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1.
Small ; 20(13): e2306167, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37963854

RESUMO

Colloidal metal nanoparticles dispersions are commonly used to create functional printed electronic devices and they typically require time-, energy- and equipment-consuming post-treatments to improve their electrical and mechanical properties. Traditional methods, e.g. thermal, UV/IR, and microwave treatments, limit the substrate options and may require expensive equipment, not available in all the laboratories. Moreover, these processes also cause the collapse of the film (nano)pores and interstices, limiting or impeding its nanostructuration. Finding a simple approach to obtain complex nanostructured materials with minimal post-treatments remains a challenge. In this study, a new sintering method for gold nanoparticle inks that called as "click sintering" has been reported. The method uses a catalytic reaction to enhance and tune the nanostructuration of the film while sintering the metallic nanoparticles, without requiring any cumbersome post-treatment. This results in a conductive and electroactive nanoporous thin film, whose properties can be tuned by the conditions of the reaction, i.e., concentration of the reagent and time. Therefore, this study presents a novel and innovative one-step approach to simultaneously sinter gold nanoparticles films and create functional nanostructures, directly and easily, introducing a new concept of real-time treatment with possible applications in the fields of flexible electronics, biosensing, energy, and catalysis.

2.
Anal Bioanal Chem ; 414(2): 759-789, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34432105

RESUMO

Metabolomics refers to the large-scale detection, quantification, and analysis of small molecules (metabolites) in biological media. Although metabolomics, alone or combined with other omics data, has already demonstrated its relevance for patient stratification in the frame of research projects and clinical studies, much remains to be done to move this approach to the clinical practice. This is especially true in the perspective of being applied to personalized/precision medicine, which aims at stratifying patients according to their risk of developing diseases, and tailoring medical treatments of patients according to individual characteristics in order to improve their efficacy and limit their toxicity. In this review article, we discuss the main challenges linked to analytical chemistry that need to be addressed to foster the implementation of metabolomics in the clinics and the use of the data produced by this approach in personalized medicine. First of all, there are already well-known issues related to untargeted metabolomics workflows at the levels of data production (lack of standardization), metabolite identification (small proportion of annotated features and identified metabolites), and data processing (from automatic detection of features to multi-omic data integration) that hamper the inter-operability and reusability of metabolomics data. Furthermore, the outputs of metabolomics workflows are complex molecular signatures of few tens of metabolites, often with small abundance variations, and obtained with expensive laboratory equipment. It is thus necessary to simplify these molecular signatures so that they can be produced and used in the field. This last point, which is still poorly addressed by the metabolomics community, may be crucial in a near future with the increased availability of molecular signatures of medical relevance and the increased societal demand for participatory medicine.


Assuntos
Metabolômica/métodos , Testes Imediatos , Medicina de Precisão , Biomarcadores/metabolismo , Química Analítica , Humanos
3.
J Neuroeng Rehabil ; 13(1): 58, 2016 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-27305944

RESUMO

BACKGROUND: Robotic neurorehabilitation aims at promoting the recovery of lost function after neurological injury by leveraging strategies of motor learning. One important aspect of the rehabilitation process is the improvement of muscle coordination patterns, which can be drastically altered after stroke. However, it is not fully understood if and how robotic therapy can address these deficits. The aim of our study was to find how muscle coordination, analyzed from the perspective of motor modules, could change during motor adaptation to a dynamic environment generated by a haptic interface. METHODS: In our experiment we employed the traditional paradigm of exposure to a viscous force field to subjects that grasped the handle of an actuated joystick during a reaching movement (participants moved directly forward and back by 30 c m). EMG signals of ten muscles of the tested arm were recorded. We extracted motor modules from the pooled EMG data of all subjects and analyzed the muscle coordination patterns. RESULTS: We found that the participants reacted by using a coordination strategy that could be explained by a change in the activation of motor modules used during free motion and by two complementary modules. These complementary modules aggregated changes in muscle coordination, and evolved throughout the experiment eventually maintaining a comparable structure until the late phase of re-adaptation. CONCLUSIONS: This result suggests that motor adaptation induced by the interaction with a robotic device can lead to changes in the muscle coordination patterns of the subject.


Assuntos
Adaptação Fisiológica/fisiologia , Músculo Esquelético/fisiologia , Desempenho Psicomotor/fisiologia , Robótica/métodos , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Movimento/fisiologia
4.
Sensors (Basel) ; 16(10)2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27706085

RESUMO

The use of haptic devices in the rehabilitation of impaired limbs has become rather popular, given the proven effectiveness in promoting recovery. In a standard framework, such devices are used in rehabilitation centers, where patients interact with virtual tasks, presented on a screen. To track their sessions, kinematic/dynamic parameters or performance scores are recorded. However, as Internet access is now available at almost every home and in order to reduce the hospitalization time of the patient, the idea of doing rehabilitation at home is gaining wide consent. Medical care programs can be synchronized with the home rehabilitation device; patient data can be sent to the central server that could redirect to the therapist laptop (tele-healthcare). The controversial issue is that the recorded data do not actually represent the clinical conditions of the patients according to the medical assessment scales, forcing them to frequently undergo clinical tests at the hospital. To respond to this demand, we propose the use of a bilateral master/slave haptic system that could allow the clinician, who interacts with the master, to assess remotely and in real time the clinical conditions of the patient that uses the home rehabilitation device as the slave. In this paper, we describe a proof of concept to highlight the main issues of such an application, limited to one degree of freedom, and to the measure of the stiffness and range of motion of the hand.


Assuntos
Tecnologia de Sensoriamento Remoto/métodos , Desenho de Equipamento , Humanos , Amplitude de Movimento Articular/fisiologia , Telemedicina , Interface Usuário-Computador
5.
Mult Scler ; 21(11): 1385-95, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26438306

RESUMO

BACKGROUND: Recent studies identified > 100 non-HLA (human leukocyte antigen) multiple sclerosis (MS) susceptibility variants in Northern European populations, but their role in Southern Europeans is largely unexplored. OBJECTIVE: We aimed to investigate the cumulative impact of those variants in two Mediterranean populations: Continental Italians and Sardinians. METHODS: We calculated four weighted Genetic Risk Scores (wGRS), using up to 102 non-HLA MS risk variants and 5 HLA MS susceptibility markers in 1691 patients and 2194 controls from continental Italy; and 2861 patients and 3034 controls from Sardinia. We then assessed the differences between populations using Nagelkerke's R(2) and the area under the Receiver Operating Characteristic (ROC) curves. RESULTS: As expected, the genetic burden (mean wGRS value) was significantly higher in MS patients than in controls, in both populations. Of note, the burden was significantly higher in Sardinians. Conversely, the proportion of variability explained and the predictive power were significantly higher in continental Italians. Notably, within the Sardinian patients, we also observed a significantly higher burden of non-HLA variants in individuals who do not carry HLA risk alleles. CONCLUSIONS: The observed differences in MS genetic burden between the two Mediterranean populations highlight the need for more genetic studies in South Europeans, to further expand the knowledge of MS genetics.


Assuntos
Predisposição Genética para Doença , Antígenos HLA/genética , Esclerose Múltipla/etnologia , Esclerose Múltipla/genética , Biomarcadores , Genótipo , Humanos , Itália/etnologia , Polimorfismo de Nucleotídeo Único , Risco
6.
Biosens Bioelectron ; 260: 116421, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838572

RESUMO

Wearable technologies are becoming pervasive in our society, and their development continues to accelerate the untapped potential of continuous and ubiquitous sensing, coupled with big data analysis and interpretation, has only just begun to unfold. However, existing wearable devices are still bulky (mainly due to batteries and electronics) and have suboptimal skin contact. In this work, we propose a novel approach based on a sensor network produced through inkjet printing of nanofunctional inks onto a semipermeable substrate. This network enables real-time monitoring of critical physiological parameters, including temperature, humidity, and muscle contraction. Remarkably, our system operates under battery-free and wireless near-field communication (NFC) technology for data readout via smartphones. Moreover, two of the three sensors were integrated onto a naturally adhesive bioinspired membrane. This membrane, developed using an eco-friendly, high-throughput process, draws inspiration from the remarkable adhesive properties of mussel-inspired molecules. The resulting ultra-conformable membrane adheres effortlessly to the skin, ensuring reliable and continuous data collection. The urgency of effective monitoring systems cannot be overstated, especially in the context of rising heat stroke incidents attributed to climate change and high-risk occupations. Heat stroke manifests as elevated skin temperature, lack of sweating, and seizures. Swift intervention is crucial to prevent progression to coma or fatality. Therefore, our proposed system holds immense promise for the monitoring of these parameters on the field, benefiting both the general population and high-risk workers, such as firefighters.


Assuntos
Técnicas Biossensoriais , Bivalves , Golpe de Calor , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Humanos , Tecnologia sem Fio/instrumentação , Técnicas Biossensoriais/instrumentação , Animais , Golpe de Calor/prevenção & controle , Bivalves/química , Adesivos/química , Membranas Artificiais , Desenho de Equipamento , Smartphone
7.
Biosens Bioelectron ; 250: 116079, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38295580

RESUMO

Following the global COVID-19 pandemic triggered by SARS-CoV-2, the need for rapid, specific and cost-effective point-of-care diagnostic solutions remains paramount. Even though COVID-19 is no longer a public health emergency, the disease still poses a global threat leading to deaths, and it continues to change with the risk of new variants emerging causing a new surge in cases and deaths. Here, we address the urgent need for rapid, cost-effective and point-of-care diagnostic solutions for SARS-CoV-2. We propose a multiplexed DNA-based sensing platform that utilizes inkjet-printed nanostructured gold electrodes and an inkjet-printed battery-free near-field communication (NFC) potentiostat for the simultaneous quantitative detection of two SARS-CoV-2 genes, the ORF1ab and the N gene. The detection strategy based on the formation of an RNA-DNA sandwich structure leads to a highly specific electrochemical output. The inkjet-printed nanostructured gold electrodes providing a large surface area enable efficient binding and increase the sensitivity. The inkjet-printed battery-free NFC potentiostat enables rapid measurements and real-time data analysis via a smartphone application, making the platform accessible and portable. With the advantages of speed (5 min), simplicity, sensitivity (low pM range, ∼450% signal gain) and cost-effectiveness, the proposed platform is a promising alternative for point-of-care diagnostics and high-throughput analysis that complements the COVID-19 diagnostic toolkit.


Assuntos
Técnicas Biossensoriais , COVID-19 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Pandemias , Eletrodos , DNA/genética , Ouro/química , Técnicas Eletroquímicas
8.
Biosens Bioelectron ; 258: 116340, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38718633

RESUMO

The escalating global incidence of infectious diseases caused by pathogenic bacteria, especially in developing countries, emphasises the urgent need for rapid and portable pathogen detection devices. This study introduces a sensitive and specific electrochemical biosensing platform utilising cost-effective electrodes fabricated by inkjet-printing gold and silver nanoparticles on a plastic substrate. The biosensor exploits the CRISPR/Cas12a system for detecting a specific DNA sequence selected from the genome of the target pathogen. Upon detection, the trans-activity of Cas12a/gRNA is triggered, leading to the cleavage of rationally designed single-strand DNA reporters (linear and hairpin) labelled with methylene blue (ssDNA-MB) and bound to the electrode surface. In principle, this sensing mechanism can be adapted to any bacterium by choosing a proper guide RNA to target a specific sequence of its DNA. The biosensor's performance was assessed for two representative pathogens (a Gram-negative, Escherichia coli, and a Gram-positive, Staphylococcus aureus), and results obtained with inkjet-printed gold electrodes were compared with those obtained by commercial screen-printed gold electrodes. Our results show that the use of inkjet-printed nanostructured gold electrodes, which provide a large surface area, in combination with the use of hairpin reporters containing a poly-T loop can increase the sensitivity of the assay corresponding to a signal variation of 86%. DNA targets amplified from various clinically isolated bacteria, have been tested and demonstrate the potential of the proposed platform for point-of-need applications.


Assuntos
Técnicas Biossensoriais , Sistemas CRISPR-Cas , Escherichia coli , Ouro , Nanopartículas Metálicas , Staphylococcus aureus , Técnicas Biossensoriais/instrumentação , Ouro/química , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/genética , Escherichia coli/isolamento & purificação , Escherichia coli/genética , Nanopartículas Metálicas/química , Prata/química , DNA Bacteriano/análise , DNA Bacteriano/genética , Técnicas Eletroquímicas/métodos , Humanos , Nanoestruturas/química , DNA de Cadeia Simples/química , Eletrodos , Impressão , Proteínas de Bactérias/genética , Endodesoxirribonucleases , Proteínas Associadas a CRISPR
9.
Green Chem ; 25(4): 1647-1657, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36824602

RESUMO

Heavy metal pollutants are of great concern to environmental monitoring due to their potent toxicity. Electrochemical detection, one of the main techniques, is hindered by the mutual interferences of various heavy metal ions in practical use. In particular, the sensitivity of carbon electrodes to Cd2+ ions (one of the most toxic heavy metals) is often overshadowed by some heavy metals (e.g. Pb2+ and Cu2+). To mitigate interference, metallic particles/films (e.g. Hg, Au, Bi, and Sn) typically need to be embedded in the carbon electrodes. However, these additional metallic materials may face issues of secondary pollution and unsustainability. In this study, a metal-free and sustainable nanomaterial, namely cysteamine covalently functionalized graphene (GSH), was found to lead to a 6-fold boost in the Cd2+ sensitivity of the screen-printed carbon electrode (SPCE), while the sensitivities to Pb2+ and Cu2+ were not influenced in simultaneous detection. The selective enhancement could be attributed to the grafted thiols on GSH sheets with good affinity to Cd2+ ions based on Pearson's hard and soft acid and base principle. More intriguingly, the GSH-modified SPCE (GSH-SPCE) featured high reusability with extended cycling times (23 times), surpassing the state-of-art SPCEs modified by non-covalently functionalized graphene derivatives. Last, the GSH-SPCE was validated in tap water.

10.
Artigo em Inglês | MEDLINE | ID: mdl-36786303

RESUMO

Graphene-based materials are of interest in electrochemical biosensing due to their unique properties, such as high surface areas, unique electrochemical properties, and biocompatibility. However, the scalable production of graphene electrodes remains a challenge; it is typically slow, expensive, and inefficient. Herein, we reported a simple, fast, and maskless method for large-scale, low-cost reduced graphene oxide electrode fabrication; using direct writing (laser scribing and inkjet printing) coupled with a stamp-transferring method. In this process, graphene oxide is simultaneously reduced and patterned with a laser, before being press-stamped onto polyester sheets. The transferred electrodes were characterized by SEM, XPS, Raman, and electrochemical methods. The biosensing utility of the electrodes was demonstrated by developing an electrochemical test for Escherichia coli. These biosensors exhibited a wide dynamic range (917-2.1 × 107 CFU/mL) of low limits of detection (283 CFU/mL) using just 5 µL of sample. The test was also verified in spiked artificial urine, and the sensor was integrated into a portable wireless system driven and measured by a smartphone. This work demonstrates the potential to use these biosensors for real-world, point-of-care applications. Hypothetically, the devices are suitable for the detection of other pathogenic bacteria.

11.
Neuroepidemiology ; 39(1): 19-26, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22777403

RESUMO

BACKGROUND: Sardinia, insular Italy, represents a particular epidemiological setting to investigate polyfactorial diseases, by virtue of its phylogeny and geographic isolation over time and of a well-established network of health operators and information systems. We present the first prevalence study of epilepsy conducted on a large Sardinian population by means of multiple source ascertainment. METHODS: Cases were ascertained in the province of Sassari (population of 333,576) for the period between January 1, 2000 and December 31, 2008 based on records from (a) the District Center for Epilepsy, (b) the District Health Information System Unit, and (c) the neurologists practicing within the National Health System. RESULTS: The total crude prevalence of active epilepsy on December 31, 2007 was 6.62 per 1,000 (95% CI 5.3-7.9), 6.51 in men (95% CI 5.4-7.6), and 6.73 in women (95% CI 5.7-7.7). The highest prevalence (8.78 per 1,000) was estimated in the elderly (≥65 years). 50.5% were symptomatic epilepsies. Of these, over 50% were secondary to cerebrovascular disorders in the elderly. CONCLUSIONS: The epidemiological behavior of prevalence of active epilepsy in Sardinia appears to be in line with that of other developed countries, despite the role that population-specific genetic and environmental factors exert in modulating the risk for other neurological diseases. The action of (exogenous) factors commonly distributed in western populations, also influencing, at least partially, the epidemiological patterns of epilepsy in Sardinians, should not be ruled out.


Assuntos
Epilepsia/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Epilepsia/etiologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
12.
Exp Brain Res ; 221(1): 33-41, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22733310

RESUMO

The arm movement control system often relies on visual feedback to drive motor adaptation and to help specify desired trajectories. Here we studied whether kinematic errors that were indicated with auditory feedback could be used to control reaching in a way comparable with when vision was available. We randomized twenty healthy adult subjects to receive either visual or auditory feedback of their movement trajectory error with respect to a line as they performed timed reaching movements while holding a robotic joystick. We delivered auditory feedback using spatialized pink noise, the loudness and location of which reflected kinematic error. After a baseline period, we unexpectedly perturbed the reaching trajectories using a perpendicular viscous force field applied by the joystick. Subjects adapted to the force field as well with auditory feedback as they did with visual feedback and exhibited comparable after effects when the force field was removed. When we changed the reference trajectory to be a trapezoid instead of a line, subjects shifted their trajectories by about the same amount with either auditory or visual feedback of error. These results indicate that arm motor networks can readily incorporate auditory feedback to alter internal models and desired trajectories, a finding with implications for the organization of the arm motor control adaptation system as well as sensory substitution and motor training technologies.


Assuntos
Adaptação Psicológica/fisiologia , Meio Ambiente , Retroalimentação Sensorial/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Estimulação Acústica , Adulto , Análise de Variância , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
13.
J Neuroeng Rehabil ; 9: 79, 2012 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-23046683

RESUMO

BACKGROUND: This paper presents the results of a set of experiments in which we used continuous auditory feedback to augment motor training exercises. This feedback modality is mostly underexploited in current robotic rehabilitation systems, which usually implement only very basic auditory interfaces. Our hypothesis is that properly designed continuous auditory feedback could be used to represent temporal and spatial information that could in turn, improve performance and motor learning. METHODS: We implemented three different experiments on healthy subjects, who were asked to track a target on a screen by moving an input device (controller) with their hand. Different visual and auditory feedback modalities were envisaged. The first experiment investigated whether continuous task-related auditory feedback can help improve performance to a greater extent than error-related audio feedback, or visual feedback alone. In the second experiment we used sensory substitution to compare different types of auditory feedback with equivalent visual feedback, in order to find out whether mapping the same information on a different sensory channel (the visual channel) yielded comparable effects with those gained in the first experiment. The final experiment applied a continuously changing visuomotor transformation between the controller and the screen and mapped kinematic information, computed in either coordinate system (controller or video), to the audio channel, in order to investigate which information was more relevant to the user. RESULTS: Task-related audio feedback significantly improved performance with respect to visual feedback alone, whilst error-related feedback did not. Secondly, performance in audio tasks was significantly better with respect to the equivalent sensory-substituted visual tasks. Finally, with respect to visual feedback alone, video-task-related sound feedback decreased the tracking error during the learning of a novel visuomotor perturbation, whereas controller-task-related sound feedback did not. This result was particularly interesting, as the subjects relied more on auditory augmentation of the visualized target motion (which was altered with respect to arm motion by the visuomotor perturbation), rather than on sound feedback provided in the controller space, i.e., information directly related to the effective target motion of their arm. CONCLUSIONS: Our results indicate that auditory augmentation of visual feedback can be beneficial during the execution of upper limb movement exercises. In particular, we found that continuous task-related information provided through sound, in addition to visual feedback can improve not only performance but also the learning of a novel visuomotor perturbation. However, error-related information provided through sound did not improve performance and negatively affected learning in the presence of the visuomotor perturbation.


Assuntos
Estimulação Acústica , Retroalimentação Psicológica/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Algoritmos , Fenômenos Biomecânicos , Sistemas Computacionais , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
14.
Expert Rev Med Devices ; 19(5): 405-421, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35786139

RESUMO

INTRODUCTION: Stroke is the leading cause of long-term disability in developed countries. Due to population aging, the number of people requiring rehabilitation after stroke is going to rise in the coming decades. Robot-mediated neurorehabilitation has the potential to improve clinical outcomes of rehabilitation treatments. A statistical analysis of the literature aims to focus on the main trend of this topic. AREAS COVERED: A bibliometric survey on post-stroke robotic rehabilitation was performed through a database collection of scientific publications in the field of rehabilitation robotics. By covering the last 20 years, 17,429 sources were collected. Relevant patterns and statistics concerning the main research areas were analyzed. Leading journals and conferences which publish and disseminate knowledge in the field were identified. A detailed nomenclature study was carried out. The time trends of the research field were captured. Opinions and predictions of future trends that are expected to shape the near future of the field were discussed. EXPERT OPINION: Data analysis reveals the continuous expansion of the research field over the last two decades, which is expected to rise considerably in near future. More attention will be paid to the lower limbs rehabilitation and disease/design specific applications in early-stage patients.


Assuntos
Reabilitação Neurológica , Robótica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Bibliometria , Humanos , Extremidade Superior
15.
Biosens Bioelectron ; 202: 114005, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35078142

RESUMO

Wearables are becoming pervasive in our society, but they are still mainly based on physical sensors with just few optical and electrochemical exceptions. Sweat, amongst other body fluids, is easily and non-invasively accessible, abundant, and relatively poor of interfering species. The biomarkers of interest in sweat space from ions and small molecules to whole organisms. Heavy metals have been found being biomarkers of several diseases and pathological conditions. Copper in particular is correlated to Wilson's disease and liver cirrhosis among others. Nevertheless, several issues such as sampling conditions, sweat rate normalization, reliable continuous monitoring, and typically expensive fabrication methods still needs to be addressed in sweat analysis with wearables. Herein, we propose a fully printed wearable microfluidic nanosensor with an integrated wireless smartphone-based readout. Our system can easily be applied on the skin and actively stimulate perspiration, normalizing the heavy metals concentration with respect to the volume of the sample and the sweat rate. The system has a limit of detection of 396 ppb, a linear range up to 2500 ppb and a sensitivity of 2.3 nA/ppb.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Técnicas Biossensoriais/métodos , Cobre/análise , Atenção à Saúde , Microfluídica , Suor/química
16.
Biosens Bioelectron ; 195: 113628, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34543917

RESUMO

With the increased demand for beef in emerging markets, the development of quality-control diagnostics that are fast, cheap and easy to handle is essential. Especially where beef must be free from pork residues, due to religious, cultural or allergic reasons, the availability of such diagnostic tools is crucial. In this work, we report a label-free impedimetric genosensor for the sensitive detection of pork residues in meat, by leveraging the biosensing capabilities of graphene acid - a densely and selectively functionalized graphene derivative. A single stranded DNA probe, specific for the pork mitochondrial genome, was immobilized onto carbon screen-printed electrodes modified with graphene acid. It was demonstrated that graphene acid improved the charge transport properties of the electrode, following a simple and rapid electrode modification and detection protocol. Using non-faradaic electrochemical impedance spectroscopy, which does not require any electrochemical indicators or redox pairs, the detection of pork residues in beef was achieved in less than 45 min (including sample preparation), with a limit of detection of 9% w/w pork content in beef samples. Importantly, the sample did not need to be purified or amplified, and the biosensor retained its performance properties unchanged for at least 4 weeks. This set of features places the present pork DNA sensor among the most attractive for further development and commercialization. Furthermore, it paves the way for the development of sensitive and selective point-of-need sensing devices for label-free, fast, simple and reliable monitoring of meat purity.


Assuntos
Técnicas Biossensoriais , Grafite , Animais , Bovinos , DNA , Técnicas Eletroquímicas , Eletrodos , Carne
17.
Biosens Bioelectron ; 196: 113737, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740116

RESUMO

Simplicity is one of the key feature for the spread of any successful technological product. Here, a method for rapid and low-cost fabrication of electrochemical biosensors is presented. This "plug, print & play" method involves inkjet-printing even in an office-like environment, without the need of highly specialized expertise or equipment, guaranteeing an ultra-fast idea to (scaled) prototype production time. The printed biosensors can be connected to a smartphone through its audio input for their impedance readout, demonstrating the validity of the system for point-of-care biosensing. Proper electrodes layout guarantees high sensitivity and is validated by finite element simulations. The introduction of a passivation method (wax printing) allowed to complete the devices fabrication process, increasing their sensitivity. Indeed, the wax allowed reducing the interference related to the parasitic currents flowing through the permeable coating of the employed substrates, which was used for the chemical sintering, thus avoiding the common thermal treatment after printing. As a case study, we used the devices to develop an electrochemical aptamer-based sensor for the rapid detection of neutrophil gelatinase-associated lipocalin (NGAL) in urine - a clinically important marker of acute kidney injury. The aptasensor platform is capable of detecting clinically relevant concentrations of NGAL with a simple and rapid smartphone readout. The developed technology may be extended in the future to continuous monitoring, taking advantage of its flexibility to integrate it in tubes, or to other diagnostic applications where cost/efficiency and rapidity of the research, development and implementation of point of care devices is a must.


Assuntos
Técnicas Biossensoriais , Impedância Elétrica , Eletrodos , Smartphone , Tecnologia
18.
J Neuroeng Rehabil ; 8: 21, 2011 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-21513561

RESUMO

BACKGROUND: Practicing arm and gait movements with robotic assistance after neurologic injury can help patients improve their movement ability, but patients sometimes reduce their effort during training in response to the assistance. Reduced effort has been hypothesized to diminish clinical outcomes of robotic training. To better understand patient slacking, we studied the role of visual distraction and auditory feedback in modulating patient effort during a common robot-assisted tracking task. METHODS: Fourteen participants with chronic left hemiparesis from stroke, five control participants with chronic right hemiparesis and fourteen non-impaired healthy control participants, tracked a visual target with their arms while receiving adaptive assistance from a robotic arm exoskeleton. We compared four practice conditions: the baseline tracking task alone; tracking while also performing a visual distracter task; tracking with the visual distracter and sound feedback; and tracking with sound feedback. For the distracter task, symbols were randomly displayed in the corners of the computer screen, and the participants were instructed to click a mouse button when a target symbol appeared. The sound feedback consisted of a repeating beep, with the frequency of repetition made to increase with increasing tracking error. RESULTS: Participants with stroke halved their effort and doubled their tracking error when performing the visual distracter task with their left hemiparetic arm. With sound feedback, however, these participants increased their effort and decreased their tracking error close to their baseline levels, while also performing the distracter task successfully. These effects were significantly smaller for the participants who used their non-paretic arm and for the participants without stroke. CONCLUSIONS: Visual distraction decreased participants effort during a standard robot-assisted movement training task. This effect was greater for the hemiparetic arm, suggesting that the increased demands associated with controlling an affected arm make the motor system more prone to slack when distracted. Providing an alternate sensory channel for feedback, i.e., auditory feedback of tracking error, enabled the participants to simultaneously perform the tracking task and distracter task effectively. Thus, incorporating real-time auditory feedback of performance errors might improve clinical outcomes of robotic therapy systems.


Assuntos
Estimulação Acústica , Retroalimentação Psicológica/fisiologia , Estimulação Luminosa , Robótica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/psicologia , Adulto , Idoso , Braço/fisiologia , Feminino , Marcha/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Paresia/etiologia , Paresia/reabilitação , Prática Psicológica , Desempenho Psicomotor/fisiologia , Caracteres Sexuais , Interface Usuário-Computador
19.
Sci Rep ; 11(1): 14938, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294822

RESUMO

The use of surface electromyography (sEMG) is rapidly spreading, from robotic prostheses and muscle computer interfaces to rehabilitation devices controlled by residual muscular activities. In this context, sEMG-based gesture recognition plays an enabling role in controlling prosthetics and devices in real-life settings. Our work aimed at developing a low-cost, print-and-play platform to acquire and analyse sEMG signals that can be arranged in a fully customized way, depending on the application and the users' needs. We produced 8-channel sEMG matrices to measure the muscular activity of the forearm using innovative nanoparticle-based inks to print the sensors embedded into each matrix using a commercial inkjet printer. Then, we acquired the multi-channel sEMG data from 12 participants while repeatedly performing twelve standard finger movements (six extensions and six flexions). Our results showed that inkjet printing-based sEMG signals ensured significant similarity values across repetitions in every participant, a large enough difference between movements (dissimilarity index above 0.2), and an overall classification accuracy of 93-95% for flexion and extension, respectively.

20.
Adv Mater ; 33(18): e2006104, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33719117

RESUMO

Monitoring of the human microbiome is an emerging area of diagnostics for personalized medicine. Here, the potential of different nanomaterials and nanobiosensing technologies is reviewed for the development of novel diagnostic devices for the detection and measurement of microbiome-related biomarkers. Moreover, the current and future landscape of microbiome-based diagnostics is defined by exploring the advantages and disadvantages of current nanotechnology-based approaches, especially in the context of developing point-of-care (PoC) devices that would meet the international guidelines known as REASSURED (Real-time connectivity; Ease of specimen collection; Affordability; Sensitivity; Specificity; User-friendliness; Rapid & robust operation; Equipment-free; and Deliverability). Finally, the strategies of the latest international scientific consortia working in this field are analyzed, the current microbiome diagnostics market are reported and the principal ethical, legal, and societal issues related to microbiome R&D and innovation are discussed.


Assuntos
Microbiota , Nanomedicina/métodos , Humanos , Nanomedicina/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito
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