Two-dimensional low resolution raman spectroscopy applied to fast discrimination of clinically relevant microorganisms: a whole-organism fingerprinting approach

The discrimination of the bacteria that cause gastroenteritis through classical microbiological methods is very efficient in the great majority of the cases. However, the high cost of chemicals and the time spent for such identifications, about four days, could generate serious consequences for the patients. Thus, the search for low cost spectroscopic methods which would allow a fast and reagentless discrimination of these microorganisms is extremely relevant. In this work the main microorganisms that cause gastroenteritis: E. coli, S. chroleraesuis, S. flexneri were studied. For each of the microorganisms sixty different dispersions were prepared using physiological solution as solvent and its Raman spectra recorded. The 1D spectra obtained were similar, making it very difficult to differentiate the microorganisms. However, applying the 2D correlation method, it was possible to identify the microorganisms evaluated using the synchronous spectrum as whole-organism fingerprinting in a reduced time interval (~10 h).A diferenciação de bactérias causadoras de gastrenterites através de métodos microbiológicos clássicos é muito eficiente, na maior parte dos casos. Todavia, o elevado custo dos reagentes e o tempo necessário para tais determinações, cerca de 4 dias, podem causar sérias conseqüências, quando os pacientes são crianças, idosos ou adultos com baixa resistência imunológica. Assim, a pesquisa por métodos espectroscópicos de baixo custo, que permitam tais determinações com pouco uso de reagentes e em curtos intervalos de tempo é extremamente relevante. Neste trabalho os principais microrganismos causadores de gastrenterites, E. coli, S. chroleraesuis, S. flexneri foram avaliados. Foram preparadas sessenta dispersões para cada um dos microrganismos, usando solução fisiológica como solvente, e seus espectros adquiridos. Os espectros obtidos foram muito similares, tornando muito difícil a diferenciação dos microrganismos. Entretanto, aplicando a teoria de correlação generalizada em 2D, foi possível diferenciar os microrganismos avaliados usando o espectro síncrono como impressão digital do organismo em um curto intervalo de tempo (~10h).7378Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Detection of low-magnetic fields by rubidium (87Rb) vapor cell

Journal of Physics: Conference Series, Volume 1837, 30th Micromechanics and Microsystems Europe Workshop (MME) 2019 18-20 August 2019, Wolfson College, Oxford, United KingdomThis paper describes the work carried out to assess the use of a quartz reference rubidium (87Rb) vapor cell for non-invasively magnetoencephalography, avoiding cryogenically cooled sensors as the Superconducting Quantum Interference Devices (SQUIDs). An experimental setup based on a cylindrical glass vapor cell of 87Rb (l = 75 mm, d =19 mm) was developed. The 87Rb cell was heated to around 75°C and it was optically pumped with polarized light (range 750-850 nm), tuned to the D1 transition of rubidium, for spin-polarization of the atoms, and the intensity of the light transmitted through the cell was detected using a photodiode. Without magnetic field, the photodiode current is maximized but when a small transverse magnetic field is present a measurable drop in light transmission occurs. A Magnetic Shielded Box (MSB) made by a nickel-iron ferromagnetic alloy, was used for nulling background magnetic fields and the transmittance light versus transverse magnetic field intensity (100-1000 nT) was measured.This work is supported by: Project MME reference 105399, FCT Strategic Project UID/EEA/04436/2019, Infrastructures Micro&NanoFabs@PT, reference NORTE-01-0145-FEDER-022090, POR Norte, Portugal 2020, SARSPEC Lda, V.N. Gaia-Portugal

Visual and ocular motor function in the atypical form of neurodegeneration with brain iron accumulation type I

BACKGROUND/AIMS: Neurodegeneration with brain iron accumulation (NBIA) type I is a rare disease that can be divided into a classical or atypical variant, according to age of onset and clinical pattern. Neuro-ophthalmological involvement has been documented in the classical variant but only anecdotically in the atypical variant. We sought to describe the visual and ocular motor function in patients with atypical form of NBIA type I. METHODS: Cross-sectional study, including patients with genetically confirmed NBIA type I and classified as atypical variant, who underwent ophthalmological examination with best corrected visual acuity (BCVA), optical coherence tomography (OCT), fundus autofluorescence (FAF), electroretinography (ERG), visual evoked potentials (VEP) and video-oculography. RESULTS: Seven patients with a mean BCVA of 0.12±0.14 logMAR were included. Only two patients showed structural evidence of advanced retinopathy in OCT and FAF, and there were no cases of optic atrophy. ERG data, however, showed abnormal scotopic and/or photopic responses in all patients. VEP were normal in all three patients. Ocular fixation was markedly unstable (eg, increased rate of saccadic pulses) in the majority of patients (5). Additional mild ocular motor disturbances included low gain pursuit (2), hypermetric saccades (1), low gain optokinetic (2) and caloric and rotatory responses (3). CONCLUSION: Functional retinal changes associated with marked instability of ocular fixation should be included in the clinical spectrum of NBIA, particularly in the atypical form.info:eu-repo/semantics/publishedVersio

MAC protocol for low-power real-time wireless sensing and actuation

This paper presents LPRT, a new medium access control (MAC) protocol for wireless sensing and actuation systems. Some of the characteristics of the proposed protocol are low power consumption, support for real-time and loss intolerant traffic through contention-free operation and a retransmission scheme, flexibility, and high throughput efficiency. The LPRT protocol was implemented it in the MICAz motes, a platform for the development of wireless sensor networks. We also briefly describe a wireless hydrotherapy application that benefits from the use of the proposed protocol. This paper also provides experimental results and comparison of the proposed protocol with the CSMA/CA protocol of IEEE 802.15.4.Agência de Inovação (ADI)Fundação para a Ciência e a Tecnologia (FCT

SU-8 based waveguide for optrodes

Neural probes can be equipped with light for optogenetics applications. Different approaches are used for delivering light to the tissue: an optical fiber coupled to the probe, a µLED or a waveguide integrated on the probe. Small probe dimensions, adequate optical power for photostimulation and good tissue penetration for in-vivo experiments are critical requirements. Thus, integrating a waveguide is a promising solution. This work shows the design and simulation of a SU-8 based waveguide for integration in a neural probe. The waveguide contains 3 apertures, spaced by 0.5 mm, which will allow the photostimulation of different brain regions simultaneously.ANI supports this work through the Brain-Lighting project by FEDER funds through Portugal 2020, COMPETE 2020 with the reference POCI-01-0247-FEDER-003416. S. B. Goncalves is supported by the Portuguese Foundation for Science and Technology, grant PD/BD/105931/2014, MIT-Portugal program.info:eu-repo/semantics/publishedVersio

Differentiation between normal and tumor mammary glands with depth-resolved attenuation coefficient from optical coherence tomography

Optical coherence tomography (OCT) is a well-established imaging technology for high-resolution, cross-sectional imaging of biological tissues. Imaging processing and light attenuation coefficient estimation allows to further improve the OCT diagnostic capability. In this paper we use a commercial OCT system, Telesto II-1325LR from Thorlabs, and demonstrate its ability to differentiate normal and tumor mammary mouse glands with the OCT attenuation coefficient. Using several OCT images of normal and tumor mammary mouse glands (n = 26), a statistical analysis was performed. The attenuation coefficient was calculated in depth, considering a slope of 0.5 mm. The normal glands present a median attenuation coefficient of 0.403 mm-1, comparatively to 0.561 mm-1obtained for tumor mammary glands. This translates in an attenuation coefficient approximately 39% higher for tumor mammary glands when compared to normal mammary glands. The OCT attenuation coefficient estimation eliminates the subjective analysis provided by direct visualization of the OCT images.This work is supported by:-OCT-RAMAN, PTDC/FISOTI/28296/2017 with the operation code NORTE-01- 0145-FEDER-028296;—MPhotonBiopsy, PTDC/FISOTI/1259/2020;—CMEMS-UMinho Strategic Project UIDB/04436/2020;- Infrastructures Micro&NanoFabs@PT, operation code NORTE 01-0145-FEDER022090, POR Norte, Portugal

Collateral pial circulation relates to the degree of brain edema on CT 24 hours after ischemic stroke

Background Cerebral edema is frequent in patients with acute ischemic stroke (AIS) who undergo reperfusion therapy and is associated with high mortality. The impact of collateral pial circulation (CPC) status on the development of edema has not yet been determined. Methods We studied consecutive patients with AIS and documented M1-middle cerebral artery (MCA) and/or distal internal carotid artery (ICA) occlusion who underwent reperfusion treatment. Edema was graded on the 24-hour non-contrast computed tomography (NCCT) scan. CPC was evaluated at the acute phase (≤6 hours) by transcranial color-coded Doppler, angiography and/or CT angiography. We performed an ordinal regression model for the effect of CPC on cerebral edema, adjusting for age, baseline National Institutes of Health Stroke Scale, Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on admission, NCCT, parenchymal hemorrhagic transformation at 24 hours and complete recanalization at six hours. Results Among the 108 patients included, 49.1% were male and mean age was 74.2 ± 11.6 years. Multivariable analysis showed a significant association between cerebral edema and CPC status (OR 0.22, 95% CI 0.08-0.59, p = 0.003), initial ASPECTS (OR 0.72, 95% CI 0.57-0.92, p = 0.007) and parenchymal hemorrhagic transformation (OR 23.67, 95% CI 4.56-122.8, p < 0.001). Conclusions Poor CPC is independently associated with greater cerebral edema 24 hours after AIS in patients who undergo reperfusion treatment.info:eu-repo/semantics/publishedVersio

Non-contact optical analysis of the viscoelastic properties for food quality using Brillouin spectroscopy

Brillouin spectroscopy probes the viscoelastic properties of materials by observing the scattered light spectrum from a laser source incident on a given sample. The peak contained in the Brillouin scattering region of the spectrum can be directly correlated to the storage and loss modulus, providing a complex analysis of the physical properties of the study subject (Figure1a) [1]. For the food industry, where the traditional and contact-based rheological measurement techniques dominate the characterization of the physical characteristics of products from raw material to finished foods, Brillouin spectroscopy brings a new and relevant noncontact alternative [2]. Also, this technique is useful for measurement of products inside of sealed packages, allowing the characterization of samples through a transparent window without any violation of the package. In this study, we explored the potential of the Brillouin spectroscopy to infer changes in viscoelastic properties that occur in different food products when submitted to heating and cooling cycles, freezing and unfreezing cycles, and normal time-based decay [3]. The data was acquired using the setup described in Figure 1b. Significant changes were already observed in the viscoelastic properties of cow’s milk after every day of room temperature and fridge storage, and in cooking oil after consecutive cooling and heating cycles (170 ºC). We also obtained spectrums for meat and fish after every day of fridge storage and after freezing and unfreezing cycles. For non-uniform samples, the acquisition location affects the peak obtained, so different approaches to the acquisition method are still being investigated. These results hint at a future in which we can check if a product was handled with care and transported under the right conditions, if the frozen products have only been frozen once or if meat and fish are really fresh and safe to consume, without ever opening a package or touching/handling the product. This will increase consumer safety and confidence and provide the industry with the necessary tools to ensure and improve the quality of their products without waste.This work was supported by FCT with the project MPhotonBiopsy, PTDC/FIS-OTI/1259/2020. B. Esteves thanks to FCT for the Ph.D. grant with the reference 2021.07239.BD

Double-layer flexible neural probe with closely spaced electrodes for high-density in vivo brain recordings

Flexible polymer neural probes are an attractive emerging approach for invasive brain recordings, given that they can minimize the risks of brain damage or glial scaring. However, densely packed electrode sites, which can facilitate neuronal data analysis, are not widely available in flexible probes. Here, we present a new flexible polyimide neural probe, based on standard and low-cost lithography processes, which has 32 closely spaced 10 μm diameter gold electrode sites at two different depths from the probe surface arranged in a matrix, with inter-site distances of only 5 μm. The double-layer design and fabrication approach implemented also provides additional stiffening just sufficient to prevent probe buckling during brain insertion. This approach avoids typical laborious augmentation strategies used to increase flexible probes' mechanical rigidity while allowing a small brain insertion footprint. Chemical composition analysis and metrology of structural, mechanical, and electrical properties demonstrated the viability of this fabrication approach. Finally, in vivo functional assessment tests in the mouse cortex were performed as well as histological assessment of the insertion footprint, validating the biological applicability of this flexible neural probe for acquiring high quality neuronal recordings with high signal to noise ratio (SNR) and reduced acute trauma.This work was supported by FCT with: project OpticalBrain reference PTDC/CTM-REF/28406/2017, operation code POCI-01-0145-FEDER-028406, through the COMPETE 2020; CMEMS-UMinho Strategic Project UIDB/04436/2020; and Infrastructures Micro&NanoFabs@PT, operation code NORTE 01-0145-FEDER-022090, POR Norte, Portugal 2020. This work has also been funded by: ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI – Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122); national funds, through the Foundation for Science and Technology (FCT) – project UIDB/50026/2020 and UIDP/50026/2020; the projects NORTE-01-0145-FEDER-000013 and NORTE01-0145-FEDER-000023, supported by Norte Portugal Regional Operational Program (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); FCT project PTDC/MED-NEU/28073/2017 (POCI-01-0145-FEDER028073); and by The Branco Weiss fellowship – Society in Science (ETH Zurich)

Keratocystic odontogenic tumor overexpresses invadopodia-related proteins, suggesting invadopodia formation

OBJECTIVE: Keratocystic odontogenic tumor (KOT) is an odontogenic neoplasm that shows aggressive clinical behavior and local invasiveness. Invadopodia are actin-rich cellular protrusions exhibiting proteolytic pericellular activity, thereby inducing focal invasion in neoplastic cells and increasing neoplasms aggressiveness. Thus, this study aimed to evaluate immunoexpression of invadopodia-related proteins, cortactin, MT1-MMP, Tks4, and Tks5, in KOT. STUDY DESIGN: Immunohistochemistry of 16 cases of KOT, eight cases of calcifying cystic odontogenic tumor (CCOT), and eight samples of the oral mucosa (OM) was carried out to assess the expression of the above described invadopodia-related proteins in the basal and suprabasal layer. RESULTS: KOT samples showed higher and significant immunoexpression of cortactin, MT1-MMP, TKs4, and TKs5 compared with the CCOT and OM samples. Significant expression of all these proteins was observed in the basal layer compared with the suprabasal layer in KOT. CONCLUSIONS: Overexpression of cortactin, MT1-MMP, TKs4, and TKs5 was observed in KOT compared with samples of CCOT and OM. These proteins were also overexpressed in the basal over the suprabasal layer of KOT samples. Taken together, these results suggest the participation of invadopodia-related proteins on the pathogenesis of this lesion