155 research outputs found
Optimization of polyol production via liquefaction from Acacia mangium and analysis of the polyols by traditional methods and two dimensional correlation spectroscopy
The aim was to optimize the liquefaction conditions of Acacia mangium wood flour with polyethylene glycol (PEG#400) as the solvent in the presence of sulfuric acid as a catalyst under atmospheric pressure. Reaction time (30–180 min), temperature (130–170°C), and the solvent ratio (PEG/glycerol=0–25%) were varied to obtain the lowest residue content. The resulting polyol was characterized by their hydroxyl number (OHN), acid number (AN), viscosity, molecular weight (Mw), thermogravimetric analysis, Fourier transform infrared (FT-IR) and two-dimensional correlation spectroscopy (2D-COS). The OHN was lowered, AN and Mw were elevated as a function of increasing the reaction temperature and the time. Introducing glycerol in the PEG system markedly increased the OHN, AN and viscosity of the liquefied wood. The optimum condition was 80/20% ratio of PEG/glycerol at 150°C in 150 min leading to a 75% liquefaction yield. The 1730 cm−1 band was indicative for the esters in the liquefied product. The 2D-COS analysis showed that lignin is easily liquefied at high temperatures and a decreasing amount of PEG, and that the presence of glycerol significantly enhanced the 1730 cm−1 band
Gastroesophageal reflux-associated chronic cough in an adolescent and the diagnostic implications: a case report
A 15-year-old girl was referred with a 2-year history of perennial non-productive cough, which had been preceded by Mycoplasma pneumoniae pneumonia and subsequent asthma. Symptoms were only partially responsive to anti-asthma treatment including an inhaled corticosteroid and a leukotriene receptor antagonist. The patient's BMI was 27.8; she had gained over 10 kg in the previous two years. Typical symptoms of gastroesophageal reflux disease were not evident except for belch. Coughing worsened on eating and rising from bed. Although esophagography failed to disclose reflux esophagitis, esophageal pH monitoring revealed significant acid reflux. Asthma was considered well controlled. Treatment with the proton-pump inhibitor rabeprazole resulted in disappearance of cough. Frequency Scale for the Symptoms of Gastroesophageal reflux disease (FSSG) score, a questionnaire evaluating the symptoms of gastroesophageal reflux disease, was initially high but normalized after treatment. Capsaicin cough sensitivity also diminished with treatment
上顎の形態発生におけるWnt signaling pathwayの役割
Cleft lip with or without cleft palate (CLP) usually results from a failure of the medial nasal prominences to fuse with the lateral and maxillary prominences. This failure inhibits facial morphogenesis regulated by several major morphogenetic signaling pathways. We hypothesized that CLP results from the failure of the Wnt signaling pathway. To examine whether Wnt signaling can influences upper jaw development, we applied beads soaked with Dickkopf-1 (Dkk-1), Alsterpaullone (AL) or Wnt3a to the right side of the maxillary prominence of the chick embryo. The embryo showed a defect of the maxilla on the treated side, and skeletal staining revealed hypoplasia of the premaxilla and palatine bone as a result of Dkk-1-soaked bead implantation. 5-bromo-2'-deoxyuridine (BrdU)-positive cell numbers in the treated maxillary prominence were significantly lower at both 24 and 48 hr after implantation. Down-regulation of the expression of Bmp4, Tbx22, Sox9, and Barx1 was confirmed in the maxillary prominence treated with Dkk-1, which indicated that the deformity of the maxillary bone was controlled by gene targets of the Wnt signaling pathway. Expression of N-cadherin was seen immunohistochemically in the maxillary prominences of embryos at 6 hr and increased at 24 hr after AL treatment. Wnt signaling enhanced by AL or Wnt3a up-regulated the expression levels of Msx1, Bmp4, Tbx22, Sox9, and Barx1. Our data suggest that the Wnt signaling pathway regulates maxillary morphogenesis and growth through Bmp4, Tbx22, Sox9, and Barx1. Wnt signaling might regulate N-cadherin expression via Msx1, resulting in cell aggregation for osteochondrogenesis.博士(医学)・乙第1430号・令和元年6月26日© 2019 The Japan Society of Histochemistry and CytochemistryCopyright: © 2019 The author. This is an open access article distributed under the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, istribution, and reproduction in any medium, provided the original work is properly cited.J-STAGEへのリンク : http://dx.doi.org/10.1267/ahc.1803
Prevalence and clinical manifestations of gastro-oesophageal reflux-associated chronic cough in the Japanese population
Gastro-oesophageal reflux (GOR) is one of the most common causes of chronic cough in Western countries, responsible for 10 to 40% of cases. In Japan, however, GOR-associated chronic cough (GOR-CC) has been rarely reported and its clinical manifestation including frequency of concomitant reflux laryngitis is poorly known. We have analyzed prevalence and clinical characteristics of patients who were diagnosed as having GOR-CC among adult patients with chronic cough (≥ 8 weeks) who visited our asthma and cough clinic over a period of 19 months. Diagnosis of GOR-CC was based on the response of coughing to a proton-pump inhibitor (lansoprazole™) and/or positive results of 24 h ambulatory esophageal pH monitoring. Laryngeal involvement was based on symptoms or objective diagnosis by specialists. GOR-associated chronic cough was diagnosed in 7.1% (8 of 112) of chronic cough patients. In addition to the demographic data which were consistent with the characteristics of patients with GOR-CC in the Western populations, including gender (6 females), age (mean ± SE, 56.9 ± 5.8 years), duration of cough (9.9 ± 3.3 months), lack of gastrointestinal symptoms (3 of 8) and complication with other causes of cough (5 of 8), we found the standard range of body mass index (23.9 ± 1.5 kg/m(2)) and high incidence of concomitant reflux laryngitis (5 of 8) in the present 8 patients. Among 4 patients who could stop treatment with temporal resolution of cough, cough recurred in 3 patients, 1 week to 8 months after the discontinuation. In conclusion, GOR-CC is a less frequent cause of chronic cough in Japan than in Western countries. Signs or symptoms of laryngitis may be important as clues to suspicion of GOR-CC
Features of cough variant asthma and classic asthma during methacholine-induced brochoconstriction: a cross-sectional study
[Background]Little is known regarding mechanistic and phenotypic differences between cough variant asthma (CVA), presenting with a chronic cough as the sole symptom that responds to bronchodilators, and classic asthma with wheezing during methacholine inhalation. Here we reported airway sensitivity, airway reactivity, and as the main concern, the appearance of cough and wheezes during methacholine inhalation in patients with CVA or classic asthma. [Methods]We cross-sectionally examined the degrees of airway sensitivity, the point where resistance started to increase, and reactivity, the slope of the methacholine-resistance curve, and the appearance of cough and wheezes in steroid-naive adult patients with classic asthma (n = 58) or CVA (n = 55) while they were continuously inhaling methacholine during simultaneous measurement of respiratory resistance. [Results]Patients with CVA were less sensitive and less reactive to inhaled methacholine and wheezed less frequently but coughed more frequently during methacholine-induced bronchoconstriction than did patients with classic asthma. Multivariate analysis revealed that airway hypersensitivity and lower baseline FEV1/FVC were associated with the appearance of wheezes, whereas a diagnosis of CVA was associated with coughing. [Conclusion]There are mechanistic and phenotypic differences between CVA and classic asthma during methacholine inhalation. Frequent coughing during bronchoconstriction may be a distinctive feature of CVA
Spared nerve injury後のマウス後根神経節におけるNGFとBDNFの発現
Neuropathic pain is initiated by a primary lesion in the peripheral nervous system and spoils quality of life. Neurotrophins play important roles in the development and transmission of neuropathic pain. There are conflicting reports that the dorsal root ganglion (DRG) in an injured nerve contribute to neuropathic pain, whereas several studies have highlighted the important contribution of the DRG in a non-injured nerve. Clarifying the role of neurotrophins in neuropathic pain is problematic because we cannot distinguish injured and intact neurons in most peripheral nerve injury models. In the present study, to elicit neuropathic pain, we used the spared nerve injury (SNI) model, in which injured DRG neurons are distinguishable from intact ones, and mechanical allodynia develops in the intact sural nerve skin territory. We examined nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in the DRGs of SNI model mice. NGF and BDNF levels increased in the injured L3 DRG, while NGF decreased in the intact L5 DRG. These data offer a new point of view on the role of these neurotrophins in neuropathic pain induced by peripheral nerve injury.博士(医学)・甲第698号・平成31年3月15日© 2018 Elsevier B.V. All rights reserved
Diagnostic utility of fractional exhaled nitric oxide in prolonged and chronic cough according to atopic status
AbstractBackgroundCough-variant asthma (CVA) and cough-predominant asthma (CPA) are the major causes of persistent cough in Japan. The utility of fractional exhaled nitric oxide (FeNO) measurement in the differential diagnosis of persistent cough has been reported, but the influence of atopic status, which is associated with higher FeNO levels, on the diagnostic utility of FeNO has been unknown.MethodsWe retrospectively analyzed 105 non-smoking patients with prolonged and chronic cough that were not treated with corticosteroids and anti-leukotrienes.ResultsCPA was diagnosed in 37 patients, CVA in 40, and non-asthmatic cough (NAC) in 28. FeNO levels were significantly higher in the CPA [35.8 (7.0–317.9) ppb] and CVA [24.9 (3.1–156.0) ppb] groups than in the NAC group [18.2 (6.9–49.0) ppb] (p < 0.01 by Kruskal–Wallis test). The optimal cut-off for distinguishing asthmatic cough (AC; CPA and CVA) from NAC was 29.2 ppb [area under the curve (AUC) 0.74, p < 0.01]. Ninety-one percent of subjects with FeNO levels ≥29.2 ppb had AC. Meanwhile, 40% of AC patients had FeNO levels <29.2 ppb. Stratified cut-off levels were 31.1 ppb (AUC 0.83) in atopic subjects vs. 19.9 ppb (AUC 0.65) in non-atopic subjects (p = 0.03 for AUC).ConclusionsAlthough high FeNO levels suggested the existence of AC, lower FeNO levels had limited diagnostic significance. Atopic status affects the utility of FeNO levels in the differential diagnosis of prolonged and chronic cough
Effects of NCO/OH Ratios on Bio-Based Polyurethane Film Properties Made from Acacia mangium Liquefied Wood
The compatibility between isocyanate and polyol plays an important role in determining a polyurethane product’s performance. This study aims to evaluate the effect of varying the ratios between polymeric methylene diphenyl diisocyanate (pMDI) and Acacia mangium liquefied wood polyol on the polyurethane film properties. A. mangium wood sawdust was liquefied in polyethylene glycol/glycerol co-solvent with H₂SO₄ as a catalyst at 150 ◦C for 150 min. The A. mangium liquefied wood was mixed with pMDI with difference NCO/OH ratios to produce film through the casting method. The effects of the NCO/OH ratios on the molecular structure of the PU film were examined. The formation of urethane, which was located at 1730 cm⁻¹, was confirmed via FTIR spectroscopy. The TGA and DMA results indicated that high NCO/OH ratios increased the degradation temperature and glass transition from 275 ◦C to 286 ◦C and 50 ◦C to 84 ◦C, respectively. The prolonged heat appeared to boost the crosslinking density of the A. mangium polyurethane films, which finally resulted in a low sol fraction. From the 2D-COS analysis, the hydrogen-bonded carbonyl (1710 cm⁻¹) had the most significant intensity changes with the increasing NCO/OH ratios. The occurrence of the peak after 1730 cm⁻¹ revealed that there was substantial formation of urethane hydrogen bonding between the hard (PMDI) and soft (polyol) segments as the NCO/OH ratios increased, which gave higher rigidity to the film
Biodegradability properties of polyurethane film made from Eucalyptus pellita wood polyol
The properties of polyurethane (PU) film are greatly influenced not only by the raw materials but also by the compatibility of polyol and isocyanate. This paper aimed to evaluate the effect of the isocyanate index (NCO/OH ratio) on the biodegradability properties of Eucalyptus pellita PU film. E. pellita wood polyol and polymeric methylene diphenyl diisocyanate (pMDI) were mixed at different NCO/OH ratios (1.8 – 3.0). The PU film was produced through the one-shot method. The effect of the NCO/OH ratio on the biodegradability properties of PU film was evaluated. The rate of biodegradation of PU film by soil burial test decreases proportionally to the NCO/OH ratio. The biodegradation rate is the highest (14.02%) when the NCO/OH ratio is the lowest (1.8). The results of water solubility showed that PU films with low NCO/OH ratios are easily soluble in water. The band associated with the ester compound was detected at nearly 1,060 cm−1. Based on the findings of this study, increasing the NCO/OH ratio made the PU film from E. pellita less degradable. Therefore, lowering the NCO/OH ratio is an ideal option to produce films with better biodegradabilit
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