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Following ovulation, oocytes undergo a time-dependent deterioration in quality referred to as post-ovulatory ageing. Although various factors influence the post-ovulatory ageing of oocytes, oxidative stress is a key factor involved in deterioration of oocyte quality. Artemisia asiatica Nakai ex Pamp. has been widely used in East Asia as a food ingredient and traditional medicine for the treatment of inflammation, cancer, and microbial infections. Recent studies have shown that A. asiatica exhibits antioxidative effects. In this study, we investigated whether A. asiatica has the potential to attenuate deterioration in oocyte quality during post-ovulatory ageing. Freshly ovulated mouse oocytes were cultured with 0, 50, 100 or 200 μg/ml ethanol extracts of A. asiatica Nakai ex Pamp. After culture for up to 24 h, various ageing-induced oocyte abnormalities, including morphological changes, reactive oxygen species (ROS) accumulation, apoptosis, chromosome and spindle defects, and mitochondrial aggregation were determined. Treatment of oocytes with A. asiatica extracts reduced ageing-induced morphological changes. Moreover, A. asiatica extracts decreased ROS generation and the onset of apoptosis by preventing elevation of the Bax/Bcl-2 expression ratio during post-ovulatory ageing. Furthermore, A. asiatica extracts attenuated the ageing-induced abnormalities including spindle defects, chromosome misalignment and mitochondrial aggregation. Our results demonstrate that A. asiatica can relieve deterioration in oocyte quality and delay the onset of apoptosis during post-ovulatory ageing.
This study examined the effects of a variety of metallurgical factors on the electrochemical corrosion behavior of superaustenitic stainless steel welds. First, the effects of the sigma (σ)-phase on the corrosion behavior were studied by means of a three-dimensional-atom probe. Cr and Mo depletion areas formed around the σ-phases which are precipitated in the interdendritic area were clearly observed. Second, the effects of oxide inclusion on the pitting corrosion of the steel welds were analyzed. The utilization of high resolution transmission electron microscope clearly demonstrated that the thickness and Cr content of the passive film formed on the steel surface decreased significantly with decreasing distance to the oxide inclusion, resulting in a deterioration of the corrosion resistance. Third, the effects of alloying elements, Cu and Al, were evaluated using an electrochemical polarization technique. This confirmed that Cu has a detrimental effect on the resistance to localized corrosion of the steel. The addition of Al up to 0.25 wt% had no significant effects on corrosion resistance in a chloride environment despite the presence of an Al-based oxide layer (Al2O3) on the outermost surface.
There has been controversy over the localized corrosion mechanism of super-austenitic stainless steel weld due mainly to the lack of effective evaluation technique for identification of corrosion nucleation site in weld. For this reason, an electrochemical polarization method followed by an observation of microstructure using the back-scattered electron mode in field emission-scanning electron microscopy is used. To clarify the localized corrosion mechanism, energy dispersive spectroscopy line profile analyzed by transmission electron microscopy is additionally utilized. It clearly reveals that the selective corrosion is preferentially initiated around the σ-phase precipitated in the interdendritic region in weld. The local depletion of Cr and Mo around the σ-phase can be partly replenished by the diffusion of the elements into the depleted area during the subsequent heat treatment at 1180 °C.
In 2000, Korea Astronomy Observatory launched the Near-Earth Object Patrol (NEOPAT) program. NEOPAT has conducted follow-up observations of NEOCP (NEO Confirmation Page) objects and discovered 52 new main-belt asteroids during the observation runs. We initiated collaboration with the Yonsei Survey Telescopes for Astronomical Research (YSTAR) team for NEO search. Wide-field of view, fast read-out time, and fully autonomous data pipeline will enable us to detect and track NEOs with a high efficiency. Scheduled to begin active operations in mid-2001, our survey system is going to be the first network of robotic telescopes for NEO search with automatic access to both hemispheres.
The chemical composition of interstellar grains is derived here on the basis of (1) the cosmic abundance of the elements; (2) the wavelength dependence of extinction and polarization; (3) the average total extinction; (4) the ratio of polarization to extinction; (5) the predominantly dielectric character of grains in the visible spectral region; and (6) infrared spectral characteristics of grains. It is indicated that the major portion of the grains, by mass, consist of core-mantle particles in the 0.1-µm size range, whose cores consist largely of silicates and whose mantles are a solid mixture of O, C, and N with H in a heterogeneous combination of simple and complex molecules with frozen free radicals. A minor constituent of the solid particles exist in the form of very small uncoated particles generally less than 10-6 cm in size whose precise composition is not certain. Inferences of the core-mantle model with respect to spatial distribution are consistent with the proposition that growth of the mantles occurs in the galactic shock region predicted by the density-wave theory. Estimates of the total visual extinction toward the galactic center and the consequent estimates of the total amount of far infrared radiation are shown to depend critically on the grain model. Variations of the ratio of far ultraviolet to visual extinction are correlated with the conditions for growth of mantles on the bare small particles which are generally prevented from accreting mantles primarily because of their extreme temperature fluctuations produced by the ultraviolet photons in the radiation field.
This paper develops a fully modified OLS (FM-OLS) estimator for cointegrating polynomial regressions, i.e., regressions that include as explanatory variables deterministic variables, integrated processes, and integer powers of integrated processes. The stationary errors are allowed to be serially correlated and the regressors are allowed to be endogenous. The paper extends the fully modified estimator of Phillips and Hansen (1990) from cointegrating regressions to cointegrating polynomial regressions. The FM-OLS estimator has a zero-mean Gaussian mixture limiting distribution that allows for standard asymptotic inference. Wald and LM specification tests as well as a KPSS-type test for cointegration are derived. The theoretical analysis is complemented by a simulation study which shows that this FM-OLS estimator, as well as tests based upon it, perform well in the sense that the performance advantages over OLS are largely similar to the performance advantages of FM-OLS over OLS in standard cointegrating regressions.
Several factors associated with referral time to hospice and/or palliative care services have been identified, but there is no literature on the association between these services and the emotional status of the family caregivers (FCs). This article is intended to address that issue.
A semistructured interview was employed to collect data for a retrospective cohort study. The primary FCs of terminally ill cancer patients were interviewed at the time of the patient's referral to the palliative care unit. Interview data were combined with patients' medical record data for our analysis. The emotional status of the FCs was categorized into one of three groups according to their responses to the anticipated death of their family member: acceptance, anxious/depressed, and denial/angry. A Cox proportional hazard model was used to examine and identify the factors related to the length of stay (LOS) in the palliative care unit.
A total of 198 patient–FC pairs were identified. The median LOS was 18 days. A multivariate analysis with adjustment for potential variables revealed significant differences in LOS according to cancer type and time since cancer diagnosis. The denial/angry FC category was independently associated with a shorter LOS (vs. acceptance, adjusted hazard ratio (aHR) 2.11; 95% confidence interval (CI), 1.11–4.03).
Significance of Results:
We found that terminally ill cancer patients who were referred late had FCs who were in denial or were angry about the anticipated death of their loved one. The emotional status of FCs should be considered when patients with terminal cancer are referred to palliative care.
A novel nano-scale manipulator capable of handling low-dimensional materials with three-dimensional linear motion, gripping action, and push–pull action of the gripper was developed for an in situ experiment in transmission electron microscopy. X-Y-Z positioning and push–pull action were accomplished by a piezotubing system, combined with a specially designed assembly stage that consisted of a lever-action gripping tip backed by a push–pull piezostack. The gripper tip consisted of tungsten wire fabricated by electrochemical etching followed by a focused ion beam process. Performance of the nano-scale manipulator was demonstrated in a grab-and-pick test of a single silver nanowire and in an in situ tensile test of a pearlitic steel sample with a specific orientation.
We classify integral modular categories of dimension
are distinct primes. We show that such categories are always group-theoretical, except for categories of dimension
. In these cases there are well-known examples of non-group-theoretical categories, coming from centers of Tambara–Yamagami categories and quantum groups. We show that a non-grouptheoretical integral modular category of dimension
is either equivalent to one of these well-known examples or is of dimension 36 and is twist-equivalent to fusion categories arising froma certain quantum group.
Electrons in topological insulators possess unique electronic band structures and spin properties, promising a novel route to engineer material properties for electronics and energy science. Enhancing the surface state signal in electron transport is critical for both fundamental study of the surface states and future applications. Nanostructures of topological insulators naturally have large surface-to-volume ratios, effectively increasing the surface transport compared to the bulk contribution. Moreover, the unique morphology of topological insulator nanostructures results in various quantum effects of electronic states, which can tailor the surface band via quantum confinement. Here we review recent progress in topological insulator nanostructures. Material design and electron transport of topological insulator nanostructures are introduced, with an emphasis on the unique properties of nanostructures. A few examples of applications and future perspective in using these nanostructures are also discussed.
To investigate whether low vitamin D status was related to insulin resistance (IR) or impaired fasting glucose (IFG) in Korean adolescents, after adjusting for total body fat mass (FM).
A cross-sectional study.
Korea National Health and Nutrition Examination Survey (KNAHNES) 2009–2010.
In total, 1466 participants (769 males) aged 10–19 years were assessed for serum 25-hydroxyvitamin D (25(OH)D) levels, for FM by whole-body dual-energy X-ray absorptiometry and for IR by homeostasis model assessment (HOMA-IR) after an 8 h fast.
Age-, sex-, season- and physical-activity-adjusted regression models showed that serum 25(OH)D levels were significantly related to markers of adiposity (P = 0·016 for FM (g), P = 0·023 for FM (%) and P = 0·035 for fat mass index). When the participants were stratified into three 25(OH)D categories (<37·5 nmol/l (n 553), 37·5 to < 50 nmol/l (n 543) and ≥ 50 nmol/l (n 370)), significantly decreasing trends were observed for fasting insulin (all P < 0·001), HOMA-IR (all P < 0·001) and the odds ratios for IFG (all P for trend < 0·05) from the lowest to the highest 25(OH)D category, after adjustments for age, sex, physical activity and all markers of adiposity. In the multivariate logistic regression analysis, the likelihood of participants in the lowest serum 25(OH)D category having IFG was 2·96–3·15 compared with those in the highest 25(OH)D category (all P < 0·05).
There was a significant inverse relationship between vitamin D status and IR and the risk of IFG, independent of adiposity, in Korean adolescents.
Visual hallucination (VH) is a common psychotic symptom in patients with Parkinson's disease (PD) and may be a significant predictor of cognitive impairment (CI) in such patients.
This study aimed to investigate the pattern of glucose metabolism of VH and the relationship between VH and CI in PD.
We studied 28 PD patients, including 15 with VH (PD-VH) and 13 without VH (PD-NVH). Of the 15 PD-VH patients, 8 patients had cognitive impairment (PD-VHCI) whereas 7 did not (PD-VHNCI). All patients underwent [18F] fluorodeoxyglucose positron emission tomography ([18F] FDG PET) followed by statistical parametric mapping (SPM) analyses.
Compared to the patients with PDNVH, PD-VHNCI patients showed glucose hypometabolism in the inferior and middle temporal cortices, fusiform gyri, and frontal areas, suggesting the involvement of the ventral visual pathway. Compared to the patients with PDNVH, PD-VHCI patients showed glucose hypometabolism in the temporoparietal association cortices with scattered frontal areas.
Dysfunction of ventral visual pathway involving the temporal lobe may play a key role in VH development in PD patients. The evolving distribution from the ventral visual pathway to more extensive posterior cortices in PD-VHCI patients suggests that VH may be a prodromal symptom occurring prior to CI in PD patients.
This chapter reviews functional neuroimaging studies in animals and humans aimed at better understanding the peculiar cerebral mode. It presents evidence that brain activity during rapid eye movement (REM) sleep is influenced by previous experience, suggesting the participation of REM sleep in memory consolidation. Functional neuroimaging research specifically devoted to the characterization of dream correlates has been conducted only during REM sleep. Indeed, mentation during REM sleep is more abundant, vivid, and story-like and hence more detailed dream reports can be obtained from REM than from slow-wave sleep. Motor behavior and movements probably activate motor-related brain areas during REM sleep. A growing body of data indicates that patterns of neural activity prevailing during sleep support offline processing of newly acquired information. The chapter concludes with comments on the difficulty in interpreting functional imaging of REM sleep in terms of neural correlates of dreaming.
Gwendolyn Hyslop, Research Fellow, Linguistics, Australian National University,Stephen Morey, Australian Research Council Future Fellow, Centre for Research on Language Diversity, La Trobe University,Mark W. Post, Oberassistent, Historical Linguistics, Universität Bern
Tiwa, also known as Lalung, is a Tibeto-Burman language of the Bodo-Garo subfamily, and has 27,072 speakers in the Indian state of Assam. Not much is known about the linguistic features of the Tiwa language, and still less is known of its phonology. In this work, we investigate the tones of the Tiwa language with the help of instrumental acoustic measures supported by statistical tests in order to determine the types of tones that exist in the language. We also examine the acoustic characteristics that may help native speakers to distinguish the tones in Tiwa. Furthermore, we investigate how tones operate in non-derived monosyllabic words in the language.
By means of acoustic measures of speech samples collected from nine speakers, plus interviews with native speakers of the language, we come to the conclusion that Tiwa has two lexical tones: a falling tone and a rising tone, and that fundamental frequency (F0) or pitch serves as the major cue in distinguishing among the tones. We also demonstrate that Tiwa is a word-tone language system in which only one tone is assigned to each lexical word of the language, regardless of its syllable quantity.
As with most of the Bodo-Garo languages, not much has been written about Tiwa language. However, the tone systems of the subfamily have received considerable interest; for example, by Baro (1991), Basumatary (2005), Bhattacharya (1977), Burling (1959), Halvorsrud (1959), Joseph and Burling (2001, 2007), Sarmah and Wiltshire (2010a), and Weidert (1987).
The catalytic activity of Pt nanoparticles (NPs) significantly influences the electrochemical performance of direct methanol fuel cells. Information about the factors that influence the electrochemical activity of the catalyst themselves is scarce; hence, guidelines for the preparation of Pt NPs that yields the best performances are lacking. With consideration for this situation, we systematically investigated the relationship(s) between the characteristics of Pt NPs and their electrochemical performance. The general characteristics of Pt NPs, such as the average size, loading density, and dispersion status on the support, were varied in the presence of poly(acrylic acid)-wrapped multiwalled carbon nanotubes by controlling the preparation conditions, including the pH of the aqueous solution, the reaction temperature, and the reaction time. The enhanced catalytic activity is attributable to higher degree of dispersion, specific surface area, and electrochemically active surface area of Pt NPs. The optimized catalyst exhibits a ∼165% higher catalytic activity toward methanol oxidation than the commercial E-TEK.