Displaying all 4 publications

Abstract:
Sort:
  1. Kee CY, Hassan M, Ramachandran KB
    PMID: 10595438
    The objective of this research was to study the kinetics of synthesis of a commercially important ester - Isopropyl Palmitate (IPP) using immobilized lipase (Lipozyme IM). It was studied in a packed bed differential reactor. In order to establish the kinetics of the reaction, parameters such as linear velocity of the fluid through the reactor, particle size, substrate concentration, substrate molar ratio, temperature and water activity were studied. Operational and storage stability of the enzyme were also assessed. The reaction followed Michaelis-Menton kinetics as observed from the relationship of initial rate of the reaction as a function of substrate concentration. It was found that the optimum substrate concentration was 0.15M palmitic acid and isopropyl alcohol in 1:1 stoichiometric ratio. Inhibition by excess of isopropyl alcohol has been identified. The optimum temperature for the esterification reaction was found to be around 50 degrees C. The activation energy of this process was determined to be 43.67 kJ/mol. The optimum water content was 0.50%. The reaction rates were measured in the absence of any significant external diffusional limitations. Since internal diffusional limitations could not be eliminated, the kinetics observed is only apparent.
  2. James V, Kee CY, Ong GY
    J Emerg Med, 2019 Apr;56(4):421-425.
    PMID: 30638645 DOI: 10.1016/j.jemermed.2018.12.015
    BACKGROUND: Point-of-care ultrasonography (POCUS) is increasingly used for both diagnostic and guided procedures. Increasingly, POCUS has been used for identification of pneumonia and to assist in the differentiation of pleural effusions, as well as to guide thoracentesis. As such, there is a need for training with ideally high-fidelity lung ultrasound phantoms to ensure ultrasound proficiency and procedural competency. Unfortunately, most commercial ultrasound phantoms remain expensive and may have limited fidelity.

    OBJECTIVE: Our aim was to create and describe a homemade, high-fidelity ultrasound phantom model for demonstrating pneumonia with pleural effusions for teaching purposes.

    DISCUSSION: An ultrasound phantom was constructed using a water-filled latex glove with a sliver of meat in it, covered over by a palm-sized piece of meat (skin and ribs are optional to increase ultrasonographic details and realism). This would appear like parapneumonic effusions with organized pneumonia under ultrasound examination. Creamer (or talc) can be added to the water in the glove to simulate empyema. The model can also be used to teach simple effusions and for ultrasound-guided thoracentesis and in clinical decision making.

    CONCLUSIONS: Easily prepared, homemade high-fidelity ultrasound phantom models for instructions on identification of pleural effusions and ultrasound-guided pleural tap of parapneumonic effusion were made.

  3. James V, Samuel J, Kee CY, Ong GY
    Ultrasound J, 2020 Dec 03;12(1):51.
    PMID: 33270182 DOI: 10.1186/s13089-020-00199-y
    BACKGROUND: The presence of intra-abdominal calcification in the pediatric population can be due to a wide range of conditions. Calcification in the abdomen can be seen in normal or abnormal anatomical structures. In some patients, abnormal calcification points towards the pathology; whereas in others, calcification itself is the pathology. After a thorough history and clinical examination, point-of-care ultrasound (POCUS) would complement the assessment of acute abdominal pain, based on the list of differentials generated as per the abdominal region. The main objective of this article is to review commonly encountered causes of intra-abdominal calcifications in the pediatric population and help in clinical decision-making in a Pediatric Emergency Department.

    CASE PRESENTATION: We describe a series of pediatric patients who presented to the Pediatric Emergency Department with acute abdominal pain, in whom point-of-care ultrasound helped expedite the diagnosis by identifying varying types of calcification and associated sonological findings. For children who present to the Pediatric Emergency Department with significant abdominal pain, a rapid distinction between emergencies and non-emergencies is vital to decrease morbidity and mortality.

    CONCLUSIONS: In a child presenting to the Pediatric Emergency Department with abdominal pain, POCUS and the findings of calcifications can narrow or expand the differential diagnosis when integrated with history and physical exam, to a specific anatomic structure. Integrating these findings with additional sonological findings of an underlying pathology might raise sufficient concerns in the emergency physicians to warrant further investigations for the patient in the form of a formal radiological ultrasound and assist in the patient's early disposition. The use of POCUS might also help to categorize the type of calcification to one of the four main categories of intra-abdominal calcifications, namely concretions, conduit wall calcification, cyst wall calcification, and solid mass-type calcification. POCUS used thoughtfully can give a diagnosis and expand differential diagnosis, reduce cognitive bias, and reduce physician mental load. By integrating the use of POCUS with the history and clinical findings, it will be possible to expedite the management in children who present to the Pediatric Emergency Department with acute abdominal pain.

  4. Tong CY, Kee CY, Honda K, Derek CJC
    Environ Res, 2023 Dec 15;239(Pt 2):117403.
    PMID: 37848079 DOI: 10.1016/j.envres.2023.117403
    Bio-coating, a recent and promising approach in attached microalgal cultivation systems, has garnered attention due to its efficiency in enhancing immobilized algal growth, particularly in submerged cultivation systems. However, when the cells are cultured on thin solid microporous substrates that physically separate them from the nutrient medium, it remains unclear whether the applied bio-coatings still have a significant impact on algal growth or the subsequent rates of algal organic matter (AOM) release. Therefore, this current work investigated the role of bio-coatings on the microalgal monoculture growth of one freshwater species, Chlorella vulgaris ESP 31, and one marine species, Cylindrotheca fusiformis on a hydrophilic substrate, polyvinylidene fluoride membrane in a permeated cultivation system. Wide range of bio-coating sources were adapted, with the result demonstrating that bacteria-derived coating promoted algal growth by as high as 140% when compared with the control group for both species. Interestingly, two distinct adaptation mechanisms were observed between the species, with only C. fusiformis demonstrating a positive correlation between cell growth and AOM productivity, particularly in its extracellularly bound fractions. It is worth noting that despite this specific fraction exhibiting the lowest content among all; it displayed significant relevance in terms of AOM productivity. High extracellular protein-to-polysaccharide ratio (>5.7 fold) quantified on bacterial intracellular exudate-coated membranes indirectly revealed an underlying symbiotic microalgal-bacterial interaction. This is the first study showing how bio-coating influenced AOM yield without any physical interaction between microalgae and bacteria. It further confirms the practical benefits of bio-coating in attached cultivation systems.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links