DG represents a critical element of consideration. Furthermore, the integration of network reconfiguration (NR) alongside DG units has the potential to significantly enhance system performance with only the existing infrastructure. Therefore, this work focuses on improving DN performance with optimal DG integration along with NR. The considered objectives are minimization of active power loss (APL) and cost of annual energy loss (CAEL). CAEL minimization by DG allocation and NR under multiple load models is addressed for the first time in this study. The efficacy of the employed hiking optimization algorithm (HOA) is illustrated through its application to the IEEE 33-Bus DN under various scenarios of DG operational power factors (PFs). A comparative analysis between the HOA and other reported methodologies is presented. Additionally, the results obtained for CAEL in case 6 (DG allocation with NR) are approximately 22.3% better that the best reported results of CAEL without NR, thereby affirming the usefulness of integrating the NR during DG allocation. Full article

For modern power plants to be dependable, safe, sustainable, and provide the highest operational efficiency (i.e., enhance dynamic load distribution with a faster response time at reduced reactive losses), there must be an intelligent dynamic load management system based on modern computational techniques to prevent overloading of power devices (i.e., alternators, transformers, etc.) in grid systems. In this paper, a co-simulation framework (Panda-SDN Load Balancer) is designed to achieve maximum operational efficiency from the power grid with the prime objective of real-time intelligent load balancing of operational power devices (i.e., power transformers, etc.). This framework is based on the integration of two tools: (a) PandaPower (an open-source Python tool) used for real-time power data (voltage; current; real power, P_Real; apparent power, P_Apparent; reactive power, P_Reactive; power factor, PF; etc.) load flow analysis; (b) Mininet used for the designing of a Software-Defined Network (SDN) with a POX controller for managing the load patterns on power transformers after load flow analysis obtained through PandaPower via the synchronization tool Message Queuing Telemetry Transport (MQTT) and Intelligent Electrical Devices (IEDs). In this research article, the simulation is performed in three scenarios: (a) normal flow, (b) loaded flow without the proposed framework, and (c) loaded flow with the proposed framework. As per simulation results, the proposed framework offered intelligent substation automation with (a) balanced utilization of a transformer, (b) enhanced system power factor in extreme load conditions, and (c) significant gain in system operational efficiency as compared to legacy load management methods. Full article

Voltage-controlled AC to DC converters govern the load voltage as per requirement. They may be employed in numerous applications, including battery-charging systems, light dimming, and industrial speed drive systems. The voltage regulation is based on the delay angle control of the thyristors, which has a simple gate control mechanism. Still, their input currents are highly distorted due to the generation of low-order harmonics. Also, their output voltage can only be regulated in step-down mode. The total harmonic distortion (THD) of the input current depends on the relative value of the fundamental frequency components to their non-fundamental component. The power factor (PF) also depends on these values, as well as the phase displacement angle, which is controlled by the firing delay. The improvement in THD and PF can be enhanced by maintaining the sinusoidal characteristics of the input current as much as possible. The use of an AC filter may enhance these characteristics, but filtering the low-order harmonics is a big challenge. This research suggests a novel control and circuit of a single-phase rectifier that may ensure the sinusoidal characteristics of the input current with a dual polarity-controlled output voltage. Thus, it improves the THD and PF for any polarity of the output DC voltage. A practical test circuit is built for the validation of the analytical and computer simulation results. Full article

Validating measures of psychological flexibility (PF) and psychological inflexibility (PI) has occurred in multiple adult samples, but little research has validated PF and PI measures with adolescents. This manuscript describes two studies exploring the validity of responses to the Multidimensional Psychological Flexibility Inventory (MPFI) with two samples of adolescents. The first study used exploratory factor analyses on responses to the MPFI with a sample of 16–17-year-olds (N = 249). The results yielded a reduced and simplified measurement model that consisted of two general factors: one for PF and the other for PI. These exploratory findings were further investigated with confirmatory factor analyses in the second study, with a larger sample of 14–17-year-olds (N = 503). The results from the second study generally confirmed the factor model from the first study. Findings from both studies showed that scores derived from the reduced MPFI measurement model evidenced convergent and divergent validity with a variety of mental health criterion measures. Moreover, findings from the second study showed that PF and PI scores had differential predictive power on different concurrent mental health outcomes. This discussion highlights the implications of measuring PF and PI in adolescents, considers limitations of the present studies, and recommends next steps for research. Full article

The Cuk power factor correction (PFC) converter with an input inductor operating discontinuous conduction mode (DCM) is widely utilized for its advantages of continuous input and output currents, low output voltage ripple, and simple control. However, the conventional Cuk PFC converter encounters issues such as the inability to achieve high power factor (PF) because of input current distortion and high intermediate capacitor voltage, especially at high input voltage. To achieve high PF, high efficiency, and low intermediate capacitor voltage simultaneously, by operating the output inductor at critical conduction mode (CRM) and adjusting input inductance from 170 µH to 930 µH within the half-line cycle dynamically with the transient rectified input voltage, a DCM-CRM Cuk PFC converter utilizing variable inductor control is proposed in this paper. The topology operational principle, control strategy, and key characteristics of the proposed converter have been studied. A 108 W experimental prototype was built and tested to validate the proposed converter. According to the comparative experimental results between the conventional converter and the proposed converter, it can be concluded that the proposed converter utilizing variable inductor control can enhance the PF and efficiency and reduce the intermediate capacitor voltage and total harmonic distortion (THD) of input current with universal 90~240 Vac input voltage range. Full article

This paper examines the current state of Home Energy Management Systems (HEMSs), highlighting the key role of the single-phase bidirectional rectifier (SPBR). It provides a detailed design process for the converter used in HEMSs, with a particular focus on the bidirectional charge and discharge of high-voltage batteries. The converter’s operating conditions were determined through a comprehensive evaluation of its components, which were designed and assessed to enable accurate power loss calculations. This approach ensures proper component sizing and a clear understanding of the converter’s efficiency. A specialized electronic control circuit manages two operating modes of the converter: a boost rectifier with power factor correction (PFC) and a sinusoidal pulse width modulation (SPWM) inverter. To validate the design, a 7.4 kW prototype was developed using silicon carbide (SiC) metal oxide semiconductor field effect transistors (MOSFETs). The prototype achieved a peak efficiency of nearly 98% in both modes, with a unity power factor (PF) and total harmonic distortion (THD) below 7% at full power. Full article

In this study, the design of output low-pass capacitive–inductive (CL) filters is analyzed and optimized for current-source single-phase grid-connected photovoltaic (PV) inverters. Four different CL filter configurations with varying damping resistor placements are examined, evaluating performance concerning the output current’s total harmonic distortion (THD), the power factor (PF), and power losses. High-frequency harmonics are effectively attenuated by a second-order CL filter with the damping resistor placed parallel to the filter inductor. In addition, this filter type achieves the best performance by minimizing power loss. A systematic design methodology using filter normalization techniques allows to determine the optimum filter parameters based on the specified cut-off frequency (500 Hz), power loss (5% of rated power), and target THD (<5%). The analysis, simulations, and experiments show that under various operating conditions, this approach meets the grid connection standards (current THD < 5%, power factor between 0.8 leading and 0.95 lagging) while improving efficiency. Full article

Providing self-powered energy for wearable electronic devices is currently an important research direction in the field of thermoelectric (TE) thin films. In this study, a simple dual-source magnetron sputtering method was used to prepare Ag₂Te thin films, which exhibit good TE properties at room temperature, and the growth temperature and subsequent annealing process were optimized to obtain high-quality films. The experimental results show that films grown at a substrate temperature of 280 °C exhibit a high power factor (PF) of ~3.95 μW/cm·K² at room temperature, which is further improved to 4.79 μW/cm·K² after optimal annealing treatment, and a highest PF of ~7.85 μW/cm·K² was observed at 200 °C. Appropriate annealing temperature effectively increases the carrier mobility of the Ag₂Te films and adjusts the Ag/Te ratio to make the composition closer to the stoichiometric ratio, thus promoting the enhancement of electrical transport properties. A TE device with five legs was assembled using as-fabricated Ag₂Te thin films. With a temperature difference of 40 K, the device was able to generate an output voltage of approximately 14.43 mV and a corresponding power of about 50.52 nW. This work not only prepared a high-performance Ag₂Te film but also demonstrated its application prospects in the field of self-powered electronic devices. Full article

To address the challenges of low accuracy in indoor positioning caused by factors such as signal interference and visual distortions, this paper proposes a novel method that integrates ultra-wideband (UWB) technology with visual positioning. In the UWB positioning module, the powerful feature-extraction ability of the graph convolutional network (GCN) is used to integrate the features of adjacent positioning points and improve positioning accuracy. In the visual positioning module, the residual results learned from the bidirectional gate recurrent unit (Bi-GRU) network are compensated into the mathematical visual positioning model’s solution results to improve the positioning results’ continuity. Finally, the two positioning coordinates are fused based on particle filter (PF) to obtain the final positioning results and improve the accuracy. The experimental results show that the positioning accuracy of the proposed UWB positioning method based on a GCN is less than 0.72 m in a single UWB positioning, and the positioning accuracy is improved by 55% compared with the Chan–Taylor algorithm. The proposed visual positioning method based on Bi-GRU and residual fitting has a positioning accuracy of 0.42 m, 71% higher than the Zhang Zhengyou visual positioning algorithm. In the fusion experiment, 80% of the positioning accuracy is within 0.24 m, and the maximum error is 0.66 m. Compared with the single UWB and visual positioning, the positioning accuracy is improved by 56% and 52%, respectively, effectively enhancing indoor pedestrian positioning accuracy. Full article

In this paper, a three-phase single-stage AC-DC converter for an IPT-based small wind power generation system (WPGS) with an S-S compensation circuit is proposed. It applies a three-phase single-stage AC-DC converter to improve the input power factor (PF), efficiency, and reliability in small WPGSs. Also, inductive power transfer (IPT) was applied to compensate for brush wear in the nacelle of small and medium-sized wind turbines while ensuring electrical safety. In conditions of the three-phase Permanent Magnet Synchronous Generator (PMSG) voltage (80~260 V_rms) for the wind turbine and the load (150~1000 W), it was verified that the desired output voltage below 3% can be controlled through the fixed link voltage (V_Link) control without wireless communication. A 1 kW prototype was built and tested to demonstrate its applicability to the rotation of small and medium-sized wind turbine nacelles instead of brushes and slip rings. Full article

In the development of wearable electronic devices, the composite modification of conductive polymers and single-walled carbon nanotubes (SWCNTs) has become a burgeoning research area. This study presents the synthesis of a novel polythiophene derivative, poly(3-alkoxythiophene) (P3(TEG)T), with alkoxy side chains. Different molecular weight variants of P3(TEG)T (P1–P4) were prepared and combined with SWCNTs to form composite materials. Density functional theory (DFT) calculations revealed a reduced bandgap for P3(TEG)T. Raman spectroscopy demonstrated π-π interactions between P3(TEG)T and SWCNTs, facilitating the dispersion of single-walled carbon nanotubes and the formation of a continuous conductive network. Among the composite films, P4/SWCNTs-0.9 exhibited the highest thermoelectric performance, with a power factor (PF) value of 449.50 μW m⁻¹ K⁻². The fabricated flexible thermoelectric device achieved an output power of 3976.92 nW at 50 K, with a tensile strength of 59.34 MPa for P4/SWCNTs. Our findings highlight the strong interfacial interactions between P3(TEG)T and SWCNTs in the composite material, providing an effective charge transfer pathway. Furthermore, an improvement in the tensile performance was observed with an increase in the molecular weight of the polymer used in the composite, offering a viable platform for the development of high-performance flexible organic thermoelectric materials. Full article