Non-Invasive Mapping of the Gastrointestinal Microbiota Identifies Children with Inflammatory Bowel Disease

Background: Pediatric inflammatory bowel disease (IBD) is challenging to diagnose because of the non-specificity of symptoms; an unequivocal diagnosis can only be made using colonoscopy, which clinicians are reluctant to recommend for children. Diagnosis of pediatric IBD is therefore frequently delayed, leading to inappropriate treatment plans and poor outcomes. We investigated the use of 16S rRNA sequencing of fecal samples and new analytical methods to assess differences in the microbiota of children with IBD and other gastrointestinal disorders. Methodology/Principal Findings: We applied synthetic learning in microbial ecology (SLiME) analysis to 16S sequencing data obtained from i) published surveys of microbiota diversity in IBD and ii) fecal samples from 91 children and young adults who were treated in the gastroenterology program of Children’s Hospital (Boston, USA). The developed method accurately distinguished control samples from those of patients with IBD; the area under the receiver-operating-characteristic curve (AUC) value was 0.83 (corresponding to 80.3% sensitivity and 69.7% specificity at a set threshold). The accuracy was maintained among data sets collected by different sampling and sequencing methods. The method identified taxa associated with disease states and distinguished patients with Crohn’s disease from those with ulcerative colitis with reasonable accuracy. The findings were validated using samples from an additional group of 68 patients; the validation test identified patients with IBD with an AUC value of 0.84 (e.g. 92% sensitivity, 58.5% specificity). Conclusions/Significance: Microbiome-based diagnostics can distinguish pediatric patients with IBD from patients with similar symptoms. Although this test can not replace endoscopy and histological examination as diagnostic tools, classification based on microbial diversity is an effective complementary technique for IBD detection in pediatric patients.Natural Sciences and Engineering Research Council of Canada (Award NSERC PGS D)National Institutes of Health (U.S.) (1-R21-A1084032-01A1

Structure and properties of oxidatively stabilized viscose rayon fibers impregnated with boric acid and phosphoric acid prior to carbonization and activation steps

The role of boric acid-phosphoric acid (BA-PA) impregnation and oxidation on the structure and properties of viscose rayon fibers was examined in air at temperatures ranging from 150 to 250 A degrees C. The results obtained from the measurements of fiber thickness, linear density, X-ray diffraction, thermal analysis (DSC and TGA), and infrared spectroscopy demonstrated that oxidation temperature had a significant influence on the structure and properties of oxidized viscose rayon fibers. Physical transformations were characterized by fiber thickness and linear density values together with color variations and improved burning behavior with progressing oxidation temperature. The DSC analysis showed that BA-PA impregnation enhanced thermal stability and prevented the evolution of volatile by-products by blocking the primary hydroxyl groups. TGA thermograms revealed an enhancement in the char yields. X-ray diffraction analysis showed the loss of cellulose II crystalline structure caused by the decrystallization process initiated by the gradual loss of intermolecular hydrogen bonds. Analysis of IR spectra revealed gradual and continuous loss of intramolecular and intermolecular hydrogen bonding as part of the simultaneously occurring dehydrogenation and dehydration reactions. Analysis of IR data also demonstrated the disturbance of the cellulose II crystalline structure with increasing oxidation temperature in agreement with the results obtained from X-ray diffraction measurements. The formation of C=C bonds attributed to the crosslinked ladder-like structure was also confirmed by the IR spectra.The role of boric acid–phosphoric acid (BA–PA) impregnation and oxidation on the structure and properties of viscose rayon fibers was examined in air at temperatures ranging from 150 to 250 C. The results obtained from the measurements of fiber thickness, lineardensity, X-ray diffraction, thermal analysis (DSC and TGA), and infrared spectroscopy demonstrated that oxidation temperature had a significant influence on the structure and properties of oxidized viscose rayon fibers. Physical transformations were characterized by fiber thickness and linear density values together with color variations and improved burning behavior with progressing oxidation temperature. The DSC analysis showed that BA–PA impregnation enhanced thermal stability and prevented the evolution of volatile by-products by blocking the primary hydroxyl groups. TGA thermograms revealed an enhancement in the char yields. X-ray diffraction analysis showed the loss of cellulose II crystalline structure caused by the decrystallization process initiated by the gradual lossof intermolecular hydrogen bonds. Analysis of IR spectra revealed gradual and continuous loss of intramolecular and intermolecular hydrogen bonding as part of the simultaneouslyoccurring dehydrogenation and dehydration reactions.Analysis of IR data also demonstrated the disturbance of the cellulose II crystalline structure with increasing oxidation temperature in agreement with the results obtained from X-ray diffraction measurements. The formation of C=C bonds attributed to the crosslinked ladder-like structure was also confirmed by the IR spectra