17 research outputs found
Agricultural nonpoint source pollutant loads into water bodies in a typical basin in the middle reach of the Yangtze River
Phosphorus and nitrogen pollution from agricultural nonpoint sources heavily burden the water environment, and a scientific calculating system is needed to calculate the pollutant loads under the water pollution treatment. This study established a system to calculate the coefficients of agricultural nonpoint source pollutants into water bodies in the subregion in Poyang Lake basin in the middle reach of the Yangtze River combining with multiple driving factors. Validation results showed that the errors of the typical unit were 30.58% for total phosphorus (TP), 13.43% for total nitrogen (TN) and 33.93% for ammonia nitrogen (NH3-N), respectively. The errors of the subregion were 26.92% for TP, 31.83% for TN and 29.15% for NH3-N, respectively. Besides, there were higher TP and TN loads in the east area of subregion in both units and county scales, which indicated the heavy phosphorus and nitrogen burden on water environment. In contrast, higher NH3-N loads occurred in the north area of subregion. The establishment of coefficient system for agricultural pollutants into water bodies and the pollutant loads calculation would provide enlightenment for water pollution treatment and agricultural nonpoint source pollution controlling
Synthesis and Structure of a Propeller-Shaped Polycyclic Aromatic Hydrocarbon Containing Seven-Membered Rings
The
synthesis and structure of a <i>C</i><sub>3</sub>-symmetric
propeller-shaped polycyclic aromatic hydrocarbon that
bears three seven-membered rings is reported. The synthesis was accomplished
in three steps from benzoÂ[<i>c</i>]ÂnaphthoÂ[2,1-<i>p</i>]Âchrysene, including a Pd-catalyzed intramolecular
C–H arylation for the formation of the seven-membered rings.
The combination of the helicities (<i>P</i>/<i>M</i>) of the three seven-membered-ring moieties and three [4]Âhelicene
moieties affords 24 possible conformers, and two relatively stable
conformations were observed by <sup>1</sup>H NMR spectroscopy
Geochemical Characteristics of Rare Earth Elements in Soils from Puding Karst Critical Zone Observatory, Southwest China
Synthesis and Structure of a Propeller-Shaped Polycyclic Aromatic Hydrocarbon Containing Seven-Membered Rings
The
synthesis and structure of a <i>C</i><sub>3</sub>-symmetric
propeller-shaped polycyclic aromatic hydrocarbon that
bears three seven-membered rings is reported. The synthesis was accomplished
in three steps from benzoÂ[<i>c</i>]ÂnaphthoÂ[2,1-<i>p</i>]Âchrysene, including a Pd-catalyzed intramolecular
C–H arylation for the formation of the seven-membered rings.
The combination of the helicities (<i>P</i>/<i>M</i>) of the three seven-membered-ring moieties and three [4]Âhelicene
moieties affords 24 possible conformers, and two relatively stable
conformations were observed by <sup>1</sup>H NMR spectroscopy
Mycobacterium Tuberculosis-Specific TNF-α Is a Potential Biomarker for the Rapid Diagnosis of Active Tuberculosis Disease in Chinese Population
<div><p>Interferon-gamma release assays (IGRAs) have proven to be useful to accurately detect <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>) infection, but they cannot reliably discriminate between active tuberculosis (TB) and latent tuberculosis infection (LTBI). This study aims to test whether <i>Mtb</i>-specific tumor necrosis factor-alpha (TNF-α) could be used as a new tool for the rapid diagnosis of active TB disease. The secretion of TNF-α by <i>Mtb</i>-specific antigen-stimulated peripheral blood mononuclear cells (PBMCs) of sixty seven participants was investigated in the study. Our results showed that the total measurement of TNF-α secretion by <i>Mtb</i>-specific antigen-stimulated PBMCs is not a good biomarker for active TB diagnosis. However, we found that calculation of <i>Mtb</i>-specific TNF-α not only distinguish between active and latent TB infection, but also can differentiate active TB from non-TB patients. Using the cutoff value of 136.9 pg/ml for <i>Mtb</i>-specific TNF-α, we were able to differentiate active TB from LTBI. Sensitivity and specificity were 72% and 90.91%. These data suggest that <i>Mtb</i>-specific TNF-α could be a potential biomarker for the diagnosis of active TB disease.</p></div
The secretions of TNF-α and <i>Mtb</i>-specific TNF-α by ESAT-6 or CFP-10-stimulated PBMCs.
<p>PBMCs obtained from active TB patients (n = 25), LTBI individuals (n = 22), healthy control subjects (n = 10) and non-TB patients (n = 10) were stimulated with ESAT-6 or CFP-10. PBMCs stimulated with medium alone were used as a background control. (A) After 16–20 h of incubation, the supernatant was collected and tested for concentrations of secreted TNF-α by ELISA. (B) <i>Mtb</i>-specific TNF-α was calculated by subtracting background TNF-α secreted by medium-stimulated PBMCs from TNF-α secreted by ESAT-6 or CFP-10-stimulated PBMCs. Median values for each group of participants are represented by a horizontal bar. *<i>p</i> < 0.05, **<i>p</i> < 0.001.</p
Statistical analysis of ROC curve for <i>Mtb</i>-specific TNF-α to distinguish between active TB and LTBI.
<p>Note. TB: tuberculosis; LTBI: latent tuberculosis infection; AUC: area under the curve.</p
The cytotoxicity of ESAT-6 to PHA-stimulated PBMCs of three non-TB patients.
<p>Note. PHA: phytohemagglutinin; TB: tuberculosis; AFS: acid fast staining.</p