Physical properties of Scarpa's fascia.

Preservation of Scarpa's fascia has improved clinical outcomes in abdominoplasty procedures and in other body contour surgeries. However, the physical properties of Scarpa's fascia have not yet been described, and grafts are still underexplored. Fresh surgical specimens from five female patients subjected to classical abdominoplasty were dissected and analyzed. A grid was drawn on the fascia surface, dividing it into equal upper and lower halves; four Scarpa's fascia samples (30 × 10 mm) were collected from each half, 40 mm apart. The thickness was measured with a caliper. A strain/stress universal testing machine was used for mechanical tests. Twenty-five samples were obtained (nine from the upper half, 16 from the lower). The average thickness was 0.56 ± 0.11 mm. The average values for stretch, stress, strain, and Young's Modulus were, respectively, 1.436, 4.198 MPa, 43.6%, and 23.14 MPa. The upper half showed significantly greater thickness and strain values (p = 0.020 and p = 0.048; Student's t-test). The physical and biomechanical properties of Scarpa's fascia can make it a donor area for fascial grafts as an alternative to fascia lata, as it is always available and has minimal donor-site morbidity. Further studies are needed to validate this statement. It seems advantageous to use the lower half of the abdomen instead of the upper part as a donor site.

Comparison of two pharmacokinetic-pharmacodynamic models of rocuronium bromide during profound neuromuscular block: analysis of estimated and measured post-tetanic count effect.

BACKGROUND: Profound neuromuscular block (NMB) is important in surgeries where complete immobility is considered essential to improve tracheal intubation and surgical conditions. Rocuronium bromide is a commonly used NMB agent. This work describes a noninvasive approach for estimation of post-tetanic count (PTC) based on two pharmacokinetic (PK) models, the Saldien and the De Haes models. The aim was to investigate the rocuronium bromide PK-pharmacodynamic (PD) relationship in estimating the PTC effect during profound NMB. METHODS: In this prospective, non-randomised, observational study, an induction bolus of rocuronium bromide was administered followed by continuous infusion for maintenance of a PTC of 1-2. measured every 3 min. Measurements were analysed as discrete categorical data and by applying the nonlinear mixed-effect modelling approach. Performance of the selected models was evaluated through simulation model-based diagnostics, further assessing the precision of the parameter estimates and the performance of the models at the individual level. RESULTS: Data from 30 adult patients undergoing elective abdominal or neurosurgical procedures were included. Post-tetanic count response profiles during rocuronium bromide infusion were successfully characterised using the population PD analysis. The models showed a good performance for all PTC categories, albeit with a moderate over-prediction of PTC >6. CONCLUSIONS: Our findings indicate that using plasma concentrations of rocuronium bromide estimated with either of the two models, combined with a PD model, provides equal model performance when predicting PTC. These promising results may provide an important advance in guiding rocuronium bromide administration when profound NMB in routine clinical practice is desired.

Detecting bone lesions in the emergency room with medical infrared thermography.

INTRODUCTION: Low- to high-energy impact trauma may cause from small fissures up to extended bone losses, which can be classified as closed or opened injuries (when they are visible at a naked eye). OBJECTIVE: The aim of this study was to investigate the feasibility of clinical diagnosis of bone trauma through medical infrared thermography, in a hospital emergency room. METHODS: Forty-five patients with suspected diagnosis of bone fracture were evaluated by means of medical infrared images, and the data correlated with the gold standard radiographic images, in the anteroposterior, lateral, and oblique views, at the orthopedic emergency department. The control group consisted of thermal images of the contralateral reference limb of the volunteers themselves. Data were acquired with a medical grade infrared camera in the regions of interest (ROIs) of leg, hand, forearm, clavicle, foot, and ankle. RESULTS: In all patients evaluated with a diagnosis of bone fracture, the mean temperature of the affected limb showed a positive difference greater than 0.9 °C (towards the contralateral), indicating the exact location of the bone trauma according, while the areas diagnosed with reduced blood supply, showed a mean temperature with a negative variation. CONCLUSION: Clinical evaluation using infrared imaging indicates a high applicability potential as a tool to support quick diagnosis of bone fractures in patients with acute orthopedic trauma in an emergency medical setting. The thermal results showed important physiological data related to vascularization of the bone fracture and areas adjacent to the trauma well correlated to radiographic examinations.

Lock-In Thermal Test Simulation, Influence, and Optimum Cycle Period for Infrared Thermal Testing in Non-Destructive Testing.

Lock-in thermal tests (LTTs) are one of the best ways to detect defects in composite materials. The parameter that most affects their performance is the cycle period of the stimulation wave. Its influence on the amplitude-phase results was determined by performing various numeric simulations and laboratory tests. The laboratory tests were used to infer part of the simulation parameters, namely the input and output heat, corresponding to the stimulation and natural convection. The simulations and the analysis of their results focus on the heat flow inside the sample and the manner they change for different geometries. This was performed for poly(methyl methacrylate (PMMA) and carbon fiber-reinforced polymers (CFRPs). The simulation of these materials was also used to create prediction surfaces and equations. These predict the amplitude and phase for a sample with a thickness l and a cycle period. These new findings were validated with new laboratory tests and two new samples. These validated the prediction surfaces and equations and can now be used as a reference for future works and industrial applications.

Skin temperature response to thermal stimulus in patients with hyperhidrosis: A comparative study.

Primary hyperhidrosis (HH), the excessive sweating exceeding physiological demand, has been associated to a complex dysfunction of the autonomic nervous system which may explain the disfunction in sweating but may also cause unrevealed alterations in skin blood flow regulation. In fact, HH patients present a sympathetic over-function with less reflex bradycardia in response to the Valsalva maneuver and higher sympathetic skin responses. We aimed to identify response patterns to room thermal stimulus in HH patients compared to a control group in order to investigate putative differences in blood flow assuming that skin temperature in glabrous (non-hairy) areas reflect the sympathetic tone in arteriovenous anastomoses (AVAs). Infrared thermography images were obtained from a cohort of patients diagnosed with HH, followed at a hospital pediatric surgical department and to a sex- and age-matched control group of patients admitted for other surgical procedures. With the participants in Fowler's position, a set of 3 images were captured simultaneously and 44 regions of interest were analyzed, distributed on the palms of the hands, soles of the feet, axilla, and inner canthus. After an acclimatization period at 20 °C, the room temperature was increased to 24, 28 and 32 °C to obtain similar sets of thermograms. A total of 37 patients with HH and 16 participants in the control group were included in the study. At baseline (20 °C), body core temperature (measured in the inner canthus) was significantly higher in the HH patients compared to the controls (p = 0.019 and p = 0.003 in right and left inner canthi, respectively), without any significant differences in the other thermograms. When room temperature was increased, differences in core temperature disappeared, while differences appeared in axilla and palms of the hands with HH patients presenting significantly lower temperature at the three thermal stimulus stages. Patients with HH presented a lower thermoregulatory response when submitted to room temperature increase, which may reflect a vasomotor sympathetic over-function in AVAs.

Electromyographic assessment of blink reflex throughout the transition from responsiveness to unresponsiveness during induction with propofol and remifentanil.

General anesthesia is a reversible drug-induced state of altered arousal characterized by loss of responsiveness due to brainstem inactivation. Precise identification of the moment in which responsiveness is lost during the induction of general anesthesia is extremely important to provide information regarding an individual's anesthetic requirements and help intraoperative drug titration. To characterize the transition from responsiveness to unresponsiveness more objectively, we studied neurophysiologic-derived parameters of electromyographic records of electrically evoked blink reflex as a means of identifying the precise moment of loss of responsiveness. Twenty-five patients received a slow infusion of propofol until loss of corneal reflex while successive blink reflexes were elicited and recorded every 6 s. The level of anesthesia was assessed using an adapted version of the Richmond Agitation-Sedation Scale. Different variables of the blink reflex components were calculated and compared to the adapted version of the Richmond Agitation-Sedation score and the estimated effect-site propofol concentration. Baselines of the blink reflex responses were similar to those in literature. After propofol infusion started, the most susceptible component of the blink reflex to propofol was R2 (EC50 = 1.358 (95% CI 1.321, 1.396) µg/mL) and the most resistant was R1 (EC50 = 3.025 (95% CI 2.960, 3.090) µg/mL). Most of the patients (24 out of 25) lost the R1 component when they were still responsive to shaking and shouting and corneal reflex could be elicited clinically (time = 102.48 ± 33.00 s). Habituation was present in R2 but not in R1. The R1 component of the blink reflex was found to have a strong correlation with the adapted version of the Richmond Agitation-Sedation Scale, with amplitude correlating better than areas (ρ = - 0.721 (0.123) versus ρ = - 0.688 (0.165)). We found a strong correlation between the R1 component with the estimated propofol effect-site concentration, with amplitude correlating better than areas (ρ = - 0.838 (0.113) versus ρ = - 0.823 (0.153)) and between the clinical scale and the propofol concentration (ρ = 0.856 (0.060)). The area and amplitude of the R1 component showed to be indicators of predicting different levels of anesthesia (Pk = 0.672 (0.183) versus Pk = 0.709 (0.134)) and these are connected to the propofol concentrations (Pk = 0.593 (0.10)). Our results suggest that electrically evoked blink reflex could be used during the induction of anesthesia as a surrogate of the Richmond Agitation-Sedation Scale to provide an objective endpoint as far as a - 4. At this point, at the moment of loss of R1, the propofol infusion may be stopped, as overshooting increases slightly the effect-site concentration afterward and eventually reaching loss of responsiveness. If the desired target is not achieved, the infusion can then be resumed.

Performance of blink reflex in patients during anesthesia induction with propofol and remifentanil: prediction probabilities and multinomial logistic analysis.

BACKGROUND: The amount of propofol needed to induce loss of responsiveness varied widely among patients, and they usually required less than the initial dose recommended by the drug package inserts. Identifying precisely the moment of loss of responsiveness will determine the amount of propofol each patient needs. Currently, methods to decide the exact moment of loss of responsiveness are based on subjective analysis, and the monitors that use objective methods fail in precision. Based on previous studies, we believe that the blink reflex can be useful to characterize, more objectively, the transition from responsiveness to unresponsiveness. The purpose of this study is to investigate the relation between the electrically evoked blink reflex and the level of sedation/anesthesia measured with an adapted version of the Richmond Agitation-Sedation Scale, during the induction phase of general anesthesia with propofol and remifentanil. Adding the blink reflex to other variables may allow a more objective assessment of the exact moment of loss of responsiveness and a more personalized approach to anesthesia induction. RESULTS: The electromyographic-derived features proved to be good predictors to estimate the different levels of sedation/anesthesia. The results of the multinomial analysis showed a reasonable performance of the model, explaining almost 70% of the adapted Richmond Agitation-Sedation Scale variance. The overall predictive accuracy for the model was 73.6%, suggesting that it is useful to predict loss of responsiveness. CONCLUSIONS: Our developed model was based on the information of the electromyographic-derived features from the blink reflex responses. It was able to predict the drug effect in patients undergoing general anesthesia, which can be helpful for the anesthesiologists to reduce the overwhelming variability observed between patients and avoid many cases of overdosing and associated risks. Despite this, future research is needed to account for variabilities in the clinical response of the patients and with the interactions between propofol and remifentanil. Nevertheless, a method that could allow for an automatic prediction/detection of loss of responsiveness is a step forward for personalized medicine.

Craniofacial morphology of wind and string instrument players: a cephalometric study.

BACKGROUND: Playing an instrument may promote a parafunctional behavior within the cranio-cervical-mandibular-complex with unknown repercussions. The aim of this study was to find any association between the dental inter-arch relationship and the practice of a wind or string instrument. METHODS: A sample of 77 musicians, divided in two groups of wind (n = 50) and string instrumentalists (n = 27), had a lateral cephalogram taken to compare six cephalometric parameters following the Rickett's analysis (maxilla position, mandible position, facial type, skeletal class, upper incisor and lower incisor inclination). The Fisher test was performed to compare, with a 95% statistical confidence, if both groups have similar frequency distributions for each cephalometric parameter. RESULTS: No statistical differences were found for the maxilla position, mandible position, facial type, skeletal class and upper incisor inclination. Statistical differences were found for the lower incisor inclination (p = 0.011). CONCLUSIONS: Playing a wind instrument showed to have little orthopaedic influence at the craniofacial morphology, on contrary it may influence the lower incisor inclination with its osseous base.

Infrared thermography of the crânio-cervico-mandibular complex in wind and string instrumentalists.

PURPOSE: Musculoskeletal disorders can be common in wind and string instrumentalists. The musical gesture technique associated to musical performance can promote an asymmetrical isometric contraction with the hyperactivity of specific muscular groups and the overload of articular surfaces which can cause discomfort or pain. The aim of this investigation was to assess specific anatomical regions of interest within the cranio-cervico-mandibular complex in order to determine and evaluate the presence of muscular hyperactivity associated to musical performance. METHODS: An infrared imaging camera, FLIR®, was used to record the regions of interest in wind (n = 48) and string instrumentalists (n = 29). Bilateral temperature differences were considered as thermal asymmetries with a conventional threshold of 0.3 ºC to distinguish pathological from healthy states. The regions of interest (ROI) were the anterior triangle of the neck, the sternocleidomastoid and trapezius muscles regarding the postural and stabilizing muscles of the head and neck. On the orofacial region, the anatomical sites were the anterior temporal muscle, the masseter muscle and the temporomandibular joint. A Pearson chi-square test was performed to compare the assessed areas. RESULTS: Between 30-37% of all participants showed ROI in an asymmetric pattern. The most affected sites were the temporal muscle and the TMJ for both groups. The anterior triangle of the neck showed statistical differences (p = 0.044) between string and wind instrumentalists, while the temporal (p = 0.034) and trapezius muscle (p = 0.028) when comparing large and small mouthpieces of brass instruments. Although female participants showed a higher prevalence of asymmetrical patterns regarding the ROI, no statistical differences were found between genders. CONCLUSIONS: Infrared thermography exhibited significant differences between wind and string instruments within the CCMC. Regarding the issue of occupational health in performing arts, it is an advantage being able to quantify asymmetrical patterns sites of the CCMC to understand the underlying physiological responses to repetitive movements, overloading and muscular hyperactivity that occur during musical performance.

The role of AI classifiers in skin cancer images.

BACKGROUND: The use of different imaging modalities to assist in skin cancer diagnosis is a common practice in clinical scenarios. Different features representative of the lesion under evaluation can be retrieved from image analysis and processing. However, the integration and understanding of these additional parameters can be a challenging task for physicians, so artificial intelligence (AI) methods can be implemented to assist in this process. This bibliographic research was performed with the goal of assessing the current applications of AI algorithms as an assistive tool in skin cancer diagnosis, based on information retrieved from different imaging modalities. MATERIALS AND METHODS: The bibliography databases ISI Web of Science, PubMed and Scopus were used for the literature search, with the combination of keywords: skin cancer, skin neoplasm, imaging and classification methods. RESULTS: The search resulted in 526 publications, which underwent a screening process, considering the established eligibility criteria. After screening, only 65 were qualified for revision. CONCLUSION: Different imaging modalities have already been coupled with AI methods, particularly dermoscopy for melanoma recognition. Learners based on support vector machines seem to be the preferred option. Future work should focus on image analysis, processing stages and image fusion assuring the best possible classification outcome.

Biomedical musculoskeletal applications of infrared thermal imaging on arm and forearm: A systematic review.

Infrared thermal imaging (IRT) has been a target of research for biomedical musculoskeletal applications, due to the possible association of the physiological data that it provides, through skin temperature measurement, with pathological states. The aim of this systematic review is to acquaint the outcomes of the biomedical application of IRT in arm and forearm evaluation and its future perspectives of research. During the literature review, 926 articles were identified using the search engines PubMed and Scopus, and 10 articles were retrieved from other sources. After screening the abstracts and applying the eligibility criteria on those which were fully accessible, 33 articles were included in the review. It can be observed that IRT has the potential to provide physiological information on the arm and forearm, showing potential to serve as an aid in various pathologies and health situations. Future studies and challenges are identified and proposed, facilitating the improvement and acceptance of the application of IRT in the assessment of arm and forearm' health status.

Dimethylaminoparthenolide reduces the incidence of dysplasia and ameliorates a wasting syndrome in HPV16-transgenic mice.

The nuclear factor kappa light chain enhancer of activated B cells (NF-κB) has been implicated in the progression of cancers induced by high-risk human papillomaviruses (HPV). In cancer patients, NF-κB is also thought to drive a chronic systemic inflammatory status, leading to cachexia. This study addressed the ability of dimethylaminoparthenolide (DMAPT), a water-soluble NF-κB inhibitor, to block the development of HPV-induced lesions and wasting syndrome in HPV16-transgenic mice. Mice received DMAPT orally (100 mg/kg/day), once a day, for 6 consecutive weeks. Body weight was monitored weekly along with food and water intake. After 6 weeks the animals were submitted to a grip strength test and sacrificed for specimen collection. Skin samples were analyzed histologically and for expression of NF-κB-regulated genes Bcl2 and Bcl2l1. Gastrocnemius muscles were weighted and analyzed for expression of NF-κB subunits p50, p52, p65, and Rel-B. DMAPT reduced the incidence of epidermal dysplasia (18.2% versus 33.3% in HPV16+/- untreated mice). This was associated with reduced expression of Bcl2 and Bcl2l1 (p = .0003 and p = .0014, respectively) and reduced neutrophilic infiltration (p = .0339). Treated mice also showed partially preserved bodyweight and strength, which were independent of the expression levels of NF-κB subunits in skeletal muscle.These results suggest that NF-κB inhibition may be a valid strategy against HPV-induced lesions in vivo and warrant further preclinical tests particularly in the set of combination therapies. In addition, the data may support the use of DMAPT to prevent wasting syndrome.

Are there any solutions for improving the cleft area hygiene in patients with cleft lip and palate? A systematic review.

OBJECTIVE: Children with cleft lip and palate (CLP) present high incidence of oral health problems, namely those associated with the accumulation of dental plaque. The objective of this systematic review was to verify if there is any solution to improve the hygiene of the cleft area. MATERIALS AND METHODS: A structured systematic review was performed based on articles published in several electronic databases: PubMed, Web of Science, Cochrane Library and Scopus in the last 20 years. The MeSH terms used were cleft lip, palate, harelip, oral hygiene and toothbrush. RESULTS: From 270 potentially relevant articles, 39 articles were selected, corresponding to a total of 3226 CLP patients and 914 matched controls. The selected studies exhibited great heterogeneity regarding the type of the study, study population (average range 0 -49 years old; sampling sizes 15-400 CLP patients), evaluation periods, reported variables and oral hygiene routines. Consensual outcomes were the presence of high plaque indexes, high prevalence of dental caries and worse oral hygiene patterns in CLP patients. Additionally, poor education in oral health and low motivation to integrate regular hygiene routines in the daily family life were also evident. CONCLUSION: There is a clear need to improve the oral hygiene care of CLP children, but few studies were focused on specific preventive approaches. Development of devices especially designed to the hygiene of the cleft area and implementation of standardized prevention and control programmes targeting education, motivation and compliance would contribute to improve oral health in CLP children.

How light absorption modifies the radiative force on a microparticle in optical tweezers.

Reflection and refraction of light can be used to trap small dielectric particles in the geometrical optics regime. Absorption of light is usually neglected in theoretical calculations, but it is known that it occurs in the optical trapping of semi-transparent particles. Here, we propose a generalization of Ashkin's model for the radiative force exerted on a spherical bead, including the contribution due to attenuation/absorption of light in the bulk of the particle. We discuss in detail the balance between refraction, reflection, and absorption for different optical parameters and particle sizes. Our findings contribute to the understanding of optical trapping of light-absorbing particles and may be used to predict whenever absorption is important in real experiments.

Antero-cervical thermophysiological characterization of obstructive sleep apnea patients.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is characterized by upper airway inflammation. The aim of this study was to characterize thermal profile of the antero-cervical region in OSAS patients through medical thermal imaging and to compare the respective subjects with non-OSAS individuals. METHODS: Image capture followed the Glamorgan Protocol. A dynamic thermographic examination of the anterior cervical region (at baseline and after a cold stimulus) was conducted in 26 patients diagnosed with overnight polysomnography (PSG). PSG results stratified the subjects into OSAS and non-OSAS groups and their thermograms were compared. RESULTS: Eleven non-OSAS and 15 OSAS subjects were evaluated. Antero-cervical right side (RS) temperature was higher in OSAS group at baseline (p = 0.014). Right side index (RSI) temperature-the difference between RS and submental region, considered as control-was lower in OSAS subjects at baseline (p = 0.020) and 10 min after the cold stimuli was applied (p = 0.008), indicating higher absolute temperatures in this group. Left side index (LSI) was also lower at 10 min in OSAS group (p = 0.021). Statistical correlation was found between apnea-hypopnea index and RS at baseline (r = 0.424, p = 0.031) and at 10 min (r = 0.403, p = 0.041) and RSI at baseline (r = - 0.458, p = 0.019) and 10 min after cold provocation was applied (r = - 0.435, p = 0.025). CONCLUSIONS: OSAS patients have shown higher antero-cervical temperatures compared with non-OSAS counterparts and temperature was associated with severity of the condition. Medical thermography may be a suitable tool in the setting of OSAS suspicion.

Oral hygiene of children with cleft lip and palate: Efficacy of the cleft toothbrush - A designed add-on to regular toothbrushes.

BACKGROUND: The anatomical and morphological alterations associated with cleft lip and palate (CLP) favour the buildup of dental plaque. AIM: To assess the efficacy of a new add-on to regular toothbrush-the Cleft Toothbrush, in removing the dental plaque of CLP patients, compared to a regular toothbrush. DESIGN: Forty-five children with CLP were randomly organized into two groups: A (n = 26, 2-6 years old) and B (n = 19, 7-12 years old). They were evaluated at days 0, 15, 30, and 60. After brushing their teeth with a regular toothbrush or with the Cleft Toothbrush, the dental plaque was recorded using an adapted Plaque Index (aPI). Data analyses were performed in IBM SPSS(c) , and all statistic inference comparisons were made using non-parametric tests. RESULTS: In the first 15 days, children used a new regular toothbrush and aPI-C (teeth adjacent to the cleft) was recorded. The Cleft Toothbrush, used by all children from day 15 to day 30, showed high efficacy in removing dental plaque in the cleft area, evidenced by significantly lower aPI-C values, compared to those observed with the regular toothbrush (P < 0.001). When given free option of brushing technique, from day 30 to day 60, most of the children (38 out of 45) chose the Cleft Toothbrush. CONCLUSIONS: The Cleft Toothbrush showed high efficacy in removing dental plaque in the cleft area, and presented high level of acceptance by parents and children, compared to a regular toothbrush. This is expected to improve the health status of the local adjacent tissues, a requirement for their rehabilitation.

Combined Acquisition Method of Image and Signal Technique (CAMIST) for Assessment of Temporomandibular Disorders in Performing Arts Medicine.

OBJECTIVE: This pilot study investigated the morphological and functional aspects of an English horn player, who presented at a dental appointment with temporomandibular disorder (TMD), using the "combined acquisition method of image and signal technique" (CAMIST) in the diagnosis. METHODS: Cephalometric analysis was obtained after carrying out three lateral cephalograms using a standardized radiographic technique. The first one was taken with the teeth in the normal occlusion and the lips relaxed, the second with the oboe embouchure, and the last was performed with the English horn. To understand the pressures involved during the embouchure and musical performance of the English horn and oboe, a system was developed using force sensors placed on the double-reed mouthpiece. Finally, infrared imaging was used to better understand the anatomy-physiology of specific structures of the cranio-cervico-mandibular complex. RESULTS: Cephalometry of the musician showed more significant changes in the retrusion of the mandibular pogonion. The embouchure pressures measured during musical practice showed that the English horn induced a higher pressure on the lower lip than on the upper, while the inverse happened with the oboe. Thermography confirmed the painful site on the left temporomandibular joint (TMJ), and this was also observed in the muscle tenderness/discomfort on the right superficial masseter by the differential temperature of these areas. CONCLUSION: Techniques such as lateral teleradiography, infrared imaging, and force sensors can be useful screening tools with added value for the diagnosis of TMDs in performing artists.

Cloning, expression and purification of the human Islet Amyloid Polypeptide (hIAPP) from Escherichia coli.

Type II diabetes is characterized by deposition of the hormone human Islet Amyloid Polypeptide (hIAPP). Formation of hIAPP amyloid fibrils and aggregates is considered to be responsible for pancreatic ß-cell losses. Therefore, insight into the structure of hIAPP in the solid-state and in solution is of fundamental importance in order to better understand the action of small molecules, which can potentially dissolve protein aggregates and modulate cell toxicity. So far, no procedure has been described that allows to obtain the native human IAPP peptide at high yields. We present here a cloning, expression and purification protocol that permits the production of 2.5 and 3mg of native peptide per liter of minimal and LB medium, respectively. In the construct, hIAPP is fused to a chitin binding domain (CBD). The CBD is subsequently cleaved off making use of intein splicing reaction which yield amidation of the C-terminus. The N-terminus contains a solubilization domain which is cleaved by V8 protease, avoiding additional residues at the N-terminus. The correct formation of the disulfide bond is achieved by oxidation with H2O2.

A biosensor based on magnetoelastic waves for detection of antibodies in human plasma for COVID-19 serodiagnosis.

This study proposes a new efficient wireless biosensor based on magnetoelastic waves for antibody detection in human plasma, aiming at the serological diagnosis of COVID-19. The biosensor underwent functionalization with the N antigen - nucleocapsid phosphoprotein of the SARS-CoV-2 virus. Validation analyses by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting (WB), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) microanalysis and micro-Raman spectroscopy confirmed the selectivity and effective surface functionalization of the biosensor. The research successfully obtained, expressed and purified the recombinant antigen, while plasma samples from COVID-19 positive and negative patients were applied to test the performance of the biosensor. A performance comparison with the enzyme-linked immunosorbent assays (ELISA) method revealed equivalent diagnostic capacity. These results indicate the robustness of the biosensor in reliably differentiating between positive and negative samples, highlighting its potential as an efficient and low-cost tool for the serological diagnosis of COVID-19. In addition to being fast to execute and having the potential for automation in large-scale diagnostic studies, the biosensor fills a significant gap in existing SARS-CoV-2 detection approaches.