Displaying publications 41 - 60 of 314 in total

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  1. Development of a predictive model for work-relatedness of MSDs among semiconductor back-end workers
    Ling CF, Radin Umar RZ, Ahmad N
    Int J Occup Saf Ergon, 2020 Dec 29.
    PMID: 33096963 DOI: 10.1080/10803548.2020.1840116
    Objective. Limited models are available to predict work-relatedness of musculoskeletal disorders (MSDs) among semiconductor back-end workers. This study aims to develop a model to predict the MSDs development among back-end workers. Method. Potential MSD risk factors were extracted from 277 work compensation investigation reports conducted between 2011-2019. Binary logistic regression approach was used to determine significant predictors. Results. Significant predictors (p 
  2. Effect of Synthesis Temperature on the Morphologies, Optical and Electrical Properties of MgO Nanostructures
    Sagadevan S, Venilla S, Marlinda AR, Johan MR, Wahab YA, Zakaria R, et al.
    J Nanosci Nanotechnol, 2020 Apr 01;20(4):2488-2494.
    PMID: 31492266 DOI: 10.1166/jnn.2020.17185
    Herein, we report the effect of synthesis temperature on the morphologies, optical and electronic properties of magnesium oxide (MgO) nanostructures. The MgO nanostructures were synthesized at different temperatures, i.e., 100 °C, 300 °C, and 600 °C by simple chemical reaction process and their morphology, particle size, optical, and electrical properties were examined by different techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV-Vis. spectroscopy. The morphological investigations revealed that various morphologies of MgO nanostructures, i.e., nanoparticles, nanosheet networks, and nanoneedles were synthesized at 100 °C, 300 °C, and 600 °C. The XRD results confirmed that with increasing the synthesis temperature, the crystallinity of the synthesized nanostructures increases. Further, the dielectric properties and AC conductivity at various frequencies for MgO nanostructures were studied which revealed that the dielectric losses decrease with increase in frequency and temperature. In addition, the observed band gap decreases from 4.89 eV to 4.438 eV (100 °C to 600 °C) representing its increase in the conductivity.
  3. Visible-Light Driven Effective Photocatalytic Degradation of Methylene Blue Dye Using Perforated Curly Zn0.1Ni0.9O Nanosheets
    Karthikeyan V, Gnanamoorthy G, Varun Prasath P, Narayanan V, Sagadevan S, Umar A, et al.
    J Nanosci Nanotechnol, 2020 Sep 01;20(9):5759-5764.
    PMID: 32331175 DOI: 10.1166/jnn.2020.17898
    Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.
  4. Reclamation of Hexavalent Chromium from Electroplating Effluents by Electroextraction
    Revathi M, Sivagaami Sundari G, Ahmed Basha C, Alam M, Sagadevan S, Ahmad N
    J Nanosci Nanotechnol, 2020 10 01;20(10):6547-6554.
    PMID: 32385012 DOI: 10.1166/jnn.2020.18562
    This investigation aims at the reclamation of Cr(VI) from synthetic electroplating industrial effluent by electroextraction process namely electrochemical ion exchange (EIX). An electrochemical ion exchange reactor of desired dimensions was fabricated with the help of ion-permeable membranes, stainless steel cathode and PbO₂ coated Ti expanded mesh anode. The performance of the reactor was studied in batch recirculation mode, continuous flow mode at different experimental conditions. The influence of various experimental factors, for instance, initial metal ion concentration (20, 300, 1000 mg/L of Cr(VI)), applied voltages (2.5 V, 5 V, 7.5 V, 10 V) and flow rates of the process stream (2, 4, 6, 8, 10, 12 and 14 ml/min) on removal/reclamation efficiency was deliberated. For comparison purposes, an electrodialysis process was conducted at the same optimal conditions. It was found that the EIX process with three compartments has more removal efficiency at optimum experimental conditions than the electrodialysis process. The continuous flow process of the reactor with 300 mg/L of Cr(VI) as inlet concentration has studied to predict the breakeven point of the reactor. It was noted that Cr(VI) ion concentration in the treated wastewater is almost zero up to the discharge of 20 liters of treated rinse water.
  5. Eucalyptus Concoction Mediated Synthesis of Gold Nanoparticles and Its Bioactive Role Explored via Antimicrobial and Cytotoxic Studies
    Muthiah B, Muthukrishnan L, Anita Lett J, Sagadevan S, Kesavan S, Vennila S, et al.
    J Nanosci Nanotechnol, 2020 10 01;20(10):6326-6333.
    PMID: 32384982 DOI: 10.1166/jnn.2020.17897
    Biosynthesis of nanoparticles has now become a novel trend in addressing some of the environmental issues by adopting eco-friendly approaches in manoeuvring nanoparticles for various applications. Plants and micro-organisms have been the potential sources of the biological mode of synthesizing nanoparticles as part of their bioremediation process. This principle has been harnessed for synthesizing nanoparticles either extra or intracellularly. In this line of phyto-mediated synthesis, eucalyptus buds have been used for synthesizing gold nanoparticles (Au NPs) under optimized laboratory conditions. The UV-visible spectrum of the Au NPs showed typical surface plasmon resonance at 550 nm (λmax) with a crystalline phase measuring <100 nm in size and monodispersed as revealed from XRD, FESEM, and AFM analyses. The biological role of phytochemical concoction in reducing and stabilizing the Au NPs was clearly identified from FT-IR studies. The antimicrobial effect of the Au NPs against clinically important pathogens viz. Staphylococcus sp., Pseudomonas sp., Bacillus sp. and E. coli determined using the disk diffusion method showed no significant antibacterial effect at all concentrations. Cytotoxicity studies were carried using Vero and HEp-2 cell lines and the 50% inhibition concentration (IC50) was determined to be 1.25 mg and 0.625 mg/mL respectively. Au NPs with potential antimicrobial and anti-proliferative effects could found profound implications in the field of nanomedicine once the toxicity in vivo has been investigated.
  6. Fulltext Factors influencing childhood immunisation uptake in Africa: a systematic review
    Galadima AN, Zulkefli NAM, Said SM, Ahmad N
    BMC Public Health, 2021 07 28;21(1):1475.
    PMID: 34320942 DOI: 10.1186/s12889-021-11466-5
    BACKGROUND: Vaccine preventable diseases are still the most common cause of childhood mortality, with an estimated 3 million deaths every year, mainly in Africa and Asia. An estimate of 29% deaths among children aged 1-59 months were due to vaccine preventable diseases. Despite the benefits of childhood immunisation, routine vaccination coverage for all recommended Expanded Programme on Immunization vaccines has remained poor in some African countries, such as Nigeria (31%), Ethiopia (43%), Uganda (55%) and Ghana (57%). The aim of this study is to collate evidence on the factors that influence childhood immunisation uptake in Africa, as well as to provide evidence for future researchers in developing, implementing and evaluating intervention among African populations which will improve childhood immunisation uptake.

    METHODS: We conducted a systematic review of articles on the factors influencing under-five childhood immunisation uptake in Africa. This was achieved by using various keywords and searching multiple databases (Medline, PubMed, CINAHL and Psychology & Behavioral Sciences Collection) dating back from inception to 2020.

    RESULTS: Out of 18,708 recorded citations retrieved, 10,396 titles were filtered and 324 titles remained. These 324 abstracts were screened leading to 51 included studies. Statistically significant factors found to influence childhood immunisation uptake were classified into modifiable and non-modifiable factors and were further categorised into different groups based on relevance. The modifiable factors include obstetric factors, maternal knowledge, maternal attitude, self-efficacy and maternal outcome expectation, whereas non-modifiable factors were sociodemographic factors of parent and child, logistic and administration factors.

    CONCLUSION: Different factors were found to influence under-five childhood immunisation uptake among parents in Africa. Immunisation health education intervention among pregnant women, focusing on the significant findings from this systematic review, would hopefully improve childhood immunisation uptake in African countries with poor coverage rates.

  7. Fulltext Herpetofauna of gunung panti forest reserve, johor, peninsular malaysia
    Onn CK, Grismer LL, Matsui M, Nishikawa K, Wood PL, Grismer JL, et al.
    Trop Life Sci Res, 2010 Aug;21(1):71-82.
    PMID: 24575191 MyJurnal
    A survey was carried out at Gunung Panti Forest Reserve, Johor from 3-7 August 2006, 2-5 June 2008, and 28-31 July 2008 to inventory the herpetofauna therein. An updated checklist for the area which incorporates findings from previous studies is provided. In total, 37 species of frogs, 1 turtle, 27 lizards, and 11 snakes have been recorded from Gunung Panti Forest Reserve, Johor.
  8. Fulltext Preliminary checklist of the herpetofauna of Pulau Besar, Melaka, Malaysia
    Chan KO, Grismer LL, Wood, PL, Grismer JL, Ahmad N
    Trop Life Sci Res, 2009;20(1):-.
    MyJurnal
    A herpetological survey was conducted at Pulau Besar, Melaka from 10 to 12 June 2008, resulting in the discovery of five species of amphibians, nine species of lizards (including one new species of the gekkonid Cyrtodactylus) and one snake species. This report constitutes the first checklist of the herpetofauna of Pulau Besar and the Water Islands Archipelago.
  9. Fulltext Molecular insights of co-trimoxazole resistance genes in Haemophilus influenzae isolated in Malaysia
    Mohd-Zain Z, Kamsani NH, Ahmad N
    Trop Biomed, 2013 Dec;30(4):584-90.
    PMID: 24522126 MyJurnal
    In the last few decades, co-trimoxazole (SXT), an antibacterial combination of trimethoprim and sulfamethoxazole, has been used for treatment of upper respiratory tract infection due to Haemophilus influenzae. The usage of this antibiotic has become less important due to emergence of SXT-resistant strains worldwide. Most reports associate SXT resistance to the presence of variants of dihydrofolate reductase (DHFR) dfrA genes which are responsible for trimethoprim resistance; while the sulfamethoxazole (SMX) resistance are due to sulfonamide (SUL) genes sul1 and sul2 and/or mutation in the chromosomal (folP) gene encoding dihydropteroate synthetase (DHPS). This study aims to detect and analyse the genes that are involved in SXT resistance in H. influenzae strains that were isolated in Malaysia. Primers targeting for variants of dfrA, fol and sul genes were used to amplify the genes in nine SXT-resistant strains. The products of amplification were sequenced and multiple alignments of the assembled sequences of the local strains were compared to the sequences of other H. influenzae strains in the Genbank. Of the five variants of the dhfA genes, dfrA1 was detected in three out of the nine strains. In contrast to intermediate strains, at least one variant of folP genes was detected in the resistant strains. Multiple nucleotide alignment of this gene revealed that strain H152 was genetically different from the others due to a 15-bp nucleotide insert in folP gene. The sequence of the insert was similar to the insert in folP of H. influenzae strain A12, a strain isolated in United Kingdom. None of the strains had sul1 gene but sul2 gene was detected in four strains. Preliminary study on the limited number of samples shows that the TMP resistance was attributed to mainly to dfrA1 and the SMX was due to folP genes. Presence of sul2 in addition to folP in seven strains apparently had increased their level of resistance. A strain that lacked sul1 or sul2 gene, its resistance to sulfonamide was attributed to a 15-bp DNA insert in the folP gene.
  10. Fulltext Antibiotic susceptibility profile of Haemophilus influenzae and transfer of co-trimoxazole resistance determinants
    Mohd-Zain Z, Kamsani NH, Ismail IS, Ahmad N
    Trop Biomed, 2012 Sep;29(3):372-80.
    PMID: 23018500 MyJurnal
    Prior to the implementation of Haemophilus influenzae type b vaccination worldwide, H. influenzae has been one of the main causative agents of community acquired pneumonia and meningitis in children. Due to the lack of information on the characteristics of the H. influenzae isolates that have previously been collected in Malaysia, the H. influenzae were assessed of their microbial susceptibility to commonly used antibiotics. Emphasis was made on strains that were resistance to co-trimoxazole (SXT) and their mode of transfer of the antibiotic resistance determinants were examined. A collection of 34 H. influenzae isolates was serotyped and antimicrobial susceptibility tests were performed to 11 antibiotics. To the isolates that were found to be resistant to co-trimoxazole, minimum inhibition concentration (MIC) to SXT was performed using Etest while agar dilution method was used to measure the individual MICs of trimethoprim (TMP) and sulfamethoxazole (SUL). These isolates were also examined for presence of plasmid by PCR and isolation method. Conjugal transfers of SXT-resistant genes to SXT-susceptible hosts were performed to determine their rate of transfer. Result showed that 20.6% of the total number of isolates was serotype B while the remaining was non-typeable. Antimicrobial susceptibility profile of all the isolates revealed that 58.8% was resistant to at least one antibiotic. Majority of these isolates were equally resistant to ampicillin and tetracycline (29.4% each), followed by resistance to SXT (26.5%). From nine isolates that were found to be SXT-resistant, five contained plasmid/s. Conjugal transfer experiment showed that these five isolates with plasmid transferred SXT-resistance determinants at a higher frequency than those without. From these observations, it is postulated that plasmid is not involved in the transfer of SXT-resistance genes but presence of plasmid facilitates their transfer. The information obtained from this study provides some basic knowledge on the antimicrobial susceptibility pattern of the H. influenzae isolates and their mode of transfer of SXT-resistance genes.
  11. Fulltext Occurrence of virulent genes among environmental isolates of Legionella pneumophila serogroup 1 strains from various parts of peninsular Malaysia
    Arushothy R, Ahmad N
    Trop Biomed, 2008 Dec;25(3):259-61.
    PMID: 19287368
    Legionella pneumophila are intracellular pathogens, associated with human disease, attributed to the presence and absence of certain virulent genes. In this study, virulent gene loci (lvh and rtxA regions) associated with human disease were determined. Thirty-three cooling tower water isolates, isolated between 2004 to 2006, were analyzed for the presence of these genes by PCR method. Results showed that 19 of 33 (57.5%) of the L. pneumophila serogroup 1 isolates have both the genes. Six (18.2%) of the isolates have only the lvh gene and 2 (6.1%) of the isolates have only the rtxA gene. However, both genes were absent in 6 (18.2%) of the L. pneumophila isolates. The result of our study provides some insight into the presence of the disease causing L. pneumophila serogroup 1 in the environment. Molecular epidemiological studies will provide better understanding of the prevalence of the disease in Malaysia.
  12. Fulltext Role of Restorativeness in Improving the Psychological Well-Being of University Students
    Yusli NANM, Roslan S, Zaremohzzabieh Z, Ghiami Z, Ahmad N
    Front Psychol, 2021;12:646329.
    PMID: 34489779 DOI: 10.3389/fpsyg.2021.646329
    Many university students experience high levels of study-related fatigue, hence, necessitating opportunities for restoration. They could potentially benefit from campus-based physical activities that provide them with effective restoration breaks and allow them to return to their studies cognitively refreshed. Thus, a cross-sectional study was conducted to assess the association between perceived restorativeness among postgraduates and their psychological well-being by using the four constructs of Kaplan's attention restoration theory (ART): fascination, being away, extent, and compatibility. In this study, nature view windows were also used as a moderator. Malaysian postgraduate students [n = 192; 94 females; age in years (M = 30.64, SD = 2.73)] completed the Ryff's scale of psychological wellbeing (PWB) and perceived restorativeness scale for activity (PRAS). This study used the partial least squares-structural equation model (PLS-SEM) to examine these relationships. The results demonstrate that three ART constructs, namely, being away, fascination, and compatibility, are significant predictors of psychological well-being across the sample size. Furthermore, for participants who reside in university dormitories, windows that overlook nature can enhance the relationship of being away, compatibility, and fascination to psychological well-being, compared with those with less natural views. Thus, this study confirmed the moderating effect of nature view windows and provided insight into the ART constructs that facilitate and enhance restorative experiences. By strengthening ART with additional factors, this study has also contributed toward the improvement of the psychological well-being of university students.
  13. Optimization of Water/Oil/Surfactant System for Preparation of Medium-Chain-Length Poly-3-Hydroxyalkanoates (mcl-PHA)-Incorporated Nanoparticles via Nanoemulsion Templating Technique
    Ishak KA, Annuar MSM, Ahmad N
    Appl Biochem Biotechnol, 2017 Dec;183(4):1191-1208.
    PMID: 28502064 DOI: 10.1007/s12010-017-2492-6
    Polymeric nanoparticles gain a widespread interest in food and pharmaceutical industries as delivery systems that encapsulate, protect, and release lipophilic compounds such as omega-3 fatty acids, fat-soluble vitamins, carotenoids, carvedilol, cyclosporine, and ketoprofen. In this study, medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA)-incorporated nanoparticle was developed via facile organic solvent-free nanoemulsion templating technique. The water content (W/surfactant-to-oil (S/O)), S/O, and Cremophor EL-to-Span 80 (Cremo/Sp80) ratios were first optimized using response surface methodology (RSM) to obtain nanoemulsion template prior to incorporation of mcl-PHA. Their effects on nanoemulsion formation were investigated. The mcl-PHA-incorporated nanoparticle system showed a good preservation capability of β-carotene and extended storage stability.
  14. Fulltext Exoskeleton robot control for synchronous walking assistance in repetitive manual handling works based on dual unscented Kalman filter
    Sado F, Yap HJ, Ghazilla RAR, Ahmad N
    PLoS One, 2018;13(7):e0200193.
    PMID: 30001415 DOI: 10.1371/journal.pone.0200193
    Prolong walking is a notable risk factor for work-related lower-limb disorders (WRLLD) in industries such as agriculture, construction, service profession, healthcare and retail works. It is one of the common causes of lower limb fatigue or muscular exhaustion leading to poor balance and fall. Exoskeleton technology is seen as a modern strategy to assist worker's in these professions to minimize or eliminate the risk of WRLLDs. Exoskeleton has potentials to benefit workers in prolong walking (amongst others) by augmenting their strength, increasing their endurance, and minimizing high muscular activation, resulting in overall work efficiency and productivity. Controlling exoskeleton to achieve this purpose for able-bodied personnel without impeding their natural movement is, however, challenging. In this study, we propose a control strategy that integrates a Dual Unscented Kalman Filter (DUKF) for trajectory generation/prediction of the spatio-temporal features of human walking (i.e. joint position, and velocity, and acceleration) and an impedance cum supervisory controller to enable the exoskeleton to follow this trajectory to synchronize with the human walking. Experiment is conducted with four subjects carrying a load and walking at their normal speed- a typical scenario in industries. EMG signals taken at two muscles: Right Vastus Intermedius (on the thigh) and Right Gastrocnemius (on the calf) indicated reduction in muscular activation during the experiment. The results also show the ability of the control system to predict spatio-temporal features of the pilots' walking and to enable the exoskeleton to move in concert with the pilot.
  15. Risk factors for high death and loss-to-follow-up rates among patients with multidrug-resistant tuberculosis at a programmatic management unit
    Javaid A, Shaheen Z, Shafqat M, Khan AH, Ahmad N
    Am J Infect Control, 2017 Feb 01;45(2):190-193.
    PMID: 27769706 DOI: 10.1016/j.ajic.2016.07.026
    Among 186 retrospectively evaluated patients with multidrug-resistant tuberculosis, 33.9% were cured, 6.6% completed treatment, 25% died, 18.3% were lost to follow-up, 2.2% failed treatment, and 13.8% were still undergoing treatment by the end of the study period. Rural residence was a risk factor for loss to follow-up (odds ratio [OR], 3.315; P = .016), whereas baseline body weight <40 kg (OR, 2.175; P = .042) and resistance to ofloxacin (OR, 2.889; P = .025) were risk factors for death. Despite programmatic management, treatment outcomes of the current cohort were distressing.
  16. Estimation of the Direct Cost of Poliomyelitis Rehabilitation Treatment to Pakistani Patients: A 53-Year Retrospective Study
    Naqvi AA, Naqvi SBS, Zehra F, Verma AK, Usmani S, Badar S, et al.
    Appl Health Econ Health Policy, 2018 12;16(6):871-888.
    PMID: 30128833 DOI: 10.1007/s40258-018-0422-6
    BACKGROUND: Pakistan is one of the last few countries in which poliomyelitis is endemic. Evidence indicates that out-of-pocket expenditures are a barrier to polio rehabilitation treatment, yet there are no reported figures related to the financial burden of this disease on patients in a recently polio-endemic country.

    OBJECTIVE: This study investigated direct costs attributed to rehabilitation treatment of poliomyelitis among Pakistani patients and reported its duration along with the socioeconomic status of poliomyelitis survivors.

    CONCLUSION: The cost of poliomyelitis rehabilitation in Pakistan is high; it has an economic effect on the lives of patients and their families. Despite good education, polio survivors in Pakistan appear to have low socioeconomic status, lower chances of employment and marriage, as well as fewer children. Further research is recommended to explore the burden of disease on society, i.e., indirect costs and suffering.

  17. Fabrication of alginate microspheres for drug delivery: A review
    Uyen NTT, Hamid ZAA, Tram NXT, Ahmad N
    Int J Biol Macromol, 2020 Jun 15;153:1035-1046.
    PMID: 31794824 DOI: 10.1016/j.ijbiomac.2019.10.233
    Alginate microspheres (AMs) have received much attention as a novel drug delivery system owing to various advantages of alginate such as inexpensiveness, nontoxicity, biocompatibility and biodegradability. The well-designed fabrication method is essential to achieve desired AMs suitable for specific drug delivery system. Reports on AMs preparation techniques have increased rapidly in the last decade. A number of synthesis parameters have been investigated for the improvement of physical, chemical and biological properties of AMs. Hence, this review summarizes the work to date on the fabrication techniques of AMs for drug delivery system, including spray-drying, extrusion and emulsification/gelation technique. Besides, the influence of various factors such as alginate concentration, oil phase, surfactant, cross-linker concentrations, cross-linking time, stirring speed, model drug and drug content on the morphologies, properties and encapsulation efficiency (EE) of AMs via extrusion and emulsification/gelation technique are summarized. Before embarking on the development of any drug delivery system, a thorough understanding of drug release mechanism and factors that impact the drug release profile are essential, which are also covered in this review.
  18. Fulltext Multidrug-resistant Streptococcus pneumoniae causing invasive pneumococcal disease isolated from a paediatric patient
    Arushothy R, Ramasamy H, Hashim R, Raj A S S, Amran F, Samsuddin N, et al.
    Int J Infect Dis, 2020 Jan;90:219-222.
    PMID: 31682962 DOI: 10.1016/j.ijid.2019.10.037
    The emergence of non-vaccine multidrug-resistant Streptococcus pneumoniae serotypes is on rise. This study was performed to investigate a highly resistant serotype 15A S. pneumoniae isolated from the blood specimen of a 20-month-old patient who died of her infection. The SS40_16 isolate was resistant to erythromycin, co-trimoxazole, tetracycline, and chloramphenicol, as well as to penicillin, ceftriaxone, and cefotaxime (using meningitis cut-off points, Clinical and Laboratory Standards Institute). The isolate belonged to sequence type 1591 (ST1591) and was related to CC81 clonal complex, suggesting the possibility of horizontal gene transfer. Scanning electron microscopy comparison between resistant and sensitive pneumococcal isolates also indicated similar phenotypic characteristics that confer high resistance. The emergence of highly resistant non-vaccine pneumococci is of great concern to public health and in the clinical setting. Pneumococcal surveillance programs represent a crucial tool, not only for determining the impact of pneumococcal conjugate vaccines, but also for monitoring the selective pressure of serotype replacement with regard to the treatment of invasive pneumococcal disease.
  19. Fulltext Detection of Antimicrobial Resistance Genes Associated with Carbapenem Resistance from the Whole-Genome Sequence of Acinetobacter baumannii Isolates from Malaysia
    Rao M, Rashid FA, Shukor S, Hashim R, Ahmad N
    Can J Infect Dis Med Microbiol, 2020;2020:5021064.
    PMID: 32318127 DOI: 10.1155/2020/5021064
    Background: The spread of carbapenem-resistant A. baumannii (CrAb) is gaining worldwide attention. The spread of this pathogen is largely due to its ability to acquire various resistance genes of intrinsic and extrinsic origins that confer unpredictable susceptibility to β-lactams. The aim of this study was to analyze β-lactamase genetic compositions of CrAb in Malaysia.

    Methods: Whole-genome sequencing (WGS) was carried out on 13 CrAb isolates from clinical samples in Malaysia from 2011 to 2016.

    Results: Endotracheal aspirate was the dominant clinical sample source (n = 6), and only one isolate was obtained from wound swab. A total of 6 sequence types (STs) of the Oxford scheme were identified, including 4 reported STs and 2 novel STs. Eleven isolates were classified into clonal complex 92 (CC92/ICII), among which ST195 and ST208 were the most prevalent STs. All 13 CrAb isolates harbored multiple β-lactamase genes. blaOXA-23 (n = 13) and blaOXA-66 (n = 11) were the dominant carbapenemase gene families found in these isolates. All isolates harbor blaADC, blaOXA-51-like, and blaOXA-23-like genes. blaTEM (n = 7), blaNDM-1 (n = 3), blaCARB-8 (n = 1), and blaPER-3 (n = 1) are amongst other β-lactamase genes found in this study. ISAba1 was found upstream to blaOXA-23 (n = 13), blaOXA-66 (n = 1), and blaADC (n = 11). All blaNDM-1 isolates had ISAba125 (mobile genetic element) upstream to the genes. All isolates were positive for Tn2006/2008 and Tn2009 but were negative for Tn2007.

    Conclusion: Most of the isolates were grouped under the CC92 clonal complex which belongs to international clonal lineage 2. These findings predict that carriage of carbapenem-resistant genes possibly constitutes the underlying basis of high level of international clone II prevalence. Therefore, molecular surveillance and antimicrobial stewardship are essential in implementing policies to prevent and control the spread of CrAb in hospital settings.

  20. Controlled release fertilizer: A review on developments, applications and potential in agriculture
    Vejan P, Khadiran T, Abdullah R, Ahmad N
    J Control Release, 2021 Nov 10;339:321-334.
    PMID: 34626724 DOI: 10.1016/j.jconrel.2021.10.003
    Controlled release fertilizer (CRF) plays a crucial yet necessary part in the sustainable agriculture industry. An alarming rise in call for crop production directly influences the increasing need for synthetically derived fertilizers and pesticides production. The application of CRF has been a gamechanger as an environmentally sustainable pathway to increase crop yields by paving desired phase of plant growth via a direct or indirect mechanism. The mechanism of CRF does not only decreases nutrient dissipation due to volatilization and leaching, but also provides a precisely appropriate nutrient release design that is suitable in the physiological and biochemical aspect of the plant growth. However, CRF is not deployed on larger scale of commercial agriculture practices due to being expensive, has relatively low efficiency in releasing nutrients and its coatings are largely composed of petroleum-based synthetic polymers. Alternatively, there are many polymers derived from renewable and biodegradable sources that can be used as coating material for CRF in the form of bio-nanocomposites. Having said that, there is an apparent gap between the mechanism of the CRFs for promoting plant growth and the prominent role of the nanocomposites especially bio-nanocomposites as coating material for CRF synthesis, thus the importance of nanotechnology application in enhancing the effectiveness of CRF. Therefore, this review attempts to bridge the stated gap and summarizes the comprehensive developments, application mechanisms and future potential of CRF as a fertilizer for crop sustainability.
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