Ricardo Tadeu Lopes

• D.Sc.
• Professor (Full) at Federal University of Rio de Janeiro

Objective The study aimed to assess the effectiveness of micro-CT in assessing the removal of obturation material from canals filled with gutta-percha and bioceramic sealer. Materials and methods Forty mandibular premolars were prepared with the Reciproc Blue R25 system and obturated with the single cone technique and Bio C Sealer. The specimens w...

This study examines the brain morphology of Pliocene specimens of the South American Echimyidae rodent Eumysops chapalmalensis through virtual endocasts and comparisons with extant members of the family. Shape variation is analysed through geometric morphometrics, and the relative sizes of the brain and its components are estimated using phylogenet...

The integrity of flexible risers, essential for transporting oil from wells to platforms, is often compromised by residual gases such as CO2 and H2S, which cause fatigue through corrosion. The marine environment, with its bending loads, radial forces, and internal and external pressures, intensifies this process, requiring continuous monitoring and...

This study examines the metabolic rates of notosuchian crocodyliforms. Although predominantly composed of terrestrial forms, the group also encompasses the puta-tively semi-aquatic itasuchids. The notosuchian record is particularly rich in Brazil and Argentina, which provides a basis for understanding their ecology and physiology. This research exp...

We review the taxonomy of Atractus species distributed continuously along northeastern portions of the Andes of Colombia (= Eastern Cordillera), Sierra of Perijá on the Colombia–Venezuela border, and Cordillera of Mérida in northwestern Venezuela. We assess the taxonomic status of 29 species names on the basis of congruence between quantitative and...

The oil and natural gas industry is one of the largest producers of Naturally Occurring Radioactive Material (NORM) worldwide. The scale and sludge are NORM wastes with the highest activity concentration levels, reaching 3500 Bq per g of 226Ra (scale). As wastes (sludge, scale, and produced water) are constantly produced in routine activities, a sp...

High resolution X-ray computed microtomography (microCT) is a non-destructive method for assessing soil structure as influenced by land use and management. A microCT soil scan produces data and information, in microscale, on the shape, size, distribution, volume, area and pore connectivity of the soil, and allows a 3D visualization of the soil samp...

Aim: To determine new energy parameters in micro-CT to allow appropriate segmentation of dental cementum from the surrounding structures. Methods: For this pilot study, 11 single-rooted premolar teeth of young subjects aged 12 to 21 were selected. The teeth were scanned using high-energy microtomography (SkyScan 1173, Bruker) with varying acquisiti...

The historical and cultural significance of artistic works and archaeological artifacts underscores the imperative use of non-destructive testing methods in cultural heritage objects. Analyzing pigments in artwork poses a specific analytical challenge that demands a combination of various techniques to accurately determine chemical compositions. In...

This work investigates the impact of voids in three-phase cables. Voids in cross-linked polyethylene (XLPE) insulated cables are identified as weak points, causing operational changes due to partial discharges. Changes in electric field strengths and current density were evaluated in cable models with Copper (Cu) and Aluminum (Al) cores, containing...

Air voids within cables insulated with cross-linked polyethylene (EPR) have been identified as vulnerabilities due to their association with operational charges resulting from partial discharges. These voids generate intense and non-uniform electric fields, leading to an increase in dissipated power. Therefore, this work investigates the impact of...

Introduction This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Materials and Methods Forty mandibular premolars with oval canals were divided into four group...

Aim: Evidence suggests that translocation of oral pathogens through the oral-gut axis may induce intestinal dysbiosis. This study aimed to evaluate the impact of a highly leukotoxic Aggregatibacter actinomycetemcomitans (Aa) strain on the gut microbiota, intestinal mucosal integrity and immune system in healthy mice. Methods: Eight-week-old male...

This study assessed canal preparation effects on disinfection and dentin preservation. Thirty mandibular incisors were paired into two experimental groups ( n = 10). Following contamination, the initial microbial sample was collected. Instruments 30/0.03 (Group 1) and 30/0.05 (Group 2) were employed and a second sample was obtained. Canals were enl...

https://www.routledge.com/Intelligent-Healthcare-Systems/Estrela/p/book/9781032052724 Medical cyber-physical systems, image processing, microscopy, security, biomedical imaging, multi-modal sensing, automation, robotics, network layers, software design, and biometrics for high computational load (CL) are shown. The book addresses the dimensionalit...

The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy. Aim The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT. Material and Method Forty human mandibular...

The aim was to evaluate primary implant stability and bone microarchitecture in two drilling situations, by comparing the conventional technique (CT) and osseodensification (OD) (Versah Burs - Jackson - Mississippi - USA). The implant insertion torque (IT), implant stability quotient (ISQ), and the peri-implant trabecular microstructure were assess...

This research aimed to enhance the impregnation of carboxylate styrene butadiene rubber (XSBR) polymer on jute yarns, thereby improving the mechanical properties of textile-reinforced cementitious composite (TRCC). An experimental investigation on the use of cellulose microcrystals and nanofibrils as additives to XSBR admixture was conducted. Four...

Context Complementary procedures have been proposed to improve the endodontic retreatments. Aim The aim of this study was to evaluate, by microcomputed tomography (micro-CT), the dentin wear caused by passive ultrasonic irrigation (PUI) and easy clean (EC) instruments, when used for the final removal of filling material during endodontic retreatme...

Sedimentary carbonate outcrops of the Pirabas Formation at the Bragantina platform in North Brazil represent the exposed portion of the entire carbonate succession in the marine equatorial platform from the subsurface Ilha de Santana Formation (Cretaceous/Maastrichtian-Miocene/Messinian) in the Pará-Maranhão Basin. The transgressive deposits, flood...

Aim To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. Methodology After microtomography analysis for morphological standardizat...

Brachycephalus is a genus of small ground-dwelling anurans, endemic to the Brazilian Atlantic Forest. Recent molecular analyses have corroborated the monophyly of three species groups within this genus ( B. ephippium , B. ephippium , and B. ephippium ). In the meantime, the genus has been targeted as a group with recent taxonomic issues owing to it...

A midpalatal suture contention after rapid maxillary expansion (RME) is a major orthodontic challenge. The objective of this study is to evaluate the effect of systemic simvastatin on suture bone remodeling after disjunction. For that, 15 Wistar rats were used. In 10, orthodontic appliances were installed and activated for 5 days for RME. These ani...

The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups ( n = 20): GEC—EasyClean; GPUI—E1 Irrisonic ultrasonic insert; GXP—XP‐Endo finisher; GPC—conventional irrigation and...

Background Eccentric instruments have been proposed as more effective and less time‐consuming for endodontic instrumentation. Aim To compare biomechanical outcomes of different instrumentation systems and time undertaken for instrumentation in resin prototypes. Design Sixty standardized prototypes of mandibular second primary molars were instrume...

Aim To assess the periapical alveolar bone pattern and the serum levels of proinflammatory cytokines, biochemical markers and metabolites in rats subjected to chronic alcohol and nicotine consumption and induced apical periodontitis. Methodology Twenty‐eight male Wistar rats were divided into four groups: Control, Alcohol, Nicotine and Alcohol+Nic...

In this {work}, the X-ray fluorescence technique was employed to characterize the pictorial materials used in two sculptures from the 18th. In addition, Raman spectroscopy was used to characterize the preparation layers used in the sculptures. {The analyzed sculptures} are carved in wood, with gilding and polychrome, and represent the biblical char...

Treatment and diagnosis in Nuclear Medicine and Radiotherapy require simulators able to mimic the human body to pre-assess the radiation behavior of new techniques and radiopharmaceuticals. Development of such simulators requires materials to behave similarly to the body tissues and with more real shapes to obtain more reliable results. XCT-A and X...

Aim This study compared intracanal removal of filling as well as the frequency and volume of extruded material after retreatment with either HyFlex or Reciproc instruments in mandibular teeth from cadavers. Methodology The root canals of 14 pairs of contralateral single‐rooted teeth in mandibles of cadavers were instrumented with Reciproc R40 and...

This study evaluated the impact of long‐term storage conditions (medium and time) on the development of experimental dentinal microcracks through micro‐computed tomography. Sixty freshly extracted premolars were stored in formalin, water, or dry conditions ( n = 20) and scanned after 72 h, 30 days, 6 months and 3 years of extraction. The effect of...

Context Excessive dentine wear during postremoval can occur due to the adhesion between the cement and the post. Aim The aim is to evaluate dentine wear and microcrack occurrence following the removal of intraradicular fiberglass posts that were previously cemented with two types of resin cement. Methods Distal roots ( n = 38) of lower molars wer...

Ocean acidification (OA) is expected to negatively affect many ecologically important organisms. Here we report the response of Caribbean benthic foraminiferal assemblages to naturally discharging low-pH waters with a composition similar to that expected for the end of the 21st century. At low pH �7.8 and low saturation state with respect to calcit...

The ‘Inverse Square Law’ (ISL)( 1) requires the existence of a point radiation source to be validated, but in some cases where there is more than one source, its use is possible as long as a point is determined where a virtual source can be positioned and from this point the points correspond to the ISL. Ambient dose equivalent rate values were obt...

The book sheds light on medical cyber-physical systems while addressing image processing, microscopy, security, biomedical imaging, automation, robotics, network layers’ issues, software design, and biometrics, among other areas. Hence, solving the dimensionality conundrum caused by the necessity to balance data acquisition, image modalities, diffe...

Leposternon microcephalum is a species belonging to the Amphisbaenia, a group of burrowing reptiles. Amphisbaenia present various morphological and physiological adaptations that allow them to penetrate the ground and live underground, through a system of galleries and permanent chambers that they build themselves. Among the morphological adaptatio...

Objective This study compared the shaping ability of TRUShape and XP-endo Shaper systems on C-shaped root canals replicas using microcomputed tomography (micro-CT). Material and Methods Thirty three-dimensional replicas based on a mandibular second molar classified as C1 type I C-shaped canal were randomly divided into two groups ( n = 15): TRUShap...

The authors studied forty-three beautiful nose ornaments from the Moche tomb of the Lady of Cao, located in the north of Peru, which has been dated to be around 300–400 d.C. Of these items, thirty-nine are composed of a sheet of gold alloy joined together in various manners to a silver alloy sheet, which provides a strong contrast at their interfac...

Brain morphological variation is analysed through virtual endocasts in a highly diversified clade of caviomorph rodents belonging to the family Echimyidae. Diversification in brain size and shape is explored through geometric morphometrics and comparative phylogenetic analyses. The results indicate that brain shape is largely independent of general...

Smart Healthcare System (SHS), whose functions contain the overall and highly connected coordinated operation, must rely on command centers, efficient transportation, healthcare staff, and receiving facilities. Integrated healthcare services, medical security, drug dispensing/supervision/follow-up, public health, and other services aiming to improv...

The DICOM medical imaging (MI) standard aids in sharing imageries across healthcare applications. The JPEG 2000 extends JPEG for therapeutic imaging relying on a Discrete Transformation along with wavelets. Nevertheless, JPEG 2000 is extremely unapt to encode certain visual arrangements and render good-quality 3D reconstruction. This paper analyzes...

The Internet of Medical Things (IoMT) designates the interconnection of communication-enabled medical-grade devices and their integration into wider-scale health networks to improve patients' health. However, because of health-related systems' critical nature, the IoMT still faces numerous challenges, particularly reliability, safety, and security....

Healthcare, as an elementary human entitlement, was not immune to new technology. The advancement of technology has made a substantial contribution to first-rate, on-time, acceptable, and cheap healthcare. Nanotechnology together with the Internet of Nanothings (IoNT) have consistently improved healthcare and significantly affected its evolution, r...

Industry 4.0 (I4S), with its primary empowering Information and Communication Technologies (ICTs), completely changes both services and business worlds in the health domain. The Internet of Medical Things (IoMT), Cloud Computing (CC), Fog Computing (FC), besides Big Data (BD) technologies promote eHealth renovation and further methodical spreading...

Digital twins (DTs) have become progressively more popular in contemporary years and may continue to get snowballing acceptance. This chapter uses the terminology Personal Health Devices (PHDs) as a simplification for the set of healthcare gadgets comprising on-body and in-body devices, i.e., wearables, injectables, implantable, ingestible, and oth...

This chapter examines wireless medical devices within the human body to provide sensing and stimulation functions. A critical literature evaluation focuses on three categories of medical in-body devices, namely, IBs that are a) implanted within the human body (implantables), b) eaten like ordinary tablets (ingestibles), and c) injected into the hum...

In today's healthcare, imaging is used for everything from diagnosis to surgery and follow-ups. Because most imaging modalities are digital, medical image processing must deal with massive data volumes and growing resolution. This text’s main themes are visual medical information and scalability to give effective and efficient responses to numerous...

Atmospheric particulate matter (PM) is considered to be a set of pollutants suspended in the air, from industrial processes, motor vehicle exhaust, resuspended street dust, biomass burning, and others. Among the toxic chemical compounds, PM is considered contaminants of great importance for researchers, as they offer harmful effects to humans, faun...

The oil industries have as main problem in their activities of formation of scales containing material of the naturally occurring radioactive material (NORM) type on the internal walls of pipes and in some equipment that make up the process lines plant. This NORM can contribute to the exposure of workers during routine activities, either through ex...

The continuous rise in hydrocarbon demand, the production decline in conventional oilfields, and the remarkable improvement in extraction methods have allowed the hydrocarbon industry and subsequently, geoscientists, to turn to studies on both unconventional and mature fields with untapped potential. In such reservoirs, the application of advanced...

Non-marine carbonates are not fully understood from several points of view, including facies and petrophysics (porosity and permeability), as well as their controlling processes The Hard Cap of the Mupe Member in the Purbeck Limestone Group of the Wessex Basin contains thrombolites presenting varying porosity degrees. This paper aims to carry out a...

The impact of microplastics (MPs) on the environment is a major concern that affects not only marine life but also the entire ecosystem. MPs are defined as tiny artificial polymer-based particles, measuring less than 5 mm in length. The impact of these compounds on human health concerns the metabolic alterations, reproductive disorders, neurologica...

Objective To compare the agreement of images in white light (WL), fluorescence (FL), and digital radiographs (DR), on the diagnosis and treatment decisions for occlusal caries lesions against a micro-CT gold standard. Material and Methods Ten extracted third molars, with enamel and/or dentin caries (ICDAS 2-4), were included. Occlusal surface imag...

An evolutionary paradox on threadsnakes: Phenotypic and molecular evidence reveal a new and remarkably polymorphic species of Siagonodon Abstract Threadsnakes are known for their conserved external morphology and historically controversial systematics, challenging taxo-nomic, biogeographic and evolutionary researches in these fields. Recent morphol...

This research aimed to improve the impregnation of XSBR (Carboxylate Styrene Butadiene Rubber) polymer on jute yarns, and hence the mechanical properties of a TRCC (Textile-Reinforced Cementitious Composite). Thus, an experimental investigation on the use of microcrystalline and nanofibrillated cellulose as additives to XSBR admixture was carried o...

Over the lifetime of an animal, metabolic processes in the body maintain bone tissues in a dynamic state of equilibrium. After the death of the organism, bone tissues undergo diagenesis, an intense transformation that affects its physicochemical constitution. Although many recent works have greatly contributed to the understanding of the processes...

Indiana limestone is composed mainly of calcite and aragonite minerals, which are different crystalline forms of calcium carbonate. Due to its composition of almost pure calcium carbonate (around 97%), it is widely used in the petroleum industry as a standard porous media for laboratory experiments with a huge scope in industrial applications. A me...

The oil and gas industries are the largest producers of NORM wastes that are continuously generated during production and extraction activities. In addition, an increasing trend is observed in waste production worldwide due to the decommissioning of oil platforms. The problem is that most of these wastes are in activity concentration levels above t...

The growing global energy demand requires solutions that improve energy efficiency in all sectors. The civil construction sector is responsible for a large part of global energy consumption. In this context, phase change materials (PCMs) can be incorporated into construction materials to improve the energy efficiency of buildings. The purpose of th...

Bread is one of the oldest foods of mankind, and among them, the sandwich bread is worldwide known and used. In this study we used the non‐destructive computed microtomography technique (microCT) to evaluate the behavior of bread structure over weeks after the production. In addition, the influence of the storage location of the sandwich bread, we...

This study aimed at evaluating the mineral variation induced by polyalkenoate cements in residual dentine after different caries removal methods. Ten extracted sound molars were selected, and five cavities were prepared on the occlusal surface of each specimen. Carious lesions were generated using a microbial protocol, while the caries removal was...

The culture of coffee is very important in Brazilian scenery. Brazil is the world's largest coffee producer, responsible for 30% of the planet's production, and it is among the 15 largest coffee consuming nations. More and more, consumers look for better quality of coffee, and the presence of determinate composts would prejudice the health of the c...

In this study, the characterization of the “Santa Luzia” statue was carried out through three non‐destructive X‐ray techniques: X‐ray Fluorescence (XRF), Digital Radiography (DR), and Computed Tomography (CT). The wooden statue dates from the 18th century. It was carved in Portugal and is currently located at the Santa Luzia church—one of the oldes...

Background: The present study assessed the quality of images and the presence of marginal gaps on cone-beam computed tomography (CBCT) images of teeth restored with all-ceramic and metal-ceramic crowns and compared the gap sizes observed on CBCT images with those obtained on micro-CT images. Methods: Thirty teeth restored with metal-ceramic and...

Background and objectives: Periodontitis is a highly prevalent disease in psychiatric patients, including those undergoing symptomatic treatment with second-generation antipsychotics. Some of these drugs, such as clozapine (CLO) and olanzapine (OLA), have prominent metabolic effects such as weight gain, hyperglycemia, and dyslipidemia, which are r...

The Standard Thermal Neutron Flux Unit, TNF2, in (LNMRI/IRD)(1,2), was built for neutron detector and survey meter calibrations. The facility's fluence is achieved by moderation of four 241Am-Be with a graphite core and paraffin/graphite blocks surrounding it. Due to the small channel dimensions, it is impossible to calibrate personal dosemeters an...

Here, we provide information on the diet of Stereocyclops incrassatus using high resolution microcomputed tomography images of a preserved museum specimen. The tomography of S. incrassatus (CFBH 22911), collected in the Municipality of Linhares, Espírito Santo, in southeastern Brazil, revealed the consumption of a worker ant of the genus Ectatomma...

In this work, the pigments and ground layers of the Saint John the Evangelist painting were analyzed using the techniques of computed radiography, X-ray fluorescence (XRF), and micro-Raman spectroscopy. The painting was purchased by a collector at auction as a 19th-century work of art of unknown authorship. XRF analyzes were performed with a voltag...

Concrete is widely used in the world and is the main material for civil construction. Due to its properties, it has different uses such as structural, filling and shielding. The aim of this work is to compare experimental and theoretical mass attenuation coefficient for concrete with different traits and determine the one with the best performance....

Electronic devices are getting smaller each time and the technology, increasingly complex. Commonly found problems such as reflow soldering and open solder connections, which are mostly difficult to detect by conventional means like X-ray images or physical cut on the transverse section. Along with the challenge of finding these flaws, there are al...

Ocean acidification (OA) is expected to negatively affect many ecologically important organisms. Here we report the response of Caribbean benthic foraminiferal assemblages to naturally discharging low-pH waters with a composition similar to that expected for the end of the 21st century. At low pH ∼ 7.8 and low saturation state with respect to calci...

Experimental research on the direct shear behavior of fiber-reinforced concrete is often carried out using prisms molded with specific dimensions for a standardized test. However, the flow of fresh concrete in these molds can be different than in the case of a full-scale structural element. This is important considering that the flow direction high...

This study applied, radiocarbon dating to charcoal and mollusk samples from Sernambetiba and Amourins archaeological sites in the Northeast region of Guanabara Bay, in the state of Rio de Janeiro, Brazil, to assess the marine radiocarbon reservoir effect (MRE) of this area, being applied for the correction of the marine samples ages. The results fo...

Toadlets of the genus Brachycephalus are endemic to the Brazilian Atlantic Rainforest, where they inhabit the forest floor leaf litter. These miniaturized frogs are commonly known as flea-toads or pumpkin toadlets depending on their phenotypic characteristics. Herein, we describe a new species of the genus Brachycephalus from montane forests (97012...

Transmission radiographs acquired with conical beams have their attenuation maps deformed due to the variable thickness travelled by the radiation in the inspected object, a phenomenon which darkens the image outwards its center jeopardizing thus a proper equalization. In the field of welding radiography, this process is especially detrimental for...