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1.
ACS Omega ; 9(9): 10069-10079, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38463283

RESUMO

Single-walled carbon nanotubes (SWCNTs) outperform other materials due to their high conductivity, large specific surface area, and chemical resistance. They have numerous biomedical applications, including the magnetization of the SWCNT (mSWCNT). The drug loading and release properties of see-through pectin hydrogels doped with SWCNTs and mSWCNTs were evaluated in this study. The active molecule in the hydrogel structure is allantoin, and calcium chloride serves as a cross-linker. In addition to mixing, absorption, and swelling techniques, drug loading into carbon nanotubes was also been studied. To characterize the films, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, surface contact angle measurements, and opacity analysis were carried out. Apart from these, a rheological analysis was also carried out to examine the flow properties of the hydrogels. The study was also expanded to include N-(9-fluorenyl methoxycarbonyl)glycine-coated SWCNTs and mSWCNTs as additives to evaluate the efficiency of the drug-loading approach. Although the CNT additive was used at a 1:1000 weight ratio, it had a significant impact on the hydrogel properties. This effect, which was first observed in the thermal properties, was confirmed in rheological analyses by increasing solution viscosity. Additionally, rheological analysis and drug release profiles show that the type of additive causes a change in the matrix structure. According to TGA findings, even though SWCNTs and mSWCNTs were not coated more than 5%, the coating had a significant effect on drug release control. In addition to all findings, cell viability tests revealed that hydrogels with various additives could be used for visual wound monitoring, hyperthermia treatment, and allantoin release in wound treatment applications.

2.
Am J Dent ; 35(6): 284-290, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36508183

RESUMO

PURPOSE: To evaluate and compare in vitro and in vivo color parameters of hybrid ceramic, resin nanoceramic, and artificial acrylic resin teeth. METHODS: For the in vitro stages, 120 specimens (2 mm) were prepared from Vita Enamic (VE), Lava Ultimate (LU), CeraSmart (CS), and acrylic teeth (IV), and immersed in coffee, red wine, and distilled water for 24, 72, and 144 hours. For the in vivo stage, 16 individuals received a complete denture that had upper premolars made of VE, LU, CS blocks, and IV. The color was measured at 1, 3, and 6 months. Color difference (ΔE00), translucency (TP), and contrast ratio (CR) were obtained using a spectrophotometer. Shapiro Wilk, one-way ANOVA, and repeated measures ANOVA were used for statistical analysis. RESULTS: ΔE00 of VE and LU were higher than CS and IV (P< 0.05). ΔTP of VE and LU were lower than CS and IV (P< 0.05). ΔTP of CS was higher in red wine compared to coffee. ΔCR of CS and IV were increased with prolonged immersion (P< 0.001). ΔE00 and ΔCR were similarly affected in coffee and red wine. All discolorations were higher than clinical acceptability (ΔE00> 1.77). For in vivo stages, ΔE00 of VE and LU increased over time (P< 0.01). No difference was detected between in vivo and in vitro ΔE00 of CS (P> 0.05). ΔE00 of VE, LU, and IV was higher in in vitro stages. LU and VE showed lower color stability; their use in esthetic regions is questionable. The prolonged immersion increased discoloration. Coffee and red wine had a similar effect on discoloration and opalescence. Discoloration in laboratory conditions did not correspond to the clinical discoloration according to the new method presented in this study. CLINICAL SIGNIFICANCE: The use of CAD-CAM blocks for endocrowns is rising; however, Lava Ultimate and Vita Enamic showed lower color stability, thus, their use in esthetic regions is questionable. This is the first study that investigates the discoloration of CAD-CAM blocks in clinical use. Discoloration in laboratory conditions did not correspond to the clinical discoloration.


Assuntos
Cerâmica , Desenho Assistido por Computador , Humanos , Teste de Materiais , Propriedades de Superfície , Cor , Dente Artificial
3.
Polymers (Basel) ; 14(6)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35335521

RESUMO

Lightweighting is a challenge for the automotive industry, and foaming is a key technology used to address this problem. A new practical approach is studied to regulate the cell formation of copolymer polypropylene (co-PP) by utilizing graphene nanoplatelets (xGnP) as a process aid during foam injection molding. The approach was designed to enable process freedom to tune part performance by adjusting the amount of xGnP masterbatch. Two different levels of 1-2 wt % xGnP and 0.25-0.35 wt % supercritical fluid (SCF) were investigated. Prepared samples were compared with samples prepared by the traditional method (twin-screw extrusion followed by foam injection molding). The nanocomposite with 2 wt % xGnP comparatively showed about twofold reduction in cell size magnitude. Although the increment in SCF amount resulted in a 47% and 122% enhancement in flexural modulus and strength, respectively, and a 45% loss in Izod unnotched impact strength, the cell size was prone to increasing with regard to low melt strength as compared to neat foams. In conclusion, a 12% weight reduction fulfilled the desired performance parameters in terms of mechanical and sound insulation by utilizing 2 wt % xGnP as a process aid.

4.
Polymers (Basel) ; 14(3)2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35160450

RESUMO

Hypoalbuminemia can lead to poor and delayed wound healing, while it is also associated with acute myocardial infarction, heart failure, malignancies, and COVID-19. In elective surgery, patients with low albumin have high risks of postoperative wound complications. Here, we propose a novel cost-effective wound dressing material based on low-methoxy pectin and NaA-zeolite particles with controlled albumin release properties. We focused on both albumin adsorption and release phenomena for wounds with excess exudate. Firstly, we investigated albumin dynamics and calculated electrostatic surfaces at experimental pH values in water by using molecular dynamics methods. Then, we studied in detail pectin-zeolite hydrogels with both adsorption and diffusion into membrane methods using different pH values and albumin concentrations. To understand if uploaded albumin molecules preserved their secondary conformation in different formulations, we monitored the effect of pH and albumin concentration on the conformational changes in albumin after it was released from the hydrogels by using CD-UV spectroscopy analyses. Our results indicate that at pH 6.4, BSA-containing films preserved the protein's folded structure while the protein was being released to the external buffer solutions. In vitro wound healing assay indicated that albumin-loaded hydrogels showed no toxic effects on the fibroblast cells.

5.
J Invest Surg ; 35(1): 23-29, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32865048

RESUMO

PURPOSE: This study analyzed the safety of myomectomy during the cesarean section (CS). METHODS: Pregnant women who underwent myomectomy during CS in a tertiary center between January 2015 and November 2019 were included in the study in Group A, and pregnant women who did not have myoma and who underwent only CS were included in the study in Group B. The following information was obtained from patient files in hospital archives and was then recorded and compared: age, gravidity, parity, gestational week, characteristics of the myomas (i.e., location, size, number, and type), duration of surgery, perioperative complications, need for blood transfusion, preoperative and postoperative hemoglobin (Hb) values, duration of surgery, and hospital stay duration. RESULTS: A total of 83 patients underwent CS plus myomectomy (Group A), and 80 patients (without myoma) underwent only CS (Group B).There were no statistically significant differences between the groups in terms of preoperative and postoperative Hb values or blood transfusion rates (p > 0.05). Hospitalization and surgery duration were significantly higher in the group that underwent CS myomectomy (p = 0.001 and p = 0.001, respectively). The mean myoma size was 8.3 ± 4.1 cm in Group A. There was a statistically significant and inverse correlation between the size of the myoma and the delivery week (p = 0.035). There was a statistically significant and positive correlation between the myoma size and hospital stay (p = 0.01). CONCLUSION: Myomectomy during CS is safe and can be applied regardless of the location, size, type, and number of myomas. However, to make myomectomy routine during CS, multi-center studies that include more cases are needed.


Assuntos
Cesárea , Miomectomia Uterina , Neoplasias Uterinas , Feminino , Humanos , Tempo de Internação , Período Pós-Operatório , Gravidez , Estudos Retrospectivos , Neoplasias Uterinas/cirurgia
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