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1.
J Biol Inorg Chem ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39009790

RESUMO

Lapachol (2-hydroxy-3-(3-methylbut-2-en-1-yl)naphthalene-1,4-dione) is a 1,4-naphthoquinone-derived natural product that presents numerous bioactivities and was shown to have cytotoxic effects against several human tumor cells. Indium(III) complexes with a variety of ligands also exhibit antineoplastic activity. Indium(III) complexes [In(lap)Cl2].4H2O (1), [In(lap)2Cl(Et3N)] (2), [In(lap)3]·2H2O (3) [In(lap)(bipy)Cl2] bipy = 2,2'-bipyridine (4) and [In(lap)(phen)Cl2] phen = 1,10-phenanthroline (5) were obtained with 2-hydroxy-3-(3-methylbut-2-en-1-yl)naphthalene-1,4-dione (lapachol). Crystal structure determinations for (4) and (5) revealed that the indium(III) center is coordinated to two O atoms from lapachol, two N atoms from 1,10-phenanthroline or 2,2'-bipyridine, and two chloride anions, in a distorted octahedral geometry. Although both complexes (4) and (5) interacted with CT-DNA in vitro by an intercalative mode, only 5 exhibited cytotoxicity against MCF-7 and MDA-MB breast tumor cells. 1,10-phenanthroline and complex (5) presented cytotoxic effects against MCF-7 and MDA-MB cells, with complex (5) being threefold more active than 1,10-phenanthroline on MCF-7 cells. In addition, complex (5) significantly reduced the formation of MDA-MB-231 colonies in a clonogenicity assay. The foregoing results suggest that further studies on the cytotoxic effects and cellular targets of complex (5) are of utmost relevance.

2.
Int J Colorectal Dis ; 39(1): 90, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38866990

RESUMO

INTRODUCTION: Discussions about the optimal lymph node (LN) count and its therapeutic consequences have persisted over time. The final LN count in colorectal tissues is affected by a variety of variables (patient, tumor, operation, pathologist, immune response). Methylene blue (MB) intra-arterial injection is a simple and inexpensive procedure that can be used to enhance lymph node count. AIM: Analyze whether there is a statistically significant difference between intra-arterial methylene blue injection and conventional dissection for the quantification of lymph nodes and determine if there is a variation in the quality of lymph node acquisition. METHODS AND RESULTS: Between 2015 and 2022, we conducted a retrospective analysis of colon cancer specimens. Data on the tumor's features, the number of lymph nodes, the number of lymph nodes that were positive, and other factors had been collected. The number of identified lymph nodes was highly significantly improved in the study group (P < 0.05). There is not a significant statistical difference between groups regarding the metastatic lymph node harvest. The group with injection of intra-arterial methylene blue shows a significantly decreased (P < 0.05) of the of cases with less than 12 lymph nodes recovered comparing with the control group. CONCLUSION: Colon cancer specimens can be easily evaluated concerning lymph nodes using the methylene blue method. Therefore, we strongly advise this approach as a standard procedure in the histological evaluation of colon cancer specimens in order to maximize the identification of lymph nodes. However, the detection of metastatic lymph nodes was unaffected significantly.


Assuntos
Neoplasias do Colo , Azul de Metileno , Humanos , Azul de Metileno/administração & dosagem , Neoplasias do Colo/patologia , Neoplasias do Colo/tratamento farmacológico , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Linfonodos/patologia , Metástase Linfática , Idoso de 80 Anos ou mais , Adulto
3.
Materials (Basel) ; 17(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38930344

RESUMO

Nanocrystalline diamond (NCD) films are attractive for many applications due to their smooth surfaces while holding the properties of diamond. However, their growth rate is generally low using common Ar/CH4 with or without H2 chemistry and strongly dependent on the overall growth conditions using microwave plasma chemical vapor deposition (MPCVD). In this work, incorporating a small amount of N2 and O2 additives into CH4/H2 chemistry offered a much higher growth rate of NCD films, which is promising for some applications. Several novel series of experiments were designed and conducted to tailor the growth features of NCD films by fine-tuning of the gas-phase compositions with different amounts of nitrogen and oxygen addition into CH4/H2 gas mixtures. The influence of growth parameters, such as the absolute amount and their relative ratios of O2 and N2 additives; substrate temperature, which was adjusted by two ways and inferred by simulation; and microwave power on NCD formation, was investigated. Short and long deposition runs were carried out to study surface structural evolution with time under identical growth conditions. The morphology, crystalline and optical quality, orientation, and texture of the NCD samples were characterized and analyzed. A variety of NCD films of high average growth rates ranging from 2.1 µm/h up to 6.7 µm/h were successfully achieved by slightly adjusting the O2/CH4 amounts from 6.25% to 18.75%, while that of N2 was kept constant. The results clearly show that the beneficial use of fine-tuning of gas-phase compositions offers a simple and effective way to tailor the growth characteristics and physical properties of NCD films for optimizing the growth conditions to envisage some specific applications.

4.
Dent Mater ; 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38945742

RESUMO

OBJECTIVES: To assess the effects of different aging protocols on chemical, physical, and mechanical properties of an experimental ATZ composite compared to a zirconia. METHODS: Disc-shaped specimens were obtained through uniaxial pressing of commercial powders (Tosoh), ATZ comprised of 80%ZrO2/20%Al2O3 (TZ-3YS20AB) and 3Y-TZP (3Y-SBE). The specimens of each material were divided into different groups according to the aging protocol: immediate, autoclave aging and hydrothermal reactor aging. The aging protocols were performed at 134 ºC for 20 h at 2.2 bar. Crystalline evaluations were performed using X-Ray Diffraction. The nanoindentation tests measured the elastic modulus (Em) and hardness (H). Biaxial flexural strength was performed, and Weibull statistics were used to determine the characteristic strength and Weibull modulus. The probability of survival was also determined. The Em and H data were analyzed by one-way ANOVA and Tukey test. RESULTS: Diffractograms revealed the presence of monoclinic phase in both materials after aging. The hydrothermal reactor decreased the Em for ATZ compared to its immediate condition; and the H for both ATZ and 3Y-TZP regarding their immediate and autoclave aging conditions, respectively. The aging protocols significantly increased the characteristic strength for ATZ, while decreased for 3Y-TZP. No difference regarding Weibull modulus was observed, except for 3Y-TZP aged in reactor. For missions of up to 500 MPa, both materials presented a high probability of survival (>99 %) irrespective of aging condition. SIGNIFICANCE: The synthesized ATZ composite exhibited greater physical and microstructural stability compared to 3Y-TZP, supporting potential application of the experimental material for long-span reconstructive applications.

5.
An Acad Bras Cienc ; 96(1): e20230539, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38597500

RESUMO

Green manure (GM) may reduce the use of chemical fertilizers, been an ecologically appropriate strategy to cultivation of medicinal plants. Crotalaria juncea, is one of the most used because it adapts to different climatic and high nitrogen content. Origanum vulgare. is widely used in cooking, pharmaceutical, cosmetic industries and food products. The objectives of this study were to evaluate the GM on biomass, essential oil (EO), phenolic and antioxidant. The experiment consisted: control; 150, 300, 450, and 600 g (Sh= leaves+steam) more 200 g roots (R); 600 g aerial part; 200 g roots; and soil with 300 g cattle manure per pot. The highest dry weights were observed in the presence of GM and cattle manure (90 days). The control had an EO production 75% lower in relation to the dose of 450 g GM (Sh+R). Principal component analysis showed that GM and cattle manure positively influenced the dry weight, content, yield, and EO constituents, and total flavonoids. The GM contributed to the accumulation of the major EO compounds (trans-sabinene hydrate, thymol, terpinen-4-ol). The GM management may be beneficial for cultivating, because it can increase the production of biomass and the active components, in addition to being an inexpensive resource.


Assuntos
Crotalaria , Óleos Voláteis , Origanum , Bovinos , Animais , Óleos Voláteis/química , Origanum/química , Esterco , Biomassa , Compostos Fitoquímicos
6.
Talanta ; 272: 125787, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38401267

RESUMO

Multi-signal calibrations have been recently exploited in molecular spectrochemical analysis alternatively to traditional calibration methods, improving analytical frequency and accuracy. The application of these strategies is simple and minimizes efficiently matrix effects by analyzing two calibration solutions comprising sample plus standard (S1), and sample plus blank (S2). The plot of the signals obtained with S1 and S2 at multiple settings (e.g. different wavelengths) yield a slope that can be related to the analyte concentration in the sample. Similarly, transient signals could also be related to the analyte concentration exploiting a similar strategy. Thus, in this work, two multi-signal approaches developed in flow-based systems are proposed, based on the responses at multiple wavelengths (online multi-energy calibration, OMEC), and on the dispersion profile of the samples, herein denominated multi-dispersion calibration (MDC). The calibrations were carried out with sample solutions after 2-fold dilution with a standard solution and with water. The feasibility of OMEC and MDC were demonstrated using KMnO4 solutions (without chemical reactions) under continuous and pulsed flow regimes. The applicability of this strategy was also demonstrated by the spectrophotometric determination of urea in milk and pet potty spray in a multi-pumping flow system, based on the color change of bromothymol blue after catalyzed hydrolysis by urease from jack beans (Canavalia ensiformis). MDC and OMEC were compared with external calibrations (EC) and classical standard addition. The limits of detection for urea were estimated at 13 mg L-1, 16 mg L-1, and 10 mg L-1 using MDC, MEC and EC, respectively. Recoveries from 93 to 101%, and the agreement of sample analyzes with the reference procedure demonstrated the good accuracy achieved by the proposed methods. Therefore, it was demonstrated the feasibility of MDC and OMEC for analytical purposes in a simple and efficient way with the advantages of flow-based manifolds.

7.
Surg Oncol ; 53: 102046, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38377643

RESUMO

PURPOSE: In patients with colorectal cancer (CRC), the most important factor to decide the need of adjuvant chemotherapy is the histological lymph node (LN) evaluation. Our work aimed to give a broad view over the use of methylene blue and its consequences in the number of lymph node harvest. METHODS: PUBMED, WEB OF SCIENCE and EMBASE databases were consulted, retrieving clinical trials, which mentioned the used of intra-arterial methylene blue in patients with colorectal cancer. RESULTS: Eighteen clinical trials analyzing the use of intra-arterial methylene blue in specimens of colorectal cancer were selected. The articles show a statistical difference between the use of methylene blue and the classical dissection in both variable at study. The results of the statistical analysis of the lymph node harvest variable demonstrate a significant statistical difference between the group that received methylene blue injection and the group that underwent conventional dissection. There is a significant statistical difference between the experimental and control groups for the ideal lymph node harvest (lymph node harvest count greater than 12). CONCLUSION: The use of intra-arterial methylene blue revealed a high potential for the quantification of lymph nodes, considering the increase of lymph node harvest and the higher percentage of cases with more than 12 lymph nodes count, albeit the high heterogeneity between the studies in terms of reported results. Future investigations with controlled double blinded studies obtaining better categorized results should be conducted in order to better evaluate this technique and compare it to the current paradigm.


Assuntos
Neoplasias Colorretais , Excisão de Linfonodo , Humanos , Excisão de Linfonodo/métodos , Azul de Metileno/uso terapêutico , Linfonodos/patologia , Dissecação , Neoplasias Colorretais/patologia , Biópsia de Linfonodo Sentinela
8.
J Phys Condens Matter ; 36(14)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38157558

RESUMO

TbxPr1-xAl2are ferrimagnetic materials exhibiting magnetocaloric effect that have gained considerable attention due to their potential use as an alternative in refrigeration, magnetic sensors and in information storage technology. Here using the mean field approach numerical simulations were conducted forx= 0.1, 0.2, 0.3, 0.4, 0.5, and 0.75, to analyze selected physical properties, such as x-ray and neutron powder diffraction, magnetization and heat capacity. The simulations successfully reproduced the experimental data providing a comprehensive characterization and improved understanding of this family of compound.

9.
Int J Mol Sci ; 24(22)2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38003733

RESUMO

Due to their characteristics, mesenchymal stem cells (MSCs) are considered a potential therapy for brain tissue injury or degeneration. Nevertheless, despite the promising results observed, there has been a growing interest in the use of cell-free therapies in regenerative medicine, such as the use of stem cell secretome. This review provides an in-depth compilation of data regarding the secretome composition, protocols used for its preparation, as well as existing information on the impact of secretome administration on various brain conditions, pointing out gaps and highlighting relevant findings. Moreover, due to the ability of MSCs to respond differently depending on their microenvironment, preconditioning of MSCs has been used to modulate their composition and, consequently, their therapeutic potential. The different strategies used to modulate the MSC secretome were also reviewed. Although secretome administration was effective in improving functional impairments, regeneration, neuroprotection, and reducing inflammation in brain tissue, a high variability in secretome preparation and administration was identified, compromising the transposition of preclinical data to clinical studies. Indeed, there are no reports of the use of secretome in clinical trials. Despite the existing limitations and lack of clinical data, secretome administration is a potential tool for the treatment of various diseases that impact the CNS.


Assuntos
Lesões Encefálicas , Células-Tronco Mesenquimais , Humanos , Secretoma , Medicina Regenerativa/métodos , Terapia Baseada em Transplante de Células e Tecidos
10.
J Antimicrob Chemother ; 78(Suppl 2): ii25-ii36, 2023 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-37995357

RESUMO

The emergence and worldwide spread of SARS-CoV-2 during the COVID-19 pandemic necessitated the adaptation and rapid deployment of viral WGS and analysis techniques that had been previously applied on a more limited basis to other viral pathogens, such as HIV and influenza viruses. The need for WGS was driven in part by the low mutation rate of SARS-CoV-2, which necessitated measuring variation along the entire genome sequence to effectively differentiate lineages and characterize viral evolution. Several WGS approaches designed to maximize throughput and accuracy were quickly adopted by surveillance labs around the world. These broad-based SARS-CoV-2 genomic sequencing efforts revealed ongoing evolution of the virus, highlighted by the successive emergence of new viral variants throughout the course of the pandemic. These genomic insights were instrumental in characterizing the effects of viral mutations on transmissibility, immune escape and viral tropism, which in turn helped guide public health policy, the use of monoclonal antibody therapeutics and vaccine development strategies. As the use of direct-acting antivirals for the treatment of COVID-19 became more widespread, the potential for emergence of antiviral resistance has driven ongoing efforts to delineate resistance mutations and to monitor global sequence databases for their emergence. Given the critical role of viral genomics in the international effort to combat the COVID-19 pandemic, coordinated efforts should be made to expand global genomic surveillance capacity and infrastructure towards the anticipation and prevention of future pandemics.


Assuntos
COVID-19 , Hepatite C Crônica , Humanos , SARS-CoV-2/genética , Antivirais , Pandemias , Genômica
11.
PLoS One ; 18(10): e0292216, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37796786

RESUMO

OBJECTIVE: ChatGPT is the first large language model (LLM) to reach a large, mainstream audience. Its rapid adoption and exploration by the population at large has sparked a wide range of discussions regarding its acceptable and optimal integration in different areas. In a hybrid (virtual and in-person) panel discussion event, we examined various perspectives regarding the use of ChatGPT in education, research, and healthcare. MATERIALS AND METHODS: We surveyed in-person and online attendees using an audience interaction platform (Slido). We quantitatively analyzed received responses on questions about the use of ChatGPT in various contexts. We compared pairwise categorical groups with a Fisher's Exact. Furthermore, we used qualitative methods to analyze and code discussions. RESULTS: We received 420 responses from an estimated 844 participants (response rate 49.7%). Only 40% of the audience had tried ChatGPT. More trainees had tried ChatGPT compared with faculty. Those who had used ChatGPT were more interested in using it in a wider range of contexts going forwards. Of the three discussed contexts, the greatest uncertainty was shown about using ChatGPT in education. Pros and cons were raised during discussion for the use of this technology in education, research, and healthcare. DISCUSSION: There was a range of perspectives around the uses of ChatGPT in education, research, and healthcare, with still much uncertainty around its acceptability and optimal uses. There were different perspectives from respondents of different roles (trainee vs faculty vs staff). More discussion is needed to explore perceptions around the use of LLMs such as ChatGPT in vital sectors such as education, healthcare and research. Given involved risks and unforeseen challenges, taking a thoughtful and measured approach in adoption would reduce the likelihood of harm.


Assuntos
Docentes , Inclusão Escolar , Humanos , Escolaridade , Instalações de Saúde , Probabilidade
12.
J Prosthet Dent ; 130(5): 739.e1-739.e8, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37684141

RESUMO

STATEMENT OF PROBLEM: The bonding of implant-supported prostheses is determined by abutment material, convergence angle, height, surface treatment, and luting agents. However, studies evaluating the bonding of luting agents to titanium base abutments with different heights under fatigue conditions are scarce. PURPOSE: The purpose of this in vitro study was to evaluate the retention of zirconia crowns bonded with different luting agents to titanium base abutments of different heights before and after fatigue testing. MATERIAL AND METHODS: Zirconia crowns were designed, milled, and distributed into 4 experimental groups according to the luting agents (G-Multi Primer/G-Cem LinkForce [MP/GC] and Scotchbond Universal/RelyX Ultimate [SU/RU]) and titanium base abutment heights (2.5 mm and 4 mm) (n=10). Pull-out testing was performed in a universal testing machine at a crosshead speed of 1 mm/min until crown displacement. Fatigue testing was performed by an electric precision fatigue simulator (1×106 cycles; 100 N; and 15 Hz), followed by pull-out testing of fatigued specimens. Collected data were statistically evaluated by using a linear mixed model after post hoc comparisons by the least significant difference test (α=.05). RESULTS: Luting agents, abutment heights, and fatigue influenced the bonding retention of zirconia crowns to titanium base abutments. SU/RU agents promoted higher pull-out compared with MP/GC for both abutment heights before and after fatigue. Higher abutment height increased pull-out regarding lower abutment height for SU/RU materials before and after fatigue testing. Although fatigue had no significant effect on the pull-out of MP/GC, lower bond retention was observed for SU/RU after fatigue, regardless of abutment height. CONCLUSIONS: Luting agent composition and the interaction with abutment height and fatigue influenced the retention of zirconia crowns to titanium base abutments.


Assuntos
Cimentos Dentários , Implantes Dentários , Cimentos Dentários/química , Titânio/química , Coroas , Zircônio/química , Teste de Materiais , Dente Suporte , Análise do Estresse Dentário
13.
Chem Biodivers ; 20(10): e202300809, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37702456

RESUMO

The objective of this study was to evaluate the effect of ChromatiNet on vegetative growth, total antioxidant capacity, phenolic and essential oils (EOs) composition of Lippia gracilis. The plants were cultivated under full sunlight, black, blue and red ChromatiNet. The flavonoid content and antioxidant capacity were quantified spectrophotometrically. The C-glycosylflavone isomers (orientin and isoorientin) were isolated and identified by conventional spectroscopic techniques and measured using high-performance liquid chromatography-diode array detection. The EO was analysed by gas chromatography and gas chromatography-mass spectrometry. Environment influenced growth, total antioxidant capacity and phytochemical levels. Shoot dry weight, thymol, carvacrol and (E)-caryophyllene were favoured under red and black ChromatiNet. Root growth, EOs, caryophyllene oxide, p-cymene, flavonoids, orientin and isoorientin were favoured in sunlight. Growth and accumulation of EOs, flavonoids and photosynthetic pigments increased under blue ChromatiNet. Therefore, Lippia gracilis plants have plasticity related to the spectral quality of light and it cultivate depends of the phytochemicals of interest.

14.
Rev Col Bras Cir ; 50: e20233435, 2023.
Artigo em Inglês, Português | MEDLINE | ID: mdl-37531500

RESUMO

OBJECTIVES: the purpose of this study was to evaluate the outcome of rectal cancer surgery, in a unit adopting the principles of total mesorectal excision (TME) with a high restorative procedure rate and with a low rate of abdominoperineal excision (APE). METHODS: we enrolles patients with extraperitoneal rectal cancer undergoing TME or TME+APE. Patients with mid rectal tumors underwent TME, and patients with tumors of the lower rectum and no criteria for APE underwent TME and intersphincteric resection. Those in which the intersphincteric space was invaded and in those with a free distal margin less than 1cm or a tumor free radial margin were unattainable underwent APE or extralevator abdominoperineal excision (ELAPE). We assessed local recurrence rates, overall survival and involvement of the radial margin. RESULTS: sixty (89.6%) patients underwent TME and seven (10.4%) TME + APE, of which five underwent ELAPE. The local recurrence, in pacientes undergoing TME+LAR, was 3.3% and in patients undergoing APE, 14.3%. The local recurrence rate (p=0.286) or the distant recurrence rate (p=1.000) was similar between groups. There was no involvement of radial margins. Survival after 120 months was similar (p=0.239). CONCLUSION: rectal malignancies, including those located in the low rectum, may be surgically treated with a low rate of APE without compromising oncological principles and with a low local recurrence rates.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Hominidae , Protectomia , Neoplasias Retais , Humanos , Animais , Reto/cirurgia , Estudos Prospectivos , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Neoplasias Retais/cirurgia , Neoplasias Retais/patologia , Períneo/cirurgia , Períneo/patologia , Resultado do Tratamento , Recidiva Local de Neoplasia/epidemiologia
15.
J Indian Soc Periodontol ; 27(4): 392-398, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37593548

RESUMO

Background: To analyze through finite element analysis the stress distribution in peri-implant bone tissues, implants, and prosthetic components induced by the socket shield (SS) technique in comparison to other techniques used to treat tooth loss. Materials and Methods: A three-dimensional model of a superior central incisor crown supported by implant was modeled and three different placement conditions were simulated: SS - 2.0-mm-thick root dentin fragment positioned between the alveolar buccal wall and implant; heterologous bone graft (HBG) - bovine bone graft positioned the alveolar buccal wall and implant; and control (C) - implant fully placed in bone tissue of a healed alveolus. The model was restricted at the lateral surfaces of the bone tissue and the following loads were simulated: Both oblique (45°) loads of 100 N on the lingual surface of the crown (maximal habitual intercuspation) and 25.5 N on the incisal edge of the crown (tooth contact during mandibular protrusion) were simultaneously applied. Tensile stress, shear stress, compression, and displacement were analyzed in the cortical bone, trabecular bone, dentin root fragment, and bone graft; while equivalent von Mises stresses were quantified in the implant and prosthetic components. Results: Stress values of SS and HBG in the bone tissues were higher than C, while slight differences within models were observed for dentin root fragment, bone graft, implant, and prosthetic components. Conclusions: The SS technique presented the highest stress concentration in the peri-implant tissues.

16.
Sci Adv ; 9(31): eadg2122, 2023 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-37540749

RESUMO

Since the initial spread of severe acute respiratory syndrome coronavirus 2 infection, several viral variants have emerged and represent a major challenge for immune control, particularly in the context of vaccination. We evaluated the quantity, quality, and persistence of immunoglobulin G (IgG) and IgA in individuals who received two or three doses of messenger RNA (mRNA) vaccines, compared with previously infected vaccinated individuals. We show that three doses of mRNA vaccine were required to match the humoral responses of preinfected vaccinees. Given the importance of antibody-dependent cell-mediated immunity against viral infections, we also measured the capacity of IgG to recognize spike variants expressed on the cell surface and found that cross-reactivity was also strongly improved by repeated vaccination. Last, we report low levels of CXCL13, a surrogate marker of germinal center activation and formation, in vaccinees both after two and three doses compared with preinfected individuals, providing a potential explanation for the short duration and low quality of Ig induced.


Assuntos
COVID-19 , Humanos , COVID-19/prevenção & controle , Anticorpos Antivirais , Vacinação , Imunoglobulina G , RNA Mensageiro , Quimiocina CXCL13/genética
17.
Anal Methods ; 15(24): 2997-3004, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37310407

RESUMO

Biodiesel is an important alternative fuel produced from animal fats or vegetable oils. According to several world regulatory agencies, the acceptable threshold content for free glycerol in biodiesel is 200 mg kg-1. Exceeding concentrations may yield high amounts of acrolein after combustion. The analytical methods for glycerol determination are usually preceded by conventional liquid-liquid extraction that may affect precision and accuracy and impair analytical frequency. In this work, a multi-pumping flow system was proposed for the online dispersive liquid-liquid extraction of free glycerol from biodiesel followed by spectrophotometric determination. The analyte was transferred to the aqueous phase by mixing the sample and water under a pulsed flow regime. The emulsion was directed towards a retention column to remove the organic phase before chemical derivatization. Glycerol was oxidized by NaIO4 to generate formaldehyde, which reacted with acetylacetone in an ammonium acetate medium to yield 3,5-diacetyl-1,4-dihydrolutidine (λMAX = 412 nm). The optimization of the main parameters of the system was carried out by multivariate methods. The screening of variables was performed by fractional factorial design 24-1. The models for free glycerol determination and extraction were refined by central composite and full factorial 23, respectively. In both cases, the validation was carried out by analysis of variance, which yielded a satisfactory F-test value. After optimization, a linear range from 3.0 to 50.0 mg L-1 glycerol was observed. The detection limit, coefficient of variation and determination frequency were estimated to be 2.0 mg L-1 (n = 20; 99.7% confidence level), 4.2-6.0% (n = 20) and 16 h-1, respectively. The efficiency of the process was estimated to be 66%. After each extraction, the retention column (filled with 185 mg of glass microfiber) was washed with 50% ethanol solution to avoid carry-over effects. The comparative analyses of samples by the proposed and reference methods demonstrated the accuracy of the developed procedure at a 95% confidence level. Recoveries between 86 and 101% also indicated that the proposed procedure is accurate, suitable and reliable for online extraction and determination of free glycerol in biodiesel.


Assuntos
Glicerol , Microextração em Fase Líquida , Animais , Glicerol/análise , Microextração em Fase Líquida/métodos , Biocombustíveis/análise , Água/química , Extração Líquido-Líquido
18.
Braz Oral Res ; 37: e43, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37132730

RESUMO

The present study evaluated the effect of the taper angle of different internal conical connection implants and cyclic loading on the implant-abutment bacterial seal. A total of 96 implant-abutment sets were divided into eight groups. Four groups of different taper degrees with cyclic mechanical loading of 500,000 cycles per sample, with a 120-N load at 2 Hz before analysis [16DC (16-degree, cycled), 11.5DC (11.5-degree, cycled), 3DC (3- degree, cycled) and 4DC (4- degree, cycled)] were compared to four control groups without cyclic loading [16D (16-degree), 11.5D (11.5-degree), 3D (3-degree), and 4D (4-degree)]. Microbiological analysis was performed by immersing all samples in a suspension containing Escherichia coli and incubating them at 37°C. After 14 days, the presence of bacterial seals was evaluated. Fisher-Freeman-Halton exact tests and binomial tests were performed (5% significance level). The groups showed significant differences in bacterial seal, and mechanical load cycling improved the bacterial seal in the 3DC group. In all other groups, no significant differences in bacterial seal were found between cycled and uncycled samples. To conclude, the internal conical connection with a 3-degree taper angle showed better results than the other connection with different angles when subjected to load cycling. However, none of the angles tested were fully effective in sealing the implant-abutment interface.


Assuntos
Implantes Dentários , Implantes Dentários/microbiologia , Dente Suporte , Projeto do Implante Dentário-Pivô
19.
medRxiv ; 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37066228

RESUMO

Objective ChatGPT is the first large language model (LLM) to reach a large, mainstream audience. Its rapid adoption and exploration by the population at large has sparked a wide range of discussions regarding its acceptable and optimal integration in different areas. In a hybrid (virtual and in-person) panel discussion event, we examined various perspectives regarding the use of ChatGPT in education, research, and healthcare. Materials and Methods We surveyed in-person and online attendees using an audience interaction platform (Slido). We quantitatively analyzed received responses on questions about the use of ChatGPT in various contexts. We compared pairwise categorical groups with Fisher's Exact. Furthermore, we used qualitative methods to analyze and code discussions. Results We received 420 responses from an estimated 844 participants (response rate 49.7%). Only 40% of the audience had tried ChatGPT. More trainees had tried ChatGPT compared with faculty. Those who had used ChatGPT were more interested in using it in a wider range of contexts going forwards. Of the three discussed contexts, the greatest uncertainty was shown about using ChatGPT in education. Pros and cons were raised during discussion for the use of this technology in education, research, and healthcare. Discussion There was a range of perspectives around the uses of ChatGPT in education, research, and healthcare, with still much uncertainty around its acceptability and optimal uses. There were different perspectives from respondents of different roles (trainee vs faculty vs staff). More discussion is needed to explore perceptions around the use of LLMs such as ChatGPT in vital sectors such as education, healthcare and research. Given involved risks and unforeseen challenges, taking a thoughtful and measured approach in adoption would reduce the likelihood of harm.

20.
Polymers (Basel) ; 15(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37050293

RESUMO

This study evaluated the apical sealing ability and bioactivity of an experimental gutta-percha containing niobium phosphate bioglass. Thirty-six human premolars were endodontically prepared and divided into three groups: GPC-filling with conventional gutta-percha; GBC-filling with bioceramic gutta-percha (EndoSequence BC); GNB-filling with experimental gutta-percha containing niobophosphate. Teeth were stored in tubes containing 2 mL of simulated body fluid (SBF) solution in an oven for 30 days. Then, the samples were immersed in lanthanum nitrate solution and analyzed for apical nanoleakage (NI) with a scanning electron microscope (SEM/EDS) and transmission electron microscope (TEM). Gutta-percha specimens were immersed for 28 days (SBF) and analyzed in SEM/EDS and X-ray diffraction (XRD) to assess bioactivity. NI data originated from the SEM/EDS were analyzed using the Kruskal-Wallis test (α = 5%). NI data originated from TEM and bioactivity were descriptively reported. Statistical analysis did not detect a significant difference between groups (p = 0.13) for NI. In the bioactivity analysis, an abundant layer of hydroxyapatite was identified only in the surface of the GNB group samples. The gutta-percha containing niobophosphate bioglass promoted an apical sealing similar to EndoSequence BC, in addition to demonstrating bioactivity through the deposition of hydroxyapatite on the surface of the material after immersion in SBF.

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