Metabolic role of pyrophosphate-linked phosphofructokinasepfkfor C1 assimilation inMethylotuvimicrobium alcaliphilum20Z

Background Methanotrophs is a promising biocatalyst in biotechnological applications with their ability to utilize single carbon (C1) feedstock to produce high-value compounds. Understanding the behavior of biological networks of methanotrophic bacteria in different parameters is vital to systems biology and metabolic engineering. Interestingly, methanotrophic bacteria possess the pyrophosphate-dependent 6-phosphofructokinase (PPi-PFK) instead of the ATP-dependent 6-phosphofructokinase, indicating their potentials to serve as promising model for investigation the role of inorganic pyrophosphate (PPi) and PPi-dependent glycolysis in bacteria. Gene knockout experiments along with global-omics approaches can be used for studying gene functions as well as unraveling regulatory networks that rely on the gene product. Results In this study, we performed gene knockout and RNA-seq experiments inMethylotuvimicrobium alcaliphilum20Z to investigate the functional roles of PPi-PFK in C1 metabolism when cells were grown on methane and methanol, highlighting its metabolic importance in C1 assimilation inM. alcaliphilum20Z. We further conducted adaptive laboratory evolution (ALE) to investigate regulatory architecture inpfkknockout strain. Whole-genome resequencing and RNA-seq approaches were performed to characterize the genetic and metabolic responses of adaptation topfkknockout. A number of mutations, as well as gene expression profiles, were identified inpfkALE strain to overcome insufficient C1 assimilation pathway which limits the growth in the unevolved strain. Conclusions This study first revealed the regulatory roles of PPi-PFK on C1 metabolism and then provided novel insights into mechanism of adaptation to the loss of this major metabolic enzyme as well as an improved basis for future strain design in type I methanotrophs

ICAR: endoscopic skull‐base surgery

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Time-resolved resonance Raman and density functional theory investigation of the 4-biphenylnitrene dimerization reaction

This paper reports time-resolved resonance Raman spectra for the triplet 4-biphenylnitrene and its reaction to form an azo dimer product (bis-biphenyl-4-yldiazene) in acetonitrile solution. The properties of the triplet 4-biphenylnitrenes were examined based on the results of UBPW91/cc-PVDZ computations. 4-Biphenylnitrene and its azo dimer product were also compared with results previously reported for the 4-methoxyphenylnitrene and its azo dimer product, respectively. The substitution effect of p-phenyl and p-methoxy moieties on the structure and properties of arylnitrenes and azobenzenes are briefly discussed. Copyright © 2004 John Wiley & Sons, Ltd.link_to_subscribed_fulltex

Time-resolved resonance Raman and density functional theory investigation of the 4-biphenylnitrene dimerization reaction

This paper reports time-resolved resonance Raman spectra for the triplet 4-biphenylnitrene and its reaction to form an azo dimer product (bis-biphenyl-4-yldiazene) in acetonitrile solution. The properties of the triplet 4-biphenylnitrenes were examined based on the results of UBPW91/cc-PVDZ computations. 4-Biphenylnitrene and its azo dimer product were also compared with results previously reported for the 4-methoxyphenylnitrene and its azo dimer product, respectively. The substitution effect of p-phenyl and p-methoxy moieties on the structure and properties of arylnitrenes and azobenzenes are briefly discussed. Copyright © 2004 John Wiley & Sons, Ltd.link_to_subscribed_fulltex

A prospective randomized trial with 7-day nitrofurantoin-moxifloxacin containing regime for highly resistant Helicobacter pylori infection

Poster Session - H. Pylori 3: abstract no. P1632Theme: Our birthday event marked by record numbersINTRODUCTION/OBJECTIVES: Limited treatment options are available for patients infected with resistant Helicobacter pylori, who failed to achieve eradication after the first line clarithromycin containing triple therapy and the second line quadruple therapy. The aim of this randomized trial is to compare the efficacy and tolerability of H. pylori eradication with a nitrofurantoin-moxifloxacin-containing regime against the control by repeating the quadruple thera…link_to_OA_fulltex

Standard clarithromycin-based triple therapy is superior to levofloxacin-based triple therapy as first-line treatment for Helicobacter pylori eradication in a Chinese population

AGA Abstract No. 978link_to_subscribed_fulltex

Ten day sequential versus 10 day modified bismuth quadruple therapy as empirical firstline and secondline treatment for Helicobacter pylori in Chinese patients: an open label, randomised, crossover trial

OBJECTIVE: Treatments with sequential therapy (SEQ) or bismuth quadruple (QUAD) therapy have been proposed as empirical firstline regimens for Helicobacter pylori. We compared the efficacy and tolerability of 10 day SEQ with 10 day modified QUAD as both firstline and secondline treatments for H pylori in a randomised crossover study. DESIGN: H pylori positive and treatment naive patients were randomly assigned to receive either 10 day SEQ (esomeprazole for 10 days, amoxicillin for an initial 5 days, followed by clarithromycin and metronidazole for a subsequent 5 days) or modified QUAD (esomeprazole, bismuth subcitrate, tetracycline and metronidazole). H pylori eradication was confirmed by urea breath test at 8 weeks. Patients who failed the initial assigned treatment were crossed over to receive the alternate regimen. The primary outcome was eradication rates of firstline treatment by intention to treat (ITT) and per protocol (PP) analyses. RESULTS: 357 patients were randomised to receive either SEQ or QUAD. The PP eradication rates of the SEQ and QUAD groups were 95.2% and 98.8%, respectively (p=0.10). Based on ITT analysis, the corresponding eradication rates were 89.4% and 92.7%, respectively (p=0.36). Eight (4.8%) patients in the SEQ and two (1.2%) patients in the QUAD who failed the firstline treatment were crossed over to the alternate regimen with 100% retreatment success. The overall incidence of adverse events was higher in the QUAD (16.7%) than in the SEQ (8.1%; p=0.032) group. CONCLUSIONS: Ten day sequential and modified bismuth quadruple therapies are both highly effective as empirical firstline therapies for H pylori in Chinese patients. CLINICALTRIALS.GOV: NCT 01760824