Displaying publications 61 - 80 of 142 in total

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  1. Mohamad Shalan NA, Mustapha NM, Mohamed S
    Food Chem, 2016 Dec 01;212:443-52.
    PMID: 27374554 DOI: 10.1016/j.foodchem.2016.05.179
    Morinda citrifolia fruit, (noni), enhanced performances in athletes and post-menopausal women in clinical studies. This report shows the edible noni leaves water extract enhances performance in a weight-loaded swimming animal model better than the fruit or standardized green tea extract. The 4weeks study showed the extract (containing scopoletin and epicatechin) progressively prolonged the time to exhaustion by threefold longer than the control, fruit or tea extract. The extract improved (i) the mammalian antioxidant responses (MDA, GSH and SOD2 levels), (ii) tissue nutrient (glucose) and metabolite (lactate) management, (iii) stress hormone (cortisol) regulation; (iv) neurotransmitter (dopamine, noradrenaline, serotonin) expressions, transporter or receptor levels, (v) anti-inflammatory (IL4 & IL10) responses; (v) skeletal muscle angiogenesis (VEGFA) and (v) energy and mitochondrial biogenesis (via PGC, UCP3, NRF2, AMPK, MAPK1, and CAMK4). The ergogenic extract helped delay fatigue by enhancing energy production, regulation and efficiency, which suggests benefits for physical activities and disease recovery.
  2. Shalan NA, Mustapha NM, Mohamed S
    Nutrition, 2017 Jan;33:42-51.
    PMID: 27908549 DOI: 10.1016/j.nut.2016.08.006
    OBJECTIVE: Black tea and Nonileaf are among the dietary compounds that can benefit patients with bone resorption disorders. Their bone regeneration effects and their mechanisms were studied in estrogen-deficient rats.

    METHODS: Noni leaves (three doses) and black tea water extracts were fed to ovariectomized rats for 4 mo, and their effects (analyzed via mechanical measurements, micro-computed tomography scan, and reverse transcriptase polymerase chain reaction mRNA) were compared with Remifemin (a commercial phytoestrogen product from black cohosh).

    RESULTS: The water extracts (dose-dependently for noni leaves) increased bone regeneration biomarker (runt-related transcription factor 2, bone morphogenetic protein 2, osteoprotegerin, estrogen receptor 1 [ESR1], collagen type I alpha 1A) expressions and reduced the inflammatory biomarkers (interleukin-6, tumor necrosis factor-α, nuclear factor [NF]-κB, and receptor activator of NF-κB ligand) mRNA expressions/levels in the rats. The extracts also improved bone physical and mechanical properties. The extracts demonstrated bone regeneration through improving bone size and structure, bone mechanical properties (strength and flexibility), and bone mineralization and density.

    CONCLUSIONS: The catechin-rich extract favored bone regeneration and suppressed bone resorption. The mechanisms involved enhancing osteoblast generation and survival, inhibiting osteoclast growth and activities, suppressing inflammation, improving bone collagen synthesis and upregulating ESR1 expression to augment phytoestrogenic effects. Estrogen deficiency bone loss and all extracts studied (best effect from Morinda leaf at 300 mg/kg body weight) mitigated the loss, indicating benefits for the aged and menopausal women.

  3. Che Ahmad Tantowi NA, Lau SF, Mohamed S
    Calcif. Tissue Int., 2018 10;103(4):388-399.
    PMID: 29808374 DOI: 10.1007/s00223-018-0433-1
    Osteoporosis (OP) and osteoarthritis (OA) are debilitating musculoskeletal diseases of the elderly. Ficus deltoidea (FD) or mistletoe fig, a medicinal plant, was pre-clinically evaluated against OP- and OA-related bone alterations, in postmenopausal OA rat model. Thirty twelfth-week-old female rats were divided into groups (n = 6). Four groups were bilateral ovariectomized (OVX) and OA-induced by intra-articular monosodium iodoacetate (MIA) injection into the right knee joints. The Sham control and OVX-OA non-treated groups were given deionized water. The three other OVX-OA groups were orally administered daily with FD extract (200, 400 mg/kg) or diclofenac (5 mg/kg) for 4 weeks. The rats' bones and blood were evaluated for protein and mRNA expressions of osteoporosis and inflammatory indicators, and micro-CT computed tomography for bone microstructure. The non-treated OVX-OA rats developed severe OP bone loss and bone microstructural damage in the subchondral and metaphyseal regions, supported by reduced serum bone formation markers (osteocalcin, osteoprotegerin) and increased bone resorption markers (RANKL and CTX-I). The FD extract significantly (p 
  4. Che Ahmad Tantowi NA, Hussin P, Lau SF, Mohamed S
    Menopause, 2017 Sep;24(9):1071-1080.
    PMID: 28640163 DOI: 10.1097/GME.0000000000000882
    OBJECTIVE: Ficus deltoidea Jack (mistletoe fig) is an ornamental plant found in various parts of the world and used as traditional herbal medicine in some countries. This study investigated the potential use of F deltoidea leaf extract to mitigate osteoarthritis (OA) in ovariectomized (estrogen-deficient postmenopausal model) rats and the mechanisms involved. Diclofenac was used for comparison.

    METHODS: Sprague-Dawley female rats (12 weeks old) were divided randomly into five groups (n = 6): healthy; nontreated OA; OA + diclofenac (5 mg/kg); OA + extract (200 mg/kg); and OA + extract (400 mg/kg). Two weeks after bilaterally ovariectomy, OA was induced by intra-articular injection of monosodium iodoacetate into the right knee joints. After 28 days of treatment, the rats were evaluated for knee OA via physical (radiological and histological observations), biochemical, enzyme-linked immunosorbent assay, and gene expression analysis, for inflammation and cartilage degradation biomarkers.

    RESULTS: The osteoarthritic rats treated with the extract, and diclofenac showed significant reduction of cartilage erosion (via radiological, macroscopic, and histological images) compared with untreated osteoarthritic rats. The elevated serum interleukin-1β, prostaglandin E2, and C-telopeptide type II collagen levels in osteoarthritic rats were significantly reduced by F deltoidea leaf extract comparable to diclofenac. The extract significantly down-regulated the interleukin-1β, prostaglandin E2 receptor, and matrix metalloproteinase-1 mRNA expressions in the osteoarthritic cartilages, similar to diclofenac.

    CONCLUSIONS: F deltoidea leaf extract mitigated postmenopausal osteoarthritic joint destruction by inhibiting inflammation and cartilage degradation enzymes, at an effective extract dose equivalent to about 60 mg/kg for humans. The main bioactive compounds are probably the antioxidative flavonoids vitexin and isovitexin.

  5. Bakar NA, Tengku Ibrahim TA, Mohamad Shalan NA, Mohamed S
    J Microsc Ultrastruct, 2016 08 21;5(2):70-81.
    PMID: 30023239 DOI: 10.1016/j.jmau.2016.08.001
    The edible red seaweed Kappaphycus alvarezii or Eucheuma cottonii is commercially cultivated in the pristine tropical seas for carrageenan production. The systemic, cellular, and molecular effects of E. cottonii 50% alcohol extract [seaweed E. cottonii ethanol extract (SECE)] on breast cancer were investigated in a rat model. Mammary tumor was induced by subcutaneously injecting LA7 cells in female rat mammary pads. After 2 weeks of cancer growth, the rats received oral administration of either SECE [150 mg/kg body weight (BW) and 300 mg/kg BW] or tamoxifen. Electron microscopy imaging results confirmed macrophage activity and hematoxylin and eosin staining indicated that tumor histopathological alterations were restored toward normal structures by the seaweed extract. The extract suppressed tumor development and modulated the immune responses. This was evidenced by the microscopic observations, the increased spleen weight, size, spleen CD19 B cells, and blood immunoglobulin G (IgG) levels. The extract also increased the circulating total white blood cells, lymphocytes, segmented neutrophils count, T cells (CD3), T-helper cells (CD4), cytotoxic T cell (CD8), and nuclear factor-kappa beta expressions. The extract enhanced cancer cell death, by upregulating the Birc5, Chk1, and p53 levels and downregulating the tumor growth cellular Mdm2 (transformed mouse 3T3 cell double minute 2) messenger RNA (mRNA) expression. The extract showed no toxicity at 150 mg/kg BW in rats. The lectin-rich SECE showed tumor suppression by enhancing immune responses and upregulating the cancer cell apoptosis mRNA expressions.
  6. Siti HN, Kamisah Y, Mohamed S, Jaarin K
    Appl Physiol Nutr Metab, 2019 04;44(4):373-380.
    PMID: 30216735 DOI: 10.1139/apnm-2018-0175
    The prolonged intake of diet containing repeatedly heated vegetable oil can cause hypertension in the long run.
    In this study, the effects of citrus leaf extract (CLE) supplementation on vascular reactivity, plasma nitrite, and aortic structure in hypertensive rats were investigated by the consumption of repeatedly heated vegetable oil [corrected]. Male Sprague Dawley rats (n = 56) were divided into 7 groups corresponding to the respective diets. For 16 weeks, 1 group was given standard rat chow (control) while other groups were given diets containing 15% w/w of palm oil, fresh palm oil (FPO), palm oil heated 5 times (5HPO), and palm oil heated 10 times (10HPO), with or without the incorporation of 0.15% w/w CLE (FPO+CLE, 5HPO+CLE, or 10HPO+CLE). Plasma nitrite levels were measured before and at 16 weeks of treatment. After 16 weeks, the rats were sacrificed and aortae were harvested for measuring vascular reactivity and for microscopic study. CLE supplementation had significantly reduced the loss of plasma nitrite and attenuated the vasoconstriction response to phenylephrine in the 5HPO group but not in the 10HPO group. However, CLE had no significant effect on the vasorelaxation response to acetylcholine and sodium nitroprusside. The elastic lamellae of tunica media in 5HPO, 10HPO, and 10HPO+CLE groups appeared disorganised and disrupted. Obtained findings suggested that CLE was able to enhance nitric oxide bioavailability that might dampen the vasoconstriction effect of phenylephrine.
  7. Mohamed S, Ismail Z, Shuib N, Ali NF
    Front Psychiatry, 2021;12:789554.
    PMID: 34938215 DOI: 10.3389/fpsyt.2021.789554
    Background: Medical students are not spared from the challenges related to the Covid-19 lockdown. The fear and uncertainties may lead to traumatic symptoms and test their resilience and sense of coping. Thus, this study aims to determine the prevalence of peri-traumatic distress symptoms and its association with the level of resilience and the coping strategies used during the lockdown among medical students. Materials and Methods: This was a cross-sectional online questionnaire survey involving medical students from a public university in Malaysia. It was conducted during the COVID-19 lockdown or Movement Control Order (MCO) where the students were asked to fill in the COVID-19 Peri-traumatic Distress Index (CPDI), Brief COPE Inventory, and Connor Davidson Resilience Scale (CDRS-25). Results: A total of 282 clinical and 172 pre-clinical medical students were involved. Peri-traumatic distress symptoms were reported by 27% out of the total students. This study found that those who were having peritraumatic distress symptoms were from the pre-clinical years, had poor internet access, as well as lower resilience levels, and used more dysfunctional coping strategies. Pre-clinical medical students with difficult internet access were eight times more likely to have peritraumatic distress symptoms. Conclusions: Given the high level of peri-traumatic distress symptoms reported by medical students during the lockdown, it is vital to identify the vulnerable students, assess their needs and risks to mental health problems during this challenging time as the pandemic is still ongoing with countries going in and out of lockdown depending on the cases at the time. The university administration for each University in Malaysia will need to have a clear academic guideline and policy as well as providing improved infrastructure to minimize the distress faced by medical students.
  8. Bokhari RA, Tantowi NACA, Lau SF, Mohamed S
    Inflammopharmacology, 2018 Aug;26(4):939-949.
    PMID: 29380171 DOI: 10.1007/s10787-017-0432-2
    The effect of Orthosiphon stamineus aqueous (OSA) extract against osteoarthritis (OA) was investigated in explant cartilage culture and in postmenopausal OA rat model. Female rats were bilaterally ovariectomized (OVX). Osteoarthritis was induced after surgical recovery, by intra-articular injection of monosodium iodoacetate (MIA) into the right knee. Rats were grouped (n = 8) into: healthy sham control; non-treated OA; OA + diclofenac (positive control 5 mg/kg); and two doses OSA (150-300 mg/kg). After 4 weeks' treatment, rats were evaluated for OA-related parameters and biomarkers. The OSA reduced proteoglycan and ROS release from the cartilage explants under inflammatory (IL-1b) conditions. In the OA-induced rats' cartilages, the OSA downregulated the mRNA expressions for IL-1β, IL-6, IL-10, TNF-α, NF-κβ, NOS2, PTGS2, PTGER2, ACAN, COL2A1, MMP1, MMP13, ADAMTS4, ADAMTS5 and TIMP1, mostly dose-dependently. The OSA reduced the OA rats' serum levels for PGE2, CTX-II, TNF-α, MMP1, MMP13, PIINP, OPG, RANKL, OC and BALP, but not dose-dependently. The OSA contained polyphenols and flavonoids (tetramethoxyflavone). The OSA alleviated articular cartilage degradation, inflammation, collagenase/aggrecanase activities, to improve joint and subchondral bone structure. O. stamineus mitigated osteoarthritis by downregulating inflammation, peptidases and aggrecanases, at a dose equivalent to about 30 mg/kg for humans.
  9. Nahar N, Mohamed S, Mustapha NM, Fong LS
    J Diabetes Metab Disord, 2022 Jun;21(1):1-11.
    PMID: 35673507 DOI: 10.1007/s40200-021-00905-0
    PURPOSE: Diabetes accelerates peripheral, distal symmetric polyneuropathy, small fiber predominant neuropathy, radiculoplexopathy, and autonomic neuropathy. This study investigated the neuroprotective effects of gallic acid and myricetin-rich Labisia pumila extract in a diabetic neuropathy rat model and evaluated the neuropathy correlationship with serum inflammatory biomarkers.

    METHODS: Thirty male rats were divided into 5 groups (n = 6), namely: healthy control; non-treated diabetic control; and diabetic-rats treated with 200 mg/kg metformin; Labisia pumila ethanol extract (LP) at 150 mg/kg or 300 mg/kg doses. Diabetes was induced by 60 mg streptozotocin /kg intraperitoneal injection. Rats were orally treated daily for ten weeks. Their fasting blood glucose (FBG), neurological functions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), biomarkers for inflammation and oxidative stress, the neuro-histopathological changes, and brain somatic index were measured.

    RESULTS: The extract significantly prevented abnormal increases in FBG and decreases in body weight gain. It attenuated behavioral dysfunctions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), systemic inflammation (serum TNF-α, prostaglandin-E2) oxidative tension (malondialdehyde), histological brain and sciatic nerve injuries in the diabetic-rats, better than Metformin.

    CONCLUSION: LP mitigated neural dysfunction better than metformin partly by amending diabetic systemic inflammation, oxidative tension, and diabetic abnormalities. The nerve injuries were strongly correlated to serum prostaglandin-E2, TNF-α levels, and walking functions. The motor function was correlated to sensory neuronal functions, inflammation, and oxidation. The sensory neuronal functions were more affected by TNF-α than prostaglandin-E2 or oxidation. Diabetic brain and sciatic nerve deteriorations were influenced by serum TNF-α, PGE2, and MDA levels.

    SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-021-00905-0.

  10. Motshakeri M, Ebrahimi M, Goh YM, Matanjun P, Mohamed S
    J Sci Food Agric, 2013 May;93(7):1772-8.
    PMID: 23208488 DOI: 10.1002/jsfa.5971
    BACKGROUND: Sargassum polycystum, a brown seaweed, contains various nutrients and bioactive compounds that have antioxidant and healing properties. The research hypothesises that antioxidants and pigments in dietary S. polycystum extracts can improve insulin sensitivity, blood sugar levels and blood lipid levels in a rat model of type 2 diabetes. The diabetes was induced by a high-sugar, high-fat diet for 16 weeks to enhance insulin resistance, followed by a low-dose intraperitoneal injection of streptozotocin (35 mg kg(-1) body weight). The doses of S. polycystum tested on diabetic rats were 150 and 300 mg kg(-1) body weight for the ethanolic extract or 150 and 300 mg kg(-1) for the water extract. Normal rats, untreated diabetic and metformin-treated diabetic rats (n = 6) were used as control.

    RESULTS: Both doses of the alcohol extract of S. polycystum and the 300 mg kg(-1) water extract, significantly reduced blood glucose and glycosylated haemoglobin (HbA1C ) levels. Serum total cholesterol, triglyceride levels and plasma atherogenic index were significantly decreased after 22 days treatment in all seaweed groups. Unlike metformin, S. polycystum did not significantly change plasma insulin in the rats, but increased the response to insulin.

    CONCLUSION: The consumption of either ethanolic or water extracts of S. polycystum dose dependently reduced dyslipidaemia in type 2 diabetic rats. S. polycystum is a potential insulin sensitiser, for a comestible complementary therapy in the management of type 2 diabetes which can help reduce atherogenic risk.

  11. Matanjun P, Mohamed S, Muhammad K, Mustapha NM
    J Med Food, 2010 Aug;13(4):792-800.
    PMID: 20482284 DOI: 10.1089/jmf.2008.1212
    This study was designed to investigate the comparative in vivo cardiovascular protective effects of red, green, and brown tropical seaweeds, namely, Kappaphycus alvarezii (or Eucheuma cottonii), Caulerpa lentillifera, and Sargassum polycystum, in rats fed on high-cholesterol/high-fat (HCF) diets. Male Sprague-Dawley rats (weighing 260-300 g) on the HCF diet had significantly increased body weight, plasma total cholesterol (TC), plasma low-density lipoprotein cholesterol (LDL-C), plasma triglycerides (TG), lipid peroxidation, and erythrocyte glutathione peroxidase (GSH-Px) and superoxide dismutase levels after 16 weeks. Supplementing 5% seaweeds to HCF diet significantly reduced plasma TC (-11.4% to -18.5%), LDL-C (-22% to -49.3%), and TG (-33.7% to -36.1%) levels and significantly increased HDL-C levels (16.3-55%). Among the seaweeds, S. polycystum showed the best anti-obesity and blood GSH-Px properties, K. alvarezii showed the best antihyperlipemic and in vivo antioxidation effects, and C. lentillifera was most effective at reducing plasma TC. All seaweeds significantly reduced body weight gain, erythrocyte GSH-Px, and plasma lipid peroxidation of HCF diet rats towards the values of normal rats.
  12. Tantowi NACA, Mohamed S, Lau SF, Hussin P
    Daru, 2020 Dec;28(2):443-453.
    PMID: 32388789 DOI: 10.1007/s40199-020-00343-y
    BACKGROUND: Osteoporotic-osteoarthritis is an incapacitating musculoskeletal illness of the aged.

    OBJECTIVES: The anti-inflammatory and anti-catabolic actions of Diclofenac were compared with apigenin-C-glycosides rich Clinacanthus nutans (CN) leaf extract in osteoporotic-osteoarthritis rats.

    METHODS: Female Sprague Dawley rats were randomized into five groups (n = 6). Four groups were bilateral ovariectomised for osteoporosis development, and osteoarthritis were induced by intra-articular injection of monosodium iodoacetate (MIA) into the right knee joints. The Sham group was sham-operated, received saline injection and deionized drinking water. The treatment groups were orally given 200 or 400 mg extract/kg body weight or 5 mg diclofenac /kg body weight daily for 28 days. Articular cartilage and bone changes were monitored by gross and histological structures, micro-CT analysis, serum protein biomarkers, and mRNA expressions for inflammation and catabolic protease genes.

    RESULTS: HPLC analysis confirmed that apigenin-C-glycosides (shaftoside, vitexin, and isovitexin) were the major compounds in the extract. The extract significantly and dose-dependently reduced cartilage erosion, bone loss, cartilage catabolic changes, serum osteoporotic-osteoarthritis biomarkers (procollagen-type-II-N-terminal-propeptide PIINP; procollagen-type-I-N-terminal-propeptide PINP; osteocalcin), inflammation (IL-1β) and mRNA expressions for nuclear-factor-kappa-beta NF-κβ, interleukin-1-beta IL-1β, cyclooxygenase-2; and matrix-metalloproteinase-13 MMP13 activities, in osteoporotic-osteoarthritis rats comparable to Diclofenac.

    CONCLUSION: This study demonstrates that apigenin-C-glycosides at 400 mg CN extract/kg (about 0.2 mg apigenin-equivalent/kg) is comparable to diclofenac in suppressing inflammation and catabolic proteases for osteoporotic-osteoarthritis prevention. Graphical abstract.

  13. Norhapifah H, Isa MR, Abdullah B, Mohamed S
    Int J Community Based Nurs Midwifery, 2024 Oct;12(4):243-253.
    PMID: 39411571 DOI: 10.30476/ijcbnm.2024.101509.2432
    BACKGROUND: Labour pain experienced by women during childbirth can significantly affect the mother's psychological condition and birthing process. This study aimed to determine the effect of shiatsu massage on pain and anxiety during labour.

    METHOD: This randomized controlled trial was conducted on 80 nulliparous pregnant women who gave birth in four low-risk maternity clinics in Samarinda, Indonesia, from February to May 2022. The women were randomized into intervention (N=40) and control (N=40) groups based on random allocation. Certified midwives performed shiatsu massages following standard protocols. Pain was assessed using the Numeric Rating Scale, and anxiety was assessed using the Hamilton Anxiety Rating Score at three times including before the intervention (T0), the latent phase (T1), and at transition phase (T2). The impact of the intervention was analyzed using repeated measures analysis of variance by SPSS 26. A p-value less than 0.05 was considered statistically significant.

    RESULTS: The intervention group showed a significant reduction in labour pain scores from 6.85±1.00 (T0) to 6.13±0.88 (T1) and 4.78±0.83 (T2) (P<0.001), while the control group showed an increase from 6.85±1.00 (T0) to 8.05±0.64 (T1) and 8.85±0.48 (T2) (P<0.001). Anxiety scores in the intervention group decreased from 28.53±4.41 (T0) to 26.15±3.59 (T1) and 20.65±2.69 (T2) (P<0.001), whereas the control group experienced an increase from 25.55±3.16 (T0) to 27.05±3.36 (T1) and 31.73±3.27 (T2) (P<0.001). The between-subject effects in time levels for labour pain and anxiety in the two study groups had a significant impact (P<0.001).

    CONCLUSION: Findings showed that shiatsu massage was effective and safe for relieving pain and reducing anxiety during childbirth of nulliparous women. This research suggests that shiatsu massage can be used as an effective alternative method to relieve pain and anxiety during labour in low risk pregnancies, particularly in settings with limited access to pharmaceutical analgesics.Trial Registration Number: IRCT20220317054316N1.

  14. Ibrahim NI, Ahmad MS, Zulfarina MS, Zaris SNASM, Mohamed IN, Mohamed N, et al.
    PMID: 29772744 DOI: 10.3390/ijerph15051002
    Fracture is a type of musculoskeletal injury that contributes to an inability to perform daily activities. The objective of this study was to evaluate activities of daily living (ADL) of older adult patients with lower body fracture and to determine factors influencing ADL. Patient's ADL was assessed at pre-fracture, ward admission and post-discharge phases using the Katz ADL questionnaire. There were 129 subjects at pre-fracture and ward phases and 89 subjects at discharge phase. There were four independent variables; age, gender, type of fracture and ability to walk before fracture. Logistic regression models showed that 'age' and 'ability to walk before fracture' were the determinant factors of dependent for 'bathing', 'dressing' and 'toileting'. The 'ability to walk before fracture' was the determinant factor of dependent for 'transferring'. 'Age' and 'gender' were the determinant factors of dependent for 'continence', while 'age' was the determinant factor of dependent for 'feeding'. The ADL score changes were significant across the phases with a reduction in ADL score in the ward admission phase and partial increment during the post-discharge phase. There were improvements in the health outcomes of subjects aged more than 50 years old after 3 months of being discharged from the hospital. In conclusion, age, being female, having a hip fracture and using a walking aid before fracture were the determinants identified in this study.
  15. Zulfarina MS, Sharif R, Syarifah-Noratiqah SB, Sharkawi AM, Aqilah-Sm ZS, Mokhtar SA, et al.
    PLoS One, 2018;13(8):e0202321.
    PMID: 30106982 DOI: 10.1371/journal.pone.0202321
    Maximizing bone mineral accrual to attain an optimal peak bone mass (PBM), particularly during adolescence, appears to be an effective protective strategy in the prevention of osteoporosis. This study aimed to evaluate the influence of physical activity (PA), fat mass (FM), lean mass (LM), body mass index (BMI), calcium, or combination of vitamin D supplement intake, smoking and alcohol drinking status on bone health assessed by calcaneus quantitative ultrasound (QUS) in a healthy adolescent population. The participants comprised of 920 male and female secondary school adolescents aged 15-17 years old. Quantitative ultrasound measurements of the left heel were performed using Lunar Achilles EX II, which included results of broadband ultrasound attenuation (BUA), speed of sound (SOS), and a calculated stiffness index (SI). Multivariable linear regression analyses revealed that-PA was positively associated with all three QUS indices in both genders; BMI was positively associated with SI and SOS in females; LM was positively associated with BUA in both genders; and FM was negatively associated with SI in females. These variables accounted for 32.1%, 21.2% and 29.4% of females' SOS, BUA and SI variances (p<0.001), respectively and 23.6%, 15.4% and 17.2% of males' SOS, BUA and SI variances (p<0.001), respectively. Promoting health benefits from physical activity could influence bone status and consequently improve PBM, which is a potent protective determinant against osteoporosis in adulthood.
  16. Wyer S, Townsend DM, Ye Z, Kourtidis A, Choo YM, de Barros ALB, et al.
    Biomed Pharmacother, 2022 Feb 08;148:112676.
    PMID: 35149387 DOI: 10.1016/j.biopha.2022.112676
    Since the discovery of the kahalalide family of marine depsipeptides in 1993, considerable work has been done to develop these compounds as new and biologically distinct anti-cancer agents. Clinical trials and laboratory research have yielded a wealth of data that indicates tolerance of kahalalides in healthy cells and selective activity against diseased cells. Currently, two molecules have attracted the greates level of attention, kahalalide F (KF) and isokahalalide F (isoKF, Irvalec, PM 02734, elisidepsin). Both compounds were originally isolated from the sarcoglossan mollusk Elysia rufescens but due to distinct structural characteristics it has been hypothesized and recently shown that the ultimate origin of the molecules is microbial. The search for their true source has been a subject of considerable research in the anticipation of finding new analogs and a culturable expression system that can produce sufficient material through fermentation to be industrially relevant.
  17. Hasan MM, Islam MT, Samsuzzaman M, Baharuddin MH, Soliman MS, Alzamil A, et al.
    Sci Rep, 2022 Jun 08;12(1):9433.
    PMID: 35676407 DOI: 10.1038/s41598-022-13522-5
    This work proposes a compact metasurface (MS)-integrated wideband multiple-input multiple-output (MIMO) antenna for fifth generation (5G) sub-6 GHz wireless communication systems. The perceptible novelty of the proposed MIMO system is its wide operating bandwidth, high gain, lower interelement gap, and excellent isolation within the MIMO components. The radiating patch of the antenna is truncated diagonally with a partially ground plane, and a metasurface has been employed for enhancing the antenna performance. The suggested MS integrated single antenna prototype has a miniature dimension of 0.58λ × 0.58λ × 0.02λ. The simulated and measured findings demonstrate a wideband characteristic starting from 3.11 to 7.67 GHz including a high realized gain of 8 dBi. The four-element MIMO system has been designed by rendering each single antenna orthogonally to one another while retaining compact size and wideband properties between 3.2 and 7.6 GHz. The suggested MIMO prototype has been designed and fabricated on a low loss Rogers RT5880 substrate with a miniature dimension of 1.05λ × 1.05λ × 0.02λ and its performance is evaluated using a suggested 10 × 10 array of a square enclosed circular split ring resonators within the same substrate material. The inclusion of the proposed metasurface with a backplane significantly reduces antenna backward radiation and manipulates the electromagnetic field, thus improving the bandwidth, gain and isolation of MIMO components. The suggested 4-port MIMO antenna offers a high realized gain of 8.3 dBi compared to existing MIMO antennas with an excellent average total efficiency of 82% in the 5G sub-6 GHz spectrum and is in good accordance with measured results. Furthermore, the developed MIMO antenna exhibits outstanding diversity characteristics in respect of envelope correlation coefficient (ECC) less than 0.004, diversity gain (DG) close to 10 dB (> 9.98 dB) and high isolation between MIMO components (> 15.5 dB). Therefore, the proposed MS-inspired MIMO antenna substantiates its applicability for 5G sub-6 GHz communication networks.
  18. Hasan MM, Islam MT, Rahim SKA, Alam T, Rmili H, Alzamil A, et al.
    Materials (Basel), 2023 Feb 20;16(4).
    PMID: 36837381 DOI: 10.3390/ma16041751
    This article demonstrates a compact wideband four-port multiple-input-multiple-output (MIMO) antenna system integrated with a wideband metamaterial (MM) to reach high gain for sub-6 GHz new radio (NR) 5G communication. The four antennas of the proposed MIMO system are orthogonally positioned to the adjacent antennas with a short interelement edge-to-edge distance (0.19λmin at 3.25 GHz), confirming compact size and wideband characteristics 55.2% (3.25-5.6 GHz). Each MIMO system component consists of a fractal slotted unique patch with a transmission feed line and a metal post-encased defected ground structure (DGS). The designed MIMO system is realized on a low-cost FR-4 printed material with a miniature size of 0.65λmin × 0.65λmin × 0.02λmin. A 6 × 6 array of double U-shaped resonator-based unique mu-near-zero (MNZ) wideband metamaterial reflector (MMR) is employed below the MIMO antenna with a 0.14λmin air gap, improving the gain by 2.8 dBi and manipulating the MIMO beam direction by 60°. The designed petite MIMO system with a MM reflector proposes a high peak gain of 7.1 dBi in comparison to recent relevant antennas with high isolation of 35 dB in the n77/n78/n79 bands. In addition, the proposed wideband MMR improves the MIMO diversity and radiation characteristics with an average total efficiency of 68% over the desired bands. The stated MIMO antenna system has an outstanding envelope correlation coefficient (ECC) of <0.045, a greater diversity gain (DG) of near 10 dB (>9.96 dB), a low channel capacity loss (CCL) of <0.35 b/s/Hz and excellent multiplexing efficiency (ME) of higher than -1.4 dB. The proposed MIMO concept is confirmed by fabricating and testing the developed MIMO structure. In contrast to the recent relevant works, the proposed antenna is compact in size, while maintaining high gain and wideband characteristics, with strong MIMO performance. Thus, the proposed concept could be a potential approach to the 5G MIMO antenna system.
  19. Sakib S, Hoque A, Rahim SKBA, Singh M, Sahar NM, Islam MS, et al.
    Materials (Basel), 2023 Jan 30;16(3).
    PMID: 36770180 DOI: 10.3390/ma16031172
    This paper reports a central spiral split-rectangular-shaped metamaterial absorber surrounded by a polarization-insensitive ring resonator for s-band applications. The rated absorption is 99.9% at 3.1 GHz when using a three-layer structure where the top and ground are made of copper and the center dielectric material is a commonly used FR-4 substrate. The central split gaps have an impact on the unit cell by increasing high absorption, and an adequate electric field is apparent in the outer split ring gap. At 3.1 GHz, the permittivity and permeability are negative and positive, respectively, so the proposed unit cell acts as an epsilon negative (ENG) metamaterial absorber. In a further analysis, Roger4450B was used as a substrate and obtained excellent absorption rates of 99.382%, 99.383%, 99.91%, and 95.17% at 1.44, 3.96, 4.205, and 5.025 GHz, respectively, in the S- and C-band regions. This unit cell acts as a single negative metamaterial (SNG) absorber at all resonance frequencies. The S11 and S21 parameters for FR-4 and Rogers4450B were simulated while keeping the polarization angle (θ and φ) at 15, 30, 45, 60, 75, and 90 degrees to measure, permittivity, permeability, reflective index, absorption, and reflection. The values of the reflective index are near zero. Near-zero reflective indexes (NZRI) are widely used in antenna gain propagation. The unit cell fabricated for the FR-4 substrate attained 99.9% absorption. S-band values in the range of (2-4) GHz can be applied for low-frequency radar detection.
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