MyMedR

Displaying publications 61 - 69 of 69 in total

Abstract:

Sort:

Energy balance and life cycle assessments in producing microalgae biodiesel via a continuous microalgal-bacterial photobioreactor loaded with wastewater

Leong WH, Lim JW, Rawindran H, Liew CS, Lam MK, Ho YC, et al.

Chemosphere, 2023 Nov;341:139953.
PMID: 37634592 DOI: 10.1016/j.chemosphere.2023.139953

Life cycle assessments of microalgal cultivation systems are often conducted to evaluate the sustainability and feasibility factors of the entire production chain. Unlike widely reported conventional microalgal cultivation systems, the present work adopted a microalgal-bacterial cultivation approach which was upscaled into a pilot-scale continuous photobioreactor for microalgal biomass production into biodiesel from wastewater resources. A multiple cradle-to-cradle system ranging from microalgal biomass-to-lipid-to-biodiesel was evaluated to provide insights into the energy demand of each processes making up the microalgae-to-biodiesel value chain system. Energy feasibility studies revealed positive NER values (4.95-8.38) for producing microalgal biomass but deficit values for microalgal-to-biodiesel (0.14-0.23), stemming from the high energy input requirements in the downstream processes for converting biomass into lipid and biodiesel accounting to 88-90% of the cumulative energy demand. Although the energy balance for microalgae-to-biodiesel is in the deficits, it is comparable with other reported biodiesel production case studies (0.12-0.40). Nevertheless, the approach to using microalgal-bacterial cultivation system has improved the overall energy efficiency especially in the upstream processes compared to conventional microalgal cultivation systems. Energy life cycle assessments with other microalgal based biofuel systems also proposed effective measures in increasing the energy feasibility either by utilizing the residual biomass and less energy demanding downstream extraction processes from microalgal biomass. The microalgal-bacterial cultivation system is anticipated to offer both environmental and economic prospects for upscaling by effectively exploiting the low-cost nutrients from wastewaters via bioconversion into valuable microalgal biomass and biodiesel.

Matched MeSH terms: Life Cycle Stages
Perspectives on cultivation and harvesting technologies of microalgae, towards environmental sustainability and life cycle analysis

Soudagar MEM, Kiong TS, Jathar L, Nik Ghazali NN, Ramesh S, Awasarmol U, et al.

Chemosphere, 2024 Apr;353:141540.
PMID: 38423144 DOI: 10.1016/j.chemosphere.2024.141540

The development of algae is seen as a potential and ecologically sound approach to address the increasing demands in multiple sectors. However, successful implementation of processes is highly dependent on effective growing and harvesting methods. The present study provides a complete examination of contemporary techniques employed in the production and harvesting of algae, with a particular emphasis on their sustainability. The review begins by examining several culture strategies, encompassing open ponds, closed photobioreactors, and raceway ponds. The analysis of each method is conducted in a systematic manner, with a particular focus on highlighting their advantages, limitations, and potential for expansion. This approach ensures that the conversation is in line with the objectives of sustainability. Moreover, this study explores essential elements of algae harvesting, including the processes of cell separation, dewatering, and biomass extraction. Traditional methods such as centrifugation, filtration, and sedimentation are examined in conjunction with novel, environmentally concerned strategies including flocculation, electro-coagulation, and membrane filtration. It evaluates the impacts on the environment that are caused by the cultivation process, including the usage of water and land, the use of energy, the production of carbon dioxide, and the runoff of nutrients. Furthermore, this study presents a thorough examination of the current body of research pertaining to Life Cycle Analysis (LCA) studies, presenting a perspective that emphasizes sustainability in the context of algae harvesting systems. In conclusion, the analysis ends up with an examination ahead at potential areas for future study in the cultivation and harvesting of algae. This review is an essential guide for scientists, policymakers, and industry experts associated with the advancement and implementation of algae-based technologies.

Matched MeSH terms: Life Cycle Stages
Fulltext Clostridia isolated from helminth-colonized humans promote the life cycle of Trichuris species

Sargsian S, Chen Z, Lee SC, Robertson A, Thur RS, Sproch J, et al.

Cell Rep, 2022 Nov 29;41(9):111725.
PMID: 36450245 DOI: 10.1016/j.celrep.2022.111725

Soil-transmitted intestinal worms known as helminths colonize over 1.5 billion people worldwide. Although helminth colonization has been associated with altered composition of the gut microbiota, such as increases in Clostridia, individual species have not been isolated and characterized. Here, we isolate and sequence the genome of 13 Clostridia from the Orang Asli, an indigenous population in Malaysia with a high prevalence of helminth infections. Metagenomic analysis of 650 fecal samples from urban and rural Malaysians confirm the prevalence of species corresponding to these isolates and reveal a specific association between Peptostreptococcaceae family members and helminth colonization. Remarkably, Peptostreptococcaceae isolated from the Orang Asli display superior capacity to promote the life cycle of whipworm species, including hatching of eggs from Trichuris muris and Trichuris trichiura. These findings support a model in which helminths select for gut colonization of microbes that support their life cycle.

Matched MeSH terms: Life Cycle Stages
Life history of Spodoptera exigua (Lepidoptera: Noctuidae) on various host plants

Azidah AA, Sofian-Azirun M

Bull. Entomol. Res., 2006 Dec;96(6):613-8.
PMID: 17201979

The incubation period of Spodoptera exigua (Hübner) was not influenced by the host plant, whereas larval development time and pupal period were affected. Larval development time was longest on shallot and lady's finger, followed by cabbage and long bean. Larvae did not develop beyond the first instar when fed on chilli. The pupal period was longer on lady's finger than on cabbage, shallot and long bean. Overall, adult longevity was not influenced by the host plant but there was a difference between female and male longevity among the host plants. Survival of S. exigua was affected by the host plant at the larval stage. The number of larval instars varied between 5 and 8 within and between the studied host plants. Long bean was found to be the most suitable host plant and provide the best food quality for S. exigua compared to the other host plants, as it allowed faster development, fewer larval instars and a higher survival rate.

Matched MeSH terms: Life Cycle Stages/physiology*
Algae biopolymer towards sustainable circular economy

Devadas VV, Khoo KS, Chia WY, Chew KW, Munawaroh HSH, Lam MK, et al.

Bioresour Technol, 2021 Apr;325:124702.
PMID: 33487515 DOI: 10.1016/j.biortech.2021.124702

The accumulation of conventional petroleum-based polymers has increased exponentially over the years. Therefore, algae-based biopolymer has gained interest among researchers as one of the alternative approaches in achieving a sustainable circular economy around the world. The benefits of microalgae biopolymer over other feedstock is its autotrophic complex to reduce the greenhouse gases emission, rapid growing ability with flexibility in diverse environments and its ability to compost that gives greenhouse gas credits. In contrast, this review provides a comprehensive understanding of algae-based biopolymer in the evaluation of microalgae strains, bioplastic characterization and bioplastic blending technologies. The future prospects and challenges on the algae circular bioeconomy which includes the challenges faced in circular economy, issues regard to the scale-up and operating cost of microalgae cultivation and the life cycle assessment on algal-based biopolymer were highlighted. The aim of this review is to provide insights of algae-based biopolymer towards a sustainable circular bioeconomy.

Matched MeSH terms: Life Cycle Stages
Fulltext A clinical tool to predict Plasmodium vivax recurrence in Malaysia

Mat Ariffin N, Islahudin F, Kumolosasi E, Makmor-Bakry M

BMC Infect Dis, 2017 12 08;17(1):759.
PMID: 29216842 DOI: 10.1186/s12879-017-2868-9

BACKGROUND: Recurrence rates of Plasmodium vivax infections differ across various geographic regions. Interestingly, South-East Asia and the Asia-Pacific region are documented to exhibit the most frequent recurrence incidences. Identifying patients at a higher risk for recurrences gives valuable information in strengthening the efforts to control P. vivax infections. The aim of the study was to develop a tool to identify P. vivax- infected patients that are at a higher risk of recurrence in Malaysia.
METHODS: Patient data was obtained retrospectively through the Ministry of Health, Malaysia, from 2011 to 2016. Patients with incomplete data were excluded. A total of 2044 clinical P. vivax malaria cases treated with primaquine were included. Data collected were patient, disease, and treatment characteristics. Two-thirds of the cases (n = 1362) were used to develop a clinical risk score, while the remaining third (n = 682) was used for validation.
RESULTS: Using multivariate analysis, age (p = 0.03), gametocyte sexual count (p = 0.04), indigenous transmission (p = 0.04), type of treatment (p = 0.12), and incomplete primaquine treatment (p = 0.14) were found to be predictors of recurrence after controlling for other confounding factors; these predictors were then used in developing the final model. The beta-coefficient values were used to develop a clinical scoring tool to predict possible recurrence. The total scores ranged between 0 and 8. A higher score indicated a higher risk for recurrence (odds ratio [OR]: 1.971; 95% confidence interval [CI]: 1.562-2.487; p ≤ 0.001). The area under the receiver operating characteristic (ROC) curve of the developed (n = 1362) and validated model (n = 682) was of good accuracy (ROC: 0.728, 95% CI: 0.670-0.785, p value

Matched MeSH terms: Life Cycle Stages
Fulltext Effect of selected local medicinal plants on the asexual blood stage of chloroquine resistant Plasmodium falciparum

Mohd Abd Razak MR, Afzan A, Ali R, Amir Jalaluddin NF, Wasiman MI, Shiekh Zahari SH, et al.

BMC Complement Altern Med, 2014;14:492.
PMID: 25510573 DOI: 10.1186/1472-6882-14-492

The development of resistant to current antimalarial drugs is a major challenge in achieving malaria elimination status in many countries. Therefore there is a need for new antimalarial drugs. Medicinal plants have always been the major source for the search of new antimalarial drugs. The aim of this study was to screen selected Malaysian medicinal plants for their antiplasmodial properties.

Matched MeSH terms: Life Cycle Stages
Fulltext Ultrasructure of THe Crown and Root Odontoblasts

Mohd. Bakri, M., Whittaker, D.A.

Ann Dent, 2003;10(1):-.
MyJurnal

The ultrastructure of the odontoblast reflects the certain phases that the cell undergoes in their lifecycle. Ultrastructure studies of the odontoblasts have often been carried out using young teeth. In this study, teeth from an older individual have been used to study the odontoblasts from the crown and root area. The odontoblasts from the crown area retain their columnar shape while odontoblasts from the root area appeared to be flattened. The organelles present in the odontoblasts either from the crown or root area was observed to be reduced.

Matched MeSH terms: Life Cycle Stages
The prevalence and intensity of Amblyomma javanense infestation on Malayan pangolins (Manis javanica Desmarest) from Peninsular Malaysia

Hassan M, Sulaiman MH, Lian CJ

Acta Trop, 2013 May;126(2):142-5.
PMID: 23416121 DOI: 10.1016/j.actatropica.2013.02.001

A parasitological survey of 16 pangolins, confiscated from the Department of Wildlife and Nature Park Peninsular Malaysia (DWNP) at Kelantan and Pulau Pinang, Malaysia was conducted in 2011. Amblyomma javanense (family: Ixodidae) was the only ectoparasite found on the pangolins. The prevalence, intensity and life cycle of A. javanense were observed together with the respective pangolins' age and sex. It was found that 68.8% of the pangolins were infected, and significant difference, χ(2)(1, N=16)=4.02, p=0.05 were observed with males higher in infestation (88.9%) as compared to the females (42.9%). However, the mean intensity was higher on females (72) as compared to males (31.6). In addition, significant difference, χ(2) (2, N=16)=6.73, p=0.05 was recorded between adults and juveniles with juveniles found to be 100% infected as compared to adult (63.6%). Nevertheless, the mean intensity was slightly higher on adults (47) than juveniles (35). Adult ticks were found in higher numbers as compared to the nymph and larvae with number of male ticks higher (236) as compared to the females (53). Similarly, a high significant difference χ(2)(2, N=469)=203.47, p=0.05 was recorded in the composition of the tick's life stages with a higher number of adult ticks (61.6%) followed by nymph (30.3%) and larvae (8.1%). As such, the results of this study revealed a picture of the A. javanense life cycle which is related to the age and gender of the Malayan Pangolin.

Matched MeSH terms: Life Cycle Stages