No abstract

Bradyrhizobia are common members of soil microbiomes and known as N 2 -fixing symbionts of economically important legumes. Many are also denitrifiers, which can act as sinks or sources for N 2 O. Inoculation with compatible rhizobia is often needed for optimal N 2 -fixation, but the choice of inoculant may have consequences for N 2 O emission. Here, we determined the phylogeny and denitrification capacity of Bradyrhizobium strains, most of them isolated from peanut-nodules. Analyses of genomes and denitrification end-points showed that all were denitrifiers, but only $1/3 could reduce N 2 O. The N 2 O-reducing isolates had strong preference for N 2 Oover NO 3 − -reduction. Such preference was also observed in a study of other bradyrhizobia and tentatively ascribed to competition between the electron pathways to Nap (periplasmic NO 3 − reductase) and Nos (N 2 O reductase). Another possible explanation is lower abundance of Nap than Nos. Here, proteomics revealed that Nap was instead more abundant than Nos, supporting the hypothesis that the electron pathway to Nos outcompetes that to Nap. In contrast, Paracoccus denitrificans, which has membrane-bond NO 3 − reductase (Nar), reduced N 2 O and NO 3 − simultaneously. We propose that the control at the metabolic level, favouring N 2 O reduction over NO 3 − reduction, applies also to other denitrifiers carrying Nos and Nap but lacking Nar.

Shielding materials are becoming increasingly important, but present materials suffer from either insufficient mechanical stability or limited shielding properties. In this study, 3D flexible copper sulfide (CuxS)/polyacrylonitrile (PAN) nanofiber mats are developed via air spinning followed by chemical reaction with copper salt. The CuxS/PAN nanofiber mats exhibit an ultra‐lightweight density of 0.044 g cm−3 and a thickness of 0.423 mm. Stable electromagnetic interference (EMI) shielding effectiveness (SE) (29–31 dB) of the CuxS/PAN composite is achieved in the frequency range of 500–3000 MHz. EMI SE per unit surface density of 16 655.92 dB cm2 g−1 is several orders of magnitude higher than most copper sulfide containing EMI shielding materials reported in literature. In addition, the introduction of the CuxS improves the thermal stability and launderability of the PAN mats giving the mats thermal, mechanical, and aqueous stability. Finally, the shielding mechanism of the CuxS/PAN nanofiber mats for electromagnetic waves is proposed

BackgroundTo better define the clinicopathologic characteristics of signet ring cell (SRC) gastric cancer and build a prognostic model for it.MethodsSRC patient information from 2010 to 2015 were identified using Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier method and log-rank test were used to estimate Overall survival (OS) and to determine associations with histologic subtypes. In COX proportional hazards regression model–based univariate and multivariate analyses, significant variables for construction of a nomogram were screened out. The nomogram was validated by means of the concordance index (CI), calibration plots, and receiver operating characteristics (ROCs) curves.ResultsA total of 11,363 gastric cancer patients were enrolled. On dividing the patients into SRC, well-to-moderately differentiated (WMD) adenocarcinoma, and poorly differentiated (PD) adenocarcinoma, differences among these subgroups emerged. SRC patients were more likely to occur in female and young patients than other histologic subtypes. Larger tumors, stage T4, and node stage N3 were more likely to be found in the SRC group. The survival for SRC patients was better than non-SRC patients in stage I. Univariate and multivariate analyses identified age, tumor site, larger tumor size, advanced T classification, advanced N classification, advanced TNM stage, and surgery of primary site as independent prognostic indicators. Then an OS nomogram was formulated.ConclusionsSRC had distinct clinicopathological characteristics. The nomogram provided an accurate tool to evaluate the prognosis of SRC.

No abstract