High-Temperature Atomic Diffusion and Specific Heat in Quasicrystals.

A quasicrystal is an ordered but nonperiodic structure understood as a projection from a higher-dimensional periodic structure. Some physical properties of quasicrystals are different from those of conventional solids. An anomalous increase in heat capacity at high temperatures has been discussed for over two decades as a manifestation of a hidden high dimensionality of quasicrystals. A plausible candidate for this origin has been the phason, which has excitation modes originating from the additional atomic rearrangements introduced by the quasiperiodic order, which can be understood in terms of shifting a higher-dimensional lattice. However, most theoretical studies of phasons have used toy models. A theoretical study of the heat capacity of realistic quasicrystals or their approximants has yet to be conducted because of the huge computational complexity. To bridge this gap between experiment and theory, we show experiments and molecular simulations on the same material, an Al-Pd-Ru quasicrystal, and its approximants. We show that at high temperatures, aluminum atoms diffuse with discontinuouslike jumps, and the diffusion paths of the aluminum can be understood in terms of jumps corresponding to hyperatomic-fluctuations-associated atomic rearrangements of the phason degrees of freedom. It is concluded that the anomaly in the heat capacity of quasicrystals arises from the hyperatomic fluctuations that play a role in diffusive Nambu-Goldstone modes.

Deep Learning Enables Rapid Identification of a New Quasicrystal from Multiphase Powder Diffraction Patterns.

Since the discovery of the quasicrystal, approximately 100 stable quasicrystals are identified. To date, the existence of quasicrystals is verified using transmission electron microscopy; however, this technique requires significantly more elaboration than rapid and automatic powder X-ray diffraction. Therefore, to facilitate the search for novel quasicrystals, developing a rapid technique for phase-identification from powder diffraction patterns is desirable. This paper reports the identification of a new Al-Si-Ru quasicrystal using deep learning technologies from multiphase powder patterns, from which it is difficult to discriminate the presence of quasicrystalline phases even for well-trained human experts. Deep neural networks trained with artificially generated multiphase powder patterns determine the presence of quasicrystals with an accuracy >92% from actual powder patterns. Specifically, 440 powder patterns are screened using the trained classifier, from which the Al-Si-Ru quasicrystal is identified. This study demonstrates an excellent potential of deep learning to identify an unknown phase of a targeted structure from powder patterns even when existing in a multiphase sample.

Crystal structures of five compounds in the aluminium-ruthenium-silicon system.

Single crystals of five compounds with approximate compositions ∼Ru16(Al0.78Si0.22)47, (I), ∼Ru9(Al0.70Si0.30)32, (II), ∼Ru10(Al0.67Si0.33)41, (III), ∼Ru(Al0.57Si0.43)5, (IV), and ∼Ru2(Al0.46Si0.54)9, (V), were obtained from polycrystalline lumps mainly composed of the target compounds, and their crystal structures were determined by means of single-crystal X-ray diffraction. The crystal structure of (I) can be related to that of a cubic rational crystalline approximant to an icosa-hedral quasicrystal through crystallographic shear and then unit-cell twinning. The crystal structure of (II) is isotypic with that of a phase with composition ∼Fe9(Al,Si)32. The crystal structure of (III) is comprised of edge-sharing Ru(Al,Si)9-11 polyhedra with disordered chains along edges of polyhedra. The crystal structure of (IV) is of the LiIrSn4 type. The crystal structure of (V) can be viewed as a crystallographic shear structure derived from that of (IV).

Psychological and physiological effect in humans of touching plant foliage - using the semantic differential method and cerebral activity as indicators.

BACKGROUND: Numerous studies have reported on the healing powers of plants and nature, but there have not been so many instances of experimental research. In particular, there are very few psychological and physiological studies using tactile stimuli. This study examines the psychological and physiological effects of touching plant foliage by using an evaluation profile of the subjects' impressions and investigating cerebral blood flow. METHODS: The subjects were 14 young Japanese men aged from 21 to 27 years (mean ± standard deviation: 23.6 ± 2.4). With their eyes closed, the subjects touched four different tactile samples including a leaf of natural pothos (Epipremnum aureum). The physiological indices were compared before and after each stimulus. Psychological indices were obtained using a 'semantic differential' method. RESULTS: The fabric stimulus gave people 'soft' and 'rough' impressions, 'kind', 'peaceful' and 'pleasant' feelings psychologically, and a sense of physiological calm. On the other hand, the metal stimulus gave people 'cold', 'smooth' and 'hard' impressions and an image of something 'artificial'. The metal stimulus caused a stress response in human cerebral blood flow although its evaluation in terms of 'pleasant or unpleasant' was neutral. There were no remarkable differences between the stimuli of natural and artificial pothos compared with other types of stimulus psychologically. However, only the natural pothos stimulus showed a sense of physiological calm in the same appearance as the fabric stimulus. CONCLUSIONS: This study shows that people experience an unconscious calming reaction to touching a plant. It is to be concluded that plants are an indispensable element of the human environment.

[Evaluation of the chemokine variation in tears of contact lens wearers].

PURPOSE: To evaluate the variation of chemokines in tears of contact lens wearers. SUBJECTS AND METHODS: The subjects were divided into the three groups: a control group consisting of 26 eyes of 26 healthy volunteers without contact lenses a contact lens group (CL group) consisting of 30 eyes of 30 healthy contact lens wearers without ocular surface disorders, and a giant papillary conjunctivitis group (GPC group) consisting of 9 eyes of 9 patients with giant papillary conjunctivitis caused by contact lens wearing. Tear samples were taken by the modified Schirmer I method using a filter paper. Tear samples were eluted and analyzed for chemokines including interleukin-8 (IL-8), eotaxin-2, and pulmonary and activation-regulated CC chemokine (PARC) by the antibody array method. Concentrations of IL-8, eotaxin-2, and PARC in tears were determined quantitatively by enzyme-linked immunosorbent assay (ELISA). RESULTS: Using the antibody array method, the expression of IL-8, eotaxin-2, and PARC in the GPC group was 4-fold higher or greater than in the control group. In the measurement by ELISA, IL-8 levels in the GPC group (1154.5 +/- 1739.3 pg/ml) (mean +/- SD) were significantly higher (Kruskal-Wallis test, p < 0.01) than in the control (75.2 +/- 88.7 pg/ml) and CL (153.6 +/- 252.8 pg/ml) groups. The eotaxin-2 levels in tears did not show a statistical difference among the three groups. The PARC level in tears of the GPC group (2859.6 +/- 2299.9 pg/ml) was significantly higher than in the control(589.0 +/- 324.8 pg/ml) and CL (671.7 +/- 536.2 pg/ml) groups (Kruskal-Wallis test, p < 0.05). CONCLUSION: Wearing a contact lens per se disorders, does not cause chemokine variation in tears. However, an increase of IL-8 which induces neutrophilic invasion and an increase of PARC which induces lymphocyte invasion play an important roles in increasing the risk factor of GPC when wearing contacts.

Pars plana suture fixation for intraocular lenses dislocated into the vitreous cavity using a closed-eye cow-hitch technique.

We describe a modified intraocular cow-hitch technique for pars plana suture fixation of intraocular lenses (IOLs) that dislocated into the vitreous cavity in 3 patients who had a 3-port vitrectomy and IOL implantation because of retinal disease. To reposition the dislocated IOL after the residual vitreous was removed, 2 additional sclerotomies for suture fixation were made 3.0 mm posterior to the limbus. A loop (cow-hitch knot) was made with 10-0 polypropylene for suture fixation. After the neck of the cow-hitch loop was grasped with an intraocular forceps, the loop was used to lasso a haptic of the dislocated IOL, which was then pulled forward to the sclerotomy. The same procedure was used for the other haptic, and both sutures were secured to the sclera under scleral flaps. In all patients, the dislocated IOLs were repositioned without the need for extraction. The procedures were uneventful. Pars plana suture fixation with the intraocular cow-hitch technique can be used to reposition an IOL that has dislocated into the vitreous cavity.

Histological study of conjunctiva-associated lymphoid tissue in mouse.

PURPOSE: To investigate conjunctiva-associated lymphoid tissue (CALT) in the mouse conjunctiva by histological methods. METHODS: The presumed follicular tissue in the conjunctiva of normal mice, age ranging from 4 to 6 weeks, was histologically investigated by the hematoxylin-eosin staining method. Next, we treated the mice with topical instillation of a combined solution of ovalbumin and cholera toxin B to investigate the morphological changes of conjunctival follicles to antigen challenge. The treated mice underwent sequential clinical examinations, and the conjunctival follicular tissue was examined by an immunohistochemical method using anti-CD4 antibody, anti-CD8 antibody, and anti-S-100 antibody. RESULTS: Follicular tissue was present on the mouse nictitating membrane. Both size and number of follicular tissue areas increased with topical ovalbumin treatment. Immunohistochemical study revealed CD4, CD8, and S-100 positive cells in the follicular tissue. The epithelial layer, corresponding to follicular tissue, demonstrated intra-epithelial pocket and the presence of CD4-positive cells in the intra-epithelial pocket. CONCLUSION: Follicular tissue at the nictitating membrane is CALT in the mouse.

[Clinical study on surgical outcome of penetrating keratoplasty for herpetic leukoma].

PURPOSE: To evaluate prognostic factors, rejection, and recurrence of herpetic keratitis, in keratoplasty for herpetic leukoma. SUBJECTS AND METHODS: We compared surgical outcome between patients who underwent keratoplasty for herpetic leukoma and those who received it for non-herpetic disorders. We compared the eyes of 24 patients in the herpetic group with 17 eyes of 20 patients with non-herpetic corneal disorders, i.e., the non-herpetic group. RESULTS: The rejection rate was 45.8% for the herpetic group and 5.00% for the non-herpetic group, showing significant difference(p < 0.05). Transparent grafts were obtained for 75.0% of the herpetic group and 85.0% of the non-herpetic group, giving no significant difference. In the herpetic group, graft transparency in eyes with recurrences were 94.1%(p < 0.05). Graft rejection occurred mostly within 1 year postoperatively. RecuRrent herpetic keratitis tended to occur within 3 years and it was later than graft rejection. CONCLUSION: In patients who underwent keratoplasty for herpetic leukoma, steroid therapy is important for 1 postoperative year to suppress graft rejection, but after that, steroid treatment should be carefully considered to minimize the risk of recurrences of herpetic keratitis.

[Histological study of conjunctiva-associated lymphoid tissue in mice].

PURPOSE: To investigate conjunctiva-associated lymphoid tissue (CALT) in mouse conjunctiva. METHOD: We examined normal mice, ranging in age from 4 to 6 weeks, to investigate the presence of follicular tissue histologically. Next, we treated mice by topical instillation of ovalbumin and cholera toxin B, and then examined conjunctival follicles by immunohistological methods. RESULTS: Follicular tissue was present at the nictitating membrane. Both size and amount of follicular tissue was increased by the topical ovalbumin treatment. Immunohistological examination revealed CD4, CD8, and S-100 protein positive cells in follicular tissue. The epithelial layer, corresponding to follicular tissue, had intraepithelial pockets and CD4 positive cells in the pockets. CONCLUSION: It was concluded that the follicular tissue at the nictitating membrane is CALT in mice.