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Keywords = photo consistency

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20 pages, 2618 KiB  
Article
Advanced Oxidation of Dexamethasone by Activated Peroxo Compounds in Water Matrices: A Comparative Study
by Liina Onga, Niina Dulova and Eneliis Kattel-Salusoo
Water 2025, 17(15), 2303; https://doi.org/10.3390/w17152303 - 3 Aug 2025
Viewed by 339
Abstract
The continuous occurrence of steroidal pharmaceutical dexamethasone (DXM) in aqueous environments indicates the need for an efficient removal technology. The frequent detection of DXM in surface water could be substantially reduced by the application of photo-induced advanced oxidation technology. In the present study, [...] Read more.
The continuous occurrence of steroidal pharmaceutical dexamethasone (DXM) in aqueous environments indicates the need for an efficient removal technology. The frequent detection of DXM in surface water could be substantially reduced by the application of photo-induced advanced oxidation technology. In the present study, Fe2+ and UVA-light activated peroxo compounds were applied for the degradation and mineralization of a glucocorticoid, 25.5 µM DXM, in ultrapure water (UPW). The treatment efficacies were validated in real spring water (SW). A 120 min target pollutant degradation followed pseudo first-order reaction kinetics when an oxidant/Fe2+ dose 10/1 or/and UVA irradiation were applied. Acidic conditions (a pH of 3) were found to be more favorable for DXM oxidation (≥99%) regardless of the activated peroxo compound. Full conversion of DXM was not achieved, as the maximum TOC removal reached 70% in UPW by the UVA/H2O2/Fe2+ system (molar ratio of 10/1) at a pH of 3. The higher efficacy of peroxymonosulfate-based oxidation in SW could be induced by chlorine, bicarbonate, and carbonate ions; however, it is not applicable for peroxydisulfate and hydrogen peroxide. Overall, consistently higher efficacies for HO-dominated oxidation systems were observed. The findings from the current paper could complement the knowledge of oxidative removal of low-level DXM in real water matrices. Full article
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16 pages, 5703 KiB  
Article
Document Image Shadow Removal Based on Illumination Correction Method
by Depeng Gao, Wenjie Liu, Shuxi Chen, Jianlin Qiu, Xiangxiang Mei and Bingshu Wang
Algorithms 2025, 18(8), 468; https://doi.org/10.3390/a18080468 - 26 Jul 2025
Viewed by 300
Abstract
Due to diverse lighting conditions and photo environments, shadows are almost ubiquitous in images, especially document images captured with mobile devices. Shadows not only seriously affect the visual quality and readability of a document but also significantly hinder image processing. Although shadow removal [...] Read more.
Due to diverse lighting conditions and photo environments, shadows are almost ubiquitous in images, especially document images captured with mobile devices. Shadows not only seriously affect the visual quality and readability of a document but also significantly hinder image processing. Although shadow removal research has achieved good results in natural scenes, specific studies on document images are lacking. To effectively remove shadows in document images, the dark illumination correction network is proposed, which mainly consists of two modules: shadow detection and illumination correction. First, a simplified shadow-corrected attention block is designed to combine spatial and channel attention, which is used to extract the features, detect the shadow mask, and correct the illumination. Then, the shadow detection block detects shadow intensity and outputs a soft shadow mask to determine the probability of each pixel belonging to shadow. Lastly, the illumination correction block corrects dark illumination with a soft shadow mask and outputs a shadow-free document image. Our experiments on five datasets show that the proposed method achieved state-of-the-art results, proving the effectiveness of illumination correction. Full article
(This article belongs to the Section Combinatorial Optimization, Graph, and Network Algorithms)
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22 pages, 1835 KiB  
Article
Homogeneous and Heterogeneous Photo-Fenton-Based Photocatalytic Techniques for the Degradation of Nile Blue Dye
by Georgia Papadopoulou, Eleni Evgenidou and Dimitra Lambropoulou
Appl. Sci. 2025, 15(14), 7917; https://doi.org/10.3390/app15147917 - 16 Jul 2025
Viewed by 352
Abstract
In this study, the degradation of Nile Blue dye was investigated using homogeneous and heterogeneous photocatalytic methods based on the photo-Fenton reaction. More specifically, for homogeneous photocatalysis, the classical photo-Fenton (UV/Fe2+/H2O2) and modified photo-Fenton-like (UV/Fe2+/S [...] Read more.
In this study, the degradation of Nile Blue dye was investigated using homogeneous and heterogeneous photocatalytic methods based on the photo-Fenton reaction. More specifically, for homogeneous photocatalysis, the classical photo-Fenton (UV/Fe2+/H2O2) and modified photo-Fenton-like (UV/Fe2+/S2O82−) systems were studied, while for heterogeneous photocatalysis, a commercial MOF catalyst, Basolite F300, and a natural ferrous mineral, geothite, were employed. Various parameters—including the concentrations of the oxidant and catalyst, UV radiation, and pH—were investigated to determine their influence on the reaction rate. In homogeneous systems, an increase in iron concentration led to an enhanced degradation rate of the target compound. Similarly, increasing the oxidant concentration accelerated the reaction rate up to an optimal level, beyond which radical scavenging effects were observed, reducing the overall efficiency. In contrast, heterogeneous systems exhibited negligible degradation in the absence of an oxidant; however, the addition of oxidants significantly improved the process efficiency. Among the tested processes, homogeneous techniques demonstrated a superior efficiency, with the conventional photo-Fenton process achieving complete mineralization within three hours. Kinetic analysis revealed pseudo-first-order behavior, with rate constants ranging from 0.012 to 0.688 min−1 and correlation coefficients (R2) consistently above 0.90, confirming the reliability of the applied model under various experimental conditions. Nevertheless, heterogeneous techniques, despite their lower degradation rates, also achieved high removal efficiencies while offering the advantage of operating at a neutral pH without the need for acidification. Full article
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19 pages, 620 KiB  
Article
Software-Based Transformation of White Light Endoscopy Images to Hyperspectral Images for Improved Gastrointestinal Disease Detection
by Chien-Wei Huang, Chang-Chao Su, Chu-Kuang Chou, Arvind Mukundan, Riya Karmakar, Tsung-Hsien Chen, Pranav Shukla, Devansh Gupta and Hsiang-Chen Wang
Diagnostics 2025, 15(13), 1664; https://doi.org/10.3390/diagnostics15131664 - 30 Jun 2025
Viewed by 544
Abstract
Background/Objectives: Gastrointestinal diseases (GID), such as oesophagitis, polyps, and ulcerative colitis, contribute significantly to global morbidity and mortality. Conventional diagnostic methods employing white light imaging (WLI) in wireless capsule endoscopy (WCE) provide limited spectrum information, therefore influencing classification performance. Methods: A new technique [...] Read more.
Background/Objectives: Gastrointestinal diseases (GID), such as oesophagitis, polyps, and ulcerative colitis, contribute significantly to global morbidity and mortality. Conventional diagnostic methods employing white light imaging (WLI) in wireless capsule endoscopy (WCE) provide limited spectrum information, therefore influencing classification performance. Methods: A new technique called Spectrum Aided Vision Enhancer (SAVE), which converts traditional WLI images into hyperspectral imaging (HSI)-like representations, hence improving diagnostic accuracy. HSI involves the acquisition of image data across numerous wavelengths of light, extending beyond the visible spectrum, to deliver comprehensive information regarding the material composition and attributes of the imaged objects. This technique facilitates improved tissue characterisation, rendering it especially effective for identifying abnormalities in medical imaging. Using a carefully selected dataset consisting of 6000 annotated photos taken from the KVASIR and ETIS-Larib Polyp Database, this work classifies normal, ulcers, polyps, and oesophagitis. The performance of both the original WLI and SAVE transformed images was assessed using advanced deep learning architectures. The principal outcome was the overall classification accuracy for normal, ulcer, polyp, and oesophagitis categories, contrasting SAVE-enhanced images with standard WLI across five deep learning models. Results: The principal outcome of this study was the enhancement of diagnostic accuracy for gastrointestinal disease classification, assessed through classification accuracy, precision, recall, and F1 score. The findings illustrate the efficacy of the SAVE method in improving diagnostic performance without requiring specialised equipment. With the best accuracy of 98% attained using EfficientNetB7, compared to 97% with WLI, experimental data show that SAVE greatly increases classification metrics across all models. With relative improvement from 85% (WLI) to 92% (SAVE), VGG16 showed the highest accuracy. Conclusions: These results confirm that the SAVE algorithm significantly improves the early identification and classification of GID, therefore providing a potential development towards more accurate, non-invasive GID diagnostics with WCE. Full article
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18 pages, 2098 KiB  
Article
Development and Validation of the Children’s Emotions Database (CED): Preschoolers’ Basic and Complex Facial Expressions
by Nadia Koltcheva and Ivo D. Popivanov
Children 2025, 12(7), 816; https://doi.org/10.3390/children12070816 - 21 Jun 2025
Cited by 1 | Viewed by 481
Abstract
Background. Emotions are a crucial part of our human nature. The recognition of emotions is an essential component of our social and emotional skills. Facial expressions serve as a key element in discerning others’ emotions. Different databases of images of facial emotion [...] Read more.
Background. Emotions are a crucial part of our human nature. The recognition of emotions is an essential component of our social and emotional skills. Facial expressions serve as a key element in discerning others’ emotions. Different databases of images of facial emotion expressions exist worldwide; however, most of them are limited to only adult faces and include only the six basic emotions, as well as neutral faces, ignoring more complex emotional expressions. Here, we present the Children’s Emotions Database (CED), a novel repository featuring both basic and complex facial expressions captured from preschool-aged children. The CED is one of the first databases to include complex emotional expressions in preschoolers. Our aim was to develop such a database that can be used further for research and applied purposes. Methods. Three 6-year-old children (one female) were photographed while showing different facial emotional expressions. The photos were taken under standardized conditions. The children were instructed to express each of the following basic emotions: happiness, pleasant surprise, sadness, fear, anger, disgust; a neutral face; and four complex emotions: pride, guilt, compassion, and shame; this resulted in a total of eleven expressions for each child. Two photos per child were reviewed and selected for validation. The photo validation was performed with a sample of 104 adult raters (94 females; aged 19–70 years; M = 29.9; SD = 11.40) and a limited sample of 32 children at preschool age (17 girls; aged 4–7 years; M = 6.5; SD = 0.81). The validation consisted of two tasks—free emotion labeling and emotion recognition (with predefined labels). Recognition accuracy for each expression was calculated. Results and Conclusions. While basic emotions and neutral expressions were recognized with high accuracy, complex emotions were less accurately identified, consistent with the existing literature on the developmental challenges in recognizing such emotions. The current work is a promising new database of preschoolers’ facial expressions consisting of both basic and complex emotions. This database offers a valuable resource for advancing research in emotional development, educational interventions, and clinical applications tailored to early childhood. Full article
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13 pages, 3003 KiB  
Article
Nematic Phases in Photo-Responsive Hydrogen-Bonded Liquid Crystalline Dimers
by Christian Anders, Muhammad Abu Bakar, Tejal Nirgude and Mohamed Alaasar
Crystals 2025, 15(6), 576; https://doi.org/10.3390/cryst15060576 - 18 Jun 2025
Viewed by 374
Abstract
We report on the preparation and characterization of a new family of hydrogen-bonded nematogenic liquid crystalline dimers. The dimers are supramolecular complexes that consist of a benzoic acid derivative, acting as the proton donor, featuring a spacer with seven methylene groups and a [...] Read more.
We report on the preparation and characterization of a new family of hydrogen-bonded nematogenic liquid crystalline dimers. The dimers are supramolecular complexes that consist of a benzoic acid derivative, acting as the proton donor, featuring a spacer with seven methylene groups and a terminal decyloxy chain, paired with an azopyridine derivative as the proton acceptor. The latter was either fluorinated or nonfluorinated with variable alkoxy chain length. The formation of a hydrogen bond between the individual components was confirmed using FTIR and 1H NMR spectroscopy. All supramolecules were investigated for their liquid crystalline behaviour via a polarized optical microscope (POM) and differential scanning calorimetry (DSC). All materials exhibit enantiotropic nematic phases as confirmed by X-ray diffraction (XRD) and POM investigations. The nematic phase range depends strongly on the degree and position of fluorine atoms. Additionally, the supramolecules demonstrated a rapid and reversible transition between the liquid crystal phase and the isotropic liquid state because of trans-cis photoisomerization upon light irradiation. Therefore, this study presents a straightforward approach to design photo-responsive nematic materials, which could be of interest for nonlinear optics applications. Full article
(This article belongs to the Special Issue Celebrating the 10th Anniversary of International Crystallography)
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15 pages, 6874 KiB  
Article
Automated Image-Based Wound Area Assessment in Outpatient Clinics Using Computer-Aided Methods: A Development and Validation Study
by Kuan-Chen Li, Ying-Han Lee and Yu-Hsien Lin
Medicina 2025, 61(6), 1099; https://doi.org/10.3390/medicina61061099 - 17 Jun 2025
Viewed by 689
Abstract
Background and Objectives: Traditionally, we evaluate the size of a wound by using Opsite Flexigrid transparent film dressing, placing it over the wound, tracing the edges of the wound, and then calculating the area. However, this method is both time-consuming and subjective, often [...] Read more.
Background and Objectives: Traditionally, we evaluate the size of a wound by using Opsite Flexigrid transparent film dressing, placing it over the wound, tracing the edges of the wound, and then calculating the area. However, this method is both time-consuming and subjective, often leading to varying results depending on the individual performing the assessment. In this study, our goal is to provide an objective method to calculate the wound size and solve variations in photo-taking distance caused by different medical practitioners or at different times, as these can lead to inaccurate wound size assessments. To evaluate this, we employed K-means clustering and used a QR code as a reference to analyze images of the same wound captured at varying distances, objectively quantifying the areas of 40 wounds. This study aims to develop an objective method for calculating the wound size, addressing variations in photo-taking distance that occur across different medical personnel or time points—factors that can compromise measurement accuracy. By improving consistency and reducing the manual workload, this approach also seeks to enhance the efficiency of healthcare providers. We applied K-means clustering for wound segmentation and used a QR code as a spatial reference. Images of the same wounds taken at varying distances were analyzed, and the wound areas of 40 cases were objectively quantified. Materials and Methods: We employed K-means clustering and used a QR code as a reference to analyze wound photos taken by different medical practitioners in the outpatient consulting room. K-means clustering is a machine learning algorithm that segments the wound region by grouping pixels in an image according to their color similarity. It organizes data points into clusters based on shared features. Based on this algorithm, we can use it to identify the wound region and determine its pixel area. We also used a QR code as a reference because of its unique graphical pattern. We used the printed QR code on the patient’s identification sticker as a reference for length. By calculating the ratio of the number of pixels within the square area of the QR code to its actual area, we applied this ratio to the detected wound pixel area, enabling us to calculate the wound’s actual size. The printed patient identification stickers were all uniform in size and format, allowing us to apply this method consistently to every patient. Results: The results support the accuracy of our algorithm when tested on a standard one-cent coin. The paired t-test comparing the first and second photos shot yielded a p-value of 0.370, indicating no significant difference between the two. Similarly, the t-test comparing the first and third photos shot produced a p-value of 0.179, also showing no significant difference. The comparison between the second and third photos shot resulted in a p-value of 0.547, again indicating no significant difference. Since all p-values are greater than 0.05, none of the test pairs show statistically significant differences. These findings suggest that the three randomly taken photo shots produce consistent results and can be considered equivalent. Conclusions: Our algorithm for wound area assessment is highly reliable, interchangeable, and consistently produces accurate results. This objective and practical method can aid clinical decision-making by tracking wound progression over time. Full article
(This article belongs to the Section Surgery)
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19 pages, 2152 KiB  
Article
Instagram Engagement and Content Strategies of US and UK Legacy Media: A Quantitative Analysis of Five Leading News Outlets
by Douglas Farias Cordeiro, Mari Vállez, Cristina I. Font-Julian and Javier Guallar
Journal. Media 2025, 6(2), 89; https://doi.org/10.3390/journalmedia6020089 - 16 Jun 2025
Viewed by 1520
Abstract
The digital age, driven by advancements in data processing and internet technologies, has seen virtual social networks, particularly Instagram, become integral to daily life, influencing both leisure and professional activities. Instagram, with over two billion users in 2023, emphasizes visual storytelling, making it [...] Read more.
The digital age, driven by advancements in data processing and internet technologies, has seen virtual social networks, particularly Instagram, become integral to daily life, influencing both leisure and professional activities. Instagram, with over two billion users in 2023, emphasizes visual storytelling, making it a pivotal platform for media outlets to engage audiences through photos and videos. This study quantitatively analyses the Instagram engagement and content strategies of five prominent legacy news outlets from the United States and the United Kingdom—The New York Times, The Guardian, USA Today, The Independent, and The Washington Post. Through an examination of over 9000 posts from January to December 2023, this research evaluates posting frequency, user engagement (likes and comments), hashtag usage, profile mentions, and geographic coverage. Findings indicate significant differences in posting strategies and engagement levels, highlighting The Washington Post’s intensive posting and The Guardian’s selective engagement strategy. This study emphasizes tailored strategies, thematic consistency, and careful use of mentions and hashtags as crucial for maximizing audience interaction. Full article
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15 pages, 1327 KiB  
Article
Aesthetic Impact of Orthognathic Surgery vs. Orthodontic Camouflage in Class II Division 1 Patients with Convex Facial Profile: A Follow-Up Using Combined Frontal and Profile Views
by Simos Psomiadis, Iosif Sifakakis, Ioannis Iatrou and Nikolaos Gkantidis
J. Clin. Med. 2025, 14(12), 4277; https://doi.org/10.3390/jcm14124277 - 16 Jun 2025
Viewed by 897
Abstract
Background/Objectives: A previous study evaluating convex facial profiles at rest demonstrated that combined orthodontic and orthognathic surgical treatment is more effective in enhancing facial aesthetics compared to orthodontic camouflage alone. The present follow-up study aimed to reassess these findings by incorporating both [...] Read more.
Background/Objectives: A previous study evaluating convex facial profiles at rest demonstrated that combined orthodontic and orthognathic surgical treatment is more effective in enhancing facial aesthetics compared to orthodontic camouflage alone. The present follow-up study aimed to reassess these findings by incorporating both profile and frontal facial views in the aesthetic evaluation. Methods: This retrospective cohort study sample included 36 consecutively selected patients with convex facial profiles and Class II Division 1 malocclusion. Two groups of 18 non-growing patients with similar characteristics were compared. Group A was treated with orthodontics and orthognathic surgery, whereas Group B was treated with orthodontics exclusively. Pre- and post-treatment profile and frontal facial photographs were simultaneously presented to orthodontists, oral and maxillofacial surgeons, convex profile patients, and laypeople, asking them to assess changes in facial appearance. Results: Significant positive changes in facial appearance were perceived for Group A, in contrast to no changes for Group B, with a difference of 17/100 visual analogue scale (VAS) units. The rater groups demonstrated a high degree of consistency (ICC > 0.88). Multivariate analysis revealed significant differences in perceived changes between the two treatment groups (F = 14.63, p < 0.001, Pillai’s Trace = 0.36, and partial η2 = 0.36), with no significant effects from the rater group (p > 0.05). Similar results are evident when only profile photos were rated (p > 0.05). Conclusions: The combined orthodontic and orthognathic surgery approach effectively enhances facial appearance in convex profile cases, whereas orthodontic treatment alone does not result in significant changes. These findings should be clearly communicated during patient consultations and considered in treatment planning. Full article
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13 pages, 1228 KiB  
Article
Medical Photography in Dermatology: Quality and Safety in the Referral Process to Secondary Healthcare
by Eduarda Castro Almeida, João Rocha-Neves, Ana Filipa Pedrosa and José Paulo Andrade
Diagnostics 2025, 15(12), 1518; https://doi.org/10.3390/diagnostics15121518 - 14 Jun 2025
Viewed by 492
Abstract
Background: Medical photography is widely used in dermatology referrals to secondary healthcare, yet concerns exist regarding image quality and data security. This study aimed to evaluate the quality of clinical photographs used in dermatology referrals, to identify discrepancies between specialties’ perceptions, and to [...] Read more.
Background: Medical photography is widely used in dermatology referrals to secondary healthcare, yet concerns exist regarding image quality and data security. This study aimed to evaluate the quality of clinical photographs used in dermatology referrals, to identify discrepancies between specialties’ perceptions, and to determine the general awareness of proper storage and security of clinical photographs. Methods: A 43-question survey, based on previously validated questionnaires, was administered to general and family medicine (GFM) doctors and to dermatologists at an academic referral hospital in Porto, Portugal. The survey assessed demographics, photo-taking habits, perceived photo quality, adequacy of clinical information, and opinions on the role of photography in the referral process. Quantitative statistical methods were used to analyze questionnaire responses. Results: A total of 65 physicians participated (18 dermatologists and 47 GFM doctors). Significant differences were observed between the two groups. While 36.2% of GFMs rated their submitted photos as high- or very-high-quality, none of the dermatologists rated the received photos as high-quality, with 83.3% rating them as average (p = 0.012). Regarding clinical information, 46.8% of GFMs reported consistently sending enough information, while no dermatologists reported always receiving sufficient information (p < 0.001). Most respondents (76.9%) agreed that the quality of photographs is important in diagnosis and treatment. Conclusions: The findings reveal a discrepancy between GFM doctors’ and dermatologists’ perceptions of photograph quality and information sufficiency in dermatology referrals. Standardized guidelines and educational interventions are necessary to improve the quality and consistency of clinical photographs, thereby enhancing communication between healthcare providers and ensuring patient data privacy and security. Full article
(This article belongs to the Section Medical Imaging and Theranostics)
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18 pages, 43879 KiB  
Article
Using AI to Reconstruct and Preserve 3D Temple Art with Old Images
by Naai-Jung Shih
Technologies 2025, 13(6), 229; https://doi.org/10.3390/technologies13060229 - 3 Jun 2025
Viewed by 841
Abstract
How can AI help us connect to the past in terms of conservation? How can 17-year-old photos be helpful in renewed preservation efforts? This research aims to use AI to connect both in a seamless 3D reconstruction of heritage from images taken of [...] Read more.
How can AI help us connect to the past in terms of conservation? How can 17-year-old photos be helpful in renewed preservation efforts? This research aims to use AI to connect both in a seamless 3D reconstruction of heritage from images taken of Gongfan Palace, Yunlin, Taiwan. AI-assisted 3D modeling was used to reconstruct the details of these images across different 3D platforms of the 3DGS or NeRF models generated by Postshot®, RODIN®, and KIRI Engine®. Mesh and point models created using Zephyr® were referred to and assessed in three sets. The consistent and inconsistent reconstructed results also included AI-assisted modeling outcomes in Stable Diffusion®- and Postshot®-based animations, followed by a 3D assessment and section-based composition analysis. The AI-assisted environment concluded with a recursive reconstruction involving 3D models and 2D images. AI assisted the 3D modeling process in an alternative approach, producing extraordinary structural and visual details. AI-trained models can be assessed and their use extended to composition analysis by section. Evolved documentation and interpretation using AI enables new structures and the management of resources, formats, and interfaces as part of continuous preservation efforts. Full article
(This article belongs to the Section Construction Technologies)
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14 pages, 2119 KiB  
Article
Hydrodynamic Cavitation-Assisted Photo-Fenton Pretreatment and Yeast Co-Culture as Strategies to Produce Ethanol and Xylitol from Sugarcane Bagasse
by Carina Aline Prado, Ana Júlia E. B. da Silva, Paulo A. F. H. P. Fernandes, Vinicius P. Shibukawa, Fanny M. Jofre, Bruna G. Rodrigues, Silvio Silvério da Silva, Solange I. Mussatto and Júlio César Santos
Catalysts 2025, 15(5), 418; https://doi.org/10.3390/catal15050418 - 24 Apr 2025
Viewed by 548
Abstract
This study explored innovative approaches to produce ethanol and xylitol from sugarcane bagasse using a hydrodynamic cavitation-assisted photo-Fenton process as the pretreatment, and yeast co-culture for hydrolysate fermentation. Pretreatment conditions were optimized (20 mg/L of iron sulfate, pH 5.0, and reaction time of [...] Read more.
This study explored innovative approaches to produce ethanol and xylitol from sugarcane bagasse using a hydrodynamic cavitation-assisted photo-Fenton process as the pretreatment, and yeast co-culture for hydrolysate fermentation. Pretreatment conditions were optimized (20 mg/L of iron sulfate, pH 5.0, and reaction time of 14 min) resulting in glucan and xylan hydrolysis yields of 96% and 89%, respectively. The hydrolysate produced under these conditions was fermented using a co-culture of Saccharomyces cerevisiae IR2 (an ethanol-producing strain) and Candida tropicalis UFMGBX12 (a xylitol-producing strain). Optimal co-culture conditions consisted of using an inoculum concentration of 1.5 g/L for each yeast strain. After 36 h of fermentation, ethanol and xylitol concentrations reached 20 g/L and 13 g/L, respectively. These results demonstrate the potential of combining hydrodynamic cavitation-assisted photo-Fenton pretreatment with co-culture fermentation to simultaneously produce ethanol and xylitol. This strategy presents a promising approach for enhancing the efficiency of lignocellulosic biorefineries. Full article
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16 pages, 4066 KiB  
Article
Development of a Reliable Device for ‘Fluorokinetic’ Analysis Based on a Portable Diode Array MEMS Fluorimeter
by Domingo González-Arjona and Germán López-Pérez
Chemosensors 2025, 13(4), 128; https://doi.org/10.3390/chemosensors13040128 - 3 Apr 2025
Viewed by 2633
Abstract
A device was developed to study the evolution of fluorescence spectra as a function of time. A previously designed fluorimeter based on the diode array mini-spectrometer CM12880MA was used. The control and measurement were carried out by programming a SAM21D microcontroller. Considerations regarding [...] Read more.
A device was developed to study the evolution of fluorescence spectra as a function of time. A previously designed fluorimeter based on the diode array mini-spectrometer CM12880MA was used. The control and measurement were carried out by programming a SAM21D microcontroller. Considerations regarding the optimization of acquisition speed, memory, and computer interface have been analyzed and optimized. As a result, a very versatile device with great adaptability, reduced dimensions, portability, and a low budget (under EUR 500) has been built. The sensitivity, controlled by the integration time of the photodiodes, can be adjusted between 10 µs and 20 s, thus allowing sampling times ranging from 10 ms to more than 10 h. Under these conditions, chemical rate constants from 20 s−1 to 10−8 s−1 can be experimentally determined. It has a very wide operating range for the kinetic rate constant determination, over six orders of magnitude. As proof of the system performance, the oxidation reaction of Thiamine in a basic medium to form fluorescent Thiochrome has been employed. The evolution of the emission spectrum has been followed, and the decomposition rate constant has been measured at 2.1 × 10−3 s−1, a value which matches those values reported in the literature for this system. A Thiochrome calibration curve has also been performed, obtaining a detection limit of 13 nM, consistent with literature data. Additionally, the stability of Thiochrome has been tested, being the photo-decomposition rate constants 1.8 × 10−4 s−1 and 3.0 × 10−7 s−1, in the presence and absence of UV light (365 nm), respectively. Finally, experiments have been designed to obtain, in a single measurement, the values of both rate constants: the formation of Thiochrome from Thiamine and its photo-decomposition under UV light to a non-fluorescent product. The rate constant values obtained are in good agreement with those previously obtained through independent experiments under the same experimental conditions. These results show that, under these conditions, Thiochrome can be considered an unstable intermediate in a chemical reaction with successive stages. Full article
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24 pages, 4805 KiB  
Article
A Computational Analysis Based on Automatic Digitization of Movement Tracks Reveals the Altered Diurnal Behavior of the Western Flower Thrips, Frankliniella occidentalis, Suppressed in PKG Expression
by Chunlei Xia, Gahyeon Jin, Falguni Khan, Hye-Won Kim, Yong-Hyeok Jang, Nam Jung, Yonggyun Kim and Tae-Soo Chon
Insects 2025, 16(3), 320; https://doi.org/10.3390/insects16030320 - 19 Mar 2025
Viewed by 556
Abstract
The western flower thrips, Frankliniella occidentalis, a worldwide insect pest with its polyphagous feeding behavior and capacity to transmit viruses, follows a diurnal rhythmicity driven by expression of the circadian clock genes. However, it remained unclear how the clock signal triggers the [...] Read more.
The western flower thrips, Frankliniella occidentalis, a worldwide insect pest with its polyphagous feeding behavior and capacity to transmit viruses, follows a diurnal rhythmicity driven by expression of the circadian clock genes. However, it remained unclear how the clock signal triggers the thrips behaviors. This study posed a hypothesis that the clock signal modulates cGMP-dependent protein kinase (PKG) activity to mediate the diurnal behaviors. A PKG gene is encoded in F. occidentalis and exhibits high sequence homologies with those of honeybee and fruit fly. Interestingly, its expression followed a diel pattern with high expression during photophase in larvae and adults of F. occidentalis. It is noteworthy that PKG expression was clearly observed in the midgut during photophase but not in scotophase from our fluorescence in situ hybridization analysis. A prediction of protein–protein interaction suggested its functional association with clock genes. To test this functional link, RNA interference (RNAi) of the PKG gene expression was performed by feeding a gene-specific double-stranded RNA, which led to significant alteration of the two clock genes (Clock and Period) in their expression levels. The RNAi treatment caused adverse effects on early-life development and adult fecundity. To further analyze the role of PKG in affecting diurnal behavior, the adult females were continuously observed for a 24 h period with an automatic digitization device to obtain movement parameters and durations (%) in different micro-areas in the observation arena. Diel difference was observed with speed in RNAi-control females at 0.16 mm/s and 0.08 mm/s, in photo- and scotophase, respectively, whereas diel difference was not observed for the PKG-specific RNAi-treated females, which showed 0.07 mm/s and 0.06 mm/s, respectively. The diel difference was also observed in durations (%) in the control females, more strongly in the intermediate area in the observation arena. Speed and durations in the different micro-areas in mid-scotophase were significantly different from most photophase in the control females, while speed was significantly different mainly during late photophase when comparing effects of control and RNAi treatments in each light phase. Three sequential stages consisting of high activity followed by feeding and visiting of micro-areas were observed for the control females. For RNAi-treated females, the three phases were disturbed with irregular speed and visits to micro-areas. These results suggest that PKG is associated with implementing the diurnal behavior of F. occidentalis by interacting with expressions of the circadian clock genes. Full article
(This article belongs to the Section Insect Physiology, Reproduction and Development)
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27 pages, 4252 KiB  
Article
Facial Privacy Protection with Dynamic Multi-User Access Control for Online Photo Platforms
by Andri Santoso, Samsul Huda, Yuta Kodera and Yasuyuki Nogami
Future Internet 2025, 17(3), 124; https://doi.org/10.3390/fi17030124 - 11 Mar 2025
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Abstract
In the digital age, sharing moments through photos has become a daily habit. However, every face captured in these photos is vulnerable to unauthorized identification and potential misuse through AI-powered synthetic content generation. Previously, we introduced SnapSafe, a secure system for enabling selective [...] Read more.
In the digital age, sharing moments through photos has become a daily habit. However, every face captured in these photos is vulnerable to unauthorized identification and potential misuse through AI-powered synthetic content generation. Previously, we introduced SnapSafe, a secure system for enabling selective image privacy focusing on facial regions for single-party scenarios. Recognizing that group photos with multiple subjects are a more common scenario, we extend SnapSafe to support multi-user facial privacy protection with dynamic access control designed for online photo platforms. Our approach introduces key splitting for access control, an owner-centric permission system for granting and revoking access to facial regions, and a request-based mechanism allowing subjects to initiate access permissions. These features ensure that facial regions remain protected while maintaining the visibility of non-facial content for general viewing. To ensure reproducibility and isolation, we implemented our solution using Docker containers. Our experimental assessment covered diverse scenarios, categorized as “Single”, “Small”, “Medium”, and “Large”, based on the number of faces in the photos. The results demonstrate the system’s effectiveness across all test scenarios, consistently performing face encryption operations in under 350 ms and achieving average face decryption times below 286 ms across various group sizes. The key-splitting operations maintained a 100% success rate across all group configurations, while revocation operations were executed efficiently with server processing times remaining under 16 ms. These results validate the system’s capability in managing facial privacy while maintaining practical usability in online photo sharing contexts. Full article
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