Displaying publications 81 - 100 of 4601 in total

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  1. A concise review of testosterone and bone health
    Mohamad NV, Soelaiman IN, Chin KY
    Clin Interv Aging, 2016;11:1317-1324.
    PMID: 27703340
    Osteoporosis is a condition causing significant morbidity and mortality in the elderly population worldwide. Age-related testosterone deficiency is the most important factor of bone loss in elderly men. Androgen can influence bone health by binding to androgen receptors directly or to estrogen receptors (ERs) indirectly via aromatization to estrogen. This review summarized the direct and indirect effects of androgens on bone derived from in vitro, in vivo, and human studies. Cellular studies showed that androgen stimulated the proliferation of preosteoblasts and differentiation of osteoblasts. The converted estrogen suppressed osteoclast formation and resorption activity by blocking the receptor activator of nuclear factor k-B ligand pathway. In animal studies, activation of androgen and ERα, but not ERβ, was shown to be important in acquisition and maintenance of bone mass. Human epidemiological studies demonstrated a significant relationship between estrogen and testosterone in bone mineral density and fracture risk, but the relative significance between the two remained debatable. Human experimental studies showed that estrogen was needed in suppressing bone resorption, but both androgen and estrogen were indispensable for bone formation. As a conclusion, maintaining optimal level of androgen is essential in preventing osteoporosis and its complications in elderly men.
    Matched MeSH terms: Androgens/physiology*; Bone and Bones/physiology*; Estrogens/physiology*; Osteoclasts/physiology; Receptors, Androgen/physiology; Testosterone/physiology*; Estrogen Receptor alpha/physiology
  2. Insight into potential mechanisms of hypobaric hypoxia-induced learning and memory deficit - Lessons from rat studies
    Qaid E, Zakaria R, Sulaiman SF, Yusof NM, Shafin N, Othman Z, et al.
    Hum Exp Toxicol, 2017 Dec;36(12):1315-1325.
    PMID: 28111974 DOI: 10.1177/0960327116689714
    Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.
    Matched MeSH terms: Learning/physiology*
  3. Miracidial maze. Use of a free-choice system to test Echinostome miracidia in their relative attraction towards normal and abnormal snails hosts, living, dead, whole, and dissected snails
    Heyneman D
    Med J Malaya, 1966 Jun;20(4):354-5.
    PMID: 4224364
    Matched MeSH terms: Trematoda/physiology*
  4. Order error in the calculation of continuous relative phase
    Mehdizadeh S, Glazier PS
    J Biomech, 2018 05 17;73:243-248.
    PMID: 29628131 DOI: 10.1016/j.jbiomech.2018.03.032
    The aims of this study were to demonstrate "order error" in the calculation of continuous relative phase (CRP) and to suggest two alternative methods-(i) constructing phase-plane portraits by plotting position over velocity; and (ii), the Hilbert transform-to rectify it. Order error is the change of CRP order between two degrees of freedom (e.g., body segments) when using the conventional method of constructing phase-plane portraits (i.e., velocity over position). Both sinusoidal and non-sinusoidal simulated signals as well as signals from human movement kinematics were used to investigate order error and the performance of the two alternative methods. Both methods have been shown to lead to correct results for simulated sinusoidal and non-sinusoidal signals. For human movement data, however, the Hilbert transform is superior for calculating CRP.
    Matched MeSH terms: Walking/physiology*
  5. Fulltext Nutrients and Oxidative Stress: Friend or Foe?
    Tan BL, Norhaizan ME, Liew WP
    Oxid Med Cell Longev, 2018;2018:9719584.
    PMID: 29643982 DOI: 10.1155/2018/9719584
    There are different types of nutritionally mediated oxidative stress sources that trigger inflammation. Much information indicates that high intakes of macronutrients can promote oxidative stress and subsequently contribute to inflammation via nuclear factor-kappa B- (NF-κB-) mediated cell signaling pathways. Dietary carbohydrates, animal-based proteins, and fats are important to highlight here because they may contribute to the long-term consequences of nutritionally mediated inflammation. Oxidative stress is a central player of metabolic ailments associated with high-carbohydrate and animal-based protein diets and excessive fat consumption. Obesity has become an epidemic and represents the major risk factor for several chronic diseases, including diabetes, cardiovascular disease (CVD), and cancer. However, the molecular mechanisms of nutritionally mediated oxidative stress are complex and poorly understood. Therefore, this review aimed to explore how dietary choices exacerbate or dampen the oxidative stress and inflammation. We also discussed the implications of oxidative stress in the adipocyte and glucose metabolism and obesity-associated noncommunicable diseases (NCDs). Taken together, a better understanding of the role of oxidative stress in obesity and the development of obesity-related NCDs would provide a useful approach. This is because oxidative stress can be mediated by both extrinsic and intrinsic factors, hence providing a plausible means for the prevention of metabolic disorders.
    Matched MeSH terms: Oxidative Stress/physiology*
  6. Synechococcus production and grazing loss rates in nearshore tropical waters
    Heng PL, Lim JH, Lee CW
    Environ Monit Assess, 2017 Mar;189(3):117.
    PMID: 28220442 DOI: 10.1007/s10661-017-5838-1
    Temporal variation of Synechococcus, its production (μ) and grazing loss (g) rates were studied for 2 years at nearshore stations, i.e. Port Dickson and Port Klang along the Straits of Malacca. Synechococcus abundance at Port Dickson (0.3-2.3 × 10(5) cell ml(-1)) was always higher than at Port Klang (0.3-7.1 × 10(4) cell ml(-1)) (p  0.25), but nutrient and light availability were important factors for their distribution. The relationship was modelled as log Synechococcus = 0.37Secchi - 0.01DIN + 4.52 where light availability (as Secchi disc depth) was a more important determinant. From a two-factorial experiment, nutrients were not significant for Synechococcus growth as in situ nutrient concentrations exceeded the threshold for saturated growth. However, light availability was important and elevated Synechococcus growth rates especially at Port Dickson (F = 5.94, p  0.30). In nearshore tropical waters, an estimated 69 % of Synechococcus production could be grazed.
    Matched MeSH terms: Synechococcus/physiology*
  7. Molecular biology of Macrobrachium rosenbergii nodavirus infection in giant freshwater prawn
    Low CF, Md Yusoff MR, Kuppusamy G, Ahmad Nadzri NF
    J Fish Dis, 2018 Dec;41(12):1771-1781.
    PMID: 30270534 DOI: 10.1111/jfd.12895
    Macrobrachium rosenbergii nodavirus (MrNV) has been threatening the giant freshwater prawn aquaculture since 1997, causing white tail disease in the prawn species that leads to 100% lethality of the infected postlarvae. Comprehension of the viral infectivity and pathogenesis at molecular biology level has recently resolved the viral capsid protein and evidenced the significant difference in the viral structural protein compared to other nodaviruses that infect fish and insect. Cumulative researches have remarked the proposal to assert MrNV as a member of new genus, gammanodavirus to the Nodaviridae family. The significance of molecular biology in MrNV infection is being highlighted in this current review, revolving the viral life cycle from virus binding and entry into host, virus replication in host cell, to virus assembly and release. The current review also highlights the emerging aptamers technology that is also known as synthetic antibody, its application in disease diagnosis, and its prophylactic and therapeutic properties. The future perspective of synthetic virology technology in understanding viral pathogenesis, as well as its potential in viral vaccine development, is also discussed.
    Matched MeSH terms: Nodaviridae/physiology*
  8. Fulltext Fabrication of a Multiplexed Artificial Cellular MicroEnvironment Array
    Mashimo Y, Yoshioka M, Tokunaga Y, Fockenberg C, Terada S, Koyama Y, et al.
    J Vis Exp, 2018 09 07.
    PMID: 30247461 DOI: 10.3791/57377
    Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are well orchestrated and are crucial in regulating cell functions in a living system. Although a number of researchers have attempted to investigate the correlation between environmental factors and desired cellular functions, much remains unknown. This is largely due to the lack of a proper methodology to mimic such environmental cues in vitro, and simultaneously test different environmental cues on cells. Here, we report an integrated platform of microfluidic channels and a nanofiber array, followed by high-content single-cell analysis, to examine stem cell phenotypes altered by distinct environmental factors. To demonstrate the application of this platform, this study focuses on the phenotypes of self-renewing human pluripotent stem cells (hPSCs). Here, we present the preparation procedures for a nanofiber array and the microfluidic structure in the fabrication of a Multiplexed Artificial Cellular MicroEnvironment (MACME) array. Moreover, overall steps of the single-cell profiling, cell staining with multiple fluorescent markers, multiple fluorescence imaging, and statistical analyses, are described.
    Matched MeSH terms: Cellular Microenvironment/physiology*
  9. Fulltext Physiological State and Learning Ability of Students in Normal and Virtual Reality Conditions: Complexity-Based Analysis
    Babini MH, Kulish VV, Namazi H
    J Med Internet Res, 2020 06 01;22(6):e17945.
    PMID: 32478661 DOI: 10.2196/17945
    BACKGROUND: Education and learning are the most important goals of all universities. For this purpose, lecturers use various tools to grab the attention of students and improve their learning ability. Virtual reality refers to the subjective sensory experience of being immersed in a computer-mediated world, and has recently been implemented in learning environments.

    OBJECTIVE: The aim of this study was to analyze the effect of a virtual reality condition on students' learning ability and physiological state.

    METHODS: Students were shown 6 sets of videos (3 videos in a two-dimensional condition and 3 videos in a three-dimensional condition), and their learning ability was analyzed based on a subsequent questionnaire. In addition, we analyzed the reaction of the brain and facial muscles of the students during both the two-dimensional and three-dimensional viewing conditions and used fractal theory to investigate their attention to the videos.

    RESULTS: The learning ability of students was increased in the three-dimensional condition compared to that in the two-dimensional condition. In addition, analysis of physiological signals showed that students paid more attention to the three-dimensional videos.

    CONCLUSIONS: A virtual reality condition has a greater effect on enhancing the learning ability of students. The analytical approach of this study can be further extended to evaluate other physiological signals of subjects in a virtual reality condition.

    Matched MeSH terms: Learning/physiology*
  10. Fulltext Kinematics of mouthbrooding in Oreochromis niloticus (Cichlidae)
    Van Wassenbergh S, Joris I, Desclée M, Liew HJ, De Boeck G, Adriaens D, et al.
    J Exp Biol, 2016 05 15;219(Pt 10):1535-41.
    PMID: 27207955 DOI: 10.1242/jeb.131631
    Many species from several different families of fishes perform mouthbrooding, where one of the sexes protects and ventilates the eggs inside the mouth cavity. This ventilation behaviour differs from gill ventilation outside the brooding period, as the normal, small-amplitude suction-pump respiration cycles are alternated with actions including near-simultaneous closed-mouth protrusions and high-amplitude depressions of the hyoid. The latter is called churning, referring to its hypothetical function in moving around and repositioning the eggs by a presumed hydrodynamic effect of the marked shifts in volume along the mouth cavity. We tested the hypothesis that churning causes the eggs located posteriorly in the mouth cavity to move anteriorly away from the gill entrance. This would prevent or clear accumulations of brood at the branchial basket, which would otherwise hinder breathing by the parent. Dual-view videos of female Nile tilapias (Oreochromis niloticus) during mouthbrooding showed that churning involves a posterior-to-anterior wave of expansion and compression of the head volume. Flow visualisation with polyethylene microspheres revealed a significant inflow of water entering the gill slits at the zone above the pectoral fin base, followed by a predominantly ventral outflow passing the ventrolaterally flapping branchiostegal membranes. X-ray videos indicated that particularly the brood located close to the gills is moved anteriorly during churning. These data suggest that, in addition to mixing of the brood to aid its oxygenation, an important function of the anterior flow through the gills and buccal cavity during churning is to prevent clogging of the eggs near the gills.
    Matched MeSH terms: Behavior, Animal/physiology*; Gills/physiology; Mouth/physiology*; Ovum/physiology; Posture/physiology; Water/physiology; Cichlids/physiology*
  11. Improvement on upper limb body-powered prostheses (1921-2016): A systematic review
    Hashim NA, Abd Razak NA, Abu Osman NA, Gholizadeh H
    Proc Inst Mech Eng H, 2018 Jan;232(1):3-11.
    PMID: 29199518 DOI: 10.1177/0954411917744585
    Body-powered prostheses are known for their advantages of cost, reliability, training period, maintenance, and proprioceptive feedback. This study primarily aims to analyze the work related to the improvement of upper limb body-powered prostheses prior to 2016. A systematic review conducted via the search of the Web of Science electronic database, Google Scholar, and Google Patents identified 155 papers from 1921 to 2016. Sackett's initial rules of evidence were used to determine the levels of evidence, and only papers categorized in the design and development category and patents were analyzed. A total of 40 papers in the sixth level of "Design and Development" of an upper limb body-powered prosthesis were found. Approximately 81% were categorized under mechanical alteration. Most papers were patent-type documents (48%), with the Journal of Rehabilitation Research and Development publishing most of the articles related to the design and development of body-powered prostheses. Papers in the scope of the study were published once every 3 years in almost a century, proving that only a few studies were conducted to improve body-powered arms compared with myoelectric technology. Further research should be carried out mainly in areas that have received less attention.
    Matched MeSH terms: Upper Extremity/physiology*
  12. Fulltext An Indo-Pacific coral spawning database
    Baird AH, Guest JR, Edwards AJ, Bauman AG, Bouwmeester J, Mera H, et al.
    Sci Data, 2021 01 29;8(1):35.
    PMID: 33514754 DOI: 10.1038/s41597-020-00793-8
    The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology.
    Matched MeSH terms: Anthozoa/physiology*
  13. Fulltext Epstein Barr Virus Reactivation during COVID-19 Hospitalization Significantly Increased Mortality/Death in SARS-CoV-2(+)/EBV(+) than SARS-CoV-2(+)/EBV(-) Patients: A Comparative Meta-Analysis
    Manoharan S, Ying LY
    Int J Clin Pract, 2023;2023:1068000.
    PMID: 36793928 DOI: 10.1155/2023/1068000
    Epstein-Barr virus (EBV) reactivation in acute-phase of COVID-19 disease was recently discovered but it is not clear in terms of degree of mortality caused, and this was the aim of the current study. Six databases and three non-databases were thoroughly searched, independently. The articles related to non-human study (abstract, in vitro, in vivo, in silico, case study, poster, and review articles) were excluded for main analysis. Four articles related to mortality linked to EBV reactivation were systematically identified and included in the qualitative and quantitative analyses. Based on proportional meta-analysis of 4 studies, 34.3% or 0.343 (95% CI: 0.189-0.516; I 2 = 74.6) mortality related to EBV reactivation was identified. To address high heterogeneity, subgroup meta-analysis was carried out. Based on subgroup analysis, 26.6% or 0.266 (95% CI: 0.191-0.348; I 2 = 0) with no heterogeneity was identified. Interestingly, in comparative meta-analysis, EBV(-)/SARS-CoV-2(+) patients had statistically lesser mortality (9.9%) than EBV(+)/SARS-CoV-2(+) patients (23.6%) where RR = 2.31 (95% CI: 1.34-3.99; p = 0.003; I 2 = 6%). This finding is equivalent to the absolute mortality effect of 130 more per 1000 COVID-19 patients (95% CI: 34-296). Furthermore, based on statistical analysis, D-dimer was not statistically significantly different (p > 0.05) between the groups although studies have shown that D-dimer was statistically significantly different (p < 0.05) between these groups. Based on the inclusion and analysis of low risk of bias and high quality of articles graded with Newcastle-Ottawa Scale (NOS), when COVID-19 patients' health state is gradually worsening, EBV reactivation needs to be suspected because EBV reactivation is a possible marker for COVID-19 disease severity.
    Matched MeSH terms: Herpesvirus 4, Human/physiology
  14. Solutions to fire and shade: resprouting, growing tall and the origin of Eurasian temperate broadleaved forest
    Adie H, Lawes MJ
    Biol Rev Camb Philos Soc, 2023 Apr;98(2):643-661.
    PMID: 36444419 DOI: 10.1111/brv.12923
    Tree species of Eurasian broadleaved forest possess two divergent trait syndromes with contrasting patterns of resource allocation adapted to different selection environments: short-stature basal resprouters that divert resources to a bud bank adapted to frequent and severe disturbances such as fire and herbivory, and tall trees that delay reproduction by investing in rapid height growth to escape shading. Drawing on theory developed in savanna ecosystems, we propose a conceptual framework showing that the possession of contrasting trait syndromes is essential for the persistence of broadleaved trees in an open ecosystem that burns. Consistent with this hypothesis, trees of modern Eurasian broadleaved forest bear a suite of traits that are adaptive to surface and crown-fire regimes. We contend that limited opportunities in grassland restricts recruitment to disturbance-free refugia, and en masse establishment creates a wooded environment where shade limits the growth of light-demanding savanna plants. Rapid height growth, which involves investment in structural support and the switch from a multi-stemmed to a monopodial growth form, is adaptive in this shaded environment. Although clustering reduces surface fuel loads, these establishment nuclei are vulnerable to high-intensity crown fires. The lethal effects of canopy fire are avoided by seasonal leaf shedding, and aerial resprouting enhances rapid post-fire recovery of photosynthetic capacity. While these woody formations satisfy the structural definition of forest, their constituents are clearly derived from savanna. Contrasting trait syndromes thus represent the shift from consumer to resource regulation in savanna ecosystems. Consistent with global trends, the diversification of most contemporary broadleaved taxa coincided with the spread of grasslands, a surge in fire activity and a decline in wooded ecosystems in the late Miocene-Pliocene. Recognition that Eurasian broadleaved forest has savanna origins and persists as an alternative state with adjacent grassy ecosystems has far-reaching management implications in accordance with functional rather than structural criteria. Shade is a severe constraint to the regeneration and growth of both woody and herbaceous growth forms in consumer-regulated ecosystems. However, these ecosystems are highly resilient to disturbance, an essential process that maintains diversity especially among the species-rich herbaceous component that is vulnerable to shading when consumer behaviour is altered.
    Matched MeSH terms: Trees/physiology
  15. Fulltext Curcumin effect on Acanthamoeba triangularis encystation under nutrient starvation
    Boonhok R, Sangkanu S, Phumjan S, Jongboonjua R, Sangnopparat N, Kwankaew P, et al.
    PeerJ, 2022;10:e13657.
    PMID: 35811814 DOI: 10.7717/peerj.13657
    BACKGROUND: Curcumin is an active compound derived from turmeric, Curcuma longa, and is known for its benefits to human health. The amoebicidal activity of curcumin against Acanthamoeba triangularis was recently discovered. However, a physiological change of intracellular pathways related to A. triangularis encystation mechanism, including autophagy in the surviving amoeba after curcumin treatment, has never been reported. This study aims to investigate the effect of curcumin on the survival of A. triangularis under nutrient starvation and nutrient-rich condition, as well as to evaluate the A. triangularis encystation and a physiological change of Acanthamoeba autophagy at the mRNA level.

    METHODS: In this study, A. triangularis amoebas were treated with a sublethal dose of curcumin under nutrient starvation and nutrient-rich condition and the surviving amoebas was investigated. Cysts formation and vacuolization were examined by microscopy and transcriptional expression of autophagy-related genes and other encystation-related genes were evaluated by real-time PCR.

    RESULTS: A. triangularis cysts were formed under nutrient starvation. However, in the presence of the autophagy inhibitor, 3-methyladenine (3-MA), the percentage of cysts was significantly reduced. Interestingly, in the presence of curcumin, most of the parasites remained in the trophozoite stage in both the starvation and nutrient-rich condition. In vacuolization analysis, the percentage of amoebas with enlarged vacuole was increased upon starvation. However, the percentage was significantly declined in the presence of curcumin and 3-MA. Molecular analysis of A. triangularis autophagy-related (ATG) genes showed that the mRNA expression of the ATG genes, ATG3, ATG8b, ATG12, ATG16, under the starvation with curcumin was at a basal level along the treatment. The results were similar to those of the curcumin-treated amoebas under a nutrient-rich condition, except AcATG16 which increased later. On the other hand, mRNA expression of encystation-related genes, cellulose synthase and serine proteinase, remained unchanged during the first 18 h, but significantly increased at 24 h post treatment.

    CONCLUSION: Curcumin inhibits cyst formation in surviving trophozoites, which may result from its effect on mRNA expression of key Acanthamoeba ATG-related genes. However, further investigation into the mechanism of curcumin in A. triangularis trophozoites arrest and its association with autophagy or other encystation-related pathways is needed to support the future use of curcumin.

    Matched MeSH terms: Trophozoites/physiology
  16. Does resistance training in older adults lead to structural brain changes associated with a lower risk of Alzheimer's dementia? A narrative review
    Nicola L, Loo SJQ, Lyon G, Turknett J, Wood TR
    Ageing Res Rev, 2024 Jul;98:102356.
    PMID: 38823487 DOI: 10.1016/j.arr.2024.102356
    Dementia, particularly Alzheimer's Disease (AD), has links to several modifiable risk factors, especially physical inactivity. When considering the relationship between physcial activity and dementia risk, cognitive benefits are generally attributed to aerobic exercise, with resistance exercise (RE) receiving less attention. This review aims to address this gap by evaluating the impact of RE on brain structures and cognitive deficits associated with AD. Drawing insights from randomized controlled trials (RCTs) utilizing structural neuroimaging, the specific influence of RE on AD-affected brain structures and their correlation with cognitive function are discussed. Preliminary findings suggest that RE induces structural brain changes in older adults that could reduce the risk of AD or mitigate AD progression. Importantly, the impacts of RE appear to follow a dose-response effect, reversing pathological structural changes and improving associated cognitive functions if performed at least twice per week for at least six months, with greatest effects in those already experiencing some element of cognitive decline. While more research is eagerly awaited, this review contributes insights into the potential benefits of RE for cognitive health in the context of AD-related changes in brain structure and function.
    Matched MeSH terms: Cognition/physiology
  17. Fulltext Effects of blood flow restriction training on sports performance in athletes: a systematic review with meta-analysis
    Li R, Chee CS, Kamalden TF, Ramli AS, Yang K
    J Sports Med Phys Fitness, 2024 Jan;64(1):55-65.
    PMID: 37902798 DOI: 10.23736/S0022-4707.23.15220-0
    INTRODUCTION: Blood flow restriction training (BFRT) is an effective training method to improve sports performance in healthy athletes. Nevertheless, a systematic review with meta-analysis regarding how BFRT affects sports performance in athletes is still lacking. Consequently, the study attempted to expand and consolidate the prior studies regarding the effect of BFRT on technical and physical performance in athletes.

    EVIDENCE ACQUISITION: This study was based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes) statement guidelines for a systematic review of the academic databases Scopus, Web of Science, PubMed, EBSCOhost (SportDiscus), and Google Scholar. The PEDro scale was used to assess the methodological quality of the included publications, which ranged from moderate to high quality. The systematic review protocol was registered on inplasy.com (INPLASY202380049).

    EVIDENCE SYNTHESIS: Out of 249 studies identified, 93 articles were evaluated as eligible, and after the screening, 18 studies were finally included in this systematic review. Meta-analysis results showed a significant enhancement on vertical jump height in the BFRT group compared to the control group (SMD=1.39, 95% CI=0.30-2.49, P=0.01). BFRT was able to significantly increase maximal oxygen uptake (SMD=1.65, 95% CI=0.56-2.74, P<0.01). While no significant improvement in sprint time was observed (SMD= -0.18, 95% CI=-1.18-0.82, P=0.115).

    CONCLUSIONS: The finding suggests that BFRT is beneficial to athletes as this training method can be effective in enhancing physical and technical performance in athletes. Nevertheless, further analysis needs to be conducted to fully determine the effectiveness of the moderators of the intervention on sports performance.

    Matched MeSH terms: Muscle Strength/physiology
  18. Leaf thermotolerance of Hevea brasiliensis clones: intra- versus interclonal variation and relationships with other functional traits
    Hazir MHM, Gloor E, Docherty E, Galbraith D
    Tree Physiol, 2024 Feb 11;44(3).
    PMID: 38349811 DOI: 10.1093/treephys/tpae022
    Land surface temperature is predicted to increase by 0.2 °C per decade due to climate change, although with considerable regional variability, and heatwaves are predicted to increase markedly in the future. These changes will affect where crops can be grown in the future. Understanding the thermal limits of plant physiological functioning and how flexible such limits are is thus important. Here, we report on the measurements of a core foliar thermotolerance trait, T50, defined as the temperature at which the maximum quantum yield (Fv/Fm) of photosystem II declines by 50%, across nine different Malaysian Hevea brasiliensis clones. We explore the relative importance of interclonal versus intraclonal variation in T50 as well as its association with leaf and hydraulic traits. We find very low variation in T50 within individual clones (mean intraclonal coefficient of variation (CoV) of 1.26%) and little variation across clones (interclonal CoV of 2.1%). The interclonal variation in T50 was lower than for all other functional traits considered. The T50 was negatively related to leaf mass per area and leaf dry matter content, but it was not related to hydraulic traits such as embolism resistance (P50) or hydraulic safety margins (HSM50). The range of T50 observed (42.9-46.2 °C) is well above the current maximum air temperatures Tmax,obs (T50 - Tmax,obs >5.8 °C), suggesting that H. brasiliensis is likely thermally safe in this south-east Asian region of Malaysia.
    Matched MeSH terms: Plant Leaves/physiology
  19. Recent progress on anti-nociceptive effects of carbon monoxide releasing molecule-2 (CORM-2)
    Khir NAM, Noh ASM, Long I, Zakaria R, Ismail CAN
    Mol Cell Biochem, 2024 Mar;479(3):539-552.
    PMID: 37106243 DOI: 10.1007/s11010-023-04749-5
    The role of carbon monoxide (CO) has evolved albeit controversial disputes on its toxicity. This biological gasotransmitter participates in the endogenous regulation of neurotransmitters and neuropeptides released in the nervous system. Exogenous CO gas inhalation at a lower concentration has been the subject of investigations, which have revealed its biological homeostatic mechanisms and protective effects against many pathological conditions. This therapeutic procedure of CO is, however, limited due to its immediate release, which favours haemoglobin at a high affinity with the subsequent generation of toxic carboxyhaemoglobin in tissues. In order to address this problem, carbon monoxide releasing molecule-2 (CORM-2) or also known as tricarbonyldichlororuthenium II dimer is developed to liberate a controlled amount of CO in the biological systems. In this review, we examine several potential mechanisms exerted by this therapeutic compound to produce the anti-nociceptive effect that has been demonstrated in previous studies. This review could shed light on the role of CORM-2 to reduce pain, especially in cases of chronic and neuropathic pain.
    Matched MeSH terms: Carbon Monoxide/physiology
  20. Subterranean termite open-air foraging and tolerance to desiccation: Comparative water relation of two sympatric Macrotermes spp. (Blattodea: Termitidae)
    Hu J, Neoh KB, Appel AG, Lee CY
    Comp Biochem Physiol A Mol Integr Physiol, 2012 Feb;161(2):201-7.
    PMID: 22085890 DOI: 10.1016/j.cbpa.2011.10.028
    The foraging patterns of termites are strongly related to physiological limits in overcoming desiccation stress. In this study, we examined moisture preferences and physiological characteristics of Macrotermes carbonarius (Hagen) and M. gilvus (Hagen) as both exhibit conspicuous patterns of foraging activity. Despite both species showing no significant differences in calculated cuticular permeability, and percentage of total body water, they differed greatly in rate of water loss and surface area to volume ratio. For example, M. carbonarius which had a lower surface area to volume ratio (29.26-53.66) showed lower rate of water loss and percentage of total body water loss. This also resulted in higher LT(50) when exposed to extreme conditions (≈2% RH). However, contrasting observations were made in M. gilvus that has smaller size with higher surface area to volume ratio of 40.28-69.75. It is likely that the standard equation for calculating insect surface areas is inadequate for these termite species. The trend was further supported by the result of a moisture preference bioassay that indicated M. carbonarius had a broader range of moisture preference (between 5% and 20%) than M. gilvus which had a relatively narrow moisture preference (only 20%). These results explain why M. carbonarius can tolerate desiccation stress for a longer period foraging above-ground in the open air; while M. gilvus only forages below ground or concealed within foraging mud tubes.
    Matched MeSH terms: Body Water/physiology; Body Weight/physiology; Feeding Behavior/physiology*; Water/physiology*; Isoptera/physiology*; Integumentary System/physiology; Sympatry/physiology*
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