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Characterizing axonal myelination within the healthy population: a tract-by-tract mapping of effects of age and gender on the fiber g-ratio
No full textAbstractThe g-ratio, equal to the ratio of the inner-to-outer diameter of a myelinated axon, is associated with the speed of conduction, and thus reflects axonal function and integrity. It is now possible to estimate an “aggregate” g-ratio in vivo using MRI. The aim of this study was to assess the variation of the MRI-derived fiber g-ratio in the brain of healthy individuals, and to characterize its variation across the lifespan. Thirty-eight healthy participants, aged between 20 and 76, were recruited. Whole-brain g-ratio maps were computed and analyzed voxel-wise. Median tract g-ratio values were also extracted. No significant effect of gender was found, whereas age was found to be significantly associated with the g-ratio within the white matter. The tract-specific analysis showed this relationship to follow a nearly-linear increase, although the slope appears to slow down slightly after the 6th decade of life. The most likely interpretation is a subtle but consistent reduction in myelin throughout adulthood, with the density of axons beginning to decrease between the 4th and 5th decade
Effects of a supplement combining Pycnogenol® and l-arginine aspartate on lower urinary dysfunction compared with saw palmetto extract
No full textAbstractObjectivesLower urinary tract symptoms (LUTS) and sexual dysfunction (SDys) are common problems that affect quality of life (QOL) in elderly men. In addition to prescribed drugs, many over-the-counter medications including supplements are used to treat QOL diseases. Phosphodiesterase inhibitors are reported to be effective for both LUTS and SDys by increasing nitric oxide levels. French maritime pine bark extract Pycnogenol®, which is a potent nitric oxide donor, is reported to be effective for SDys. However, no reports have been published on whether it ameliorates LUTS.DesignOpen-labeled, randomized study. The effects of two supplements, Nokogiriyashi EX® containing 160 mg saw palmetto (SP) extract per tablet and Edicare® containing 10 mg of Pycnogenol®, 115 mg of l-arginine and 92 mg of aspartate (PAA) per tablet on International Prostate Symptom Score (IPSS), IPSS–QOL, Overactive Bladder Symptom Score (OABSS), International Index of Erectile Function 5 (IIEF5), Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), urinary 8-OHdG and uroflowmetry (UFM) of total 40 men with LUTS and SDys were examined.Results19 subjects were instructed to take two tablets of SP, on the other 20 were on four tablets of PAA for 16 weeks. IPSS and IPSS–QOL showed statistically significant improvements in both groups. OABSS and IIEF5 were significantly improved in the PAA group. Conversely, ICIQ-SF, 8-OHdG and UFM did not change in either group.ConclusionsPAA might be an effective therapeutic alternative for elderly patients with LUTS and SDys
The effect of boron on oxide scale formation in a new polycrystalline superalloy
No full textAbstractBoron addition to a new polycrystalline nickel-based superalloy promotes the formation of a hitherto unreported aluminoborate phase, in the scale produced by oxidation in air at 900°C for ~10,000h. Atom probe tomography provides unambiguous confirmation of this. The ramifications of its formation are discussed
Widespread Antarctic glaciation during the Late Eocene
No full textAbstractMarine sedimentary rocks drilled on the southeastern margin of the South Orkney microcontinent in Antarctica (Ocean Drilling Program Leg 113 Site 696) were deposited between ∼36.5 Ma to 33.6 Ma, across the Eocene–Oligocene climate transition. The recovered rocks contain abundant grains exhibiting mechanical features diagnostic of iceberg-rafted debris. Sand provenance based on a multi-proxy approach that included petrographic analysis of over 275,000 grains, detrital zircon geochronology and apatite thermochronometry rule out local sources (Antarctic Peninsula or the South Orkney Islands) for the material. Instead the ice-transported grains show a clear provenance from the southern Weddell Sea region, extending from the Ellsworth–Whitmore Mountains of West Antarctica to the coastal region of Dronning Maud Land in East Antarctica. This study provides the first evidence for a continuity of widespread glacier calving along the coastline of the southern Weddell Sea embayment at least 2.5 million yrs before the prominent oxygen isotope event at 34–33.5 Ma that is considered to mark the onset of widespread glaciation of the Antarctic continent
A quantitative proteomic screen of the Campylobacter jejuni flagellar-dependent secretome
No full textAbstractCampylobacter jejuni is the leading cause of bacterial gastroenteritis in the world. A number of factors are believed to contribute to the ability of C. jejuni to cause disease within the human host including the secretion of non-flagellar proteins via the flagellar type III secretion system (FT3SS). Here for the first time we have utilised quantitative proteomics using stable isotope labelling by amino acids in cell culture (SILAC), and label-free liquid chromatography-mass spectrometry (LC/MS), to compare supernatant samples from C. jejuni M1 wild type and flagella-deficient (flgG mutant) strains to identify putative novel proteins secreted via the FT3SS. Genes encoding proteins that were candidates for flagellar secretion, derived from the LC/MS and SILAC datasets, were deleted. Infection of human CACO-2 tissue culture cells using these mutants resulted in the identification of novel genes required for interactions with these cells. This work has shown for the first time that both CJM1_0791 and CJM1_0395 are dependent on the flagellum for their presence in supernatants from C. jejuni stains M1 and 81–176.Biological significanceThis study provides the most complete description of the Campylobac er jejuni secretome to date. SILAC and label-free proteomics comparing mutants with or without flagella have resulted in the identification of two C. jejuni proteins that are dependent on flagella for their export from the bacterial cell
Does Chernobyl-derived radiation impact the developmental stability of Asellus aquaticus 30years on?
No full textAbstractEffects of long-term, environmentally relevant doses of radiation on biota remain unclear due to a lack of studies following chronic exposure in contaminated environments. The 1986 Chernobyl accident dispersed vast amounts of radioactivity into the environment which persists to date. Despite three decades of research, impacts of the incident on non-human organisms continues to be contested within the scientific literature. The present study assessed the impact of chronic radiation exposure from Chernobyl on the developmental stability of the model aquatic isopod, Asellus aquaticus using fluctuating asymmetry (FA) as an indicator. Fluctuating asymmetry, defined as random deviations from the expected perfect bilateral symmetry of an organism, has gained prominence as an indicator of developmental stability in ecotoxicology. Organisms were collected from six lakes along a gradient of radionuclide contamination in Belarus and the Ukraine. Calculated total dose rates ranged from 0.06–27.1μGy/h. Fluctuating asymmetry was assessed in four meristic and one metrical trait. Significant differences in levels of pooled asymmetry were recorded between sample sites independent of sex and specific trait measured. However, there was no correlation of asymmetry with radiation doses, suggesting that differences in asymmetry were not attributed to radionuclide contamination and were driven by elevated asymmetry at a single site. No correlation between FA and measured environmental parameters suggested a biotic factor driving observed FA differences. This study appears to be the first to record no evident increase in developmental stability of biota from the Chernobyl region. These findings will aid in understanding the response of organisms to chronic pollutant exposure and the long term effects of large scale nuclear incidents such as Chernobyl and Fukushima
Role of Physiotherapy in Preventing Failure of Primary Anterior Cruciate Ligament Reconstruction 首次前十字韌帶重建手術後物理治療所扮演的角色
No full textAbstractBackground/PurposeAnterior cruciate ligament (ACL) reconstruction is routinely performed in sports medicine. We aimed to determine if there is any protective effect of postoperative physiotherapy in preventing graft rupture after primary ACL reconstruction (ACLR).MethodsA retrospective case–control study was carried out, with demographic data, concomitant meniscal injury, and intraoperative fixation methods matched. The number of sessions of physiotherapy attended by the rupture group and nonrupture group were compared using binary logistic regression.ResultsNo significant relationship between the frequency of postoperative physiotherapy and occurrence of graft rupture after primary ACLR was identified.ConclusionFurther research is needed to verify the effect of physiotherapy in the prevention of graft rupture after primary ACLR
Constraints on lepton number violating short-range interactions from |ΔL|=2 processes
No full textAbstractIn this work we study the short-range contributions that induce effective lepton number violating (LNV) interactions. We obtain a full set of constraints on the effective short-range couplings from a large variety of low-energy |ΔL|=2 processes of pseudoscalar mesons K,D,Ds,B, and τ-lepton. These constraints provide complementary and additional information to the one obtained from the neutrinoless double-β (0νββ) decay. As expected, the bounds on electron–electron short-range couplings are the only ones that are strongly constrained by the 0νββ decay. Although weaker, LNV effective couplings with different flavors are not accessible to 0νββ decay and these can be probe by the |ΔL|=2 processes in consideration
Kinetics, mechanistic and synergistic studies of Alpha lipoic acid with hydrogen peroxide
No full textAbstractAlpha lipoic acid (ALA) holds redox behavior that was observed in the presence of different metals utilizing hydrogen peroxide (H2O2) as a strong oxidizing agent. The effects of different parameters like temperature, pH and concentrations were also monitored.ALA in the presence of hydrogen peroxide (H2O2) showed oxidation as well as degradation processes. To monitor the oxidation kinetics of ALA in the presence of different essential metals to find its reaction pathway using salt affect parameters.The redox behavior of Alpha lipoic acid (ALA) was found to be significant at pH ranging from 4 to 10, at 29°C in a given pseudo first order reaction conditions. The values of the rate constant in the presence of different essential metals such as Mo, Se, Co, Cr, Fe, and Zn were also obtained. Furthermore, synergistic effects were observed in the presence of Mo6+ and Fe2+ at all applied conditions.Activation energy of ALA oxidation is 36.7kJ whereas in the presence of Fe2+ its activation energy went up to 48kJ; however, in the presence of Mo6+ the activation energy drops to 18.3kJ. In the presence of Fe2+ and Mo6+ the synergistic effect works and its activation energy became 36.5kJ. The reaction mechanism was also proposed