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COVID-19 , Pandemias , SARS-CoV-2/genética , Brasil/epidemiologia , COVID-19/epidemiologia , COVID-19/virologia , HumanosRESUMO
Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive malignancy that occurs with unpredictable chemosensitivity and limited treatment options in the advanced setting. Prognosis is poor, and exploring new treatment options for such diseases is difficult because of its rarity. Clinical activity of trabectedin for advanced DSRCT was scarcely reported in the literature. Here, we report a series of six patients treated with trabectedin for an unresectable DSRCT. After receiving trabectedin, two patients had stable disease with a time to progression of 3 and 3.5 months; four patients experienced disease progression after one cycle, two of them could receive one and two patients another line regiment. Four patients experienced grade 3-4 adverse events, two grade 3 thrombocytopenia, and one neutropenic fever. Prognosis was poor with a median overall survival of 4 (range: 2-14) months. In our experience, trabectedin had limited activity in advanced DSRCT. Further studies are warranted to find effective treatments.
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Antineoplásicos Alquilantes/uso terapêutico , Tumor Desmoplásico de Pequenas Células Redondas/tratamento farmacológico , Dioxóis/uso terapêutico , Tetra-Hidroisoquinolinas/uso terapêutico , Adulto , Feminino , Humanos , Infusões Intravenosas , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Pleurais/tratamento farmacológico , Estudos Retrospectivos , Trabectedina , Adulto JovemRESUMO
STATEMENT OF THE PROBLEM: The effect of the intraoral environment during adhesive restorative procedures remains a concern, especially in the absence of rubber dam isolation. OBJECTIVE: To evaluate the temperature and relative humidity (RH) at anterior and posterior intraoral sites and their effects on the dentin bond strength of two-step etch-and-rinse adhesive systems. METHODS: Sixty human molars were assigned to six groups according to the adhesive systems (Adper Single Bond Plus and One Step Plus) and intraoral sites (incisor and molar sites). The room condition was used as a control group. Dentin fragments were individually placed in custom-made acetate trays and direct composite restorations were performed. The intraoral temperature and RH were recorded during adhesive procedures. Then, specimens were removed from the acetate trays and sectioned to obtain multiple beams for the microtensile bond strength test. In addition, the adhesive interface morphology was evaluated through scanning electron microscopy. Intraoral conditions were statistically analyzed by paired Students' t-tests and the bond strength data by two-way analysis of variance and Tukey test (α = 0.05). RESULTS: The posterior intraoral site showed a significant increase in the temperature and RH when compared with the anterior site. However, both intraoral sites revealed higher temperatures and RH than the room condition. In regards to the adhesive systems, the intraoral environment did not affect the bond strength, and the One Step Plus system showed the highest bond strength means. CONCLUSION: Despite the fact that remarkable changes in the intraoral conditions were observed for both anterior and posterior sites, the intraoral environment was not able to compromise the immediate dentin bond strength. CLINICAL SIGNIFICANCE: Some conditions of intraoral temperature and relative humidity may not impair the dentin bond strength of two-step etch-and-rinse adhesive systems. Thus, an adequate relative isolation seems to be a good alternative under the specific clinical conditions in which rubber dam isolation is either impossible or very difficult to perform.
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Colagem Dentária , Dentina/química , Umidade , Teste de Materiais , Temperatura , Resistência à TraçãoRESUMO
Although scientific evidence has shown the effects of tobacco on changes in the color of composite resins, the association between tobacco exposure and the physical properties of composite resins has not been thoroughly investigated. The purpose of this study was to evaluate the effects of cigarette smoke products on water sorption and solubility of microfilled, microhybrid, and nanofilled composite resins (Durafill VS, Filtek Z250, and Filtek Z350 XT, respectively). Ten discs were prepared of each material and divided into 2 groups (n =5), according to cigarette smoke exposure. Specimens were first desiccated until a constant mass was obtained (M1). Then half of the samples were immersed in deionized water while the other half were exposed daily to tobacco smoke, then washed and stored in deionized water. After 21 days, the resin discs were measured (M2) and placed in desiccators until constant mass was achieved (M3). Water sorption and solubility were calculated and the data was statistically analyzed. Water sorption revealed significant differences among the composite resins. The Filtek Z350 XT exhibited the highest water sorption, followed by Durafill VS and Filtek Z250. Cigarette smoke significantly increased water sorption for all products, but only the solubility of Durafill VS showed a significant difference. Filtek Z250 demonstrated significantly lower solubility than Durafill VS, and Filtek Z350 XT had intermediate values. These results indicated that water sorption and solubility varied among the products, and tobacco smoke may alter the physical properties of resin-based materials.
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Resinas Compostas/metabolismo , Fumar/efeitos adversos , Humanos , Solubilidade , ÁguaRESUMO
Management of patients with metastatic melanoma has been revolutionized over the last few years with targeted anti-BRAF therapies for BRAF-mutant melanomas (in about 50% of the cases) and immunotherapy with anti-CTLA-4. Several new drugs are now authorized and available. Because of their new mechanisms of action, they also have new adverse events and guidelines concerning their safety are of critical importance. New innovative strategies using combination of targeted therapies and immunotherapies with anti-PD-1 are in accelerated development. The quality of patient-physician relationship is central to this promising but complex new paradigm of treatment.
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Melanoma/terapia , Neoplasias Cutâneas/terapia , Neoplasias Encefálicas/secundário , Humanos , Metástase Linfática , Melanoma/patologia , Invasividade Neoplásica , Metástase Neoplásica , Estadiamento de Neoplasias , Neoplasias Cutâneas/patologiaRESUMO
[This corrects the article DOI: 10.1016/j.lana.2024.100786.].
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Background: This study focuses on urban arboviruses, specifically dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV), which pose a significant public health challenge in Rio de Janeiro state, Southeast Brazil. In our research, we highlight critical findings on the transmission dynamics of these arboviruses in Rio de Janeiro, identifying distinct patterns of disease spread. Methods: By combining genomic data with case reports from the Brazilian Ministry of Health, we have analysed the phylogenetics, prevalence and spatial distribution of these endemic viruses within the state. Findings: Our results revealed sustained DENV transmission primarily in the northern part of the state, a significant ZIKV epidemic in 2016 affecting all mesoregions, and two major CHIKV outbreaks in 2018 and 2019, predominantly impacting the northern and southern areas. Our analysis suggests an inverse relationship between arboviral case incidence and urban density, with less populous regions experiencing higher transmission rates, potentially attributed to a complex interplay of factors such as the efficacy of vector control measures, environmental conditions, local immunity levels, and human mobility. Furthermore, our investigation unveiled distinct age and gender trends among affected individuals. Notably, dengue cases were predominantly observed in young adults aged 32, while chikungunya cases were more prevalent among individuals over 41. In contrast, cases of ZIKV were concentrated around the 33-year age group. Intriguingly, females accounted for nearly 60% of the cases, suggesting a potential gender-based difference in infection rates. Interpretation: Our findings underscore the complexity of arbovirus transmission and the need for interventions tailored to different geographical mesoregions. Enhanced surveillance and genomic sequencing will be essential for a deeper, more nuanced understanding of regional arbovirus dynamics. Identifying potential blind spots within the state will be pivotal for developing and implementing more effective public health strategies, specifically designed to address the unique challenges posed by these viruses throughout the state. Funding: This study was supported by the National Institutes of Health USA grant U01 AI151698 for the United World Arbovirus Research Network (UWARN) and the CRP-ICGEB RESEARCH GRANT 2020 Project CRP/BRA20-03.
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UNLABELLED: This study evaluated the effects of different parameters of dentin irradiation with erbium -doped yttrium aluminum garnet (Er:YAG) laser on bond strength to dentin and analyzed the ultramorphological characteristics of resin-laser-irradiated dentin interfaces using a transmission electron microscope (TEM). Dentin surfaces were abraded with SiC paper (600 grit) or Er:YAG laser-irradiated (120/4, 140/6, 180/4, or 200/6 mJ/Hz). Three adhesive systems were tested: Single Bond Plus (3M ESPE), Clearfil Protect Bond (Kuraray Med.), and Clearfil Tri-S Bond (Kuraray Med.). Treatments were performed over flat dentin surfaces of human third molars. Specimens were stored in distilled water for 1 week or 6 months and prepared for a microtensile bond strength test and interfacial ultrastructure for analysis. Microtensile bond strength data (n = 5) were analyzed with three-way analysis of variance. Irradiation with Er:YAG laser did not reduce the bond strength values for self-etching adhesives even after 6 months of water storage. The hybrid layer formation was observed only when the adhesives were applied to non-irradiated dentin (control group). Nanoleakage occurred in all resin-dentin interfaces using Single Bond Plus for both periods. Nanoleakage pattern and bond strength of self-etching adhesives to dentin were less affected by Er:YAG laser irradiation and by the 6-month storage in water than was those of the etch-and-rinse adhesive. TEM analysis revealed no hybridization when dentin was laser-irradiated. CLINICAL SIGNIFICANCE: Minimally invasive caries removal has been proposed. Nevertheless, bonding mechanisms to lased dentin are not entirely described. Knowing the interaction between the treated dentin and bonding agents and its behavior over time is of utmost importance for new technologies. Regarding that, two-bottle self-etching adhesive system provided a more consistent evidence of its better behavior when bonding to lased substrate.
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Dentina/efeitos da radiação , Lasers de Estado Sólido/uso terapêutico , Cura Luminosa de Adesivos Dentários/métodos , Cimentos Dentários/uso terapêutico , Corrosão Dentária/métodos , Dentina/ultraestrutura , Humanos , Microscopia Eletrônica de Transmissão , Resinas Sintéticas/uso terapêutico , Propriedades de Superfície , Resistência à Tração , Fatores de TempoRESUMO
PURPOSE: To evaluate the microshear bond strength of resin cements to yttrium-stabilized tetragonal zirconium oxide surfaces after water storage for 24 h or 1 year. MATERIALS AND METHODS: Four self-adhesive (BisCem, G-Cem, RelyX Unicem, SeT) and one conventional resin cement (RelyX ARC) were tested. The materials were mixed and inserted in tubes (0.75 mm diameter × 1 mm height) that were placed over the zirconium oxide surface. Specimens were tested after 24-h or 1-year water storage. Microshear testing was performed using a universal testing machine. Shear bond strength results were analyzed using two-way ANOVA and Tukey's test (5%). RESULTS: After 24-h water storage, no difference was found between G-Cem and RelyX Unicem resin cements; however, their bond strength means to zirconium oxide were statistically higher than RelyX ARC. The bond strength values of all resin cements dropped significantly after 1 year of water storage. G-Cem presented the highest values among cements after long-term water exposure. CONCLUSIONS: One-year water storage decreased the microshear bond strengths to zirconium oxide for all resin cements tested.
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Colagem Dentária , Porcelana Dentária , Cimentos de Resina , Falha de Restauração Dentária , Análise do Estresse Dentário , Armazenamento de Medicamentos , Teste de Materiais , Cimentos de Resina/química , Resistência ao Cisalhamento , Água , Ítrio , ZircônioRESUMO
In recent years dengue has become a rapidly growing public health problem worldwide, however, the availability of accurate and affordable diagnostic immunoassays is limited, partly due to the difficulty of producing large quantities of purified antigen. Non-structural protein 1 (NS1) has shown to be a good candidate for inclusion in diagnostic assays and for serosurveys, particularly in endemic countries as a prerequisite for vaccination. In this work the NS1 antigen derived from dengue virus type-1 (DENV1) was expressed in HEK293-T cells and purified by affinity chromatography. The recombinant protein was recovered properly folded as dimers, highly purified and with good yield (1.5 mg/L). It was applied as a serological probe in an indirect ELISA developed in this work to detect human IgG antibodies. Preliminary comparative performance values of 81.1% sensitivity and 83.0% specificity of the developed and preliminary validated iELISA, relative to a commercial kit were obtained, suggesting that the purified recombinant DENV1 NS1 antigen is suitable to detect IgG antibodies, indicative of past DENV infection.
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Vírus da Dengue , Dengue , Viroses , Animais , Humanos , Vírus da Dengue/genética , Dengue/diagnóstico , Células HEK293 , Sensibilidade e Especificidade , Anticorpos Antivirais , Proteínas não Estruturais Virais , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/metabolismo , MamíferosRESUMO
Gemcitabine has shown clinical activity against angiosarcoma in small series, alone, or combined with taxanes. We aimed to evaluate its activity as a single-agent in a larger series of patients with advanced angiosarcoma. We retrospectively reviewed the electronic medical records of consecutive adult patients with advanced angiosarcoma treated with single-agent gemcitabine at our institutions from January 2010 to January 2021. Response was evaluated according to RECIST 1.1, and toxicity was graded according to NCI-CTC v5.0. 42 patients were identified. 38 patients (90%) had received prior anthracyclines and weekly paclitaxel, and 9 (21%) had received pazopanib. The best tumor response was partial response (PR) in 16 patients (38%), or stable disease (10 patients, 24%). All 8 patients with cardiac angiosarcoma experienced a PR. Median PFS was 5.4 months (95%CI: 3.1-6.5), and median OS was 9.9 months (95%CI: 6.6-13.4). Single-agent gemcitabine has clinically meaningful activity in advanced, heavily pre-treated angiosarcoma.
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Gencitabina , Hemangiossarcoma , Adulto , Humanos , Hemangiossarcoma/etiologia , Estudos Retrospectivos , Desoxicitidina/uso terapêutico , Taxoides/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêuticoRESUMO
Brazil currently ranks second in absolute deaths by COVID-19, even though most of its population has completed the vaccination protocol. With the introduction of Omicron in late 2021, the number of COVID-19 cases soared once again in the country. We investigated in this work how lineages BA.1 and BA.2 entered and spread in the country by sequencing 2173 new SARS-CoV-2 genomes collected between October 2021 and April 2022 and analyzing them in addition to more than 18,000 publicly available sequences with phylodynamic methods. We registered that Omicron was present in Brazil as early as 16 November 2021 and by January 2022 was already more than 99% of samples. More importantly, we detected that Omicron has been mostly imported through the state of São Paulo, which in turn dispersed the lineages to other states and regions of Brazil. This knowledge can be used to implement more efficient non-pharmaceutical interventions against the introduction of new SARS-CoV variants focused on surveillance of airports and ground transportation.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Brasil/epidemiologia , Meios de Transporte , VacinaçãoRESUMO
The aim of this study was to evaluate the effect of light-curing units (LED or halogen) on the marginal adaptation of composite restorations performed with etch-and-rinse and self-etching adhesive. Class V cavities were prepared on bovine teeth with the gingival margin on dentin and the incisal margin on enamel. The cavities were restored with a micro-hybrid resin composite using an etch-and-rinse (Single Bond 2--SB) or a self-etching adhesive (Clearfil SE Bond--CL). The light-activations were performed using halogen lamp (Optilux 501--QTH) or second-generation light-emitting diode (Radii-Cal--LED) (n = 10). After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed under scanning electronic microscopy with 500x of magnification. The greatest gap width at each margin was recorded. Data were submitted to Mann-Whitney and Wilcoxon tests (a = 0.05). SB and CL showed similar behavior of enamel margins when the light-activations were performed with QTH. The same was observed for dentin margins with LED. When the LED was used, higher gap measurements at enamel margins were observed with CL, while higher gap values in dentin were observed for SB within QTH. No significant difference between substrates was found when CL was used. However, SB had significantly higher gap measurements in dentin. The light-curing unit seems to affect the marginal adaptation of resin composite restorations. However this effect was dependent on the adhesive and the location of the margin.
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Resinas Compostas , Lâmpadas de Polimerização Dentária , Cimentos Dentários , Adaptação Marginal Dentária , Restauração Dentária Permanente , Animais , Bovinos , Técnicas In VitroRESUMO
This study evaluated the influence of the prolonged setting time of an ethanol-based adhesive system on the dentin bond strength and degree of conversion. Labial and lingual surfaces of fifteen human third molars were flattened until the dentin was exposed and randomly allocated to 3 groups (n = 10), according to the dwell time between the application of two consecutive layers of the adhesive system (Adper Single Bond Plus, 3M ESPE) and light activation: G1--control (no extra dwell time); G2 and G3--dwell time of 30 seconds and 60 seconds, respectively. After light curing, two cylinders (1.4 x 1 mm) of composite resin (Filtek Flow, 3M ESPE) were bonded to each surface and submitted to micro-shear testing, 24 hours after light curing. A similar adhesive procedure was used for the degree of conversion evaluation using Fourier transform infrared spectroscopy (FTIR). Significant differences between bond strength values (p = 0.0003) and degrees of conversion (p = 0.0004) were detected. The bond strength of G3 (60-second dwell time) was statistically higher than that of other groups. G1 (control) and G2 (30-second dwell time) presented similar results. Values of degree of conversion indicated that both the 30-second and 60-second dwell times resulted in similar and greater percentages of conversion. The use of a longer dwell time (60 seconds) might provide better solvent volatilization and monomer infiltration; bringing benefits to dentin bonding using simplified etch & rinse adhesive systems.
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Colagem Dentária , Adesivos Dentinários , Solventes , Resinas Compostas , Etanol , Humanos , Técnicas In Vitro , Resistência ao Cisalhamento , Fatores de TempoRESUMO
The SARS-CoV-2 responsible for the ongoing COVID pandemic reveals particular evolutionary dynamics and an extensive polymorphism, mainly in Spike gene. Monitoring the S gene mutations is crucial for successful controlling measures and detecting variants that can evade vaccine immunity. Even after the costs reduction resulting from the pandemic, the new generation sequencing methodologies remain unavailable to a large number of scientific groups. Therefore, to support the urgent surveillance of SARS-CoV-2 S gene, this work describes a new feasible protocol for complete nucleotide sequencing of the S gene using the Sanger technique. Such a methodology could be easily adopted by any laboratory with experience in sequencing, adding to effective surveillance of SARS-CoV-2 spreading and evolution.
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Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/epidemiologia , Genes Virais , Pandemias/prevenção & controle , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/genética , Análise de Sequência de RNA/métodos , Glicoproteína da Espícula de Coronavírus/genética , Sequência de Bases , Brasil/epidemiologia , COVID-19/virologia , Testes Diagnósticos de Rotina/métodos , Eletroforese em Gel de Ágar/métodos , Monitoramento Epidemiológico , Humanos , Mutação , RNA Viral/genética , RNA Viral/isolamento & purificaçãoRESUMO
The influenza A virus (IAV) is of a major public health concern as it causes annual epidemics and has the potential to cause pandemics. At present, the neuraminidase inhibitors (NAIs) are the most widely used anti-influenza drugs, but, more recently, the drug baloxavir marboxil (BXM), a polymerase inhibitor, has also been licensed in some countries. Mutations in the viral genes that encode the antiviral targets can lead to treatment resistance. Worldwide, a low prevalence of antiviral resistant strains has been reported. Despite that, this situation can change rapidly, and resistant strain surveillance is a priority. Thus, the aim of this was to evaluate Brazilian IAVs antiviral resistance from 2017 to 2019 through the identification of viral mutations associated with reduced inhibition of the drugs and by testing the susceptibility of IAV isolates to oseltamivir (OST), the most widely used NAI drug in the country. Initially, we analyzed 282 influenza A(H1N1)pdm09 and 455 A(H3N2) genetic sequences available on GISAID. The amino acid substitution (AAS) NA:S247N was detected in one A(H1N1)pdm09 strain. We also identified NA:I222V (n = 6) and NA:N329K (n = 1) in A(H3N2) strains. In addition, we performed a molecular screening for NA:H275Y in 437 A(H1N1)pdm09 samples, by pyrosequencing, which revealed a single virus harboring this mutation. Furthermore, the determination of OST IC50 values for 222 A(H1N1)pdm09 and 83 A(H3N2) isolates revealed that all isolates presented a normal susceptibility profile to the drug. Interestingly, we detected one A(H3N2) virus presenting with PA:E119D AAS. Moreover, the majority of the IAV sequences had the M2:S31N adamantanes resistant marker. In conclusion, we show a low prevalence of Brazilian IAV strains with NAI resistance markers, in accordance with what is reported worldwide, indicating that NAIs still remain an option for the treatment of influenza infections in Brazil. However, surveillance of influenza resistance should be strengthened in the country for improving the representativeness of investigated viruses and the robustness of the analysis.
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Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Antivirais/farmacologia , Antivirais/uso terapêutico , Brasil/epidemiologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Guanidinas/farmacologia , Guanidinas/uso terapêutico , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/metabolismo , Influenza Humana/tratamento farmacológico , Influenza Humana/epidemiologia , Neuraminidase/genética , Neuraminidase/metabolismo , Neuraminidase/uso terapêutico , Oseltamivir/farmacologia , Oseltamivir/uso terapêutico , Prevalência , Estações do AnoRESUMO
In this study, we report the first case of intra-host SARS-CoV-2 recombination during a coinfection by the variants of concern (VOC) AY.33 (Delta) and P.1 (Gamma) supported by sequencing reads harboring a mosaic of lineage-defining mutations. By using next-generation sequencing reads intersecting regions that simultaneously overlap lineage-defining mutations from Gamma and Delta, we were able to identify a total of six recombinant regions across the SARS-CoV-2 genome within a sample. Four of them mapped in the spike gene and two in the nucleocapsid gene. We detected mosaic reads harboring a combination of lineage-defining mutations from each VOC. To our knowledge, this is the first report of intra-host RNA-RNA recombination between two lineages of SARS-CoV-2, which can represent a threat to public health management during the COVID-19 pandemic due to the possibility of the emergence of viruses with recombinant phenotypes.
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COVID-19 , Coinfecção , Humanos , Pandemias , Filogenia , SARS-CoV-2/genéticaRESUMO
During the first semester of 2021, all of Brazil has suffered an intense wave of COVID-19 associated with the Gamma variant. In July, the first cases of Delta variant were detected in the state of Rio de Janeiro. In this work, we have employed phylodynamic methods to analyse more than 1â600 genomic sequences of Delta variant collected until September in Rio de Janeiro to reconstruct how this variant has surpassed Gamma and dispersed throughout the state. After the introduction of Delta, it has initially spread mostly in the homonymous city of Rio de Janeiro, the most populous of the state. In a second stage, dispersal occurred to mid- and long-range cities, which acted as new close-range hubs for spread. We observed that the substitution of Gamma by Delta was possibly caused by its higher viral load, a proxy for transmissibility. This variant turnover prompted a new surge in cases, but with lower lethality than was observed during the peak caused by Gamma. We reason that high vaccination rates in the state of Rio de Janeiro were possibly what prevented a higher number of deaths.
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COVID-19 , SARS-CoV-2 , Brasil/epidemiologia , COVID-19/epidemiologia , Humanos , SARS-CoV-2/genéticaRESUMO
PURPOSE: The erbium laser has been introduced for cutting enamel and dentin and may have an application in the surface modification of high-strength aluminum oxide and zirconia ceramics. The aim of this study was to evaluate the durability of the bond of conventional dual-cured resin cements to Procera Al(2)O(3) and zirconium oxide ceramics after surface treatment with air abrasion and erbium laser. MATERIALS AND METHODS: One hundred twenty Al(2)O(3) and 120 zirconia specimens measuring 3 × 3 × 0.7 mm(3) were divided equally into three groups, and their surfaces treated as follows: either untreated (controls), air abraded with Al(2)O(3) particles, or erbium-laser-treated at a power setting of 200 mJ. The surface of each specimen was then primed and bonded with one of two dual-cured resin cements (either SCP-100 Ceramic Primer and NAC-100 or Monobond S and Variolink II) using a 1-mm thick Tygon tube mold with a 0.75-mm internal bore diameter. After 24 hours and 6 months of water storage at 37°C, a microshear bond strength test was performed at a crosshead speed of 1 mm/min. Surface morphology was examined using a confocal microscope, and failure modes were observed using an optical microscope. The data were analyzed using the Kaplan-Meier nonparametric survival analysis. RESULTS: In the case of zirconia, air abrasion and Erbium:yttrium-aluminum-garnet (Er:YAG) laser treatment of the ceramic surface resulted in a significant reduction in the bond strengths of both resin cements after 6 months water storage; however, when the zirconia surface was left untreated, the SCP-100/NAC-100 group did not significantly reduce in bond strength. In the case of alumina, no treatment, air abrasion and Er:YAG laser treatment of the surface led to no significant reduction in the bond strengths of the three SCP-100/NAC-100 groups after 6 months water storage, whereas all three Monobond S/Variolink II groups showed a significant reduction. CONCLUSION: Er:YAG laser treatment of the zirconia surface did not result in a durable resin cement/ceramic bond; however, a durable bond between a conventional dual-cured resin cement and Procera All Ceram and Procera All Zirkon was formed using a ceramic primer containing the phosphate monomer, MDP, without any additional surface treatment.
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Colagem Dentária , Corrosão Dentária/métodos , Porcelana Dentária , Cimentos de Resina , Abrasão Dental por Ar , Óxido de Alumínio , Análise do Estresse Dentário , Érbio , Estimativa de Kaplan-Meier , Lasers de Estado Sólido , Teste de Materiais , Distribuição Aleatória , Autocura de Resinas Dentárias , Resistência ao Cisalhamento , Propriedades de Superfície , ZircônioRESUMO
This study evaluated the effect of cigarette smoke combined or not with colored beverages on the color change of a composite resin before and after repolishing procedures. Composite specimens were allocated into six groups (N = 10): 1) control (no colorant); 2) cigarette smoke; 3) coffee; 4) coffee and cigarette smoke; 5) red wine; and 6) red wine and cigarette smoke. During 21 days, groups 2, 4, and 6 were exposed daily to the smoke from 20 cigarettes, and groups 3, 4, 5, and 6 were immersed in coffee or red wine for 4 minutes each day. Color measurements were performed with a spectrophotometer at baseline, after 21 days, and after repolishing procedures. Statistical analysis indicated the exposure to cigarette smoke and staining beverages resulted in decreased luminosity (P = .0001) and increased red pigmentation in most experimental groups (P < .05). In groups 3, 4, and 6, an increased yellowish coloration (P = .001) was observed. Irrespective of the experimental group, total color changes were clinically significant (AE > 7.5). Repolishing resulted in greater luminosity, as well as decreased yellow pigmentation (P < .05). It could be concluded that combined staining agents such as cigarette smoke and red wine irreversibly change resin color regardless of the use of repolishing procedures.