Conversion of N-acetyl-d-glucosamine to nitrogen-containing chemicals in high-temperature water

Available online 19 July 2019To demonstrate the conversion of renewable biomass to platform chemicals, we previously reported the non catalytic conversion of N-acetyl-D-glucosamine (GlcNAc), which is obtained from chitin, to nitrogen-containing chemicals; however, various aspects of this process were not clarified. Herein, we reported updated and expanded results for the synthesis of nitrogen-containing chemicals from GlcNAc in high-temperature water at 180-280 degrees C and 25 MPa with a reaction time of 5-34 s. The main products were 2-acetamido-2,3-dideoxy-D-erythro-hex-2-enofuranose (Chromogen I) and 3-acetamido-5-(1',2'-dihydroxyethyl)furan (Chromogen III) with the maximum yields of 37.0% and 34.5%, respectively. Although 3-acetamido-5-acetylfuran was expected to form by the dehydration of Chromogen III, a yield of only < 1% was obtained, likely because the dehydration of Chromogen III is difficult in the absence of a catalyst. The evaluation of the effects of acid and base catalysts on the dehydration of GlcNAc revealed that the acid catalyst suppressed the transformation of GlcNAc to Chromogen I and promoted the transformation of Chromogen I to Chromogen III, whereas the base catalyst had the opposite effects on these processes. The synthesis of nitrogen-containing chemicals from GlcNAc in high temperature water is an environmentally benign method for utilizing renewable chitin biomass.ArticleFUEL PROCESSING TECHNOLOGY. 195:106154 (2019)journal articl

Non-catalytic conversion of chitin into Chromogen I in high-temperature water

Epub 2019 June 21The non-catalytic conversion of chitin into N-acetyl-ᴅ-glucosamine (GlcNAc) derivatives such as 2-acetamido-2,3-dideoxy-ᴅ-erythro-hex-2-enofuranose (Chromogen I) was investigated in high-temperature water at 290–390 °C and 25 MPa with a reaction time of 0–180 min. High-temperature water treatment is a promising method for chitin conversion as it does not require the use of any additional organic solvents or ionic liquids. A semi-batch reactor was developed to control the reaction temperature and time. It was found that the chitin powder could be converted into a water-soluble fraction in ~90% yield, with Chromogen I being obtained in a maximum yield of 2.6%. Furthermore, a kinetic model was developed to estimate the reaction rate for the conversion of the chitin powder to the water-soluble fraction.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 136:994-999 (2019)journal articl

Direct Patterning of Ceramic Circuit Board with Q-Switched Nd:YAG Laser

Direct patterning of copper coated ceramic circuit board is experimentally investigated with Q-switched Nd:YAG laser in order to shorten the time of the trial manufacture of electronic circuit board and to adapt the flexible design change. It is pointed out that the fast direct patterning the speed of which reaches about 100 mm/s is possible if the repetition frequency and the average power are selected properly. Furthermore cutting off and/or drilling of ceramic board are also possible under the condition that the repetition frequency is less than 3kHz. This technique makes it possible the mask1ess patterning of ceramic circuit board which has been widely used recently in place of conventional glass-epoxy or phenolic resin circuit board, and it leads to the shorter time limit of delivery as compared with the conventional end-milling method

One autopsy case of an elderly traffic accident victim with Tetralogy of Fallot

The case of a61-year-old male traffic accident victem with Tetralogy of Fallot (TOF) is reported. The autopsy revealed massive hemorrhages in the subcutaneous tissue, muscle, and subarachnoidal space. Furthermore, multiple fractures of ribs, sternum and thoracic vertebrae were observed. Histopathological examination revealed changes characteristic of trauma, such as acute lung congestion, acute renal cortical necrosis, and embolization in the lungs and kidney. These autopsy and histological observations indi-cated that traumatic shock was cause of his death. Moreover, histologically, we observed changes due to his congenital heart disease, such as right ventricular hypertrophy, heart failure cells in the lungs, sclerosis of the liver, and hyaline degeneration in the kidney. Furthermore, ischemic changes, shrinkage or loss of neurons, were seen in hippocampus, and swelling of astrocytes in both cortex and hippocampus were also observed. These observations lead us to speculate that a hypoxic episode may have caused his accidental death while driving

ヒト網膜色素上皮はヒドロキノンと最終糖化産物の共刺激により、VEGF遺伝子の発現上昇を伴って増殖する

Although recent research showed that advanced glycation endproduct (AGE) and hydroquinone (HQ) are related to the pathogenesis of age-related macular degeneration (AMD), the mechanism how AGE and HQ induce or accelerate AMD remains elusive. In the present study, we examined the effects of AGE and HQ on changes of human retinal pigment epithelial (RPE) cell numbers and found that the viable cell numbers were markedly reduced by HQ by apoptosis and that AGE prevented the decreases of HQ-treated cell numbers by increased replicative DNA synthesis of RPE cells without changing apoptosis. Real-time RT-PCR revealed that vascular endothelial growth factor (VEGF)-A mRNA was increased by HQ treatment and the addition of HQ+AGE resulted in a further increment. The increase of VEGF secretion was confirmed by ELISA, and inhibition of VEGF signaling by chemical inhibitors and small interfering RNA decreased the HQ+AGE-induced increases in RPE cell numbers. The deletion analysis demonstrated that −102 to −43 region was essential for the VEGF-A promoter activation. Site-directed mutaions of specificity protein 1 (SP1) binding sequences in the VEGF-A promoter and RNA interference of SP1 revealed that SP1 is an essential transcription factor for VEGF-A expression. These results indicate that HQ induces RPE cell apoptosis, leading to dry AMD, and suggest that AGE stimulation in addition to HQ enhances VEGF-A transcription via the AGE-receptor for AGE pathway in HQ-damaged cells. As a result, the secreted VEGF acts as an autocrine/paracrine growth factor for RPE and/or adjacent vascular cells, causing wet AMD.博士（医学）・甲第640号・平成27年11月27日Copyright © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Use of Recombinant Endolysin to Improve Accuracy of Group B Streptococcus Tests

Group B Streptococcus (GBS) causes serious neonatal infection via vertical transmission. The prenatal GBS screening test is performed at the late stage of pregnancy to avoid risks of infection. In this test, enrichment culture is performed, followed by GBS identification. Selective medium is used for the enrichment; however, Enterococcus faecalis, which is a potential contaminant in swab samples, can interfere with the growth of GBS. Such bacterial contamination can lead to false-negative results. Endolysin, a bacteriophage-derived enzyme, degrades peptidoglycan in the bacterial cell wall; it is a promising antimicrobial agent for selectively eliminating specific bacterial genera/species. In this study, we used the recombinant endolysin EG-LYS, which is specific to E. faecalis; the endolysin potentially enriched GBS in the selective culture. First, in the false-negative model (coculture of GBS and E. faecalis, which disabled GBS detection in the subsequent GBS identification test), EG-LYS treatment at 0.1 mg/ml improved GBS detection. Next, we used 548 vaginal swabs to test the efficacy of EG-LYS treatment in improving GBS detection. EG-LYS treatment (0.1 mg/ml) increased the GBS-positive ratio to 17.9%, compared to 15.7% in the control (phosphate-buffered saline [PBS] treatment). In addition, there were an increased number of GBS colonies under EG-LYS treatment in some samples. The results were supported by the microbiota analysis of the enriched cultures. In conclusion, EG-LYS treatment of the enrichment culture potentially improves the accuracy of the prenatal GBS screening test

Scribing of Ceramie Circuit Board with Q-Switched Nd：YAG Laser

Scribing of copper coated alumina ceramic board with Q-switched YAG laser used for the maskless direct patterning of circuit　board is experimentally investigated, which leads to efficient production of trial circuit board. Better dividing of alumina circuit board 655μm in thickness can be attained by the scribing of about 100μm depth. Higher repetition frequency of laser irradiation leads to smaller notch angle and lower breaking load