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26 pages, 7634 KiB  
Article
Research on the Preparation and Performance of Wood with High Negative Oxygen Ion Release Induced by Moisture
by Min Yin, Yuqi Zhang, Yun Lu, Zongying Fu, Haina Mi, Jianfang Yu and Ximing Wang
Coatings 2025, 15(8), 905; https://doi.org/10.3390/coatings15080905 (registering DOI) - 2 Aug 2025
Abstract
With the growing severity of environmental pollution, people are paying increasing attention to their health. However, naturally occurring wood with health benefits and applications in human healthcare is still scarce. Natural wood exhibits a limited negative oxygen ion release capacity, and this release [...] Read more.
With the growing severity of environmental pollution, people are paying increasing attention to their health. However, naturally occurring wood with health benefits and applications in human healthcare is still scarce. Natural wood exhibits a limited negative oxygen ion release capacity, and this release has a short duration, failing to meet practical application requirements. This study innovatively developed a humidity-responsive, healthy wood material with a high negative oxygen ion release capacity based on fast-growing poplar. Through vacuum cyclic impregnation technology, hexagonal stone powder was infused into the pores of poplar wood, endowing it with the ability to continuously release negative oxygen ions. The healthy wood demonstrated a static average negative oxygen ion release rate of 537 ions/cm3 (peaking at 617 ions/cm3) and a dynamic average release rate of 3,170 ions/cm3 (peaking at 10,590 ions/cm3). The results showed that the particle size of hexagonal stone powder in suspension was influenced by the dispersants and dispersion processes. The composite dispersion process demonstrated optimal performance when using 0.5 wt% silane coupling agent γ-(methacryloxy)propyltrimethoxysilane (KH570), achieving the smallest particle size of 8.93 μm. The healthy wood demonstrated excellent impregnation performance, with a weight gain exceeding 14.61% and a liquid absorption rate surpassing 165.18%. The optimal impregnation cycle for vacuum circulation technology was determined to be six cycles, regardless of the type of dispersant. Compared with poplar wood, the hygroscopic swelling rate of healthy wood was lower, especially in PEG-treated samples, where the tangential, radial, longitudinal, and volumetric swelling rates decreased by 70.93%, 71.67%, 69.41%, and 71.35%, respectively. Combining hexagonal stone powder with fast-growing poplar wood can effectively enhance the release of negative oxygen ions. The static average release of negative oxygen ions from healthy wood is 1.44 times that of untreated hexagonal stone powder, and the dynamic release reaches 2 to 3 times the concentration of negative oxygen ions specified by national fresh air standards. The water-responsive mechanism revealed that negative oxygen ion release surged when ambient humidity exceeded 70%. This work proposes a sustainable and effective method to prepare healthy wood with permanent negative oxygen ion release capability. It demonstrates great potential for improving indoor air quality and enhancing human health. Full article
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22 pages, 1556 KiB  
Article
Long-Term Performance of Passive Volatile Organic Compounds (VOCs) Samplers for Indoor Air
by John H. Zimmerman, Brian Schumacher, Christopher C. Lutes, Brian Cosky and Heidi Hayes
Environments 2025, 12(8), 267; https://doi.org/10.3390/environments12080267 (registering DOI) - 31 Jul 2025
Viewed by 168
Abstract
The reliability of passive samplers in measuring volatile organic compounds (VOCs) in indoor air depends on whether the uptake rate is constant given the environmental conditions and sampler exposure duration. The first phase of this study evaluated the performance of charcoal-based, solvent-extracted passive [...] Read more.
The reliability of passive samplers in measuring volatile organic compounds (VOCs) in indoor air depends on whether the uptake rate is constant given the environmental conditions and sampler exposure duration. The first phase of this study evaluated the performance of charcoal-based, solvent-extracted passive samplers (e.g., Radiello® 130 passive samplers with white diffusive bodies) over exposure periods ranging from 1 week to 1 year in a test house with known vapor intrusion (VI). Chloroform %Bias values exceeded the ±30% acceptance criterion after 4 weeks exposure. Benzene, hexane, and trichloroethylene (TCE) concentrations were within the acceptance criterion for up to three months. Toluene and tetrachloroethylene (PCE), the two least volatile compounds, demonstrated uniform uptake rates over one year. In the second phase of this study, testing of the longer exposure times of 6 months and 1 year were evaluated with three additional passive samplers: Waterloo Membrane SamplerTM (WMSTM), SKC 575 with secondary diffusive cover, and Radiello® 130 passive samplers with yellow diffusive bodies. The SKC 575 and Radiello® 130 passive samplers produced acceptable results (%Bias ≤ 30%) over the 6-month exposure period, while the WMSTM sampler results favored petroleum hydrocarbon more than chlorinated solvent uptake. After the 1-year exposure period, the passive sampler performances were acceptable under specific conditions of this study. The results suggest that all three samplers can produce acceptable results over exposure time periods beyond 30 days and up to a year for some compounds. Full article
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19 pages, 4690 KiB  
Article
Immune-Redox Biomarker Responses to Short- and Long-Term Exposure to Naturally Emitted Compounds from Korean Red Pine (Pinus densiflora) and Japanese Cypress (Chamaecyparis obtusa): In Vivo Study
by Hui Ma, Jiyoon Yang, Chang-Deuk Eom, Johny Bajgai, Md. Habibur Rahman, Thu Thao Pham, Haiyang Zhang, Won-Joung Hwang, Seong Hoon Goh, Bomi Kim, Cheol-Su Kim, Keon-Ho Kim and Kyu-Jae Lee
Toxics 2025, 13(8), 650; https://doi.org/10.3390/toxics13080650 (registering DOI) - 31 Jul 2025
Viewed by 162
Abstract
Volatile organic compounds (VOCs) are highly volatile chemicals in natural and anthropogenic environments, significantly affecting indoor air quality. Major sources of indoor VOCs include emissions from building materials, furnishings, and consumer products. Natural wood products release VOCs, including terpenes and aldehydes, which exert [...] Read more.
Volatile organic compounds (VOCs) are highly volatile chemicals in natural and anthropogenic environments, significantly affecting indoor air quality. Major sources of indoor VOCs include emissions from building materials, furnishings, and consumer products. Natural wood products release VOCs, including terpenes and aldehydes, which exert diverse health effects ranging from mild respiratory irritation to severe outcomes, such as formaldehyde-induced carcinogenicity. The temporal dynamics of VOC emissions were investigated, and the toxicological and physiological effects of the VOCs emitted by two types of natural wood, Korean Red Pine (Pinus densiflora) and Japanese Cypress (Chamaecyparis obtusa), were evaluated. Using female C57BL/6 mice as an animal model, the exposure setups included phytoncides, formaldehyde, and intact wood samples over short- and long-term durations. The exposure effects were assessed using oxidative stress markers, antioxidant enzyme activity, hepatic and renal biomarkers, and inflammatory cytokine profiles. Long-term exposure to Korean Red Pine and Japanese Cypress wood VOCs did not induce significant pathological changes. Japanese Cypress exhibited more distinct benefits, including enhanced oxidative stress mitigation, reduced systemic toxicity, and lower pro-inflammatory cytokine levels compared to the negative control group, attributable to its more favorable VOC emission profile. These findings highlight the potential health and environmental benefits of natural wood VOCs and offer valuable insights for optimizing timber use, improving indoor air quality, and informing public health policies. Full article
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11 pages, 2215 KiB  
Article
Dysbiosis in the Nasal Mycobiome of Infants Born in the Aftermath of Hurricane Maria
by Ruochen Wang, David de Ángel Solá, Félix E. Rivera-Mariani, Benjamín Bolaños Rosero, Nicolás Rosario Matos and Leyao Wang
Microorganisms 2025, 13(8), 1784; https://doi.org/10.3390/microorganisms13081784 - 31 Jul 2025
Viewed by 246
Abstract
Hurricanes and flooding events substantially elevate indoor fungal spore levels, which have been associated with increased risks of developing childhood asthma and other adverse respiratory outcomes. Although environmental fungal compositions following major hurricanes have been well characterized, the fungal communities within the nasal [...] Read more.
Hurricanes and flooding events substantially elevate indoor fungal spore levels, which have been associated with increased risks of developing childhood asthma and other adverse respiratory outcomes. Although environmental fungal compositions following major hurricanes have been well characterized, the fungal communities within the nasal cavity (i.e., the nasal mycobiome) of exposed individuals remain unexplored. We collected nasal swab samples from infants following Hurricane Maria in San Juan, Puerto Rico, during two periods (March to August 2018 and February to September 2019). We processed a total of 58 samples (26 from the first year and 32 from the second year post-Hurricane Maria) and performed internally transcribed spacer (ITS) rRNA gene sequencing to characterize and compare the infant nasal mycobiome between the two groups. Although alpha-diversity did not differ significantly, beta-diversity analyses revealed significantly different fungal compositions between the two groups (p <0.01). Infants exposed during the first year post-Hurricane Maria had significantly higher abundances of Alternaria, Eutypella, Schizophyllum, and Auricularia, compared to infants from the second year. Alternaria was also more prevalent in the first-year than in the second-year infants (42% vs. 9%, p = 0.01). Our study provides evidence linking early-life hurricane exposures to elevated risks of developing childhood asthma. Full article
(This article belongs to the Special Issue Fungi and Health)
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22 pages, 3131 KiB  
Article
CAREC: Continual Wireless Action Recognition with Expansion–Compression Coordination
by Tingting Zhang, Qunhang Fu, Han Ding, Ge Wang and Fei Wang
Sensors 2025, 25(15), 4706; https://doi.org/10.3390/s25154706 - 30 Jul 2025
Viewed by 267
Abstract
In real-world applications, user demands for new functionalities and activities constantly evolve, requiring action recognition systems to incrementally incorporate new action classes without retraining from scratch. This class-incremental learning (CIL) paradigm is essential for enabling adaptive and scalable systems that can grow over [...] Read more.
In real-world applications, user demands for new functionalities and activities constantly evolve, requiring action recognition systems to incrementally incorporate new action classes without retraining from scratch. This class-incremental learning (CIL) paradigm is essential for enabling adaptive and scalable systems that can grow over time. However, Wi-Fi-based indoor action recognition under incremental learning faces two major challenges: catastrophic forgetting of previously learned knowledge and uncontrolled model expansion as new classes are added. To address these issues, we propose CAREC, a class-incremental framework that balances dynamic model expansion with efficient compression. CAREC adopts a multi-branch architecture to incorporate new classes without compromising previously learned features and leverages balanced knowledge distillation to compress the model by 80% while preserving performance. A data replay strategy retains representative samples of old classes, and a super-feature extractor enhances inter-class discrimination. Evaluated on the large-scale XRF55 dataset, CAREC reduces performance degradation by 51.82% over four incremental stages and achieves 67.84% accuracy with only 21.08 M parameters, 20% parameters compared to conventional approaches. Full article
(This article belongs to the Special Issue Sensor Networks and Communication with AI)
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16 pages, 224 KiB  
Article
Developing a Preliminary List of Indicators for Green Restaurants in Taiwan: An Expert Consensus Approach
by Der-Fa Chen, Chun-Chung Liao, Shang-Hao Cheng, Wen-Jye Shyr and Chin-Chung Huang
Sustainability 2025, 17(15), 6882; https://doi.org/10.3390/su17156882 - 29 Jul 2025
Viewed by 182
Abstract
This study aims to develop a preliminary list of indicators suitable for green restaurants in Taiwan. The research methodology includes expert consensus (Delphi method) and incorporates interviews with field experts. An analysis of the responses provided by these industry experts led to the [...] Read more.
This study aims to develop a preliminary list of indicators suitable for green restaurants in Taiwan. The research methodology includes expert consensus (Delphi method) and incorporates interviews with field experts. An analysis of the responses provided by these industry experts led to the identification of five dimensions of evaluation indicators for green restaurants. The K–S test involves using a z-test on ordinal variables for single samples to determine whether the sample distribution diverges from the frequency distribution. This study analyzed the responses provided by the interviewed experts to identify and extract evaluation indicators for green restaurants. The extracted indicators comprise five dimensions (resource management, ingredient and product selection, environmental and indoor quality, green certification and management, and customer awareness and participation), 15 sub-dimensions, and 70 detailed indicators. The research results can serve as a reference for course planning in related programs at universities and colleges, as well as for industry planning of green restaurants, and as a reference for the promotion of national sustainable environmental policies in Taiwan. Therefore, based on the results of this study, recommendations are provided for educational institutions related to green restaurants, official organizations related to green restaurants, the industry related to green restaurants, and future researchers. Full article
(This article belongs to the Section Environmental Sustainability and Applications)
18 pages, 3870 KiB  
Article
Universal Vector Calibration for Orientation-Invariant 3D Sensor Data
by Wonjoon Son and Lynn Choi
Sensors 2025, 25(15), 4609; https://doi.org/10.3390/s25154609 - 25 Jul 2025
Viewed by 220
Abstract
Modern electronic devices such as smartphones, wearable devices, and robots typically integrate three-dimensional sensors to track the device’s movement in the 3D space. However, sensor measurements in three-dimensional vectors are highly sensitive to device orientation since a slight change in the device’s tilt [...] Read more.
Modern electronic devices such as smartphones, wearable devices, and robots typically integrate three-dimensional sensors to track the device’s movement in the 3D space. However, sensor measurements in three-dimensional vectors are highly sensitive to device orientation since a slight change in the device’s tilt or heading can change the vector values. To avoid complications, applications using these sensors often use only the magnitude of the vector, as in geomagnetic-based indoor positioning, or assume fixed device holding postures such as holding a smartphone in portrait mode only. However, using only the magnitude of the vector loses the directional information, while ad hoc posture assumptions work under controlled laboratory conditions but often fail in real-world scenarios. To resolve these problems, we propose a universal vector calibration algorithm that enables consistent three-dimensional vector measurements for the same physical activity, regardless of device orientation. The algorithm works in two stages. First, it transforms vector values in local coordinates to those in global coordinates by calibrating device tilting using pitch and roll angles computed from the initial vector values. Second, it additionally transforms vector values from the global coordinate to a reference coordinate when the target coordinate is different from the global coordinate by correcting yaw rotation to align with application-specific reference coordinate systems. We evaluated our algorithm on geomagnetic field-based indoor positioning and bidirectional step detection. For indoor positioning, our vector calibration achieved an 83.6% reduction in mismatches between sampled magnetic vectors and magnetic field map vectors and reduced the LSTM-based positioning error from 31.14 m to 0.66 m. For bidirectional step detection, the proposed algorithm with vector calibration improved step detection accuracy from 67.63% to 99.25% and forward/backward classification from 65.54% to 100% across various device orientations. Full article
(This article belongs to the Section Intelligent Sensors)
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16 pages, 5265 KiB  
Article
Crack Development in Compacted Loess Subjected to Wet–Dry Cycles: Experimental Observations and Numerical Modeling
by Yu Xi, Mingming Sun, Gang Li and Jinli Zhang
Buildings 2025, 15(15), 2625; https://doi.org/10.3390/buildings15152625 - 24 Jul 2025
Viewed by 391
Abstract
Loess, a typical soil widely distributed in China, exhibits engineering properties that are highly sensitive to environmental changes, leading to increased erosion and the development of surface cracks. This article examines the influence of initial moisture content, dry density, and thickness on crack [...] Read more.
Loess, a typical soil widely distributed in China, exhibits engineering properties that are highly sensitive to environmental changes, leading to increased erosion and the development of surface cracks. This article examines the influence of initial moisture content, dry density, and thickness on crack formation in compacted loess subjected to wet–dry cycles, using both laboratory experiments and numerical simulation analysis. It quantitatively analyzes the process of crack evolution using digital image processing technology. The experimental results indicate that wet–dry cycles can cause cumulative damage to the soil, significantly encouraging the initiation and expansion of secondary cracks. New cracks often branch out and extend along the existing crack network, demonstrating that the initial crack morphology has a controlling effect over the final crack distribution pattern. Numerical simulations based on MultiFracS software further revealed that soil samples with a thickness of 0.5 cm exhibited more pronounced surface cracking characteristics than those with a thickness of 2 cm, with thinner layers of soil tending to form a more complex network of cracks. The simulation results align closely with the indoor test data, confirming the reliability of the established model in predicting fracture dynamics. The study provides theoretical underpinnings and practical guidance for evaluating the stability of engineering slopes and for managing and mitigating fissure hazards in loess. Full article
(This article belongs to the Special Issue Research on Building Foundations and Underground Engineering)
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22 pages, 5418 KiB  
Article
TickRS: A High-Speed Gapless Signal Sampling Method for Rolling-Shutter Optical Camera Communication
by Yongfeng Hong, Xiangting Xie and Xingfa Shen
Photonics 2025, 12(7), 720; https://doi.org/10.3390/photonics12070720 - 16 Jul 2025
Viewed by 150
Abstract
Using the rolling-shutter mechanism to enhance the signal sampling frequency of Optical Camera Communication (OCC) is a low-cost solution, but its periodic sampling interruptions may cause signal loss, and existing solutions often compromise communication rate and distance. To address this, this paper proposes [...] Read more.
Using the rolling-shutter mechanism to enhance the signal sampling frequency of Optical Camera Communication (OCC) is a low-cost solution, but its periodic sampling interruptions may cause signal loss, and existing solutions often compromise communication rate and distance. To address this, this paper proposes NoGap-RS, a no-gap sampling method, theoretically addressing the signal loss issue at longer distances from a perspective of CMOS exposure timing. Experiments show that NoGap-OOK, a OCC system based on NoGap-RS and On-Off key modulation, can achieve a communication rate of 6.41 Kbps at a distance of 3 m, with a BER of 105 under indoor artificial light. This paper further proposes TickRS, a time slot division method, innovatively addressing the overlap that occurs during consecutive-row exposures to further enhance communication rate. Experiments show that TickRS-CSK, a OCC system based on TickRS and Color-Shift Key, can achieve a communication rate of 20.09 Kbps at a distance of 3.6 m, with a BER of 102 under indoor natural light. Full article
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29 pages, 4517 KiB  
Article
Bioengineered Indoor Farming Approaches: LED Light Spectra and Biostimulants for Enhancing Vindoline and Catharanthine Production in Catharanthus roseus
by Alessandro Quadri, Bianca Sambuco, Mattia Trenta, Patrizia Tassinari, Daniele Torreggiani, Laura Mercolini, Michele Protti, Alessandra Zambonelli, Federico Puliga and Alberto Barbaresi
Horticulturae 2025, 11(7), 828; https://doi.org/10.3390/horticulturae11070828 - 12 Jul 2025
Viewed by 395
Abstract
Light quality and biostimulants regulate alkaloid biosynthesis and promote plant growth, but their combined effects on vindoline (VDL) and catharanthine (CAT) production in Catharanthus roseus remain underexplored. This study investigated the impact of different LED spectra and an arbuscular mycorrhizal fungi-based biostimulant (BS) [...] Read more.
Light quality and biostimulants regulate alkaloid biosynthesis and promote plant growth, but their combined effects on vindoline (VDL) and catharanthine (CAT) production in Catharanthus roseus remain underexplored. This study investigated the impact of different LED spectra and an arbuscular mycorrhizal fungi-based biostimulant (BS) on VDL and CAT production in indoor-grown C. roseus. After a 60-day pretreatment under white LEDs, plants were exposed to eight treatments: white (W, control), red (R), blue (B), and red-blue (RB) light, and their combinations with BS. Samples were collected before treatments (T0) and 92 days after pretreatment (T1). No mycorrhizal development was observed. VDL was detected in both roots and leaves, with higher levels in roots. R produced significantly higher mean concentrations of both VDL and CAT than W. BS significantly increased mean concentrations and total yields of both alkaloids than the untreated condition. The combination of R and BS produced the highest mean concentrations and total yields of VDL and CAT. In particular, it resulted in a significantly higher mean concentration and total yield of VDL compared to sole W. Total yields increased from T0 to T1, primarily due to a substantial rise in root yield. In conclusion, combining R and BS proved to be the most effective strategy to enhance VDL and CAT production by maximizing their total yields, which also increased over time due to greater root contribution. This underscores the importance of combining targeted treatments with harvesting at specific stages to optimize alkaloid production under controlled conditions. Full article
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13 pages, 1084 KiB  
Article
Airborne SARS-CoV-2 Detection by ddPCR in Adequately Ventilated Hospital Corridors
by Joan Truyols-Vives, Marta González-López, Antoni Colom-Fernández, Alexander Einschütz-López, Ernest Sala-Llinàs, Antonio Doménech-Sánchez, Herme García-Baldoví and Josep Mercader-Barceló
Toxics 2025, 13(7), 583; https://doi.org/10.3390/toxics13070583 - 12 Jul 2025
Viewed by 479
Abstract
Indoors, the infection risk of diseases transmitted through the airborne route is estimated from indoor carbon dioxide (CO2) levels. However, the approaches to assess this risk do not account for the airborne concentration of pathogens, among other limitations. In this study, [...] Read more.
Indoors, the infection risk of diseases transmitted through the airborne route is estimated from indoor carbon dioxide (CO2) levels. However, the approaches to assess this risk do not account for the airborne concentration of pathogens, among other limitations. In this study, we analyzed the relationship between airborne SARS-CoV-2 levels and environmental parameters. Bioaerosols were sampled (n = 40) in hospital corridors of two wards differing in the COVID-19 severity of the admitted patients. SARS-CoV-2 levels were quantified using droplet digital PCR. SARS-CoV-2 was detected in 60% of the total air samples. The ward where the mildly ill patients were admitted had a higher occupancy, transit of people in the corridor, and CO2 levels, but there were no significant differences in SARS-CoV-2 detection between wards. The mean CO2 concentration in the positive samples was 569 ± 35.6 ppm. Considering all samples, the CO2 levels in the corridor were positively correlated with patient door openings but inversely correlated with SARS-CoV-2 levels. In conclusion, airborne SARS-CoV-2 can be detected indoors with optimal ventilation, and its levels do not scale with CO2 concentration in hospital corridors. Therefore, CO2 assessment should not be interpreted as a surrogate of airborne viral presence in all indoor spaces. Full article
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13 pages, 2415 KiB  
Article
Thermophysiological Comfort Assessment of a Skirt Made from Bio-Based Material Derived from Pineapple Leaves
by Marija Pešić, Ineta Nemeša, Danka Đurđić and Dijamanta Salihi
Materials 2025, 18(14), 3249; https://doi.org/10.3390/ma18143249 - 10 Jul 2025
Viewed by 226
Abstract
The purpose of this paper is to evaluate the thermophysiological comfort of pineapple bio-based nonwoven material as a sustainable alternative to natural leather and synthetic polymer-coated materials by analyzing both the objective parameters of the material and subjective user feedback by wearing a [...] Read more.
The purpose of this paper is to evaluate the thermophysiological comfort of pineapple bio-based nonwoven material as a sustainable alternative to natural leather and synthetic polymer-coated materials by analyzing both the objective parameters of the material and subjective user feedback by wearing a skirt made from the same material. Considering the increasing demand for sustainable materials alternatives, the study aims to determine whether this material can offer acceptable comfort during wear. The research included two commercially available pineapple, bio-based, nonwoven materials that differed in their finishing. Sample S1 contained 5% Bio-PU and 5% conventional PU, and sample S2 contained 10% conventional PU. Objective parameters such as thermal resistance (Rct), water vapor resistance (Ret) and air permeability were measured. For the subjective evaluation, ten female subjects wore the pineapple bio-based material skirts under controlled environmental conditions. Sample S1 showed lower Rct values and slightly lower Ret combined with higher air permeability, which correlated with better subjective comfort evaluation. Although both samples showed high Ret values (S1 = 60.57 Pa2/W; S2 = 84.80 m2K/W) indicating limited vapor transfer, sample S1 was perceived as more comfortable, which was effected by better air permeability (S1 = 11.3 mm/s; S2 = 2.65 mm/s). Overall, S1 is more suitable for indoor use and for a shorter wear duration, while S2 may be better for cooler outdoor environments. Full article
(This article belongs to the Special Issue Leather, Textiles and Bio-Based Materials)
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14 pages, 2494 KiB  
Article
Colour Homogenisation and Photostability of Beech Wood (Fagus sylvatica L.) as Affected by Mild Steaming and Light-Induced Natural Ageing
by Zuzana Vidholdová, Gabriela Slabejová and Eva Výbohová
Forests 2025, 16(7), 1104; https://doi.org/10.3390/f16071104 - 4 Jul 2025
Viewed by 259
Abstract
This study investigates the impact of mild steaming (105 °C and 120 °C for 12 h) on the colour characteristics and chemical stability of beech wood (Fagus sylvatica L.) during natural indoor ageing. Untreated and steamed samples of mature wood and false [...] Read more.
This study investigates the impact of mild steaming (105 °C and 120 °C for 12 h) on the colour characteristics and chemical stability of beech wood (Fagus sylvatica L.) during natural indoor ageing. Untreated and steamed samples of mature wood and false heartwood were analysed for CIELAB and CIELCh colour parameters (L*, a*, b*, C*, h°) and chemical changes using ATR-FTIR spectroscopy. Steaming resulted in a significant decrease in lightness (L*) and increased a*, b*, and C* values, producing darker and more saturated reddish-brown tones. It also reduced the visual differences between mature wood and false heartwood, enhancing colour uniformity. During the light-induced ageing period, steamed wood—particularly at 105 °C—exhibited improved colour stability, maintaining chroma and hue more effectively than untreated samples. Statistically significant interaction effects between treatment, time, and tissue type revealed that the ageing-related colour changes were jointly influenced by thermal modification and the anatomical characteristics of the wood. In the FTIR spectra, the most pronounced changes were observed in the absorption bands of the aromatic skeleton and carbonyl groups (1504 and 1732 cm−1). These findings confirm that mild steaming alters the original aesthetic properties and colour of beech wood when exposed to an indoor environment. Full article
(This article belongs to the Special Issue Phenomenon of Wood Colour)
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12 pages, 971 KiB  
Article
Detection of Microbial Growth on Indoor Building Materials in Two Countries Using qPCR
by Helena Rintala, Oliver Röhl, Pinja Tegelberg and Teija Meklin
Microorganisms 2025, 13(7), 1551; https://doi.org/10.3390/microorganisms13071551 - 1 Jul 2025
Viewed by 277
Abstract
According to several reports, 10–50% of buildings in Europe and worldwide suffer from moisture problems, which can lead to microbial growth in building materials. Unrepaired moisture and microbial damage can lead to the degradation of building structures and reduce visual appeal, resulting in [...] Read more.
According to several reports, 10–50% of buildings in Europe and worldwide suffer from moisture problems, which can lead to microbial growth in building materials. Unrepaired moisture and microbial damage can lead to the degradation of building structures and reduce visual appeal, resulting in economic losses; they can also result in adverse health effects for the building’s occupants. Consequently, robust and reliable methods for the detection of abnormal microbiological conditions in buildings are needed, alongside skilled technical investigations, to plan appropriate renovation actions. In this work, 964 building material samples, which were obtained as part of routine building investigations in two countries, were analyzed for their fungal content using the qPCR method. Cultivation analysis was performed using the same samples, according to corresponding national guidelines. In a sample subset, the total cell counts after staining with acridine orange were determined. The microbial concentrations obtained with all three methods correlated well. Threshold values for the qPCR results were determined using cultivation as a reference method for both countries separately, with similar values obtained for both datasets. Hence, qPCR has great potential to become a standard method of detecting microbes in indoor environments. Full article
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12 pages, 218 KiB  
Article
COVID-19-Related Beliefs and Dietary Behaviors of American Undergraduate Students Vary by Race via the Lens of the Health Belief Model
by Doreen Liou and Jong Min Lee
COVID 2025, 5(7), 102; https://doi.org/10.3390/covid5070102 - 1 Jul 2025
Viewed by 243
Abstract
The COVID-19 pandemic caused immense physical disruptions, affecting young adults in the U.S. The Health Belief Model is a social psychological framework that predicts the likelihood of adopting health behavior. The purpose of this research is to investigate COVID-19-related health beliefs and dietary [...] Read more.
The COVID-19 pandemic caused immense physical disruptions, affecting young adults in the U.S. The Health Belief Model is a social psychological framework that predicts the likelihood of adopting health behavior. The purpose of this research is to investigate COVID-19-related health beliefs and dietary behaviors among undergraduate students during the pandemic. Using convenience sampling, a cross-sectional survey was completed by 304 individuals at a New Jersey state university. Survey data included the frequency of COVID-19 prevention behaviors (e.g., wearing an indoor mask, handwashing), and consumption of fruit and vegetables. The Health Belief Model constructs measured perceived susceptibility to COVID-19, severity, benefits, barriers, and self-efficacy. Frequency distributions, t-tests, and Kruskal–Wallis tests were investigated for racial subgroups (Whites, Blacks, Latinos, and Asians). The mean age of the sample was 21.7, with 27% males, and 46% self-identified as White. Whites adopted fewer COVID-19 prevention behaviors (p < 0.001) than non-Whites. Black students perceived less COVID-19 severity (p < 0.01) and stronger perceived benefits (p < 0.05) than the other subgroups. Latino students perceived greater susceptibility (p < 0.01) and greater barriers than non-Latinos. Asians practiced higher mask wearing frequency (p < 0.05) but less daily fruit intake than their counterparts (p < 0.01). This research highlights the importance of handwashing, wearing indoor masks, and consuming produce among university students. Addressing barriers to health action while promoting the benefits of enacting behaviors to mitigate the risk of COVID-19 is warranted. Full article
(This article belongs to the Section COVID Public Health and Epidemiology)
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