Sign Language Recognition

This chapter covers the key aspects of sign-language recognition (SLR), starting with a brief introduction to the motivations and requirements, followed by a précis of sign linguistics and their impact on the field. The types of data available and the relative merits are explored allowing examination of the features which can be extracted. Classifying the manual aspects of sign (similar to gestures) is then discussed from a tracking and non-tracking viewpoint before summarising some of the approaches to the non-manual aspects of sign languages. Methods for combining the sign classification results into full SLR are given showing the progression towards speech recognition techniques and the further adaptations required for the sign specific case. Finally the current frontiers are discussed and the recent research presented. This covers the task of continuous sign recognition, the work towards true signer independence, how to effectively combine the different modalities of sign, making use of the current linguistic research and adapting to larger more noisy data set

Development of PMMA-Mon-CNT bone cement with superior mechanical properties and favorable biological properties for use in bone-defect treatment

Treatment of bone defects requires materials or bone cement with superior mechanical properties and favorable biological properties, but this remains unachievable to date. To address this issue, the present study aimed to synthesize and characterize a novel poly(methyl methacrylate) (PMMA) bone cement containing monticellite (Mon) and carbon nanotubes (CNTs) for bone defect treatment. Considerably better mechanical properties were noted in the PMMA-Mon-CNT vs. PMMA and PMMA-Mon bone cements due to the unique resistance of CNTs to crack formation and propagation. Favorable bioactivity was also found in the bone cements containing Mon and CNTs, whereas the PMMA bone cement presented poor bioactivity. Specifically, the incorporation of Mon and CNTs into the PMMA matrix promoted the attachment of MG63 cells compared to the PMMA cement. Thus, the PMMA-Mon-CNT bone cements developed are good potential candidates for filling bone defects in orthopedic surgeries

3D printed microneedles for transdermal drug delivery: A brief review of two decades

Microneedle (MN) technology shows excellent potential in controlled drug delivery, which has got rising attention from investigators and clinics. MNs can pierce through the stratum corneum layer of the skin into the epidermis, evading interaction with nerve fibers. MN patches have been fabricated using various types of materials and application processes. Recently, three-dimensional (3D) printing gives the prototyping and manufacturing methods the flexibility to produce the MN patches in a one-step manner with high levels of shape complexity and duplicability. This review aims to go through the last successes in 3D printed MN-based patches. In this regard, after the evaluation of various types of MNs and fabrication techniques, we will study different 3D printing approaches applied for MN patch fabrication. We further highlight the state of the art of the long-acting MNs and related progress with a specific look at what should come within the scope of upcoming researches

Mechanical property, antibacterial activity and cytocompatibility of a PMMA-based bone cement loaded with clindamycin for orthopaedic surgeries

Local delivery of antibiotics utilising bone cement is a well-known approach for controlling postoperative infections related to implant. 1, 5 and 10 wt.% of clindamycin (Cli) was embedded into polymethylmethacrylate (PMMA)–based bone cement for inhibiting postsurgical infection. Clindamycin antibiotic drug was homogeneously embedded into the matrix of PMMA-based cement. The results revealed that the fabricated PMMA-based cement loaded with Cli presented a high compressive strength (~120 MPa). The PMMA-based cement loaded with low Cli presented better cytocompatibility compared with its counterpart loaded with high Cli owing to the better cell attachment on the surface of the cement with a lower release of Cli. The embedding of Cli into the cement improved its antibacterial performance, as implied by the considerably improved inhibition zone with amplifying Cli concentration. Taken together, PMMA-based cement loaded with 1–5 wt% Cli might be a promising antimicrobial bone cement to be employed in orthopaedic surgeries

Three-dimensional printing constructs based on the chitosan for tissue regeneration: State of the art, developing directions and prospect trends

10.3390/ma13112663Materials1311266

Recent trends in three-dimensional bioinks based on alginate for biomedical applications

10.3390/ma13183980Materials1318398

Three-dimensional printing constructs based on the chitosan for tissue regeneration: State of the art, developing directions and prospect trends

Chitosan (CS) has gained particular attention in biomedical applications due to its biocompatibility, antibacterial feature, and biodegradability. Hence, many studies have focused on the manufacturing of CS films, scaffolds, particulate, and inks via different production methods. Nowadays, with the possibility of the precise adjustment of porosity size and shape, fiber size, suitable interconnectivity of pores, and creation of patient-specific constructs, 3D printing has overcome the limitations of many traditional manufacturing methods. Therefore, the fabrication of 3D printed CS scaffolds can lead to promising advances in tissue engineering and regenerative medicine. A review of additive manufacturing types, CS-based printed constructs, their usages as biomaterials, advantages, and drawbacks can open doors to optimize CS-based constructions for biomedical applications. The latest technological issues and upcoming capabilities of 3D printing with CS-based biopolymers for different applications are also discussed. This review article will act as a roadmap aiming to investigate chitosan as a new feedstock concerning various 3D printing approaches which may be employed in biomedical fields. In fact, the combination of 3D printing and CS-based biopolymers is extremely appealing particularly with regard to certain clinical purposes. Complications of 3D printing coupled with the challenges associated with materials should be recognized to help make this method feasible for wider clinical requirements. This strategy is currently gaining substantial attention in terms of several industrial biomedical products. In this review, the key 3D printing approaches along with revealing historical background are initially presented, and ultimately, the applications of different 3D printing techniques for fabricating chitosan constructs will be discussed. The recognition of essential complications and technical problems related to numerous 3D printing techniques and CS-based biopolymer choices according to clinical requirements is crucial. A comprehensive investigation will be required to encounter those challenges and to completely understand the possibilities of 3D printing in the foreseeable future

Recent trends in three-dimensional bioinks based on alginate for biomedical applications

Three-dimensional (3D) bioprinting is an appealing and revolutionary manufacturing approach for the accurate placement of biologics, such as living cells and extracellular matrix (ECM) components, in the form of a 3D hierarchical structure to fabricate synthetic multicellular tissues. Many synthetic and natural polymers are applied as cell printing bioinks. One of them, alginate (Alg), is an inexpensive biomaterial that is among the most examined hydrogel materials intended for vascular, cartilage, and bone tissue printing. It has also been studied pertaining to the liver, kidney, and skin, due to its excellent cell response and flexible gelation preparation through divalent ions including calcium. Nevertheless, Alg hydrogels possess certain negative aspects, including weak mechanical characteristics, poor printability, poor structural stability, and poor cell attachment, which may restrict its usage along with the 3D printing approach to prepare artificial tissue. In this review paper, we prepare the accessible materials to be able to encourage and boost new Alg-based bioink formulations with superior characteristics for upcoming purposes in drug delivery systems. Moreover, the major outcomes are discussed, and the outstanding concerns regarding this area and the scope for upcoming examination are outlined

CNT and rGO reinforced PMMA based bone cement for fixation of load bearing implants: mechanical property and biological response

Polymethyl methacrylate (PMMA) bone cements (BCs) have some drawbacks, including limited bioactivity and bone formation, as well as inferior mechanical properties, which may result in failure of the BC. To deal with the mentioned issues, novel bioactive polymethyl methacrylate-hardystonite (PMMA-HT) bone cement (BC) reinforced with 0.25 and 0.5 wt% of carbon nanotube (CNT) and reduced graphene oxide (rGO) was synthesized. In this context, the obtained bone cements were evaluated in terms of their mechanical and biological characteristics. The rGO reinforced bone cement exhibited better mechanical properties to the extent that the addition of 0.5 wt% of rGO where its compressive and tensile strength of bioactive PMMA-HT/rGO cement escalated from 92.07 ± 0.72 MPa, and 40.02 ± 0.71 MPa to 187.48 ± 5.79 MPa and 64.92 ± 0.75 MPa, respectively. Besides, the mechanisms of toughening, apatite formation, and cell interaction in CNT and rGO encapsulated PMMA have been studied. Results showed that the existence of CNT and rGO in BCs led to increase of MG63 osteoblast viability, and proliferation. However, rGO reinforced bone cement was more successful in supporting MG63 cell attachment compared to the CNT counterpart due to its wrinkled surface, which made a suitable substrate for cell adhesion. Based on the results, PMMA-HT/rGO can be a proper bone cement for the fixation of load-bearing implants