RESUMO
Over the last few years, fused filament fabrication (FFF) has become one of the most promising and widely used techniques for the rapid prototyping process. A number of studies have also shown the possibility of FFF being used for the fabrication of functional products, such as biomedical implants and automotive components. However, the poor mechanical properties possessed by FFF-processed products are considered one of the major shortcomings of this technique. Over the last decade, many researchers have attempted to improve the mechanical properties of FFF-processed products using several strategies-for instance, by applying the short fiber reinforcement (SFR), continuous fiber reinforcement (CFR), powder addition reinforcement (PAR), vibration-assisted FFF (VA-FFF) methods, as well as annealing. In this paper, the details of all these reinforcement techniques are reviewed. The abilities of each method in improving tensile, flexural, and compressive strength are discussed.
RESUMO
BACKGROUND: At present, few reports are comparing these 2 major cervical posterior laminoplasty methods with Open-door and French-door Laminoplasty in terms of neurological recovery, cervical alignment, and surgical complications. Moreover, most of the research has not been well designed. AIM: This study aims to determine comparative effectiveness and functional outcome of open-door versus french-door laminoplasty for multilevel cervical myelopathy. METHODS: The Meta-analysis is used in this study. The study sample is a published research articles on comparative effectiveness and functional outcome of open-door versus french-door laminoplasty for multilevel cervical myelopathy on the internet through databases on PubMed and ProQuest and published between 1997 until December 2018. Weighted mean difference and pooled weighted mean difference are calculated by using the fixed-effect model or random-effect model. Data is processed by using Review Manager 5.3 (RevMan 5.3). RESULTS: This study reviews 58 articles. There are 6 studies conducted a systematic review and continued with Meta-analysis of relevant data. The results showed significant higher postoperative Japanese Orthopaedic Association (JOA) score in open-door laminoplasty (ODL) than French-door laminoplasty (FDL) (weighted mean difference [WMD] = 0.71; 95% confidence interval [CI]: 0.35 to 1.07; p < 0.05). The outcome of procedures treatment of multilevel cervical myelopathy revealed the operative time, cervical range of motion, axial canal diameter postoperative, axial pain reduction and complications events in ODL and FDL there was no significant difference. But for a cervical lordotic angle in ODL and FDL, there was a significant difference; the ODL group were significantly lesser than the FDL group. The recovery rate in ODL and FDL, there was a significant difference; the ODL was shown to be significantly higher than FDL (p < 0.05). CONCLUSION: This analysis suggests that neither cervical laminoplasty approach is superior, based on the postoperative radiological data and complication rate. But the open-door laminoplasty resulted in a higher functional outcome and recovery rate as compared to the French-door laminoplasty.
RESUMO
The present article reports on the enhancement of the performance and stability of natural dye-based dye-sensitized solar cells (DSSCs). Natural dyes extracted from papaya leaves (PL) were investigated as sensitizers in TiO2-based DSSCs and evaluated in comparison with N719 dye. The acidity of the papaya-leaf extract dyes was tuned by adding benzoic acid. The TiO2 film-coated fluorine-doped tin oxide glass substrates were prepared using the doctor-blade method, followed by sintering at 450 °C. The counter electrode was coated by chemically deposited catalytic platinum. The working electrodes were immersed in N719 dye and papaya dye solutions with concentrations of 8 g/100 mL. The absorbance spectra of the dyes were obtained by ultra-violet-visible spectroscopy. The energy levels of the dyes were measured by the method of cyclic voltammetry. In addition, Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. The DSSC based on the N719 dye displayed a highest efficiency of 0.87% whereas those based on papaya-leaf dye achieved 0.28% at pH 3.5. The observed improved efficiency of the latter was attributed to the increased current density value. Furthermore, the DSSCs based on papaya-leaf dye with pH 3.5-4 exhibited better stability than those based on N719 dye. However, further studies are required to improve the current density and stability of natural dye-based DSSCs, including the investigation of alternative dye extraction routes, such as isolating the pure chlorophyll from papaya leaves and stabilizing it.
