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The increased environmental presence of micro-/nanoplastics (MNPLs) and the potential health risks associated with their exposure classify them as environmental pollutants with special environmental and health concerns. Consequently, there is an urgent need to investigate the potential risks associated with secondary MNPLs. In this context, using "true-to-life" MNPLs, resulting from the laboratory degradation of plastic goods, may be a sound approach. These non-commercial secondary MNPLs must be labeled to track their presence/journeys inside cells or organisms. Because the cell internalization of MNPLs is commonly analyzed using fluorescence techniques, the use of fluorescent dyes may be a sound method to label them. Five different compounds comprising two chemical dyes (Nile Red and Rhodamine-B), one optical brightener (Opticol), and two industrial dyes (Amarillo Luminoso and iDye PolyPink) were tested to determine their potential for such applications. Using commercial standards of polystyrene nanoplastics (PSNPLs) with an average size of 170 nm, different characteristics of the selected dyes such as the absence of impact on cell viability, specificity for plastic staining, no leaching, and lack of interference with other fluorochromes were analyzed. Based on the overall data obtained in the wide battery of assays performed, iDye PolyPink exhibited the most advantages, with respect to the other compounds, and was selected to effectively label "true-to-life" MNPLs. These advantages were confirmed using a proposed protocol, and labeling titanium-doped PETNPLs (obtained from the degradation of milk PET plastic bottles), as an example of "true-to-life" secondary NPLs. These results confirmed the usefulness of iDye PolyPink for labeling MNPLs and detecting cell internalization.

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This work explores the transformative role of graphene in enhancing the performance of surface plasmon resonance (SPR)-based biosensors. The motivation for this review stems from the growing interest in the unique properties of graphene, such as high surface area, excellent electrical conductivity, and versatile functionalization capabilities, which offer significant potential to improve the sensitivity, specificity, and stability of SPR biosensors. This review systematically analyzes studies published between 2010 and 2023, covering key metrics of biosensor performance. The findings reveal that the integration of graphene consistently enhances sensitivity. Specificity, although less frequently reported numerically, showed promising results, with high specificity achieved at sub-nanomolar concentrations. Stability enhancements are also significant, attributed to the protective properties of graphene and improved biomolecule adsorption. Future research should focus on mechanistic insights, optimization of integration techniques, practical application testing, scalable fabrication methods, and comprehensive comparative studies. Our findings provide a foundation for future research, aiming to further optimize and harness the unique physical properties of graphene to meet the demands of sensitive, specific, stable, and rapid biosensing in various practical applications.

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This study determines the sensitivity and specificity of a screening test to detect perceptual abnormalities and whether there are differences between gender. Vision is a complex process involving visual perception. Any alterations can affect learning, so having a screening test in Spanish that is easy to use and reliable for timely diagnosis will reduce the percentage of visuo-perceptual interference during learning process. A total of 200 subjects participated, aged between 8 and 15 years old, with good visual acuity, and no strabismus, amblyopia, ocular pathology, or neurological damage. The Petrosyan questionnaire (screening test) was employed to identify symptoms associated with perceptual impairment, and a subsequent assessment was conducted to evaluate perceptual abilities. The mean age was 11.5 years (57% male; 44% female). The screening test indicated that 30% of the subjects were suspected of having perceptual alteration, while 24% were diagnosed with a real alteration in perceptual abilities. The sensitivity was 1 and the specificity was 0.92. The Spanish version of the Petrosyan questionnaire has high sensitivity and specificity values and is therefore considered very accurate for identifying the need for a perceptual assessment. There are statistically significant differences in perceptual abilities according to gender. The female group shows more symptomatology and a higher percentage of alteration in perceptual skills.

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COVID-19 laboratory diagnosis primarily relies on molecular tests, highly sensitive during early infection stages with high viral loads. As the disease progresses, sensitivity decreases, requiring antibody detection. Since the beginning of the pandemic, serological tests have been developed and made available in Brazil, but their diagnostic performance varies. This study evaluated the IBMP ELISA IgA/IgM/IgG COVID-19 kit performance in detecting SARS-CoV-2 antibodies. A total of 90 samples, including 64 from COVID-19 patients and 26 pre-pandemic donors, were assessed based on time post symptom onset (0-7, 8-14, and 15-21 days). The kit showed 61% sensitivity, 100% specificity, and 72% accuracy overall. Sensitivity varied with time, being 25%, 57%, and 96% for 0-7, 8-14, and 15-21 days, respectively. Similar variations were noted in other commercial tests. The Gold ELISA COVID-19 (IgG/IgM) had sensitivities of 31%, 71%, and 100%, while the Anti-SARS-CoV-2 NCP ELISA (IgG) and Anti-SARS-CoV-2 NCP ELISA (IgM) showed varying sensitivities. The IBMP ELISA kit displayed high diagnostic capability, especially as the disease progressed, complementing COVID-19 diagnosis. Reproducibility assessment revealed minimal systematic and analytical errors. In conclusion, the IBMP ELISA IgA/IgM/IgG COVID-19 kit is a robust tool for detecting anti-SARS-CoV-2 antibodies, increasing in efficacy over the disease course, and minimizing false negatives in RT-PCR COVID-19 diagnosis.

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The PKC-related kinases (PRKs, also termed PKNs) are important in cell migration, cancer, hepatitis C infection, and nutrient sensing. They belong to a group of protein kinases called AGC kinases that share common features like a C-terminal extension to the catalytic domain comprising a hydrophobic motif. PRKs are regulated by N-terminal domains, a pseudosubstrate sequence, Rho-binding domains, and a C2 domain involved in inhibition and dimerization, while Rho and lipids are activators. We investigated the allosteric regulation of PRK2 and its interaction with its upstream kinase PDK1 using a chemical biology approach. We confirmed the phosphoinositide-dependent protein kinase 1 (PDK1)-interacting fragment (PIF)-mediated docking interaction of PRK2 with PDK1 and showed that this interaction can be modulated allosterically. We showed that the polypeptide PIFtide and a small compound binding to the PIF-pocket of PRK2 were allosteric activators, by displacing the pseudosubstrate PKL region from the active site. In addition, a small compound binding to the PIF-pocket allosterically inhibited the catalytic activity of PRK2. Together, we confirmed the docking interaction and allostery between PRK2 and PDK1 and described an allosteric communication between the PIF-pocket and the active site of PRK2, both modulating the conformation of the ATP-binding site and the pseudosubstrate PKL-binding site. Our study highlights the allosteric modulation of the activity and the conformation of PRK2 in addition to the existence of at least two different complexes between PRK2 and its upstream kinase PDK1. Finally, the study highlights the potential for developing allosteric drugs to modulate PRK2 kinase conformations and catalytic activity.

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Knowledge of parasite-host interactions is essential for understanding factors associated with the ecology and evolution of both groups. Some aspects, such as host size and phylogeny, as well as parasite specificity, are significant predictors that help unveil the parasite-host relationship. Thus, the goals of this study were: (1) to describe parasite diversity in regions of the Atlantic Forest; (2) to analyze which host characteristics can influence parasite richness of anuran's parasite component community; and (3) to investigate if the prevalence of parasite infection is related to specificity metrics (ecological and phylogenetic), number of infected hosts and parasite's abundance. We identified 49 parasite taxa, classified into three phyla: Nematoda, Acanthocephala, and Platyhelminthes. Supporting the existing literature, our findings corroborate the positive relationship between host size and parasite richness, further emphasizing the significance of this predictor. Parasite prevalence in the host community is related to the number of infected host species and parasite abundance, but not to phylogenetic and ecological specificity indices. This shows that parasite prevalence is strongly associated with infection opportunity, host sampling effort, and high parasite abundance.

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Introducción. La enfermedad hepática grasa no alcohólica (EHGNA) es la hepatopatía crónica más común en el mundo, y en aproximadamente el 10 % de los casos progresará a cirrosis o a carcinoma hepatocelular. La presencia de fibrosis hepática es el mejor predictor de esta progresión, pero su diagnóstico mediante biopsia hepática es invasivo y con riesgo de complicaciones (alrededor del 2,5 %). Existen puntajes no invasivos que se han desarrollado y validado para estadificar la fibrosis, pero no conocemos su rendimiento en la población colombiana. El objetivo de este estudio fue evaluar el desempeño de los puntajes fibrosis-4 (FIB-4), la relación AST/ALT y el índice AST/plaquetas (APRI) para la detección de fibrosis avanzada en pacientes colombianos con EHGNA. Metodología. Estudio observacional tipo transversal de pacientes con EHGNA, que entre 2008 y 2022 tuvieran disponible el resultado de una biopsia hepática. Se hizo una descripción demográfica básica y se calculó el FIB-4, la relación AST/ALT y el APRI con los laboratorios más recientes previos al procedimiento. Posteriormente se calcularon valores de sensibilidad, especificidad, valores predictivos, razones de verosimilitud y área bajo la curva-característica operativa del receptor (AUC-ROC) para los puntos de corte evaluados previamente en la literatura. Resultados. Se incluyeron 176 pacientes, de los cuales el 14,3 % tenían fibrosis avanzada. El FIB-4 presentó el mejor rendimiento con un valor AUC-ROC de 0,74 para el punto de corte de 1,30 y 2,67. En segundo lugar, estuvo la relación AST/ALT con un valor AUC-ROC de 0,68 con el punto de corte de 0,8, y finalmente el APRI con valor AUC-ROC 0,62 con el punto de corte de 1. Conclusión. En la población analizada los tres puntajes tienen menor rendimiento diagnóstico comparado a los resultados reportados en Europa y Japón. El FIB-4 es el único que alcanza una AUC-ROC con rendimiento razonable, con la limitación que 27,4 % obtuvieron un resultado indeterminado.

Introduction. Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, with approximately 10% of cases progressing to cirrhosis or hepatocellular carcinoma. Liver fibrosis presence is the best predictor of this progression, yet its diagnosis through liver biopsy is invasive and poses risk of complications. Although non-invasive scoring systems have been developed and validated for fibrosis staging, their performance remains unexplored in the Colombian population. This study aims to assess the efficacy of the fibrosis-4 (FIB-4) score, AST/ALT ratio, and AST to platelet ratio index (APRI) in detecting advanced fibrosis among Colombian NAFLD patients. Methods. This cross-sectional observational study included NAFLD patients with available liver biopsy results from 2008 to 2022. Basic demographic characteristics were described, and FIB-4, APRI, and AST/ALT ratio were calculated using the latest laboratory data before the procedure. Subsequently, sensitivity, specificity, predictive values, likelihood ratios, and the area under the receiver operating characteristic curve (AUC-ROC) were computed for previously assessed cutoff points. Results. A total of 176 patients were included, among whom 14.3% had advanced fibrosis. FIB-4 demonstrated superior performance with an AUC-ROC value of 0.74 for cutoff points of 1.30 and 2.67. Following was the AST/ALT ratio with an AUC-ROC value of 0.68 for cutoff point of 0.8, and finally, APRI with an AUC-ROC of 0.62 for the cutoff point of 1. Conclusion. All three scores have lower diagnostic efficacy compared to results reported in Europe and Japan. FIB-4 is the only one that achieves an acceptable AUC-ROC performance with the limitation that an indeterminate result was obtained in 27,4% of the sample.

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Rhizobia are bacteria that form nitrogen-fixing nodules in legume plants. The sets of genes responsible for both nodulation and nitrogen fixation are carried in plasmids or genomic islands that are often mobile. Different strains within a species sometimes have different host specificities, while very similar symbiosis genes may be found in strains of different species. These specificity variants are known as symbiovars, and many of them have been given names, but there are no established guidelines for defining or naming them. Here, we discuss the requirements for guidelines to describe symbiovars, propose a set of guidelines, provide a list of all symbiovars for which descriptions have been published so far, and offer a mechanism to maintain a list in the future.

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BACKGROUND & AIMS: Tools for screening of nutrition risk in patients with cancer are usually validated against other screening instruments. Here with the performance of Malnutrition Screening Tool (MST) and Nutritional Screening Tool (NUTRISCORE) to identify the risk of malnutrition was assessed. A full nutritional evaluation and diagnosis following criteria from the Global Leadership Initiative of Malnutrition (GLIM) was the reference standard for the classification of malnutrition. METHODS: Diagnostic test prospective analysis of adult patients with a confirmed diagnosis of cancer. MST, NUTRISCORE and nutritional evaluation and diagnosis by GLIM criteria were independently performed within 24 h of admission to a 4th tier hospital in Bogotá, Colombia. RESULTS: From 439 patients the sensitivity and specificity of MST was 75% and 94% and of NUTRISCORE 45% and 97% respectively. The area under receiver operating characteristic (ROC) curves were 0.90 for MST and 0.85 for NUTRISCORE (p = 0.003). CONCLUSION: The MST showed a significantly better diagnostic performance over NUTRISCORE for detection of malnutrition risk at admission to hospital of patients with cancer.

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Permeability transition pore (PTP) opening dissipates ion and electron gradients across the internal mitochondrial membrane (IMM), including excess Ca2+ in the mitochondrial matrix. After opening, immediate PTP closure must follow to prevent outer membrane disruption, loss of cytochrome c, and eventual apoptosis. Flickering, defined as the rapid alternative opening/closing of PTP, has been reported in heart, which undergoes frequent, large variations in Ca2+. In contrast, in tissues that undergo depolarization events less often, such as the liver, PTP would not need to be as dynamic and thus these tissues would not be as resistant to stress. To evaluate this idea, it was decided to follow the reversibility of the permeability transition (PT) in isolated murine mitochondria from two different tissues: the very dynamic heart, and the liver, which suffers depolarizations less frequently. It was observed that in heart mitochondria PT remained reversible for longer periods and at higher Ca2+ loads than in liver mitochondria. In all cases, Ca2+ uptake was inhibited by ruthenium red and PT was delayed by Cyclosporine A. Characterization of this phenomenon included measuring the rate of oxygen consumption, organelle swelling and Ca2+ uptake and retention. Results strongly suggest that there are tissue-specific differences in PTP physiology, as it resists many more Ca2+ additions before opening in a highly active organ such as the heart than in an organ that seldom suffers Ca2+ loading, such as the liver.

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