1.Highly Sensitive Poly-N-isopropylacrylamide Microgel-based Electrochemical Biosensor for the Detection of SARS-COV-2 Spike Protein.
Hao CHEN ; Zhi Yuan HOU ; Die CHEN ; Ting LI ; Yi Ming WANG ; Marcelo Andrade DE LIMA ; Ying YANG ; Zhen Zhong GUO
Biomedical and Environmental Sciences 2023;36(3):269-278
OBJECTIVE:
Late 2019 witnessed the outbreak and widespread transmission of coronavirus disease 2019 (COVID-19), a new, highly contagious disease caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Consequently, considerable attention has been paid to the development of new diagnostic tools for the early detection of SARS-CoV-2.
METHODS:
In this study, a new poly-N-isopropylacrylamide microgel-based electrochemical sensor was explored to detect the SARS-CoV-2 spike protein (S protein) in human saliva. The microgel was composed of a copolymer of N-isopropylacrylamide and acrylic acid, and gold nanoparticles were encapsulated within the microgel through facile and economical fabrication. The electrochemical performance of the sensor was evaluated through differential pulse voltammetry.
RESULTS:
Under optimal experimental conditions, the linear range of the sensor was 10 -13-10 -9 mg/mL, whereas the detection limit was 9.55 fg/mL. Furthermore, the S protein was instilled in artificial saliva as the infected human saliva model, and the sensing platform showed satisfactory detection capability.
CONCLUSION
The sensing platform exhibited excellent specificity and sensitivity in detecting spike protein, indicating its potential application for the time-saving and inexpensive detection of SARS-CoV-2.
Humans
;
Microgels
;
Spike Glycoprotein, Coronavirus
;
COVID-19/diagnosis*
;
Gold
;
Metal Nanoparticles
;
SARS-CoV-2
2.Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements
Monte-Filho S. SEVERINO ; Andrade I.E. STEFANI ; Lima B. MARCELO ; Araujo C.U. MARIO
Journal of Pharmaceutical Analysis 2019;9(3):209-216
In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.
3.The influence of nanofillers on the properties of ethanol-solvated and non-solvated dental adhesives
Leonardo Bairrada Tavares DA CRUZ ; Marcelo Tavares OLIVEIRA ; Cintia Helena Coury SARACENI ; Adriano Fonseca LIMA
Restorative Dentistry & Endodontics 2019;44(3):e28-
OBJECTIVES: The aim of this study was to evaluate the influence of different concentrations of nanofillers on the chemical and physical properties of ethanol-solvated and non-solvated dental adhesives. MATERIALS AND METHODS: Eight experimental adhesives were prepared with different nanofiller concentrations (0, 1, 2, and 4 wt%) and 2 solvent concentrations (0% and 10% ethanol). Several properties of the experimental adhesives were evaluated, such as water sorption and solubility (n = 5, 20 seconds light activation), real-time degree of conversion (DC; n = 3, 20 and 40 seconds light activation), and stability of cohesive strength at 6 months (CS; n = 20, 20 seconds light activation) using the microtensile test. A light-emitting diode (Bluephase 20i, Ivoclar Vivadent) with an average light emittance of 1,200 mW/cm2 was used. RESULTS: The presence of solvent reduced the DC after 20 seconds of curing, but increased the final DC, water sorption, and solubility of the adhesives. Storage in water reduced the strength of the adhesives. The addition of 1 wt% and 2 wt% nanofillers increased the polymerization rate of the adhesives. CONCLUSIONS: The presence of nanofillers and ethanol improved the final DC, although the DC of the solvated adhesives at 20 seconds was lower than that of the non-solvated adhesives. The presence of ethanol reduced the strength of the adhesives and increased their water sorption and solubility. However, nanofillers did not affect the water sorption and strength of the tested adhesives.
Adhesives
;
Dental Cements
;
Ethanol
;
Longevity
;
Polymerization
;
Polymers
;
Solubility
;
Solvents
;
Water
4. Antihyperglycemic effect of Passiflora glandulosa cav. fruit rinds flour in streptozotocin-induced diabetic mice
Erlândia Alves Magalhães QUEIROZ ; Raquel Teixeira Terceiro PAIM ; Sandra Machado LIRA ; José Ytalo Gomes DA SILVA ; Carla Laíne Silva LIMA ; Marcelo Oliveira HOLANDA ; Stephen Rathinaraj BENJAMIN ; Maria Izabel Florindo GUEDES ; Ícaro Gusmão Pinto VIEIRA
Asian Pacific Journal of Tropical Medicine 2018;11(9):510-517
Objective: To investigate the effect of administration of Passiflora glandulosa (P. glandulosa) fruit rinds flour on streptozotocin (STZ)-induced diabetic mice. Methods: The preliminary phytochemical screening and parameters such as centesimal composition and brine shrimp toxicity were evaluated. For in vivo study Swiss female mice were divided into four groups: NC-normal control; DC-diabetic control animals receiving saline; MET-diabetic animals receiving metformin (200 mg/kg); PFRF-diabetic animals receiving P. glandulosa fruit rinds flour (200 mg/kg). All of them were treated for 28 d. STZ was used in a single dose of 120 mg/kg to establish diabetic models. Body weight, water and food intake, fasting blood glucose were measured. Histopathological analysis of pancreas and liver were performed to evaluate STZ-induced tissue injuries. Results: Phytochemical screening showed the presence of flavanones and triterpenoids. The P. glandulosa fruit rinds flour was non-toxic by the brine shrimp test. The fruit rinds flour also reduced the loss of body weight and significantly decreased food intake in the diabetic mice. Additionally, a significant reduction in blood glucose was observed for 15 d and this was maintained on 21 d and 28 d when compared with diabetic mice. Furthermore, the P. glandulosa fruit rinds flour has a favourable effect on the histopathological changes of the pancreas in STZ induced diabetes. Conclusions: It is concluded that P. glandulosa fruit rinds flour is a natural product that contains potent antioxidant compounds and presents good prospects for the improvement of diabetic mellitus by reducing serum glucose levels.
5.Is There Any Difference Between Depression and Anxiety in Overactive Bladder According to Sex? A Systematic Review and Meta-Analysis.
Iane Glauce R MELOTTI ; Cássia Raquel Teatin JULIATO ; Suelene Costa de Albuquerque COELHO ; Marcelo LIMA ; Cassio Luiz Zanettini RICCETTO
International Neurourology Journal 2017;21(3):204-211
PURPOSE: Overactive bladder (OAB) is characterized by urinary urgency with or without urge incontinence, accompanied by frequency and nocturia. It affects individuals of all ages and can predispose affected individuals to depression and anxiety. However, few studies have been conducted on this topic. The objective of this study was to perform a systematic review and meta-analysis assessing the symptoms of depression, anxiety, and OAB using validated instruments. METHODS: The search for articles was based on the following descriptors: overactive bladder, depression, and anxiety (“Urinary bladder, Overactive AND Depression and Anxiety”) OR (“Urinary bladder, Overactive AND Depression” OR “Urinary bladder, Overactive AND Anxiety”). The databases searched included PubMed, MEDLINE, and SciELO. RESULTS: Initially, 111 articles were identified, but only 11 articles, containing 11,784 participants with depression and 10,436 with anxiety, specifically addressed depression or anxiety and were included in this systematic review. Ten articles incorporated a quantitative analysis, with cohort, series, population-based, and cross-sectional designs. One qualitative study was also included. Three articles were included in the meta-analysis, resulting in a total of 7,468 participants in whom depression was evaluated and 8,030 participants in whom anxiety was analyzed. Depression and anxiety were positively correlated with OAB. Men with OAB were considerably more likely than women to have anxiety (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.40–1.73) but there was no sex-related difference in depression (OR, 0.96; 95% CI, 0.77–1.21). CONCLUSIONS: This study showed a positive correlation between OAB and anxiety and depression. Men were considerably more likely than women to have anxiety related to OAB, but depression levels in OAB patients were not sex-related. This review highlights the need to investigate depression and anxiety in patients with OAB.
Anxiety*
;
Cohort Studies
;
Depression*
;
Female
;
Humans
;
Male
;
Nocturia
;
Quality of Life
;
Subject Headings
;
Urinary Bladder, Overactive*
;
Urinary Incontinence, Urge
6.Effects of radiant exposure and wavelength spectrum of light-curing units on chemical and physical properties of resin cements.
Adriano Fonseca LIMA ; Stephanie Ellen Ferreira FORMAGGIO ; Lígia França Aires ZAMBELLI ; Alan Rodrigo Muniz PALIALOL ; Giselle Maria MARCHI ; Cintia Helena Coury SARACENI ; Marcelo Tavares DE OLIVEIRA
Restorative Dentistry & Endodontics 2016;41(4):271-277
OBJECTIVES: In this study, we evaluated the influence of different radiant exposures provided by single-peak and polywave light-curing units (LCUs) on the degree of conversion (DC) and the mechanical properties of resin cements. MATERIALS AND METHODS: Six experimental groups were established for each cement (RelyX ARC, 3M ESPE; LuxaCore Dual, Ivoclar Vivadent; Variolink, DMG), according to the different radiant exposures (5, 10, and 20 J/cm²) and two LCUs (single-peak and polywave). The specimens were made (7 mm in length × 2 mm in width × 1 mm in height) using silicone molds. After 24 hours of preparation, DC measurement was performed using Fourier transform infrared spectrometry. The same specimens were used for the evaluation of mechanical properties (flexural strength, FS; elastic modulus, E) by a three-point bending test. Data were assessed for normality, after which two-way analysis of variance (ANOVA) and post hoc Tukey's test were performed. RESULTS: No properties of the Variolink cement were influenced by any of the considered experimental conditions. In the case of the RelyX ARC cement, DC was higher when polywave LCU was used; FS and E were not influenced by the conditions evaluated. The LuxaCore cement showed greater sensitivity to the different protocols. CONCLUSIONS: On the basis of these results, both the spectrum of light emitted and the radiant exposure used could affect the properties of resin cements. However, the influence was material-dependent.
Elastic Modulus
;
Fourier Analysis
;
Fungi
;
Resin Cements*
;
Silicon
;
Silicones
;
Spectrum Analysis
7.Antioxidant therapy enhances pulpal healing in bleached teeth.
Adriano Fonseca LIMA ; Marcelo Rocha MARQUES ; Diana Gabriela SOARES ; Josimeri HEBLING ; Giselle Maria MARCHI ; Carlos Alberto DE SOUZA COSTA
Restorative Dentistry & Endodontics 2016;41(1):44-54
OBJECTIVES: The purpose of this study was to evaluate the histopathological effects of an antioxidant therapy on the pulp tissue of rat teeth exposed to a bleaching gel with 35% hydrogen peroxide. MATERIALS AND METHODS: Forty rats were subjected to oral ingestion by gavage of distilled water (DW) or ascorbic acid (AA) 90 min before the bleaching therapy. For the bleaching treatment, the agent was applied twice for 5 min each to buccal surfaces of the first right mandibular molars. Then, the animals were sacrificed at 6 hr, 24 hr, 3 day, or 7 day post-bleaching, and the teeth were processed for microscopic evaluation of the pulp tissue. RESULTS: At 6 hr, the pulp tissue showed moderate inflammatory reactions in all teeth of both groups. In the DW and AA groups, 100% and 80% of teeth exhibited pulp tissue with significant necrosis and intense tissue disorganization, respectively. At 24 hr, the AA-treated group demonstrated a greater regenerative capability than the DW group, with less intense inflammatory reaction and new odontoblast layer formation in 60% of the teeth. For up to the 7 day period, the areas of pulpal necrosis were replaced by viable connective tissue, and the dentin was underlined by differentiated odontoblast-like cells in most teeth of both groups. CONCLUSIONS: A slight reduction in initial pulpal damage during post-bleaching was promoted by AA therapy. However, the pulp tissue of AA-treated animals featured faster regenerative potential over time.
Animals
;
Ascorbic Acid
;
Connective Tissue
;
Dental Pulp
;
Dentin
;
Eating
;
Hydrogen Peroxide
;
Molar
;
Necrosis
;
Odontoblasts
;
Rats
;
Tooth Bleaching
;
Tooth*
;
Water
8.Antioxidant therapy enhances pulpal healing in bleached teeth.
Adriano Fonseca LIMA ; Marcelo Rocha MARQUES ; Diana Gabriela SOARES ; Josimeri HEBLING ; Giselle Maria MARCHI ; Carlos Alberto DE SOUZA COSTA
Restorative Dentistry & Endodontics 2016;41(1):44-54
OBJECTIVES: The purpose of this study was to evaluate the histopathological effects of an antioxidant therapy on the pulp tissue of rat teeth exposed to a bleaching gel with 35% hydrogen peroxide. MATERIALS AND METHODS: Forty rats were subjected to oral ingestion by gavage of distilled water (DW) or ascorbic acid (AA) 90 min before the bleaching therapy. For the bleaching treatment, the agent was applied twice for 5 min each to buccal surfaces of the first right mandibular molars. Then, the animals were sacrificed at 6 hr, 24 hr, 3 day, or 7 day post-bleaching, and the teeth were processed for microscopic evaluation of the pulp tissue. RESULTS: At 6 hr, the pulp tissue showed moderate inflammatory reactions in all teeth of both groups. In the DW and AA groups, 100% and 80% of teeth exhibited pulp tissue with significant necrosis and intense tissue disorganization, respectively. At 24 hr, the AA-treated group demonstrated a greater regenerative capability than the DW group, with less intense inflammatory reaction and new odontoblast layer formation in 60% of the teeth. For up to the 7 day period, the areas of pulpal necrosis were replaced by viable connective tissue, and the dentin was underlined by differentiated odontoblast-like cells in most teeth of both groups. CONCLUSIONS: A slight reduction in initial pulpal damage during post-bleaching was promoted by AA therapy. However, the pulp tissue of AA-treated animals featured faster regenerative potential over time.
Animals
;
Ascorbic Acid
;
Connective Tissue
;
Dental Pulp
;
Dentin
;
Eating
;
Hydrogen Peroxide
;
Molar
;
Necrosis
;
Odontoblasts
;
Rats
;
Tooth Bleaching
;
Tooth*
;
Water
9.Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa.
Leticia Z OLIVEIRA ; Vera F M HOSSEPIAN DE LIMA ; Marcelo A LEVENHAGEN ; Ricarda M DOS SANTOS ; Terezinha I ASSUMPCAO ; Jose O JACOMINI ; Andre F C DE ANDRADE ; Rubens P DE ARRUDA ; Marcelo E BELETTI
Journal of Veterinary Science 2011;12(3):267-272
The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.
Acrosome/*pathology/ultrastructure
;
Animals
;
Cattle/*physiology
;
Cell Membrane/*pathology/ultrastructure
;
Cell Separation/veterinary
;
Centrifugation, Density Gradient/veterinary
;
Cryopreservation/veterinary
;
Male
;
Microscopy, Electron, Transmission/veterinary
;
Povidone/*adverse effects
;
Silicon Dioxide/*adverse effects
;
Spermatozoa/pathology/ultrastructure

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