The fabrication of titanium alloy biomedical implants using additive manufacturing: a way forward

A biomedical implant is a man-made transplanted device used to replace missing life structures and support damaged biological hard tissue. The primary goal of these structures is to preserve the anatomical fixation of the human body. Currently, advanced titanium alloys occupy almost half of the market share of implant products however, they still pose concerns such as decreasing osteogenesis during application. This paper presents a review of the role of additive manufacturing (AM) in providing innovative methods for fabricating metallic alloys toward Industrial Revolution 4.0. Initially, an overview of biomedical implants is discussed, followed by an examination of the ability of titanium alloys produced using AM methods. Mechanical properties and other issues relating to the functional application of these biomedical implants are promptly discovered. Further, the effect of bone-implant contact between implants and tissues, which can lead to failure, while advanced methods to improve osteointegration through surface modification of the AM fabricated titanium alloys are also scrutinised

Recent advancement in isolation, processing, characterization and applications of emerging nanocellulose: A review

The emergence of nanocellulose from various natural resources as a promising nanomaterial has been gaining interest for a wide range application. Nanocellulose serves as an excellent candidate since it contributes numerous superior properties and functionalities. In this review, details of the three main nanocellulose categorised: cellulose nanocrystal (CNC), cellulose nanofibril (CNF), and bacterial nanocellulose (BNC) have been described. We focused on the preparation and isolation techniques to produce nanocellulose including alkaline pre-treatment, acid hydrolysis, TEMPO-mediated oxidation, and enzymatic hydrolysis. The surface modification of nanocellulose through esterification, silylation, amidation, phosphorylation, and carboxymethylation to improve the diverse applications has also been reviewed. Some invigorating perspectives on the applications, challenges, and future directions on the relevant issues regarding nanocellulose are also presented

Noise measurement and awareness at construction site – a case study

The construction industry is one of the major sectors in Malaysia. Apart from providing facilities, services and goods it also offers employment opportunities to local and foreign workers. In fact, the construction workers are exposed to high risk of noises being generated from various sources including excavators, bulldozers, concrete mixer and piling machines. Previous studies indicated that the piling and concrete work were recorded as the main source that contributed to the highest level of noise among others. Therefore, the aim of this study is to obtain the level of noise exposure during piling process and to determine the awareness of workers against noise pollution at the construction site. Initially, the reading of noise level was obtained at construction site by using a digital sound level meter (SLM) and noise exposure to the workers was mapped. Readings were taken from four different distances; 5, 10, 15 and 20 meters from the piling machine. Furthermore, a set of questionnaire was also distributed to assess the knowledge of regarding noise pollution at the construction site. The result showed that the mean noise level at 5 meters distance was more than 90 dB, which exceeded the recommended level. Although the level of awareness of regarding the effect of noise pollution is satisfactory but majority of workers (90%) still did not wear ear muffs during working periods. Therefore, the safety module guidelines related to noise pollution controls should be implemented to provide a safe working environment and prevent initial occupational hearing loss

Electronic hand hygiene quality and duration monitoring in pre-school children: a feasibility study

Background: Hand hygiene is regarded as the most important measure to prevent spread of infectious diseases. The aim of this study was to assess the feasibility of a prototype application in an electronic device in educating, stimulating and monitoring hand hygiene quality in young children. Method: A pre-school was provided with an interactive hand hygiene application for two months. The device features an online administrator dashboard for data collection and for monitoring the children's hand washing steps and duration. A good hand washing is defined as hand washing which comprise all of the steps outlined in the World Health Organization (WHO) guidelines. Results: The prototype managed to capture 6882 hand wash performed with an average of 20.85 seconds per hand wash. Washing hands palm to palm was the most frequent (79.9%) step performed, whereas scrubbing fingernails and wrists were the least (56%) steps performed. Conclusions: The device is a good prototype to educate, stimulate and monitor good hand hygiene practices. However, other measures should be undertaken to ensure sustainability of the practices

Healthy hands: development and evaluation of a knowledge transfer program

Introduction: Children in pre-schools are at high risk of getting infections due to overcrowding, minimal awareness of basic hygiene and lack of immunity against microorganisms. Hand hygiene practice should be started at home where parents set good example, followed by formal education in pre-schools, primary and secondary school. This study aimed to develop a comprehensive program on hand hygiene practice in pre-schools. This paper presents the developmental aspects of the program material and the results of its evaluation process in a selected pre-school. Methods: Stage of development involved preparation of song, lyric, video clip, infographic and tablet application. The module was introduced during an intervention day called ‘Healthy Hands’ day. The acceptance of the module was evaluated before and after the intervention day. Evaluation was done by assessing pre-school children by face-to-face interview about knowledge on hand hygiene techniques and routine, such as before or after certain activities. Results: We managed to compose a song in three languages (Malay, English & Arabic), produced a video clip, an infographic and tablet application. A total of 227 children participated. Post intervention evaluation showed significant (p<0.001) increase of knowledge for eight out of eleven handwashing steps. The knowledge on hand hygiene routine i.e. after toilet, after playing outdoor, after sneezing and after playing with pet was also increased significantly. Conclusion: This comprehensive knowledge transfer program significantly improved the children’s hand hygiene techniques and routine and is recommended to be integrated into pre-school curriculum

Herpes simplex encephalitis is linked with selective mitochondrial damage; a post-mortem and in vitro study

Herpes simplex virus type-1 (HSV-1) encephalitis (HSE) is the most commonly diagnosed cause of viral encephalitis in western countries. Despite antiviral treatment, HSE remains a devastating disease with high morbidity and mortality. Improved understanding of pathogenesis may lead to more effective therapies. Mitochondrial damage has been reported during HSV infection in vitro. However, whether it occurs in the human brain and whether this contributes to the pathogenesis has not been fully explored. Minocycline, an antibiotic, has been reported to protect mitochondria and limit brain damage. Minocycline has not been studied in HSV infection. In the first genome-wide transcriptomic study of post-mortem human HSE brain tissue, we demonstrated a highly preferential reduction in mitochondrial genome (MtDNA) encoded transcripts in HSE cases (n = 3) compared to controls (n = 5). Brain tissue exhibited a significant inverse correlation for immunostaining between cytochrome c oxidase subunit 1 (CO1), a MtDNA encoded enzyme subunit, and HSV-1; with lower abundance for mitochondrial protein in regions where HSV-1 was abundant. Preferential loss of mitochondrial function, among MtDNA encoded components, was confirmed using an in vitro primary human astrocyte HSV-1 infection model. Dysfunction of cytochrome c oxidase (CO), a mitochondrial enzyme composed predominantly of MtDNA encoded subunits, preceded that of succinate dehydrogenase (composed entirely of nuclear encoded subunits). Minocycline treated astrocytes exhibited higher CO1 transcript abundance, sustained CO activity and cell viability compared to non-treated astrocytes. Based on observations from HSE patient tissue, this study highlights mitochondrial damage as a critical and early event during HSV-1 infection. We demonstrate minocycline preserves mitochondrial function and cell viability during HSV-1 infection. Minocycline, and mitochondrial protection, offers a novel adjunctive therapeutic approach for limiting brain cell damage and potentially improving outcome among HSE patients

Examination of the host response in brain tissue during herpes simplex virus encephalitis

Background: Herpes simplex virus encephalitis (HSVE) continues to be one of the most devastating infections of the central nervous system (CNS) despite effective antiviral treatment. The pathogenesis of the disease has not been completely studied, and little is known about the molecular mechanisms underlying cellular death and tissue damage. Better understanding of the HSVE pathogenesis is required to develop better treatment and reduce of patients’ morbidity and mortality. Method: Post-mortem brain tissue from adult HSVE (n=3) and road traffic accident (RTA; n=5) cases were examined to characterise the neuropathological changes, immune activation and infiltration of the inflammatory cells, and changes in transcript abundance during herpes simplex virus type 1 (HSV-1) infection. Patients with HIV encephalitis (n=3) provided further control tissue. Results: There was extensive neuropathological change and widespread necrosis in temporal and frontal regions of the brain among the HSVE cases. CNS cells showed characteristic signs of lytic damage. Infection was associated with microglial activation and infiltration by macrophages and lymphocytes. Genome-wide gene-expression micro-array analysis of the brain tissue demonstrated 287 host transcripts with significantly lower abundance in HSVE compared to RTA cases. Mitochondrial DNA encoded transcripts were significantly over-represented in the set of low abundant transcripts (

Recent progress of sol-gel coating of pure magnesium in biomedical applications. A review

Magnesium (Mg) has attracted great attention as a possible biomedical implant due to its appropriate mechanical property, good biocompatibility, and lightweight. However, fast and uneven degradation has been a significant problem of pure Mg. The goal of this review was to investigate the current state of the art in the corrosion resistance and load-bearing capacities of osteopromotive biomaterials created by altering Mg surface coating with Hydroxyapatite (HA) ceramics. Initially, the osteopromotive characteristics of magnesium and also the magnesium corrosion behaviour in the human body’s microenvironment were discussed. Following that, the different HA sol-gel coating methods in modifying the surface and corrosion behaviour of Mg were established. It was proposed that the optimal HA coating is about 5 to 6 µm as a corrosion barrier, which may also be improved by heat treatment at temperatures ranging from 300°C to 450°C. Finally, the strategies of HA sol-gel surface modification to improve the apatite formed and their degradation issue to promote healing in orthopaedic high load-bearing skeletal sites were elucidated

Recent development of natural fibre for nanocellulose extraction and application

Natural fibers garnered fame amongst researchers and scientists due to their potential as an alternative material in countless sectors, including automotive, packaging, construction, and medicine. This work began with the classification of natural fibers and an overview of their chemical compositions. Then, the retting process, which is a process separating the fiber from the woody core, was discussed. The latest technology has attracted researchers’ attention in the alteration of natural fibers to form nanostructures. Hence, this paper will also discuss the extraction method for nanocellulose. Following that, the methods for the preparation of these cellulose nanofibers, which are nanocrystalline cellulose (CNC), nano-fibrillated cellulose (CNF), and bacterial nanocellulose (BNC), are summarized. Finally, the application of this nanomaterial in advanced applications was explored, and a way forward of this nanocellulose technology was also scrutinized

Effect of hand hygiene intervention on the absenteeism of pre-school children in Klang Valley, Malaysia: a quasi-experimental study

Background: Absenteeism amongst pre-school children is often due to illnesses such as hand, foot, and mouth disease, acute gastroenteritis, cold and flu, which are easily spread amongst them. This is because of weak immunity and lack of knowledge on proper hand hygiene. This quasi-experimental study assessed the efficacy of an intervention consisting of a hand hygiene education programme, along with digital tools in bringing about a change in behaviour and health conditions amongst pre-school children in Klang Valley, Malaysia. Methods: A total of 377 school children, male and female, aged 5–6 years old, participated and were assigned to either the intervention or a control group. During the 2 months intervention period, children in the test group were trained on proper hand hygiene practices and techniques with the aid of the interactive android-based tablets. The numbers of absent days of all the children were recorded for 2 months before the intervention and during the intervention. Results: In the test group, there was a 25% increase in the total number of absent days from the pre-intervention period to the intervention period, a much lesser increment observed as compared to that of control group in which the increase was much higher at 89%. Results showed a significant difference (P < 0·05) between the absenteeism rates for the test and control group during the intervention period. Conclusion: These results suggest that proper education and intervention increase hand hygiene compliance, which may help decrease school absenteeism due to illness; however, a longer study duration may be necessary to evaluate the benefit further