Color Alteration Research Articles

Influence of using different toothpaste during bleaching with violet LED light (405nm) on the colour and roughness of dental enamel: an in vitro study.

This in vitro study aimed to investigate potential changes in the color and roughness of dental enamel resulting from the use of different toothpaste formulations during bleaching with violet LED light (405nm). Sixty specimens of bovine incisors, each measuring 6 × 6 × 3mm, were segregated into six distinct experimental groups based on their respective treatments (n = 10): C + VL: Brushing with Colgate® Total 12 + bleaching with violet LED; LB + VL: Brushing with Colgate® Luminous White Brilliant + bleaching with violet LED; LI + VL: Brushing with Colgate® Luminous White Instant + violet LED bleaching; C: Brushing with Colgate® Total 12; LB: Brushing with Colgate® Luminous White Brilliant; LI: Brushing with Colgate® Luminous White Instant. The examined variables included alterations in color (∆L*, ∆a*, ∆b*, ∆Eab, and ∆E00), surface roughness (Ra), and scanning electron microscopy observations. No statistically significant distinctions emerged in total color variations (∆E00 and ∆E) among the groups under scrutiny. Notably, the groups that employed Colgate® Luminous White Instant displayed elevated roughness values, irrespective of their association with violet LED, as corroborated by scanning electron microscopy examinations. It can be concluded that whitening toothpastes associated to violet LED do not influence the color change of dental enamel in fifteen days of treatment. Toothpastes with a higher number of abrasive particles showed greater changes in enamel roughness, regardless of the use of violet LED.

Self-Assembled Plasmonic Structural Color Colorimetric Sensor for Smartphone-Based Point-Of-Care Ammonia Detection in Water.

Monitoring chemical levels is crucial for safeguarding both the environment and public health. Elevated levels of ammonia, for instance, can harm both humans and aquatic ecosystems, often indicating contamination from agriculture, industry, or sewage. Developing portable, high-resolution, and affordable methods for in situ monitoring of ammonia is thus imperative. Plasmonic sensors offer a promising solution, detecting ammonia by correlating changes in their optical response to the target analyte's concentration. While they are highly sensitive and can be fabricated in a variety of portable and user-friendly formats, some still require reagents or expensive optical equipment, which hinder their widespread adoption. Here, we present a self-assembled nanoplasmonic colorimetric sensor capable of directly detecting ammonia concentrations in aqueous matrices. The proposed sensor exploits the plasmonic resonance of the nanostructures to transduce changes in the chemical environment into alterations in color, offering a label-free method for real-time analysis. The sensor is fabricated using a self-assembling technique compatible with low-cost mass production based on aluminum and aluminum oxide, ensuring affordability and avoiding the use of other toxic chemicals. We developed a model to predict ammonia concentrations based on visible color change of the sensor, achieving a detection limit of 8.5 ppm. Furthermore, to address the need for on-site detection, we integrated smartphone technology for real-time color change analysis, eliminating the need for expensive, bulky optical instruments. Indeed, our approach offers a cost-effective, portable, and user-friendly solution for ammonia detection in water without the need for chemical reagents or spectrometers, making it ideal for field applications. Interestingly, this platform extends its applicability beyond ammonia detection, enabling the monitoring of various chemicals using a smartphone, without the need for any additional costly equipment.

The color stability of artificial white spot lesions treated with resin infiltration after exposure to staining beverages

BackgroundTo evaluate the effect of staining beverages on the color-changing of resin-infiltrated artificial white spot lesions (WSLs).MethodsThirty-five artificial WSLs were created by pH cycling on flat bovine teeth specimens. The WSLs were treated with resin infiltration and were divided into five groups based on staining beverages: artificial saliva, coffee, wine, green tea, and Coca-Cola. These specimens were subjected to a 28-day exposure to the respective beverages. Color stability was assessed using a spectrophotometer at different time points: baseline, after 7, 14, 21, and 28 days of exposure, and repolishing. The color difference (∆E) between each time point and the baseline was calculated. Statistical analysis was performed using two-way measures ANOVA with a significance level of p = 0.05.ResultsAll resin-infiltrated specimens exposed to staining beverages for 7 days exhibited more significant color changes than those exposed to artificial saliva. The color change patterns varied based on the type of beverage. The color alterations intensified with extended immersion in the wine and Coca-Cola groups, while there were no significant differences in the color of specimens after 28 days of immersion in the coffee and green tea groups. However, after cleaning with pumice powder, all specimens showed significantly reduced color changes compared to those observed after 28 days of immersion, except those immersed in coffee.ConclusionsExposure of resin-infiltrated bovine tooth specimens to staining beverages resulted in a significant color alteration as the immersion time increased. However, the staining effect could be minimized by cleaning with pumice powder, except for the coffee group.Clinical relevanceAfter resin infiltration treatment, patients should be advised to minimize the consumption of colored beverages to prevent staining that could impact esthetic appearance.

Are physical and mechanical properties of 3D resins dependent on the manufacturing method?

This research analyzed the effect of the manufacturing method on the flexural strength and color stability of 3D-printed resins used for producing indirect restorations. For this, two dental restorative biocompatible resin materials, OnX (OnX, SprintRay) and CB (Crown and Bridge, Dentca), were divided into 2 groups according with manufacturing method (printed with a Pro95 3D printer - SprintRay; and not printed, with samples obtained with the fluid resin being poured on PVS molds for further light activation in the post-curing process), and subdivided into 2 groups according to the post-curing method: VG (Valo Grand, Ultradent Products) for 120s and PC (Procure 2, SprintRay). Bar-shaped samples were used to evaluate the flexural strength 24h after storage in distilled water at 37°C using a universal testing machine. Disk-shaped samples were used to evaluate the color stability with a spectrophotometer at baseline, after 1-7days in dark dry storage at 37°C, and after 1day of artificial aging in water at 60°C. Data were evaluated using 3-way ANOVA (flexural strength) and 4-way repeated measures ANOVA (color stability), followed by the Tukey's HSD test (α = .05). Flexural strength showed significant results for resin (p < .001), while manufacturing and post-curing methods were not significant (p > .05). The interaction effects between resin and manufacturing method (p = .978), and between resin, manufacturing method and post-curing method (p = .659) were not significant. In general, OnX showed higher flexural strength values than CB, regardless of manufacturing method or post-curing protocol. Color stability results showed significant results for resin (p < .001), time (p < .001), resin and time (p = .029), and resin and curing method (p < .001), but no differences considering resin and manufacturing mode (p = .87), or resin, manufacturing method and curing method (p = .35). In general, OnX showed a higher color change than CB, longer storage times resulted in increased color change for both materials, and CB cured with VG showed lower color alteration than CB cured with PC2. The manufacturing method (3D printed or not 3D printed) does not seem to influence the flexural strength and color stability of 3D printed resins. This may indicate that, at least from a physical-mechanical perspective, the final properties of the material are mainly dependent on the post-curing process.

Tomato Recognition Method Based on the YOLOv8-Tomato Model in Complex Greenhouse Environments

Tomatoes are a critical economic crop. The realization of tomato harvesting automation is of great significance in solving the labor shortage and improving the efficiency of the current harvesting operation. Accurate recognition of fruits is the key to realizing automated harvesting. Harvesting fruit at optimum ripeness ensures the highest nutrient content, flavor and market value levels, thus maximizing economic benefits. Owing to foliage and non-target fruits obstructing target fruits, as well as the alteration in color due to light, there is currently a low recognition rate and missed detection. We take the greenhouse tomato as the object of research. This paper proposes a tomato recognition model based on the improved YOLOv8 architecture to adapt to detecting tomato fruits in complex situations. First, to improve the model’s sensitivity to local features, we introduced an LSKA (Large Separable Kernel Attention) attention mechanism to aggregate feature information from different locations for better feature extraction. Secondly, to provide a higher quality upsampling effect, the ultra-lightweight and efficient dynamic upsampler Dysample (an ultra-lightweight and efficient dynamic upsampler) replaced the traditional nearest neighbor interpolation methods, which improves the overall performance of YOLOv8. Subsequently, the Inner-IoU function replaced the original CIoU loss function to hasten bounding box regression and raise model detection performance. Finally, the model test comparison was conducted on the self-built dataset, and the test results show that the mAP0.5 of the YOLOv8-Tomato model reached 99.4% and the recall rate reached 99.0%, which exceeds the original YOLOv8 model detection effect. Compared with faster R-CNN, SSD, YOLOv3-tiny, YOLOv5, and YOLOv8 models, the average accuracy is 7.5%, 11.6%, 8.6%, 3.3%, and 0.6% higher, respectively. This study demonstrates the model’s capacity to efficiently and accurately recognize tomatoes in unstructured growing environments, providing a technical reference for automated tomato harvesting.

Traffic lights inspired colorimetric sensing platform for cadmium/lead ions: PO43- induced structural change of porphyrin metal-organic framework

Developing rapid and user-friendly visual techniques for distinguishing and identifying heavy metal ions is a critical pursuit in food and environmental analysis. In this work, a zirconium-based metal organic framework (MOF) known as PCN-222 has been synthesized, serving as a colorimetric nanoplatform for the differentiation and detection of Cd2+ and Pb2+ in the presence of PO43-. The remarkable characteristic of PCN-222 stems from its reaction with PO43-, where the robust bonding between PO43- and Zr nodes triggers the collapses of PCN-222, leading to the release of ligands (TCPP) with visible alteration in solution color to light red. When exposure to Cd2+ and Pb2+, shifts to green and yellow, respectively, are discernible. These changes can be ascribed to differences in the size, atomic configuration, and electronegativity of the two metal ions, which impact their interaction with TCPP. The innovative concept of a nanomaterial traffic light is introduced based on these color transitions. Accurate quantification of Cd2+ and Pb2+ can be efficiently accomplished both individually and concurrently using UV spectroscopy and a mobile phone APP, providing adaptability in method selection depending on on-site conditions. Moreover, the platform effectively tackles selectivity challenges associated with ligand-based detection methods, showcasing high sensitivity, distinct visual indications, and simplicity in instrumentation requirements.

The impact of mental health and psychological stressors on menstrual cycle modulation: exploring the influence of age and hormonal contraceptives.

The objective of this study was to analyze the influence of a stressor, a period of the Covid-19 pandemic when there were no vaccines available yet, on the psychological state of women aged 18 to 45 years; as well as the influence of mental health on the menstrual cycle, considering the influence of age and hormonal contraceptives. Online questionnaire using the Google Forms platform was used. There is a high prevalence of the onset of new psychosocial symptoms. Moreover, most women reported some type of change in their menstrual cycles. The women who were using hormonal contraceptives demonstrated a higher frequency of spotting and menstrual color alterations, while women without hormonal contraceptives demonstrated a higher frequency of cycle duration and menstrual odor alterations. Women without hormonal contraceptives were more susceptible to the development of psychosocial symptoms. Younger adult women were more affected by menstrual changes and psychosocial symptoms. Close to 90% of women who reported several psychosocial symptoms had changes in their menstrual cycles. These data suggest the impact of stressors, such as a period of the pandemic, on mental health and menstrual cycles, and younger adult women can be more susceptible. This reflects the relationship between mental and reproductive health.

Evaluating the Effects of Cigarette Smoking and Heated Tobacco Products on Hard Dental Tissues: A Comparative Histological and Colorimetric Analysis.

This study aimed to evaluate and compare the impact of cigarette smoking (CS) and heated tobacco (HT) on the alteration of color and ultrastructural characteristics of human enamel and cementum. According to tobacco companies, a less harmful substitute for CS is HT products. Nevertheless, comprehensive research on the effects of HT on tooth structures has been lacking. This study aimed to evaluate and compare the impact of CS and HT on the alteration of color and ultrastructural characteristics of human enamel and cementum. Thirty intact and noncarious human maxillary premolars extracted for orthodontic treatment purposes, previously disinfected, were used in the study. The specimens were randomly separated into six groups (n = 10), as follows: Group 1: enamel without smoking exposure; Group 2: enamel exposed to CS; Group 3: enamel exposed to HT; Group 4: cementum without smoking exposure; Group 5: cementum exposed to CS; and Group 6: cementum exposed to HT. The measurement of color change was conducted using a spectrophotometer. The surface alterations and mineral composition of enamel and cementum were evaluated using scanning electron microscopy and energy-dispersive X-ray spectroscopy. ANOVA test followed by Tukey's post hoc test was used to determine significant differences between groups. Results showed that CS had a more pronounced effect on enamel and cementum color changes than HT. The impact of CS and HT on color changes was more evident in cementum than in enamel. Surface morphology of enamel and cementum showed alterations in histology following exposure to both smoking types. Moreover, the mineral content experienced a significant reduction after using CS and HT. The reduction in calcium content after CS and HT exposure was similar. However, HT led to a significant decrease in the phosphorus content of enamel when compared with CS. At the same time, CS exposure in cementum resulted in a more significant reduction in Ca/P ratio than HT. Although HT may appear to present a lower danger to hard dental tissues than CS, it is not entirely harmless. CS results in more color changes on the enamel and cementum of teeth. Both smoking methods affected the mineral content of teeth, with CS having a significant effect on the roots, while HT significantly affected the crowns' mineral composition.

Utilization of Butterfly Pea Flower as Shelf-Life Colour Indicator for Keropok Lekor Smart Packaging

Studying the feasibility of using Clitoria ternatea or butterfly pea extract (BPE) as a colorimetric indicator to determine the shelf life of Keropok Lekor would aid in monitoring storage conditions, emphasizing its potential contribution to the smart packaging industry. The objective of this research is to develop pH-sensitive packaging using gelatine film infused with butterfly pea extract (BPE) along with ultrasonic-assisted extraction methods. The investigation involves quantifying the physicochemical attributes of the extracted butterfly pea and ascertaining the colour alterations during the storage of Keropok Lekor over a duration of six days. The determination of total anthocyanin content in BPE, conducted through a pH differential assay, yielded a value of 1.08 mg/g. Texture analysis revealed that the film with 10% BPE exhibited elevated tensile strength (0.11±0.01) and toughness (0.03±0.01). Total phenolic compound analysis indicated that the film containing 30% BPE possessed the highest value at 0.16±0.02. Notably, the film with 30% BPE demonstrated the highest colour change in Keropok Lekor storage from dark blue (-22.5±80.95) to dark green (6.34±1.85) over the course of six days. The film incorporated with 30% BPE stands as a viable colour indicator, demonstrating the potential for monitoring the freshness and quality of Keropok Lekor.

Effect of chitosan of milkfish scale waste (Chanos chanos) on the preservation of tomato fruit (Lycopersium esculentum)

Tomatoes (Lycopersium esculentum) provide excellent nutritional value for human health. However, their high water content and classification as climacteric fruits, which undergo quick ripening through respiration, make them vulnerable to harm during the post-harvest period. One method employed to prolong the longevity of tomatoes involves the application of a coating made from chitosan derived from milkfish scales. The objective of this study is to assess the impact of chitosan derived from milkfish scales (Chanos chanos) on the longevity of tomatoes by examining alterations in color, weight loss, pH level (acidity), and vitamin C content. This study employs a complete random design (CRD) experiment consisting of five treatments: P0 = 0%, P1 = 1%, P2 = 1.5%, P3 = 2%, and P4 = 2.5%. Each treatment is replicated three times. The metrics recorded encompassed the tomato's color, weight loss measured by comparing the initial weight with subsequent weights, pH value (indicating acidity), and monitoring of vitamin C levels.

Microplastics meet micropollutants in a central european river stream: Adsorption of pollutants to microplastics under environmentally relevant conditions

Microplastics have emerged as pervasive pollutants in aquatic environments, and their interaction with organic contaminants poses a significant environmental challenge. This study aimed to explore the adsorption of micropollutants onto microplastics in a river, examining different plastic materials and the effect of aging on adsorption capacity. Microplastics (low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC)) were introduced into a river stream, and a comprehensive analysis involving 297 organic pollutants was conducted. Passive samplers were deployed to monitor micropollutant presence in the river. Sixty-four analytes were identified in the river flow, with telmisartan being the most prevalent. Nonaged PVC showed the highest telmisartan concentration at 279 ng/g (168 ng/m2 regarding the microplastic surface), while aged PVC exhibited a fourfold decrease. Conversely, aged LDPE preferentially adsorbed metoprolol and tramadol, with concentrations increasing 12- and 3-fold, respectively, compared to nonaged LDPE. Azithromycin and clarithromycin, positively charged compounds, exhibited higher sorption to PET microplastics, regardless of aging. Diclofenac showed higher concentrations on nonaged PVC compared to aged PVC. Aging induced structural changes in microplastics, including color alterations, smaller particle production, and increased specific surface area. These changes influenced micropollutant adsorption, with hydrophobicity, dissociation constants, and the ionic form of pollutants being key factors. Aged microplastics generally showed different sorption properties. A comparison of microplastics and control sand particles indicated preferential micropollutant sorption to microplastics, underscoring their role as vectors for contaminant transport in aquatic ecosystems. Analysis of river sediment emphasized the significance of contact time in pollutant accumulation. Overall, this study provides insights into the complex interactions between microplastics and organic pollutants under environmental conditions and contributes to a better understanding of the fate and behavior of these two types of contaminants in aquatic ecosystems.

Color alterations in plumage of Strigidae: a new record for the Short-eared Owl (Asio flammeus) in Ecuador

Color alterations in plumage of Strigidae: a new record for the Short-eared Owl (Asio flammeus) in Ecuador

Colorimetric Analyses of the Optic Nerve Head and Retina Indicate Increased Blood Flow After Vitrectomy.

The purpose of this study was to evaluate the impact of vitrectomy and posterior hyaloid (PH) peeling on color alteration of optic nerve head (ONH) and retina as a surrogate biomarker of induced perfusion changes. Masked morphometric and colorimetric analyses were conducted on preoperative (<1month) and postoperative (<18months) color fundus photographs of 54 patients undergoing vitrectomy, either with (44) or without (10) PH peeling and 31 years of age and gender-matched control eyes. Images were calibrated according to the hue and saturation values of the parapapillary venous blood column. Chromatic spectra of the retinal pigment epithelium and choroid were subtracted to avoid color aberrations. Red, green, and blue (RGB) bit values over the ONH and retina were plotted within the constructed RGB color space to analyze vitrectomy-induced color shift. Vitrectomy-induced parapapillary vein caliber changes were also computed morphometrically. A significant post-vitrectomy red hue shift was noted on the ONH (37.1degrees ± 10.9degrees vs. 4.1degrees ± 17.7degrees, P < 0.001), which indicates a 2.8-fold increase in blood perfusion compared to control (2.6 ± 1.9 vs. 0.9 ± 1.8, P < 0.001). A significant post-vitrectomy increase in the retinal vein diameter was also noticed (6.8 ± 6.4% vs. 0.1 ± 0.3%, P < 0.001), which was more pronounced with PH peeling (7.9 ± 6.6% vs. 3.1 ± 4.2%, P = 0.002). Vitrectomy and PH peeling increase ONH and retinal blood flow. Colorimetric and morphometric analyses offer valuable insights for future artificial intelligence and deep learning applications in this field. The methodology described herein can easily be applied in different clinical settings and may enlighten the beneficial effects of vitrectomy in several retinal vascular diseases.

Colorimetric and ECL dual-mode aptasensor for smartphone-based onsite sensitive detection of aflatoxin B1 in combination with ZnO@MWCNTs/g-C3N4 nanosheets and CuO@CuPt nanocomposites

The development of dual-mode strategies with superior sensitivity and accuracy have garnered increasing attention for researchers in Aflatoxin B1 (AFB1) analysis. Herein, a colorimetric-electrochemiluminescence (ECL) dual-mode biosensor was constructed for onsite and ultrasensitive determination of AFB1. The multi-wall carbon nanotubes (MWCNTs) were integrated with the ZnO metal organic frameworks (MOFs) to accelerate the electron transfer and boost the ECL intensity of g-C3N4 nanoemitters. Through the aptamer-based DNA sandwich assay, the CuO@CuPt nanocomposites were introduced onto the electrode and acted as the dual functional signal nanoprobes. Due to the good spectrum overlap between the CuO@CuPt nanoprobes and g-C3N4 nanosheets, ECL signal could be efficiently quenched. Additionally, the CuO@CuPt nanoprobes show superior catalytic properties towards the TMB and H2O2 colorimetric reactions, and an obvious color alteration from colorless to blue can be observed using the smartphone. Under optimized conditions, a sensitive and accurate dual-mode analysis of the AFB1 was accomplished with the colorimetric detection limit of 3.26 fg/mL and ECL detection limit of 0.971 fg/mL (S/N = 3). This study combines innovative nanomaterial properties of ZnO@MWCNTs, g-C3N4 and CuO@CuPt for ultrasensitive dual-mode detection, which offers new opportunities for the innovative engineering of the dual-mode sensors and demonstrates significant potential in food safety analysis.

Ratiometric fluorescence and smartphone-assisted sensing platform based on dual-emission carbon dots for brilliant blue detection

In this study, an innovative ratiometric fluorescence and smartphone-assisted visual sensing platform based on blue-yellow dual-emission carbon dots (BY-CDs) was constructed for the first time to determine brilliant blue. The BY-CDs was synthesized via a facile one-step hydrothermal process involving propyl gallate and o-phenylenediamine. The synthesized BY-CDs exhibit favorable water solubility and exceptional fluorescence stability. Under excitation at 370 nm, BY-CDs show two distinguishable fluorescence emission bands (458 and 558 nm). Upon addition of brilliant blue, the fluorescence intensity at 558 nm exhibited a significant quenching effect attributed to fluorescence resonance energy transfer (FRET), while the fluorescence intensity at 458 nm was basically unchanged. The prepared BY-CDs can effectively serve as a ratiometric nanosensor for determining brilliant blue with the ratio of fluorescence intensities at 458 and 558 nm (F458/F558) as response signal. In addition, the developed ratiometric fluorescence sensor exhibits a noticeable alteration in color from yellow to green under UV light with a wavelength of 365 nm upon addition of varying concentrations of brilliant blue, which provides the possibility of visual detection of brilliant blue by a smartphone application. Finally, the BY-CDs based dual-mode sensing platform successfully detected brilliant blue in actual food samples and achieved a desirable recovery rate. This study highlights the merits of fast, convenient, economical, real-time, visual, high accuracy, excellent precision, good selectivity and high sensitivity for brilliant blue detection, and paves new paths for the monitoring of brilliant blue in real samples.

New records of birds with color alterations from Ecuador

We report six new cases of wild birds with chromatic aberration from four provinces of Ecuador. The photographic records come from opportunistic observations. This is the first record of aberrant plumage for Anas bahamensis, Florisuga mellivora, Opisthocomus hoazín, Dendrocincla fuliginosa y Asemospiza obscura; while cases of aberrant individuals are added in Turdus fuscater. The case of F. mellivora is the most relevant due to its rarity and evidence of coloration patterns in the species. We highlight the importance of documenting and publishing the encounter of these events.

Evaluation of Gingival Issues Encountered by Adults Receiving Fixed Orthodontic Treatment in Dakshina Kannada Population: A Questionnaire Study

Background: Fixed orthodontic components used in orthodontic treatment can serve as a focal point for plaque and biofilm accumulation, leading to plaque-associated gingivitis. This occurs due to the intricate interaction between the host (patient) and the microbial environment surrounding these components. Alterations in gingival color, shape, size, texture, and contour should serve as warning signs for both the patient and the orthodontist, prompting them to take preventive measures against further progression. It's crucial to educate both the orthodontist and the patient about the potential complications linked to the gingival response during treatment.  Methods: This Questionnaire study sample size of 150 was performed to evaluate the gingival problems faced by the patients undergoing fixed orthodontic therapy in Dakshina kannada population .  Results: Most individuals undergoing orthodontic treatment were typically in the age range of 19 to 24 years old. There was a higher proportion of female participants compared to males, and the majority of them maintained good oral hygiene. Young adults demonstrated greater awareness and understanding of the treatment, which contributed to improved gingival health outcomes.  Conclusion: The responsibility for maintaining oral health predominantly rests with the patient, who must ensure adherence to proper, effective, and thorough oral hygiene routines. It's imperative for every orthodontic patient to receive encouragement and education regarding the gingival changes associated with orthodontic treatment and the importance of maintaining good oral hygiene practices.

Localized Surface Plasmon Resonance (LSPR) of Nanomaterials for Colorimetric Detection: A Review

Colorimetric sensors are attracting considerable interest across diverse fields owing to their ease of use, cost-effectiveness, and rapidity. Within this realm, Localized Surface Plasmon Resonance (LSPR) stands out as a favorable method for designing colorimetric sensing techniques. Sensors based on LSPR control the plasmonic characteristics of metallic Nanoparticles (NPs) to produce a noticeable alteration in color when a target analyte is detected. This article explores recent advancements in this field, including the integration of LSPR sensors with microfluidics and smartphone-based detection systems. The paper also investigates the applications of LSPR-based colorimetric sensors in diverse domains, such as environmental monitoring, biomedical diagnostics, food safety, and chemical detection. Furthermore, it sheds light on the potential limitations and prospects associated with LSPR-based colorimetric sensors, with a particular emphasis on the need for improved sensitivity, selectivity, and stability to facilitate broader practical applications.

Prevalence and risk factors of cold intolerance in a tropical region: A population-based prevalence study

Cold intolerance is an abnormal reaction to cold exposure that results in pain and discomfort. It is predominantly characterized by pain/aching, numbness, tingling, color alteration, stiffness, swelling and loss of function. The aim of this study was to determine the prevalence of cold sensitivity in the city of Kashan, which has a warm climate, and compare it with the prevalence of cold sensitivity in colder regions. In this cross-sectional study, cold-related symptoms and cold intolerance (CISS ≥ 50) were reported in 78 (25.2%) and 16 (5.2%) persons, respectively. We compared the demographic and clinical characteristics of participants with and without cold intolerance. There was no significant difference between the participants with and without cold intolerance in terms of age and body mass index. The frequency of cold intolerance was higher in smokers and participants with comorbidity, although it did not reach a significant level.

Potensi Antibakteri Minuman Fungsional Tradisional Jawa (Wedang Uwuh) Berdasarkan Variasi Waktu Rebusan

Wedang uwuh is a functional beverage prepared by boiling a combination of spices, namely sappan wood, ginger, nutmeg leaves, cinnamon leaves, cloves, and clove leaves. It is reported to have antioxidant, antibacterial, and immune-enhancing properties due to its active compounds. This traditional beverage shows potential in reducing infections caused by Escherichia coli, highlighting the importance of proper preparation methods. The objective of this study was to evaluate the antibacterial activity of wedang uwuh prepared by different boiling duration (5, 10, 15, and 20 min) to determine the optimal time for maximum effectiveness. Phytochemical changes, as indicated by color alterations, were assessed by a descriptive approach while a disc diffusion method was used as an antibacterial assay to measure the inhibition zone diameter against E. coli. Compounds in each treatment were analyzed using GC-MS. Phytochemical screening confirmed the presence of alkaloids, flavonoids, saponins, triterpenoids, and tannins in all variations. Antibacterial testing revealed that boiling for 15 min exhibited the highest activity, with an inhibition zone diameter of 10.43±1.33 mm, reflecting strong antibacterial efficacy. This result significantly differed from the 5 and 10 min treatments. The 5 min boiling treatment demonstrated a smaller inhibition zone with an average diameter of 5.71±1.67 mm, indicating moderate antibacterial activity, but it did not differ significantly from the 10 min treatment. A chemical analysis by GC-MS for the 15 min boiling sample successfully identified 23 compounds, and among these chemicals, hexadecanoic acid was found as the predominant component.