Age-Related Changes in Survival Behaviour in Parasite-Free Hatchery-Reared Rainbow Trout (Oncorhynchus mykiss).

Millions of hatchery-reared Rainbow trout are currently released in Australian waters to support recreational fisheries objectives, yet many of these fish die soon after release. In addition, little is known whether these fish harbour parasites that can potentially threaten freshwater ecosystems and human health. Here, we tested the behaviour of hatchery-reared trout using six tank-based tests at six different ages to evaluate their chances of survival and then dissected fish to investigate parasite prevalence. At 7 weeks of age fish readily emerged from a hide and showed the greatest number of startle responses to predators. Behaviour around 25-29 weeks of age was relatively "shy", staying in shelter and avoiding open water. At around 37-41 weeks of age though, behaviour changed, with fish emerging from a hide more readily and exploring the environment. Interestingly, at 58 weeks of age fish were slower to initiate exploration, possibly indicating a return to "shyer" behaviour. All fish underwent thorough parasite examination, revealing no infections. We conclude that knowledge of the behaviour of hatchery-reared fish at different ages is useful for decisions around the timing of release that balance the needs of recreational fishers whilst managing the impact on freshwater ecosystem.

Luminescent Supramolecular Metallogels: Drug Loading and Eu(III) as Structural Probe.

Supramolecular metallogels combine the rheological properties of gels with the color, magnetism, and other properties of metal ions. Lanthanide ions such as Eu(III) can be valuable components of metallogels due to their fascinating luminescence. In this work, we combine Eu(III) and iminodiacetic acid (IDA) into luminescent hydrogels. We investigate the tailoring of the rheological properties of these gels by changes in their metal:ligand ratio. Further, we use the highly sensitive Eu(III) luminescence to obtain information about the chemical structure of the materials. In special, we take advantage of computational calculations to employ an indirect method for structural elucidation, in which the simulated luminescent properties of candidate structures are matched to the experimental data. With this strategy, we can propose molecular structures for different EuIDA gels. We also explore the usage of these gels for the loading of bioactive molecules such as OXA, observing that its aldose reductase activity remains present in the gel. We envision that the findings from this work could inspire the development of luminescent hydrogels with tunable rheology for applications such as 3D printing and imaging-guided drug delivery platforms. Finally, Eu(III) emission-based structural elucidation could be a powerful tool in the characterization of advanced materials.

Interfacial structurization between triolein and water from pH and buffer ions.

HYPOTHESIS: Understanding and manipulating the oil/water interface is important across various industries, including food, pharmaceuticals, cosmetics, and detergents. Many of these processes occur under elevated pH conditions in buffer systems, where base-catalyzed hydrolysis of triglyceride ester bonds leads to amphiphilic reaction products such as fatty acids. EXPERIMENTS: Here, pH-triggered alterations of the triolein/water interface are analyzed in the presence of phosphate (PB) and tris(hydroxymethyl)aminomethane (TRIS). Ellipsometry at the liquid/liquid interface, tensiometry, and scanning small angle X-ray scattering are used to study the formation of structures at the oil/water interface. Confocal Raman microscopy, nuclear magnetic resonance spectroscopy, and in silico modeling analyze compositional changes in the interfacial region. FINDINGS: pH and buffer ions were discovered to significantly modify the triglyceride/water interface, contrary to the decane/water control. Decreasing interfacial tensions from 32.4 to 2.2 mN/m upon pH increase from 6.5 to 9.5 is seen with multilamellar interfacial layers forming at pH around 9.0 in the presence of TRIS. Oleic acid from triolein hydrolysis and its further interaction with TRIS is held responsible for this. The new understanding can guide the design of pH- and ion-responsive functional materials and optimize industrial processes involving triglyceride/water interfaces.

Antipsychotic agents in anxiety disorders: An umbrella review.

BACKGROUND: Although not approved for the treatment of anxiety disorders (except trifluoperazine) there is ongoing off-label, unapproved use of first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs) for anxiety disorders. There have been systematic reviews and meta-analyses on the use of antipsychotics in anxiety disorders, most of which focused on SGAs. OBJECTIVE: The specific aims of this umbrella review are to: (1) Evaluate the evidence of efficacy of FGAs and SGAs in anxiety disorders as an adjunctive treatment to traditional antidepressant treatments and other nonantipsychotic medications; (2) Compare monotherapy with antipsychotics to first-line treatments for anxiety disorders in terms of effectiveness, risks, and side effects. The review protocol is registered on PROSPERO (CRD42021237436). METHODS: An initial search was undertaken to identify systematic reviews and meta-analyses from inception until 2020, with an updated search completed August 2021 and January 2023. The searches were conducted in PubMed, MEDLINE (Ovid), EMBASE (Ovid), APA PsycInfo (Ovid), CINAHL Complete (EBSCOhost), and the Cochrane Library through hand searches of references of included articles. Review quality was measured using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews) scale. RESULTS: The original and updated searches yielded 1796 and 3744 articles respectively, of which 45 were eligible. After final review, 25 systematic reviews and meta-analyses were included in the analysis. Most of the systematic reviews and meta-analyses were deemed low-quality through AMSTAR-2 with only one review being deemed high-quality. In evaluating the monotherapies with antipsychotics compared with first-line treatments for anxiety disorder there was insufficient evidence due to flawed study designs (such as problems with randomization) and small sample sizes within studies. There was limited evidence suggesting efficacy of antipsychotic agents in anxiety disorders other than quetiapine in generalized anxiety disorder (GAD). CONCLUSIONS: This umbrella review indicates a lack of high-quality studies of antipsychotics in anxiety disorders outside of the use of quetiapine in GAD. Although potentially effective for anxiety disorders, FGAs and SGAs may have risks and side effects that outweigh their efficacy, although there were limited data. Further long-term and larger-scale studies of antipsychotics in anxiety disorders are needed.

Substrate suppression of oxidation process in pnictogen monolayers.

2D materials present an interesting platform for device designs. However, oxidation can drastically change the system's properties, which need to be accounted for. Through ab initio calculations, we investigated freestanding and SiC-supported As, Sb, and Bi mono-elemental layers. The oxidation process occurs through an O2 spin-state transition, accounted for within the Landau-Zener transition. Additionally, we have investigated the oxidation barriers and the role of spin-orbit coupling. Our calculations pointed out that the presence of SiC substrate reduces the oxidation time scale compared to a freestanding monolayer. We have extracted the energy barrier transition, compatible with our spin-transition analysis. Besides, spin-orbit coupling is relevant to the oxidation mechanisms and alters time scales. The energy barriers decrease as the pnictogen changes from As to Sb to Bi for the freestanding systems, while for SiC-supported, they increase across the pnictogen family. Our computed energy barriers confirm the enhanced robustness against oxidation for the SiC-supported systems.

Breastfeeding and autism spectrum disorder: case-control study / Transtorno do espectro do autismo e aleitamento materno: estudo de caso controle

Abstract Objectives: to evaluate the association between breastfeeding and Autism Spectrum Disorder (ASD) in children and adolescents. Methods: this is a case-control study carried out in the north of the state of Minas Gerais, Brazil, which included 248 children and adolescents diagnosed with ASD (case group) and 886 children and adolescents without a diagnosis of ASD (control group).Interviews were conducted with the mothers of children and adolescents and a semi-structured questionnaire was used to collect data. For data analysis, a multiple logistic regression model was adopted. The magnitude of associations was estimated by the odds ratio (OR). Three multiple models were fitted: Model 1: presence or absence of breastfeeding; Model 2: duration of breastfeeding; Model 3: duration of exclusive breastfeeding. Results: ASD was associated with the absence of breastfeeding in the three adjusted models: Model 1: OR=2.1, CI95%=1.1-4.1; Model 2: OR=2.3, CI95%=1.2-4.5; Model 3: OR=2.3, CI95%=1.2-4.5. Conclusions: individuals with ASD were more likely to have not received breastfeeding, however, due to the nature of case control studies, it cannot be stated that breastfeeding prevents ASD. Conducting a cohort study may clarify this relationship.

Resumo Objetivos: avaliar a associação entre aleitamento materno e Transtorno do Espectro do Autismo (TEA) em crianças e adolescentes. Métodos: trata-se de um estudo caso-controle realizado no norte de Minas Gerais, Brasil, que incluiu 248 crianças e adolescentes com diagnóstico de TEA (grupo caso) e 886 crianças e adolescentes sem diagnóstico de TEA (grupo controle). Foram realizadas entrevistas com as mães das crianças e adolescentes e utilizado um questionário semiestruturado para coleta dos dados. Para análise dos dados foi adotado modelo de regressão logística múltipla. A magnitude das associações foi estimada pela Odds Ratio (OR). Três modelos múltiplos foram ajustados: Modelo 1: presença ou ausência de aleitamento materno; Modelo 2: duração do aleitamento materno; Modelo 3: duração do aleitamento materno exclusivo. Resultados: o TEA foi associado à ausência de aleitamento materno nos três modelos ajustados: Modelo 1: OR=2,1, IC95%=1,1-4,1; Modelo 2: OR=2,3, IC95%=1,2-4,5; Modelo 3: OR=2,3, IC95%=1,2-4,5. Conclusões: os indivíduos com TEA tiveram maiores chances de não terem recebido aleitamento materno, no entanto, devido à natureza dos estudos de caso-controle, não se pode afirmar que o aleitamento materno previna o TEA. A realização de um estudo de coorte poderá esclarecer essa relação.

Human antimicrobial peptide inactivation mechanism of enveloped viruses.

HYPOTHESIS: Enveloped viruses are pivotal in causing various illnesses, including influenza and COVID-19. The antimicrobial peptide LL-37, a critical part of the human innate immune system, exhibits potential as an antiviral agent capable of thwarting these viral threats. Its mode of action involves versatile and non-specific interactions that culminate in dismantling the viral envelope, ultimately rendering the viruses inert. However, the exact mechanism of action is not yet understood. EXPERIMENTS: Here, the mechanism of LL-37 triggered changes in the structure and function of an enveloped virus is investigated. The bacteriophage "Phi6" is used as a surrogate for pathogenic enveloped viruses. Small angle X-ray and neutron scattering combined with light scattering techniques demonstrate that LL-37 actively integrates into the virus's lipid envelope. FINDINGS: LL-37 addition to Phi6 leads to curvature modification in the lipid bilayer, ultimately separating the envelope from the nucleocapsid. Additional biological assays confirm the loss of virus infectivity in the presence of LL-37, which coincides with the structural transformations. The results provide a fundamental understanding of the structure-activity relationship related to enveloped viruses. The knowledge of peptide-virus interactions can guide the design of future peptide-based antiviral drugs and therapies.

Dexmedetomidine in the Treatment of Depression: An Up-to-date Narrative Review.

Depressive disorders (DD) are common, and their prevalence is expected to rise over the next decade. Depressive disorders are linked to significant morbidity and mortality. The clinical conundrum of depressive disorders lies in the heterogeneity of their phenomenology and etiology. Further, the currently available antidepressants have several limitations, including a delayed onset of action, limited efficacy, and an unfavorable side effect profile. In this review, Dexmedetomidine (DEX), a highly selective and potent α2-adrenergic receptor (α2-AR) agonist, is proposed as a potentially novel antidepressant with multiple mechanisms of action targeting various depression pathophysiological processes. These mechanisms include modulation of the noradrenergic system, regulation of neuroinflammation and oxidative stress, influence on the Brain-Derived Neurotrophic Factor (BDNF) levels, and modulation of neurotransmitter systems, such as glutamate. The review begins with an introduction before moving on to a discussion of DEX's pharmacological features. The pathophysiological and phenomenological targets of DD are also explored, along with the review of the existing preclinical and clinical evidence for DEX's putative anti-depressant effects. Finally, the review ends by presenting the pertinent conclusions and future directions.

Bold-shy personality traits of globally invasive, native and hatchery-reared fish.

Bold behaviour of non-native species is hypothesized to facilitate invasion success, yet extreme boldness in wild and domesticated animals can be maladaptive. The purpose of this study was to compare individual behaviour among Australian native hatchery-reared (n = 33) and wild (n = 38) Murray cod (Maccullochella peelii) with invasive common carp (Cyprinus carpio; n = 30). Three laboratory tests measured individual behaviour: (1) emergence from a shelter, (2) exploration of a novel environment, and (3) approaching a predator. Wild invasive carp and hatchery-reared cod were generally faster and more likely to emerge and explore novel environments when compared with wild Murray cod. The 'bold-type' behaviours of hatchery-reared native cod were more like invasive carp than they were to 'shy-type' wild conspecifics, yet an important difference was that hatchery-reared cod spent substantially more time near a large predator while carp rapidly escaped. We suggest that these results are consistent with a bold-type invasion syndrome in invasive carp and learned boldness of hatchery-reared Murray cod. The propensity of invasive carp to rapidly explore and enter new environments, along with a fast predator escape response may have been important to their invasion success, while extreme risk-taking and predator naivety of hatchery-reared Murray cod may exacerbate post-release mortality rates in fisheries and conservation stocking programmes.

De novo design of bioactive phenol and chromone derivatives for inhibitors of Spike glycoprotein of SARS-CoV-2 in silico.

This work presents the synthesis of 12 phenol and chromone derivatives, prepared by the analogs, and the possibility of conducting an in silico study of its derivatives as a therapeutic alternative to combat the SARS-CoV-2, pathogen responsible for COVID-19 pandemic, using its S-glycoprotein as a macromolecular target. After the initial screening for the ranking of the products, it was chosen which structure presented the best energy bond with the target. As a result, derivative 4 was submitted to a molecular growth study using artificial intelligence, where 8436 initial structures were obtained that passed through the interaction filters and similarity to the active glycoprotein pocket through the MolAICal computational package. Thus, 557 Hits with active configuration were generated, which is very promising compared to the BLA reference link for inhibiting the biological target. Molecular dynamics also simulated these compounds to verify their stability within the active protein site to seek new therapeutic propositions to fight against the pandemic. The Hit 48 and 250 are the most active compounds against SARS-CoV-2. In summary, the results show that the Hit 250 would be more active than the natural compound, which could be further developed for further testing against SARS-CoV-2. The study employs the de novo approach to design new drugs, combining artificial intelligence and molecular dynamics simulations to create efficient molecular structures. This research aims to contribute to the development of effective therapeutic strategies against the pandemic.

Single particle investigation of triolein digestion using optical manipulation, polarized video microscopy, and SAXS.

HYPOTHESIS: Understanding how soft colloids, such as food emulsion droplets, transform based on their environment is critical for various applications, including drug and nutrient delivery and biotechnology. However, the mechanisms behind colloidal transformations within individual oil droplets still need to be better understood. EXPERIMENTS: This study employs optical micromanipulation with microfluidics and polarized optical video microscopy to investigate the pancreatic lipase- and pH-triggered colloidal transformations in a single triolein droplet. Small-angle X-ray scattering (SAXS) provides complementary statistical insights and allows for detailed structural assignment. FINDINGS: Optical video microscopy recorded the transformation of individual triolein emulsion droplets, with the smooth surface of these spherical particles becoming rough and the entire volume eventually being affected. The polarized microscopy revealed the coexistence of at least two distinct structures in a single particle during digestion, with their ratio and distribution altered by pH. The SAXS analysis assigned the optical anisotropy to emulsified inverse hexagonal- and multilamellar phases, coexisting with isotropic structures such as the micellar cubic phase. These results can help understand the phase transformations inside an emulsion droplet during triglyceride digestion and guide the design of advanced food emulsions.

Supramolecular design of CO2-responsive lipid nanomaterials.

HYPOTHESIS: Stimuli-responsive materials can innovate in various fields, including food and pharmaceutical sciences. Their response to a specific stimulus can be utilized to release loaded bioactive molecules or sense their presence. The biocompatibility and abundance of CO2 in the environment make it an exciting stimulus for such applications. We hypothesize the formation of CO2-responsive self-assemblies of oleyl-amidine in water. Their integration into glycerol-monooleate-based (GMO) dispersions is further thought to form CO2-switchable liquid crystalline nanoparticles. The switch from an non-charged acetamidine surfactant to its cationic amidinium form triggers curvature changes that ultimately induces phase transitions. EXPERIMENTS: The CO2-switchable lipid (E)-N,N-dimethyl-N-((Z)-octadec-9-en1-yl)acetimidamide (OAm) is synthesized and formulated into emulsions and dispersed liquid crystals with GMO. The supramolecular structure and its response to CO2 are characterized using small angle X-ray scattering, dynamic light scattering, ζ-potential measurements and cryogenic transmission electron microscopy. FINDINGS: Depending on the composition, OAm is discovered to self-assemble into a variety of CO2-responsive lyotropic liquid crystalline structures that can be dispersed in excess water. CO2-triggered colloidal transformations from unstructured OAm-in-water emulsions to direct micelles; dispersed inverse hexagonal phase to direct rod-like micelles, and sponge phase to vesicles are discovered. These structural changes are driven by the reaction of OAm's amidine headgroup with CO2. The results provide a fundamental understanding of CO2-triggered functional nanomaterials and may guide their future design into delivery platforms and biosensors.

Prevalence of internet addiction and associated factors in students / Prevalência de adicção em internet e fatores associados em estudantes

Objective: A cross-sectional study that estimated the prevalence of Internet Addiction and associated factors among High School and College students in Montes Claros - Minas Gerais, Brazil. Methods: Internet Addiction was evaluated through the Internet Addiction Test, and demographic, socioeconomic, and lifestyle factors, as well as internet usage profile characteristics, were examined. Descriptive analysis and the Poisson regression model were applied. Results: Of the 2,519 participants, 52.3% were considered with Internet Addiction Problems. In High School, the following factors were identified: are women and girls, age over >16, class C, alcohol consumption, impaired sleep, frequent use of social networks, and time spent connected. In Higher Education, the following factors: are women and girls, age over >23, paid activity, class C and D/E, alcohol consumption, impaired sleep, imbalanced diet, frequent use of social networks, and time spent connected. Conclusion: There was an expressive prevalence of Internet Addiction Problems, an outcome associated with the demographic, socioeconomic, lifestyle, and internet use characteristics.

Objetivo: Estudo transversal que estimou prevalência de Adicção em Internet e fatores associados entre estudantes do Ensino Médio e Superior em Montes Claros - Minas Gerais, Brasil. Métodos: A Adicção em Internet foi avaliada pelo Internet Addiction Test e se investigaram fatores demográficos, socioeconômicos, estilo de vida e perfil de uso de internet. Foram realizadas análises descritivas e modelo de regressão de Poisson. Resultados: Dos 2.519 participantes, 52,3% apresentaram problemas de Adicção em Internet. No grupo de estudantes de Ensino Médio examinado, identificaram-se os seguintes fatores: sexo feminino, idade >16, classe C, consumo de álcool, sono prejudicado, uso frequente das redes sociais e tempo de conexão. No Ensino Superior, foram constatados: sexo feminino, idade >23, atividade remunerada, classe C e D/E, consumo de álcool, sono prejudicado, alimentação não balanceada, uso frequente das redes sociais e tempo de conexão. Conclusão: Houve expressiva prevalência de Problemas com Adicção em Internet, desfecho associado a características demográficas, socioeconômicas, ao estilo de vida e ao uso da internet.

The association among the consumption of ultra-processed food and body image, nutritional status and physical activity of pregnant women at the primary health care / Associação entre o consumo de alimentos ultraprocessados e imagem corporal, estado nutricional e atividade física de gestantes na Atenção Primária à Saúde

Abstract Objectives: to analyze the consumption of ultra-processed food and its association with body image, physical activity, nutritional status and self-assessment on food of pregnant women enrolled in the Primary Health Care. Methods: this is a cross-sectional study carried out with pregnant women enrolled in the Family Health Strategy in the city of Montes Claros, Minas Gerais. Data were collected through a questionnaire. The dependent variable was the consumption of ultra-processed food, and the independent ones addressed body appearance, physical activity, nutritional status, self-assessment on food and food consumption. Descriptive analysis was carried out and for association of analysis, the linear regression model was used with crude and adjusted associations. Results: 1,185 pregnant women participated in the study. Caloric intake from ultra-processed food represented 32.0% of these women's daily diet. There was an association between consumption of ultra-processed food and physical activity (β=-0.08; p<0.01), pre-gestional nutritional status (β=-0,12; p<0.01) and body image (β =0.08; p=0.01). Conclusion: the pregnant women presented high consumption of ultra-processed food. Having a negative body image, the lowest level of physical activity, and high pre-gestational nutritional status are conditions that influenced the consumption of these food.

Resumo Objetivos: analisar o consumo de alimentos ultraprocessados e sua associação com imagem corporal, atividade física, estado nutricional e autoavaliação alimentar de gestantes cadastradas na Atenção Primária à Saúde. Métodos: trata-se de um estudo transversal, realizado com gestantes cadastradas na Estratégia Saúde da Família do município de Montes Claros, Minas Gerais. Os dados foram coletados por meio de um questionário. A variável dependente foi consumo de alimentos ultraprocessados, e as independentes abordaram aspecto corporal, atividade física, estado nutricional, autoavaliação alimentar e consumo alimentar. Realizou-se análise descritiva e para análise de associação, utilizou-se o modelo de regressão linear com associações brutas e ajustadas. Resultados: participaram do estudo 1.185 gestantes. O consumo calórico proveniente dos ultraprocessados representou 32,0% da dieta diária dessas mulheres. Verificou-se associação entre consumo de ultraprocessados com atividade física (β=-0,08; p<0,01), estado nutricional pré-gestacional (β=-0,12; p<0,01) e imagem corporal (β=0,08; p=0,01). Conclusão: as gestantes apresentaram alto consumo de alimentos ultraprocessados. Ter imagem corporal negativa, menor nível de atividade física, estado nutricional pré-gestacional elevado são condições que influenciaram o consumo desses alimentos.

Habit Formation and the Effect of Repeated Stress Exposures on Cognitive Flexibility Learning in Horses.

Horse training exposes horses to an array of cognitive and ethological challenges. Horses are routinely required to perform behaviours that are not aligned to aspects of their ethology, which may delay learning. While horses readily form habits during training, not all of these responses are considered desirable, resulting in the horse being subject to retraining. This is a form of cognitive flexibility and is critical to the extinction of habits and the learning of new responses. It is underpinned by complex neural processes which can be impaired by chronic or repeated stress. Domestic horses may be repeatedly exposed to multiples stressors. The potential contribution of stress impairments of cognitive flexibility to apparent training failures is not well understood, however research from neuroscience can be used to understand horses' responses to training. We trained horses to acquire habit-like responses in one of two industry-style aversive instrumental learning scenarios (moving away from the stimulus-instinctual or moving towards the stimulus-non-instinctual) and evaluated the effect of repeated stress exposures on their cognitive flexibility in a reversal task. We measured heart rate as a proxy for noradrenaline release, salivary cortisol and serum Brain Derived Neurotrophic Factor (BDNF) to infer possible neural correlates of the learning outcomes. The instinctual task which aligned with innate equine escape responses to aversive stimuli was acquired significantly faster than the non-instinctual task during both learning phases, however contrary to expectations, the repeated stress exposure did not impair the reversal learning. We report a preliminary finding that serum BDNF and salivary cortisol concentrations in horses are positively correlated. The ethological salience of training tasks and cognitive flexibility learning can significantly affect learning in horses and trainers should adapt their practices where such tasks challenge innate equine behaviour.

Understanding and addressing COVID-19 vaccine hesitancy in low and middle income countries and in people with severe mental illness: Overview and recommendations for Latin America and the Caribbean.

Despite the speedy development of vaccines for COVID-19, their rollout has posed a major public health challenge, as vaccine hesitancy (VH) and refusal are high. Addressing vaccine hesitancy is a multifactorial and context-dependent challenge. This perspective focuses on VH in the world region of Latin America and the Caribbean (LAC) and includes people suffering from severe mental illness, therefore covering populations and subpopulations often neglected in scientific literature. We present an overview of VH in LAC countries, discussing its global and historical context. Vaccine uptake has shown to widely vary across different subregions of LAC. Current data points to a possible correlation between societal polarization and vaccination, especially in countries going through political crises such as Brazil, Colombia, and Venezuela. Poor accessibility remains an additional important factor decreasing vaccination rollout in LAC countries and even further, in the whole Global South. Regarding patients with severe mental illness in LAC, and worldwide, it is paramount to include them in priority groups for immunization and monitor their vaccination coverage through public health indicators.

Doped Carbon Quantum Dots/PVA Nanocomposite as a Platform to Sense Nitrite Ions in Meat.

A sensor device based on doped-carbon quantum dots is proposed herein for detection of nitrite in meat products by fluorescence quenching. For the sensing platform, carbon quantum dots doped with boron and functionalized with nitrogen (B,N-Cdot) were synthesized with an excellent 44.3% quantum yield via a one-step hydrothermal route using citric acid, boric acid, and branched polyethylenimine as carbon, boron, and nitrogen sources, respectively. After investigation of their chemical structure and fluorescent properties, the B,N-Cdot at aqueous suspensions showed high selectivity for NO2- in a linear range from 20 to 50 mmol L-1 under optimum conditions at pH 7.4 and a 340 nm excitation. Furthermore, the prepared B,N-Cdots successfully detected NO2- in a real meat sample with recovery of 91.4-104% within the analyzed range. In this manner, a B,N-Cdot/PVA nanocomposite film with blue emission under excitation at 360 nm was prepared, and a first assay detection of NO2- in meat products was tested using a smartphone application. The potential application of the newly developed sensing device containing a highly fluorescent probe should aid in the development of a rapid and inexpensive strategy for NO2- detection.