Molecular mechanisms for fetal cardiac arrhythmia in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis in pregnancy (ICP) is characterized by raised serum bile acids which can cause fetal complications, including preterm labour and intrauterine death. The fetal death in ICP is not well understood. In this thesis, the mechanisms of bile-acid induced arrhythmia were studied extensively using in vitro models of the fetal heart. Addition of the bile acid taurocholate (TC) to cardiomyocytes led to a reduction in the rate and amplitude of contraction, dysregulation of beating and desynchronization of intracellular calcium release. The results obtained from both differentiated mouse and human embryonic stem cell-derived cardiomyocytes (ESC-CM) demonstrated that immature cardiomyocytes are more susceptible to TC-induced arrhythmias than more mature cardiomyocytes. Although classical hepatic bile acid transporters such as ntcp, mrp2 and mdr2 are expressed in neonatal rat cardiomyocytes, the results suggest that they are unlikely to play role in TC-induced arrhythmia. They also suggest that the bile acid nuclear receptor FXR is not involved as uptake of radioactively labelled TC into the cells is minimal and that there is no functional involvement of the classical hepatic FXR pathways in neonatal rat cardiomyocytes. Similarly, the membrane bile acid receptor TGR5 showed neither immunoreactivity nor functional effects in cardiomyocytes. TC binds to the muscarinic M2 receptor and serves as a partial agonist of this receptor in terms of receptor activation and its inhibitory effect on cAMP in neonatal rat cardiomyocytes. Inhibition of the M2 muscarinic receptor by antagonist and the knockdown of the receptor with siRNA completely abolished the negative effect of TC on cardiomyocyte contraction, calcium transient amplitude and synchronisation in small cell clusters. In conclusion, immature ESC-CMs are more susceptible to TC and this effect is lost as cells progress to more mature phenotypes. Moreover, the findings suggest the arrhythmogenic effect of TC in neonatal cardiomyocytes is mediated by the muscarinic M2 receptor. This mechanism might serve as a promising new therapeutic target for fetal arrhythmia

Modeling Mode Choice Behavior of Motorcyclists in Malaysia

In Malaysia, motorcycle use has grown in popularity in the past decades and this has resulted in increased casualties among motorcyclists. However, earlier studies focused primarily on motorcycle safety issues rather than identifying factors that influence motorcycle use and motorcyclists’ mode choice behavior. To overcome these problems, this study focused on the concept of exposure control measures such as an alternative to road transport as a countermeasure aimed at shifting motorcycle users to other safer modes in order to reduce the number of motorcycle road accidents. This study developed a model for motorcyclist mode choice behavior and potential mode shift from the motorcycle to other safer modes. A cross-sectional survey of mode choice among bus, car and motorcycle users in Selangor state, Malaysia was conducted. Selangor state was chosen for the study as it has the highest number of motorcycle crashes in Malaysia. A total of 810 randomly self-administered questionnaires were collected from the household surveys for each mode user over a period of 6 months. Among the data collected were the demographic details, such as income, age, gender, and educational level, trip characteristics, and travel behavior of each mode user. In order to assess the relative importance of demographic, socio-economic and service attributes that influence travelers’ mode choice behavior, discrete choice models were developed in the form of a binomial logit (when there are only two choices), and the multinomial logit (when there are more than two choices) For the motorcycle and bus model, the results suggested that travel time and travel cost are characteristics that determine why motorcycle use is the favored modal choice. The estimated coefficients for travel time and travel cost for the bus mode are negative, implying that an increase in travel time and travel cost for the bus mode is likely to increase the probability of a motorcyclist to continue choosing the motorcycle as the preferred mode of transport. In order to promote greater use of public transport services, the study examined the probability of motorcycle riders shifting to public transport based on a scenario of a reduction in bus travel time and travel cost. The results of the predicted mode share probability show that when the bus and motorcycle are equally fast, 38% would use the motorcycle and 62% the bus The motorcycle and car model examined the influence of future income and car ownership on model shift. The results of the model predict that when the income level of motorcyclists reaches RM 2500 (about US$700) per month, the probability of motorcycle use would drop from 80% to 57%. At the same time, the probability of car commuters would increase from 20% to 41%. According to a World Bank study, if the current rates of economic growth continue uninterrupted, per capita income for Malaysia is expected to reach RM 2000 by the year 2013. According to our 8th Malaysia plan, the per capita income growth target under Vision 2020 is expected to be RM 3166. Therefore, a 29% reduction in motorcycle use is expected to be achieved between years 2013-2020. Similar trends were found for household car ownership. The results showed that ownership of one car in the household would result in a 14% reduction in motorcycle use, while ownership of two cars would result in a 42% reduction in motorcycle use relative to car use. Therefore, the study suggests that improvements in motorcyclists’ income and car ownership would have the greatest impact in influencing the mode preference of motorcyclists, and result in a significant reduction in motorcycle use and a shift towards safer modes of transport

An overview of mercury emission sources and application of activated carbon for mercury removal from flue gas / Hidayu Abdul Rani ... [et al.]

Mercury emission into the atmosphere is a global concern due to its detrimental effects on human health in general. The two main sources of mercury emission are natural sources and anthropogenic sources. Mercury emission from natural sources include volcanic activity, weathering of rocks, water movement and biological processes which are obviously inevitable. The anthropogenic sources of mercury emission are from coal combustion, cement production and waste incineration. Thus, in order to reduce mercury emission it is appropriate to investigate how mercury is released from the anthropogenic sources and consequently the mercury removal technology that can be implemented in order to reduce mercury emission into the atmosphere. Many alternatives have been developed to reduce mercury emission and the recent application of activated carbon showed high potential in the adsorption of elemental mercury. This paper discusses the ability of activated carbon and variable parameters that influence mercury removal efficiency in flue gas

Aloe emodin induces apoptosis in ER+-breast cancer cells; MCF-7 through IGF-1R signalling pathway

Two-third of breast cancer patients expressed estrogen receptors (ER)s and received endocrine treatment with established anti-estrogens such as tamoxifen. But the action and acquired resistance during treatment are largely unknown. In contrary, phytochemicals are more selective and less cytotoxic to normal cells. Accordingly, we found aloe emodin, an anthraquinone to inhibit the proliferation of ER+-breast cancer cells, MCF-7 with IC50 of 80 μM, but not affecting control breast cells, MCF-10A. Tamoxifen was non-selective to both cells with IC50 of 27 and 38 μM, respectively. Thus, we aimed to investigate the anti-proliferative mechanism of aloe emodin on MCF-7 and its underlying signalling compared to tamoxifen. Cells were treated separately with aloe emodin and tamoxifen at respective IC50 for 72 h. Apoptosis was determined using Annexin V-FITC/PI staining. The expression of insulin-like growth factor-1 receptor (IGF-1R), insulin-like growth factor binding protein (IGFBP)-2 and B-raf gene was investigated using QuantiGene 2.0 Plex assay. Paired-student t-test and ANOVA test were used to compare between untreated and treated cells on the measured parameters. Each treatment was conducted in triplicate and repeated three times. Significance was set at p<0.05. The presences of early and late apoptosis in MCF-7 were seen in both treatments. All target genes were down regulated. The anti-proliferation effect of aloe emodin on MCF-7 is similar with tamoxifen which mediates inhibition of IGF-1R signalling pathway. This suggests aloe emodin as a potential anti-cancer agent to be used in combined anti-estrogen therapy to enhance its efficacy in ER+-breast cancer treatment

Removal of As(III) and As(V) from water using green, silica-based ceramic hollow fibre membranes via direct contact membrane distillation

Arsenite [As(III)] and arsenate [As(V)] removal by direct contact membrane distillation (DCMD) using novel hydrophobic green, silica-based ceramic hollow fibre membranes derived from agricultural rice husk was investigated in this work. The green ceramic hollow fibre membranes were prepared from amorphous (ASHFM) and crystalline (CSHFM) silica-based rice husk ash and modified to be hydrophobic via immersion fluoroalkylsilane (FAS) grafting of 1H,1H,2H,2H-perfluorodecyltriethoxysilane. Superhydrophobic contact angle values up to 157° and 161° were obtained for ASHFM and CSHFM, respectively. Remarkably, the membrane surface morphology mimicked a look-alike lotus-leaf structure with decrement in pore size after grafting via the silane agent for both membranes. The effect of arsenic pH (3–11), arsenic concentration (1–1000 ppm) and feed temperature (50–80 °C) were studied and it was found that feed temperature had a significant effect on the permeate flux. The hydrophobic CSHFM, with a flux of 50.4 kg m−2 h−1 for As(III) and 51.3 kg m−2 h−1 for As(V), was found to be the best of the tested membranes. In fact, this membrane can reject arsenic to the maximum contaminant level (MCL) limit of 10 ppb under any conditions, and no swelling mechanism of the membranes was observed after testing for 4 hours

Effects of bisphenol a on neonatal cardiomyocytes beating rate and morphology

Bisphenol A (BPA) has been utilised excessively at a global capacity of 2.9 billion kg/year. It is widely used in manufacturing polycarbonate polymers and epoxy resins. Hence, humans are potentially exposed to this chemical substance in their daily life. As a typical endocrine disruptor, BPA exhibits detectable hormone-like properties. Many studies have been linking BPA exposure in humans with the risk of developing cardiovascular disease, however the direct exposure of BPA on cardiomyocytes beating rates and morphology have not been entirely explored. Therefore, in this study, we aimed to investigate the effects of BPA on cells structure and function of neonatal rat cardiomyocytes culture. Cardiomyocytes were isolated from 0 to 2 days old newborn rats and treated with 0.001 to 100 µM concentration of BPA. All cardiomyocytes were subjected to immunostaining, beating frequency assessment assay, MTS assay and Scanning Electron microscopy (SEM). In immunostaining, cardiomyocytes showed positive staining for F-actin. This staining allows identification of the cells thus differentiate cardiomyocytes from other cell types. Significance effects of BPA on cardiomyocytes were observed in MTS assay (p<0.05) and beating rates (p<0.01). Significant reduction (48%-64%, ± 1.5280) was observed in beating rate of cardiomyocytes exposed to 0.1 to 100 µM of BPA. Meanwhile in MTS assay, significant reduction (54%, 0.067 ± 0.0026) in cell viability was observed in cells exposed to 0.1 µM of BPA only. Interestingly, under SEM, cardiomyocytes showed altered cell surface homogeneity after BPA exposure. Exposure of 0.1 to 100 µM BPA lead to flatten of cardiomyocytes cell surface and blurring of the cell borders. This study offers an in vitro evidence of BPA effects on cardiomyocytes morphology and beating rates, thus suggest the potential adverse effect of BPA exposure. However, further investigation would be required to understand how BPA effects normal cells morphology and beating rates of heart cells

Weight Prediction for Fishes in Setiu Wetland, Terengganu, using Machine Learning Regression Model

Predicting fish weight holds several essential implications in ecology, such as population assessment, trophic interactions within ecosystems, biodiversity studies of fish communities, ecosystem modelling, habitat evaluation for different fish species, climate change research, and support fisheries management practices. The objective of the studies is to analyse the prediction performance of machine learning (ML) regression models by applying different statistical analysis techniques. This study collected biometric measurements (total length and body weight) for 19 fish families from three locations in Setiu Wetland, Terengganu, captured between 2011 and 2012. The study adopts two regression types: Linear Regression (i.e., Multiple Linear, Lasso, and Ridge model) and Tree-based Regression (i.e., Decision Tree, Random Forest, and XGBoost model). Mean absolute error (MAE), root-mean-square error (RMSE), and coefficient of determination (R2) were used to evaluate performance. The results showed that the proposed ML regression models successfully predicted fish weight in Setiu Wetlands, and the Tree-based Regression model provides more accurate prediction results than the Linear Regression model. As a result, Random Forest is the best predictive model out of the six suggested ML regressions, with the highest accuracy at 96.1% and the lowest RMSE and MAE scores at 3.352 and 0.880, respectively. In conclusion, the use of machine learning is crucial for rapid, precise, and cost-effective fish weight measurement. By incorporating weight prediction into ecological research and management practices, we may make informed decisions supporting the conservation and sustainable use of fish populations and their habitats

Low concentration of Bisphenol a induces proliferation of gastric cancer cells, HGC-27

Bisphenol A, an endocrine disrupting compound that affects human homeostasis. Studies on BPA are focusing on the impact of BPA in reproductive function and brain development. However, the effect of BPA on gut especially gastric cells is not well explored. Gut is directly in contact with ingested BPA; therefore, we aimed to determine the effect of BPA exposure on gastric cells proliferation at safe recommended concentration. Human gastric cancer cells (HGC-27) were treated with BPA at different concentration (low: 10-9M, 10-7M; high10-5M, 10-4M) and time point (24 hr, 48 hr, 72 hr). Cell viability assays were determined using MTS assay. Cells were further stained with Alexa Fluor-635 (F-actin) and Fluorescein (Hif-1α) protein for immunocytofluorescence. Data were analysed using ANOVA (p<0.05, n≥3). Cells treated with 10-9M BPA showed significance increase of cell viability after 48 hr (Mean ±SEM; 146%±0.03, p=0.01) and 72 hr (113%±0.03, p=0.00) compared to 24 hr treatment (77%±0.11, p=0.002). Similarly, cell treated with 10-7M BPA showed a significance increase after 48 hr (141%±0.03, p=0.03) and 72 hr (190%±0.03, p=0.02) compared to 24 hr cells treated with 10-7M (88%±0.05, p=0.01) and untreated (100%±0.07). Lower concentration of BPA increases the condensation of F-actin in all HGC-27 cells. Meanwhile, translocation of Hif-1α protein were observed in all BPA-exposed cells. Findings of this study revealed that BPA induced proliferation and condensation of F-actin structure of gastric cancer cells at low concentration

Polysulfone hemodialysis membrane incorporated with Fe2O3 for enhanced removal of middle molecular weight uremic toxin

Removing middle molecular weight uremic toxin remains as one of the most challenging tasks in hemodialysis. Hence, in this study a high performance polysulfone (PSf) hemodialysis membrane was developed by incorporating iron oxide (Fe2O3) nanoparticles. The PSf/Fe2O3 hemodialysis membrane and pristine PSf membrane were prepared via dry-wet spinning process. The membranes were characterized by scanning electron microscopy, water contact angle, average pore size, and porosity measurements. The biocompatibility profiles of the membranes were also evaluated in terms of protein adsorption and blood coagulation time. Next, the performance of the membranes was determined by measuring pure water permeability (PWP), bovine serum albumin rejection, and removal of various solutes such as urea and lysozyme. The incorporation of Fe2O3 resulted in significant increment of the PWP from 40.74 L/m2/h/bar to 58.6 L/m2/h/bar, mainly due to the improved water transport properties of the membrane. Moreover, the percent removal of urea and lysozyme was reported to be 75.1% and 35.6%, respectively. PSf/Fe2O3 hemodialysis membrane is proven to have a bright prospect for enhanced blood purification process

High flux polysulfone braided hollow fiber membrane for wastewater treatment role of zinc oxide as hydrophilic enhancer

Incorporation of zinc oxide (ZnO) nanoparticles has played an important role on the improvement of unique membrane characterization and performance, most notably the hydrophilic modification of the membrane for higher pure water permeability. Additionally, the permeability of the membrane can be improved via introduction of braid support by reducing the thickness of the membrane separation layer. Moreover, the braided hollow fiber membrane (BHFM) is able to perform under higher pressure conditions compared to hollow fiber membranes. In this paper, hybrid polysulfone (PSf)/ZnO BHFMs were fabricated via phase inversion method. Hydrophilic 10 ± 1.8 nm polycrystalline ZnO nanoparticles synthesized via sol-gel method were incorporated on BHFM to improve the hydrophilicity and increase flux with constant rejection under high pressure and the effect of the ZnO loading on the membrane properties and performance were thoroughly studied. The fabricated BHFMs with 0.0, 0.5, 1.0 and 1.5 wt% of ZnO nanoparticles concentration were defined as BHFM1, BHFM2, BHFM3 and BHFM4 respectively. Scanning electron microscopy (SEM), contact angle, mechanical strength, flux performance, rejection with bovine serum albumin (BSA) and fouling of best performed membrane were conducted to achieve the target of this paper. The performance of these hybrid ZnO/PSf BHFMs were compared with neat PSf hollow fiber membrane (HFM) and previous studies. The findings from this research work shows that BHFM4 has the most desired properties for wastewater treatment application. The ZnO nanoparticles in BHFM4 have improved hydrophilicity from 108.79° to 71.02°, and thus BHFM4 has increased flux performance from 36.20 to 919.12 L/m2 h at 1.0 bar pressure and 193.48 to 1909.11 L/m2h at 4.0 bar pressure when compared with BHFM1. Constant BSA rejection rates (> 90%) were observed in all BHFMs. The improved hydrophilicity and pure flux performance with constant rejection rate in high pressure conditions illustrates the suitability of fabricated ZnO/PSf BHFMs in wastewater treatment applications