Hugo Alexandre Ferreira

University of Lisbon | UL · Faculty of Science

Three-dimensional (3D) printing is becoming a promising tool for drug delivery, tissue modeling, fabrication, and regeneration. This chapter discusses the most recent advances and the state-of-the-art applications of 3D printing and bioprinting, including the use of models, scaffolds, biopapers, and bioinks, in nanoneurosciences and neuroscience in...

Introduction Mental health resilience is crucial to professional wellbeing and productivity, being that 57% of company employees are reporting burnout. Additionally, early-stage preventive mental health interventions are not common, and typically employees only have access to mid-stage professional care. Objectives The aim of this project is to pr...

Skin microvasculature provides a window to study both systemic and local physiology. In vascular medicine, various challengers such reactive hyperemia, hypoxia or hyperoxia, and heat, have been used to study function and search for potential clinical biomarkers. A positive relationship between increased skin temperature and skin perfusion has been...

Reactive hyperemia (RH) and the post occlusive reactive hyperemia (PORH) are known to assess vascular function in vivo and referred as useful prognostic tools in vascular medicine. However, its translation to clinical practice is poor due to important unsolved inconsistencies. Our group has been studying the adaptive responses following RH. Here we...

Our study examines how laser dazzling affects human performance, specifically accuracy and reaction times, using a laser dazzling shooting simulator at the Royal Military Academy, Belgium. The research assesses the performance degradation under laser dazzling in a simple, baseline scene, including different target contrasts and the use of laser eye...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective: This work explores Hall effect sensing paired with a permanent magnet, in the context of pulmonary rehabilitation exercise training. Methods: Experimental evaluation was performed considering as reference the gold-standard of respiratory m...

Over the last decade, Transcranial Direct Current Stimulation (tDCS) has been applied not only to modulate local cortical activation, but also to address communication between functionally-related brain areas. Stimulation protocols based on simple two-electrode placements are being replaced by multi-electrode montages to target intra- and inter-hem...

Purpose The use of insects as food is a proposed solution for the increased demand for food worldwide, but it lacks acceptance because of restrictive emotional factors. This article aims to understand better customers' emotions’ role in considering and consuming insect-based food. Design/methodology/approach To assess their acceptance, an experime...

Magnetic resonance imaging (MRI) plays an important role in assessing early brain development and injury in neonates. When using an automated volumetric analysis, brain tissue segmentation is necessary, preceded by brain extraction (BE) to remove non-brain tissue. BE remains challenging in neonatal brain MRI, and despite the existence of several me...

Background Radiomics features obtained from anatomical magnetic resonance imaging (MRI) have been showing potential as biomarkers for the diagnosis of Alzheimer’s disease (AD). Nevertheless, little is known about how accelerated parallel MRI acquisitions impact such features and their potential in diagnosing AD. Therefore, this study aimed to compa...

Erythromelalgia (EM) is a rare disease, which is still poorly characterized. In the present paper, we compared the hand perfusion of one female EM patient, under challenges, with a healthy control group. Using a laser Doppler flowmeter (LDF) with an integrated thermal probe, measurements were taken in both hands at rest (Phase I) and after two sepa...

Objective: In the context of pulmonary rehabilitation exercise training, wearable real-time monitoring of respiratory patterns may represent a valuable tool in increasing accessibility to treatment, as well as expanding the opportunities of treatment automation and locomotor-respiratory coupling. This work explores Hall effect sensing, paired with...

Objective: In the context of pulmonary rehabilitation exercise training, wearable real-time monitoring of respiratory patterns may represent a valuable tool in increasing accessibility to treatment, as well as expanding the opportunities of treatment automation and locomotor-respiratory coupling. This work explores Hall effect sensing, paired with...

Aptamers, short strands of either DNA, RNA, or peptides, known for their exceptional specificity and high binding affinity to target molecules, are providing significant advancements in the field of health. When seamlessly integrated into biosensor platforms, aptamers give rise to aptasensors, unlocking a new dimension in point-of-care diagnostics...

After the COVID-19 pandemic, reports using lung ultrasonography (LUS) rose worldwide, together with the knowledge of the biophysics behind lung artifacts and the convenience of monitoring lung diseases over time. Interstitial lung diseases may develop insidiously, and the differential diagnosis remains challenging even using high-resolution thoraci...

Ultrasound (US) imaging is used in the diagnosis and monitoring of COVID-19 and breast cancer. The presence of Speckle Noise (SN) is a downside to its usage since it decreases lesion conspicuity. Filters can be used to remove SN, but they involve time-consuming computation and parameter tuning. Several researchers have been developing complex Deep...

Glioblastoma (GB) is a malignant glioma associated with a mean overall survival of 12 to 18 months, even with optimal treatment, due to its high relapse rate and treatment resistance. The standardized first-line treatment consists of surgery, which allows for diagnosis and cytoreduction, followed by stereotactic fractionated radiotherapy and chemot...

Introduction One of the most common somatic responses of the human body to a mental health issue consists of alterations of the breathing rate. Typically, when an individual is under stress, tends to have a more rapid shallow breathing - instead of resorting to the diaphragm to help the air in and out the lungs, ends up conducting a thoracic breath...

Biosensing and microfluidics technologies are transforming diagnostic medicine by accurately detecting biomolecules in biological samples. Urine is a promising biological fluid for diagnostics due to its noninvasive collection and wide range of diagnostic biomarkers. Point-of-care urinalysis, which integrates biosensing and microfluidics, has the p...

Glioblastoma multiforme (GBM) remains a challenging disease, as it is the most common and deadly brain tumour in adults and has no curative solution and an overall short survival time. This incurability and short survival time means that, despite its rarity (average incidence of 3.2 per 100,000 persons), there has been an increased effort to try to...

Introduction The diagnosis of psychiatric disorders is mostly based on the clinical evaluation of the patient's signs and symptoms. Deep learning binary-based classification models have been developed to improve the diagnosis but have not yet reached clinical practice, in part due to the heterogeneity of such disorders. Here, we propose a normative...

Introduction Psychosis is usually preceded by a prodromal phase in which patients are clinically identified as being at in an “At Risk Mental State” (ARMS). A few studies have demonstrated the feasibility of predicting psychosis transition from an ARMS using structural magnetic resonance imaging (sMRI) data and machine learning (ML) methods. Howeve...

Head and neck cancer (HNC), also known as the cancer that can affect the structures between the dura mater and the pleura, is the 6th most common type of cancer. This heterogeneous group of malignancies is usually treated with a combination of surgery and radio- and chemotherapy, depending on if the disease is localized or at an advanced stage. How...

Introduction Due to the Covid-19 effects, mental health conditions are now, more than ever, affecting our daily lives - both personally and professionally. The average delay between the onset of first symptoms of a mental health disorder and seeking suitable healthcare is 11 years. The WHO states that the only sustainable way to reduce mental healt...

Introduction: Hyperglycemia in very preterm infants is associated with increased morbidity and mortality. We aimed to investigate potential associations between early hyperglycemia, neonatal cerebral magnetic resonance imaging (MRI), and neurodevelopment at 2.5 years. Methods: The study population included 69 infants with gestational age (GA) 22...

Background Early and accurate diagnosis of Alzheimer’s disease (AD) is essential for disease management and therapeutic choices that can delay disease progression. Machine learning (ML) approaches have been extensively used in attempts to develop algorithms for reliable early diagnosis of AD, although clinical usefulness, interpretability, and gene...

Aerogels are materials with unique properties, among which are low density and thermal conductivity. They are also known for their exquisite biocompatibility and biodegradability. All these features make them attractive for biomedical applications, such as their potential use in photothermal therapy (PTT). This technique is, yet, still associated w...

Multichannel transcranial direct current stimulation (tDCS) is a promising approach to target neuromodulation of neural networks by making use of variable number of electrodes and distances to facilitate/inhibit specific connectivity patterns. Optimization of the electric field (EF) spatial distribution through computational models can provide a mo...

Functional brain connectivity (FBC) has previously been examined in autism spectrum disorder (ASD) between-resting-state networks (RSNs) using a highly sensitive and reproducible hypothesis-free approach. However, results have been inconsistent and sex differences have only recently been taken into consideration using this approach. We estimated ma...

Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, t...

The properties of gold-based materials have been explored for centuries in several research fields, including medicine. Multiple published production methods for gold nanoparticles (AuNPs) have shown that the physicochemical and optical properties of AuNPs depend on the production method used. These different AuNP properties have allowed exploratio...

Deciding whether others’ emotions are genuine is essential for successful communication and social relationships. While previous fMRI studies suggested that differentiation between authentic and acted emotional expressions involves higher-order brain areas, the time course of authenticity discrimination is still unknown. To address this gap, we tes...

Background Alzheimer’s Disease (AD) is characterized by abnormal concentration of beta‐amyloid (AB) and tau proteins which can be assessed using positron emission tomography (PET). Currently, no relative standardized uptake value (rSUV) cutoff defines an AD diagnostic tau‐PET, and the literature is mainly focused on defining a cutoff per Braak stag...

Multi-parametric tissue characterisation is demonstrated using a 4-minute protocol based on diffusion trace acquisitions. Three diffusion regimes are covered simultaneously: pseudo-perfusion, Gaussian, and non-Gaussian diffusion. The clinical utility of this method for fast multi-parametric mapping for brain tumours is explored. A cohort of 17 brai...

Introduction The Eye Movement Desensitization and Reprocessing (EMDR) therapy has shown to be useful in the treatment of PTSD, general anxiety, stress and burnout. Nonetheless, assessing therapy progress has been limited to subjective appreciations of the patient and therapist, which compromise therapy efficacy, and the continuum of care (clinic an...

The global impact of cancer emphasizes the importance of developing innovative, effective and minimally invasive therapies. In the context of superficial cancers, the development of a multifunctional nanoparticle-based system and its in vitro and in vivo safety and efficacy characterization are, herein, proposed as a proof-of-concept. This multifun...

Background The presence of brain amyloid‐beta plaques is relevant for the diagnosis of Alzheimer’s Disease (AD) [1‐3]. However, positron emission tomography (PET), used to assess amyloid loading, is expensive and not widely available as other imaging modalities [2]. Therefore, the aim of this study was to assess if magnetic resonance imaging (MRI)...

Speech processing can be disturbed by primary brain tumors (PBT). Improvement of presurgical planning techniques decrease neurological morbidity associated to tumor resection during awake craniotomy. The aims of this work were: 1. To perform Diffusion Kurtosis Imaging based tractography (DKI-tract) in the detection of brain tracts involved in lang...

Background and Study Aims Cortical mapping (CM) with direct cortical stimulation (DCS) in awake craniotomy is used to preserve cognitive functions such as language. Nevertheless, patient collaboration during this procedure is influenced by previous neurological symptoms and growing discomfort with DCS duration. Our study aimed to evaluate the impac...

The microcirculation regulatory mechanisms are still poorly understood despite being central in the understanding of vascular physiology and pathophysiology. One practical way to study these mechanisms is through the acquisition of continuous blood flow signals with noninvasive techniques such as laser Doppler flowmetry (LDF). These signals can the...

Vessel topography is important in vascular medicine given the vascular abnormalities found in many developmental and cardiovascular diseases as well in ageing. Branching regions of any vascular tree are common sites for lesion due to the increased turbulent flow leading to dysmorphic features and dysfunction. Magnetic resonance imaging (MRI) is a p...

Microcirculation perfusion signals are oscillatory and complex in nature, reflecting the activity of highly dynamic regulation phenomena. Consequently, there is a constant need to obtain quantitative parameters to better translate properties such as fractality and complexity. These parameters are often difficult to interpret themselves, which precl...

The identification of biomarkers to discriminate Parkinson’s Disease from other motor diseases is crucial to provide suitable treatment to patients. This study proposes a novel approach for the classification of structural Magnetic Resonance Imaging (MRI), Dopamine Transporter scan data (DaTscan) and demographic information (age and gender) to diff...

Massage is commonly used as a complementary therapy for many different conditions. Demonstration of its physiological impact and understanding of its therapeutic mechanisms is still insufficient and often inconclusive. This study aims to characterize the physiological effects of effleurage, one of the most popular techniques, on human in vivo micro...

The quantitative assessment of cardiovascular functions is particularly complicated, especially during any physiological challenge (e.g., exercise), with physiological signals showing intricate oscillatory properties. Signal complexity is one of such properties, and reflects the adaptability of the physiological systems that generated them. However...

The diagnosis of Parkinsonian Syndromes (PS) at early-stages is a challenge. PS usually present similar symptoms, and the diagnosis is mainly clinical, causing often misdiagnosis between PS and other movement disorders. Parkinson’s Disease (PD) is the most common PS, affecting a large part of the worldwide population. Medical imaging such as Magnet...

Abstract. All those that work in markets research know, for long, that there is a distance between the intentions that consumers manifest overtly (e.g. in surveys or focus groups) and what they practise. One cause is that these methods assume the consumer as a full rational decision-maker, although most consumption acts arise in the non-conscious p...

Background: Brain volumes have been used as research biomarkers both in health and in Alzheimer's disease(AD). In order to improve the comparability between studies and aid future analytical software platform choice in the research setting, here we compare two segmentation pipelines of structural brain magnetic resonance imaging(sMRI): the SPM12 t...

Laser Doppler flowmetry (LDF) and reflection photoplethysmography (PPG) are standard technologies to access microcirculatory function in vivo. However, different light frequencies mean different interaction with tissues, such that LDF and PPG flowmotion curves might have distinct meanings, particularly during adaptative (homeostatic) processes. The...

The wavelet transform analysis (WT) of optical phenomena gathered from techniques such as laser Doppler flowmetry (LDF) is well known, and regarded as a useful mechanistic assessment refinement. In the present study we applied this strategy to one other technology, photoplethysmography (PPG) and compare it with equivalent signals obtained under the...

Recent studies identified a contralateral response observed in the veno arterial reflex in the test limb, both in animals and humans. This adaptative reflex is known for a long time but its mechanistic explanation is still unclear. In the present study we assessed this reflex as a function of age. 8 healthy volunteers (mean 50.13 ± 6.17 yo) from bo...

Effleurage is surely one of the most popular massage techniques used for multiple purposes. Its physiological impact and mechanisms are still poorly understood, sometimes inconclusive. We aim to characterize the cardiovascular impact of this technique on human in vivo microcirculation. To this end, distal blood perfusion was non invasively quantifi...

Microcirculation is often assessed by noninvasive technologies such as laser Doppler flowmetry (LDF), laser Doppler perfusionimaging (LDPI), photoplethysmography (PPG) and, more recently, polarized light spectroscopy (PLS). LDF and PPG measure perfusion in a small tissue region on a continuous mode, producing complex and multiscaled oscillatory sig...

The study of vessel topography is of great importance in vascular medicine since vascular abnormalities or dysmorphic features are present in many developmental and cardiovascular disorders, as well as in ageing, even when no clinical manifestations are present. Branching regions of any vascular tree is a common site for architectural dysmorphia an...

One of the greatest challenges in the study of emotions and emotional states is their measurement. The techniques used to measure emotions depend essentially on the authors’ definition of the concept of emotion. Currently, two types of measures are used: subjective and objective. While subjective measures focus on assessing the conscious recognitio...

Diffusion kurtosis imaging (DKI) is a diffusion-weighted MRI technique that probes the non-Gaussian diffusion of water molecules within biological tissues. The purpose of this study was to investigate the DKI model optimal b-values combinations in invasive ductal carcinoma (IDC) versus ductal carcinoma in situ (DCIS) breast lesions. The study inclu...

INTRODUCTION A Evidences of a so called limb collaboration between both lower limbs has been observed in human, during a venoarterial reflex protocol 1 where significant perfusion reductions were note in both test and control foot in young healthy individuals The same phenomena was depicted by the hyperoxia mouse model, following a hindlimb ischemi...

INTRODUCTION Recently, a lower limb collaboration was observed with a venoarterial reflex protocol 1 , where significant perfusion reductions were note both in the test as in the control foot of young healthy individuals. The same group demonstrated, by the hyperoxia mouse model, a similar effect following a hindlimb ischemia procedure 2. In the pr...

Modelling is essential for a better understanding of microcirculatory pathophysiology. In this study we tested our hyperoxia-mouse model with healthy and non-healthy mice. Animals (n = 41) were divided in groups—a control group, with 8 C57/BL6 non-transgenic male mice, a diabetic group (DB), with 8 C57BLKsJ-db/db obese diabetic mice and the corresp...

The microcirculatory physiology critically depends on a highly structured network of vessels arranged to deliver oxygen to the tissues in a optimized way. In turn, oxygen is also a critical regulatory element of these functions, not only acting locally, influencing resistance, but also controlled by other local and systemic (homeostatic) regulators...

The use of animal models still presents many difficulties mostly because (a) no single model accurately recreates one disease, (b) the use of so many models impair comparison of results and (c) extrapolation to human is very limited. We have been dedicated to develop the potential use of oxygen as a challenger to study microcirculatory function and...

P11 - Studying the Venoarteriolar reflex as part of the in vivo regulation mechanism of pheripheral circulation