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1.
Materials (Basel) ; 16(6)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36984363

RESUMO

Extrusion-free-form printing of alumina ceramics has the advantages of low cost, short cycle time, and high customization. However, some problems exist, such as the low solid content of ceramic paste and the unsatisfactory mechanical properties of pure alumina ceramics. In this study, SiC nanoparticles were used as a reinforcement phase added to the alumina ceramic matrix. Methylcellulose is used as the binder in the raw material system. Ammonium polyacrylate is used as a dispersant to change the rheological properties of the slurry and increase the solid content of ceramics. SiC nanoparticle-strengthened alumina ceramics were successfully prepared by the extrusion process. The relative settling height and viscosity of ceramic slurries were characterized. The sintering shrinkage of composite ceramics was tested. The flexural strength, fracture toughness, and hardness of the ceramics were characterized. The strengthening and toughening mechanisms of the composite ceramics were further explained by microscopic morphology analysis. Experimental results show that when the content of the dispersant is 1 wt.%, the rheological properties of the slurry are the best. Maximum measured bending strength (227 MPa) and fracture toughness (5.35 MPa·m1/2) were reached by adding 8 wt% SiC nanoparticles; compared with pure alumina ceramics, flexural strength and fracture toughness increased by 42% and 41%, respectively. This study provides a low-cost and effective method for preparing ceramic composite parts.

2.
Materials (Basel) ; 15(19)2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36233987

RESUMO

To investigate the effects of limestone powder and gypsum on the early hydration of ye'elimite, the hydration behavior of C4A3S¯-LP-CaSO4·2H2O-H2O systems are researched. The hydration behavior of systems are researched by employing isothermal calorimetry, XRD technique and chemical shrinkage. The thermodynamic modelling method is employed to predict the equilibrium phase assemblages. The results show that the system with 5 wt.% LP has a comparable hydration heat evolution to limestone powder-free systems. Limestone powder can take part in the reaction to produce monocarboaluminate in the system with M-value (molar ratio of gypsum to ye'elimite) of 1, but monocarboaluminate is not found in the system with M-value of 2. The level off time of chemical shrinkage shortens with the increase of limestone powder dosage. Thermodynamic modelling results show that monocarboaluminate is no longer formed in all systems when M-value exceeds 1.27, which corresponds to the XRD results. This study can provide theoretical guidance for the rational utilization of limestone powder in calcium sulphoaluminate cement.

3.
J Crohns Colitis ; 16(3): 444-451, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-34546360

RESUMO

BACKGROUND AND AIMS: Patient-reported outcomes are recommended endpoints in Crohn's disease [CD] trials. The association between patient-reported general well-being relative to symptoms of diarrhoea and abdominal pain [AP] in patients with moderate to severe CD was explored. METHODS: Patients from three randomized, placebo-controlled, double-blind adalimumab or upadacitinib studies with average daily very soft/liquid stool frequency [SF] ≥4 and/or AP score ≥2 at baseline were included. Using electronic diaries, patients reported general well-being [seven-point Likert scale; 1 = worst; 7 = best] in item 10 of the Inflammatory Bowel Disease Questionnaire [IBDQ]. Changes in well-being and clinical outcomes of SF and AP from baseline to week 12 or 16, and the relationship between well-being and clinical outcomes were evaluated using cumulative distribution function and probability density function curves. RESULTS: In total, 858 patients with CD were included [adalimumab, n = 695; upadacitinib, n = 163]. Patients who achieved clinical remission [SF ≤2.8, AP score ≤1.0, neither worse than baseline] were more likely than those not in clinical remission to report IBDQ item 10 response in the 6-7 group category but not IBDQ categories ≤5. Higher IBDQ score for item 10 [6-7] was associated with lower SF and AP score. Greater point increases in IBDQ item 10 were associated with a greater percentage decrease in clinical parameters; a ≥25-30% decrease in SF or AP was associated with a ≥1-point improvement in IBDQ. CONCLUSIONS: An association between improvements in patient-reported general well-being and clinical remission/response was observed using outcomes of SF and AP, supporting the clinical remission/response endpoint definitions used in clinical studies of CD. Clinical Trial Registrations [ClinicalTrials.gov]: NCT00077779 [CHARM]; NCT00348283 [EXTEND]; NCT02365649 [CELEST].


Assuntos
Doença de Crohn , Dor Abdominal , Adalimumab/uso terapêutico , Doença de Crohn/tratamento farmacológico , Método Duplo-Cego , Humanos , Medidas de Resultados Relatados pelo Paciente
4.
Am J Transl Res ; 13(5): 5066-5072, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34150093

RESUMO

OBJECTIVE: The purpose of this study was to investigate the effects of bracketless invisible orthodontics on the plaque index (PLI), the sulcus bleeding index (SBI), the gingival sulcus probing depth (SPD), and the gingival index (GI) in children with malocclusions and on their families' satisfaction with the orthodontic treatment. METHODS: The baseline data of 113 children with malocclusions were retrospectively collected and divided into two groups according to the orthodontic mode each child underwent. Group A was treated with traditional fixed braces, and Group B was treated with bracketless invisible orthodontics. The clinical efficacy, the satisfaction, the PLI, the SBI, the SPD, and the GI, the tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and the interleukin-2 (IL-2) levels, the occurrence of adverse reactions, the COHIP (oral health-related quality of life scale, Chinese Version), and the changes in oral chewing function were compared between the two groups. RESULTS: The total effective rate in group B was 96.49%, higher than the 69.64% in group A (P<0.05). The total satisfaction rate in group B was 98.25%, higher than the 69.64% in group A (P<0.05). Compared with group A, group B had higher PLI, SBI, SPD, and GI levels after the treatment (P<0.05), lower of TNF-α and IL-6 levels, and higher IL-2 levels (P<0.05). The quality of life and the chewing function scores in group B were higher than they were in group A (P<0.05). The incidence rate of adverse events in group B was 5.26%, lower than the 17.86% in group A (P<0.05). CONCLUSION: The efficacy of bracketless invisible orthodontic treatment in children with malocclusions is higher than it is using traditional fixed orthodontic treatment, as it helps improve their chewing function, periodontal health, and quality of life, and helps reduce the inflammatory factor levels and improves their satisfaction with the orthodontic treatment.

5.
Therap Adv Gastroenterol ; 13: 1756284820938960, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32733600

RESUMO

BACKGROUND AND AIMS: Efficacy of adalimumab in Crohn's disease (CD) has not been shown in China. The aim of this study was to evaluate the efficacy and safety of adalimumab in Chinese patients with CD. METHODS: This 26-week, multicenter, phase III study evaluated patients with moderately to severely active CD and elevated high-sensitivity C-reactive protein (⩾3 mg/l) who were naïve to anti-tumor necrosis factor therapy. Patients were randomized to double-blind adalimumab 160/80 mg at weeks 0/2 and 40 mg at weeks 4/6 or placebo at weeks 0/2 followed by blinded adalimumab 160/80 mg at weeks 4/6. At week 8, all patients received open-label 40 mg adalimumab every other week through week 26. The primary endpoint was clinical remission [CD activity index (CDAI) <150] at week 4. Clinical remission at week 26 was assessed in week-8 responders (decrease in CDAI ⩾70 points at week 8 from baseline) and compared with a clinically meaningful threshold of 30%. Adverse events (AEs) were recorded throughout the study. RESULTS: At baseline, 205 patients were enrolled, with mean [standard deviation (SD)] age of 32.9 (9.9) years and CD duration of 2.7 (3.0) years. At week 4, 38/102 patients (37%) receiving adalimumab and 7/103 (7%) receiving placebo (p < 0.001) achieved clinical remission. Among week-8 responders, 93/144 (65%) achieved clinical remission at week 26 (p < 0.001). No unexpected AEs and no malignancies, active tuberculosis, or deaths were reported. CONCLUSIONS: Adalimumab induced and maintained remission in Chinese patients with CD. Safety results were consistent with the known safety profile of adalimumab. CLINICALTRIALSGOV IDENTIFIER: NCT02499783.

6.
J Occup Environ Med ; 61(6): e253-e259, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30946184

RESUMO

OBJECTIVES: This study aimed to describe a workplace intervention to sensitize employees to sleep problems, and to evaluate the medium-term impact of this intervention on participants' sleep status. METHODS: Employees of different sites (China, France, Spain, and the United Kingdom) of a multinational company were offered a face-to-face session on sleep hygiene with a health professional using a tablet application providing feedback by email. Data on sleep status were collected through an interactive questionnaire at baseline (N = 834 participants) and at 6-month follow-up (n = 291, 34.9% retention). Descriptive statistics, a three-way ANOVA, and a logistic regression model were performed. RESULTS: Sleep quality improved among followed-up participants. Statistically significant results concerned total sleep duration during weekend (P = 0.046), sleep debt (P = 0.019), sleep difficulties (P < 0.001), and sleepiness (P = 0.026). CONCLUSIONS: Interventions blending face-to-face and web-based approaches show promise for effective promotion of sleep awareness at the workplace.


Assuntos
Conscientização , Internet , Sono , Local de Trabalho , Adolescente , Adulto , Feminino , Promoção da Saúde , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Avaliação de Programas e Projetos de Saúde , Inquéritos e Questionários , Adulto Jovem
7.
Nanomaterials (Basel) ; 8(9)2018 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30134583

RESUMO

The influence of graphene oxide (GO) and polyvinyl alcohol (PVA) fiber on the mechanical performance, durability, and microstructure of cement-based materials was investigated in this study. The results revealed that compared with a control sample, the mechanical strength and durability of cement-based materials were significantly improved by adding PVA fiber and GO. The compressive and flexural strength at 28 d were increased by 30.2% and 39.3%, respectively. The chloride migration coefficient at 28 d was reduced from 7.3 × 10-12 m²/s to 4.3 × 10-12 m²/s. Under a sulfate corrosion condition for 135 d, the compressive and flexural strength still showed a 13.9% and 12.3% gain, respectively. Furthermore, from the Mercury Intrusion Porosimetry (MIP) test, with the incorporation of GO, the cumulative porosity decreased from more than 0.13 cm³/g to about 0.03 cm³/g, and the proportion of large capillary pores reduced from around 80% to 30% and that of medium capillary pores increased from approximately 20% to 50%. Scanning electron microscope (SEM) images showed a significant amount of hydration products adhering to the surface of PVA fiber in the GO and PVA fiber modified sample. The addition of GO coupling with PVA fiber in cement-based materials could promote hydration of cement, refine the microstructure, and significantly improve mechanical strength and durability.

8.
Biomed Res Int ; 2017: 4185939, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28194413

RESUMO

Safety is one of the crucial issues for robot-aided neurorehabilitation exercise. When it comes to the passive rehabilitation training for stroke patients, the existing control strategies are usually just based on position control to carry out the training, and the patient is out of the controller. However, to some extent, the patient should be taken as a "cooperator" of the training activity, and the movement speed and range of the training movement should be dynamically regulated according to the internal or external state of the subject, just as what the therapist does in clinical therapy. This research presents a novel motion control strategy for patient-centered robot-aided passive neurorehabilitation exercise from the point of the safety. The safety-motion decision-making mechanism is developed to online observe and assess the physical state of training impaired-limb and motion performances and regulate the training parameters (motion speed and training rage), ensuring the safety of the supplied rehabilitation exercise. Meanwhile, position-based impedance control is employed to realize the trajectory tracking motion with interactive compliance. Functional experiments and clinical experiments are investigated with a healthy adult and four recruited stroke patients, respectively. The two types of experimental results demonstrate that the suggested control strategy not only serves with safety-motion training but also presents rehabilitation efficacy.


Assuntos
Tomada de Decisões , Terapia por Exercício , Medicina de Precisão , Robótica , Segurança , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Terapia por Exercício/instrumentação , Terapia por Exercício/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Medicina de Precisão/instrumentação , Medicina de Precisão/métodos , Robótica/instrumentação , Robótica/métodos , Reabilitação do Acidente Vascular Cerebral/instrumentação , Reabilitação do Acidente Vascular Cerebral/métodos
9.
Colloids Surf B Biointerfaces ; 100: 133-7, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22766289

RESUMO

The direct electrochemistry of hemoglobin (Hb) and application in its interaction with 3,4'-bis-(4-hydro-3-xycoumarin)-2,5-hexanediol (HCH) based on the Hb immobilized in chitosan-room temperature ionic liquid film were investigated by means of cyclic voltammetry, differential pulse voltammetry and amperometry. The binding ratio m and binding constant between HCH and Hb were estimated as 2 and 3.46 M(-1), respectively. The amperometric response showed a linear dependence on the concentration of HCH with the detection limit of 0.06 µM. In addition, the amperometry was a novel method in the field of binding studies and might be taken into account for future binding studies. At last a sensitive and convenient electrochemical method was proposed for the determination of HCH.


Assuntos
Técnicas Biossensoriais , Quitosana/química , Cumarínicos/análise , Glicóis/análise , Inibidores da Protease de HIV/análise , Hemoglobinas/química , Líquidos Iônicos/química , Animais , Bovinos , Técnicas Eletroquímicas , Eletrodos , Humanos , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Proteínas Imobilizadas , Limite de Detecção , Temperatura
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