Change In Color Research Articles

Exploring sterilizer performance through external biological indicator testing: a retrospective study

BackgroundQuality assurance policies mitigate the risk of nosocomial infections from dental office instrument sterilization by assessing sterilizer performance through biological indicator (BIs) testing. This study aimed to evaluate the prevalence of failed sterilization cycles and their causes of failure for a period of eight years through database analysis of a quality assurance laboratory in the province of Saskatchewan, Canada.MethodsA database of BIs (n = 198,771) performed by an independent quality assurance laboratory from 2015 to 2022 was analyzed. Dental offices (n = 362) inserted Sporview® Biological Sterility Indicators strips in full sterilizer loads and mailed the processed BI tests to an external quality assurance laboratory for analysis. Samples were assessed based on a colorimetric method checking for changes in color and turbidity. Data was collected and statistical analyses were performed using IBM SPSS 28.0.ResultsThe overall failure rate throughout the study was 0.20%, and it decreased gradually from 0.51% (2015) to 0.15% (2022). On average, retests were conducted within 2 days of failure notification. The preferred method of processing was steam sterilization (98%), which had a steadily increasing utilization over time and displays a statistically lower failure rate (0.20%) as opposed to dry heat (1.30%) and chemical vapour (1.40%) sterilizers. Most BI failures were attributable to human error (91.80%), and equipment failures were significantly more likely to occur with dry heat or chemical vapour sterilizers (p < .001).ConclusionThis study significantly contributes to the understanding of dental sterilizer performance in Canada. The low and decreasing sterilizer failure rates over the study period indicate safe dental office procedures and reduced potential for disease transmissions. The study highlights the effectiveness of steam sterilizers with remarkably low failure rates, while human error remains the primary cause of failures. Further research should focus on identifying factors leading to human error and interventions to minimize sterilization failures in dental settings.

Biocomposites Based on Polyethylene/Ethylene–Vinyl Acetate Copolymer/Cellulosic Fillers

This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties.

Neoplasias mamária e esplênica em cadela

Regarding mammary and splenic neoplasms in dogs, the surgical therapeutic approach is often the method of choice, given its curative potential and the possibility of subsequent histopathological analysis. In veterinary medicine, the incidence of mammary neoplasms is high, especially in unneutered female dogs. Breast carcinoma in situ, with its histological particularities and clinical behavior, requires a careful diagnosis and a precise therapeutic approach, carrying out additional tests such as cytopathology and ultrasound to adequately define the treatment. Surgical excision, associated with the evaluation of adjacent healthy breast tissue, is essential to ensure complete removal of neoplastic tissue, plus it is also indicated to perform ovariohysterectomy (OVH) together with mastectomy. Spleen tumors are similarly common in dogs, especially hemangiosarcoma, which is notable for its aggressiveness and high metastatic rate. Therefore, early diagnosis and precise interventions are essential for a good prognosis, with the affected organ being often removed in its entirety. Therefore, we report the case of a female Shih-Tzu dog, 7 years old and weighing 4kg, who presented, upon palpation, a nodule in the left M3 measuring &lt;1cm with absence of nodular secretion, change in color, itching local or galactorrhea. The patient was referred for regional mastectomy and OVH after cytological examination compatible with carcinoma and, in a pre-operative ultrasound examination, a singular hypoechoic nodular formation, discretely heterogeneous, vascularized on Doppler and in close contact with the splenic capsule was noted in the spleen in its medial parietal portion, measuring 0.96 cm in its longest axis. Thus, during intraoperative visual inspection after OVH and upon approval from the owner, it was decided to perform total splenectomy and, after histopathological examination, it was known that the organ was affected by hemangiosarcoma. The canine was discharged from the hospital a few hours after the end of the surgery, without the subsequent use of adjuvant therapies.

A clinical approach for no prep direct composite veneers with opaquer/ tint to reshape a smile: a case report

Dental aesthetic has a profound influence on both self-esteem and social interactions. Patients desire changes in their smiles, while dentists aim for the preservation of dental and adjacent structures, as well as durability. In this context, no-prep resin veneers emerge as a potential solution, as they allow for the preservation of the maximum amount of healthy dental structure, pulp integrity, and dental strength. Nevertheless, treating darkened substrates poses a challenge, and conservative options like composite resins have gained recognition as restorative materials due to their aesthetic qualities and ability to preserve healthy dental tissue. A protocol can help dentists, especially by describing the stages of making direct no-prep veneers, achieving better clinical success. This article presents a clinical step-by-step guide approach to fabricating light-cured composite prepless veneers, using opaque and tints to mask dark backgrounds, and preserving the dental substrate in a patient with multiple restorations, changes in color, and shape. Light-cured composite prepless veneers comply with the principles of biomimetics and offer advantages such as conservation of dental structures, versatility, one-session preparation, cost, mechanical properties, and excellent aesthetics, however, skill with this technique is required.

DFT molecular modeling investigation and optical properties characterization of CR-39 films

Abstract In this study, the structural and optical characteristics of CR-39 films were investigated both theoretically and experimentally. A number of parameters for the CR-39 structure were theoretically computed by the density functional theory (DFT) method at B3LYP/6–311 G (p, d) level of theory. FTIR and UV/Vis spectroscopy were used to determine the structure compositions and the optical parameters of the CR39 film, respectively. The computed and experimental findings show good concordance. It was found that the CR-39 compound’s total energy, dipole moment, and energy difference between the LUMO and HOMO were, respectively, −994.575 a.u., 2.772 Debye, and 7.045 eV. The MEP showed a progressive change in color, with blue signifying a low electron density and red denoting a high electron density linked to nucleophilic reactivity and electrophilic reactivity. Further, the positive charges on all hydrogen atoms, which range from 0.16506 to 0.22032 a.u., imply that they are acceptors. The positive H34 is strongly produced when electrons from the negatively charged C17 are taken up. Because they are donor atoms, part of the carbon atoms in the structure is negative, while the other atoms are positive. The highest electronegative atoms H23 and H24 were substituted, resulting in the extremely negative carbon atom C7 (−0.32436). According to the experimentally determined absorption coefficient and energy gap values, CR-39 films may find application in optoelectronic devices.

Green Synthesis of Platinum Nanoparticle Using Lemon (Citrus Limon) Peel Extract and its Characterization

Green synthesis of platinum nanoparticle using lemon peel extract is an alternative way to chemical synthesis of nanoparticles. This research was designed for the environmental friendly, pollution free, cost effective and has no side effects to the environment. The platinum nanoparticle was synthesized using (Citrus limon) lemon peel extract. Parameters such as time, pH, concentration, temperature and change in color from yellow to yellowish brown indicates the reduction of platinum ions which confirmed the synthesized platinum nanoparticle. The green synthesized platinum nanoparticle was further characterized by UV visible spectroscopy, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction Spectroscopy (XRD). The results of the UV spectroscopy revealed the reduction of platinum ions to platinum nanoparticle at the peak of 344 nm. The results of the Scanning Electron Microscopy confirmed the morphology of platinum nanoparticle which were smooth and spherical with a diameter of range from 71 to 90 nm at 41.0 kx magnification. The results of the Fourier Transform Infrared Spectroscopy revealed the strong broad band between 1095 to 3244.00 cm-1 which confirmed the presence of functional groups. X- ray diffraction (XRD) analysis confirmed the crystalline structure of synthesized platinum nanoparticle with the distinct peaks at 39.0°, 46.3° and 67.5°. Therefore the green synthesized platinum nanoparticle is an advantage to the environment than the chemical approaches. This technique is efficient and holds potential for various industrial applications and is sustainable.

Glycation of sunnhemp protein with dextran via dry heating: Thermal, micro-structural characterization, and amino acid profiling.

This study aims to obtain sunnhemp protein isolate (SHPI) and dextran conjugates by dry heating method of Maillard conjugation. The effects of different incubation time (0, 1, 3, 5, 7, and 9 days) on the molecular flexibility, available lysine content, antioxidant properties, molecular structure, and thermal and micro-structural properties of conjugates were compared with SHPI (no conjugation) at 60°C and 79% relative humidity. The results indicated the formation of SHPI-dextran conjugates as confirmed by the change in molecular flexibility, lysine content, antioxidant activities, color, and water activity values. The molecular structure revealed the confirmation of covalent bonding between SHPI and dextran. Differential scanning calorimetry and thermo-gravimetric analysis results exhibited improvement in the thermal stability of SHPI when conjugated with dextran. The microstructural characterization showed that Maillard conjugation changed the surface structure of SHPI. The analysis of amino acid composition displayed that lysine, arginine, and phenylalanine were the dominant Maillard reaction sites of SHPI and dextran. Among all the conjugated samples, 5 days of incubation time was selected as an optimum condition for the development of SHPI-dextran conjugates on the basis of the aforementioned characterization. Overall, it was concluded that Maillard conjugation of sunnhemp protein with dextran via dry-heating technique could modify and improve its various attributes. PRACTICAL APPLICATION: The conjugation of plant proteins with polysaccharide through the Maillard reaction under dry heating conditions represents a natural and green technique for improving the techno-functional properties of proteins. The study has the potential to establish framework for the utilization of Sunnhemp protein isolate-dextran conjugates. This approach offers the potential for cost-effective production of emulsifiers and development of effective encapsulating matrices. The investigation expands on an underutilized plant protein source facilitating an alternative to animal-based proteins and contributing to the development of a sustainable circular bioeconomy.

SWATH-MS based proteomics reveals the role of photosynthesis related proteins and secondary metabolic pathways in the colored leaves of sweet olive (Osmanthus fragrans)

Colored leaves, a notable horticultural trait, have high research and ornamental value. The evergreen sweet olive (Osmanthus fragrans), one of the top ten traditional flowers in China, has been cultivated for more than two thousand years. However, in recent years, an increasing number of O. fragrans cultivars with colored leaves have been cultivated for their ornamental value. To study the molecular mechanism underlying the observed changes in leaf color, we selected O. fragrans ‘Yinbi Shuanghui’ (Y), which has yellow-white leaves, and O. fragrans ‘Sijigui’ (S), which has green leaves, as materials. Pigment content measurement showed that the chlorophyll, carotenoid and anthocyanin contents in Y were lower than in S. According to the SWATH-MS sequencing results, a total of 3,959 proteins were quantitatively identified, 1,300 of which were differentially expressed proteins (DEPs), including 782 up-regulated and 518 down-regulated proteins in Y compared to S. Functional enrichment analysis of DEPs revealed that down-regulated expression of photosynthesis related proteins may lead to the inhibition of chlorophyll synthesis in Y, this may be the main cause of leaf color change. Moreover, a protein interaction prediction model also showed that proteins such as PetC, PsbO, PsbP, and PsbQ were key proteins in the interaction network, and the up-regulated proteins participating in the anthocyanin and carotenoid pathways may be related to the formation of yellow-white leaves. Taken together, our findings represent the first SWATH-MS-based proteomic report on colored leaf O. fragrans and reveal that chlorophyll synthesis and secondary metabolism pathways contribute to the changes in leaf color.

Temporal analysis of non-targeted flavor component variation in green tea storage and rapid prediction of storage duration

The precise changes in the flavor quality of green tea before and after the optimal consumption period remain elusive. This study used HS-SPME-GC–MS to carefully examine the volatile compounds of new tea and multiple green tea samples stored for optimal taste periods and simultaneously detected changes in taste and color during tea infusion. Notably, 16 compounds with VIP > 1.5 were identified, highlighting their significance in the overall analysis profile. Among these components, nonanoic acid, octanoic acid and hexanal were identified as potential contributors to off-flavors and rancid oil flavors in tea after storage. The color of the tea broth becomes darker. Bitter flavor is associated with increased amino acid content. The PSO-SVM model showed excellent accuracy for predicting the storage duration of green tea. These findings provide critical theoretical understandings of green tea manufacturing and quality control.

Reproductive Aspects of Blue Swimming Crab (Portunus pelagicus) Landed on the South End Coast of East Lombok

This study aims to describe aspects of the reproductive biology of a blue swimming crab (Portunus pelagicus) that landed at the southern end of the coast of East Lombok during the period November 2023 to April 2024. The study used a descriptive design with a quantitative approach to measure and analyze data through direct observation. Data included carapace width, body weight, gonad maturity stages, and gonad somatic index (GSI) of P.pelagicus. The results showed that the male P.pelagicus population was more dominant than females every month. P.pelagicus body weight varied, with significant increases in certain months caused by spawning. Analysis of the relationship between carapace width and body weight showed positive allometric growth, with b values of 3.17 for males and 3.10 for females, indicating that body weight gain was faster than carapace width. The maturity stages of the P.pelagicus gonads were mostly at stages I and II, with a few reaching stages III and IV. The average gonad maturity stages increased from 2.42% in November to a peak of 5,83 % in February, then decreased in the following months. The primary spawning time occurs from December to February, characterized by changes in gonad color and a decrease in the body weight of the P. pelagicus after spawning. Hopefully, this study’s results can positively contribute to the sustainable management of crabs (P. pelagicus).

Hydration Awareness and Effect of Sports Nutrition Education Among Youth Baseball Players: A Pilot Study

OBJECTIVES The aim of this study was to investigate hydration awareness among youth baseball players and the effect of sports nutrition education on hydration-related indicators.METHODS Eighty-two youth baseball players who participated in a winter training camp hosted by the Korea Baseball Organization (KBO) participated in this study. A questionnaire was used to assess hydration awareness, and sports nutrition education focused on hydration-related topics was implemented. Hydration-related indicators such as fluid intake and urine color were measured to determine the effect of sports nutrition education.RESULTS Although the hydration awareness of youth baseball players was low, sports nutrition education had a positive effect on changes in fluid intake and urine color during the training camp.CONCLUSIONS Sports nutrition education should be actively implemented in the field to improve hydration awareness and status among youth baseball players.

Role of chemistry in modern world: Boons and banes of chemical coating effects on human health

Water is the principal component of fresh fruits and Vegetable which constitutes between 80 to 90% of a produce's fresh weight. Fruits are covered by a layer of natural wax which acts as a barrier to reduce moisture loss and at the same times give the fruit a shiny surface. Besides orange shellac, other common materials used for these purposes include starch, carrageenan, alginates, wood rosin and various waxes. Panko breadcrumbs are crucial to the vegetables being very crispy. The coatings are typically made from natural materials, such as CHI, cellulose, and pectin that are safe for human consumption. The multilayer coating method has been shown to be effective in extending the shelf life of a variety of fresh fruits and vegetables, including apples, strawberries, tomatoes, and cucumbers. Both natural waxes (carnauba, shellac, beeswax or resin) and petroleum-based waxes (usually proprietary formulae) are used, and often more than one wax is combined to create the desired properties for the fruit or vegetable being treated. However, chemical treatments, such as copper sulfate, rhodamine oxide, malachite green, and deadly carbide, used on green vegetables to enhance coloration and freshness, are often counterproductive to their nutritional value. There is multiple health risks associated with these chemicals. This study reveals that food preservatives have made a big difference in eating food every day. They help keep the food safe because they add these chemicals to prevent spoilage and retard prevent or control undesirable changes in flavor, color, texture, or consistency of food and nutritive value of food which means the Control natural spoilage of food.

Nondestructive freshness prediction of large yellow croaker (Pseudosciaena crocea) using computer vision and machine learning techniques based on pupil color.

Conventional methods for evaluating of fish freshness based on physiological and biochemical methods are often destructive, complicated, and costly. This study aimed to predict the freshness of large yellow croaker which was sampled every second day in 9 consecutive days at 4°C, using computer vision technology combined with pupil color parameters and different machine learning algorithms (back propagation neural network, BPNN; radial basis function neural network; support vector regression; and random forest regression, RFR). In the process of model building, the RFR model provided the most accurate prediction for the value of total volatile basic nitrogen (TVB-N), with the R-square of the test set ( ) of 0.993. The BPNN model exhibited the best fit for predicting the value of thiobarbituric acid (TBA), with of 0.959. Additionally, the RFR model was the most effective in forecasting total viable count (TVC), with of 0.935. After validation, the root mean square error values of the RFR model for predicting TVB-N value, TBA value, and TVC value were the lowest, which were 0.764, 0.067, and 0.219, respectively. It demonstrated the applicability and good predictive performance of the RFR model for predicting biochemical and microbiological indicators. These findings also demonstrated that monitoring the changes in pupil color could successfully predict the freshness of chilled fish. PRACTICAL APPLICATION: Application Scenario: Quality inspectors detect changes in thefreshness of large yellow croaker in real time from the beginning of distribution to the selling site.

Role of Chitosan in the Coloring of Berries and Phytochemical Changes in Physalis angulata L. During Harvest Maturity

Physalis angulata L. berries are green in the initial stage of maturity and turn yellow when fully mature due to an increase in carotenoids. However, the coloration of the epidermis of the berry should not be the reference for harvesting maturity, since the calyx is fully closed. The use of an edible chitosan coating delays the color changes in the berry by reducing the respiration rate. This work studies the effect of harvest maturity and chitosan on the shelf life and berry coloring in Physalis angulata L. Three factors were considered, being harvest maturity stage (green mature (GM), yellowish-green (YG) and yellow (Y)), chitosan coating (0, 0.5, and 1%), and storage time (10, 20, 30 days). The fruits were stored at 20 °C and 85% Rh. The results showed that on the harvesting stage, chitosan coating had a significant effect on the quality and shelf life of berries during storage time. The value of carotenoid and phenol contents, flavor index, chroma, and hue significantly increased with berry maturity. Chitosan delayed the decrease in chlorophyll, phenol contents, antioxidant capacity, berry maturity, and color change. The results show that in the berries coated with 1% chitosan during storage, changes in color were less in comparison with the control condition (no chitosan). The highest decrease of hue angle and color index (17.92°) was observed in the control. The highest total antioxidant (78.42%) was observed after 30 days of storage in MG berries treated with a 0.5% chitosan coating.

The Weathering of the Beech and Spruce Wood Impregnated with Pigmented Linseed Oil

This research aimed to examine the effects of a deep impregnation technique (Royal process) and surface coating using a linseed oil-based product, enhanced with small amounts of brown and grey pigments, on the natural and artificial weathering of wood. The treated and reference samples underwent natural weathering for five years and artificial weathering for 1900 h. Changes in color and surface roughness were assessed during weathering. For the artificially weathered samples, liquid water absorption was measured both before and after exposure. The impregnated and coated samples gradually lost their brown color, turning grey over time. More pronounced differences were observed during natural weathering, with the coated samples showing greater structural changes on the wood surface. In contrast, impregnated samples slowed down structural alterations compared to the reference samples. Both treatments effectively reduced water absorption before weathering, although this effect diminished after exposure. The treatments did not significantly impact the fire resistance of spruce and beechwood.

Combined Transcriptome and Metabolome Analyses Provide New Insights into the Changes in the Flesh Color of Anthocyanins in Strawberry (Fragaria × ananassa (Weston) Duchesne ex Rozier)

Background: Strawberries are bright in color, sweet and sour in taste, and rich in nutrients and flavonoid compounds such as anthocyanins and proanthocyanidins. The synthesis and accumulation of anthocyanins are the decisive factors that make strawberries appear bright red. From the perspective of plant breeding, a change in flesh color is an important goal. Methods: In this study, two strawberry plants with different flesh colors were selected, and transcriptome and metabolome analyses were performed during the color change period (S1) and ripening period (S2). Results: RNA-seq revealed a total of 13,341 differentially expressed genes (DEGs) between and within materials, which were clustered into 5 clusters. A total of 695 metabolites were detected via metabolome analysis, and 243 differentially regulated metabolites (DRMs) were identified. The anthocyanin biosynthesis, starch and sucrose metabolism and glycolysis/gluconeogenesis pathways were determined to be important regulatory pathways for changes in strawberry flesh color through a joint analysis of RNA-seq data and the metabolome. The leucoanthocyanidin reductase (LAR) and chalcone synthase (CHS) gene is a key gene related to anthocyanins, cinnamic acid, and phenylalanine. In addition, through joint RNA-seq and metabolome analyses combined with weighted gene co-expression network analysis (WGCNA), we identified 9 candidate genes related to strawberry flesh color. Conclusions: Our research findings have laid the groundwork for a more comprehensive understanding of the molecular mechanisms governing the color transformation in strawberry flesh. Additionally, we have identified novel genetic resources that can be instrumental in advancing research related to strawberry color change.

Strategic Design of Anion-Responsive Triarylboranes Exhibiting Colorimetric and Fluorometric Red-Shift for Sensing and Optoelectronic Applications.

Triarylboranes (TABs) have been employed as colorimetric and/or fluorometric anion sensors. The majority of TAB-based anion sensors exhibit blue-shift modes of absorption and photoluminescence (PL) or turn off of PL, attributed to the intrinsic electronic polarity of the trivalent boron unit in their molecular designs. In this Concept article, we introduce a novel approach to modulating the photophysical properties of TABs toward a red-shift mode by balancing the dual, opposing roles of the amine-bridged TAB (phenazaborine). This molecular design strategy enables significant changes in color and emission response to anions, shifting to the lower energy regime in solution. Additionally, this approach is applicable to the solid-state modulation of PL in films and organic light-emitting diodes (OLEDs).

Effects of curing method on quality of vanilla pod using a greenhouse effect dryer

The problem faced in Indonesian vanilla production and export is the high variation of vanilla quality. This is caused by some factors, including variations in the age of harvest, curing process and drying method. This study aimed to determine the effects of curing using a greenhouse effect (GHE) dryer on the quality of vanilla pods. The vanilla pod was harvested and subjected to the withering process by soaking in water at a temperature of 60-65°C for 2 mins. After that, the sweating process was carried out for 2 days at room temperature. Then, the samples were subjected to four curing treatments [drying with GHE dryer with no sweating process (P1), drying with GHE dryer combined with sweating in the first two days (P2), drying with GHE dryer combined with sweating in the first four days (P3) and drying with sun drying combined with sweating in the first two days (P4)]. Drying was continued for all treatments until the water content of the vanilla pod reached 34-35%. The changes in color, shape, weight loss, water and vanilla content of vanilla pod before and after the curing process were observed. The results showed that drying with a GHE dryer combined with sweating in the first four days (P3) significantly affects the vanillin content and aroma of cured vanilla pod. There was no effect of curing on the color of cured vanilla pods. The P3 treatment was the best curing method since the vanillin content was highest with acceptable color and aroma.

Antibacterial activity of green synthesized copper oxide nanoparticles against multidrug-resistant bacteria

Using plant extracts in the green synthesis of nanoparticles has become an environmentally acceptable approach. In our study, copper oxide nanoparticles (CuO NPs) were synthesized using ethanolic extracts of Azadirachta indica and Simmondsia chinensis. CuO NP formation was confirmed by the change in color and by UV‒visible spectroscopy (CuO NPs peaked at a wavelength of 344 nm). TEM images confirmed the semispherical shape of the CuO NPs, with particle sizes ranging from 30.9 to 10.7 nm. The antibacterial activity of these NPs was evaluated by using the agar diffusion method against clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa, Acinetobacter spp., Klebsiella pneumoniae, and Stenotrophomonas maltophilia. The minimum inhibitory concentration (MIC) of CuO NPs ranged from 62.5 to 125 µg/ml. In contrast, the antioxidant activity and antibiofilm activity of CuO NPs ranged from 31.1 to 92.2% at 125–500 µg/ml and 62.2–95%, respectively, at 125 –62.5 µg/ml. Our results confirmed that CuO NPs had IC50s of 383.41 ± 3.4 and 402.73 ± 1.86 at 250 µg/mL against the HBF4 cell line. Molecular docking studies with CuO NPs suggested that penicillin-binding protein 4 (PBP4) and beta-lactamase proteins (OXA-48) strongly bind to S. aureus and K. pneumoniae, respectively, with CuO NPs. Our study confirms the promising use of CuO NPs in treating pathogenic bacteria and that CuO NPs could be possible alternative antibiotics. This study supports the pharmaceutical and healthcare sectors in Egypt and worldwide.

Structural Design of Hybrid Manganese(II) Halides for High Quantum Efficiency and Specific Response to Methanol.

Manganese(II) halides have been a new generation of optoelectronic materials due to their fascinating luminescent properties, however, lacking specific solvent-responsive analogues with high quantum efficiency. Herein, we prepared three single crystals, [Pr(MIm)2][MnBr4] ([Pr(MIm)2]2+ = 1,3-di(methylimidazolium)-propane, Compound 1), [Pr(EIm)2][MnBr4] ([Pr(EIm)2]2+ = 1,3-di(ethylimidazolium)-propane, Compound 2), and [Bu(MIm)2][MnBr4] ([Bu(MIm)2]2+ = 1,4-di(methylimidazolium)-butane, Compound 3), where different Bola-type cations were chosen as organic components to separate [MnBr4]2- tetrahedrons. All three compounds emitted bright green light with excellent quantum yields of 95.3, 80.0, and 96.2%, benefiting from the large Mn···Mn distance. More interestingly, Compound 3 showed a highly selective response to methanol in a series of tested organic solvents, with a rapid and reversible change in emission color from green to red. The single crystal of [Bu(MIm)2][MnBr4]·CH3OH with red emission proved that the luminescence switching was attributed to the adsorption of CH3OH molecules into the lattice space in the form of the O-H···Br hydrogen bonds. To our knowledge, for tetrahedrally coordinated Mn(II) species, the reversible emission color switching between green and red triggered by a solvent without the change of coordination number is achieved for the first time, providing promising applications for the specific detection of methanol.