896 research outputs found
N-(1H-1,2,3-Benzotriazol-1-ylmethyl)phthalimide
The title compound [systematic name: 2-(1H-1,2,3-benzotriazol-1-ylmethyl)isoindole-1,3-dione], C15H10N4O2, was prepared by the reaction of 1H-benzotriazole and 2-bromomethylisoindole-1,3-dione. The benzotriazole and isoindole units are almost planar and make a dihedral angle of 70.2 (1)° (mean planes include C and N atoms). A weak C—H⋯O intramolecular hydrogen bond involving a carbonyl O atom as acceptor stabilizes the observed molecular conformation
PERFORMANCE COMPARISON OF SYNGAS METHANATION ON FLUIDIZED AND FIXED BED REACTORS
The performance was compared on Syngas Completely Methanation at atmospheric pressure on fluidized and fixed bed reactors. From space-time yield of CH4, coke content and hot spots of bed temperature, fluidized bed technology was demonstrated to be more applicable to Syngas Completely Methanation. Characterization results showed that different carbon deposition forms were presented on the two operation modes
Antibiotic Resistomes in Plant Microbiomes
Microorganisms associated with plants may alter the traits of the human microbiome important for human health, but this alteration has largely been overlooked. The plant microbiome is an interface between plants and the environment, and provides many ecosystem functions such as improving nutrient uptake and protecting against biotic and abiotic stress. The plant microbiome also represents a major pathway by which humans are exposed to microbes and genes consumed with food, such as pathogenic bacteria, antibiotic-resistant bacteria, and antibiotic-resistance genes. In this review we highlight the main findings on the composition and function of the plant microbiome, and underline the potential of plant microbiomes in the dissemination of antibiotic resistance via food consumption or direct contact
Applicability of Perturbative QCD to Pion Virtual Compton Scattering
We study explicitly the applicability of perturbative QCD (pQCD) to the pion
virtual Compton scattering. It is found that there are central-region
singularities introduced by the QCD running coupling constant, in addition to
the end-point singularities generally existed in other exclusive processes such
as the pion form factor. We introduce a simple technique to evaluate the
contributions from these singularities, so that we can arrive at a judgement
that these contributions will be unharmful to the applicability of pQCD at
certain energy scale, i.e., the ``work point'' which is defined to determine
when pQCD is applicable to exclusive processes. The applicability of pQCD for
different pion distribution amplitudes are explored in detail. We show that
pQCD begins to work at 10 . If we relax our constraint to a weak
sense, the work point may be as low as 4 .Comment: 13 Latex pages, 10 figures, to appear in PL
Backreaction in Axion Monodromy, 4-forms and the Swampland
Axion monodromy models can always be described in terms of an axion coupled
to 3-form gauge fields with non-canonical kinetic terms. The presence of the
saxions parametrising the kinetic metrics of the 3-form fields leads to
backreaction effects in the inflationary dynamics. We review the case in which
saxions backreact on the K\"ahler metric of the inflaton leading to a
logarithmic scaling of the proper field distance at large field. This behaviour
is universal in Type II string flux compactifications and consistent with a
refinement of the Swampland Conjecture. The critical point at which this
behaviour appears depends on the mass hierarchy between the inflaton and the
saxions. However, in tractable compactifications, such a hierarchy cannot be
realised without leaving the regime of validity of the effective theory,
disfavouring transplanckian excursions in string theory.Comment: Proceedings prepared for the "Workshop on Geometry and Physics",
November 2016, Ringberg Castl
AsChip:A High-Throughput qPCR Chip for Comprehensive Profiling of Genes Linked to Microbial Cycling of Arsenic
Arsenic (As) is a ubiquitous toxic
element adversely affecting
human health. Microbe-mediated cycling of As is largely mediated by
detoxification and energy metabolism in microorganisms. We here report
the development of a novel high-throughput qPCR (HT-qPCR) chip (AsChip)
for comprehensive profiling of genes involved in microbial As cycling
(here collectively termed “As genes”). AsChip contained
81 primer sets targeting 19 As genes and the 16S rRNA gene as a reference
gene. Gene amplicon sequencing showed high identity (>96%) of newly
designed primers corresponding to their targets. AsChip displayed
high sensitivity (plasmid template serial dilution test; r = −0.99), with more than 96% of all PCR assays yielding true
positive signals. R2 coefficients for
standard curves and PCR amplification efficiencies averaged 0.98 and
0.99, respectively. A high correlation between CT values
obtained by AsChip and conventional qPCR was obtained (r = 0.962, P < 0.001). Finally, we successfully
applied AsChip on soil samples from a chromium–copper–arsenic-contaminated
field site and identified diverse As genes with total abundance average
of 0.4 As gene copies per 16S rRNA. Our results indicate that AsChip
constitutes a robust tool for comprehensive quantitative profiling
of As genes in environmental samples
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Omega-3 Polyunsaturated Fatty Acids Protect Neural Progenitor Cells against Oxidative Injury
The omega-3 polyunsaturated fatty acids (ω-3 PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), derived mainly from fish oil, play important roles in brain development and neuroplasticity. Here, we reported that application of ω-3 PUFAs significantly protected mouse neural progenitor cells (NPCs) against H2O2-induced oxidative injury. We also isolated NPCs from transgenic mice expressing the Caenorhabditis elegans fat-1 gene. The fat-1 gene, which is absent in mammals, can add a double bond into an unsaturated fatty acid hydrocarbon chain and convert ω-6 to ω-3 fatty acids. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining showed that a marked decrease in apoptotic cells was found in fat-1 NPCs after oxidative injury with H2O2 as compared with wild-type NPCs. Quantitative RT-PCR and Western blot analysis demonstrated a much higher expression of nuclear factor erythroid 2-related factor 2 (Nrf2), a master transcriptional factor for antioxidant genes, in fat-1 NPCs. The results of the study provide evidence that ω-3 PUFAs resist oxidative injury to NPCs
Loss of soil microbial diversity exacerbates spread of antibiotic resistance
Loss of biodiversity is a major threat to the ecosystem processes upon which society depends. Natural ecosystems differ in their resistance to invasion by alien species, and this resistance can depend on the diversity in the system. Little is known, however, about the barriers that microbial diversity provides against microbial invasion. The increasing prevalence of antibiotic-resistant bacteria is a serious threat to public health in the 21st century. We explored the consequences of the reduction in soil microbial diversity for the dissemination of antibiotic resistance. The relationship between this diversity and the invasion of antibiotic resistance was investigated using a dilution-to-extinction approach coupled with high-capacity quantitative PCR. Microbial diversity was negatively correlated with the abundance of antibiotic-resistance genes, and this correlation was maintained after accounting for other potential drivers such as incubation time and microbial abundance. Our results demonstrate that high microbial diversity can act as a biological barrier resist the spread of antibiotic resistance. These results fill a critical gap in our understanding of the role of soil microbial diversity in the health of ecosystem
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