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Fulltext A survey of therapeutic drug monitoring services in Malaysia

Ab Rahman AF, Ahmed Abdelrahim HE, Mohamed Ibrahim MI

Saudi Pharm J, 2013 Jan;21(1):19-24.
PMID: 23960816 DOI: 10.1016/j.jsps.2012.01.002

In Malaysia, therapeutic drug monitoring (TDM) service was started in the 1980s. Since then, the number of hospitals that offer the service has increased. In this paper, we report the findings of a nationwide survey describing the practice of TDM in these hospitals. Questionnaires were mailed to 128 government hospitals. Data were collected for general characteristics of the hospitals, administrative, and laboratory activities related to TDM service. One hundred and twenty-one hospitals responded to the survey. Thirty-four hospitals (28.1%) provided the service with their own TDM laboratories, 44 hospitals (36.4%) provided the service using other hospitals' laboratories and 43 hospitals (35.5%) did not provide the service at all. TDM services were more likely to be offered in larger hospitals with various medical specialties. Since it is managed entirely by hospital pharmacists, these pharmacists assume an important role in ensuring optimum use of the TDM service.

Matched MeSH terms: Laboratories, Hospital
Fulltext Clinically lesser known entity in India: A Report of two cases of Melioidosis

Barman P, Kaur R, Kumar K

Indian J Crit Care Med, 2013 Jan;17(1):46-8.
PMID: 23833477 DOI: 10.4103/0972-5229.112146

Melioidosis is endemic in the South Asian regions, like Thailand, Singapore Malaysia and Australia. The disease is more pronounced in the southern part of the country. It is caused by Burkholderia pseudomallei which causes systemic involvement, morbidity and mortality associated with the disease is high. Due to highly varied clinical presentation, and low general awareness this infection is largely underdiagnosed and under reported in our country. Most laboratories in the country still rely on conventional culturing methods with their low sensitivity, adding to the under reporting. To enhance physician awareness we describe here two cases who presented to our institute after months of misdiagnosis.

Matched MeSH terms: Laboratories
A shelf-stable fluorogenic isothermal amplification assay for the detection of Burkholderia pseudomallei

Michelle Wong Tzeling J, Yean Yean C

Analyst, 2016 Feb 21;141(4):1246-9.
PMID: 26783560 DOI: 10.1039/c5an01741f

A shelf-stable loop-mediated isothermal amplification (LAMP) reagent for Burkholderia pseudomallei detection is described. The coupling of LAMP reagents with the indirect colorimetric indicator and consequently its lyophilization enable the simple evaluation of results without the need for any advance laboratory instruments. The reagents were found to have a stable shelf life of at least 30 days with well-maintained sensitivity and specificity.

Matched MeSH terms: Laboratories
Fulltext Chest Radiograph Findings In Novel Swine-Origin Influenza A (H1N1) Virus (S-OIV) Infection: A UKMMC Experience

Norzailin AB, Norhafizah E

Med J Malaysia, 2015 Apr;70(2):93-7.
PMID: 26162384 MyJurnal

OBJECTIVE: 1.To evaluates and recognizes findings in chest radiograph in patients with laboratory-confirmed S-OIV (H1N1) infection treated at UKMMC. 2. To evaluate whether the findings on initial chest radiographs of influenza A (H1N1) patients can help to predict the prognosis.

MATERIAL AND METHODS: Total of 109 adult patients presenting to the Universiti Kebangsaan Malaysia Medical Centre (UKMMC) with flu-like symptoms who were positive for influenza A and these patients had underwent chest radiographs (CXR). The initial CXRs were evaluated for the pattern (consolidation, ground-glass, and reticulation), distribution, and extend of abnormality. The disease is classifies by the clinical severity (mild, moderate or severe illness) and adverse outcome (ventilated, death or recovered well).

RESULTS: The initial CXRs were normal in 56% of cases. The predominant radiographic finding was consolidation, most commonly involving the middle and lower zones (35% of cases). There is no significant association between initial CXR findings with the patient clinical outcome either fully recovered or death/ ventilated.

CONCLUSION: Normal chest radiographs is the most common radiographic finding in S-OIV (H1N1) infection and the most common abnormal lung finding is consolidation. Initial chest radiographs did not determine the patient clinical outcome and a normal initial radiograph could not exclude adverse outcome.

Matched MeSH terms: Laboratories
Fulltext Fine Particle Emissions From Tropical Peat Fires Decrease Rapidly With Time Since Ignition

Roulston C, Paton-Walsh C, Smith TEL, Guérette ÉA, Evers S, Yule CM, et al.

J Geophys Res Atmos, 2018 May 27;123(10):5607-5617.
PMID: 30167349 DOI: 10.1029/2017JD027827

Southeast Asia experiences frequent fires in fuel-rich tropical peatlands, leading to extreme episodes of regional haze with high concentrations of fine particulate matter (PM2.5) impacting human health. In a study published recently, the first field measurements of PM2.5 emission factors for tropical peat fires showed larger emissions than from other fuel types. Here we report even higher PM2.5 emission factors, measured at newly ignited peat fires in Malaysia, suggesting that current estimates of fine particulate emissions from peat fires may be underestimated by a factor of 3 or more. In addition, we use both field and laboratory measurements of burning peat to provide the first mechanistic explanation for the high variability in PM2.5 emission factors, demonstrating that buildup of a surface ash layer causes the emissions of PM2.5 to decrease as the peat fire progresses. This finding implies that peat fires are more hazardous (in terms of aerosol emissions) when first ignited than when still burning many days later. Varying emission factors for PM2.5 also have implications for our ability to correctly model the climate and air quality impacts downwind of the peat fires. For modelers able to implement a time-varying emission factor, we recommend an emission factor for PM2.5 from newly ignited tropical peat fires of 58 g of PM2.5 per kilogram of dry fuel consumed (g/kg), reducing exponentially at a rate of 9%/day. If the age of the fire is unknown or only a single value may be used, we recommend an average value of 24 g/kg.

Matched MeSH terms: Laboratories
Impact of the COVID-19 pandemic on cytology practice: An international survey in the Asia-Pacific region

Wang YH, Bychkov A, Chakrabarti I, Jain D, Liu Z, He S, et al.

Cancer Cytopathol, 2020 Dec;128(12):895-904.
PMID: 32931161 DOI: 10.1002/cncy.22354

BACKGROUND: The purpose of the current study was to examine the impact of coronavirus disease 2019 (COVID-19) on various aspects of cytology practice in the Asia-Pacific region.
METHODS: An online questionnaire was distributed to cytopathology laboratories in 24 Asia-Pacific countries to explore the impact of restrictive measures on access to health care, use of general and personal protective equipment (PPE), and changes in cytology workflow and workload from February to April 2020.
RESULTS: A total of 167 cytopathology laboratories from 24 countries responded to the survey; the majority reported that restrictive measures that limited the accessibility of health care services had been implemented in their cities and/or countries (80.8%) and their hospitals (83.8%). The respondents noted that COVID-19 had an impact on the cytologic workflow as well as the workload. Approximately one-half of the participants reported the implementation of new biosafety protocols (54.5%) as well as improvements in laboratory facilities (47.3%). Rearrangement or redeployment of the workforce was reported in 53.3% and 34.1% of laboratories, respectively. The majority of the respondents reported a significant reduction (>10%) in caseload associated with both gynecological (82.0%) and nongynecological specimens (78.4%). Most laboratories reported no significant change in the malignancy rates of both gynecological (67.7%) and nongynecological specimens (58.7%) compared with the same period in 2019.
CONCLUSIONS: The results of the survey demonstrated that the COVID-19 pandemic resulted in a significant reduction in the number of cytology specimens examined along with the need to implement new biosafety protocols. These findings underscore the need for the worldwide standardization of biosafety protocols and cytology practice.

Matched MeSH terms: Laboratories, Hospital/organization & administration*; Laboratories, Hospital/standards; Laboratories, Hospital/statistics & numerical data
Fulltext Evaluation of the Effects of Cement and Lime with Rice Husk Ash as an Additive on Strength Behavior of Coastal Soil

Eliaslankaran Z, Daud NNN, Yusoff ZM, Rostami V

Materials (Basel), 2021 Feb 28;14(5).
PMID: 33670914 DOI: 10.3390/ma14051140

Coastal accretion and erosion are unavoidable processes as some coastal sediments undergo modification and stabilization. This study was conducted to investigate the geotechnical behavior of soil collected from Bagan Lalang coast and treated with lime, cement, and rice husk ash (RHA) to design a low-cost alternative mixture with environmentally friendly characteristics. Laboratory tests were carried out to analyze the physical properties of the soil (Atterberg limits and compaction properties), together with mechanical characteristics (direct shear and unconfined compressive strength (UCS) tests) to determine the effect of different ratios of stabilizer/pozzolan on the coastal soil and the optimum conditions for each mixture. Part of the purpose of this study was also to analyze the shear behavior of the coastal soil and monitor the maximum axial compressive stress that the treated specimens can bear under zero confining pressure. Compared to the natural soil, the soil treated with lime and rice husk ash (LRHA) in the ratio of 1:2 (8% lime content) showed a tremendous increase in shear stress under the normal stress of 200 kPa. The strength parameters such as the cohesion (c) and internal friction angle (ϕ) values showed a significant increase. Cohesion values increased considerably in samples cured for 90 days compared to specimens cured for 7 days with additional LRHA in the ratio of 1:2 (28%).

Matched MeSH terms: Laboratories
Age-Stage, Two-Sex Life Table Characteristics of Aedes albopictus and Aedes Aegypti in Penang Island, Malaysia

Maimusa HA, Ahmad AH, Kassim NF, Rahim J

J Am Mosq Control Assoc, 2016 Mar;32(1):1-11.
PMID: 27105211 DOI: 10.2987/moco-32-01-1-11.1

The life table developmental attributes of laboratory colonies of wild strains of Aedes albopictus and Aedes aegypti were analyzed and compared based on the age-stage, two-sex life table. Findings inclusive in this study are: adult preoviposition periods, total preoviposition period, mean intrinsic rate of increase (r), mean finite rate of increase (λ), net reproductive rates (R0), and mean generation time (T). The total preadult development time was 9.47 days for Ae. albopictus and 8.76 days for Ae. aegypti. The life expectancy was 19.01 days for Ae. albopictus and 19.94 days for Ae. aegypti. Mortality occurred mostly during the adult stage. The mean development time for each stage insignificantly correlated with temperature for Ae. albopictus (r = -0.208, P > 0.05) and (r = -0.312, P > 0.05) for Ae. aegypti. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategists characterized by a high r, a large R0, and short T. This present study provides the first report to compare the life parameters of Ae. albopictus and Ae. aegypti strains from Penang island, Malaysia.

Matched MeSH terms: Laboratories
Fulltext Quisy-SDS accelerates the searching process of chemical safety datasheet

Muhammad Firdaus Othman,, Nor Aimi Abdul Wahab, Suhaiza Hasan, Marina Mokhtar, Noorezal Atfyinna Mohd Napiah, Mohd Noor Mokhtar, et al.

Jurnal Inovasi Malaysia, 2019;2(2):123-139.
MyJurnal

Teaching, learning and reseach activities in chemical laboratory usually involves a variety of hazardous chemicals. All chemicals stored in the laboratories should be accompanied by a safety data sheet which contains information such as chemical composition, safety precautions for handling and storing chemicals and emergency measures in case of accident. Ineffective management of chemical safety data sheet makes it difficult to access and resulting in slow action taken in the event of accident. To overcome this problem, Quisy-SDS was introduced to ensure a more effective chemical safety information management. Quisy-SDS provides a convenient method for all lab users and emergency respondents to acess the chemical safety information. This method uses a Quick Response (QR) code and website that allow users to acess the information in no time, anytime and anywhere. The use of Quisy-SDS has successfully reduced the search time of chemical safety information by 98% compared to the previous method.

Matched MeSH terms: Laboratories
Fulltext Bacterial identification process using BactFinder© mobile application

Nadiawati Alias, Nor Hasima Mahmod, Noor Afiza Badaluddin, Mohammad Khairul Asyraf Ridzuan

Jurnal Inovasi Malaysia, 2019;2(2):1-18.
MyJurnal

BactFinder© is an interactive and mobile application built to facilitate bacteria identification. As widely known, bacteria are composed of large domains of prokaryotic microorganisms which are various in types, hence the identification of these bacterial groups requires a systematic and orderly identification process. Through this mobile app, experimental results from biochemical and bacterial morphological tests carried out in the laboratory before hand must be submitted to the application before bacterial identification can be performed. Previously, academics user and students have to refer to many references such as research books and related academic journals in order to finalise their bacteria identification. This process, of course, will take relatively longer time and less effective. This BactFinder© mobile application is equipped with a database of 19 types of biochemical tests including bacteria morphology. The database was built based on Bergey’s Manual of Systematic Bacteriology, Bergey’s Manual of Determinative Bacteriology and other related scientific journals. The BactFinder© mobile app has been proved able to provide fast (± 2 seconds) and precise responses in helping students and academics user in the process of identifying bacteria species in the lab. This application is also suitable for undergraduate, post-graduate and academicians in the field of microbiology, biotechnology and science in general.

Matched MeSH terms: Laboratories
Genetics of glucose phosphate isomerase and phosphoglucomutase in Aedes albopictus (diptera: culicidae)

Yong HS, Chan KL, Dhaliwal SS, Cheong WH, Chiang GL, Mak JW

Theor Appl Genet, 1981 Nov;59(6):345-8.
PMID: 24276567 DOI: 10.1007/BF00276447

Glucose phosphate isomerase (E.C. 5.3.1.9) and phosphoglucomutase (E.C. 2.7.5.1) were found to be polymorphic in a laboratory colony of Aedes albopictus. The glucose phosphate isomerase locus is represented by two alleles resulting in three genotypes, while the phosphoglucomutase locus is represented by at least five alleles giving rise to a total of 15 genotypes. The inheritance of these two enzymes is of the Mendelian type with codominant alleles. Present data indicate that these genes are not linked.Of 105 mosquitoes analysed for these two gene-enzyme systems, the frequencies for glucose phosphate isomerase alleles are Gpi (S)=0.68 and Gpi (F)=0.32, while the frequencies for phosphoglucomutase alleles are Pgm (A)=0.16, Pgm (B)=0.11, Pgm (C)=0.19, Pgm (D)=0.30 and Pgm (F)= 0.24. The frequencies of the three glucose phosphate isomerase genotypes are in accord with Hardy-Weinberg expectations (X 1 (2) =2.74). Similarly, the frequencies of the 15 phosphoglucomutase genotypes probably do not differ significantly from Hardy-Weinberg expectations (X 10 (2) = 18.45).

Matched MeSH terms: Laboratories
Fulltext Review of knowledge, attitude, and practice among laboratory workers towards occupational safety and health

Nayef Shabbab Almutairi, Shamsul Bahri Bin Md Tamrin, Ng Yee Guan, Vivien How

Malaysian Journal of Medicine and Health Sciences, 2020;16(1):297-303.
MyJurnal

Laboratory workers exposed to diverse occupational exposures to accidents. Evidently, extant, yet very limited em- pirical underpinnings suggest that knowledge, practices and awareness of safety precautions are uncharacteristically poor among laboratory workers. As such, their demonstration of safety-related attitudes and practices have remained questionable. This paper, thus presents a systematic search of the literature on laboratory workers’ safety-related knowledge, attitudes, and practices. Specifically, literature published between 2007 and 2017 that characteristically attempted to evaluate knowledge, attitudes and practices among laboratory workers on Occupational Safety and Health were reviewed. Evidently, results from the review indicate poor knowledge, attitude and practice among the laboratory workers. It is critical that strategies be put in place by the management of the health facilities to institute and undertake activities in the form of training, improved safety management practices, organizational commitment and improved safety culture.

Matched MeSH terms: Laboratories
Fulltext Misleading free thyroxine (FT4): a case report

Nurul Hidayah Hashim, Intan Nureslyna Samsudin, Ana Dalila Masiman, Subashini C. Thambiah

Malaysian Journal of Medicine and Health Sciences, 2020;16(2):320-322.
MyJurnal

Interpretation of thyroid function test (TFT) is often straightforward but in certain scenarios, discordance between the clinical impression and the laboratory results exists. A 50-year-old woman with a ten years history of hypothyroidism on levothyroxine presented with a recent notable change in TFT [elevated free thyroxine (FT4) and thyroid-stimulat- ing hormone (TSH)], in an otherwise clinically euthyroid and previously stable TFT, leading to levothyroxine being withheld. This case report highlights the possibility of assay interference as a cause of discordant TFT. It also draws the importance of close collaboration between clinicians and the laboratory to avoid unnecessary investigations and inappropriate management of such a case.

Matched MeSH terms: Laboratories
Fulltext Improvement of urgent tests laboratory turnaround time through laboratory lean management

Salbiah Isa, Rohayu Hami, Hanita Hashim, Mohd Nizam S., Harani MS., Sairi S., et al.

Malaysian Journal of Medicine and Health Sciences, 2020;16(102):15-21.
MyJurnal

Introduction: Laboratory turnaround time (LTAT) is considered a reliable indicator of the quality and efficiency of a laboratory’s service. LTAT achievement, particularly of urgent tests, remains unsatisfactory and challenging in many clinical laboratories especially in tertiary health care centres with high workload and restricted resources. The unresolved issue of unsatisfactory urgent renal profile (RP) LTAT below the standard performance goal prompted our interest to improve laboratory’s handling of urgent test request. We thus implemented the Lean principle in the management of urgent test requests using urgent RP as the test model. Methods: The implementation of laboratory Lean involved 4 steps process; (1) Development of burning platform for change (2) Identification of waste (3) Plan- ning and implementation of control measures (4) Measuring, monitoring, and sustaining the improvement. Urgent RP LTAT and the percentage of the request met the time requirement determined based on the data extracted from laboratory information system (LIS) before and after the implementation of Lean was compared to assess the effec- tiveness. Results: Urgent RP LTAT after the implementation of Lean was reduced i.e 35 min (before) vs 31 min (after), with the percentage of LTAT met the time requirement was significantly increased above the set target i.e 82.8% (before) to 93.5% (after) with P-value = 0.001. Conclusion: Implementation of innovation using Lean management has significantly improved urgent RP LTAT achievement, thus optimised urgent test management in our Chemical Pathology laboratory. Lean is a strongly recommended strategy to improve urgent test LTAT especially in laboratories with restricted resources.

Matched MeSH terms: Laboratories
Fulltext Introducing a technique in sustaining adult worker bees of Heterotrigona itama (Cockerell, 1918) in laboratory to facilitate future health research on Kelulut honey

Syazana Jumaan, Jahangir Kamaldin, Rosliza Jajuli, Izfa Riza Hazmi

Malaysian Journal of Medicine and Health Sciences, 2020;16(102):22-30.
MyJurnal

Introduction: The study is introducing a laboratory technique to sustain the longevity of Heterotrigona itama sting- less bees collected from the farm in order to facilitate future health research on Kelulut honey. Methods: The worker bees were held in laboratory at 26 ± 2 oC, 57 ± 8 % relative humidity (RH) and 12:12 hours (light:dark period) in a cup covered with meshed cloth and installed with an inverted-wick system consists of a drinking straw with the bottom end loosely plugged with cotton wool. The artificial diet was pipetted into the straw to wet the cotton wool. The bees were divided into five diet groups, namely a) unfed - control, b) distilled water, c) purified tap water, d) non-carbonated isotonic drink or e) 5% honey solution. Feeding activity and survival of worker bees were observed daily. Results: The worker bees are seen to frequent and lick the cotton wool wetted with artificial diets. Comparison between the artificial diets, Kaplan-Meier statistical analysis showed that the 5% honey solution and non-carbonated isotonic drink have significantly (P < 0.05) extended the longevity of the worker bees with 50% survival probability at least 8 days. When the similar holding and feeding technique used for the bees from commercial farms, the 50% survival probability was extended to 14 days. Conclusion: The inverted-wick system with the use of 5% honey solu- tion or isotonic drink as the artificial diet is capable to hold the H. itama worker bees at least for a week with survival above 50% for laboratory experiments.

Matched MeSH terms: Laboratories
Fulltext Bioaerosol levels in indoor air of animal house and hospital laboratories; a comparison with library and administrative offices

Siti Marwanis Anua, Nur Fatin Haris, Nurzafirah Mazlan

Malaysian Journal of Medicine and Health Sciences, 2020;16(101):94-100.
MyJurnal

Introduction: This study reported the concentration of bacterial and fungal bioaerosol at an animal house and hospi- tal laboratories with the aim to compare the concentration levels at library and administrative offices. The bioaerosol levels between mid-shift (afternoon) were also compared to the concentration measured during pre-shift (morning). Methods: The NIOSH 0800 method utilising microbiological air sampler collecting airborne bacterial and fungal samples via impaction technique on Nutrient agar (NA) and Sabouraud Dextrouse agar (SDA) as culture medium, respectively. Sampling was done twice daily; before (pre-shift) and during working (mid-shift) hour. Results: The highest bacteria and fungi concentration was recorded at the animal house with median concentration of 2477 CFU/ m3 (IQR=121-2477) and 791 CFU/m3 (IQR = 379-2081), respectively. Higher-risked workplaces such as animal house and hospital laboratories have significantly higher bioaerosol concentrations compared to control workplaces such as library and administrative offices (p

Matched MeSH terms: Laboratories, Hospital
Replicating remembering "remembering"

Janssen SMJ, Anthony K, Chang CYM, Choong EL, Neoh JY, Lim A

Memory, 2020 Dec 31.
PMID: 33382346 DOI: 10.1080/09658211.2020.1868525

When examining spontaneously recovered memories of childhood sexual abuse, victims report that there had been periods in which they had forgotten the abuse. However, there are sometimes people with whom the victim had spoken about the abuse during the period in which the victim had supposedly forgotten the abuse, suggesting the victim had not forgotten the abuse but the prior recall of the abuse. The underestimation of previous knowledge is termed the forgot-it-all-along effect. The goal of the present study was replicating the results of a laboratory study that had provided a theoretical understanding for the forgot-it-all-along effect by showing that people have difficulties remembering "remembering" when the memory had previously been recalled in a different context. The effect was replicated by using the same neutral context sentences, suggesting the finding was robust. We also extended the experimental design by using positive and negative context sentences, but it did not become smaller when the positive sentences provided the different context or larger when the negative sentences provided the different context. Although the sample sizes were sufficiently large to provide statistical power for the forgot-it-all-along effect, they may not have been sufficiently large to observe the moderation effects of emotional context.

Matched MeSH terms: Laboratories
Qualitative and Quantitative Analysis of Mycotoxins

Rahmani A, Jinap S, Soleimany F

Compr Rev Food Sci Food Saf, 2009 Jul;8(3):202-251.
PMID: 33467794 DOI: 10.1111/j.1541-4337.2009.00079.x

Mycotoxin toxicity occurs at very low concentrations, therefore sensitive and reliable methods for their detection are required. Consequently, sampling and analysis of mycotoxins is of critical importance because failure to achieve a suitable verified analysis can lead to unacceptable consignments being accepted or satisfactory shipments unnecessarily rejected. The general mycotoxin analyses carried out in laboratories are still based on physicochemical methods, which are continually improved. Further research in mycotoxin analysis has been established in such techniques as screening methods with TLC, GC, HPLC, and LC-MS. In some areas of mycotoxin method development, immunoaffinity columns and multifunctional columns are good choices as cleanup methods. They are appropriate to displace conventional liquid-liquid partitioning or column chromatography cleanup. On the other hand, the need for rapid yes/no decisions for exported or imported products has led to a number of new screening methods, mainly, rapid and easy-to-use test kits based on immuno-analytical principles. In view of the fact that analytical methods for detecting mycotoxins have become more prevalent, sensitive, and specific, surveillance of foods for mycotoxin contamination has become more commonplace. Reliability of methods and well-defined performance characteristics are essential for method validation. This article covers some of the latest activities and progress in qualitative and quantitative mycotoxin analysis.

Matched MeSH terms: Laboratories
Fulltext Surface-Mounted Bare and Packaged Fiber Bragg Grating Sensors for Measuring Rock Strain in Uniaxial Testing

Isah BW, Mohamad H

Sensors (Basel), 2021 Apr 22;21(9).
PMID: 33922008 DOI: 10.3390/s21092926

The paper explores the possibility of using high-resolution fiber Bragg grating (FBG) sensing technology for on-specimen strain measurement in the laboratory. The approach provides a means to assess the surface deformation of the specimen, both the axial and radial, through a chain of FBG sensor (C-FBG), in a basic setup of a uniaxial compression test. The method is cost-effective, straightforward and can be commercialized. Two C-FBG; one was applied directly to the sample (FBGBare), and the other was packaged (FBGPack) for ease of application. The approach measures the local strain with high-resolution and accuracy levels that match up to the existing local strain measuring sensors. The approach enables the evaluation of small-strain properties of the specimen intelligently. The finite element model analysis deployed has proven the adaptability of the technique for measuring material deformation. The adhesive thickness and packaging technique have been shown to influence the sensitivity of the FBG sensors. Owing to the relative ease and low-cost of instrumentation, the suggested method has a great potential to be routinely applied for elemental testing in the laboratory.

Matched MeSH terms: Laboratories
Potent allelopathy and non-PSTs, non-spirolides toxicity of the dinoflagellate Alexandrium leei to phytoplankton, finfish and zooplankton observed from laboratory bioassays

Shang L, Xu Y, Leaw CP, Lim PT, Wang J, Chen J, et al.

Sci Total Environ, 2021 Aug 01;780:146484.
PMID: 33774286 DOI: 10.1016/j.scitotenv.2021.146484

The dinoflagellate genus Alexandrium has been well known for causing paralytic shellfish poisoning (PSP) worldwide. Several non-PSP toxin-producing species, however, have shown to exhibit fish-killing toxicity. Here, we report the allelopathic activity of Alexandrium leei from Malaysia to other algal species, and its toxicity to finfish and zooplankton, via laboratory bioassays. Thirteen microalgal species that co-cultured with Al. leei revealed large variability in the allelopathic effects of Al. leei on the test algae, with the growth inhibition rates ranging from 0 to 100%. The negative allelopathic effects of Al. leei on microalgae included loss of flagella and thus the motility, damages of chain structure, deformation in cell morphology, and eventually cell lysis. The finfish experienced 100% mortality within 24 h exposed to the live culture (2000-6710 cells·mL-1), while the rotifer and brine shrimp exhibited 96-100% and 90-100% mortalities within 48 h when exposed to 500-6000 cells·mL-1 of Al. leei. The mortality of the test animals depended on the Al. leei cell density exposed, leading to a linear relationship between mortality and cell density for the finfish, and a logarithmic relationship for the two zooplankters. When exposed to the treatments using Al. leei whole live culture, cell-free culture medium, extract of algal cells in the f/2-Si medium, extract of methanol, and the re-suspended freeze-and-thaw algal cells, the test organisms (Ak. sanguinea and rotifers) all died at the cell density of 8100 cells·mL-1 within 24 h. Toxin analyses by HILIC-ESI-TOF/MS and LC-ESI-MS/MS demonstrated that Al. leei did not produce PSP-toxins and 13-desmethyl spirolide C. Overall, our findings demonstrated potent allelopathy and toxicity of Al. leei, which do not only pose threats to the aquaculture industry, fisheries, and marine ecosystems but may also play a part role in the population dynamics and bloom formation of this species.

Matched MeSH terms: Laboratories

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