The Effect of Preozonation on the Anaerobic Biodegradability of Resistant Phenolic Compounds

Ozone pretreatment studies of four model phenolic compounds were conducted to evaluate the effects of ozonation on the anaerobic biodegradability and toxicity of these compounds. Two types of batch studies, the Biochemical Methane Potential (BMP) and the Anaerobic Toxicity Assay (ATA), were performed on samples ozonated upon phenol, o-cresol, 2,5-dichlorophenol, and 2,4-dinitrophenol. Experimental results showed that toxic and refractory phenolic compounds were converted to methane gas by means of preozonation. In general, the biodegradable fraction of the oxidation products increased as the ozone dose was increased. However, ozonation to achieve at least 60% COD reduction was necessary to faciliate methane production. Ozonation reduced the toxicity of 2,5-DCP and 2,4-DNP on both acetate utilization and phenol degradation. The early ozonation products of o-cresol and phenol, however, were more toxic than the initial compounds. The rates of COD and DOC reduction through ozonation were faster and products formed were less inhibitory in the basic pH range than in the acid pH range

Microbial attachment properties in expanded-bed, activated carbon anaerobic filters

A completely mixed, expanded-bed, anaerobic granular activated carbon filter was operated on synthetic wastewaters in which acetate was the only organic carbon source. Steady-state performance was achieved for two influent acetate concentrations: namely, 800 and 1,600 mg/L. Steady-state removal efficiencies in chemical oxygen demand, dissolved organic carbon, and acetate exceeding 96, 97, and 98 percent were obtained, respectively. A steady-state biofilm kinetic model was employed for analyzing the two sets of "steady-state" data. The modeling effort was successful in describing trends and effects; however, insufficient data were available to properly calibrate the model and obtain reliable values for the parametric constants.U.S. Department of the InteriorU.S. Geological SurveyOpe

Effects of Aromatic Concentration on Methane Fermentation

The anaerobic biodegradability and toxicity of fourteen aromatic compounds were evaluated over a wide range of concentrations using a serum bottle technique. Benzene, toluene, and all three isomers of xylene were not significantly degraded to methane in a phenol-enriched culture. Complete degradation of 1000 mg/L phenol, 800 mg/L catechol, 100 mg/L 2-NP, 100 mg/L 3- NP, and 100 mg/L 4-NP was observed within two months while depletion of 100 mg/L resorcinol and 1000 mg/L hydroquinone required more than six and eight months incubation, respectively. None of the three isomers of chlorophenol were degraded in the phenol-enriched culture. Batch toxicity assay revealed that the phenol-enriched culture was more susceptible to inhibition caused by substituted phenols than the acetate-enriched culture. In general, the inhibitory effects on both phenol degradation and acetate utilization did not vary significantly with the isomer but rather with the substituted group. The degree of inhibition was in the order of nitrophenols \u3e chlorophenols \u3e hydroxyphenols. The Haldane inhibition model was used to fit experimental data from phenol and catechol. The inhibition of phenol degradation by chlorophenols, resorcinol, and hydroquinone was described rather well by a Monod-type, noncompetitive model

Comparison of Antimicrobial Susceptibility Testing of Isolates from Blood Cultures by Direct Inoculation Method and PHOENIX

Background: Bloodstream infection (BSI) is an important cause of serious morbidity and mortality for hospitalized patients. Empirically Gram stain of bacteria gives the first clue for the etiology of infection and medical treatment. But the delayed treatment on 1 or 2 days after phenotypic identification and drug susceptibility testing may cause potential danger to patients. Rapid drug susceptibility testing can provide earlier information to guide treatment and in less time than bacterial culture and sensitivity testing, for antibiotics therapy. Methods: In this study, we excluded samples of polymicrobial bacteremia. We collected isolates from 815 infection episodes caused by Escherichia coli (57%), Klebsiella pneumoniae (20.16%), Enterobacter cloacae (6%), Ps.aeruginosa (9.1%), Stenotrophomonas maltophilia (3.1%), and Acinetobacter baumannii (3.1%) in a 10-month period. We identified those bacteria with direct susceptibility test with the use of Phoenix100 (BD) during a 10-month period. Results: The results of direct susceptibility were concordant (99%-100%) with those obtained from Phoenix100. Conclusion: These results have the potential to guide clinicians to initiate an early antimicrobial therapy in febrile patients with sepsis shock

Erratum to “Collagen Sponge Functionalized with Chimeric Anti-BMP-2 Monoclonal Antibody Mediates Repair of Critical-Size Mandibular Continuity Defects in a Nonhuman Primate Model”

Antibody-mediated osseous regeneration (AMOR) has been introduced by our research group as a tissue engineering approach to capture of endogenous growth factors through the application of specific monoclonal antibodies (mAbs) immobilized on a scaffold. Specifically, anti-Bone Morphogenetic Protein- (BMP-) 2 mAbs have been demonstrated to be efficacious in mediating bone repair in a number of bone defects. The present study sought to investigate the application of AMOR for repair of mandibular continuity defect in nonhuman primates. Critical-sized mandibular continuity defects were created in Macaca fascicularis locally implanted with absorbable collagen sponges (ACS) functionalized with chimeric anti-BMP-2 mAb or isotype control mAb. 2D and 3D analysis of cone beam computed tomography (CBCT) imaging demonstrated increased bone density and volume observed within mandibular continuity defects implanted with collagen scaffolds functionalized with anti-BMP-2 mAb, compared with isotype-matched control mAb. Both CBCT imaging and histologic examination demonstrated de novo bone formation that was in direct apposition to the margins of the resected bone. It is hypothesized that bone injury may be necessary for AMOR. This is evidenced by de novo bone formation adjacent to resected bone margins, which may be the source of endogenous BMPs captured by anti-BMP-2 mAb, in turn mediating bone repair

Activation of the GLP-1 receptor by a non-peptidic agonist

Class B G-protein-coupled receptors are major targets for the treatment of chronic diseases, including diabetes and obesity1. Structures of active receptors reveal peptide agonists engage deep within the receptor core, leading to an outward movement of extracellular loop 3 and the tops of transmembrane helices 6 and 7, an inward movement of transmembrane helix 1, reorganization of extracellular loop 2 and outward movement of the intracellular side of transmembrane helix 6, resulting in G-protein interaction and activation2,3,4,5,6. Here we solved the structure of a non-peptide agonist, TT-OAD2, bound to the glucagon-like peptide-1 (GLP-1) receptor. Our structure identified an unpredicted non-peptide agonist-binding pocket in which reorganization of extracellular loop 3 and transmembrane helices 6 and 7 manifests independently of direct ligand interaction within the deep transmembrane domain pocket. TT-OAD2 exhibits biased agonism, and kinetics of G-protein activation and signalling that are distinct from peptide agonists. Within the structure, TT-OAD2 protrudes beyond the receptor core to interact with the lipid or detergent, providing an explanation for the distinct activation kinetics that may contribute to the clinical efficacy of this compound series. This work alters our understanding of the events that drive the activation of class B receptors

Genome-wide trans-ancestry meta-analysis provides insight into the genetic architecture of type 2 diabetes susceptibility.

To further understanding of the genetic basis of type 2 diabetes (T2D) susceptibility, we aggregated published meta-analyses of genome-wide association studies (GWAS), including 26,488 cases and 83,964 controls of European, east Asian, south Asian and Mexican and Mexican American ancestry. We observed a significant excess in the directional consistency of T2D risk alleles across ancestry groups, even at SNPs demonstrating only weak evidence of association. By following up the strongest signals of association from the trans-ethnic meta-analysis in an additional 21,491 cases and 55,647 controls of European ancestry, we identified seven new T2D susceptibility loci. Furthermore, we observed considerable improvements in the fine-mapping resolution of common variant association signals at several T2D susceptibility loci. These observations highlight the benefits of trans-ethnic GWAS for the discovery and characterization of complex trait loci and emphasize an exciting opportunity to extend insight into the genetic architecture and pathogenesis of human diseases across populations of diverse ancestry

Genome-Wide Meta-Analysis of Five Asian Cohorts Identifies PDGFRA as a Susceptibility Locus for Corneal Astigmatism

Corneal astigmatism refers to refractive abnormalities and irregularities in the curvature of the cornea, and this interferes with light being accurately focused at a single point in the eye. This ametropic condition is highly prevalent, influences visual acuity, and is a highly heritable trait. There is currently a paucity of research in the genetic etiology of corneal astigmatism. Here we report the results from five genome-wide association studies of corneal astigmatism across three Asian populations, with an initial discovery set of 4,254 Chinese and Malay individuals consisting of 2,249 cases and 2,005 controls. Replication was obtained from three surveys comprising of 2,139 Indians, an additional 929 Chinese children, and an independent 397 Chinese family trios. Variants in PDGFRA on chromosome 4q12 (lead SNP: rs7677751, allelic odds ratio = 1.26 (95% CI: 1.16–1.36), Pmeta = 7.87×10−9) were identified to be significantly associated with corneal astigmatism, exhibiting consistent effect sizes across all five cohorts. This highlights the potential role of variants in PDGFRA in the genetic etiology of corneal astigmatism across diverse Asian populations