Search

Sepsis is a common and deadly syndrome that despite all the progress in its control, the death rate caused by it is high. Sepsis is a serious problem that needs immediate attention and treatment. This infection, especially if it is caused by bacteria resistant to several drugs, causes high mortality. About two-thirds of sepsis cases occur in hospitalized patients. Several factors such as increasing the age of the population, increasing the duration of chronic diseases, high consumption of antibiotics and corticosteroids, use of mechanical devices and intravascular devices play a role in increasing its incidence. We herein demonstrate the biogenic procedure for the in situ immobilizing gold nanoparticles over lignin (Lig)-modified Fe3O4 magnetic nanoparticles mediated by Cydonia leaf extract (Fe3O4@Lig-Ag NPs) and its catalytic activity on the acetylation of alcohols using acetic anhydride and subsequent biological performances. The successful synthesis of Fe3O4@Lig-Ag NPs was assessed using an array of advanced techniques like field emission scanning electron microscopy, fourier transformed infrared spectroscopy, transmission electron microscopy EDX, elemental mapping, vibrating-sample magnetometer, and X-ray diffraction. Cecal ligation and puncture was used for inducing the sepsis model in rats. Several doses of Fe3O4@Lig-Ag NPs (45, 15, and 5 µg/kg) on oxidant–antioxidant, inflammatory mediators mRNA such as IL-1 and TNF-α, and its effects on the levels of expression were assessed in the kidney, liver, duodenum, lung, and stomach. When septic rats kidney, liver, duodenum, lung, and stomach were compared with those of the control group, it was found that Fe3O4@Lig-Ag NPs dose-dependent administration raised glutathione levels and superoxide dismutase activity and significantly reduced the levels of malondialdehyde. The Fe3O4@Lig-Ag NPs (45 µg/kg) indicated greater anti-oxidative effects than the 5 and 15 µg/kg doses for all the assessed parameters. In addition, the expression of TNF-α mRNA in the CLP + 45 µg/kg group was decreased in comparison with the control group. Fe3O4@Lig-Ag NPs reduced oxidative stress by enhancing the free radicals scavenging effects and supporting endogenous antioxidants. The Fe3O4@Lig-Ag NPs potent antioxidant property may be related to the cytokine cascade suppression during sepsis. The above findings offer that Fe3O4@Lig-Ag NPs administration may indicate a modern treatment for the inhibition of liver, kidney, lung, duodenum, and stomach tissues damage caused by septic conditions.

Tobacco black shank (TBS) and tobacco root black rot (TRBR) are two of the most devastating tobacco soil‐borne diseases that threaten sustainable tobacco planting. This study investigated the effects of Trichoderma sp. and a resistance inducer (RI) extracted from traditional Chinese medicine, individually or in combination, on the control of TBS and TRBR. The results showed that the application of Trichoderma sp. and RI, individually or in combination, significantly controlled the two soil‐borne diseases by significantly affecting the bacterial, but not fungal, Shannon and Simpson diversity indexes. The disease indexes of TBS and TRBR in integrated application management were the lowest, resulting in the highest potassium contents in the tobacco leaves. The control efficacies of TBS and TRBR in the integrated application treatment were 71.52 ± 1.43% and 68.33 ± 0.69%, respectively. The integrated treatment altered the composition of the rhizosphere soil microbial community. The bacterial community, but not the fungal community, of the control treatment was separated from those of other treatments. The relative abundance of bacteria involved in chemoheterotrophy and fermentation in the control treatment increased, whereas that of bacteria involved in nitrification and aerobic ammonia oxidation decreased compared with the other treatments. Importantly, the application of Trichoderma sp. and RI, individually or in combination, clearly increased the relative abundance of saprotrophic fungi in contrast to the control treatment, while decreasing that of pathotrophic fungi. Our study suggests that a suitable integrated application of bioagents and RI has synergistic effects on the suppression of two tobacco soil‐borne diseases by altering the rhizosphere microbiome composition in the field. [ABSTRACT FROM AUTHOR]

Plant-growth-promoting rhizobacteria (PGPR) have been shown to relieve various biotic and abiotic stresses, but little information is available regarding their influence on germination and seedling growth of aged seeds. We isolated a promising PGPR from rescuegrass (Bromus cartharticus Vahl) roots and investigated the effect of PGPR biopriming combined with another seed priming treatment on aged rescuegrass seeds using an orthogonal matrix design with four factors. A potential ageing-repair bacterium, BCR5 (Pseudomonas geniculata), was selected from the screening trials and was identified. The reintroduction of strain BCR5 into the aged seeds pre-primed with different approaches had positive effects on germination and seedling growth. The results indicated that the bacterial cell density was the most effective factor for seed germination and vigour. Four factors were optimized for this study, including an artificial ageing duration of 54.21 h, bacterial cell density of 527.50 x [10.sup.6] CFU*[mL.sup.-1], and priming with [H.sub.2][O.sub.2] for 14.50 h, after analyzing the range and variance, and using binary quadratic regressions. Furthermore, the treatment also affected the content of malondialdehyde and the activities of superoxide dismutase and peroxidase. Bio-priming of the PGPR with another seed priming approach could be exploited as a promising technique for reinvigorating aged seeds. Moreover, we unexpectedly found that an appropriate artificial ageing treatment could break seed dormancy. Key words: plant growth-promoting rhizobacteria (PGPR), seed priming, rescuegrass, seed ageing, antioxidant enzymes. Les rhizobacteries favorisant la croissance des plantes (RFCP) s'averent attenuer differents stress biotiques et abiotiques, mais l'information disponible quant a leur influence sur la germination des semences et la croissance des pousses a partir de graines agees est rare. Les auteurs ont isole des RFCP prometteuses a partir de racines du brome cathartique (Bromus catharticus Vahl) et examine l'effet d'une pregermination biologique combinee a un autre traitement de germination physiologique des semences sur des graines agees de brome cathartique par une conception matricielle orthogonale a quatre facteurs. Une bacterie qui potentiellement remedierait au vieillissement, BCR5 (Pseudomonas geniculata), a ete identifiee et selectionnee a partir de criblages tests. La reintroduction de la souche BCR5 dans des graines agees prealablement soumises a une germination physiologique par differentes approches avait des effets positifs sur la germination et la croissance des pousses. Les resultats indiquaient que la densite cellulaire bacterienne constituait le facteur le plus efficace pour la germination et la vigueur des semences. Quatre facteurs ont ete optimises lors de cette etude, dont la duree artificielle de vieillissement de 54,21 h, la densite bacterienne de 527,50 x [10.sup.6] UFC*[mL.sup.-1], une germination physiologique par le [H.sub.2][O.sub.2] de 14,50 h a la suite des analyses de l'etendue de la variance et des regressions quadratiques binaires. De plus, le traitement affectait aussi le contenu en malonaldehyde et l'activite de la superoxyde dismutase et de la peroxydase. La pregermination biologique a l'aide d'une RFCP combinee a une autre approche de germination physiologique pourrait etre exploitee comme technique prometteuse permettant de remedier au vieillissement des semences. Qui plus est, et de maniere imprevue, il s'averait que le traitement de vieillissement artificiel approprie pouvait liberer les semences de la dormance. [Traduit par la Redaction] Mots-cles : rhizobacteries favorisant la croissance des plantes (RFCP), germination physiologique des semences, brome cathartique, vieillissement des semences, enzymes antioxydantes., Introduction Seed ageing is an unavoidable and irreversible process that occurs in the soil seed bank or during storage, eventually resulting in a reduction in germinability and vigour, and sometimes [...]

By using SU‐8010 thermal field scanning electron microscope, JEM‐2100 transmission electron microscope, MHRS‐150 Rockwell hardness tester and X‐ray diffractometer to observe the microstructure and detect residual stress, and the measurement of the hardness and the tensile properties, the effect of stabilization treatment on the microstructure, size change, and mechanical properties of the austempered M50 steel is studied. Results show that the residue of austenite and the carbides precipitated during the bainite transformation after austempering lead to lattice shrinkage, which reduces the size of the bearing ring. The release of quenching stress after tempering increases the size. During austempering and tempering, the size fluctuates between −0.29 and 0.23 mm. After the bearing ring is stabilized for 3 times, the precipitation of filamentous carbides reaches the maximum, and the number of carbides does not increase obviously after 5 times of stabilization. The size fluctuation range is −0.9 to 0.7 μm. After M50 steel is stabilized, the transformation of residual austenite to martensite and the precipitation of carbides increase the hardness, and the coarsening of carbides reduces the ductility. The tensile strength increases from 2550 to 2650 MPa, which is related to the dispersion strengthening of carbides and their pinning effect on dislocations. [ABSTRACT FROM AUTHOR]