Plasmon-enhanced fluorescence and electrochemical aptasensor for SARS-CoV-2 Spike protein detection.

In this work, we combined plasmon-enhanced fluorescence and electrochemical (PEF-EC) transduction mechanisms to realize a highly sensitive dual-transducer aptasensor. To implement two traducers in one biosensor, a novel large-scale nanoimprint lithography process was introduced to fabricate gold nanopit arrays (AuNpA) with unique fringe structures. Light transmitting through the AuNpA samples exhibited a surface plasmon polariton peak overlapping with the excitation peak of the C7 aptamer-associated fluorophore methylene blue (MB). We observed a five and seven-times higher average fluorescence intensity over the AuNpA and fringe structure, respectively, in comparison to a plane Au film. Furthermore, the MB fluorophore was simultaneously utilized as a redox probe for electrochemical investigations and is described here as a dual transduction label for the first time. The novel dual transducer system was deployed for the detection of SARS-CoV-2 Spike protein via a C7 aptamer in combination with a strand displacement protocol. The PEF transducer exhibited a detection range from 1 fg/mL to 10 ng/mL with a detection limit of 0.07 fg/mL, while the EC traducer showed an extended dynamic range from 1 fg/mL to 100 ng/mL with a detection limit of 0.15 fg/mL. This work provides insights into an easy-to-perform, large-scale fabrication process for nanostructures enabling plasmon-enhanced fluorescence, and the development of an advanced but universal aptasensor platform.

The impact of family factors and digital technologies on mental health in university students.

Introduction: A substantial body of research indicates an increasing prevalence of mental health issues among university students in a range of countries. A number of psychosocial factors have been put forward in the research literature as possible explanations for this persistent decline in psychological wellbeing in higher education. The present study focused on the role of family factors and the use of digital technologies by students. Methods: A replication study was conducted at the University of the Americas (Chile) based on a previous study on psychosocial factors of academic learning patterns and mental health of university students at the Complutense University of Madrid (UCM), Spain. A cross-sectional design was employed, using the same questionnaire, plus indicators of most frequently used digital technologies by the students. The questionnaire was administered online at the same time to all incoming students, gathering a sample of 4,523 students. A series of multiple regressions and ANOVAs was conducted to ascertain the extent to which family and digital factors could be identified as predictors of mental health indicators. Results: The most significant findings indicate that high levels of parental protection and control/discipline, and especially the high use of social media and smartphones, are particularly salient factors contributing to mental health problems in the learning process of higher education students. Discussion: The results suggest strategies to promote wellbeing, with a focus on the psychosocial diversity within an inclusive university community. Social and digital innovation, collective entrepreneurship, and participatory place-building may facilitate networks of artistic, cultural, ecological, and sports spaces to promote the sense of university community. A longitudinal follow-up on the same sample across academic years will reveal the extent to which these wellbeing initiatives are fruitful.

Ratiometric electrochemical aptasensor with strand displacement for insulin detection in blood samples.

BACKGROUND: Diabetes patients suffer either from insulin deficiency or resistance with a high risk of severe long-term complications, thus the quantitative assessment of insulin level is highly desired for diabetes surveillance and management. Utilizing insulin-capturing aptamers may facilitate the development of affordable biosensors however, their rigid G-quadruplex structures impair conformational changes of the aptamers and diminish the sensor signals. RESULTS: Here we report on a ratiometric, electrochemical insulin aptasensor which is achieved by hybridization of an insulin-capturing aptamer and a partially complementary ssDNA to break the rigid G-quadruplex structures. To improve the durability of the aptasensor, the capturing aptamer was immobilized on gold electrodes via two dithiol-phosphoramidite functional groups while methoxy-polyethylene glycol thiol was used as a blocking molecule. The exposure of the sensor to insulin-containing solutions induced the dissociation of the hybridized DNA accompanied by a conformational rearrangement of the capturing aptamer back into a G-quadruplex structure. The reliability of sensor readout was improved by the adoption of an AND logic gate utilizing anthraquinone and methylene blue redox probes associated to the aptamer and complementary strand, respectively. Our aptasensor possessed an improved detection limit of 0.15 nM in comparison to aptasensors without strand displacement. SIGNIFICANCE: The sensor was adapted for detection in real blood and is ready for future PoC diagnostics. The capability of monitoring the insulin level in an affordably manner can improve the treatment for an increasing number of patients in developed and developing nations. The utilization of low-cost and versatile aptamer receptors together with the engineering of ratiometric electrochemical signal recording has the potential to considerably advance the current insulin detection technology toward multi-analyte diabetes sensors.

Transcriptome Analysis in Mexican Adults with Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) represents around 25% of adult acute leukemias. Despite the increasing improvement in the survival rate of ALL patients during the last decade, the heterogeneous clinical and molecular features of this malignancy still represent a major challenge for treatment and achieving better outcomes. To identify aberrantly expressed genes in bone marrow (BM) samples from adults with ALL, transcriptomic analysis was performed using Affymetrix Human Transcriptome Array 2.0 (HTA 2.0). Differentially expressed genes (DEGs) (±2-fold change, p-value < 0.05, and FDR < 0.05) were detected using the Transcriptome Analysis Console. Gene Ontology (GO), Database for Annotation, Visualization, and Integrated Discovery (DAVID), and Ingenuity Pathway Analysis (IPA) were employed to identify gene function and define the enriched pathways of DEGs. The protein-protein interactions (PPIs) of DEGs were constructed. A total of 871 genes were differentially expressed, and DNTT, MYB, EBF1, SOX4, and ERG were the top five up-regulated genes. Meanwhile, the top five down-regulated genes were PTGS2, PPBP, ADGRE3, LUCAT1, and VCAN. An association between ERG, CDK6, and SOX4 expression levels and the probability of relapse and death was observed. Regulation of the immune system, immune response, cellular response to stimulus, as well as apoptosis signaling, inflammation mediated by chemokines and cytokines, and T cell activation were among the most altered biological processes and pathways, respectively. Transcriptome analysis of ALL in adults reveals a group of genes consistently associated with hematological malignancies and underscores their relevance in the development of ALL in adults.

Highly sensitive detection of malaria biomarker through matching channel and gate capacitance of integrated organic electrochemical transistors.

Organic electrochemical transistors (OECTs) possess versatile advantages for biochemical and electrophysiological applications due to electrochemical gating and ion-to-electron conversion capability. Although OECTs have been successfully applied for biochemical sensing, the effect of relative capacitance for specific sensing events is still unclear. In the present work, we design integrated interdigitated OECTs (iOECTs) with on-plane gold gate and different channel geometries for point-of-care diagnosis of malaria using aptamer as receptor. The transconductance of the iOECTs gated with micro-size gold electrodes decreased with increasing the channel thicknesses, especially for devices with large channel areas, which is inconsistent with devices gated by typical Ag/AgCl electrodes, attributing to the limited gating efficiency of the micro-size gate electrode. The capacitance of gate electrode was heavily suppressed by receptors but increased with the incubation of targets. In addition, the integrated iOECTs with thin channels exhibited superior sensitivity for malaria detection with the detection limit as low as 3.2 aM, much lower than their thick channel counterpart and other state-of-the-art biosensors. These deviations could be caused by the high relative capacitances, with respect to the gate and channel capacitance (Cg/Cch), resulting in a high gate potential drop over the organic channel and thus entirely gating on the thin channel device. These findings provide guidance to optimize the geometry of OECT devices with on-chip integrated gates and the fabrication of miniaturized OECTs for biosensing applications.

Truncated Electrochemical Aptasensor with Enhanced Antifouling Capability for Highly Sensitive Serotonin Detection.

Accurate determination of serotonin (ST) provides insight into neurological processes and enables applications in clinical diagnostics of brain diseases. Herein, we present an electrochemical aptasensor based on truncated DNA aptamers and a polyethylene glycol (PEG) molecule-functionalized sensing interface for highly sensitive and selective ST detection. The truncated aptamers have a small size and adopt a stable stem-loop configuration, which improves the accessibility of the aptamer for the analyte and enhances the sensitivity of the aptasensor. Upon target binding, these aptamers perform a conformational change, leading to a variation in the Faraday current of the redox tag, which was recorded by square wave voltammetry (SWV). Using PEG as blocking molecules minimizes nonspecific adsorption of other interfering molecules and thus endows an enhanced antifouling ability. The proposed electrochemical aptamer sensor showed a wide range of detection lasting from 0.1 nM to 1000 nM with a low limit of detection of 0.14 nM. Owing to the unique properties of aptamer receptors, the aptasensor also exhibits high selectivity and stability. Furthermore, with the reduced unspecific adsorption, assaying of ST in human serum and artificial cerebrospinal fluid (aCSF) showed excellent performance. The reported strategy of utilizing antifouling PEG describes a novel approach to building antifouling aptasensors and holds great potential for neurochemical investigations and clinical diagnosis.

A Combined Plasmonic and Electrochemical Aptasensor Based on Gold Nanopit Arrays for the Detection of Human Serum Albumin.

Electrochemical and optical platforms are commonly employed in designing biosensors. However, one signal readout can easily lead to inaccuracies due to the effect of nonstandard test procedures, different operators, and experimental environments. We have developed a dual-signal protocol that combined two transducer principles in one aptamer-based biosensor by simultaneously performing electrochemical- and extraordinary optical transmission (EOT)-based plasmonic detection using gold nanopit arrays (AuNpA). Compared with full hole structures, we found that nanopits, that did not fully penetrate the gold film, not only exhibited a better plasmonic bandwidth and refractive index sensitivity both in the finite-difference time-domain simulation and in experiments by shielding the gold/quartz mode but also enlarged the electrochemical active surface area. Therefore, the periodic non-fully penetrating AuNpA were modified with ferrocene-labeled human serum albumin aptamer receptors. The formation of the receptor layer and human serum albumin binding complex induced a conformational change, which resulted in variation in the electron transfer between the electro-active ferrocene units and the AuNpA surface. Simultaneously, the binding event caused a surface plasmon polaritons wavelength shift corresponding to a change in the surface refractive index. Interestingly, although both transducers recorded the same binding process, they led to different limits of detection, dynamic ranges, and sensitivities. The electrochemical transducer showed a dynamic detection range from 1 nM to 600 µM, while the optical transducer covered high concentrations from 100 µM to 600 µM. This study not only provides new insights into the design of plasmonic nanostructures but also potentially opens an exciting avenue for dual-signal disease diagnosis and point-of-care testing applications.

Compassion and decision fatigue among healthcare workers during COVID-19 pandemic in a Colombian sample.

Being compassionate and empathic while making rational decisions is expected from healthcare workers across different contexts. But the daily challenges that these workers face, aggravated by the recent COVID-19 crisis, can give rise to compassion and decision fatigue, which affects not only their ability to meet these expectations but has a significant negative impact on their wellbeing. Hence, it is vital to identify factors associated to their exhaustion. Here, we sought to describe levels of compassion and decision fatigue during the pandemic, and to identify factors related to these forms of exhaustion. We collected data using self-reported questionnaires to measure compassion fatigue, decision fatigue, and grit in five intervals from April to November, 2020 (N = 856). Our results showed a negative correlation between grit and compassion and decision fatigue. We also found that under the circumstances studied grit tends to be higher in technicians, nurses, other professionals (psychologists, social workers), and workers at the Emergency Room (ER), and lower in general practitioners. Compassion fatigue tend to be higher for technicians, whereas decision fatigue was lower for specialists, general practitioners, and technicians, and higher for those working at private hospitals.

MiRNAs in Hematopoiesis and Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common kind of pediatric cancer. Although the cure rates in ALL have significantly increased in developed countries, still 15-20% of patients relapse, with even higher rates in developing countries. The role of non-coding RNA genes as microRNAs (miRNAs) has gained interest from researchers in regard to improving our knowledge of the molecular mechanisms underlying ALL development, as well as identifying biomarkers with clinical relevance. Despite the wide heterogeneity reveled in miRNA studies in ALL, consistent findings give us confidence that miRNAs could be useful to discriminate between leukemia linages, immunophenotypes, molecular groups, high-risk-for-relapse groups, and poor/good responders to chemotherapy. For instance, miR-125b has been associated with prognosis and chemoresistance in ALL, miR-21 has an oncogenic role in lymphoid malignancies, and the miR-181 family can act either as a oncomiR or tumor suppressor in several hematological malignancies. However, few of these studies have explored the molecular interplay between miRNAs and their targeted genes. This review aims to state the different ways in which miRNAs could be involved in ALL and their clinical implications.

Is social origin, destination or mobility what matters to adult self-rated oral health?

OBJECTIVES: To evaluate the independent contributions of parental socioeconomic position (SEP), own SEP and social mobility to explain adult self-rated oral health. METHODS: Data from 6633 participants in the 1970 British Cohort Study were analysed. Parental SEP at the age of 10 years (social origin) and own SEP at the age of 46 years (social destination) were indicated by the 7-class National Statistics Socioeconomic Classification (NS-SEC). The study outcome was self-rated oral health (SROH) at the age of 46 years. Diagonal reference models (DRMs) were used to parse out the effects of parental SEP, own SEP and intergenerational mobility from childhood to middle adulthood, after adjusting for demographic characteristics (sex, ethnicity, country and area of residence). RESULTS: Overall, 23.1% of participants reported poor SROH. A baseline DRM, with no indicators of social mobility, showed that the contribution of own SEP to explain variations in SROH was higher than that of parental SEP. However, they became almost equal after indicators of social mobility were introduced. Downward mobility was associated with poor SROH (odds ratio: 1.24, 95% CI: 1.01-1.51), but upward mobility was not (1.01, 95% CI: 0.83-1.23). Also, short-range downward mobility and long-range downward mobility (moving 1 and 2+ social classes down in NS-SEC, respectively) were associated with poor SROH (1.26, 95% CI: 1.01-1.58 and 1.39, 95% CI: 1.06-1.83, respectively) whilst short-range upward mobility (1.04, 95% CI: 0.84-1.28) and long-range upward mobility (0.88, 95% CI: 0.67-1.14) were not. CONCLUSIONS: The contributions of parental and own SEP were similar once social mobility was accounted for. Only downward mobility was associated with poor SROH, with new evidence that long-range mobility was more strongly associated with poor SROH than short-range mobility.

Delineating charge and capacitance transduction in system-integrated graphene-based BioFETs used as aptasensors for malaria detection.

Despite significant eradication efforts, malaria remains a persistent infectious disease with high mortality due to the lack of efficient point-of-care (PoC) screening solutions required to manage low-density asymptomatic parasitemia. In response, we demonstrate a quantitative electrical biosensor based on system-integrated two-dimensional field-effect transistors (2DBioFETs) of reduced graphene oxide (rGO) as transducer for high sensitivity screening of the main malaria biomarker, Plasmodium falciparum lactate dehydrogenase (PfLDH). The 2DBioFETs were biofunctionalized with pyrene-modified 2008s aptamers as specific PfLDH receptors. While we systematically optimize biosensor interface for optimal performance, aptamer-protein transduction at 2DBioFETs is elucidated based on delineation of charge and capacitance in an updated analytical model for two-dimensional rGO/biofunctional layer/electrolyte (2DiBLE) interfaces. Our 2DBioFET-aptasensors display a limit-of-detection down to 0.78 fM (0.11 pg/mL), dynamic ranges over 9 orders of magnitude (subfemto to submicromolar), high sensitivity, and selectivity in human serum validating their diagnostic potential as rapid PoC tests for malarial management.

DNA aptamer selection for SARS-CoV-2 spike glycoprotein detection.

The rapid spread of SARS-CoV-2 infection throughout the world led to a global public health and economic crisis triggering an urgent need for the development of low-cost vaccines, therapies and high-throughput detection assays. In this work, we used a combination of Ideal-Filter Capillary Electrophoresis SELEX (IFCE-SELEX), Next Generation Sequencing (NGS) and binding assays to isolate and validate single-stranded DNA aptamers that can specifically recognize the SARS-CoV-2 Spike glycoprotein. Two selected non-competing DNA aptamers, C7 and C9 were successfully used as sensitive and specific biological recognition elements for the development of electrochemical and fluorescent aptasensors for the SARS-CoV-2 Spike glycoprotein with detection limits of 0.07 fM and 41.87 nM, respectively.

Hydrocarbon-based plastics: Progress and perspectives on consumption and biodegradation by insect larvae.

The obvious contrast between the remarkable durability and the high consumption of plastic products leads to the deposition of at least 100 million tons of plastics per year in nature. Since 2010, several studies have shown the potential of insect larvae to biodegrade different types of plastics, at higher rates than those reported for microorganisms. This review discusses a compilation of studies about the consumption and biodegradation of hydrocarbon-based plastics, particularly PE, PS, PP and PVC, by lepidopteran and coleopteran larvae. Insects of the Coleoptera order seem to have a better adaptation for PS biodegradation, while those of the Lepidoptera order can better biodegrade PE. Tenebrio molitor biomineralize PE and PS into CO2, and PVC into HCl; while Tenebrio obscurus and Zophobas atratus converts PE and PS into CO2, respectively. Plastic biodegradation by T. molitor has been shown to be dependent on microbiota, exception for PE. Similar PS and PE biodegradation profile has been shown for T. obscurus. PS, PP and PE biodegradation by Z. atratus is also reported to be microbial-dependent. For Galleria mellonella, microbial role on PE biodegradation is still controversial, but the PS metabolism was proved to be microbiota-independent. Advances in this field has stimulated new studies with other insect species, which need to be better explored. Uncovering and understanding the chemical processes behind the innate plastic biodegradation by insect larvae will open the perspective to new eco-friendly innovative biotechnological solutions for the challenge of plastic waste.

Electrochemical Immunosensor Using Electroactive Carbon Nanohorns for Signal Amplification for the Rapid Detection of Carcinoembryonic Antigen.

In this work, a novel sandwich-type electrochemical immunosensor was developed for the quantitative detection of the carcinoembryonic antigen, an important tumor marker in clinical tests. The capture antibodies were immobilized on the surface of a gold disk electrode, while detection antibodies were attached to redox-tagged single-walled carbon nanohorns/thionine/AuNPs. Both types of antibody immobilization were carried out through Au-S bonds using the novel photochemical immobilization technique that ensures control over the orientation of the antibodies. The electroactive SWCNH/Thi/AuNPs nanocomposite worked as a signal tag to carry out both the detection of carcinoembryonic antigen and the amplification of the detection signal. The current response was monitored by differential pulse voltammetry. A clear dependence of the thionine redox peak was observed as a function of the carcinoembryonic antigen concentration. A linear detection range from 0.001-200 ng/mL and a low detection limit of 0.1385 pg/mL were obtained for this immunoassay. The results showed that carbon nanohorns represent a promising matrix for signal amplification in sandwich-type electrochemical immune assays working as a conductive and binding matrix with easy and versatile modification routes to antibody and redox tag immobilization, which possesses great potential for clinical diagnostics of CEA and other biomarkers.

Perguntar para quê? quesito raça/cor no cadastro único para programas sociais / ¿ por qué preguntar? cuestión raza/color en el registro único de programas sociales / Why do ask for it? race/color question in the single registration for social programs

Resumo A partir da análise do preenchimento do quesito raça/cor do Cadastro Único para Programas Sociais do Governo Federal (CadÚnico), realizado por entrevistadoras sociais em um Centro de Referência de Assistência Social, este artigo objetiva discutir o tensionamento racial presente no campo da Política Nacional de Assistência Social (PNAS). Assumindo uma política investigativa pautada nos estudos da Ciência, Tecnologia e Sociedade e da Teoria Ator-Rede, utilizamos o registro de diários de campo como ferramenta à produção de dados sobre o referido preenchimento. Nesse percurso, assinalamos que o racismo brasileiro e as ambiguidades ligadas ao quesito raça/cor se atualizam no preenchimento do CadÚnico, implicando diferentes performances à produção da autodeclaração racial. Frente a isso, a compreensão das questões raciais nos processos socioterritoriais e subjetivos, que atravessam os serviços da PNAS, é fundamental ao desenvolvimento de práticas ao exercício da cidadania que não corroborem com manutenção da desigualdade racial brasileira.

Resumen A partir del análisis del llenado de la pregunta raza/color del Registro Único de Programas Sociales del Gobierno Federal (CadÚnico), realizado por entrevistadores sociales en un Centro de Referencia de Asistencia Social, este artículo tiene como objetivo discutir la tensión racial presente en la Política Nacional de Asistencia Social (PNAS). Asumiendo una política de investigación basada en los estudios de Ciencia, Tecnología y Sociedad y la Teoría Actor-Red, utilizamos el registro de diarios de campo como herramienta para la producción de datos sobre dicho relleno. De esta manera, señalamos que el racismo brasileño y las ambigüedades relacionadas con la raza/color se actualizan en el llenado del CadÚnico, lo que implica diferentes actuaciones en la producción de la autodeclaración racial. Así, la comprensión de las cuestiones raciales en los procesos socio-territoriales y subjetivos que atraviesan los servicios del PNAS es fundamental para el desarrollo de prácticas para el ejercicio de la ciudadanía que no corroboren el mantenimiento de la desigualdad racial en Brasil.

Abstract Based on the analysis of the filling out of the race/color question of the Federal Government Registry for the Social Programs (CadÚnico), carried out by social interviewers at a Social Assistance Reference Center, this article aims to discuss the racial tension present in the field of National Social Assistance Policy (PNAS). Assuming an investigative policy based on the studies of Science, Technology and Society and the Actor-Network Theory, we used field diaries registers as a tool for the production of data on the aforementioned filling. We point out that Brazilian racism and the ambiguities related to race/color are updated in filling out the CadÚnico, implying different performances in the production of racial self-declaration. In this view, the understanding of racial issues in the socio-territorial and subjective processes that cross the PNAS services is fundamental to the development of practices for the exercise of citizenship that do not corroborate the maintenance of Brazilian racial inequality.

An electrochemical aptamer-based biosensor targeting Plasmodium falciparum histidine-rich protein II for malaria diagnosis.

Malaria is an infectious disease caused by parasitic protozoans from the genus Plasmodium, with the species P. falciparum causing the highest number of deaths worldwide. Rapid diagnostic tests (RDTs) have become critical in the management of malaria, but current RDTs that detect P. falciparum are primarily antibody-based, which can have drawbacks in cost and robustness. Here, we report the development of an electrochemical aptamer-based (E-AB) biosensing alternative. Through selective evolution of ligands by exponential enrichment, we identify DNA aptamers that bind specifically to P. falciparum histidine-rich protein II (PfHRP2). The aptamer is modified with a methylene blue reporter and attached to a gold sensor surface for square-wave voltammetry interrogation. Through this method we are able to quantify PfHRP2 in human serum with an LOD of 3.73 nM. We further demonstrate the biosensor is stable in serum buffers and reusable for multiple detection rounds. These findings provide a promising alternative to conventional PfHRP2 detection for malaria diagnosis, while also expanding the capabilities of E-AB biosensors.

Avaliação do uso da Profilaxia Pré-Exposição ao HIV: coorte retrospectiva / Evaluation of the use of pre-exposure HIV prophylaxis: retrospective cohort / Evaluación del uso de profilaxis pre-exposición al VIH: cohorte retrospectiva

Objetivo: Identificar o perfil da população que buscou a Profilaxia Pré-Exposição ao HIV (PrEP) no Paraná e, entre os usuários da PrEP, avaliar modificações nos comportamentos de risco de adquirir infecções sexualmente transmissíveis (IST's), além de alterações nos exames laboratoriais de monitoramento. Métodos: Coorte retrospectiva com dados secundários obtidos do Sistema de Controle Logístico de Medicamentos acessados em 2018 e 2019. Investigou-se o perfil sociodemográfico da população que buscou a PrEP, de forma a correlacioná-lo aos segmentos prioritários para o uso do medicamento profilático. Entre os usuários, avaliaram-se dados comportamentais, testes diagnósticos para IST's, funções renal e hepática referentes a diferentes momentos no decorrer do uso. Os resultados comparados deram-se por meio dos testes Wilcoxon e Exato de Fisher. Resultados: 255 pessoas buscaram a PrEP. Predominaram-se o sexo masculino (92,28%), homossexuais (78,04%), de 20 a 39 anos (83,53%), brancos (71,76%), com 12 ou mais anos de estudo (74,90%). Para uso da PrEP elegeram-se 188 pessoas. Entre estas, durante o uso, observou-se aumento de práticas sexuais sem preservativo (p=0,012), diminuição no número de parceiros e do consumo de álcool (p=0,001), aumento da atividade de enzimas hepáticas ALT/AST (p=0,018), sem diferença no diagnóstico do HIV e outras IST's. Conclusão: Homens que fazem sexo com homens predominaram na busca pela profilaxia. Entre os usuários da PrEP, apesar do aumento de práticas sexuais desprotegidas, não houve aumento do diagnóstico de IST's no período do estudo. O medicamento da PrEP demonstrou bom perfil de segurança nos exames laboratoriais de seguimento.

Objective: To identify the profile of the population that sought HIV Pre-Exposure Prophylaxis (PrEP) in Paraná; and assess, among PrEP users, changes in risk behaviors for acquiring sexually transmitted infections (STIs) as well as changes in monitoring laboratory tests. Methods: Retrospective cohort with secondary data obtained from the Drug Logistics Control System accessed in 2018 and 2019. The sociodemographic profile of the population that sought PrEP was investigated to correlate it with priority segments for the use of prophylactic medication. Among users, behavioral data, diagnostic tests for STIs, kidney, and liver functions were evaluated at different times during use. The results were compared using the Wilcoxon and Fisher's Exact tests. Results: 255 people sought PrEP. Males predominated (92.28%), homosexuals (78.04%), from 20 to 39 years old (83.53%),white people (71.76%), with 12 or more years of schooling (74.90%). For the use of PrEP, 188 people were elected. Among them, during the usage, was noticed an increase in sexual practices without a condom (p=0.012), a decrease in the number of partners and alcohol consumption (p=0.001), an increase in the activity of liver enzymes ALT/AST (p=0.018), with no difference in the diagnosis of HIV and other STI's. Conclusion: Men who have sex with men predominated in the search for prophylaxis. Among PrEP users, despite the increase in unprotected sexual practices, there was no increase in the diagnosis of STIs during the study period; PrEP drugs showed a good safety profile in follow-up laboratory tests.

Objetivo: Identificar el perfil de la población que fue en busca de la Profilaxis pre-exposición al VIH (PrEP) en Paraná y, de entre los usuarios de la PrEP, evaluar los cambios de conducta de riesgo para tener infecciones de transmisión sexual (ITS) además de las alteraciones de las pruebas de laboratorios para el monitoreo. Métodos: Cohorte retrospectiva con datos secundarios del Sistema de Control Logístico de Medicamentos con acceso en 2018 y 2019. Se investigó el perfil sociodemográfico de la población que fue en busca de la PrEP, para correlacionarlo con los segmentos prioritarios para el uso del medicamento profiláctico. De los usuarios se ha evaluado los datos comportamentales, las pruebas de diagnósticos para las ITS, las funciones renales y hepática referente a distintos momentos durante el uso. Los resultados comparados se han dado a través de las pruebas de Wilcoxon y el Exacta de Fisher. Resultados: 255 personas han buscado la PrEP. Hubo el predominio para el sexo masculino (92,28%), homosexuales (78,04%), entre los 20 y 39 años (83,53%), blancos (71,76%), con 12 o más años de estudio (74,90%). Se há elegido 188 personas para el uso de la PrEP. De entre ellas, durante el uso, se observó el aumento de las prácticas sexuales sin condón (p=0,012), la disminución del número de compañeros y del consumo del alcohol (p=0,001), el aumento de la actividad de enzimas hepáticas ALT/AST (p=0,018), sin diferencia en el diagnóstico del VIH y de otras ITS. Conclusión: Los hombres que tienen sexo con hombres prevalecieron para la búsqueda de la profilaxis. De entre los usuarios de la PrEP, a pesar del aumento de las prácticas sexuales sin protección no hubo el aumento del diagnóstico de ITS en el período del estudio. El medicamento de la PrEP demostró un perfil bueno de seguridad en las pruebas de laboratorios de seguimiento.

Polyethylene glycol-mediated blocking and monolayer morphology of an electrochemical aptasensor for malaria biomarker detection in human serum.

Better approaches are critically needed for in situ point-of-care diagnostic biosensors that enable primary care physicians, or even individual patients, to directly analyze biological fluids without complicated sample pretreatments. Additional purification steps consume time, consume reagents, often require other equipment, and can introduce false-negative results. Biosensors have been modified with blocking molecules to reduce biofouling; however, the effectiveness relies on their chemical composition and morphology. Here, we used a polyethylene glycol film to suppress unspecific binding from human serum on an electrochemical malaria aptasensor. A detailed study of the variation of the chemical and morphological composition of the aptamer/polyethylene glycol mixed monolayer as a function of incubation time was conducted. Higher resistance to matrix biofouling was found for polyethylene glycol than for hydrophobic alkanethiol films. The best sensor performance was observed for intermediate polyethylene glycol immobilization times. With prolonged incubation, phase separation of aptamer, and polyethylene glycol molecules locally increased the aptamer density and thereby diminished the analyte binding capability. Remarkably, polyethylene glycols do not affect the aptasensor sensitivity but enhance the complex matrix tolerance, the dynamic range, and the limit of detection. Careful tuning of the blocking molecule immobilization is crucial to achieving high aptasensor performance and biofouling resistance.

Electrochemical dual-aptamer biosensors based on nanostructured multielectrode arrays for the detection of neuronal biomarkers.

Multielectrode arrays (MEAs) have been increasingly used for the development of biosensors due to their capability to record signals from multiple channels, fast mass transfer rates, and high spatial resolution. Alzheimer's disease (AD) is often associated with mitochondrial dysfunction, which is closely related to reduced levels of adenosine triphosphate (ATP). Therefore, simultaneous detection of ATP together with amyloid-ß oligomers (AßO), a reliable biomarker for AD, can potentially advance the early detection of Alzheimer's disease. In this work, a dual-aptamer modified MEA chip was developed that consists of microelectrodes modified with electrodeposited 3D nanostructures (3D-GMEs). Electrodeposition methods, deposition potential, and deposition time were systematically altered and the active surface areas as well as the electrode morphologies were characterized by cyclic voltammetry and scanning electron microscopy. The nanostructured microelectrodes were sequentially modified with AßO and ATP specific aptamer receptors. To achieve the modification of different aptamer receptors at different 3D-GMEs of the same MEA chip, electrochemical cleaning was applied to individual 3D-GMEs. Ferrocene labels were attached to the aptamer receptors to enable amperometric signaling after target-aptamer binding. The developed aptasensor showed a linear detection range from 1 pM to 200 nM for the detection of AßO and from 0.01 nM to 1000 nM for the detection of ATP. Finally, ATP and AßO were detected simultaneously in the same analyte solution by the same sensor chip, which could support the early detection of AD, provide comprehensive information about the health status of the patient, and be helpful for pathological studies of neurodegenerative diseases.

New quercetin-coated titanate nanotubes and their radiosensitization effect on human bladder cancer.

Interest in nanostructures such as titanate nanotubes (TNT) has grown notably in recent years due to their biocompatibility and economic viability, making them promising for application in the biomedical field. Quercetin (Qc) has shown great potential as a chemopreventive agent and has been widely studied for the treatment of diseases such as bladder cancer. Motivated by the possibilities of developing a new hybrid nanostructure with potential in biomedical applications, this study aimed to investigate the incorporation of quercetin in sodium (NaTNT) and zinc (ZnTNT) titanate nanotubes, and characterize the nanostructures formed. Qc release testing was also performed and cytotoxicity in Vero and T24 cell lines evaluated by the MTT assay. The effect of TNTs on T24 bladder cancer cell radiosensitivity was also assessed, using cell proliferation and a clonogenic assay. The TNT nanostructures were synthesized and characterized by FESEM, EDS, TEM, FTIR, XRD and TGA. The results showed that the nanostructures have a tubular structure and that the exchange of Na+ ions for Zn2+ and incorporation of quercetin did not alter this morphology. In addition, interaction between Zn and Qc increased the thermal stability of the nanostructures. The release test showed that maximum Qc delivery occurred after 24 h and the presence of Zn controlled its release. Biological assays indicated that the NaTNTQc and ZnTNTQc nanostructures decreased the viability of T24 cells after 48 h at high concentrations. Furthermore, the clonogenic assay showed that NaTNT, NaTNTQc, ZnTNT and ZnTNTQc combined with 5 Gy reduced the formation of polyclonal colonies of T24 cells after 48 h. The results suggest that the nanostructures synthesized in this study interfere in cell proliferation and can therefore be a powerful tool in the treatment of bladder cancer.