Search Results (1,929)

Free-space optical (FSO) communications have emerged as a promising complement to conventional radio-frequency (RF) systems due to their high bandwidth, low interference, and license-free spectrum. Visible-light FSO communication, using laser diodes or LEDs, offers potential for short-range data links, but performance is highly wavelength-dependent under varying atmospheric conditions. This study presents an experimental evaluation of three visible laser diodes at 650 nm (red), 532 nm (green), and 405 nm (violet), focusing on their optical output power, quantum efficiency, and modulation behavior across a range of driving currents and frequencies. A custom laboratory testbed was developed using an Atmega328p microcontroller and a Visual Basic control interface, allowing precise control of current and modulation frequency. A silicon photovoltaic cell was employed as the optical receiver and energy harvester. The results demonstrate that the 650 nm red laser consistently delivers the highest quantum efficiency and optical output, with stable performance across electrical and modulation parameters. These findings support the selection of 650 nm as the most energy-efficient and versatile wavelength for short-range, cost-effective visible-light FSO communication. This work provides experimentally grounded insights to guide wavelength selection in the development of energy-efficient optical wireless systems. Full article

Fresh fruit are highly perishable commodities, facing significant postharvest losses primarily due to physiological deterioration and microbial spoilage. Conventional preservation methods often face limitations regarding safety, residue, and environmental impact. Because of its rapid decomposition and low-residue-impact characteristics, ozone has proven superior as an efficient and eco-friendly solution for preserving fruit quality after harvest. The maturation and aging processes of kiwifruit are closely linked to the involvement of reactive oxygen species (ROS) metabolism. This study aimed to investigate the effects of intermittent ozone treatment (21.4 mg/m³, applied for 0, 1, 3, or 5 h weekly) on ROS metabolism, the antioxidant defense system, and storage quality of kiwifruit during cold storage (0.0 ± 0.5 °C). The results showed ozone treatment slowed the decline in titratable acid (TA) content and fruit firmness, inhibited increases in total soluble solids (TSSs) and weight loss, and maintained the storage quality. Additionally, ozone treatment enhanced the activities of antioxidant-related enzymes. This includes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). Furthermore, it delayed the reduction in ascorbate (ASA), glutathione (GSH), total phenolic compounds, and flavonoid content, while also preventing the accumulation of ROS and the rise in malondialdehyde (MDA) levels. In summary, the results indicate that ozone treatment enhances the antioxidant capacity of kiwifruit by increasing the structural integrity of cell membranes, preserving the structural integrity of cell membranes, and effectively maintaining the storage quality of the fruit. Full article

This study aimed to investigate the efficacy of a composite coating composed of 150 mg/L ε-Poly-L-lysine (ε-PL) and 5 g/L chitosan (CTS) in extending the shelf life and maintaining the postharvest quality of fresh Tremella fuciformis. Freshly harvested T. fuciformis were treated by surface spraying, with distilled water serving as the control. The effects of the coating on storage quality, physicochemical properties, reactive oxygen species (ROS) metabolism, and membrane lipid metabolism were evaluated during storage at (25 ± 1) °C. The results showed that the ε-PL/CTS composite coating significantly retarded quality deterioration, as evidenced by reduced weight loss, maintained whiteness and color, and higher retention of soluble sugars, soluble solids, and soluble proteins. The coating also effectively limited water migration and loss. Mechanistically, the coated T. fuciformis exhibited enhanced antioxidant capacity, characterized by increased superoxide anion (O₂⁻) resistance capacity, higher activities of antioxidant enzymes (SOD, CAT, APX), and elevated levels of non-enzymatic antioxidants (AsA, GSH). This led to a significant reduction in malondialdehyde (MDA) accumulation, alongside improved DPPH radical scavenging activity and reducing power. Furthermore, the ε-PL/CTS coating preserved cell membrane integrity by inhibiting the activities of lipid-degrading enzymes (lipase, LOX, PLD), maintaining higher levels of key phospholipids (phosphatidylinositol and phosphatidylcholine), delaying phosphatidic acid accumulation, and consequently reducing cell membrane permeability. In conclusion, the ε-PL/CTS composite coating effectively extends the shelf life and maintains the quality of postharvest T. fuciformis by modulating ROS metabolism and preserving membrane lipid homeostasis. This study provides a theoretical basis and a practical approach for the quality control of fresh T. fuciformis. Full article

This study presents a compact and high-efficiency microstrip antenna integrated with a square electromagnetic band-gap (EBG) structure for radio frequency energy harvesting to power battery-less Internet of Things (IoT) sensors and medical devices in the 5.8 GHz Industrial, Scientific, and Medical (ISM) band. The proposed antenna features a compact design with reduced physical dimensions of 36 × 40 mm² (0.69λ_o × 0.76λ_o) while providing high-performance parameters such as a reflection coefficient of −27.9 dB, a voltage standing wave ratio (VSWR) of 1.08, a gain of 7.91 dBi, directivity of 8.1 dBi, a bandwidth of 188 MHz, and radiation efficiency of 95.5%. Incorporating EBG cells suppresses surface waves, enhances gain, and optimizes impedance matching through 50 Ω inset feeding. The simulated and measured results of the designed antenna show a high correlation. This study demonstrates a robust and promising solution for high-performance wireless systems requiring a compact size and energy-efficient operation. Full article

Continuous and accurate biomass measurement is a critical enabler for control, decision making, and optimization in modern plant production systems. It supports the development of plant growth models for advanced control strategies like model predictive control, and enables responsive, data-driven, and plant state-dependent cultivation. Traditional biomass measurement methods, such as destructive sampling, are time-consuming and unsuitable for high-frequency monitoring. In contrast, image-based estimation using computer vision and deep learning requires frequent retraining and is sensitive to changes in lighting or plant morphology. This work introduces a low-cost, load-cell-based biomass monitoring system tailored for vertical farming applications. The system operates at the level of individual growing trays, offering a valuable middle ground between impractical plant-level sensing and overly coarse rack-level measurements. Tray-level data allow localized control actions, such as adjusting light spectrum and intensity per tray, thereby enhancing the utility of controllable LED systems. This granularity supports layer-specific optimization and anomaly detection, which are not feasible with rack-level feedback. The biomass sensor is easily scalable and can be retrofitted, addressing common challenges such as mechanical noise and thermal drift. It offers a practical and robust solution for biomass monitoring in dynamic, growing environments, enabling finer control and smarter decision making in both commercial and research-oriented vertical farming systems. The developed sensor was tested and validated against manual harvest data, demonstrating high agreement with actual plant biomass and confirming its suitability for integration into vertical farming systems. Full article

A square patch metasurface is designed, simulated, fabricated, and experimentally tested to investigate polarization characteristics quantitatively. The metasurface consists of one layer unit cell in the form of a square patch with one via and a lumped resistor, which is used for harvesting RF (radio frequency) energy. FR4 dielectric is used as a substrate supported by a metal ground plane. Polarization-dependent properties with specific surface current patterns and voltage dip are obtained when simulating under normal incidence of a plane wave. This characteristic results from changes in surface current conditions when the polarization angle is varied. A voltage dip appears at a specific polarization angle when the surface current pattern is symmetrical. This condition occurs when the position of the lumped resistor from the center of the patch is perpendicular to the linearly polarized incident electric field. A couple of 10 × 10 arrays with different resistor positions are fabricated and tested. The experimental results are in good agreement with the simulated results. The proposed design demonstrates a symmetric unit cell structure with one via and a resistor that exhibits polarization-dependent behavior for linear polarization. An asymmetric patch design is explored through both simulation and measurement to mitigate polarization dependence by suppressing the dip behavior, albeit at the expense of reduced absorption efficiency. This study provides a complete polarization analysis for both symmetric and asymmetric patch metasurfaces with a single via and a single lumped resistor, and introduces a predictive relation between the position of the resistor relative to the center of the patch and the resulting voltage dip behavior. Full article

This Review examines up-to-date advancements in the integration of biomolecules and solar energy technologies, with a particular focus on biohybrid photovoltaic systems. Biomolecules have recently garnered increasing interest as functional components in a wide range of solar cell architectures, since they offer a huge variety of structural, optical, and electronic properties, useful to fulfill multiple roles within photovoltaic devices. These roles span from acting as light-harvesting sensitizers and charge transport mediators to serving as micro- and nanoscale structural scaffolds, rheological modifiers, and interfacial stabilizers. In this Review, a comprehensive overview of the state of the art about the integration of biomolecules across the various generations of photovoltaics is provided. The functional roles of pigments, DNA, proteins, and polysaccharides are critically reported improvements and limits associated with the use of biological molecules in optoelectronics. The molecular mechanisms underlying the interaction between biomolecules and semiconductors are also discussed as essential for a functional integration of biomolecules in solar cells. Finally, this Review shows the current state of the art, and the most significant results achieved in the use of biomolecules in solar cells, with the main scope of outlining some guidelines for future further developments in the field of biohybrid photovoltaics. Full article

This paper deals with a standard cell-based analog-in-concept pW-power building block as a comparator and a wake-up oscillator. Both topologies, traditionally conceived as an analog building block made by a custom process and supply voltage-dependent design flow, are designed only by using digital gates, enabling them to be automated and fully synthesizable. This further results in supply voltage scalability and regulator-less operation, allowing direct powering by an energy harvester without additional ancillary circuit blocks (such as current and voltage sources). In particular, the circuit similarities in implementing a rail-to-rail dynamic voltage comparator and a relaxation oscillator using only digital gates are discussed. The building blocks previously reported in the literature by the author will be described, and the common root of their design will be highlighted. Full article

Bird-dropping fouling and hotspot anomalies remain the most prevalent and detrimental defects in utility-scale photovoltaic (PV) plants; their co-occurrence on a single module markedly curbs energy yield and accelerates irreversible cell degradation. However, markedly disparate visual–thermal signatures of the two phenomena impede high-fidelity concurrent detection in existing robotic inspection systems, while stringent onboard compute budgets also preclude the adoption of bulky detectors. To resolve this accuracy–efficiency trade-off for dual-defect detection, we present YOLOv8-SG, a lightweight yet powerful framework engineered for mobile PV inspectors. First, a rigorously curated multi-modal dataset—RGB for stains and long-wave infrared for hotspots—is assembled to enforce robust cross-domain representation learning. Second, the HSV color space is leveraged to disentangle chromatic and luminance cues, thereby stabilizing appearance variations across sensors. Third, a single-head self-attention (SHSA) block is embedded in the backbone to harvest long-range dependencies at negligible parameter cost, while a global context (GC) module is grafted onto the detection head to amplify fine-grained semantic cues. Finally, an auxiliary bounding box refinement term is appended to the loss to hasten convergence and tighten localization. Extensive field experiments demonstrate that YOLOv8-SG attains 86.8% mAP@0.5, surpassing the vanilla YOLOv8 by 2.7 pp while trimming 12.6% of parameters (18.8 MB). Grad-CAM saliency maps corroborate that the model’s attention consistently coincides with defect regions, underscoring its interpretability. The proposed method, therefore, furnishes PV operators with a practical low-latency solution for concurrent bird-dropping and hotspot surveillance. Full article

Banana fruits are harvested and then undergo rapid ripening and senescence, sharply limiting their shelf-life and marketability. Myo-inositol (MI) is an important regulator in ethylene production and reactive oxygen species (ROS) accumulation; however, its involvement in the postharvest ripening process of banana remains to be determined. This study found that postharvest application of MI could efficiently delay the fruit ripening and extend the time in which the luster, color, and hardness were maintained in two cultivars with contrasting storage characteristics, storable ‘Brazil’ and unstorable ‘Fenza No. 1’, when stored at room temperature (23 °C ± 2 °C). Moreover, physiological, metabolic, and gene expression analyses indicated that MI application improved MI metabolism and postponed ethylene biosynthesis and cell wall loosening. The decrease in ethylene production was associated with a reduction in the expression of ACS1 and ACO1 genes. MI treatment decreased the expressions of PL1/2, PG, and EXP1/7/8, which may account for the delay in softening. In addition, the application of MI could alleviate ROS-mediated senescence and cell membrane damage by promoting the activities of SOD, POD, and anti-O₂⁻ and decreasing PPO activity. This study shed light on the function of MI in regulating the postharvest ripening and senescence of bananas and provided an efficient strategy for extending shelf-life and reduce losses. Full article

Microalgae proteins are increasingly recognized in the food and nutraceutical industries for their functional versatility and high nutritional value. Mild alkaline treatment is commonly used for cell wall degradation and intracellular protein solubilization, consequently enhancing the protein extraction yield. The findings of this study reveal that alkaline treatment alone, even at higher NaOH concentration (up to 0.3 M) and treatment time (up to 90 min), was ineffective (max. 2.4% yield) for the extraction of protein from Auxenochlorella protothecoides biomass. This challenge was significantly reduced through synergistic application of mechanical cell disruption using high-pressure homogenization (HPH) and alkaline solubilization. Single-pass HPH (35 k psi) alone without alkaline treatment led to 52.3% protein solubilization from wet biomass directly harvested from culture broth, while it was only 18.5% for spray-dried biomass. The combined effect of HPH and alkaline (0.1 M NaOH) treatment significantly increased protein extraction yield to 68.0% for a spray-dried biomass loading of 50 g L⁻¹. Through replacing spray-dried biomass with wet biomass, the requirement of NaOH was reduced by 5-fold to 0.02 M to achieve a similar yield of 68.1%. The process integration of HPH with the mild alkaline solubilization and utilization of wet biomass from culture broth showed high potential for industrialization of microalgae protein extraction. This method achieves high extraction yield while reducing alkaline waste and eliminating the need for energy-consuming drying of biomass, thereby minimizing the environmental impact. Full article

Background: It is estimated that in Italy, there were 364,000 new diagnoses of neoplasms each year and that the overall incidence of blood cancers was 10% of these. Leukemia and lymphomas represented the ninth and eighth places, respectively, among the causes of death from neoplasia. Hematopoietic stem cell transplantation represented an effective treatment option for many of these malignancies, and not only that: benign and congenital diseases could also be treated. Objective: To assess knowledge among the Apulian population regarding stem cell donation and factors that could influence this choice, focusing especially on the knowledge of the residents of Puglia, Italy on how stem cells were harvested and their functions, their reasons for joining the National Registry, and the reasons that hold them back from making such a choice. Study Design: An observational and cross-sectional study was conducted, through snowball sampling methodology, until data saturation. An online survey was conducted, which included several Italian associations. The questionnaire administered contained five main sections, such as sociodemographic data, knowledge of the existence of National Registries and their adherence, the nationwide presence of various associations that promote donation, knowledge with respect to the structure, use and functions of stem cells, sources of procurement, such as bone marrow, peripheral blood and umbilical cord, and related procedures, beliefs, attitudes, values, and opinions of the Italian population regarding the topic, and degree of information and education regarding bone marrow donation. Results: A total of 567 Apulian citizens were enrolled. Of these, 75.3% were female and 96.8% were aged between 18 and 65 years. Most of participants were single (46.9%) and married (47.3%) and had a diploma (44.4%), and less had a degree (35.8%). Significant differences were recorded between gender, singles, and married participants, and participants with a diploma or a degree and the items proposed. Conclusions: A true culture of donation in our region was not clearly spread. Although something has been accomplished in recent years in terms of deceased donor donation, still a great deal needs to be achieved for living donation, which encountered a great deal of resistance. It has been deemed necessary to seek winning solutions to this issue in terms of communication and information campaigns, raising awareness and empowering citizens to express consciously their concerns about organs and tissues and to stand in solidarity with those who suffered. Full article

Deposition of intramuscular fat (IM), also known as marbling, is the deciding factor of beef quality grade in the U.S. Defining molecular mechanisms underlying the differential deposition of adipose tissue in distinct anatomical areas in beef cattle is key to the development of strategies for marbling enhancement while limiting the accumulation of excessive subcutaneous adipose tissue (SAT). The objective of this exploratory study was to define the IM and SAT transcriptional heterogeneity at the whole tissue and single-nuclei levels in beef steers. Longissimus dorsi muscle samples (9–11th rib) were collected from two finished beef steers at harvest to dissect matched IM and adjacent SAT (backfat). Total RNA from IM and SAT was isolated and sequenced in an Illumina NovaSeq 6000. Nuclei from the same samples were isolated by dounce homogenization, libraries generated with 10× Genomics, and sequenced in an Illumina NovaSeq 6000, followed by analysis via Cell Ranger pipeline and Seurat in RStudio (v4.3.2) By the expression of signature marker genes, single-nuclei RNA sequencing (snRNAseq) analysis identified mature adipocytes (AD; ADIPOQ, LEP), adipose stromal and progenitor cells (ASPC; PDGFRA), endothelial cells (EC; VWF, PECAM1), smooth muscle cells (SMC; NOTCH3, MYL9) and immune cells (IMC; CD163, MRC1). We detected six cell clusters in SAT and nine in IM. Across IM and SAT, AD was the most abundant cell type, followed by ASPC, SMC, and IMC. In SAT, AD made up 50% of the cellular population, followed by ASPC (31%), EC (14%), IMC (1%), and SMC (4%). In IM depot, AD made up 23% of the cellular population, followed by ASPC at 19% of the population, EC at 28%, IMC at 7% and SMC at 12%. The abundance of ASPC and AD was lower in IM vs. SAT, while IMC was increased, suggesting a potential involvement of immune cells on IM deposition. Accordingly, both bulk RNAseq and snRNAseq analyses identified activated pathways of inflammation and metabolic function in IM. These results demonstrate distinct transcriptional cellular heterogeneity between SAT and IM depots in beef steers, which may underly the mechanisms by which fat deposits in each depot. The identification of depot-specific cell populations in IM and SAT via snRNAseq analysis has the potential to reveal target genes for the modulation of fat deposition in beef cattle. Full article

Background: The spleen is the primary reservoir of immune cells in mammals. Diverse stimuli can disrupt spleen homeostasis, resulting in spleen injury and immune dysfunction. This study employed a porcine model to assess the therapeutic potential of salvianolic acid B (SAB) against lipopolysaccharide (LPS)-induced splenic injury. Methods: Seventy-two male weanling piglets were randomly assigned to one of four groups: CON-SS, SAB-SS, CON-LPS, and SAB-LPS. The CON-SS and CON-LPS groups received a basal diet, while SAB-SS and SAB-LPS groups received a SAB-supplemented diet. After 14 d, the CON-SS and SAB-SS groups received an intraperitoneal injection of sterile saline, whereas the CON-LPS and SAB-LPS groups were injected with LPS. Blood and spleen tissues were harvested 6 h post-injection for biochemical analysis. Results: LPS induced systemic immune disorders in piglets, as evidenced by increased immune organ indices and decreased white blood cell, lymphocyte, and basophil counts in blood (p < 0.05). LPS also caused histoarchitectural disruption, cell apoptosis, oxidative stress, and inflammation in the spleen (p < 0.05). Conversely, SAB improved splenic histopathology and reduced splenic apoptosis and pro-inflammatory mediators in piglets (p < 0.05). SAB significantly mitigated peroxidation accumulation by facilitating the nuclear translocation of nuclear factor erythroid 2-related factor 2 and strengthening the antioxidant system, and inhibited nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome activation (p < 0.05). Mechanistically, SAB attenuated LPS-induced splenic oxidative stress and NLRP3 inflammasome activation by restoring mitochondrial structure and function (p < 0.05). Conclusions: This research unveils that SAB alleviates LPS-induced spleen disorder by reinforcing antioxidant system and suppressing NLRP3 inflammasome, highlighting SAB’s potential as a prospective therapeutic agent for spleen disorders. Full article

Umbilical cord mesenchymal stem cells (UCMSCs)-derived small extracellular vehicles (sEVs) are reported to offer therapeutic effects in regenerative medicine, but they lack safety and biodistribution profiles to support smooth translation at the clinical stage and regulatory requirements. Our study aimed to determine the safety and biodistribution profile in a healthy animal model before application in the metabolic syndrome model. Method: Healthy male Sprague Dawley (SD) rats were given an intravenous (IV) injection of normal saline (control group) or pooled fetal UCMSCs-derived sEVs (treated group) every three weeks for 90 days. Morbidity and mortality observation (daily), physical measurements (weekly), selected serum biochemistry (every three weeks), and hematology (every three weeks) were performed for 90 days. Acute toxicity (on day 14) and sub-chronic toxicity (on day 90) were assessed for gross necropsy, relative organ weight, and histopathological assessment of lungs, liver, spleen, kidney, and lymph nodes. Separately, a biodistribution study was conducted with the sEVs preparations labeled with PKH26 fluorescent dye, given intravenously to the rats. The organs were harvested 24 h post-injection. There were no drastic changes in either group’s morbidity or mortality, physical, hematological, and biochemistry evaluation. The histopathological assessment concluded moderate (focal) inflammation in the treated group’s kidneys and signs of recovery from the inflammation and vascular congestion in the liver. A biodistribution study revealed a higher accumulation of sEVs in the spleen. Multiple IV injections of the pooled fetal UCMSCs-derived sEVs in healthy male SD rats were deemed safe. The sEVs were abundantly distributed in the spleen 24 h post-injection. Full article