341 research outputs found
Vitreous preservation of articular cartilage from cryoinjury in rabbits
Frozen osteoarticular grafts treated with liquid nitrogen are utilized for joint reconstruction after tumor resection, but the joints may subsequently develop osteoarthritic changes. To preserve articular cartilage from cryoinjury, we modified a vitrification method utilized for embryo cryopreservation and demonstrated in vitro that our vitrification protocol was effective for protecting cartilage from cryoinjury. In this study, we investigated in vivo whether this vitrification method could protect against osteoarthritic changes in articular cartilage. Osteochondral plugs were obtained from the distal femur of rabbits. These grafts were divided into 3 groups: Fresh group (F-group), non-vitrification group (N-group), and vitrification group (V-group). After treatment, the plugs were re-implanted as autografts. Histological findings, chondrocyte viability, and ultrastructural examinations were examined 6, 12, and 24. weeks after implantation. Histological findings of chondrocytes for the V-group showed no significant difference from those of the F-group at any time point except at 24. weeks postimplantation at the non-weight bearing site (p<0.05). Viability of chondrocyte showed no significant difference from those of the F-group except at 12. weeks postimplantation at the bearing site (p<0.05). In contrast, viable cells disappeared from the N-group and histology and viability significantly differed between the N-group and the V-group. Transmission electron microscopy demonstrated preservation of chondrocyte structure in the V-group and the F-group, but chondrocytes of the N-group were abnormally electron dense. Our vitrification method was effective in protecting chondrocytes from cryoinjury that might lead to cartilage degeneration. Reconstructing joints with osteoarticular grafts containing living cartilage may help to avert osteoarthritic changes. Our vitrification method could prove useful for reconstruction with frozen tumor-containing autografts and for long-term storage of living cartilage for allografts. © 2012 Elsevier Inc
Mechanistic Insight on the Formation of GaN:ZnO Solid Solution from Zn–Ga Layered Double Hydroxide Using Urea as the Nitriding Agent
A solid solution of GaN and ZnO (GaN:ZnO) is promising as a photocatalyst for visible light-driven overall water splitting to produce H2. However, several obstacles still exist in the conventional preparation procedure of GaN:ZnO. For example, the atomic distributions of Zn and Ga are non-uniform in GaN:ZnO when a mixture of the metal oxides, i.e., Ga2O3 and ZnO, is used as a precursor. In addition, GaN:ZnO is generally prepared under harmful NH3 flow for long durations at high temperatures. Here, a facile synthesis of GaN:ZnO with homogeneous atomic composition via a simple and safe procedure is reported. A layered double hydroxide (LDH) containing Zn2+ and Ga3+ was used to increase the uniformity of the atomic distributions of Zn and Ga in GaN:ZnO. We employed urea as a nitriding agent instead of gaseous NH3 to increase the safety of the reaction. Through the optimization of reaction conditions such as heattreatment temperature and content of urea, single-phase GaN:ZnO was successfully obtained. In addition, the nitridation mechanism using urea was investigated in detail. NH3 released from the thermal decomposition of urea did not directly nitride the LDH precursor. X-ray absorption and infrared spectroscopies revealed that Zn(CN2)-like intermediate species were generated at the middle temperature range and Ga–N bonds formed at high temperature along with dissociation of CO and CO2.This file includes Supporting Information.This work was supported by JSPS KAKENHI Grant Number JP16H06438, JP16H06441, JP17H05483, JP17H03392. This work was partly supported by the Center for Functional Nano Oxide at Hiroshima University. The synchrotron radiation experiments were performed at the BL01B1 beamline of SPring-8 with the approval of the Japan Synchrotron Radiation Research 32 Institute (JASRI) (Proposal No. 2017B1043 and 2018A1749)
Practicality Verification of an Application Virtualization System Assuming Use of BYOD Environment
From 2019, We - Kyushu Institute of Technology started to bring and use students’ laptops (called “BYOD on education”) in some lectures. In the same timing, we have replaced our information systems for education and research use (we call “Education systems”). The new system is turned to support our BYOD environment on education scene. For one thing that, “Application virtualization system” has been adopted. It behaves as “the application was installed on PCs” without some installation procedures. It can be expected to enhance lectures such as some exercise using software. Before providing application virtualization system, some practicality verification is needed. We adopt this system to 30 different software for education and research use. After verification, we judged that 25 of 30 software can be adopting for BYOD environment on education scene
Topologically Linked Crystals
We discovered a new class of topological crystals, namely linked rings of
crystals. Two rings of tantalum triselenide (TaSe3) single crystals were linked
to each other while crystal growing. The topology of the crystal form is called
a "Hopf link", which is the simplest link involving just two component unknots
linked together exactly once. The feature of the crystals is not covered by the
conventional crystallography.Comment: 6 pages, 3 figures, to appear in J. Crystal Growt
Population-level transition of capsular polysaccharide types among sequence type 1 group B Streptococcus isolates with reduced penicillin susceptibility during a long-term hospital epidemic
Over a 35-month period, group B Streptococcus isolates with reduced penicillin susceptibility (PRGBS) were detected from elderly patients at a regional hospital in Japan, accompanying population-level transition of PRGBS serotypes. The genetic relatedness of 77 non-duplicate PRGBS from 73 patients was analysed. Serotype III PRGBS predominated (16 serotype III/1 serotype Ib) in the first 9 months (period I), then 3 serotype Ib isolates appeared transiently for the next 3 months (period II), which was replaced predominantly by serotype Ia (20 serotype Ia/1 serotype III/1 non-typeable) for 9 months (period III). In the last 14 months (period IV), besides 25 serotype Ia isolates, 10 serotype III were also identified. Serotypes III and Ia isolates, belonging to ST1, shared G329V, G398A, V405A and G429D substitutions in penicillin-binding protein 2X. Of three strains subjected to whole-genome sequencing, serotype III strain SU12 (period I) had a higher degree of genomic similarity with serotype Ia strain SU97 (period III) than serotype Ib strain SU67 (period II) based on average nucleotide identity and single nucleotide polymorphisms. Analysis of the cps gene clusters and the upstream and downstream flanking sequences revealed that disruption of the hyaluronidase gene located upstream of cpsY by insertion of IS 1548 was found in strain SU12, whereas Delta ISSag8 was inserted between tRNA-Arg and rpsA genes located downstream of cpsL in strain SU97. Interestingly, most serotype III PRGBS re-emerging in period IV had this tRNA-Arg-Delta ISSag8-rpsA region. Capsular switching and nosocomial transmission may possibly contribute to population-level serotype replacement among ST1 PRGBS isolates. (c) 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.ArticleINTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS.53(3):203-210(2019)journal articl
Retrorectal epidermoid cyst with unusually elevated serum SCC level, initially diagnosed as an ovarian tumor
Retrorectal epidermoid cyst is one of the developmental cysts which arise from remnants of embryonic tissues. We report a rare case of retrorectal epidermoid cyst, initially diagnosed as an ovarian tumor. Serum SCC value as tumor marker was elevated to the high level. Laparoscopy revealed ovaries, uterus and other pelvic organs were all normal. This tumor existed in the retroperitoneal cavity and compressed the rectum. Later, complete tumor resection was performed by laparotomy. Histological study revealed the epithelium of this tumor consisted of only squamous cells without atypia, and the diagnosis of this tumor was retrorectal epidermoid cyst. Retrorectal epidermoid cyst is very rare, and difficult to diagnose before surgery. However, if we have-knowledge of developmental cysts, and by careful digital examination and image diagnosis, a differential diagnosis can be made
Central administration of melanocortin agonist increased insulin sensitivity in diet-induced obese rats
AbstractIn this study, we examined the effects of intracerebroventricular administration of melanotan II (MTII), a melanocortin agonist, on insulin sensitivity in diet-induced obese (DIO) rats. Although MTII treatment significantly decreased food intake and body weight for 10 days, there was no significant difference in body weight between MTII and pair-fed groups. The insulin tolerance test showed that insulin sensitivity was significantly improved in the MTII group compared to the pair-fed group. Furthermore, MTII treatment increased the number of small-sized adipocytes in epididymal white adipose tissues, suggesting that MTII increased insulin sensitivity through action on the white adipose tissues in DIO rats
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