60 results match your criteria: "Nuclear and Energy Research Institute - IPEN-CNEN[Affiliation]"

Direct conversion of methane to C compounds by oxidative and nonoxidative coupling reactions has been intensively studied in the past four decades; however, because these reactions have intrinsic severe thermodynamic constraints, they have not become viable industrially. Recently, with the increasing availability of inexpensive "green electrons" coming from renewable sources, electrochemical technologies are gaining momentum for reactions that have been challenging for more conventional catalysis. Using solid-state membranes to control the reacting species and separate products in a single step is a crucial advantage.

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Polymeric nanoparticles acting as sources of selenium (Se) are currently an interesting topic in cancer chemotherapy. In this study, polyglycerol dendrimer (DPGLy) was functionalized with seleno-methyl-selenocysteine (SeMeCys) by means of Steglich esterification with 4-dimethylaminopyridine/(l-ethyl-3-(3-dimethylaminopropyl)carbodiimide) (EDC/DMAP) and cerium chloride as cocatalyst in acetonitrile at quantitative yields of 98 ± 1%. The SeMeCys coupling DPGLy efficiency vs.

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This work investigated the effect of photobiomodulation therapy (PBM) combined with radiotherapy (RT) on triple-negative breast cancer (TNBC)-bearing mice. Female BALB/c mice received 4 T1 cells into a mammary fat pad. Local RT was performed with a total dose of 60 Gy divided into 4 consecutive sessions of 15 Gy.

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ERK1/2 inhibitors have attracted special attention concerning the ability of circumventing cases of innate or log-term acquired resistance to RAF and MEK kinase inhibitors. Based on the 4-aminoquinazoline pharmacophore of kinases, herein we describe the synthesis of 4-aminoquinazoline derivatives bearing a 1,2,3-triazole stable core to bridge different aromatic and heterocyclic rings using copper-catalysed azide-alkyne cycloaddition reaction (CuAAC) as a Click Chemistry strategy. The initial screening of twelve derivatives in tumoral cells (CAL-27, HN13, HGC-27, and BT-20) revealed that the most active in BT-20 cells (25a, IC 24.

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Background: Tetanus toxin blocks the release of the inhibitory neurotransmitters in the central nervous system and causes tetanus and its main form of prevention is through vaccination. The vaccine is produced by inactivation of tetanus toxin with formaldehyde, which may cause side effects. An alternative way is the use of ionizing radiation for inactivation of the toxin and also to improve the potential immunogenic response and to reduce the post-vaccination side effects.

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The control of air pollution remains a challenge to the planning of cities and fossil fuel burning is the main cause of air degradation. Particulate matter (PM) is the contaminant commonly used as an indicator of pollution, but environmental agencies may face difficulties in operating surveillance networks due to the lack of resources and infrastructure. As an alternative to conventional networks, scientific studies have pointed out that nature itself can contribute to the diagnosis and reduction of air pollution.

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Introduction: Radiosynovectomy (RS) with Y-hydroxyapatite (Y-HyA) aims to control knee hemarthrosis in hemophiliac patients to prevent secondary arthropathy. However, knee RS using Sm-hydroxyapatite (Sm-HyA) is considered less suitable due to the lower average soft tissue range and energy of Sm for large joints, such as the knees.

Purpose: The objective of this investigation was to assess the efficacy and safety of knee RS with Sm-HyA, compared to Y-HyA.

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Amphotericin B (Amph-B) is an antifungal drug used intravenously for the treatment of leishmaniasis. Side-effects from Amph-B treatment can arise such as cardiac arrhythmia and renal dysfunctions, which will lead to discontinuation of treatment. Unfortunately, patients in endemic countries do not have access to alternative therapies.

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Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty-four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer).

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The aim of this study was the development of collagen and collagen/auricular cartilage scaffolds for application in dermal regeneration. Collagen was obtained from bovine tendon by a 72 h-long treatment, while bovine auricular cartilage was treated for 24 h and divided into two parts, external (perichondrium, E) and internal (elastic cartilage, I). The scaffolds were prepared by mixing collagen (C) with the internal part (CI) or the external part (CE) in a 3:1 ratio.

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Surface Evaluation of Enamel Etched by Er,Cr:YSGG Laser for Orthodontic Purpose.

J Contemp Dent Pract

March 2020

Department of Physics, School of Dentistry, Federal University of Pernambuco (UFPE), Recife-PE, Brazil, Phone: +55 8121268000, e-mail:

Aim: To compare the effect of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser at different irradiation parameters and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel.

Materials And Methods: Forty bovine incisors were randomly distributed into groups ( = 10): GI: 37% phosphoric acid etching; GII: Er,Cr:YSGG laser etching 19.1 J/cm; GIII: Er,Cr:YSGG, 29.

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Losartan is widely used in clinics to treat cardiovascular related diseases by selectively blocking the angiotensin II type 1 receptors (ATRs), which regulate the renin-angiotensin system (RAS). Therefore, monitoring the physiological and pathological biodistribution of ATR using positron emission tomography (PET) might be a valuable tool to assess the functionality of RAS. Herein, we describe the synthesis and characterization of two novel losartan derivatives PET tracers, [F]fluoroethyl-losartan ([F]FEtLos) and [F]ammoniomethyltrifluoroborate-losartan ([F]AMBFLos).

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Natural triterpenes exhibit a wide range of biological activities. Since this group of secondary metabolites is structurally diverse, effects may vary due to distinct biochemical interactions within biological systems. In this work, we investigated the anticancer-related activities of the quinone-methide triterpene maytenin and its derivative compound 22-β-hydroxymaytenin, obtained from roots cultivated in vitro.

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Novel fluoride and stannous -functionalized β-tricalcium phosphate nanoparticles for the management of dental erosion.

J Dent

January 2020

Department of Restorative Dentistry, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP, 05508-000, Brazil. Electronic address:

Objective: To evaluate the anti-erosive effect of solutions containing β-tricalcium phosphate (β-TCP) nanoparticles functionalized with fluoride or with fluoride plus stannous on enamel and dentin.

Methods: β-TCP nanoparticles were synthesized and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Sixty enamel and dentin specimens were randomly allocated into the groups (n = 10): Control (water); F (NaF, 225 ppm F); F + Sn (NaF + SnCl 800 ppm Sn); F+β-TCP (F+40 ppm β-TCP); F + Sn+β-TCP (F + Sn+40 ppm β-TCP); F + Sn+100β-TCP (F + Sn+100 ppm β-TCP).

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Cutaneous leishmaniasis (CL) is a neglected disease that promotes destructive lesions. Difficulties in treatment are related to accessibility of drugs, resistance and toxicity. Antimicrobial photodynamic therapy (APDT) has been emerging as a promising treatment for CL.

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Article Synopsis
  • An internal consistency test was conducted to evaluate the calculation of coincidence-summing correction factors F for volume sources, using exact equations from three ideal measurement configurations.
  • The test was performed on 33 sets of F values submitted by 21 different teams, with most sets passing the evaluation.
  • However, the results from the quasi-point source approximation did not pass, revealing a qualitative indication of bias in the calculated values of F.
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Nitric oxide-loaded chitosan nanoparticles as an innovative antileishmanial platform.

Nitric Oxide

December 2019

Center for Lasers and Applications, Nuclear and Energy Research Institute (IPEN-CNEN/SP), Av. Prof. Lineu Prestes, 2242, CEP 05508-000, São Paulo, SP, Brazil. Electronic address:

Leishmaniasis is a neglected tropical disease that demands for new therapeutic strategies due to adverse side effects and resistance development promoted by current drugs. Nitric oxide (NO)-donors show potential to kill Leishmania spp. but their use is limited because of their instability.

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The recent clinical adoption of optical coherence tomography (OCT) angiography (OCTA) has enabled non-invasive, volumetric visualization of ocular vasculature at micron-scale resolutions. Initially limited to 3 mm × 3 mm and 6 mm × 6 mm fields-of-view (FOV), commercial OCTA systems now offer 12 mm × 12 mm, or larger, imaging fields. While larger FOVs promise a more complete visualization of retinal disease, they also introduce new challenges to the accurate and reliable interpretation of OCTA data.

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Odd-Even Effect on Luminescence Properties of Europium Aliphatic Dicarboxylate Complexes.

Chemphyschem

August 2019

Department of Fundamental Chemistry Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, São Paulo-SP, 05508-000, Brazil.

Article Synopsis
  • The odd-even effect was observed in luminescent Eu complexes with various dicarboxylate ligands for the first time, demonstrating a unique relationship between the molecular structure and luminescent properties.
  • The dehydration temperatures of these complexes exhibited a zigzag pattern based on the carbon chain length of the ligands, showcasing the odd-even effect.
  • The paper introduces the ghost-atom model to explain changes in luminescence intensity parameters and discusses how water molecules impact the luminescence of these complexes.
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Effect of Er,Cr:YSGG laser associated with fluoride on the control of enamel erosion progression.

Arch Oral Biol

March 2019

Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo, SP, 05508-000. Electronic address:

Objective: To evaluate the effect of Er,Cr:YSGG laser associated or not with acidulated phosphate fluoride (APF) on the control of enamel erosion progression.

Design: Enamel slabs (4 mm × 4 mm × 2 mm) from bovine incisors were flattened, polished, and received a tape on their test surfaces, leaving a 4 mm × 1 mm area exposed. Specimens were eroded (10 min in 1% citric acid solution) and randomly assigned into 8 experimental groups (n = 10): Control (no treatment); F (APF gel, 1.

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Purpose: To combine advances in high-speed, wide-field optical coherence tomography angiography (OCTA) with image processing methods for semiautomatic quantitative analysis of capillary nonperfusion in patients with diabetic retinopathy (DR).

Methods: Sixty-eight diabetic patients (73 eyes), either without retinopathy or with different degrees of retinopathy, were prospectively recruited for volumetric swept-source OCTA imaging using 12 mm × 12 mm fields centered at the fovea. A custom, semiautomatic software algorithm was used to quantify areas of capillary nonperfusion.

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Biodegradable polymers containing radioactive isotopes such as Holmium 166 (Ho) have potential applications as beta particle emitters in tumour tissues. It is also a gamma ray emitter, allowing nuclear imaging of any tissue to be acquired. It is frequently used in the form of complexes such as holmium acetylacetonate (HoAcAc), which may cause damages in tissues next to the targets cancer cells, as it is difficult to control its linkage or healthy tissues radiotherapy effects.

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On neutron activation analysis with γγ coincidence spectrometry.

J Radioanal Nucl Chem

October 2017

Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, MS 8395, Gaithersburg, MD 20899-8395, USA.

A new γγ coincidence system has been set up at NIST. It is operated with a digital data finder supported by new software developed at NIST. The system is used to explore possible enhancements in instrumental neutron activation analysis (INAA) and study applicability to neutron capture prompt gamma activation analysis (PGAA).

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Cohabitation with an Ehrlich tumor-bearing cagemate induces immune but not behavioral changes in male mice.

Physiol Behav

February 2017

Neuroimmunomodulation Research Group, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil; Department of Pathology, School of Veterinary Medicine, Universidade de São Paulo, São Paulo, SP, Brazil. Electronic address:

Cohabitation with Ehrlich ascitic tumor-injected conspecifics induces behavioral, neurochemical, endocrine and immune changes indicative of stress and immune impairment in female mice. The present work analyzed the effects of similar cohabitation in Swiss and Balb/C male mice. At least 12 pairs of male mice were divided into a control group and an experimental group.

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