Displaying publications 2421 - 2440 of 5752 in total

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  1. Haron NH, Md Toha Z, Abas R, Hamdan MR, Azman N, Khairuddean M, et al.
    Asian Pac J Cancer Prev, 2019 Feb 26;20(2):601-609.
    PMID: 30806066
    Objective: This study was conducted to investigate the antiproliferative activity of extracts of Clinacanthus nutans
    leaves against human cervical cancer (HeLa) cells. Methods: C. nutans leaves were subjected to extraction using 80%
    methanol or water. The methanol extract was further extracted to obtain hexane, dichloromethane (DCM), and aqueous
    fractions. The antiproliferative activity of the extracts against HeLa cells was determined. The most cytotoxic extract
    was furthered analyzed by apoptosis and cell cycle assays, and the phytochemical constituents were screened by gas
    chromatography-mass spectrometry (GC-MS). Results: All of the extracts were antiproliferative against HeLa cells, and
    the DCM fraction had the lowest IC50 value of 70 μg/mL at 48 h. Microscopic studies showed that HeLa cells exposed
    to the DCM fraction exhibited marked morphological features of apoptosis. The flow cytometry study also confirmed
    that the DCM fraction induced apoptosis in HeLa cells, with cell cycle arrest at the S phase. GC-MS analysis revealed
    the presence of at least 28 compounds in the DCM fraction, most of which were fatty acids. Conclusion: The DCM
    fraction obtained using the extraction method described herein had a lower IC50 value than those reported in previous
    studies that characterized the anticancer activity of C. nutans against HeLa cells.
  2. Leong SS, Wong JHD, Md Shah MN, Vijayananthan A, Jalalonmuhali M, Ng KH
    Ultrasound Med Biol, 2019 06;45(6):1417-1426.
    PMID: 30962016 DOI: 10.1016/j.ultrasmedbio.2019.01.024
    The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for 51Cr-ethylenediaminetetraacetic acid GFR and 99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = -0.635, p < 0.0001) and left (r = -0.817, p < 0.0001) kidneys. Positive correlations between left renal cortical thickness (r = 0.381, p = 0.04) and left kidney volume (r = 0.356, p = 0.019) with GFR were reported. SWE correctly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating characteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.252-0.415). The cutoff value of ≥5.52 kPa suggested a kidney function ≤60 mL/min/1.73 m2 (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney.
  3. Ibau C, Md Arshad MK, Gopinath SCB, Nuzaihan M N M, M Fathil MF, Estrela P
    Biosens Bioelectron, 2019 Jul 01;136:118-127.
    PMID: 31054519 DOI: 10.1016/j.bios.2019.04.048
    A simple, single-masked gold interdigitated triple-microelectrodes biosensor is presented by taking the advantage of an effective self-assembled monolayer (SAM) using an amino-silanization technique for the early detection of a prostate cancer's biomarker, the prostate-specific antigen (PSA). Unlike most interdigitated electrode biosensors, biorecognition happens in between the interdigitated electrodes, which enhances the sensitivity and limit of detection of the sensor. Using the Faradaic mode electrochemical impedance spectroscopy (EIS) technique to quantify the PSA antigen, the developed sensing platform demonstrates a logarithmic detection of PSA ranging from 0.5 ng/ml to 5000 ng/ml, an estimated LOD down to 0.51 ng/ml in the serum, and a good sensor's reproducibility. The sensor's detection range covers the clinical threshold value at 4 ng/ml and the crucial diagnosis 'grey zone' of 4-10 ng/ml of PSA in serum for an accurate cancer diagnosis. The selectivity test revealed an excellent discrimination of other competing proteins, with a recorded detection signals at 5 ng/ml PSA as high as 7-fold increase versus the human serum albumin (HSA) and 8-fold increase versus the human glandular kallikrein 2 (hK2). The stability test showed an acceptable stability of the aptasensor recorded at six (6) days before the detection signal started degrading below 10% of the peak detection value. The developed sensing scheme is proven to exhibit a great potential as a portable prostate cancer biosensor, also as a universal platform for bio-molecular sensing with the versatility to implement nanoparticles and other surface chemistry for various applications.
  4. Ahmad Zaiki FW, Md Dom S, Abdul Razak HR, Hassan HF
    Quant Imaging Med Surg, 2013 Oct;3(5):262-8.
    PMID: 24273744 DOI: 10.3978/j.issn.2223-4292.2013.10.05
    Prenatal Ultrasound (US) is commonly used as a routine procedure on pregnant women. It is generally perceived as a safe procedure due to the use of non-ionizing radiation. However, the neurotoxicity of diagnostic prenatal US was detected to have a correlation with high susceptibility to early developing fetus. This research involved in vivo experimental model by using 3(rd) trimester pregnant Oryctolagus cuniculus and exposing them to US exposures for 30, 60, and 90 minutes at their gestational day (GD) 28-29. The output power and intensities, spatial peak temporal average intensity (ISPTA) of US were varied from 0.4 to 0.7 W and 0.13 to 0.19 W/cm(2) respectively were tested initially in free-field, water. Haematological analysis was carried out to detect any changes in blood constituents. Statistically significant differences were detected in red blood cell (RBC) count (P<0.001), haemoglobin (Hb) concentration (P<0.001) and also platelet (PLT) count (P<0.001) in newborn of Oryctolagus cuniculus. These findings indicate the possibility of US heating in causing defects on studied animal.
  5. Mohd Fauzi Yap MFB, Mohd Zain A, Tumain NR, Palaniappan S, Nasaruddin RA, Md Din N
    Ocul Immunol Inflamm, 2020 Sep 24.
    PMID: 32967510 DOI: 10.1080/09273948.2020.1800050
    A 45-year-old man was diagnosed with diffuse large B-cell lymphoma stage IV which was confirmed by celiac lymph node biopsy. He subsequently completed six cycles of R-CHOP chemotherapy. Six months later, he presented with panuveitis OU with positive relative afferent pupillary defect OD. OCT revealed hyper-reflective lesions and irregularity of the retinal pigment epithelium OU. Fundus fluorescein angiogram shows hyper-auto fluorescence and granular changes on the retina. A month later, he developed swollen optic disc OD and hemorrhagic retinitis OU and treated as presumed CMV retinitis. Anti-TB was started after a positive Mantoux test. He finally consented for a vitreous biopsy which showed atypical lymphoid cells highly suggestive for vitreoretinal lymphoma and subsequently received intravitreal methotrexate OU.

    CONCLUSION: Optic nerve infiltration in systemic metastatic retinal lymphoma may have initial occult signs but with profound visual loss. Ocular infections like CMV retinitis and tuberculosis may mask and delay the diagnosis in immunocompromised patients.

  6. Ahmad Saffian H, Talib MA, Lee SH, Md Tahir P, Lee CH, Ariffin H, et al.
    Polymers (Basel), 2020 Aug 15;12(8).
    PMID: 32824275 DOI: 10.3390/polym12081833
    Mechanical strength, thermal conductivity and electrical breakdown of polypropylene/lignin/kenaf core fiber (PP/L/KCF) composite were studied. PP/L, PP/KCF and PP/L/KCF composites with different fiber and lignin loading was prepared using a compounding process. Pure PP was served as control. The results revealed that tensile and flexural properties of the PP/L/KCF was retained after addition of lignin and kenaf core fibers. Thermal stability of the PP composites improved compared to pure PP polymer. As for thermal conductivity, no significant difference was observed between PP composites and pure PP. However, PP/L/KCF composite has higher thermal diffusivity. All the PP composites produced are good insulating materials that are suitable for building. All PP composites passed withstand voltage test in air and oil state as stipulated in IEC 60641-3 except PP/L in oil state. SEM micrograph showed that better interaction and adhesion between polymer matrix, lignin and kenaf core fibers was observed and reflected on the better tensile strength recorded in PP/L/KCF composite. This study has successfully filled the gap of knowledge on using lignin and kenaf fibers as PP insulator composite materials. Therefore, it can be concluded that PP/Lignin/KCF has high potential as an insulating material.
  7. Girei SH, Lim HN, Ahmad MZ, Mahdi MA, Md Zain AR, Yaacob MH
    Sensors (Basel), 2020 Aug 21;20(17).
    PMID: 32825539 DOI: 10.3390/s20174713
    The need for environmental protection and water pollution control has led to the development of different sensors for determining many kinds of pollutants in water. Ammonia nitrogen presence is an important indicator of water quality in environmental monitoring applications. In this paper, a high sensitivity sensor for monitoring ammonia nitrogen concentration in water using a tapered microfiber interferometer (MFI) as a sensor platform and a broad supercontinuum laser as the light source is realized. The MFI is fabricated to the waist diameter of 8 µm producing a strong interference pattern due to the coupling of the fundamental mode with the cladding mode. The MFI sensor is investigated for a low concentration of ammonia nitrogen in water in the wide wavelength range from 1500-1800 nm with a high-power signal provided by the supercontinuum source. The broad source allows optical sensing characteristics of the MFI to be evaluated at four different wavelengths (1505, 1605, 1705, and 1785 nm) upon exposure towards various ammonia nitrogen concentrations. The highest sensitivity of 0.099 nm/ppm that indicates the wavelength shift is observed at 1785 nm operating wavelength. The response is linear in the ammonia nitrogen range of 5-30 ppm with the best measurement resolution calculated to be 0.5 ppm. The low concentration ammonia nitrogen detected by the MFI in the unique infrared region reveals the potential application of this optical fiber-based sensor for rivers and drinking water monitoring.
  8. Yap KH, Yee GS, Candasamy M, Tan SC, Md S, Abdul Majeed AB, et al.
    Biomolecules, 2020 09 24;10(10).
    PMID: 32987623 DOI: 10.3390/biom10101360
    Catalpol was tested for various disorders including diabetes mellitus. Numerous molecular mechanisms have emerged supporting its biological effects but with little information towards its insulin sensitizing effect. In this study, we have investigated its effect on skeletal muscle mitochondrial respiration and insulin signaling pathway. Type-2 diabetes (T2DM) was induced in male C57BL/6 by a high fat diet (60% Kcal) and streptozotocin (50 mg/kg, i.p.). Diabetic mice were orally administered with catalpol (100 and 200 mg/kg), metformin (200 mg/kg), and saline for four weeks. Fasting blood glucose (FBG), HbA1c, plasma insulin, oral glucose tolerance test (OGTT), insulin tolerance test (ITT), oxygen consumption rate, gene (IRS-1, Akt, PI3k, AMPK, GLUT4, and PGC-1α) and protein (AMPK, GLUT4, and PPAR-γ) expression in muscle were measured. Catalpol (200 mg/kg) significantly (p < 0.05) reduced the FBG, HbA1C, HOMA_IR index, and AUC of OGTT whereas, improved the ITT slope. Gene (IRS-1, Akt, PI3k, GLUT4, AMPK, and PGC-1α) and protein (AMPK, p-AMPK, PPAR-γ and GLUT4) expressions, as well as augmented state-3 respiration, oxygen consumption rate, and citrate synthase activity in muscle was observed in catalpol treated mice. The antidiabetic activity of catalpol is credited with a marked improvement in insulin sensitivity and mitochondrial respiration through the insulin signaling pathway and AMPK/SIRT1/PGC-1α/PPAR-γ activation in the skeletal muscle of T2DM mice.
  9. Voon NS, Lau FN, Zakaria R, Md Rani SA, Ismail F, Manan HA, et al.
    Cancer Radiother, 2021 Feb;25(1):62-71.
    PMID: 33414057 DOI: 10.1016/j.canrad.2020.07.008
    PURPOSE: Nasopharyngeal carcinoma (NPC) radiotherapy (RT) irradiates parts of the brain which may cause cerebral tissue changes. This study aimed to systematically review the brain microstructure changes using MRI-based measures, diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI) and voxel-based morphometry (VBM) and the impact of dose and latency following RT.

    METHODS: PubMed and Scopus databases were searched based on PRISMA guideline to determine studies focusing on changes following NPC RT.

    RESULTS: Eleven studies fulfilled the inclusion criteria. Microstructural changes occur most consistently in the temporal region. The changes were correlated with latency in seven studies; fractional anisotropy (FA) and gray matter (GM) volume remained low even after a longer period following RT and areas beyond irradiation site with reduced FA and GM measures. For dosage, only one study showed correlation, thus requiring further investigations.

    CONCLUSION: DTI, DKI and VBM may be used as a surveillance tool in detecting brain microstructural changes of NPC patients which correlates to latency and brain areas following RT.

  10. Mahmud H, Ismail A, Abdul Rahim R, Low KO, Md Illias R
    J Biotechnol, 2019 Apr 20;296:22-31.
    PMID: 30878516 DOI: 10.1016/j.jbiotec.2019.02.013
    In previous studies of Lactococcus lactis, the levels of proteins secreted using heterologous signal peptides were observed to be lower than those obtained using the signal peptide from Usp45, the major secreted lactococcal protein. In this study, G1 (the native signal peptide of CGTase) and the signal peptide M5 (mutant of the G1 signal peptide) were introduced into L. lactis to investigate the effect of signal peptides on lactococcal protein secretion to improve secretion efficiency. The effectiveness of these signal peptides were compared to the Usp45 signal peptide. The highest secretion levels were obtained using the G1 signal peptide. Sequence analysis of signal peptide amino acids revealed that a basic N-terminal signal peptide is not absolutely required for efficient protein export in L. lactis. Moreover, the introduction of a helix-breaking residue in the H-region of the M5 signal peptide caused a reduction in the signal peptide hydrophobicity and decreased protein secretion. In addition, the optimization of cultivation conditions for recombinant G1-CGTase production via response surface methodology (RSM) showed that CGTase activity increased approximately 2.92-fold from 5.01 to 16.89 U/ml compared to the unoptimized conditions.
  11. Md Din MF, Lee YY, Ponraj M, Ossen DR, Iwao K, Chelliapan S
    J Therm Biol, 2014 Apr;41:6-15.
    PMID: 24679966 DOI: 10.1016/j.jtherbio.2014.01.004
    Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity.
  12. Fateh AH, Mohamed Z, Chik Z, Alsalahi A, Md Zin SR, Alshawsh MA
    Chem Biol Interact, 2019 May 01;304:28-42.
    PMID: 30807743 DOI: 10.1016/j.cbi.2019.02.016
    Verbena officinalis is widely used by women for maintaining general health and treating various gynaecological disorders during pregnancy. A case report has indicated that the consumption of V. officinalis induced an abortifacient effect. Hence, this study aimed to investigate the prenatal developmental toxicity of this plant according to OECD guideline (no. 414). A total of 50 pregnant female rats (dams) were distributed into five groups (n = 10); 500 mg/kg 1000 mg/2000 mg/kg and 3000 mg/kg of V. offcinalis extracts and the fifth group served as a normal control. All dams received their respective oral single daily treatment from the 6th to the 20th day of gestation. Maternal clinical toxicity signs, body weight and weight gain were recorded. Caesarean sections were performed on day 21 to evaluate embryo-foetal developmental toxicity. For dams, ovaries were harvested and weighed. The number of corpora lutea, implantation sites, and resorptions were recorded. No mortality was observed in dams, but their body weight gain was significantly reduced particularly in dams treated with 2000 and 3000 mg/kg V. officinalis. Asymmetrical distribution of implantation sites and embryos were observed. Embryo-fetotoxicity retardation was observed as evident by the decrease in foetal weight, head cranium, tail length, and higher incidence in the pre-and post-implantation loss. Some foetal skeleton abnormalities such as incomplete ossification of skull, sternebrae, and metatarsal bones were observed in foetuses of the 2000 and 3000 mg/kg V. officinalis-treated dams. LC/MS analysis identified the major constituents including geniposidic acid, tuberonic acid glucoside, luteolin 7, 3'-digalacturonide, iridotrial and apigenin. The glycosylated flavonoids such as apigenin and luteolin could be responsible for the reported prenatal developmental toxicity. In conclusion, the use of V. officinalis during pregnancy is not safe indicating evidence-based toxic effects on the reproductive performance of dams and dose-dependent risk potentials to the foetuses.
  13. Shahimi S, Lamri MF, Abd Mutalib S, Mohd Khalid R, Md Tab M, Khairuddin F
    Food Chem, 2021 Sep 01;355:129586.
    PMID: 33773458 DOI: 10.1016/j.foodchem.2021.129586
    In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.
  14. Amri MR, Guan CT, Osman Al-Edrus SS, Md Yasin F, Mohamad SF
    Polymers (Basel), 2021 Apr 30;13(9).
    PMID: 33946517 DOI: 10.3390/polym13091460
    The objective of this work was to study the influence of cellulose nanofibrils (CNF) on the physical, mechanical, and thermal properties of Jatropha oil-based waterborne polyurethane (WBPU) nanocomposite films. The polyol to produce polyurethane was synthesized from crude Jatropha oil through epoxidation and ring-opening method. The chain extender, 1,6-hexanediol, was used to improve film elasticity by 0.1, 0.25, and 0.5 wt.% of CNF loading was incorporated to enhance film performance. Mechanical performance was studied using a universal test machine as specified in ASTM D638-03 Type V and was achieved by 0.18 MPa at 0.5 wt.% of CNF. Thermal gravimetric analysis (TGA) was performed to measure the temperature of degradation and the chemical crosslinking and film morphology were studied using Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The results showed that when the CNF was incorporated, it was found to enhance the nanocomposite film, in particular its mechanical and thermal properties supported by morphology. Nanocomposite film with 0.5 wt.% of CNF showed the highest improvement in terms of tensile strength, Young's modulus, and thermal degradation. Although the contact angle decreases as the CNF content increases, the effect on the water absorption of the film was found to be relatively small (<3.5%). The difference between the neat WPBU and the highest CNF loading film was not more than 1%, even after 5 days of being immersed in water.
  15. Balami AD, Md Said S, Mohd Zulkefli NA, Bachok N, Audu B
    BMC Pregnancy Childbirth, 2020 Nov 25;20(1):726.
    PMID: 33238901 DOI: 10.1186/s12884-020-03388-8
    BACKGROUND: Studies on uptake of first dose of intermittent preventive treatment in pregnancy (IPTp) are lacking, despite it being a predictor of subsequent doses. This study aimed at assessing the determinants of uptake of first dose of IPTp among pregnant women at the State Specialist Hospital, Maiduguri.

    METHODS: A cross-sectional study was conducted, in which respondents were selected using a systematic random sampling method, and structured questionnaires were used to obtain information from them. Chi-squared test was used to determine factors associated with uptake of first IPTp dose, while a further multivariate logistic regression was performed to determine its predictors.

    RESULTS: Three hundred and eighty respondents answered the survey, whose ages ranged from 15 to 45 years, and 86.8% were multigravid. Sixty five percent of them were aware of IPTp, and 34.7% believed that IPTp could be harmful to their pregnancies. Over a half of the respondents (52.9%) believed that taking all their IPTp medicines was very good for their pregnancies, while 45.0% felt that taking their IPTp medicines was very pleasant. Only two respondents (0.5%) stated that it was very untrue that their significant others thought that they should take all their IPTp medicines. Half of the respondents said it was very easy for them to take all their IPTp medicines even if they were experiencing mild discomforts while taking them. Less than a half (42.37%) had received their first dose of IPTp. In bivariate as well as multivariate analysis, only higher level of knowledge was significantly associated with uptake of first IPTp dose. Those with better knowledge of IPTp were about twice more likely to have taken their first dose of IPTp, compared to those with lower knowledge of IPTp (AOR = 1.85; 95% CI: 1.17-2.92).

    CONCLUSIONS: Knowledge of IPTp as well as its uptake, were sub-optimal in this study. Since knowledge of IPTp significantly predicts uptake of the first dose of IPTp, there is the need to implement health education campaigns to raise the awareness of pregnant women and their families on the need to receive and comply with it.

  16. Ahmad Sabri NS, Mohd Zulkeflle SN, Yusof N, Md Akhir FN, Othman N, Zakaria Z, et al.
    Microbiol Resour Announc, 2021 May 06;10(18).
    PMID: 33958405 DOI: 10.1128/MRA.00332-21
    Staphylococcus spp. are Gram-positive bacteria that reside within the normal microbiota of humans and animals but pose a health threat as reservoirs of antimicrobial resistance genes. Here, we present the draft genome sequences of three Staphylococcus sp. strains isolated from hospital wastewater in Malaysia that demonstrated resistance to multiple antibiotics.
  17. Md Noh MF, Gunasegavan RD, Mustafa Khalid N, Balasubramaniam V, Mustar S, Abd Rashed A
    Molecules, 2020 Oct 06;25(19).
    PMID: 33036314 DOI: 10.3390/molecules25194567
    Food composition database (FCD) provides the nutritional composition of foods. Reliable and up-to date FCD is important in many aspects of nutrition, dietetics, health, food science, biodiversity, plant breeding, food industry, trade and food regulation. FCD has been used extensively in nutrition labelling, nutritional analysis, research, regulation, national food and nutrition policy. The choice of method for the analysis of samples for FCD often depends on detection capability, along with ease of use, speed of analysis and low cost. Sample preparation is the most critical stage in analytical method development. Samples can be prepared using numerous techniques; however it should be applicable for a wide range of analytes and sample matrices. There are quite a number of significant improvements on sample preparation techniques in various food matrices for specific analytes highlighted in the literatures. Improvements on the technology used for the analysis of samples by specific instrumentation could provide an alternative to the analyst to choose for their laboratory requirement. This review provides the reader with an overview of recent techniques that can be used for sample preparation and instrumentation for food analysis which can provide wide options to the analysts in providing data to their FCD.
  18. Supahiah P, Bin Ahmad NA, Teh WM, Bt Abd Jalil NF, Md Din N
    Cureus, 2021 Jun;13(6):e16071.
    PMID: 34367742 DOI: 10.7759/cureus.16071
    Trichophyton species is a dermatophytic fungus commonly found in the skin, nails, hair, and other organic matters such as palm trees and soil. We report a rare case of a 23-year-old man who had a penetrating injury to the eye from the leaves of a palm tree and subsequently developed exogenous endophthalmitis. Culture from the vitreous tap revealed Trichophyton sp as the causative organism. Early vitrectomy and adequate intravitreal injection of amphotericin B resulted in good visual outcomes in an otherwise blinding condition. This is the first reported case of exogenous endophthalmitis secondary to Trichophyton species. Early diagnosis and prompt treatment may help improve visual outcomes.
  19. Islam MT, Moniruzzaman M, Alam T, Samsuzzaman M, Razouqi QA, Almutairi AF
    Sci Rep, 2021 Aug 19;11(1):16898.
    PMID: 34413377 DOI: 10.1038/s41598-021-96228-4
    In this paper, a meander-lines-based epsilon negative (ENG) metamaterial (MTM) with a high effective medium ratio (EMR) and near-zero refractive index (NZI) is designed and investigated for multiband microwave applications. The metamaterial unit cell is a modification of the conventional square split-ring resonator in which the meander line concept is utilized. The meander line helps to increase the electrical length of the rings and provides strong multiple resonances within a small dimension. The unit cell of proposed MTM is initiated on a low-cost FR4 substrate of 1.5 mm thick and electrical dimension of 0.06λ × 0.06λ, where wavelength, λ is calculated at the lowest resonance frequency (2.48 GHz). The MTM provides four major resonances of transmission coefficient (S21) at 2.48, 4.28, 9.36, and 13.7 GHz covering S, C, X, and Ku bands. It shows negative permittivity, near-zero permeability, and near-zero refractive index in the vicinity of these resonances. The equivalent circuit is designed and modeled in Advanced Design System (ADS) software. The simulated S21 of the MTM unit cell is compared with the measured one and both show close similarity. The array performance of the MTM is also evaluated by using 2 × 2, 4 × 4, and 8 × 8 arrays that show close resemblance with the unit cell. The MTM offers a high effective medium ratio (EMR) of 15.1, indicating the design's compactness. The frequency hopping characteristics of the proposed MTM is investigated by open and short-circuited the three outer rings split gaps by using three switches. Eight different combinations of the switching states provide eight different sets of multiband resonances within 2-18 GHz; those give the flexibility of using the proposed MTM operating in various frequency bands. For its small dimension, NZI, high EMR, and frequency hopping characteristics through switching, this metamaterial can be utilized for multiband microwave applications, especially to enhance the gain of multiband antennas.
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