Search Results (8)

The application of metal–organic frameworks (MOFs) has attracted increasing attention in organic synthesis. The modification of MOFs can efficiently tailor the structure and improve the property for meeting ongoing demand in various applications, such as the alteration of gas adsorption and separation, catalytic activity, stability, and sustainability or reusability. In this study, carboxyethylsilanetriol (CEST) disodium salt was used as a dual-functional ligand for modified Al-MIL-53 to fabricate CEST-functionalized Al-MIL-53 samples through a hydrothermal reaction of aluminum nitrate, terephthalic acid, and CEST disodium salt by varying the molar ratio of CEST to terephthalic acid and keeping a constant molar ratio of Al³⁺/-COOH of 1:1. The structure, composition, morphology, pore feature, and stability were characterized by XRD, different spectroscopies, electron microscopy, N₂ physisorption, and thermogravimetric analysis. With increasing CEST content, CEST-Al-MIL-53 still preserves an Al-MIL-53-like structure, but the microstructure changed compared with pure Al-MIL-53 due to the integration of CEST. Such a CEST-Al-MIL-53 was used as the support to load Pd particles and afford a catalyst Pd/CEST-Al-MIL-53 for Suzuki–Miyaura C-C cross-coupling reaction of aryl halides and phenylboronic acid under basic conditions. The resulting Pd/CEST-Al-MIL-53 showed a high catalytic activity compared with Pd/Al-MIL-53, due to the nanofibrous structure of silicon species-integrated CEST-Al-MIL-53. The nanofiber microstructure undergoes a remarkable transformation into intricate 3D cross-networks during catalytic reaction, which enables the leachable Pd particles to orientally redeposit and inlay into these networks as the monodisperse spheres and thereby effectively preventing Pd particles from aggregation and leaching, therefore demonstrating a high catalytic performance, long-term stability, and enhanced reusability. Obviously, the integration of CEST into MOFs can effectively prevent the leaching of active Pd species and ensure the re-deposition during catalysis. Moreover, catalytic performance strongly depended on catalyst dosage, temperature, time, solvent, and the type of the substituted group on benzene ring. This work further extends the catalytic application of hybrid metal–organic frameworks. Full article

Background: Different methods are used for the analysis of marginal and internal fit of partial crowns, but not all of them are applicable for in vivo studies. The aim of this review is to search the available methods, described in the current literature, to assess marginal and internal fit in partial crowns. Methods: an electronic search was performed on Pubmed and Web of Science databases to find studies published from 1 January 2017 up to 2 March 2023, following PRISMA guidelines and Cochrane handbook for systematic reviews. The search strategy applied was: “(marginal) AND (fit OR gap OR adaptation OR discrepancy) AND (inlay OR onlay OR partial crown)”. In vitro studies which evaluated marginal and internal fit on CAD CAM or 3D printed partial crowns were included in this review. Quality of the studies was assessed by using Quality Assessment Tool For In Vitro Studies (QUIN tool). Results: 22 studies were included. Among conventional methods, direct view with microscope, indirect view on resin replicas, and silicone replica technique (SRT) were used. Considering new digital methods, micro-CT, SRT 3D and triple scan technique (TST) were applied. Conclusions: Among 2D methods, direct view technique is the most used marginal fit analysis. For a more comprehensive evaluation, a 3D digital analysis is suggested. SRT and indirect view are the only 2D methods available for in vivo analysis. A protocol for the application of TST for assessment in vivo is now available, but no studies are reported in literature yet. Full article

A number of textile-based fiber optic sensors have recently been proposed for the continuous monitoring of vital signs. However, some of these sensors are likely unsuitable for conducting direct measurements on the torso as they lack elasticity and are inconvenient. This project provides a novel method for creating a force-sensing smart textile by inlaying four silicone-embedded fiber Bragg grating sensors into a knitted undergarment. The applied force was determined within 3 N after transferring the Bragg wavelength. The results show that the sensors embedded in the silicone membranes achieved enhanced sensitivity to force, as well as flexibility and softness. Additionally, by assessing the degree of FBG response to a range of standardized forces, the linearity (R²) between the shift in the Bragg wavelength and force was found to be above 0.95, with an ICC of 0.97, when tested on a soft surface. Furthermore, the real-time data acquisition could facilitate the adjustment and monitoring of force during the fitting processes, such as in bracing treatment for adolescent idiopathic scoliosis patients. Nevertheless, the optimal bracing pressure has not yet been standardized. This proposed method could help orthotists to adjust the tightness of brace straps and the location of padding in a more scientific and straightforward way. The output of this project could be further extended to determine ideal bracing pressure levels. Full article

The aim of this research was to evaluate the mechanical impact of utilizing different fiber-reinforced composite (FRC) systems to reinforce inlay-retained bridges in dissected lower molars with different levels of periodontal support. A total of 24 lower first molars and 24 lower second premolars were included in this study. The distal canal of all molars received endodontic treatment. After root canal treatment, the teeth were dissected, and only the distal halves were kept. Standardized class II occluso-distal (OD) (premolars) and mesio-occlusal (MO) (dissected molars) cavities were prepared in all teeth, and premolar–molar units were created. The units were randomly distributed among four groups (n = six/group). With the aid of a transparent silicone index, direct inlay-retained composite bridges were fabricated. In Groups 1 and 2, both discontinuous (everX Flow) and continuous (everStick C&B) fibers were used for reinforcement, while in Groups 3 and 4, only discontinuous fibers (everX Flow) were used. The restored units were embedded in methacrylate resin, simulating either physiological periodontal conditions or furcation involvement. Subsequently, all units underwent fatigue survival testing in a cyclic loading machine until fracture, or a total of 40,000 cycles. Kaplan–Meyer survival analyses were conducted, followed by pairwise log-rank post hoc comparisons. Fracture patterns were evaluated visually and with scanning electron microscopy. In terms of survival, Group 2 performed significantly better than Groups 3 and 4 (p < 0.05), while there was no significant difference between the other groups. In the case of impaired periodontal support, a combination of both continuous and discontinuous short FRC systems increased the fatigue resistance of direct inlay-retained composite bridges compared to bridges that only contained short fibers. Such a difference was not found in the case of sound periodontal support between the two different bridges. Full article

Spacer fabrics are good for impact force absorption and have the potential for vibration isolation. Inlay knitting of additional material to the spacer fabrics can give reinforcement to the structure. This study aims to investigate the vibration isolation properties of three-layer sandwich fabrics with silicone inlay. The effect of the presence of the inlay, inlay patterns and materials on the fabric geometry, vibration transmissibility and compression behaviour were evaluated. The results showed that the silicone inlay increases the unevenness of the fabric surface. The fabric using polyamide monofilament as the spacer yarn in the middle layer creates more internal resonance than that using polyester monofilament. Silicone hollow tubes inlay increases the magnitude of damping vibration isolation, whereas inlaid silicone foam tubes have the opposite effect. Spacer fabric with silicone hollow tubes inlaid by tuck stitches has not only high compression stiffness but also becomes dynamic, showing several resonance frequencies within the tested frequency range. The findings show the possibility of the silicone inlaid spacer fabric and provide a reference for developing vibration isolation materials with knitted structure and textiles materials. Full article

This in vitro study was designed to investigate whether conventionally produced casts and printed casts for prosthodontic purposes show comparable full-arch accuracy; a ceramic reference cast with inlay and crown preparations was fabricated. Ten gypsum casts were fabricated from conventional silicone elastomeric impressions. Ten digital impressions [IOS] of the reference cast were obtained by an intraoral scanner to fabricate 3D-printed resin casts. The ceramic reference cast, the gypsum, and the printed casts were digitized by an industrial structured light scanner (ILS) and provided as stl files. To evaluate absolute mean trueness values, the digitized gypsum casts [CON], digitized printed casts [PRINT], and [IOS] were superimposed with the digitized ceramic reference cast [REF]. Additionally, each [IOS] scan was compared with its corresponding [PRINT]. The precision was calculated for [CON], [IOS], and [PRINT]. The Mann–Whitney U test for independent samples and the Wilcoxon test for connected samples were performed (p ≤ 0.05). As absolute mean deviation trueness values were obtained: 69 ± 24 µm for [REF]-[CON], 33 ± 4 µm for [REF]-[PRINT], and 19 ± 3 µm for [REF]-[IOS]. The superimposition [IOS]-[PRINT] revealed 38 ± 6 µm. The precision was 74 ± 22 µm for [CON], 32 ± 10 µm for [PRINT], and 15 ± 4 µm for [IOS]. With respect to the workflow, the trueness values of [REF]-[CON] and [REF]-[PRINT] differed significantly. Within the digital workflow, [REF]-[PRINT], [REF]-[IOS], and [IOS]-[PRINT], all values differed significantly. Within the limitations of the study, digital impression and printed cast fabrication were more accurate and reproducible than the conventional workflow. Full article

Insoles provide resistance to ground reaction forces and comfort during walking. In this study, a novel weft-knitted spacer fabric structure with inlays for insoles is proposed which not only absorbs shock and resists pressure, but also allows heat dissipation for enhanced thermal comfort. The results show that the inlay density and spacer yarn increase compression resistance and reduce impact forces. The increased spacer yarn density provides better air permeability but reduces thermal resistance, while a lower inlay density with a random orientation reduces the evaporative resistance. The proposed structure has significantly positive implications for insole applications. Full article

Spacer fabrics are commonly used as cushioning materials. They can be reinforced by using a knitting method to inlay materials into the connective layer which reinforces the structure of the fabric. The compression properties of three samples that were fabricated by inlaying three different types of silicone-based elastic tubes and one sample without inlaid material have been investigated. The mechanical properties of the elastic tubes were evaluated and their relationship to the compression properties of the inlaid spacer fabrics was analysed. The compression behaviour of the spacer fabrics at an initial compressive strain of 10% is not affected by the presence of the inlaid tubes. The Young’s modulus of the inlaid tubes shows a correlation with fabric compression. Amongst the inlaid fabric samples, the spacer fabric inlaid with highly elastic silicone foam tubes can absorb more compression energy, while that inlaid with silicone tubes of higher tensile strength has higher compressive stiffness. Full article