Experimental Study on Carbonation Resistance and Water Absorbing Property of Concrete Crack with repair

Existing RC Buildings have some cracks and the repairing service might last the buildings for long life. The durability of the RC component is evaluated by several ways as like as carbonation resistance test, permeability test, water penetration test, and so on. Therefore, it need to be measured how much advantage the concrete crack with repair have for the durability. The aim of this paper is to study on advantage of repairing a crack of concrete to the carbonation resistance and the waterabsorbing property by the experimental way. The specimens were prepared in the following point. The finishing (direct finishing and mortal tile finishing), crack width (0, 0.05, 0.5, and 2mm), and choice repairing or not. All concrete specimens were formed 10 x 10 x 20cm and those W/C were 0.55. Then, the specimens were tested by the accelerated carbonation. After 4, 8 and 26weeks accelerated carbonation, the carbonation depth and the carbonation shape of the concretes were measured by 1% phenolphthalein reaction. Also, the amount of absorbed water from the bottom were measured at 1, 3, 6, 24, 48, 72 and 168h. From the results, the carbonation went rapidly located in 2cm around the crack in the case of the no-repair specimens, regardless of any finishing. But in the case of the specimens repaired, it went evenly from the exposure side. And water absorbing test results show a trend that water amount of the concrete with a crack more increase than one of the no-crack concrete

Octacalcium phosphate crystals including a higher density dislocation improve its materials osteogenecity

Herein, we show that the enhanced osteogenecity of octacalcium phosphate (OCP) biomaterial, recently identified as an important element in hybrid organic–inorganic nanocomposites involved in the initial hydroxyapatite crystal expansion in mammal bones, results from an enhanced chemical property, stemming from the presence of lattice strain and dislocations. Two types of OCPs were synthesized by wet-chemical processing in the presence (c-OCP) and absence (w-OCP) of gelatin, respectively, and subjected to structural, chemical, and biological analyses. High-resolution transmission electron microscopy (HRTEM) and fast Fourier transform (FFT) analyses revealed that c-OCP crystals contained approximately six times higher edge dislocations with Burgers vectors perpendicular to a-axis than that in the case of w-OCP. The dissolution of c-OCP crystal in tris-HCl buffer occurred toward the long axis of the crystal, most likely, toward the lattice strain along the c-axis direction, while w-OCP crystal dissolved toward the a-axis direction. The study suggested that the increment of internal energy by the higher dislocation density contributed promoting c-OCP dissolution and hydrolysis through decreasing the activation energy. c-OCP crystal displayed enhanced in vitro mesenchymal stem 2D cell and 3D spheroid differentiation, in vivo bone formation, and apatite crystallographic orientation in critical-sized rat calvarial defect model as compared to w-OCP crystal, at the same time, converting to apatite structure earlier than w-OCP. The present study demonstrates that dislocation-related dissolution along with enhanced conversion of OCP is a determinant in bone induction, which may be relevant to normal bone development utilizing OCP biomaterials.Hamai R., Sakai S., Shiwaku Y., et al. Octacalcium phosphate crystals including a higher density dislocation improve its materials osteogenecity. Applied Materials Today, 26, 101279. https://doi.org/10.1016/j.apmt.2021.101279

Antibacterial iodine-supported titanium implants

金沢大学医薬保健研究域医学系Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I 2) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I2 as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I2 vs. stainless steel and titanium controls. Ti-I2 clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I2 pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I2 and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I2 has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I2 substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Prevention of pin tract infection with titanium-copper alloys

金沢大学医薬保健研究域医学系The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial. © 2009 Wiley Periodicals, Inc

Direction-sensitive dark matter search results in a surface laboratory

We developed a three-dimensional gaseous tracking device and performed a direction-sensitive dark matter search in a surface laboratory. By using 150 Torr carbon-tetrafluoride (CF_4 gas), we obtained a sky map drawn with the recoil directions of the carbon and fluorine nuclei, and set the first limit on the spin-dependent WIMP (Weakly Interacting Massive Particles)-proton cross section by a direction-sensitive method. Thus, we showed that a WIMP-search experiment with a gaseous tracking device can actually set limits. Furthermore, we demonstrated that this method will potentially play a certain role in revealing the nature of dark matter when a low-background large-volume detector is developed.Comment: 9 figures, accepted for publication in Phys. Lett.

Investigation of the serum levels of anterior pituitary hormones in male children with autism

<p>Abstract</p> <p>Background</p> <p>The neurobiological basis of autism remains poorly understood. The diagnosis of autism is based solely on behavioural characteristics because there are currently no reliable biological markers. To test whether the anterior pituitary hormones and cortisol could be useful as biological markers for autism, we assessed the basal serum levels of these hormones in subjects with autism and normal controls.</p> <p>Findings</p> <p>Using a suspension array system, we determined the serum levels of six anterior pituitary hormones, including adrenocorticotropic hormone and growth hormone, in 32 drug-naive subjects (aged 6 to 18 years, all boys) with autism, and 34 healthy controls matched for age and gender. We also determined cortisol levels in these subjects by enzyme-linked immunosorbent assay. Serum levels of adrenocorticotropic hormone, growth hormone and cortisol were significantly higher in subjects with autism than in controls. In addition, there was a significantly positive correlation between cortisol and adrenocorticotropic hormone levels in autism.</p> <p>Conclusion</p> <p>Our results suggest that increased basal serum levels of adrenocorticotropic hormone accompanied by increased cortisol and growth hormone may be useful biological markers for autism.</p

Alteration of Plasma Glutamate and Glutamine Levels in Children with High-Functioning Autism

浜松医科大学学位論文　医博第624号（平成24年3月19日

Plasma Cytokine Profiles in Subjects with High-Functioning Autism Spectrum Disorders

Accumulating evidence suggests that dysregulation of the immune system is involved in the pathophysiology of autism spectrum disorders (ASD). The aim of the study was to explore immunological markers in peripheral plasma samples from non-medicated subjects with high-functioning ASD.A multiplex assay for cytokines and chemokines was applied to plasma samples from male subjects with high-functioning ASD (n = 28) and matched controls (n = 28). Among a total of 48 analytes examined, the plasma concentrations of IL-1β, IL-1RA, IL-5, IL-8, IL-12(p70), IL-13, IL-17 and GRO-α were significantly higher in subjects with ASD compared with the corresponding values of matched controls after correction for multiple comparisons.The results suggest that abnormal immune responses as assessed by multiplex analysis of cytokines may serve as one of the biological trait markers for ASD

Performance of a Time-Projection-Chamber with a Large-Area Micro-Pixel-Chamber Readout

A micro time-projection-chamber (micro-TPC) with a detection volume of 23*28*31 cm^3 was developed, and its fundamental performance was examined. The micro-TPC consists of a micro pixel chamber with a detection area of 31*31 cm^2 as a two-dimensional imaging device and a gas electron multiplier with an effective area of 23*28 cm^2 as a pre-gas-multiplier. The micro-TPC was operated at a gas gain of 50,000, and energy resolutions and spatial resolutions were measured.Comment: 4 pages, 7 figures, proceedings of IWORID