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Fulltext Blechnum orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

Lai HY, Lim YY, Kim KH

BMC Complement Altern Med, 2010;10:15.
PMID: 20429956 DOI: 10.1186/1472-6882-10-15

Blechnum orientale Linn. (Blechnaceae) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of Blechnum orientale Linn.
Thermal comfort study of hospital workers in Malaysia

Yau YH, Chew BT

Indoor Air, 2009 Dec;19(6):500-10.
PMID: 19719535 DOI: 10.1111/j.1600-0668.2009.00617.x

This article presents findings of the thermal comfort study in hospitals. A field survey was conducted to investigate the temperature range for thermal comfort in hospitals in the tropics. Thermal acceptability assessment was conducted to examine whether the hospitals in the tropics met the ASHRAE Standard-55 80% acceptability criteria. A total of 114 occupants in four hospitals were involved in the study. The results of the field study revealed that only 44% of the examined locations met the comfort criteria specified in ASHRAE Standard 55. The survey also examined the predicted percentage of dissatisfied in the hospitals. The results showed that 49% of the occupants were satisfied with the thermal environments in the hospitals. The field survey analysis revealed that the neutral temperature for Malaysian hospitals was 26.4 degrees C. The comfort temperature range that satisfied 90% of the occupants in the space was in the range of 25.3-28.2 degrees C. The results from the field study suggested that a higher comfort temperature was required for Malaysians in hospital environments compared with the temperature criteria specified in ASHRAE Standard (2003). In addition, the significant deviation between actual mean vote and predicted mean vote (PMV) strongly implied that PMV could not be applied without errors in hospitals in the tropics.
Fulltext The ventilation of multiple-bed hospital wards in the tropics: A review

Yau YH, Chandrasegaran D, Badarudin A

Build Environ, 2011 May;46(5):1125-1132.
PMID: 32288016 DOI: 10.1016/j.buildenv.2010.11.013

Hospital and healthcare facilities have diverse indoor environment due to the different comfort and health needs of its occupants. Currently, most ventilation studies revolve around specialised areas such as operating rooms and isolation rooms. This paper focuses on the ventilation of multiple-bed hospital wards in the tropical climate, taking into account the design, indoor conditions and engineering controls. General ward layouts are described briefly. The required indoor conditions such as temperature, humidity, air movements and indoor air quality in the ward spaces are summarized based on the current guidelines and practices. Also, recent studies and engineering practices in the hospital indoor environment are elaborated. Usage of computational fluid dynamics tools for the ventilation studies is discussed as well. As identified during the review, there is an apparent knowledge gap for ventilation studies in the tropics compared with temperate climates, as fact studies have only been published for hospital wards in countries with a temperate climate. Therefore, it is highlighted that specific tropical studies along with novel engineering controls are required in addressing the ventilation requirements for the tropics.
Finite element analysis on longitudinal and radial functionally graded femoral prosthesis

Oshkour AA, Abu Osman NA, Davoodi MM, Yau YH, Tarlochan F, Wan Abas WA, et al.

Int J Numer Method Biomed Eng, 2013 Dec;29(12):1412-27.
PMID: 23922316 DOI: 10.1002/cnm.2583

This study focused on developing a 3D finite element model of functionally graded femoral prostheses to decrease stress shielding and to improve total hip replacement performance. The mechanical properties of the modeled functionally graded femoral prostheses were adjusted in the sagittal and transverse planes by changing the volume fraction gradient exponent. Prostheses with material changes in the sagittal and transverse planes were considered longitudinal and radial prostheses, respectively. The effects of cemented and noncemented implantation methods were also considered in this study. Strain energy and von Mises stresses were determined at the femoral proximal metaphysis and interfaces of the implanted femur components, respectively. Results demonstrated that the strain energy increased proportionally with increasing volume fraction gradient exponent, whereas the interface stresses decreased on the prostheses surfaces. A limited increase was also observed at the surfaces of the bone and cement. The periprosthetic femur with a noncemented prosthesis exhibited higher strain energy than with a cemented prosthesis. Radial prostheses implantation displayed more strain energy than longitudinal prostheses implantation in the femoral proximal part. Functionally graded materials also increased strain energy and exhibited promising potentials as substitutes of conventional materials to decrease stress shielding and to enhance total hip replacement lifespan.
Design of new generation femoral prostheses using functionally graded materials: a finite element analysis

Oshkour AA, Abu Osman NA, Yau YH, Tarlochan F, Abas WA

Proc Inst Mech Eng H, 2013 Jan;227(1):3-17.
PMID: 23516951

This study aimed to develop a three-dimensional finite element model of a functionally graded femoral prosthesis. The model consisted of a femoral prosthesis created from functionally graded materials (FGMs), cement, and femur. The hip prosthesis was composed of FGMs made of titanium alloy, chrome-cobalt, and hydroxyapatite at volume fraction gradient exponents of 0, 1, and 5, respectively. The stress was measured on the femoral prosthesis, cement, and femur. Stress on the neck of the femoral prosthesis was not sensitive to the properties of the constituent material. However, stress on the stem and cement decreased proportionally as the volume fraction gradient exponent of the FGM increased. Meanwhile, stress became uniform on the cement mantle layer. In addition, stress on the femur in the proximal part increased and a high surface area of the femoral part was involved in absorbing the stress. As such, the stress-shielding area decreased. The results obtained in this study are significant in the design and longevity of new prosthetic devices because FGMs offer the potential to achieve stress distribution that more closely resembles that of the natural bone in the femur.
Fulltext An investigation of the PM2.5 concentrations and cumulative inhaled dose during subway commutes in Changchun, China

Chang L, Chong WT, Yau YH, Cui T, Wang XR, Pei F, et al.

Int J Environ Sci Technol (Tehran), 2023 May 24.
PMID: 37360559 DOI: 10.1007/s13762-023-04994-7

Air quality in subway systems is crucial as it affects the health of passengers and staff. Although most tests of PM2.5 concentrations in subway stations have taken place in public areas, PM2.5 is less understood in workplaces. Few studies have estimated the cumulative inhaled dose of passengers based on real-time changes in PM2.5 concentrations as they commute. To clarify the above issues, this study first measured PM2.5 concentrations in four subway stations in Changchun, China, where measuring points included five workrooms. Then, passengers' exposure to PM2.5 during the whole subway commute (20-30 min) was measured and segmented inhalation was calculated. The results showed that PM2.5 concentration in public places ranged from 50 to 180 μg/m3, and was strongly correlated with outdoors. While the PM2.5 average concentration in workplaces was 60 µg/m3, and it was less affected by outdoor PM2.5 concentration. Passenger's cumulative inhalations in single commuting were about 42 μg and 100 μg when the outdoor PM2.5 concentrations were 20-30 μg/m3 and 120-180 μg/m3, respectively. The PM2.5 inhalation in carriages accounted for the largest proportion of the entire commuting, about 25-40%, because of the longer exposure time and higher PM2.5 concentrations. It is recommended to improve the tightness of the carriage and filter the fresh air to improve the air quality inside. The average daily PM2.5 inhaled by staff was 513.53 μg, which was 5-12 times higher than that of passengers. Installing air purification devices in workplaces and reminding staff to take personal protection can positively protect their health.
Developments in understanding and applying prebiotics in research and practice-an ISAPP conference paper

Scott KP, Grimaldi R, Cunningham M, Sarbini SR, Wijeyesekera A, Tang MLK, et al.

J Appl Microbiol, 2020 Apr;128(4):934-949.
PMID: 31446668 DOI: 10.1111/jam.14424

AIMS: The concept of using specific dietary components to selectively modulate the gut microbiota to confer a health benefit, defined as prebiotics, originated in 1995. In 2018, a group of scientists met at the International Scientific Association for Probiotics and Prebiotics annual meeting in Singapore to discuss advances in the prebiotic field, focussing on issues affecting functionality, research methodology and geographical differences.
METHODS AND RESULTS: The discussion ranged from examining scientific literature supporting the efficacy of established prebiotics, to the prospects for establishing health benefits associated with novel compounds, isolated from different sources.
CONCLUSIONS: While many promising candidate prebiotics from across the globe have been highlighted in preliminary research, there are a limited number with both demonstrated mechanism of action and defined health benefits as required to meet the prebiotic definition. Prebiotics are part of a food industry with increasing market sales, yet there are great disparities in regulations in different countries. Identification and commercialization of new prebiotics with unique health benefits means that regulation must improve and remain up-to-date so as not to risk stifling research with potential health benefits for humans and other animals.
SIGNIFICANCE AND IMPACT OF STUDY: This summary of the workshop discussions indicates potential avenues for expanding the range of prebiotic substrates, delivery methods to enhance health benefits for the end consumer and guidance to better elucidate their activities in human studies.
Knowledge and Attitudes Towards Pregnancy in Females with Inflammatory Bowel Disease: An International, Multi-centre Study

Laube R, Yau Y, Selinger CP, Seow CH, Thomas A, Wei Chuah S, et al.

J Crohns Colitis, 2020 Sep 16;14(9):1248-1255.
PMID: 32191292 DOI: 10.1093/ecco-jcc/jjaa047

BACKGROUND AND AIMS: Poor knowledge of inflammatory bowel disease [IBD] in pregnancy underlies unwarranted voluntary childlessness [VC], and risks poorer obstetric outcomes and adverse fetal outcomes. IBD is increasing worldwide but education on IBD issues might be heterogeneous based on cultural differences and variations in models of care.
METHODS: Consecutive female IBD subjects aged 18-45 years were prospectively recruited from two dedicated IBD-pregnancy clinics, two multidisciplinary IBD clinics and nine general gastroenterology clinics. Subjects completed the validated CCPKnow [score 0-17] with questions on demographics, medical history and pregnancy knowledge. The primary outcome was knowledge per clinic-type and per geographical region.
RESULTS: Surveys were completed by 717 subjects from 13 hospitals across ten countries. Dedicated IBD-pregnancy clinics had the highest knowledge, followed by multidisciplinary IBD clinics then general IBD clinics (median CCPKnow 10.0 [IQR: 8.0-11.0], 8.0 [IQR: 5.0-10.5] and 4.0 [IQR:2.0-6.0]; p