Displaying publications 1401 - 1420 of 1919 in total

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  1. Amy Suzana Abu Bakar, Norhafiza Razali, Mohammad Daniel Shafiq Hassan, Renu Agarwal
    MyJurnal
    Glaucoma is an optic neuropathy characterised by optic nerve degeneration associated with
    visual field defects. It remains the world’s number one cause of irreversible blindness and
    patients usually present at late stage of the disease since it is generally asymptomatic until
    severe. The disease is subdivided into primary and secondary with primary open-angle
    glaucoma (POAG) being the most common type. At present, lowering the intraocular pressure
    (IOP) remains the only proven efficient approach in delaying the onset or preventing the
    progression of the disease. Medical treatment with topical antiglaucoma agents is the
    treatment of choice in open angle glaucoma. The use of antiglaucoma drugs aims to reduce
    IOP by enhancing aqueous humour (AH) outflow, reducing AH production, or both. The choice
    to use any available treatment option should be carefully considered in an attempt to maximise
    benefits and reducing the risk of developing adverse drug reactions. This review highlights the
    six classes of ocular hypotensive agents currently in use for POAG treatment including
    prostaglandin analogues; -adrenergic receptor blockers; -2 adrenergic receptor stimulants;
    carbonic anhydrase inhibitors; muscarinic receptor stimulants; rho kinase inhibitors with
    regards to their mechanism/s of action and potential adverse drug reactions, and
    antiglaucoma fixed drug combinations.
    Matched MeSH terms: Intraocular Pressure
  2. Ammar Akram Kamarudin, Norazalina Saad, Nor Hafiza Sayuti, Nor Asma Ab. Razak, Norhaizan Mohd. Esa
    MyJurnal
    Introduction: Moringa oleifera Lam. is a miracle tree that has been widely utilised in folklore medicine due to its immense amount of phenolic constituents that could treat various ailments. Different techniques have been imple- mented to extract the phenolic but the parameters may not be optimised to further enhance the amount of phenolic extracted. Thus, the work aimed to enhance phenolic content and antioxidant activity of M. oleifera through RSM methodology, which is rapid and convenience. Methods: At first, antioxidant activity of different parts of M. oleifera (leaves, stem, pod and seed) were investigated. The plant part with the highest antioxidant activity was selected for the optimisation of extraction condition using RSM. In RSM, temperature (XA), extraction time (XB) and solid-liquid ratio (XC) were employed to study the effects on yield, total phenolics, flavonoids and antioxidant activity. Then, the optimum extraction condition obtained via RSM was utilised in LC-MS and HPLC analysis to determine the poten- tial bioactive constituents. Results: The leaves of M. oleifera displayed the highest antioxidant activity as compared to other plant parts. The optimum extraction condition obtained for the leaves extract was: temperature (XA): 82°C, extraction time (XB): 48 min and solid-liquid ratio (XC): 1:30 g/mL (w/v). Meanwhile, LC-MS revealed the presence of gallic acid, chlorogenic acid, quercetin, kaempferol and 3-O-glucoside kaempferol. HPLC analysis detected six compounds; gallic acid, epicatechin gallate, chlorogenic acid, myricetin, quercetin and kaempferol. Conclusion: The optimisation are promising to improve yield and antioxidant activity in M. oleifera as compared to non-conven- tional extractions.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  3. Mohd Amnan MA, Pua TL, Lau SE, Tan BC, Yamaguchi H, Hitachi K, et al.
    PeerJ, 2021;9:e10879.
    PMID: 33614294 DOI: 10.7717/peerj.10879
    Drought is one of the severe environmental stresses threatening agriculture around the globe. Nitric oxide plays diverse roles in plant growth and defensive responses. Despite a few studies supporting the role of nitric oxide in plants under drought responses, little is known about its pivotal molecular amendment in the regulation of stress signaling. In this study, a label-free nano-liquid chromatography-mass spectrometry approach was used to determine the effects of sodium nitroprusside (SNP) on polyethylene glycol (PEG)-induced osmotic stress in banana roots. Plant treatment with SNP improved plant growth and reduced the percentage of yellow leaves. A total of 30 and 90 proteins were differentially identified in PEG+SNP against PEG and PEG+SNP against the control, respectively. The majority of proteins differing between them were related to carbohydrate and energy metabolisms. Antioxidant enzyme activities, such as superoxide dismutase and ascorbate peroxidase, decreased in SNP-treated banana roots compared to PEG-treated banana. These results suggest that the nitric oxide-induced osmotic stress tolerance could be associated with improved carbohydrate and energy metabolism capability in higher plants.
    Matched MeSH terms: Osmotic Pressure
  4. Tabassam, Q., Mehmood, T., Anwar, F., Saari, N., Qadir, R.
    MyJurnal
    The present work studies the profiling of phenolic bioactive and in vitro biological (anticancer, antioxidant, and antimicrobial) activities of different solvent extracts from Withania
    somnifera fruit. Anticancer activity was performed using potato-disc assay and Agrobacterium tumefaciens. While antibacterial and antifungal evaluation was done by using disc diffusion method against bacterial (Staphylococcus aureus, S. epidermidis, Escherichia coli, and
    Klebsiella pneumonia) and fungal (Aspergillus flavus and Fusarium oxysporum) strains.
    Among different extraction solvents used, n-hexane extract exhibited the highest inhibition of
    tumour initiation (64%), whereas ethyl acetate (15%) was the lowest by using potato-disc
    assay. Highest total phenolic and total flavonoid contents were noted for methanolic (69.10
    GAE mg/g DW%) and n-hexane (29.45 CE mg/g DW%) extracts, respectively. For antioxidant potential, 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging (IC50) and reducing power EC50 were noted to be superior (0.6 and 2.0 mg/mL, respectively) for n-hexane
    extract. All the tested extracts showed considerable antibacterial and antifungal activity with
    the highest growth inhibition zones for K. pneumoniae (31.70 mm) and A. flavus (27.09 mm)
    were shown by n-hexane extract. High Performance Liquid Chromatographic (HPLC) analysis of individual phenolics (gallic acid, 2,288.48 mg/kg) indicated the highest contents of these
    compounds in n-hexane extract, which might explain the potent biological activities of this
    extract. Our findings revealed that the bioactive present in the tested fruit had significant
    potential as anticancer, antibacterial, and antifungal agents. Further studies are needed to
    elucidate the mechanism of actions of isolated bioactive against specific diseases such as
    cancer, especially in the case of n-hexane fraction.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. Norfazilah Ahmad, Santhna Letchmi Panduragan, Yee,San Khor, Kalaiarasan Gemini, Nur Atikah Bahrin, Nur Husnina Azhar, et al.
    Borneo Epidemiology Journal, 2020;1(1):35-45.
    MyJurnal
    Strategising, which is an effective workplace intervention to curb cardiovascular disease (CVD), requires understanding of the CVD risk related to a specific working population. The Framingham Risk Score (FRS) is widely used in predicting the ten-year CVD risk of various working populations. This study aimed to use FRS to determine the ten-year CVD risk amongst workers in a tertiary healthcare setting and its associated factors. A cross-sectional study was conducted on workers who participated in the special health check programme at the staff clinic of a tertiary healthcare institution in Kuala Lumpur, Malaysia. A set of data sheets was used to retrieve the workers’ sociodemographic and CVD risk information. The prevalence of high, moderate and low ten-year CVD risk was 12.8%, 20.0% and 67.2%, respectively. Workers in the high-risk group were older [mean age: 54.81 (standard deviation, 5.72) years], male (44%), smokers (72.7%) and having hyperglycaemia (46.7%) and hypertriglyceridemia [median triglycerides: 1.75 (interquartile range, 1.45) mmol/L]. Diastolic blood pressure (aOR 1.07, 95% CI: 1.01,1.14), hyperglycaemia (aOR 8.80, 95% CI: 1.92,40.36) and hypertriglyceridemia (aOR 4.45, 95% CI: 1.78,11.09) were significantly associated with high ten-year CVD risk. Diastolic blood pressure (aOR 1.08, 95% CI: 1.03,1.13) and hypertriglyceridemia (aOR 2.51, 95% CI: 1.12-5.61) were significantly associated with moderate ten-year CVD risk. The prevalence of high and moderate ten-year CVD risk was relatively high. Amongst the workers in the high-risk group, they were older, male, smokers and with high fasting blood sugar and triglyceride. Understanding the ten-year CVD risk and its associated factors could be used to plan periodic workplace health assessment and monitor to prevent CVD
    Matched MeSH terms: Blood Pressure
  6. Tan SY, Md Din N, Mohd Khialdin S, Wan Abdul Halim WH, Tang SF
    Cureus, 2021 Feb 12;13(2):e13320.
    PMID: 33738163 DOI: 10.7759/cureus.13320
    The hazy corneal donor-recipient interface after corneal transplant may cause difficulties when implanting the XEN gel stent via ab-interno approach. We aim to describe XEN gel stent implantation via ab-externo approach in refractory steroid-induced glaucoma after corneal lamellar keratoplasty. Under local anaesthesia, the XEN injector needle was inserted 7 mm behind the limbus with the bevel facing up, directly beneath the conjunctiva and advanced to the marked 2.5 mm scleral entry wound. The needle then pierced the sclera until the needle tip was just visible in the anterior chamber (AC). The slider was pushed until the tip of the XEN stent was seen in the AC. The needle was slowly withdrawn while still pushing the slider to complete stent deployment. Subconjunctival Mitomycin C 0.01% (30 µg/0.3 mL) was then injected posterior to the bleb. Three eyes of three patients with steroid-induced glaucoma after lamellar keratoplasty underwent XEN gel stent implantation via ab-externo approach placed at the superotemporal quadrant. Pre-operatively, all patients had uncontrolled IOP between 30-45 mmHg despite maximum medications and selective laser trabeculoplasty. After XEN gel stent implantation, IOP ranged between 10-17 mmHg with one or two topical antiglaucoma at 12 months. Complications include hypotony maculopathy, stent migration and hyphaema, all of which were successfully managed. Corneal graft remained clear at 12 months. XEN gel stent implantation via ab-externo approach is able to achieve good intraocular pressure (IOP) control without compromising cornea graft in patients with steroid-induced glaucoma after lamellar keratoplasty at 12 months.
    Matched MeSH terms: Intraocular Pressure
  7. Khairul Anwar Zarkasi, Vennila Gopal, Sadia Choudhury Shimmi, Anne Lolita Miranda, Wan Salman Wan Saudi, Caroline Sunggip, et al.
    MyJurnal
    Obesity is a known risk factor for non-communicable diseases, including hypertension and diabetes mellitus, with Malaysia having the highest prevalence of obesity among Southeast Asian countries. Additionally, the delivery of medical services to the rural communities remains challenging despite efforts to increase accessibilities to the healthcare facilities. Therefore, regular health screening programmes specifically aiming at these communities are necessary for early diagnosis and intervention to prevent complications while improving the patients’ quality of life. A health screening programme was conducted in a sub-district of Kota Kinabalu, Sabah, Malaysia, where 50 participants were examined for general obesity based on body mass index (BMI) together with central obesity according to waist circumference (WC) and waist-to-hip ratio (WHR). Bioelectrical impedance analysis was performed to estimate body fat percentage (fat%) and body fat mass, along with the measurement of systolic blood pressure (SBP), diastolic blood pressure (DBP), and capillary blood glucose. The median age of the participants was 39.50 years. The prevalence of general obesity, central obesity based on WC and WHR, hypertension, and hyperglycaemia was 28%, 78%, 74%, 24%, and 20%, respectively. Both fat% and fat mass had positive correlations to the BMI (fat%: r = 0.656, p = 0.001; fat mass: r = 0.868, p = 0.001) and WC (fat%: r = 0.505, p = 0.001; fat mass: r = 0.761, p = 0.001). DBP had positive correlations with the BMI (r = 0.390, p = 0.005), WC (r = 0.467, p = 0.001), and WHR (r = 0.331, p = 0.019), while SBP had a positive correlation only with WC (r = 0.341, p = 0.015). Conversely, capillary blood glucose had no significant correlation with either BMI, WC, or WHR. The higher prevalence of central obesity among participants of the health screening program compared to the national level should raise concern among the healthcare providers regarding the future risk for hypertension and hyperglycaemia in this community
    Matched MeSH terms: Blood Pressure
  8. Sheikh HM, Reshi NA
    Trop Biomed, 2020 Sep 01;37(3):812-821.
    PMID: 33612794 DOI: 10.47665/tb.37.3.812
    The bioactivity of R. nasutus leaf extracts was assessed on Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogenes, Vibrio parahaemolyticus, Enterobacter aerogenes, Proteus mirabilis, and Klebsiella pneumoniae. Crude chloroform, petroleum ether, ethyl acetate, ethanol and methanol extracts were screened by disc diffusion method. Promising crude extract was further subjected to the column fractionation followed by the screening of the antibacterial activity of individual fractions. Biologically active pure fraction was subjected to the advanced analytical studies like HPLC, LC-MS, IR and NMR for characterisation of the bioactive compound. Ethanolic extract exhibited the maximum antibacterial activity against Klebsiella pneumoniae with the maximum of 35±0.42 mm zone of inhibition. The biologically potent column fraction from ethanol extract with 40±0.42 mm zone of inhibition upon subject to the HPLC, LC-MS, IR and NMR revealed that the active compound is rhinacanthin-C, a naphthoquinone.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. Fayez A Almabhouh, Faizatul Isyraqiah Ahmad Muhammad, Hisham Ibrahim, Harbindarjeet Singh
    MyJurnal
    Leptin, a 16 kDa protein and a product of the ob/ob gene, has a tertiary structure similar to that
    of a cytokine. It is primarily secreted by white adipose tissue and its levels in the blood correlate
    positively with percentage body fat. Leptin was first identified in 1994 as a major factor that
    regulated food intake and energy balance. Leptin in the circulation exists either as a free
    monomeric hormone or bound to its soluble receptor. Its serum levels usually range from 0.5 to
    37.7 ng/ml in males and 2.0 to 45.2 ng/ml in females. The half-life of leptin is between 20 - 30
    minutes and it is eliminated mainly by the kidneys. However, research over the last 25 years
    has revealed numerous other physiological roles for leptin, including roles in inflammation,
    immune function, neuro-endocrine function, bone metabolism, blood pressure regulation and
    sexual maturation. Most of these roles have been identified from studies on leptin deficient
    rodents. Apart from energy balance and sexual maturation, where its role is direct and obvious,
    its actions on the rest of the other systems are permissive. Actions of leptin are both centrally
    and peripherally mediated involving receptors that are widely distributed in the body. Six leptin
    receptor isoforms, belonging to the class 1 cytokine receptor family, have been identified.
    These receptors are products of the OBR gene. The cellular actions of leptin are mediated
    through any one of five different signalling pathways that include the JAK-STAT, PI3K, MAPK,
    AMPK, and the mTOR signalling pathways.
    Matched MeSH terms: Blood Pressure
  10. Nurul-Alia Samiun, Barakatun-Nisak Mohd Yusof, Irmi Zarina Ismail, Norfarhana Mohd Anuar, Winnie Chee Siew Swee
    MyJurnal
    Introduction: Optimal nutritional status is of utmost importance not only for foetal
    development but also to maintain normoglycemia in women with gestational diabetes mellitus
    (GDM). This cross-sectional study described the nutritional status of women with GDM and
    explored whether self-reported nutrition education (NEd) exposure before a GDM diagnosis
    would be able to promote better nutrition status. Methods: GDM women (n= 60; age= 31.6 ±
    5.0 years) diagnosed between 13th and 28th week of gestation participated in the study. We
    assessed nutritional status that included anthropometric and blood pressure assessments,
    biochemical data, and dietary intake. The respondents self-reported their NEd exposure before
    a GDM diagnosis was made. Results: The pre-pregnancy BMI of the participants was 27.9 ±
    6.8 kg/m2
    , which was categorised as overweight. Total (4.3 ± 5.6 kg) and rate (0.2 ± 0.3
    kg/week) of gestational weight gain were within the recommendations. Glycemic parameters
    and blood pressure were also within the normal range. Nevertheless, they had high intakes of
    fat (35.5%) and sugar (14.4%) proportionate to their energy intake. They did not meet the
    recommended nutrient intakes for fibre, calcium, and iron. Only 28.3% of women had prior
    NEd exposure. Among them, almost all (94.1%) had recurrent GDM. Those with NEd
    exposure had lower pre-prandial blood glucose profiles, systolic blood pressure, and
    proportion of protein intake from energy than those without (p< 0.05). Conclusions:
    Suboptimal maternal nutritional status and low exposure to NEd are evident in women with
    GDM. Those with self-reported NEd exposure had better parameters of nutritional status. The
    findings recognised the need of having proper nutrition education for women who are at high
    risk of GDM since at early pregnancy.
    Matched MeSH terms: Blood Pressure
  11. Al-Jaal B, Latiff A, Salama S, Hussain HM, Al-Thani NA, Al-Naimi N, et al.
    Toxins (Basel), 2021 04 08;13(4).
    PMID: 33917988 DOI: 10.3390/toxins13040267
    Mycotoxins are naturally occurring food toxins worldwide that can cause serious health effects. The measurement of mycotoxin biomarkers in biological fluids is needed to assess individuals' exposure. The aim of this study was to investigate the incidence of mycotoxins in the Qatari population. Serum samples from 412 adults and urinary samples from 559 adults were analyzed for the presence of mycotoxin biomarkers. Multimycotoxin approaches have been applied, using liquid chromatography mass spectrometry methods. Samples were further analyzed for the oxidative stress markers and compared with regard to the incidence of mycotoxins. The presence of mycotoxins was identified in 37% of serum samples and in less than 20% of urine samples. It was found that 88% of positive of the samples were positive for only one mycotoxin, while 12% of positive samples had two or more mycotoxins. Trichothecenes and zearalenone metabolites were most commonly detected mycotoxins, followed by aflatoxins, roquefortine C and mycophenolic acid. The presence of mycotoxins was found to positively correlate with oxidative stress markers. The obtained results illustrate the importance of mycotoxin biomonitoring studies in humans and the need to elucidate the underlying mechanisms of mycotoxin-induced toxicity.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  12. Tan JWC, Sim D, Ako J, Almahmeed W, Cooper ME, Dalal JJ, et al.
    Eur Cardiol, 2021 Feb;16:e14.
    PMID: 33976709 DOI: 10.15420/ecr.2020.52
    The Asian Pacific Society of Cardiology convened a consensus statement panel for optimising cardiovascular (CV) outcomes in type 2 diabetes, and reviewed the current literature. Relevant articles were appraised using the Grading of Recommendations, Assessment, Development and Evaluation system, and consensus statements were developed in two meetings and were confirmed through online voting. The consensus statements indicated that lifestyle interventions must be emphasised for patients with prediabetes, and optimal glucose control should be encouraged when possible. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are recommended for patients with chronic kidney disease with adequate renal function, and for patients with heart failure with reduced ejection fraction. In addition to SGLT2i, glucagon-like peptide-1 receptor agonists are recommended for patients at high risk of CV events. A blood pressure target below 140/90 mmHg is generally recommended for patients with type 2 diabetes. Antiplatelet therapy is recommended for secondary prevention in patients with atherosclerotic CV disease.
    Matched MeSH terms: Blood Pressure
  13. Hatta, S.
    Medicine & Health, 2020;15(1):1-4.
    MyJurnal
    Psychophysiological effect associated to an event is inseparable with regard to the human’s mental health (Celik 2010; Cannon 1987; Roxo et al. 2011; Laird & Lacasse 2014). The manifestation of psychophysiological phenomenon in relation to an event has been observed during pre-modern era and inspired physician like Avicenna from the influence of the great thinker of Aristotle and Plato. Avicenna or IbnuSina, the Persian-born philosopher and physician from the Greco-Islamic era, has made his standpoint on the clinical importance of pulsology (Celik 2010). In his earlier concepts on pulse patterns, it was found that pulse would rise when he or she is anticipating an event, especially if an event is meaningful and related to him or her. Avicenna documented in dealing with such events, the psychophysiological changes that were observed, i.e. increased pulse from normal pulse. For example, a man who is approaching a house with a lady that he loved, started to experience tachycardia and palpitation. Sphygmology, a study of pulses is based on the contribution by Ibnu-Sina (Zarshenas et al. 2013). It is a relatively simple, practical and inexpensive means, having a significant diagnosis yield (Zarshenas et al. 2013). It has been recognised through the history of medicine, over the centuries, that we have a better understanding on the fundamental concept of coping with stress by observing our own pulses. Using this modest physiological approach, it has contributed to the modern way in dealing with distressed situation-the psychophysiology of biofeedback therapy and instilling the Buddhist teaching of mindfulness. For example in the former, biofeedback is a simple way of overcoming stress. Biofeedback therapy is a method that trains people to enhance their health by regulating certain bodily processes that normally happen involuntarily (Abgrall-Barbry & Consoli 2006). Once we are in a stressful state, our pulse and blood pressure will increase. Meditating, or self-dialogueand telling our brain that, “I am in control and can dictate my pulse from the highest to lowest possible beat,” can be helpful in dealing with our stress level via higher mental function coordination. Indeed, regulation of basic physiological phenomena and psychological input-“calming the mind” has both anatomical and neurophysiological explanation via the reticular activating system and thalamic integration. Understanding a simple way in managing with stress, especially during the difficult and stressful time can be gratifying and rewarding. This is especially true when it comes to inconveniences, hassle and problems due to coronavirus disease 2019 (COVID-19) pandemic, and during the movement control order (MCO).
    Matched MeSH terms: Blood Pressure
  14. Zamram QAZM, Mohsin HF, Mohamad MM, Nor Hazalin NAM, Hamid KA
    Curr Drug Deliv, 2021 Apr 18.
    PMID: 33874872 DOI: 10.2174/1567201818666210419114809
    AIM: Formulating topical products for skin delivery has always been a challenge for pharmaceutical scientists to fulfil good formulation criteria. Despite the challenges, gel-based drug delivery offers some advantages such that it is non-invasive, painless, avoidance of the first-pass metabolism and has satisfactory patient compliance.

    OBJECTIVES: In this study, Chromolaena odorata gel and quercetin gel (bioactive flavonoid compound) were successfully formulated and compared with placebo and conventional wound aid gel. The chromatographic profilling was conducted to screen the presence of phytoconstituents. Subsequently, all formulated gels were subjected to physical characteristic and stability study.

    METHODS: Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) of C.odorata methanolic leaves extract shows a distinct compound separation at retention time 8.4min to 34.8 min at 254nm. All gels were characterised by evaluating their rheological properties including storage modulus, loss modulus and plastic viscosity. Besides, texture analysis was performed to measure the gels' firmness, consistency, cohesiveness, and viscosity index.

    RESULTS: From the observation, C. odorata gel demonstrated better spreadability as compared to the other gels, which acquired less work and favourable to be applied onto the skin. Moreover, C. odorata gel showed no changes in organoleptic properties and proven to be stable after 30 days of accelerated stability study at 40°C ± 2°C with relative humidity (RH) of 75%± 5%.

    CONCLUSION: C. odorata gel has shown to be stable, reflecting the combination of materials used in the formulation, which did not degrade throughout the study. This work suggests the potential of this gel as a vehicle to deliver the active ingredients of C. odorata to the skin, which can be further explored as a topical application in antimicrobial wound management or other skin diseases study.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  15. Eshraghi A, Maroufi N, Sanjari MA, Saeedi H, Keyhani MR, Gholizadeh H, et al.
    Prosthet Orthot Int, 2013 Feb;37(1):76-84.
    PMID: 22751219 DOI: 10.1177/0309364612448805
    Biomechanical factors, such as spinal deformities can result in balance control disorders.
    Matched MeSH terms: Pressure
  16. Siddiqui MF, Sakinah M, Singh L, Zularisam AW
    J Biotechnol, 2012 Oct 31;161(3):190-7.
    PMID: 22796090 DOI: 10.1016/j.jbiotec.2012.06.029
    Exploring novel biological anti-quorum sensing (QS) agents to control membrane biofouling is of great worth in order to allow sustainable performance of membrane bioreactors (MBRs) for wastewater treatment. In recent studies, QS inhibitors have provided evidence of alternative route to control membrane biofouling. This study investigated the role of Piper betle extract (PBE) as an anti-QS agent to mitigate membrane biofouling. Results demonstrated the occurrence of the N-acyl-homoserine-lactone (AHL) autoinducers (AIs), correlate QS activity and membrane biofouling mitigation. The AIs production in bioreactor was confirmed using an indicator strain Agrobacterium tumefaciens (NTL4) harboring plasmid pZLR4. Moreover, three different AHLs were found in biocake using thin layer chromatographic analysis. An increase in extracellular polymeric substances (EPS) and transmembrane pressure (TMP) was observed with AHL activity of the biocake during continuous MBR operation, which shows that membrane biofouling was in close relationship with QS activity. PBE was verified to mitigate membrane biofouling via inhibiting AIs production. SEM analysis further confirmed the effect of PBE on EPS and biofilm formation. These results exhibited that PBE could be a novel agent to target AIs for mitigation of membrane biofouling. Further work can be carried out to purify the active compound of Piper betle extract to target the QS to mitigate membrane biofouling.
    Matched MeSH terms: Pressure
  17. Ali S, Osman NA, Mortaza N, Eshraghi A, Gholizadeh H, Wan Abas WA
    Clin Biomech (Bristol), 2012 Nov;27(9):943-8.
    PMID: 22795863 DOI: 10.1016/j.clinbiomech.2012.06.004
    The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. Liners provide a comfortable interface by adding a soft cushion between the residual limb and the socket. The Dermo and the Seal-In X5 liner are two new interface systems and, due to their relative infancy, very little are known about their effect on patient satisfaction. The aim of this study was to compare the interface pressure with these two liners and their effect on patient satisfaction.
    Matched MeSH terms: Pressure
  18. Moo EK, Herzog W, Han SK, Abu Osman NA, Pingguan-Murphy B, Federico S
    Biomech Model Mechanobiol, 2012 Sep;11(7):983-93.
    PMID: 22234779 DOI: 10.1007/s10237-011-0367-2
    Experimental findings indicate that in-situ chondrocytes die readily following impact loading, but remain essentially unaffected at low (non-impact) strain rates. This study was aimed at identifying possible causes for cell death in impact loading by quantifying chondrocyte mechanics when cartilage was subjected to a 5% nominal tissue strain at different strain rates. Multi-scale modelling techniques were used to simulate cartilage tissue and the corresponding chondrocytes residing in the tissue. Chondrocytes were modelled by accounting for the cell membrane, pericellular matrix and pericellular capsule. The results suggest that cell deformations, cell fluid pressures and fluid flow velocity through cells are highest at the highest (impact) strain rate, but they do not reach damaging levels. Tangential strain rates of the cell membrane were highest at the highest strain rate and were observed primarily in superficial tissue cells. Since cell death following impact loading occurs primarily in superficial zone cells, we speculate that cell death in impact loading is caused by the high tangential strain rates in the membrane of superficial zone cells causing membrane rupture and loss of cell content and integrity.
    Matched MeSH terms: Pressure
  19. Lee TP, Saad B, Khayoon WS, Salleh B
    Talanta, 2012 Jan 15;88:129-35.
    PMID: 22265478 DOI: 10.1016/j.talanta.2011.10.021
    A simple, environmental friendly and selective sample preparation technique employing porous membrane protected micro-solid phase extraction (μ-SPE) loaded with molecularly imprinted polymer (MIP) for the determination of ochratoxin A (OTA) is described. After the extraction, the analyte was desorbed using ultrasonication and was analyzed using high performance liquid chromatography. Under the optimized conditions, the detection limits of OTA for coffee, grape juice and urine were 0.06 ng g(-1), 0.02 and 0.02 ng mL(-1), respectively while the quantification limits were 0.19 ng g(-1), 0.06 and 0.08 ng mL(-1), respectively. The recoveries of OTA from coffee spiked at 1, 25 and 50 ng g(-1), grape juice and urine samples at 1, 25 and 50 ng mL(-1) ranged from 90.6 to 101.5%. The proposed method was applied to thirty-eight samples of coffee, grape juice and urine and the presence of OTA was found in eighteen samples. The levels found, however, were all below the legal limits.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Lim E, Dokos S, Salamonsen RF, Rosenfeldt FL, Ayre PJ, Lovell NH
    Artif Organs, 2012 May;36(5):E125-37.
    PMID: 22489771 DOI: 10.1111/j.1525-1594.2012.01448.x
    Numerical models, able to simulate the response of the human cardiovascular system (CVS) in the presence of an implantable rotary blood pump (IRBP), have been widely used as a predictive tool to investigate the interaction between the CVS and the IRBP under various operating conditions. The present study investigates the effect of alterations in the model parameter values, that is, cardiac contractility, systemic vascular resistance, and total blood volume on the efficiency of rotary pump assistance, using an optimized dynamic heart-pump interaction model previously developed in our laboratory based on animal experimental measurements obtained from five canines. The effect of mean pump speed and the circulatory perturbations on left and right ventricular pressure volume loops, mean aortic pressure, mean cardiac output, pump assistance ratio, and pump flow pulsatility from both the greyhound experiments and model simulations are demonstrated. Furthermore, the applicability of some of the previously proposed control parameters, that is, pulsatility index (PI), gradient of PI with respect to pump speed, pump differential pressure, and aortic pressure are discussed based on our observations from experimental and simulation results. It was found that previously proposed control strategies were not able to perform well under highly varying circulatory conditions. Among these, control algorithms which rely on the left ventricular filling pressure appear to be the most robust as they emulate the Frank-Starling mechanism of the heart.
    Matched MeSH terms: Pressure
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