Self-sustained n-Type Memory Transistor Devices Based on Natural Cellulose Paper Fibers

Rodrigo Martins,Luís Pereira,Pedro Barquinha,Nuno Correia,Gonçalo Gonçalves,Isabel Ferreira,Carlos Dias,Elvira Fortunato,N. Correia,M. Dionísio,M. Silva 한국정보디스플레이학회 2009 Journal of information display Vol.10 No.4

Reported herein is the architecture for a nonvolatile n-type memory paper field-effect transistor. The device was built via the hybrid integration of natural cellulose fibers (pine and eucalyptus fibers embedded in resin withionic additives), which act simultaneously as substrate and gate dielectric, using passive and active semiconductors, respectively, as well as amorphous indium zinc and gallium indium zinc oxides for the gate electrode and channel layer, respectively. This was complemented by the use of continuous patterned metal layers as source/drain electrodes.

Self-sustained n-Type Memory Transistor Devices Based on Natural Cellulose Paper Fibers

Martins, Rodrigo,Pereira, Luis,Barquinha, Pedro,Correia, Nuno,Goncalves, Goncalo,Ferreira, Isabel,Dias, Carlos,Correia, N.,Dionisio, M.,Silva, M.,Fortunato, Elvira The Korean Infomation Display Society 2009 Journal of information display Vol.10 No.4

Reported herein is the architecture for a nonvolatile n-type memory paper field-effect transistor. The device was built via the hybrid integration of natural cellulose fibers (pine and eucalyptus fibers embedded in resin with ionic additives), which act simultaneously as substrate and gate dielectric, using passive and active semiconductors, respectively, as well as amorphous indium zinc and gallium indium zinc oxides for the gate electrode and channel layer, respectively. This was complemented by the use of continuous patterned metal layers as source/drain electrodes.

Design and evaluation of a head-mounted display for immersive 3D teleoperation of field robots

Martins, Henrique,Oakley, Ian,Ventura, Rodrigo Cambridge University Press 2015 Robotica Vol.33 No.10

<B>SUMMARY</B><P>This paper describes and evaluates the use of a head-mounted display (HMD) for the teleoperation of a field robot. The HMD presents a pair of video streams to the operator (one to each eye) originating from a pair of stereo cameras located on the front of the robot, thus providing him/her with a sense of depth (stereopsis). A tracker on the HMD captures 3-DOF head orientation data which is then used for adjusting the camera orientation by moving the robot and/or the camera position accordingly, and rotating the displayed images to compensate for the operator's head rotation. This approach was implemented in a search and rescue robot (RAPOSA), and it was empirically validated in a series of short user studies. This evaluation involved four experiments covering two-dimensional perception, depth perception, scene perception, and performing a search and rescue task in a controlled scenario. The stereoscopic display and head tracking are shown to afford a number of performance benefits. However, one experiment also revealed that controlling robot orientation with yaw input from the head tracker negatively influenced task completion time. A possible explanation is a mismatch between the abilities of the robot and the human operator. This aside, the studies indicated that the use of an HMD to create a stereoscopic visualization of the camera feeds from a mobile robot enhanced the perception of cues in a static three-dimensional environment and also that such benefits transferred to simulated field scenarios in the form of enhanced task completion times.</P>

The effect of individualization of fiberglass posts using bulk-fill resin-based composites on cementation: an in vitro study

Rodrigo Barros Esteves Lins,Jairo Matozinho Cordeiro,Carolina Perez Rangel,Thiago Bessa Marconato Antunes,Luís Roberto Marcondes Martins 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.4

Objectives This study evaluated the bond strength of various fiberglass post cementation techniques using different resin-based composites. Materials and Methods The roots from a total of 100 bovine incisors were randomly assigned to 5 treatment groups: G1, post + Scotchbond Multi-Purpose (SBMP) + RelyX ARC luting agent; G2, relined post (Filtek Z250) + SBMP + RelyX ARC; G3, individualized post (Filtek Z250) + SBMP; G4, individualized post (Filtek Bulk-Fill) + SBMP; G5, individualized post (Filtek Bulk-Fill Flow) + SBMP. The samples were subjected to the push-out (n = 10) and pull-out (n = 10) bond strength tests. Data from the push-out bond strength test were analyzed using 2-way analysis of variance (ANOVA) with the Bonferroni post hoc test, and data from the pull-out bond strength test were analyzed using 1-way ANOVA. Results The data for push-out bond strength presented higher values for G2 and G5, mainly in the cervical and middle thirds, and the data from the apical third showed a lower mean push-out bond strength in all groups. No significant difference was noted for pull-out bond strength among all groups. The most frequent failure modes observed were adhesive failure between dentine and resin and mixed failure. Conclusions Fiberglass post cementation using restorative and flowable bulk-fill composites with the individualization technique may be a promising alternative to existing methods of post cementation.

Chitosan-Hydroxyapatite Scaffold for Tissue Engineering in Experimental Lumbar Laminectomy and Posterolateral Spinal Fusion in Wistar Rats

Martin Rodríguez-Vázquez,Rodrigo Ramos-Zúñiga 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.2

Study Design: Experimental study with an animal model. Purpose: To evaluate the role of a chitosan and hydroxyapatite composite for spinal fusion in a lumbar experimental model based on regenerative tissue engineering principles. Overview of Literature: Chitosan and hydroxyapatite represent an alternative biodegradable implant material for tissue engineering and regeneration. The combination of chitosan and hydroxyapatite in a 20:80 ratio could potentiate their individual properties as an implantable composite for experimental laminectomy. Methods: Phase I: design and synthesis of a porous composite scaffold composed of chitosan-hydroxyapatite using a freeze drying technique. Phase II: experimental microsurgical lumbar laminectomy at L5. A total of 35 Wistar rats were categorized into three experimental groups: control (laminectomy alone), experimental (laminectomy with implant), and reference (intact spine) (n=5 per group). Postoperative structural and functional evaluations were performed using computed tomography scans. In addition, radiologic, clinical, histological, and immunohistochemical microstructures were evaluated. Results: At the laminectomy site, the composite implant induced bone regeneration, which was observed in the axial reconstruction of the rat lumbar spine in all cases. Biomechanical changes in the lumbar spine were observed by radiology in both groups after the surgery. The posterolateral space was covered by a bone structure in the treated spine, a condition not seen in the control group. The range of motion was 7.662°±0.81° in the scaffold group versus 20.72°±3.47° in the control group. Histological findings revealed qualitatively more bone tissue formation in the implant group. Conclusions: A composite of chitosan-hydroxyapatite at a 20:80 ratio induced bone formation after experimental laminectomy in rats and led to spinal fusion, which was assessed by radiology and biomechanical tests. No functional complications in posture or walking were observed at 90 days post-surgery, despite biomechanical changes in the spine.

CAN THE WORLD TRADING SYSTEM ACCOMMODATE MORE EAST ASIAN STYLE EXPORTERS ?

RODRIGO, G. CHRIS,MARTIN, WILL 한국국제경제학회 1997 International Economic Journal Vol.11 No.4

The effect of individualization of fiberglass posts using bulk-fill resin-based composites on cementation: an in vitro study

Lins, Rodrigo Barros Esteves,Cordeiro, Jairo Matozinho,Rangel, Carolina Perez,Antunes, Thiago Bessa Marconato,Martins, Luis Roberto Marcondes The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.4

Objectives: This study evaluated the bond strength of various fiberglass post cementation techniques using different resin-based composites. Materials and Methods: The roots from a total of 100 bovine incisors were randomly assigned to 5 treatment groups: G1, post + Scotchbond Multi-Purpose (SBMP) + RelyX ARC luting agent; G2, relined post (Filtek Z250) + SBMP + RelyX ARC; G3, individualized post (Filtek Z250) + SBMP; G4, individualized post (Filtek Bulk-Fill) + SBMP; G5, individualized post (Filtek Bulk-Fill Flow) + SBMP. The samples were subjected to the push-out (n = 10) and pull-out (n = 10) bond strength tests. Data from the push-out bond strength test were analyzed using 2-way analysis of variance (ANOVA) with the Bonferroni post hoc test, and data from the pull-out bond strength test were analyzed using 1-way ANOVA. Results: The data for push-out bond strength presented higher values for G2 and G5, mainly in the cervical and middle thirds, and the data from the apical third showed a lower mean push-out bond strength in all groups. No significant difference was noted for pull-out bond strength among all groups. The most frequent failure modes observed were adhesive failure between dentine and resin and mixed failure. Conclusions: Fiberglass post cementation using restorative and flowable bulk-fill composites with the individualization technique may be a promising alternative to existing methods of post cementation.

The pancreas as a target of metastasis from renal cell carcinoma: Results of surgical treatment in a single institution

Juan Glinka,Rodrigo Sanchez Claria,Victoria Ardiles,Eduardo de Santibanes,Juan Pekolj,Martin de Santibanes,Oscar Mazza 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.3

Backgrounds/Aims: Metastasis in the pancreatic gland is infrequent, representing between 2-5% of the tumors that affect this organ. However, secondary lesions of clear cell renal carcinoma (CCRC) can occur mainly in this location and it is frequently the only site of dissemination. Treatment of choice is resection in surgically fit patients, as it has been shown that it improves the quality of life and prognosis substantially. We retrospectively reviewed the clinical data of patients with pancreatic resections for metastatic CCRC since there are no reports of the treatment modality of this singular entity in Argentina. Methods: Retrospective cohort analysis over a 10-year period including eight patients who underwent pancreatic resection for metastatic CCRC. Results: 75% of patients were male with an average age of 65.5 years. The pancreatic surgery occurred at a median time of 9.2 years (1-24.8) from the renal operation. The pancreatic lesions were mostly solitary and asymptomatic. A pancreaticoduodenectomy (PD) was performed in 4 patients (50%). Distal pancreatectomy (DP) was performed in 3 patients (37.3%) and one patient (12.5%) underwent a total pancreaticoduodenectomy. All the patients presented a confirmatory biopsy of pancreatic metastasis of CCRC. Complications were recorded in 3 patients (42.85%). No intraoperative or postoperative mortality was registered. With a median follow-up of 45 months, three patients presented recurrence at 32, 46 and 51 months, respectively. Only one patient showed death due to recurrence at 7.8 month. Conclusions: CCRC pancreatic metastases treated surgically have a low morbidity and mortality rate in high volume centers, showing excellent long-term survival.

Influence of inorganic composition and filler particle morphology on the mechanical properties of self-adhesive resin cements

Santi Marina Rodrigues,Lins Rodrigo Barros Esteves,Sahadi Beatriz Ometto,Denucci Giovanna Corrêa,Soffner Gabriela,Martins Luís Roberto Marcondes 대한치과보존학회 2022 Restorative Dentistry & Endodontics Vol.47 No.3

Objectives This study aimed to evaluate the influence of inorganic composition and filler particle morphology on the mechanical properties of different self-adhesive resin cements (SARCs). Materials and Methods Three SARCs including RelyX Unicem-2 (RUN), Maxcem Elite (MAX), and Calibra Universal (CAL) were tested. Rectangular bar-shaped specimens were prepared for flexural strength (FS) and flexural modulus (FM) and determined by a 3-point bending test. The Knoop microhardness (KHN) and top/bottom microhardness ratio (%KHN) were conducted on the top and bottom faces of disc-shaped samples. Sorption (Wsp) and solubility (Wsl) were evaluated after 24 hours of water immersion. Filler morphology was analyzed by scanning electron microscopy and X-ray energy dispersive spectroscopy (EDS). FS, FM, %KHN, Wsp, Wsl, and EDS results were submitted to 1-way analysis of variance and Tukey’s post-hoc test, and KHN also to paired t-test (α = 0.05). Results SARC-CAL presented the highest FS value, and SARC-RUN presented the highest FM. SARC-MAX and RUN showed the lowest Wsp and Wsl values. KHN values decreased from top to bottom and the SARCs did not differ statistically. Also, all resin cements presented carbon, aluminum, and silica in their composition. SARC-MAX and RUN showed irregular and splintered particles while CAL presented small and regular size particles. Conclusions A higher mechanical strength can be achieved by a reduced spread in grit size and the filler morphology can influence the KHN, as well as photoinitiators in the composition. Wsp and Wsl can be correlated with ions diffusion of inorganic particles.

An optimized index for cold tolerance assessment in rice during germination and early seedling stage

Monzón Daisy Leticia Ramirez,Cantero Jorge,Danielowski Rodrigo,da Luz Viviane Kopp,Venske Eduardo,Mota Monalize Salete,da Silva Raissa Martins,de Oliveira Victoria Freitas,de Oliveira Antonio Costa,de 한국작물학회 2023 Journal of crop science and biotechnology Vol.26 No.2

Cold tolerance at germination and seedling stage is one of the most seeked traits in Southern Brazilian rice (Oryza sativa L.) cultivars, thus, the availability of improved methods for germplasm assessment is of high importance for breeding programs. The aim of this study was to validate an optimized Average Tolerance Index (ATI) for rice germplasm assessment under cold at germination and early seedling stage. A diverse panel composed by 124 rice accessions was assayed. Four genotypes with known performance under cold were used as controls (two tolerant and two sensitive). The genotypes were sown in roll papers, and evaluated at 13 °C for 28 days (cold stress) and 25 °C for seven days (control). Four traits were measured, germination percentage, coleoptile length, root length and shoot length, which were converted in terms of relative perfor‑ mance (cold/control). A PCA analysis was carried out. The ATI was calculated as a linear combination of all trait’s relative performance, weighted by the importance of each trait in explaining the genetic variability in the set, through including the PC1 vectors as trait coefcients. K means was applied for genotype classifcation. The panel showed expressive genetic variability for performance under low temperature. The ATI successfully distinguished the controls regarding their cold tolerance and allowed the formation of four classes of genotypes, sensitive, moderately sensitive, moderately tolerant and tolerant. The assessment of rice germplasm for cold tolerance at germination and seedling stage through ATI is a viable alternative for the identifcation of tolerant genotypes.