Label-Free Electrical Biosensor Arrays: A New Challenge for TFT Technology

Pedro Estrela,Peng Li,Simon D. Keighley,Piero Migliorato 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.1

Biotechnology is in great need of low-cost intelligent biochips capable of massive parallel detection to be used in portable instrumentation. One way this may be achieved is to exploit mature semiconductor technologies for the development of biosensor arrays. We review here two highly promising techniques for label-free electrical detection of biomolecular interactions: potentiometric and electrochemical impedance spectroscopy. Thin film transistor technology can play an important role in the development of these techniques in biosensor microarrays.

Sensory neurons and osteoblasts: close partners in a microfluidic platform

Neto, Estrela,Alves, Cecí,lia J.,Sousa, Daniela M.,Alencastre, Inê,s S.,Lourenç,o, Ana H.,Leitã,o, Luí,s,Ryu, Hyun R.,Jeon, Noo L.,Fernandes, Rui,Aguiar, Paulo,Almeida, Ra Oxford University Press 2014 Integrative biology Vol.6 No.6

<P>Innervation has proven to be critical in bone homeostasis/regeneration due to the effect of soluble factors, produced by nerve fibers, associated with changes in the activity of bone cells. Thus, in this study, we have established and characterized a coculture system comprising sensory neurons and osteoblasts to mimic the <I>in vivo</I> scenario where nerve fibers can be found in a bone microenvironment. Embryonic or adult primary dorsal root ganglion (DRG) and MC3T3-E1 osteoblastic cells were cocultured in compartmentalized microfluidic platforms and morphological and functional tests were performed. The time of adhesion and readout of axonal outgrowth were improved by the alignment of DRG with the axis of microgrooves, which showed to be a crucial step for the designed experiments. Cocultures of entire DRG from adult origin with osteoblasts were performed, showing extended DRG projections towards the axonal compartment, reaching osteoblastic cells. Immunocytochemistry showed that the neurites present within the osteoblastic compartment were immunoreactive to synapsin and calcitonin gene-related peptide suggesting the presence of specialized structures involved in this crosstalk. This evidence was further confirmed by electron microscopy where varicosities were detected as well as electron dense structures in neurite membranes. Aiming to mimic the properties of tissue extracellular matrices, MC3T3-E1 cells were seeded in the axonal side upon laminin, collagen or within 3D functionalized alginate matrices and axonal outgrowth was clearly observed. In order to analyze and quantify data with reproducible image analysis, a semi-automated algorithm was also developed. The collagen and laminin substrates displayed a higher amount of axons reaching the axonal side. Overall, the established method revealed to be a suitable tool to study the interaction between the peripheral nervous system and bone cells in different contexts mimicking the <I>in vivo</I> scenario.</P>

Biologically Sensitive Field-Effect Devices using Polysilicon TFTs

Piero Migliorato,Pedro Estrela,Andrew G. Stewart,Simon D. Keighley 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.I

This paper presents a review of recent developments in the detection of biomolecular interactions with field-effect devices. Ion-sensitive field-effect transistors (ISFETs) and enzyme field-effect transistors (EnFETs), based on polycrystalline silicon (poly-Si) TFTs, are discussed. Label-free electrical detection of DNA hybridization has been achieved by a new method, by using MOS capacitors or poly-Si TFTs. The method can in principle be extended to other chemical or biochemical systems, such as proteins and cells.o

Reference values for pulp oxygen saturation as a diagnostic tool in endodontics: a systematic review and meta-analysis

Lambert Paula,Miguens Sergio Augusto Quevedo,Solda Caroline,Sganzerla Juliana Tomaz,Reichert Leandro Azambuja,Estrela Carlos,Barletta Fernando Branco 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.4

Objectives: This systematic review aimed to identify mean oxygen saturation values (SpO2) using pulse oximetry in permanent maxillary anterior teeth. Materials and Methods: The MEDLINE, Scientific Electronic Library Online, Cochrane Central Register of Controlled Trials, EMBASE, and Literatura Latino Americana em Ciências da Saúde electronic databases were searched. Combinations and variations of “oximetry” AND “dental pulp test” were used as search terms. Studies reporting means and standard deviations of SpO2 values were included. Two reviewers independently extracted data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Heterogeneity was assessed using the I2 statistic, and all analyses were performed using R software. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool and the Newcastle-Ottawa scale. Results: Of the 251 studies identified, 19 met the eligibility criteria and were included (total sample, 4,541 teeth). In the meta-analysis, the mean SpO2 values were 84.94% (95% confidence interval [CI], 84.85%–85.04%) for the central incisors, 89.29% (95% CI, 89.22%–89.35%) for the lateral incisors, and 89.20% (95% CI, 89.05%–89.34%) for the canines. The studies were predominantly low-quality due to the high risk of bias associated with the index test, unclear risk regarding patient selection, and concerns about outcome assessment. Conclusions: Although most studies were low-quality, the oxygen saturation levels in normal pulp could be established (minimum saturation, 77.52%). Despite the risk of bias of the included studies, the reference values reported herein are clinically relevant for assessments of changes in pulp status.

Influence of voxel size on cone-beam computed tomography-based detection of vertical root fractures in the presence of intracanal metallic posts

Yamamoto-Silva, Fernanda Paula,de Oliveira Siqueira, Claudeir Felipe,Silva, Maria Alves Garcia Santos,Fonseca, Rodrigo Borges,Santos, Ananda Amaral,Estrela, Carlos,de Freitas Silva, Brunno Santos Korean Academy of Oral and Maxillofacial Radiology 2018 Imaging Science in Dentistry Vol.48 No.3

Purpose: This study was performed to evaluate the influence of voxel size and the accuracy of 2 cone-beam computed tomography (CBCT) systems in the detection of vertical root fracture (VRF) in the presence of intracanal metallic posts. Materials and Methods: Thirty uniradicular extracted human teeth were selected and randomly divided into 2 groups(VRF group, n=15; and control group, n=15). The VRFs were induced by an Instron machine, and metallic posts were placed in both groups. The scans were acquired by CBCT with 4 different voxel sizes: 0.1 mm and 0.16 mm (for the Eagle 3D V-Beam system) and 0.125 mm and 0.2 mm (for the i-CAT system) (protocols 1, 2, 3, and 4, respectively). Interobserver and intraobserver agreement was assessed using the Cohen kappa test. Sensitivity and specificity were evaluated and receiver operating characteristic analysis was performed. Results: The intraobserver coefficients indicated good (0.71) to very good (0.83) agreement, and the interobserver coefficients indicated moderate (0.57) to very good (0.80) agreement. In respect to the relationship between sensitivity and specificity, a statistically significant difference was found between protocols 1 (positive predictive value: 0.710, negative predictive value: 0.724) and 3 (positive predictive value: 0.727, negative predictive value: 0.632) (P<.05). The least interference due to artifact formation was observed using protocol 2. Conclusion: Protocols with a smaller voxel size and field of view seemed to favor the detection of VRF in teeth with intracanal metallic posts.

Influence of voxel size on cone-beam computed tomography-based detection of vertical root fractures in the presence of intracanal metallic posts

Fernanda Paula Yamamoto-Silva,Claudeir Felipe de Oliveira Siqueira,Maria Alves Garcia Santos Silva,Rodrigo Borges Fonseca,Ananda Amaral Santos,Carlos Estrela,Brunno Santos de Freitas Silva 대한영상치의학회 2018 Imaging Science in Dentistry Vol.48 No.3

Purpose: This study was performed to evaluate the influence of voxel size and the accuracy of 2 cone-beam computed tomography (CBCT) systems in the detection of vertical root fracture (VRF) in the presence of intracanal metallic posts. Materials and Methods: Thirty uniradicular extracted human teeth were selected and randomly divided into 2 groups (VRF group, n=15; and control group, n=15). The VRFs were induced by an Instron machine, and metallic posts were placed in both groups. The scans were acquired by CBCT with 4 different voxel sizes: 0.1 mm and 0.16 mm (for the Eagle 3D V-Beam system) and 0.125 mm and 0.2 mm (for the i-CAT system) (protocols 1, 2, 3, and 4, respectively). Interobserver and intraobserver agreement was assessed using the Cohen kappa test. Sensitivity and specificity were evaluated and receiver operating characteristic analysis was performed. Results: The intraobserver coefficients indicated good (0.71) to very good (0.83) agreement, and the interobserver coefficients indicated moderate (0.57) to very good (0.80) agreement. In respect to the relationship between sensitivity and specificity, a statistically significant difference was found between protocols 1 (positive predictive value: 0.710, negative predictive value: 0.724) and 3 (positive predictive value: 0.727, negative predictive value: 0.632) (P<.05). The least interference due to artifact formation was observed using protocol 2. Conclusion: Protocols with a smaller voxel size and field of view seemed to favor the detection of VRF in teeth with intracanal metallic posts.

Ethereal Extract of Pepper: Preventing Atherosclerosis and Left Ventricle Remodeling in LDL Receptor Knockout Mice

Leandro dos Santos,Leticia de Oliveira Maciel,Erika Kristina Incerpi Gracia,Evelise Aline Soares,Danielle Aparecida Quintino Si,Valerio Garrone Barauna,Heder Frank Gianotto Estrela,Carollayne Mendonca 한국식품영양과학회 2021 Preventive Nutrition and Food Science Vol.26 No.1

Cardiovascular diseases are the leading cause of mortality and morbidity worldwide. In this study we compared the effects of oral treatment with red pepper ethereal extracts or simvastatin on dyslipidemia, left ventricle remodeling, and atherosclerotic lesions of low-density lipoprotein (LDL) receptor knockout mice (LDLr<SUP>−/−</SUP>) fed a hyperlipidic diet. Forty 3-month-old male mice were distributed into four groups: control (C; animals fed a standard diet), HL (animals fed a hyperlipidic diet), and HL+P or HL+S (animals fed a hyperlipidic diet plus red pepper ethereal extracts or simvastatin, respectively). After 60 days, treatment with both red pepper ethereal extracts and simvastatin prevented dyslipidemia, atherosclerotic lesion progression, and left ventricle hypertrophy. Our results suggest a cardioprotective effect of red pepper ethereal extracts in LDLr<SUP>−/−</SUP> mice, which is comparable to the well-known effects of simvastatin.

Comparative analysis of bond strength to root dentin and compression of bioceramic cements used in regenerative endodontic procedures

Rodrigues Maykely Naara Morais,Bruno Kely Firmino,Alencar Ana Helena Gonçalves de,Silva Julyana Dumas Santos,Siqueira Patrícia Correia de,Decurcio Daniel de Almeida,Estrela Carlos 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.4

Objectives This study compared the Biodentine, MTA Repair HP, and Bio-C Repair bioceramics in terms of bond strength to dentin, failure mode, and compression. Materials and Methods Fifty-four slices obtained from the cervical third of 18 single-rooted human mandibular premolars were randomly distributed (n = 18). After insertion of the bioceramic materials, the push-out test was performed. The failure mode was analyzed using stereomicroscopy. Another set of cylindrically-shaped bioceramic samples (n = 10) was prepared for compressive strength testing. The normality of data distribution was analyzed using the Shapiro-Wilk test. The Kruskal-Wallis and Friedman tests were used for the push-out test data, while compressive strength was analyzed with analysis of variance and the Tukey test, considering a significance level of 0.05. Results Biodentine presented a higher median bond strength value (14.79 MPa) than MTA Repair HP (8.84 MPa) and Bio-C Repair (3.48 MPa), with a significant difference only between Biodentine and Bio-C Repair. In the Biodentine group, the most frequent failure mode was mixed (61%), while in the MTA Repair HP and Bio-C Repair groups, it was adhesive (94% and 72%, respectively). Biodentine showed greater resistance to compression (29.59 ± 8.47 MPa) than MTA Repair HP (18.68 ± 7.40 MPa) and Bio-C Repair (19.96 ± 3.96 MPa) (p < 0.05). Conclusions Biodentine showed greater compressive strength than MTA Repair HP and Bio-C Repair, and greater bond strength than Bio-C Repair. The most frequent failure mode of Biodentine was mixed, while that of MTA Repair HP and Bio-C Repair was adhesive. Objectives This study compared the Biodentine, MTA Repair HP, and Bio-C Repair bioceramics in terms of bond strength to dentin, failure mode, and compression. Materials and Methods Fifty-four slices obtained from the cervical third of 18 single-rooted human mandibular premolars were randomly distributed (n = 18). After insertion of the bioceramic materials, the push-out test was performed. The failure mode was analyzed using stereomicroscopy. Another set of cylindrically-shaped bioceramic samples (n = 10) was prepared for compressive strength testing. The normality of data distribution was analyzed using the Shapiro-Wilk test. The Kruskal-Wallis and Friedman tests were used for the push-out test data, while compressive strength was analyzed with analysis of variance and the Tukey test, considering a significance level of 0.05. Results Biodentine presented a higher median bond strength value (14.79 MPa) than MTA Repair HP (8.84 MPa) and Bio-C Repair (3.48 MPa), with a significant difference only between Biodentine and Bio-C Repair. In the Biodentine group, the most frequent failure mode was mixed (61%), while in the MTA Repair HP and Bio-C Repair groups, it was adhesive (94% and 72%, respectively). Biodentine showed greater resistance to compression (29.59 ± 8.47 MPa) than MTA Repair HP (18.68 ± 7.40 MPa) and Bio-C Repair (19.96 ± 3.96 MPa) (p < 0.05). Conclusions Biodentine showed greater compressive strength than MTA Repair HP and Bio-C Repair, and greater bond strength than Bio-C Repair. The most frequent failure mode of Biodentine was mixed, while that of MTA Repair HP and Bio-C Repair was adhesive.