Cast Aluminum Surface Reinforced with Carbon Nanotube via Solubilization Treatment

Paulo R. O. Brito,Cristhian R. L. Loayza,Mário E. S. Sousa,Eduardo M. Braga,Rômulo S. Angélica,Simone P. A. da Paz,Marcos A. L. Reis 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.3

Carbon nanotubes (CNTs) are noteworthy, as they reinforce the metallic matrix, due to mechanical properties, such asthe ~ 1.0 TPa Young module. To improve the maintenance of the commercially pure aluminum surface, multi-walled carbonnanotubes were incorporated into the aluminum surface with heat treatment by solid solubilization, in order to improvethe surface properties of aluminum. The aluminum samples were chemically attacked for 30, 60 and 120 s and placed in acontainer with CNTs, being subjected to a temperature of 640 °C for 1 h. Then, the roughness was evaluated by a roughnessmeter for morphology in the scanning electron microscopy. An intensity of aggregation of CNTs was evaluated by XRD, andthe Raman Spectra has evaluated the transfer of charge to the matrix. Microhardness was performed to evaluate the influenceof the incorporation of CNTs in the matrix. The results obtained show that the incorporation of CNTs in the aluminummatrix increases the hardness in approximately 20% of the surface, in comparison with the control sample. The process ofincorporating CNTs into the aluminum matrix by solubilization is a promising, simple and inexpensive alternative to improvethe durability of the aluminum surface.

Finite element analysis of helmeted oblique impacts and head injury evaluation with a commercial road helmet

Fábio A.O. Fernandes,R.J. Alves de Sousa 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.5

In this work, the safety performance of a commercial motorcycle helmet already placed on the market is assessed. The assessed motorcycle helmet is currently homologated by several relevant motorcycle standards. Impacts including translational and rotational motions are accurately simulated through a finite element numerical framework. The developed model was validated against experimental results: firstly, a validation concerning the constitutive model for the expanded polystyrene, the material responsible for energy absorption during impact; secondly, a validation regarding the acceleration measured at the headform's centre of gravity during the linear impacts defined in the ECE R22.05 standard. Both were successfully validated. After model validation, an oblique impact was simulated and the results were compared against head injury thresholds in order to predict the resultant head injuries. From this comparison, it was concluded that brain injuries such as concussion and diffuse axonal injury may occur even with a helmet certified by the majority of the motorcycle helmet standards. Unfortunately, these standards currently do not contemplate rotational components of acceleration. Conclusion points out to a strong recommendation on the necessity of including rotational motion in forthcoming motorcycle helmet standards and improving the current test procedures and head injury criteria used by the standards, to improve the safety between the motorcyclists.

Finite element analysis of helmeted oblique impacts and head injury evaluation with a commercial road helmet

Fernandes, Fabio A.O.,de Sousa, R.J. Alves Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.5

In this work, the safety performance of a commercial motorcycle helmet already placed on the market is assessed. The assessed motorcycle helmet is currently homologated by several relevant motorcycle standards. Impacts including translational and rotational motions are accurately simulated through a finite element numerical framework. The developed model was validated against experimental results: firstly, a validation concerning the constitutive model for the expanded polystyrene, the material responsible for energy absorption during impact; secondly, a validation regarding the acceleration measured at the headform's centre of gravity during the linear impacts defined in the ECE R22.05 standard. Both were successfully validated. After model validation, an oblique impact was simulated and the results were compared against head injury thresholds in order to predict the resultant head injuries. From this comparison, it was concluded that brain injuries such as concussion and diffuse axonal injury may occur even with a helmet certified by the majority of the motorcycle helmet standards. Unfortunately, these standards currently do not contemplate rotational components of acceleration. Conclusion points out to a strong recommendation on the necessity of including rotational motion in forthcoming motorcycle helmet standards and improving the current test procedures and head injury criteria used by the standards, to improve the safety between the motorcyclists.

SPIF-A: on the development of a new concept of incremental forming machine

R.J. Alves de Sousa,J.A.F. Ferreira,J.B. Sá de Farias,J.N.D. Torrão,D.G. Afonso,M.A.B.E Martins 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5

This paper presents the design and project of an innovative concept for a Single PointIncremental Forming (SPIF) Machine. Nowadays, equipment currently available for conducting SPIF resultmostly from the adaptation of conventional CNC machine tools that results in a limited range of applicationsin terms of materials and geometries. There is also a limited market supply of equipment dedicated toIncremental Sheet Forming (ISF), that are costly considering low batches, making it unattractive forindustry. Other factors impairing a quicker spread of SPIF are large forming times and poor geometricalaccuracy of parts. The following sections will depict the development of a new equipment, designed toovercome some of the limitations of machines currently used, allowing the development of a sounding basisfor further studies on the particular features of this process. The equipment here described possesses sixdegrees-of freedom for the tool, for the sake of improved flexibility in terms of achievable tool-paths and anextra stiffness provided by a parallel kinematics scheme. A brief state of the art about the existing SPIFmachines is provided to support the project’s guidelines.

SPIF-A: on the development of a new concept of incremental forming machine

Alves de Sousa, R.J.,Ferreira, J.A.F.,Sa de Farias, J.B.,Torrao, J.N.D.,Afonso, D.G.,Martins, M.A.B.E. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5

This paper presents the design and project of an innovative concept for a Single Point Incremental Forming (SPIF) Machine. Nowadays, equipment currently available for conducting SPIF result mostly from the adaptation of conventional CNC machine tools that results in a limited range of applications in terms of materials and geometries. There is also a limited market supply of equipment dedicated to Incremental Sheet Forming (ISF), that are costly considering low batches, making it unattractive for industry. Other factors impairing a quicker spread of SPIF are large forming times and poor geometrical accuracy of parts. The following sections will depict the development of a new equipment, designed to overcome some of the limitations of machines currently used, allowing the development of a sounding basis for further studies on the particular features of this process. The equipment here described possesses six-degrees-of freedom for the tool, for the sake of improved flexibility in terms of achievable tool-paths and an extra stiffness provided by a parallel kinematics scheme. A brief state of the art about the existing SPIF machines is provided to support the project's guidelines.

miR-30-HNF4γ and miR-194-NR2F2 regulatory networks contribute to the upregulation of metaplasia markers in the stomach

Sousa, Josane F,Nam, Ki Taek,Petersen, Christine P,Lee, Hyuk-Joon,Yang, Han-Kwang,Kim, Woo Ho,Goldenring, James R BMJ Publishing Group Ltd 2016 Gut Vol.65 No.6

<P>Objective Intestinal metaplasia and spasmolytic polypeptide-expressing metaplasia (SPEM) are considered neoplastic precursors of gastric adenocarcinoma and are both marked by gene expression alterations in comparison to normal stomach. Since miRNAs are important regulators of gene expression, we sought to investigate the role of miRNAs on the development of stomach metaplasias. Design We performed miRNA profiling using a quantitative reverse transcription-PCR approach on laser capture microdissected human intestinal metaplasia and SPEM. Data integration of the miRNA profile with a previous mRNA profile from the same samples was performed to detect potential miRNA-mRNA regulatory circuits. Transfection of gastric cancer cell lines with selected miRNA mimics and inhibitors was used to evaluate their effects on the expression of putative targets and additional metaplasia markers. Results We identified several genes as potential targets of miRNAs altered during metaplasia progression. We showed evidence that HNF4 gamma (upregulated in intestinal metaplasia) is targeted by miR-30 and that miR-194 targets a known co-regulator of HNF4 activity, NR2F2 (downregulated in intestinal metaplasia). Intestinal metaplasia markers such as VIL1, TFF2 and TFF3 were downregulated after overexpression of miR-30a in a HNF4 gamma-dependent manner. In addition, overexpression of HNF4 gamma was sufficient to induce the expression of VIL1 and this effect was potentiated by downregulation of NR2F2. Conclusions The interplay of the two transcription factors HNF4 gamma and NR2F2 and their coordinate regulation by miR-30 and miR-194, respectively, represent a miRNA to transcription factor network responsible for the expression of intestinal transcripts in stomach cell lineages during the development of intestinal metaplasia.</P>

A quality by design approach in oral extended release drug delivery systems: where we are and where we are going?

Sousa A. S.,Serra J.,Estevens C.,Costa R.,Ribeiro A. J. 한국약제학회 2023 Journal of Pharmaceutical Investigation Vol.53 No.2

Background Oral extended release (ER) delivery systems have quickly gained increasing importance because of their ability to maintain drug levels in the blood more consistently, reducing side effects and improving patient compliance. The complexity of ER formulation leads to additional development challenges in the fulfilment of quality-related regulatory requirements. Despite their challenging properties, the potential of ER system formulation and process development can be better exploited by applying quality by design (QbD) approaches and advanced modeling techniques such as machine learning (ML). Area covered This review provides a comprehensive overview of QbD concepts applied to oral ER delivery systems, clarifying the impact of raw materials and process variables on critical quality attributes (CQAs). Moreover, data science coupled with ML algorithms is also elucidated in this article as a potential tool for predicting and optimizing ER formulation design and manufacturing processes. Expert opinion QbD, as a scientific and risk-based approach, provides a comprehensive understanding of oral ER drug delivery systems improving product quality and reducing postapproval changes. Enabling QbD with ML-driven pharmaceutical development can provide an opportunity to move toward risk mitigation for efficient ER tablet formulation and process development. However, there are some barriers to overcome in the way of adopting QbD concepts. The key issues are the lack of understanding and the gap between industries and regulatory authorities concerning the scientific principles and terms beyond QbD, which can create an obstacle during the approval process. Furthermore, it is generally believed that the resources and time invested in applying QbD tools are not cost-effective during constant and continuous improvement. Today, it is time to realize that a multidisciplinary understanding of the formulation and manufacturing process is as important as achieving the final result.

Characterization of agar from <i>Gracilaria tikvahiae</i> cultivated for nutrient bioextraction in open water farms

Rocha, Cristina M.R.,Sousa, Ana M.M.,Kim, Jang K.,Magalhã,es, Jú,lia M.C.S.,Yarish, Charles,Gonç,alves, Maria do Pilar Elsevier 2019 Food hydrocolloids Vol.89 No.-

<P><B>Abstract</B></P> <P> <I>Gracilaria tikvahiae</I>, an endemic western North Atlantic red alga, was cultivated for nutrient bioextraction in urbanized estuarine waters in Long Island Sound and the Bronx River Estuary, USA. This study assesses the feasibility of an integrated approach of using <I>G. tikvahiae</I> produced in this bioextraction system as sustainable biomass source for agar production. Agars were extracted after alkaline pre-treatment and characterized in terms of gelling strength, chemical composition, chemical structure and gel structure. Results indicated that this seaweed performed similar to other cultivated <I>Gracilaria</I> in terms of extraction yield and gelling strength of the agar. Differences between sites were not significant in terms of agar gel strength, though yield was higher at Long Island Sound. The extracted agars were sulfated, methylated and with no detectable pyruvate substituents. It is possible to use an integrated strategy of nutrient bioextraction in urbanized estuarine waters and agar exploitation with <I>G. tikvahiae</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Agar was successfully extracted from <I>G. tikvahiae</I> used in the nutrient bioextraction systems in urbanized coastal waters. </LI> <LI> Extracted agar performance was similar to other <I>Gracilaria</I> agars. </LI> <LI> There were no significant differences in the gelling strength between the two cultivation sites. </LI> <LI> NMR profile and gel structure of the extracted agars was analyzed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effectiveness of Acupuncture in Dental Surgery: A Randomized, Crossover, Controlled Trial

Maria LB. Gil,Luide M.R.F. Marinho,Marcio de Moraes,Ronaldo S. Wada,Francisco C. Groppo,Jorge E. Sato,Maria L.R. de Sousa 사단법인약침학회 2020 Journal of Acupuncture & Meridian Studies Vol.13 No.3

Objectives: The objective of this crossover clinical study was to evaluate the effectiveness of Energy Regulation with Acupuncture in clinical occurrences in impacted lower third molar surgeries. Methods: The sample consisted of 22 patients with two impacted third molars, in symmetrical position; divided into two groups: Test Group (TG) with Real Energy Regulation Group and Sham Group (SG) with Acupuncture without Energy Regulation function. The extraction was performed 30 days apart. Energy flow (Ryodoraku Method) and energy regulation performed before extraction were measured. Heart Rate (HR) and Blood Pressure (BP) were evaluated before and after energy regulation and after surgery, residual edema was measured by facial measurements (angle of the mandible to tragus (A-T); angle of the mandible to labial commissure (A-LC); angle of the mandible to the wing of the nose (A-WN); angle of the mandible to the corner of the eye (A-CE); angle of the mandible to the chin (A-C); and mouth opening by the interincisal distance, before and after seven days of surgery. To quantify intraoperative bleeding (ml), blood was aspirated along with the saline solution using a portable vacuum pump adaptor. The amount of saline solution used was subtracted from the final amount of aspirated fluid. Results: Mean of bleeding was lower in TG (p = 0.0392). There were significant differences between groups in facial distances: A-LC (p = 0.010), A-WN (p = 0.030) and A-C (p = 0.008). Conclusion: Energy regulation with real acupuncture was effective in reducing postoperative residual edema and intraoperative bleeding.

Preparation and characterization of polymer/layered silicate pharmaceutical nanobiomaterials using high clay load exfoliation processes

Jaqueline Correia Villac¸a,Luiz Cla´udio R. Pereira da Silva,Luisa Helena Falca˜o Barbosa,Carlos Rangel Rodrigues,Luiz Marcelo Lira,Fla´ via Almada do Carmo,Valeria Pereira de Sousa,Maria Ineˆs Bruno 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

The purpose of this study was to prepare and characterize lamellar silicate nanocomposites usingexfoliation processes, high clay load and polyvinylpyrrolidone (PVP), ethylcellulose (EC) andpolyquaternium-H (PQH). The clays (sodium montmorillonite, Viscogel S4TM, S7TM and B8TM) werepre-treated with ultrasonic energy in order to increase clay exfoliation yields. Polymeric nanocompositeswere characterized by XRPD, DSC, TGA, DLS and NMR. The results revealed a new exfoliationmethod and new intercalated nanocomposites. High clay load was used to obtain the nanocomposites,which enables its application at an industrial scale. These nanocomposites could be broadly appliedacross the pharmaceutical, medical and food industries.