Browse publications by year: 2021

  1. Jamaludin MR, Lai KW, Chuah JH, Zaki MA, Hum YC, Tee YK, et al.
    Behav Neurol, 2021;2021:2684855.
    PMID: 34777631 DOI: 10.1155/2021/2684855
    Spine surgeries impose risk to the spine's surrounding anatomical and physiological structures especially the spinal cord and the nerve roots. Intraoperative neuromonitoring (IONM) is a technology developed to monitor the integrity of the spinal cord and the nerve roots via the surgery. Transcranial motor evoked potential (TcMEP) (one of the IONM modalities) is adopted to monitor the integrity of the motor pathway of the spinal cord and the motor nerve roots. Recent research suggested that the IONM is conducive as a prognostic tool towards the patient's functional outcome. This paper summarizes the researches of IONM being adopted as a prognostic tool. In addition, this paper highlights the problems associated with the signal parameters as the improvement criteria in the previous researches. Lastly, we review the challenges of TcMEP to achieve a prognostic tool focusing on the factors that could interfere with the generation of a stable TcMEP response. The final section will discuss recommendations for IONM technology to achieve an objective prognostic tool.
    MeSH terms: Humans; Spinal Cord; Spine/surgery; Evoked Potentials, Motor*; Neurosurgical Procedures; Intraoperative Neurophysiological Monitoring*
  2. Mohd Asri MA, Nordin AN, Ramli N
    Biomicrofluidics, 2021 Dec;15(6):061502.
    PMID: 34777677 DOI: 10.1063/5.0071176
    Integrated microfluidic biosensors enable powerful microscale analyses in biology, physics, and chemistry. However, conventional methods for fabrication of biosensors are dependent on cleanroom-based approaches requiring facilities that are expensive and are limited in access. This is especially prohibitive toward researchers in low- and middle-income countries. In this topical review, we introduce a selection of state-of-the-art, low-cost prototyping approaches of microfluidics devices and miniature sensor electronics for the fabrication of sensor devices, with focus on electrochemical biosensors. Approaches explored include xurography, cleanroom-free soft lithography, paper analytical devices, screen-printing, inkjet printing, and direct ink writing. Also reviewed are selected surface modification strategies for bio-conjugates, as well as examples of applications of low-cost microfabrication in biosensors. We also highlight several factors for consideration when selecting microfabrication methods appropriate for a project. Finally, we share our outlook on the impact of these low-cost prototyping strategies on research and development. Our goal for this review is to provide a starting point for researchers seeking to explore microfluidics and biosensors with lower entry barriers and smaller starting investment, especially ones from low resource settings.
  3. Ching ME, Joan LZY, Nambiar P
    Case Rep Dent, 2021;2021:4077930.
    PMID: 34777877 DOI: 10.1155/2021/4077930
    During routine imaging of the craniofacial region, it is recognised that some "cosmetic" procedures with metallic insertions can be revealed radiographically. These objects however make it difficult to obtain a good interpretation of anatomical structures for management of diseases. A 58-year-old female patient visited a private dental facility in Kuala Lumpur for prosthodontic replacement of missing teeth. The dental panoramic image revealed generalized bone loss and numerous unusual multiple thread-like radioopacities. These gold threads made radiographic evaluation difficult and complicated the process of treatment planning for dental implant placement advocated for this patient.
  4. Liu K, Nakamura K, Katsukawa H, Nydahl P, Ely EW, Kudchadkar SR, et al.
    Front Med (Lausanne), 2021;8:735860.
    PMID: 34778298 DOI: 10.3389/fmed.2021.735860
    Background: Data regarding delivery of evidence-based care to critically ill patients in Intensive Care Units (ICU) during the COVID-19 pandemic is crucial but lacking. This study aimed to evaluate the implementation rate of the ABCDEF bundle, which is a collection of six evidence-based ICU care initiatives which are strongly recommended to be incorporated into clinical practice, and ICU diaries for patients with and without COVID-19 infections in ICUs, and to analyze the impact of COVID-19 on implementation of each element of the bundle and independent associated factors. Methods: A world-wide 1-day point prevalence study investigated the delivery of the ABCDEF bundle and ICU diary to patients without or with COVID-19 infections on 27 January 2021 via an online questionnaire. Multivariable logistic regression analysis with adjustment for patient demographics evaluated the impact of COVID-19 and identified factors in ICU administrative structures and policies independently associated with delivery. Results: From 54 countries and 135 ICUs, 1,229 patients were eligible, and 607 (49%) had COVID-19 infections. Implementation rates were: entire bundle (without COVID-19: 0% and with COVID-19: 1%), Element A (regular pain assessment: 64 and 55%), Element B (both spontaneous awakening and breathing trials: 17 and 10%), Element C (regular sedation assessment: 45 and 61%), Element D (regular delirium assessment: 39 and 35%), Element E (exercise: 22 and 25%), Element F (family engagement/empowerment: 16 and 30%), and ICU diary (17 and 21%). The presence of COVID-19 was not associated with failure to implement individual elements. Independently associated factors for each element in common between the two groups included presence of a specific written protocol, application of a target/goal, and tele-ICU management. A lower income status country and a 3:1 nurse-patient ratio were significantly associated with non-implementation of elements A, C, and D, while a lower income status country was also associated with implementation of element F. Conclusions: Regardless of COVID-19 infection status, implementation rates for the ABCDEF bundle, for each element individually and an ICU diary were extremely low for patients without and with COVID-19 infections during the pandemic. Strategies to facilitate implementation of and adherence to the complete ABCDEF bundle should be optimized and addressed based on unit-specific barriers and facilitators.
  5. Soedjono ES, Slamet A, Fitriani N, Sumarlan MS, Supriyanto A, Mitha Isnadina DR, et al.
    Heliyon, 2021 Nov;7(11):e08268.
    PMID: 34778575 DOI: 10.1016/j.heliyon.2021.e08268
    Coagulation and flocculation using bittern coagulant are effective methods for processing batik industrial wastewater containing heavy metals and high turbidity. Bittern as residual seawater product from salt production can be used as a natural coagulant as it contains magnesium (Mg2+), chloride (Cl-), and sulfate ions (SO4 2-) which can react with Pb2+ and turbidity to produce precipitation. This study focused on Pb2+ and turbidity removal from batik wastewater by introducing different variations of coagulant doses and variations in fast-stirring speed. Bittern coagulant dosage (v/v) of 5%, 15%, 25%, and 35% were used while fast-stirring speed were 55 rpm, 90 rpm, and 125 rpm. Results of this experiment showed that variations of coagulants and stirring speed to give Pb2+ maximum removal of 99.3% happened when coagulant dose and stirring speed at 35% and 55 rpm, while maximum turbidity removal at 97% happened when coagulant dose and stirring speed was 15 % and 125 rpm, respectively. Optimum dose using Response Surface Methodology (RSM) was at coagulant dose of 25% with 55 rpm, of which Pb2+ and turbidity removal were 99% and 93%, respectively.
  6. Iber BT, Kasan NA
    Heliyon, 2021 Nov;7(11):e08283.
    PMID: 34778576 DOI: 10.1016/j.heliyon.2021.e08283
    Aquaculture has been celebrated globally and believed to usher in a viable alternative to capture fisheries. It is most welcomed especially now that the world population explosion has pushed the demand on fisheries products to worrisome limits. Shrimp farming is an area of aquaculture that has witnessed significant growth in recent years, contributing substantially to the global aquaculture production. However, intensification of shrimp aquaculture has come with unintended consequences such as wastewater management and other problems emanating from environmental impact of the wastewater. This study identified excess feed and fertilizer application, metabolite wastes, shrimp mortalities, oil spillage from farm machines, drug and chemical abuse as some of the activities contributing to wastewater generation in shrimp aquaculture farming. The impact of shrimp effluent water discharged has been observed to be socio-economic with both positive and negative dimensions. In attempt to overcome the overwhelming problems associated with shrimp effluent water and bring reassurances to its sustainability, a good number of new technological approaches have been identified including caviation, high-rate algal pond system, use of nanomaterials, biofloc technology, nanoadsorbent and polymeric nanoadsorbents. Although all have been proven to be useful, none could boast of a complete and integrated approach that considers all the technological, legal, social, environmental, public health and institutional concerns.
  7. Al-Hajri S, Negash BM, Rahman MM, Haroun M, Al-Shami TM
    ACS Omega, 2021 Nov 09;6(44):29537-29546.
    PMID: 34778625 DOI: 10.1021/acsomega.1c03653
    Polymers play a major role in developing rheology of fracturing fluids for multistage hydraulic fracturing horizontal wells in unconventional reservoirs. Reducing the amount of polymer adsorbed in the shale formation is essential to maintain the polymer efficiency. In this study, the ability of silica nanoparticles to minimize polymer adsorption in Marcellus shale formation at reservoir temperature was investigated. Partially hydrolyzed polyacrylamide polymers of varying molecular weights (1-12 MD), salinities (2500-50,000 ppm), polymer concentrations (100-2000 ppm), and silica nanoparticle concentrations (0.01-0.1 w/w) were used in the static adsorption experiments. Adsorption of the polymer in the Marcellus shale samples was contrasted with and without the silica nanoparticles at a Marcellus formation reservoir temperature of 65 °C, showing a significant polymer adsorption reduction of up to 50%. The adsorption and adsorption reduction were more sensitive to the variation of the polymer concentration than to the variation of the salinity within the tested conditions. The highest adsorptions were reported at the higher molecular weight of 10-12 MD. In addition, silica nanoparticles significantly improved polymer rheology at elevated temperatures. The results indicate that nanoparticles can play a significant role in reducing polymer adsorption in the fracturing fluid and improve its rheological properties and its efficiency, which will reduce the number of issues caused by the polymers in the fracturing fluid and making it more cost effective.
  8. Zaharim WN, Ahmad SNA, Sulaiman S, Rozak H, Hasan Baseri DF, Mohamad Rosli NA, et al.
    ACS Omega, 2021 Nov 09;6(44):29641-29650.
    PMID: 34778635 DOI: 10.1021/acsomega.1c03956
    Density functional theory method at the B3LYP/6-31G level was used to determine the structure of 12mer single-strand guanine oligomers. The length and width of the optimized structure are 38.7 and 18.2 Å, respectively, and the observed high-resolution transmission electron microscopy image of the 12mer single-strand guanine sample shows similar oligomer dimensions with the calculated ones. Both HOMO and LUMO are significantly delocalized, and the calculated HOMO-LUMO gap is 3.31 eV. A total of 96 muonium trapping sites at C2, C4, C5, C6, C8, N3, N7, and O6 were investigated. All 12 C8 sites have lower energy than the other 84 sites and are clustered in the energy-muon hyperfine coupling constant scatter plot. The calculated muon hyperfine coupling constant at C8 sites range from 384.6 to 481.1 MHz, and the corresponding estimated ALC-μSR resonance for |ΔM| = 1 range from 1.419 to 1.775 T.
  9. Vijayam B, Supriyanto E, Malarvili MB
    Front Digit Health, 2021;3:723204.
    PMID: 34778867 DOI: 10.3389/fdgth.2021.723204
    The study of carbon dioxide expiration is called capnometry. The graphical representation of capnometry is called capnography. There is a growing interest in the usage of capnography as the usage has expanded toward the study of metabolism, circulation, lung perfusion and diffusion, quality of spontaneous respiration, and patency of airways outside of its typical usage in the anesthetic and emergency medicine field. The parameters of the capnograph could be classified as carbon dioxide (CO2) concentration and time points and coordinates, slopes angle, volumetric studies, and functional transformation of wave data. Up to date, there is no gold standard device for the calculation of the capnographic parameters. Capnography digitization using the image processing technique could serve as an option. From the algorithm we developed, eight identical breath waves were tested by four investigators. The values of the parameters chosen showed no significant difference between investigators. Although there were no significant differences between any of the parameters tested, there were a few related parameters that were not calculable. Further testing after refinement of the algorithm could be done. As more capnographic parameters are being derived and rediscovered by clinicians and researchers alike for both lung and non-lung-related diseases, there is a dire need for data analysis and interpretation. Although the proposed algorithm still needs minor refinements and further large-scale testing, we proposed that the digitization of the capnograph via image processing technique could serve as an intellectual option as it is fast, convenient, easy to use, and efficient.
  10. Won KY, Gass K, Biamonte M, Dagne DA, Ducker C, Hanna C, et al.
    PLoS Negl Trop Dis, 2021 11;15(11):e0009968.
    PMID: 34780503 DOI: 10.1371/journal.pntd.0009968
    As lymphatic filariasis (LF) programs move closer to established targets for validation elimination of LF as a public health problem, diagnostic tools capable of supporting the needs of the programs are critical for success. Known limitations of existing diagnostic tools make it challenging to have confidence that program endpoints have been achieved. In 2019, the World Health Organization (WHO) established a Diagnostic Technical Advisory Group (DTAG) for Neglected Tropical Diseases tasked with prioritizing diagnostic needs including defining use-cases and target product profiles (TPPs) for needed tools. Subsequently, disease-specific DTAG subgroups, including one focused on LF, were established to develop TPPs and use-case analyses to be used by product developers. Here, we describe the development of two priority TPPs for LF diagnostics needed for making decisions for stopping mass drug administration (MDA) of a triple drug regimen and surveillance. Utilizing the WHO core TPP development process as the framework, the LF subgroup convened to discuss and determine attributes required for each use case. TPPs considered the following parameters: product use, design, performance, product configuration and cost, and access and equity. Version 1.0 TPPs for two use cases were published by WHO on 12 March 2021 within the WHO Global Observatory on Health Research and Development. A common TPP characteristic that emerged in both use cases was the need to identify new biomarkers that would allow for greater precision in program delivery. As LF diagnostic tests are rarely used for individual clinical diagnosis, it became apparent that reliance on population-based surveys for decision making requires consideration of test performance in the context of such surveys. In low prevalence settings, the number of false positive test results may lead to unnecessary continuation or resumption of MDA, thus wasting valuable resources and time. Therefore, highly specific diagnostic tools are paramount when used to measure low thresholds. The TPP process brought to the forefront the importance of linking use case, program platform and diagnostic performance characteristics when defining required criteria for diagnostic tools.
    MeSH terms: Diagnostic Tests, Routine/methods; Diagnostic Tests, Routine/standards*; Elephantiasis, Filarial/diagnosis*; Elephantiasis, Filarial/drug therapy; Elephantiasis, Filarial/prevention & control; Humans; Public Health; World Health Organization
  11. Sirunyan AM, Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, et al.
    Eur Phys J C Part Fields, 2021;81(8):723.
    PMID: 34780581 DOI: 10.1140/epjc/s10052-021-09472-3
    A search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at s = 13 TeV at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 fb - 1 collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. No excess of events with respect to the standard model background predictions is observed. Model independent upper limits at 95% confidence level are reported on the product of the cross section and branching fraction for vector boson fusion production of charged Higgs bosons as a function of mass, from 200 to 3000 GeV . The results are interpreted in the context of the Georgi-Machacek model.
  12. Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, Erö J, et al.
    Eur Phys J C Part Fields, 2021;81(8):688.
    PMID: 34780582 DOI: 10.1140/epjc/s10052-021-09348-6
    A search is presented for a heavy vector resonance decaying into a Z boson and the standard model Higgs boson, where the Z boson is identified through its leptonic decays to electrons, muons, or neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137 fb - 1 . Upper limits are derived on the production of a narrow heavy resonance Z ' , and a mass below 3.5 and 3.7 Te is excluded at 95% confidence level in models where the heavy vector boson couples predominantly to fermions and to bosons, respectively. These are the most stringent limits placed on the Heavy Vector Triplet Z ' model to date. If the heavy vector boson couples exclusively to standard model bosons, upper limits on the product of the cross section and branching fraction are set between 23 and 0.3 fb for a Z ' mass between 0.8 and 4.6 Te , respectively. This is the first limit set on a heavy vector boson coupling exclusively to standard model bosons in its production and decay.
  13. Soh EYS, Lim SS, Chew KW, Phuang XW, Ho VMV, Chu KYH, et al.
    Environ Res, 2021 Nov 13.
    PMID: 34780790 DOI: 10.1016/j.envres.2021.112385
    The effluent of textile industries containing synthetic dyes contributed to substantial pollution to water bodies. The biosorption process of Congo Red dye was successfully performed by integrating ultrasonication in the adsorption step with spent brewery yeast as a novel and renewable biosorbent. The adsorption process was hindered when ultrasonication was employed together with the biosorbent, indicating that desorption process had occurred. The adsorption process showed that 4 g/L of biosorbent was the optimum dosage for adsorption of 50 mg/L of Congo Red dye, and that the adsorption equilibrium fitted to the Langmuir model, with kinetics best fitted with pseudo-second order model. The maximum capacity of the adsorption was 52.6 mg/g, showing the potential of spent brewery yeast to aid in removing wastewater pollutants. Maximal Congo Red dye recovery (100%) was achieved in the sonication-assisted desorption studies using 0.01M NaOH as the eluting agent. The ultrasonication effects contributed to the efficient recovery of dye and good conversion of spent brewery yeast to biosorbent can be beneficial for treating pollution from textile wastewater.
  14. Verma DK, Sood N, Paria A, Swaminathan TR, Mohan CV, Rajendran KV, et al.
    Virus Res, 2021 Nov 12;308:198625.
    PMID: 34780882 DOI: 10.1016/j.virusres.2021.198625
    The tilapia lake virus (TiLV), a highly infectious negative-sense single-stranded segmented RNA virus, has caused several outbreaks worldwide since its first report from Israel in 2014, and continues to pose a major threat to the global tilapia industry. Despite its economic importance, little is known about the underlying mechanisms in the genomic evolution of this highly infectious viral pathogen. Using phylogenomic approaches to the genome sequences of TiLV isolates from various geographic regions, we report on the pervasive role of reassortment, selection, and mutation in TiLV evolution. Our findings provided the evidence of genome-wide reassortment in this newly discovered RNA virus. The rate of non-synonymous (dN) to synonymous (dS) substitutions was less than one (dN/dS = 0.076 to 0.692), indicating that each genomic segment has been subjected to purifying selection. Concurrently, the rate of nucleotide substitution for each genomic segment was in the order of 1-3 × 10-3 nucleotide substitutions per site per year, which is comparable to the rate of other RNA viruses. Collectively, in line with the results of the previous studies, our results demonstrated that reassortment is the dominant force in the evolution and emergence of this highly infectious segmented RNA virus.
  15. Chu JK, Tiong TJ, Chong S, Asli UA, Yap YH
    Ultrason Sonochem, 2021 Dec;80:105818.
    PMID: 34781044 DOI: 10.1016/j.ultsonch.2021.105818
    Recently, multi-frequency systems were reported to improve performance in power ultrasound applications. In line with this, digital prototyping of multi-frequency sonoreactors also started gaining interest. However, the conventional method of simulating multi-frequency acoustic pressure fields in the time-domain led to many challenges and limitations. In this study, a multi-frequency sonoreactor was characterised using frequency domain simulations in 2-D. The studied system consists of a hexagonal sonoreactor capable of operating at 28, 40 and 70 kHz. Four frequency combinations were studied: 28-40, 28-70, 40-70 and 28-40-70 kHz. A semi-empirical, modified Commander and Prosperetti model was used to describe the bubbly-liquid effects in the sonoreactor. The root-mean-squared acoustic pressure was compared against experimental validation results using sonochemiluminescence (SCL) images and was noted to show good qualitative agreement with SCL results in terms of antinode predictions. The empirical phase speed calculated from SCL measurements was found to be important to circumvent uncertainties in bubble parameter specifications which reduces error in the simulations. Additionally, simulation results also highlighted the importance of geometry in the context of optimising the standing wave magnitudes for each working frequency due to the effects of constructive and destructive interference.
  16. Sirunyan AM, Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, et al.
    Eur Phys J C Part Fields, 2021;81(9):800.
    PMID: 34781320 DOI: 10.1140/epjc/s10052-021-09538-2
    The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton-proton collisions at s = 13 TeV in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.0% in 2015 and 2016, respectively. The dominant sources of uncertainty are related to residual differences between the measured beam positions and the ones provided by the operational settings of the LHC magnets, the factorizability of the proton bunch spatial density functions in the coordinates transverse to the beam direction, and the modeling of the effect of electromagnetic interactions among protons in the colliding bunches. When applying the van der Meer calibration to the entire run periods, the integrated luminosities when CMS was fully operational are 2.27 and 36.3 fb - 1 in 2015 and 2016, with a relative precision of 1.6 and 1.2%, respectively. These are among the most precise luminosity measurements at bunched-beam hadron colliders.
  17. Gunasagran Y, Wahab AVA
    PMID: 34517116 DOI: 10.1016/j.jpag.2021.09.001
    Congenital neonatal uterovaginal prolapse is a rare occurrence that is usually detected after delivery. Most cases are managed conservatively, although there are more invasive approaches to management. We report a case of a neonate with uterovaginal prolapse that we successfully managed conservatively. In this case, a vaginal plug made from a wet cotton ball and condom was inserted into the vaginal canal. To further reinforce the vaginal plug, a pressure garment was applied over the neonate's diaper. A trial of noninvasive methods that are simple and cost-effective should always precede other, more invasive methods in managing cases such as this.
  18. Kow RY, Che-Ahmad A, Ayeop MAS, Ahmad MW, Yusof S
    J Orthop Surg (Hong Kong), 2021 11 11;29(3):23094990211043987.
    PMID: 34753329 DOI: 10.1177/23094990211043987
    BACKGROUND: Strayer's gastrocnemius recession is a common technique in treating ankle equinus of gastrocnemius origin. Nevertheless, this technique is associated with a few flaws. We aim to introduce a novel technique of isolated gastrocnemius recession and perform a cadaveric study to evaluate its safety and at the same time compare this novel technique with the existing Strayer procedure biomechanically.

    METHODS: Eight fresh cadaveric models of gastrocnemius tightness were established by isolated traction of the gastrocnemius muscles. Gastrocnemius recession was performed on all eight models with Strayer method and the novel method randomized equally. The safety of both the techniques was evaluated by identifying any iatrogenic injury to the surrounding structures. The lengthening and improvement of the ankle dorsiflexion was measured and compared between the two techniques.

    RESULTS: There was no iatrogenic sural nerve or saphenous vein injury in all eight models. There was no significant difference between the two techniques in terms of lengthening (24.25 mm vs 21.00 mm; p = 0.838) and improvement of ankle dorsiflexion (26.5° vs 26°; p = .829).

    CONCLUSIONS: Both Strayer technique and the novel technique of gastrocnemius recession lengthened the gastrocnemius and improved the ankle dorsiflexion in this cadaver trial. Both procedures were safe with proper techniques, and there was no significant difference in efficacy between them.

    LEVEL OF EVIDENCE: Level II, randomized controlled trial.

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