Displaying publications 1 - 20 of 303 in total

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  1. Chatrchyan S, Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, et al.
    Phys Rev Lett, 2014 Apr 25;112(16):161802.
    PMID: 24815637
    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (Higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7  fb-1 of proton-proton collision data at s=8  TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the top squark mass below 360 to 410 GeV, depending on the Higgsino mass.
  2. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Eur Phys J C Part Fields, 2017;77(1):15.
    PMID: 28260978 DOI: 10.1140/epjc/s10052-016-4504-z
    A measurement of the top quark pair production ([Formula: see text]) cross section in proton-proton collisions at the centre-of-mass energy of 8[Formula: see text] is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6[Formula: see text]. This analysis is performed in the [Formula: see text] decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured [Formula: see text] cross section is [Formula: see text]. This measurement is compared with an analysis of 7[Formula: see text] data, corresponding to an integrated luminosity of 5.0[Formula: see text], to determine the ratio of 8[Formula: see text] to 7[Formula: see text] cross sections, which is found to be [Formula: see text]. The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.
  3. Lee YW, Zairi J, Yap HH, Adanan CR
    J Am Mosq Control Assoc, 2005 Mar;21(1):84-9.
    PMID: 15825767
    Studies were carried out on the bioefficacy and residual activity of Bacillus thuringiensis israelensis H-14 (Bti) (water-dispersible granules of VectoBac ABG 6511 and liquid formulations of VectoBac 12AS) and pyriproxyfen (insect growth regulator, Sumilarv 0.5%) as direct applications for control of larvae of Aedes aegypti and Aedes albopictus. Two dosages of each Bti formulation (285 and 570 international toxic units [ITU]/liter) and the integration of both Bti formulations and pyriproxyfen were used for residual tests with 45-liter earthen jars for a period of 4 wk. In 1 test series, the treated water was replenished daily with 6 liters of seasoned untreated water. In the 2nd test series, the water in the jars was topped up to the 40-liter level during evaluation. Neither Bti formulation remained effective for a full week. Water-dispersible Bti granules provided effective initial control activity against Ae. aegypti and Ae. albopictus for both test designs (with replenishment and without replenishment of water). The higher dosage (570 ITU/liter) for both Bti formulations was only partially effective at the end of 1 wk after being diluted. After 1 wk, water-dispersible Bti granules provided greater larval mortality than did liquid Bti formulation against both mosquito species when integrated with pyriproxyfen. Pyriproxyfen (79.5 and 159 mg/liter) on its own showed low larvicidal activity but provided very effective control of adult emergence. In this study, integration of Bti (285 and 570 ITU/liter) with pyriproxyfen (79.5 mg/liter) extended the duration of partial larval control somewhat, but live larvae persisted throughout the 4-wk test. The integration effect was more obvious when water-dispersible Bti granules were integrated with pyriproxyfen than when liquid Bti was used. Integration of Bti with pyriproxyfen had a negative effect on adult emergence, which was completely inhibited by pyriproxyfen after day 1. Daily replenishment of water increased Bti activity and provided slightly better larval control. Aedes albopictus and Ae. aegypti were both completely susceptible to the higher concentration of Bti and pyriproxyfen in both test designs (with replenishment and without replenishment of water).
  4. Yap HH, Lee YW, Zairi J, Jahangir K, Adanan CR
    J Am Mosq Control Assoc, 2001 Mar;17(1):28-32.
    PMID: 11345415
    Indoor bioefficacy of the thermal fogging application of Pesguard FG 161, a formulation containing both knockdown and killing agents (active ingredient [AI]: d-tetramethrin 4% [w/w] and cyphenothrin 12% [w/w]) was compared with Resigen5 (AI: s-bioallethrin 0.8% [w/w], permethrin 125/75] 18.7% [w/w], and piperonyl butoxide 16.8% [w/w]), another pyrethroid formulation, as larvicides and adulticides against Aedes aegypti, Aedes albopictus, Anopheles sinensis, and Culex quinquefasciatus using a portable Agrofog AF35 sprayer indoors in houses on Penang Island, Malaysia. Pesguard FG 161 at the concentrations tested was effective against all 4 mosquito species tested. The water-based Pesguard FG 161 performed far better as a larvicide than the diesel-based formulation. Resigen was also effective as a larvicide and adulticide against all 4 mosquito species tested. Larvae of Ae. aegypti were most susceptible to water-based Pesguard FG 161, followed by Cx. quinquefasciatus, An. sinensis, and Ae. albopictus. Even at the lowest concentrations tested, Pesguard FG 161 showed adequate adulticidal properties. At higher dosages, water-based Pesguard FG 161 proved effective as a larvicide against all 4 mosquito species.
  5. Lee YK, Za'aba A, Madzhi NK, Ahmad A
    PMID: 19964239 DOI: 10.1109/IEMBS.2009.5333674
    Previous works on the effects of salivary alpha amylase in respond to various stressors report encouraging findings on it being a good indicator of stress. Ellestad protocol is a clinical procedure to screen for coronary artery disease by introducing exercise induced physical stress. If a salivary based biomarker profile in accordance to a stress test protocol could be established, the critical stress state which disable rational decision making could be ascertained in a standardized procedure. This technique would serve to aid human resource management in times of critical events such as rescue, firefighting or even military, that would potentially prevent unnecessary sacrifice of human lives. In this pilot study with five healthy volunteers performing the Ellestad protocol treadmill, a measurement profile with physiologic and salivary based biomarker is obtained. It is found that the alpha amylase levels or the changes in it as workload changes from resting-walking-running at ease-exhaustive running, is relatively more significant in reflecting the stress state than heart rate and blood pressure. Moreover, it is strongly associated with mood state with correlation coefficient of 0.8 and significance of 0.01.
  6. Lee YJ, Harmony T, Jamal-Azmi IS, Gunasagaran J, Ahmad TS
    Malays Orthop J, 2021 Mar;15(1):113-118.
    PMID: 33880157 DOI: 10.5704/MOJ.2103.017
    Introduction: Bowling is an immensely popular, but scarcely researched sport associated with overuse injuries in its participants. The purpose of this study was to investigate and report on the incidence of common upper extremity complaints in elite bowling athletes.

    Materials and methods: All Malaysian national level bowlers (n=39) were evaluated via questionnaire on their upper limb symptoms. A focused, relevant clinical examination was performed on each subject to exclude de Quervain's tenosynovitis, tennis and golfer's elbow, carpal tunnel syndrome and trigger finger. The athletes were then allowed to resume bowling for two hours before completing another symptom-related questionnaire.

    Results: Pain was the predominantly observed symptom, with a predilection for the wrist, ring and middle fingers, and thumb. De Quervain's tenosynovitis was found in 53.8% (n=21) of the subjects, with 52.4% and 42.9% of them experiencing pain during and after training, respectively. Other repetitive injury-related disorders were also considerably more common than in their non-playing limb and the general population.

    Conclusion: The incidence of de Quervain's tenosynovitis was exceptionally high in this population. Further studies on sports kinematics are needed to prevent long term morbidities in these athletes.

  7. Reungwetwattana T, Cho BC, Lee KH, Pang YK, Fong CH, Kang JH, et al.
    J Thorac Oncol, 2023 Oct;18(10):1351-1361.
    PMID: 37702629 DOI: 10.1016/j.jtho.2023.06.016
    INTRODUCTION: Lazertinib is a third-generation central nervous system-penetrant tyrosine kinase inhibitor targeting mutant EGFR in NSCLC. Lazertinib exhibited improved efficacy versus gefitinib in the LASER301 study; this subset analysis compared lazertinib with gefitinib among Asian patients.

    METHODS: The phase 3 LASER301 study evaluated lazertinib efficacy and safety in treatment-naive patients with EGFR-mutated (exon 19 deletion or L858R) locally advanced or metastatic NSCLC. Patients were randomized one-to-one and received either lazertinib or gefitinib. The primary end point was investigator-assessed progression-free survival using Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end points included overall survival, objective response rate, duration of response, and safety.

    RESULTS: Between February 13, 2020, and July 29, 2022, among 258 patients of Asian descent, the median progression-free survival was significantly longer with lazertinib than gefitinib (20.6 versus 9.7 mo; hazard ratio: 0.46; 95% confidence interval [CI]: 0.34-0.63, p < 0.001), and the benefit was consistent across predefined subgroups (exon 19 deletion, L858R, baseline central nervous system metastases). Objective response rate and disease control rates were similar between treatment groups. The median duration of response was 19.4 months (95% CI: 16.6-24.9) versus 9.6 months (95% CI: 6.9-12.4) in the lazertinib versus gefitinib group. Adverse event rates in Asian patients were comparable with the overall LASER301 population. Adverse events leading to discontinuation in the lazertinib and gefitinib groups were 13% and 12%, respectively.

    CONCLUSIONS: In LASER301, efficacy and safety results in Asian patients were consistent with the overall population. Lazertinib exhibited better efficacy than gefitinib in Asian patients with a tolerable safety profile.

  8. Lee YM, Lim YC, Liam CK, Aljafri M
    Med J Malaysia, 1995 Dec;50(4):334-8.
    PMID: 8668053
    Five cases of spontaneous pneumothorax were treated with video-assisted thoracoscopic surgery (VATS). These included four cases of recurrent pneumothorax and one case of persistent pneumothorax. The mean age was 33 years. The identified bullae were eliminated with either endoloop ligation (in one patient) or stapled excision (in four patients). There were no recurrences reported in a mean follow-up of 9.4 months. In conclusion, VATS offers an equally effective and less morbid alternative to open thoracotomy in the management of primary spontaneous pneumothorax.
  9. Chen LK, Liu LK, Woo J, Assantachai P, Auyeung TW, Bahyah KS, et al.
    J Am Med Dir Assoc, 2014 Feb;15(2):95-101.
    PMID: 24461239 DOI: 10.1016/j.jamda.2013.11.025
    Sarcopenia, a newly recognized geriatric syndrome, is characterized by age-related decline of skeletal muscle plus low muscle strength and/or physical performance. Previous studies have confirmed the association of sarcopenia and adverse health outcomes, such as falls, disability, hospital admission, long term care placement, poorer quality of life, and mortality, which denotes the importance of sarcopenia in the health care for older people. Despite the clinical significance of sarcopenia, the operational definition of sarcopenia and standardized intervention programs are still lacking. It is generally agreed by the different working groups for sarcopenia in the world that sarcopenia should be defined through a combined approach of muscle mass and muscle quality, however, selecting appropriate diagnostic cutoff values for all the measurements in Asian populations is challenging. Asia is a rapidly aging region with a huge population, so the impact of sarcopenia to this region is estimated to be huge as well. Asian Working Group for Sarcopenia (AWGS) aimed to promote sarcopenia research in Asia, and we collected the best available evidences of sarcopenia researches from Asian countries to establish the consensus for sarcopenia diagnosis. AWGS has agreed with the previous reports that sarcopenia should be described as low muscle mass plus low muscle strength and/or low physical performance, and we also recommend outcome indicators for further researches, as well as the conditions that sarcopenia should be assessed. In addition to sarcopenia screening for community-dwelling older people, AWGS recommends sarcopenia assessment in certain clinical conditions and healthcare settings to facilitate implementing sarcopenia in clinical practice. Moreover, we also recommend cutoff values for muscle mass measurements (7.0 kg/m(2) for men and 5.4 kg/m(2) for women by using dual X-ray absorptiometry, and 7.0 kg/m(2) for men and 5.7 kg/m(2) for women by using bioimpedance analysis), handgrip strength (<26 kg for men and <18 kg for women), and usual gait speed (<0.8 m/s). However, a number of challenges remained to be solved in the future. Asia is made up of a great number of ethnicities. The majority of currently available studies have been published from eastern Asia, therefore, more studies of sarcopenia in south, southeastern, and western Asia should be promoted. On the other hand, most Asian studies have been conducted in a cross-sectional design and few longitudinal studies have not necessarily collected the commonly used outcome indicators as other reports from Western countries. Nevertheless, the AWGS consensus report is believed to promote more Asian sarcopenia research, and most important of all, to focus on sarcopenia intervention studies and the implementation of sarcopenia in clinical practice to improve health care outcomes of older people in the communities and the healthcare settings in Asia.
  10. Lee YL, Verma RK, Yadav H, Barua A
    Eur J Dent Educ, 2016 Nov;20(4):218-228.
    PMID: 26277860 DOI: 10.1111/eje.12164
    BACKGROUND: Facebook and mobile texting are prevalent in the lives of almost every student. However, little is known about the relationship between Facebook usage or mobile texting and their impacts on health amongst undergraduate dental students. In this study, excessive Facebook use and excessive mobile texting were studied as they relate to impacts on health.

    MATERIALS AND METHODS: A cross-sectional study was conducted at a private university in Malaysia. A total of 188 undergraduate dental students were interviewed using a pre-tested and self-rated questionnaire. Data collected from participants were analysed using SPSS version 18.0. Chi-square test, Fisher's exact test and multiple logistic regression analyses were applied to study the relationship between explanatory variables and excessive Facebook use and excessive mobile texting.

    RESULTS: The prevalence of excessive Facebook use and excessive mobile texting amongst undergraduate dental students was found to be 33.2% and 33.0%, respectively. According to a multivariate analysis, texting habits, such as the presence of daytime sleepiness after texting late at night (aOR = 2.682, 95% CI = 1.142-6.301) and the presence of anxious feelings if students failed to receive a timely response (aOR = 3.819, 95% CI = 1.580-9.230), were determined to be significant predictors of excessive mobile texting. Excessive Facebook use was found to be significantly related to three variables as follows: fewer numbers of close friends (aOR = 2.275, 95% CI = 1.057-4.898), the checking of updates on the Facebook walls of their friends (aOR = 2.582, 95% CI = 1.189-5.605) and the absence of active and vigorous feelings during Facebook use (aOR = 3.401, 95% CI = 1.233-9.434).

    CONCLUSIONS: Approximately one-third of undergraduate dental students in this study experienced excessive Facebook use and/or excessive mobile texting. Health education and promotion should be instituted to create awareness, whilst students should be advised to practise self-control with respect to both mobile texting and Facebook usage.

  11. Lee YK, Bister M, Salleh YM, Blanchfield P
    PMID: 19163841 DOI: 10.1109/IEMBS.2008.4650338
    Software technology enables computerized analysis to offer second opinion in various screening and diagnostic tasks to assist the clinicians. Yet, the performance of these computerized methods for medical images is questioned by experts in CAD research, owing to the use of different databases and criteria for evaluating the computer results for comparison. This paper intends to substantiate this statement by illustrating the effects of such issues with the use of 1D physiologic data and multiple databases. For this purpose, the detection of desaturation events in Sp02 and spike events in EEG are used. This is the first time that comparison between different algorithms on a common basis is carried out on an individual effort. The appraisal for all the algorithms is made on the same databases and criteria. It is surprising to find that issues for 2/3D images concur with those found in 1D data here. In evaluating the accuracy of a new algorithm, a single independent database gives results fast. This paper reveals weaknesses of such an approach. It is hoped that the supportive evidence shown here is enough for researchers to innovate a better platform for credibility in reporting performance comparison of computerized analysis algorithms.
  12. Lee YK, Bister M, Salleh YM, Blanchfield P
    PMID: 18003041
    Effect of amplitude criteria on the operating characteristics of algorithms for detecting OSAH events based on the analysis of oxygen saturation alone is investigated. The objective is to establish that there exists an oxygen desaturation level that leverages these algorithms to be more sensitive or more specific, irrespective of the differences in detection mechanism and database, a first ever attempt. Linear classification of algorithms from previous studies discovered that a drop in oxygen saturation of 3% or less makes the detection algorithms more sensitive while a drop of 4% or more makes it more specific. Results from two algorithms developed here also supported this. This finding explains the contradiction cited in the performance of algorithms from the different authors, which casts doubts on their detection ability. It could lead to the establishment of standard oxygen desaturation levels for screening and diagnosis of moderate/severe OSA, thus providing a more credible comparison basis for automated detection algorithms or even clinical tests.
  13. Kowdley KV, Sundaram V, Jeon CY, Qureshi K, Latt NL, Sahota A, et al.
    Hepatology, 2017 04;65(4):1094-1103.
    PMID: 28027579 DOI: 10.1002/hep.29005
    Eight weeks duration of ledipasvir/sofosbuvir (LDV/SOF) can be considered in genotype 1 hepatitis C virus-infected patients who are treatment-naive, do not have cirrhosis, and have a pretreatment viral load <6,000,000 IU/mL. The effectiveness of this regimen, however, has not been fully confirmed by real-world experience. Using data from real-world cohorts, we aimed to determine the effectiveness of 8 weeks of LDV/SOF treatment, examine variables associated with relapse after treatment with this regimen, and compare the effectiveness of 8 weeks and 12 weeks of LDV/SOF treatment. To evaluate the effectiveness of 8 weeks of therapy and characteristics associated with relapse, we used individual patient data from the IFI (Institut für Interdisziplinäre Medizin), Burman's Pharmacy, and Kaiser Permanente Southern California. All patients had fibrosis staging assessed with biopsy, transient elastography, or serum biomarkers. We also performed a systematic review and meta-analysis of six additional real-world cohorts, to compare effectiveness of 8 weeks to 12 weeks duration. In our pooled data analysis, 634 patients were treated for 8 weeks with LDV/SOF, of whom all had outcomes of cure or relapse without loss to follow-up. Per protocol rates of sustained virologic response at 12 weeks were 98.1% (622/634) in the full cohort and 97.9% (571/583) among treatment-eligible patients. Exact logistic regression revealed no specific patient characteristics associated with relapse. Our meta-analysis of six additional real-world cohorts, comprised of 5,637 patients, demonstrated similar risk for relapse between 8 weeks and 12 weeks of LDV/SOF (relative risk = 0.99, 95% confidence interval 0.98-1.00).

    CONCLUSION: An 8-week duration of treatment with LDV/SOF is highly effective in properly selected patients; greater use of this regimen is recommended. (Hepatology 2017;65:1094-1103).

  14. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2015 Feb 13;114(6):061801.
    PMID: 25723204
    A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at √[s]=8  TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7  fb(-1). Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-μ final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-μ final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to cτ=2  cm, excluding masses below 790 GeV at 95% confidence level.
  15. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2015 Feb 6;114(5):051801.
    PMID: 25699433
    A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4  fb(-1) collected with the CMS detector. Candidate events are selected with exactly two leptons of the same charge, two jets with large rapidity separation and high dijet mass, and moderate missing transverse energy. The signal region is expected to be dominated by electroweak same-sign W-boson pair production. The observation agrees with the standard model prediction. The observed significance is 2.0 standard deviations, where a significance of 3.1 standard deviations is expected based on the standard model. Cross section measurements for W(±)W(±) and WZ processes in the fiducial region are reported. Bounds on the structure of quartic vector-boson interactions are given in the framework of dimension-eight effective field theory operators, as well as limits on the production of doubly charged Higgs bosons.
  16. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2016 Feb 19;116(7):071801.
    PMID: 26943527 DOI: 10.1103/PhysRevLett.116.071801
    A search for narrow resonances in proton-proton collisions at sqrt[s]=13  TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4  fb^{-1}. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W^{'} bosons below 2.6 TeV. These results significantly extend previously published limits.
  17. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2016 Jan 22;116(3):032301.
    PMID: 26849587 DOI: 10.1103/PhysRevLett.116.032301
    The production cross sections of the B^{+}, B^{0}, and B_{s}^{0} mesons, and of their charge conjugates, are measured via exclusive hadronic decays in p+Pb collisions at the center-of-mass energy sqrt[s_{NN}]=5.02  TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6  nb^{-1}. The production cross sections are measured in the transverse momentum range between 10 and 60  GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in Pb+Pb collisions.
  18. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2015 Mar 13;114(10):101801.
    PMID: 25815923
    Results are presented from a search for new decaying massive particles whose presence is inferred from an imbalance in transverse momentum and which are produced in association with a single top quark that decays into a bottom quark and two light quarks. The measurement is performed using 19.7  fb^{-1} of data from proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No deviations from the standard model predictions are observed and lower limits are set on the masses of new invisible bosons. In particular, scalar and vector particles, with masses below 330 and 650 GeV, respectively, are excluded at 95% confidence level, thereby substantially extending a previous limit published by the CDF Collaboration.
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