241 research outputs found
Fine Structure of the Inner Enamel in Human Permanent Teeth
Using SEM after EDTA etching, the mid-coronal inner enamel of human permanent teeth was classified into three regions of the 1st, 2nd, and 3rd zones. The 1st zone showing a highly negative birefringence was the innermost 10 - 15 μm enamel. This zone consisted of arcade and circular initial prisms, and the succeeding arcade prisms only. These initial prisms arising perpendicularly to the dentine surface resembled pseudoprisms because these prisms showed a somewhat centripetal arrangement of crystal lites and indistinct prism boundaries. The succeeding prisms were frequently bent following a faint slit within the prism. The 2nd zone adjacent to the 1st zone measured 20 - 40 μm in thickness. This zone was mainly composed of horseshoe-shaped prisms with EDTA-insoluble prism sheaths in the deep-etched prism boundaries, but the inner-half layer had dotted irregular prisms including circular, double marginal, and spiral shapes with the prism sheaths. Prismless structures were rarely seen in the 2nd zone. The 3rd zone was mainly occupied by horseshoe-shaped prisms without EDTA-insoluble prism sheaths in the deep-etched prism boundaries, although tuft prisms in the 3rd zone contained a large amount of EDTA-insoluble substances in the prisms, interprismatic regions, and the boundaries
Heterogeneity of Crystals Attached to the Human Enamel and Cementum Surfaces After Calculus Removal In Vitro
Twenty one extracted human teeth with dental calculi on the enamel and cementum surfaces, fixed in 10% neutral formaldehyde, were selected for this study. After ethanol dehydration and air drying, these calculi were removed by tweezers to observe the teeth surfaces under them. The inspection of these surfaces using SEM and EDX revealed hexahedrally based crystals including pseudocuboidal, rhombohedral and variable rugged rocky shapes. These crystals were identified as Mg-containing whitlockite. The pseudocuboidal crystals, measuring about 4.5 μmin maximum length, were widely distributed on the cervical enamel surface previously covered by calculus. On the root surface, however, these areas decreased remakably; the shapes c hanged from pseudocubes into rhombohedrons and rugged rocky structures, while their sizes were smaller and the Mg content decreased. The difference in frequency and morphological variation of the hexahedrally based crystals might be caused by the different characteristics of enamel and cementum surfaces and the Mg present on these surfaces
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Attitudes toward depression among Japanese non-psychiatric medical doctors: A cross-sectional study
Abstract
Background: Under-recognition of depression is common in many countries. Education of medical staff, focusing on their attitudes towards depression, may be necessary to change their behavior and enhance recognition of depression. Several studies have previously reported on attitudes toward depression among general physicians. However, little is known about attitudes of non-psychiatric doctors in Japan. In the present study, we surveyed nonpsychiatric doctors’ attitude toward depression.
Methods: The inclusion criteria of participants in the present study were as follows: 1) Japanese non-psychiatric doctors and 2) attendees in educational opportunities regarding depression care. We conveniently approached two populations: 1) a workshop to depression care for non-psychiatric doctors and 2) a general physician-psychiatrist (GP)network group. We contacted 367 subjects. Attitudes toward depression were measured using the Depression Attitude Questionnaire (DAQ), a 20-item self-report questionnaire developed for general physicians. We report scores of each DAQ item and factors derived from exploratory factor analysis.
Results: We received responses from 230 subjects, and we used DAQ data from 187 non-psychiatric doctors who met the inclusion criteria. All non-psychiatric doctors (n = 187) disagreed with "I feel comfortable in dealing with depressed patients' needs," while 60 % (n = 112) agreed with "Working with depressed patients is heavy going." Factor analysis indicated these items comprised a factor termed "Depression should be treated by psychiatrists" - to which 54 % of doctors (n = 101) agreed. Meanwhile, 67 % of doctors (n = 126) thought that nurses could be useful in depressed patient support. The three factors derived from the Japanese DAQ differed from models previously derived from British GP samples. The attitude of Japanese non-psychiatric doctors concerning whether depression should be treated by psychiatrists was markedly different to that of British GPs.
Conclusions: Japanese non-psychiatric doctors believe that depression care is beyond the scope of their duties. It is suggested that educational programs or guidelines for depression care developed in other countries such as the UK are not directly adaptable for Japanese non-psychiatric doctors. Developing a focused educational program that motivates non-psychiatric doctors to play a role in depression care is necessary to enhance recognition and treatment of depression in Japan
Yanagita Kunio and the culture film: discovering everydayness and creating/imagining a national community, 1935–1945
In wartime Japan, folklore studies (minzokugaku) as an academic discipline emerged at the same time as the rise of the culture film (bunka eiga). Both helped mobilize peripheral areas and firmly created the image of a unitary nation. This paper focuses on Living by the Earth (Tsuchi ni ikiru, 1941), directed by Miki Shigeru, and its spinoff photo album titled People of the Snow Country (Yukiguni no minzoku, 1944). Miki filmed rural life and ordinary people in the Tohoku region under the strong influence of Yanagita Kunio, a founder of Japanese folklore studies, and published the photo album in collaboration with Yanagita. In this project, vanishing customs were paradoxically regarded as objects impossible to photograph. However, that paradox enhanced the value of the project and made it easier to construct an imagined national community through the discourse of folklore studies
Status of GRB Observations with the Suzaku Wideband All-sky Monitor
The Wide-band All-sky Monitor (WAM) is a function of the large lateral BGO
shield of the Hard X-ray Detector (HXD) onboard Suzaku. Its large geometrical
area of 800 cm^2 per side, the large stopping power for the hard X-rays and the
wide-field of view make the WAM an ideal detector for gamma-ray bursts (GRBs)
observations in the energy range of 50-5000 keV. In fact, the WAM has observed
288 GRBs confirmed by other satellites, till the end of May 2007.Comment: 4 pages, 4 figures, to be published in the proceedings of ''Gamma Ray
Bursts 2007'', Santa Fe, New Mexico, November 5-
Honesty mediates the relationship between serotonin and reaction to unfairness
How does one deal with unfair behaviors? This subject has long been investigated by various disciplines including philosophy, psychology, economics, and biology. However, our reactions to unfairness differ from one individual to another. Experimental economics studies using the ultimatum game (UG), in which players must decide whether to accept or reject fair or unfair offers, have also shown that there are substantial individual differences in reaction to unfairness. However, little is known about psychological as well as neurobiological mechanisms of this observation. We combined a molecular imaging technique, an economics game, and a personality inventory to elucidate the neurobiological mechanism of heterogeneous reactions to unfairness. Contrary to the common belief that aggressive personalities (impulsivity or hostility) are related to the high rejection rate of unfair offers in UG, we found that individuals with apparently peaceful personalities (straightforwardness and trust) rejected more often and were engaged in personally costly forms of retaliation. Furthermore, individuals with a low level of serotonin transporters in the dorsal raphe nucleus (DRN) are honest and trustful, and thus cannot tolerate unfairness, being candid in expressing their frustrations. In other words, higher central serotonin transmission might allow us to behave adroitly and opportunistically, being good at playing games while pursuing self-interest. We provide unique neurobiological evidence to account for individual differences of reaction to unfairness
One-dimensional metal-organic framework photonic crystals used as platforms for vapor sorption.
We present the fabrication of one-dimensional photonic crystals (Bragg stacks) based on a microporous metal–organic framework material and mesoporous titanium dioxide. The Bragg stack heterostructures were obtained using two complementary synthesis approaches utilizing the bottom-up assembly of heterogeneous, i.e. two-component photonic crystal multilayer structures. Zeolitic imidazolate framework ZIF-8 and mesoporous titanium dioxide were chosen as functional components with different refractive indices. While ZIF-8 is intended to impart molecular selectivity, mesoporous TiO2 is used to ensure high refractive index contrast and to guarantee molecular diffusion within the Bragg stack. The combination of micro- and mesoporosity within one scaffold endows the 1D-MOF PC with characteristic adsorption properties upon exposure to various organic vapors. In this context, the sorption behavior of the photonic material was studied as a function of partial pressure of organic vapors. The results show that the multilayered photonic heterostructures are sensitive and selective towards a series of chemically similar solvent vapors. It is thus anticipated that the concept of multilayer heterogeneous photonic structures will provide a versatile platform for future selective, label-free optical sensors
Suzaku X-Ray Imaging and Spectroscopy of Cassiopeia A
Suzaku X-ray observations of a young supernova remnant, Cassiopeia A, were
carried out. K-shell transition lines from highly ionized ions of various
elements were detected, including Chromium (Cr-Kalpha at 5.61 keV). The X-ray
continuum spectra were modeled in the 3.4--40 keV band, summed over the entire
remnant, and were fitted with a simplest combination of the thermal
bremsstrahlung and the non-thermal cut-off power-law models. The spectral fits
with this assumption indicate that the continuum emission is likely to be
dominated by the non-thermal emission with a cut-off energy at > 1 keV. The
thermal-to-nonthermal fraction of the continuum flux in the 4-10 keV band is
best estimated as ~0.1. Non-thermal-dominated continuum images in the 4--14 keV
band were made. The peak of the non-thermal X-rays appears at the western part.
The peak position of the TeV gamma-rays measured with HEGRA and MAGIC is also
shifted at the western part with the 1-sigma confidence. Since the location of
the X-ray continuum emission was known to be presumably identified with the
reverse shock region, the possible keV-TeV correlations give a hint that the
accelerated multi-TeV hadrons in Cassiopeia A are dominated by heavy elements
in the reverse shock region.Comment: Publ. Astron. Soc. Japan 61, pp.1217-1228 (2009
Observations of the Prompt Gamma-Ray Emission of GRB 070125
The long, bright gamma-ray burst GRB 070125 was localized by the
Interplanetary Network. We present light curves of the prompt gamma-ray
emission as observed by Konus-WIND, RHESSI, Suzaku-WAM, and \textit{Swift}-BAT.
We detail the results of joint spectral fits with Konus and RHESSI data. The
burst shows moderate hard-to-soft evolution in its multi-peaked emission over a
period of about one minute. The total burst fluence as observed by Konus is
erg/cm (20 keV--10 MeV). Using the spectroscopic
redshift , we find that the burst is consistent with the ``Amati''
correlation. Assuming a jet opening angle derived from
broadband modeling of the burst afterglow, GRB 070125 is a significant outlier
to the ``Ghirlanda'' correlation. Its
collimation-corrected energy release ergs is
the largest yet observed.Comment: 25 pages, 6 figures; accepted for publication in ApJ. Improved
spectral fits and energetics estimate
Attitudes towards suicide in urban and rural China: a population based, cross-sectional study
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