Rock weathering is crucial in the development of soil. Yet the role of bacteria in the fine particle-forming process of purple mudstone is not fully understood, especially under nitrogen fertilization.In this study, the particles (0.25 mm to 1 mm) of purple mudstone from Penglai Group (J3p) were selected as the test material. Two nitrogen fertilizers, i.e., urea (U) and ammonium bicarbonate (AB), and four application levels (0, 280, 560, and 840 N kg∙ha-1) with 18 replications were designed in an incubation experiment. The weathering indices and bacterial community structure of the purple mudstone particles were investigated after 120 days of incubation.The results showed that the weathering indices of purple mudstone particles in the AB treatment were higher than that in the U treatment at the same fertilization levels and a reducing trend was observed with increasing nitrogen fertilizer levels under the same nitrogen fertilizer application types. The diversities of the bacterial community were extremely significantly altered by nitrogen fertilizer application (p < 0.01). The effect of the nitrogen fertilizer application level on the beta diversity of the bacterial community (R2 = 0.34) was greater than that of the nitrogen fertilizer application type (R2 = 0.20). Through stepwise regression analysis, the positive effects of nitrification of Nitrobacter (Nitrolancea) (R2 = 0.36), the Phosphorous-dissolving bacteria (Massilia) (R2 = 0.12), and N-NO3- (R2 = 0.35) on the weathering indices of J3p purple mudstone particles could be observed. Structural equation modelling indicated that nitrogen fertilizer application level affects the abundance of the dominant species at the genus level (Nitrolancea and Massilia), and key environmental factor (N-NO3-), which in turn accelerated the weathering indices (59%).Our findings imply that the enhancements of nitrification of Nitrobacter (Nitrolancea) and of phosphorus solubilization of Phosphorous-dissolving bacteria (Massilia) by nitrogen fertilization are the key factors affecting the weathering indices of J3p purple mudstone particles.
Multiple studies have confirmed that acid sphingomyelinase (ASM) activity is associated with depression. The discovery of direct inhibitors against ASM is of great significance for exploring antidepressants and their mechanisms of action. Herein, a series of novel phenylpyrazole analogues were rationally designed and synthesized. Among them, compound
Single event effect (SEE) and space electrostatic discharge (SESD) are two important types of effects causing spacecraft anomalies. However, it is difficult to differentiate them to identify the root cause of on-orbit anomalies. This paper pioneers the comparative study of the “soft errors” induced by the SEE and SESD with a well-known static random-access memory (SRAM). The similarity and difference of the physical mechanisms between the “soft errors” induced by SEE and SESD are studied with the technology computer-aided design (TCAD) simulations. Meanwhile, the characteristics of the “soft errors” and the relation with external stimulus between SEE and SESD are further investigated with the pulsed laser SEE facility and SESD test system. The results showed that the similar appearances of “soft errors” can be generated by both SEE and SESD, while multiple-bit upset (MBU) has been observed only in SESD testing. In addition, in comparison to the random distribution of SEE sensitivity areas, the SESD sensitivity areas are in closer proximity to the power supply regions. The different symptoms in upsets can be used to identify the root causes of the spacecraft anomalies.
DNA-encoded library technology (DELT) facilitates the generation of billions of DNA-tagged macrocycles containing noncanonical amino acids, synthesized through diverse cyclization strategies. The varied appended residues and ring conformations expand chemical space, enabling the identification of hit compounds with improved properties such as higher binding affinity, enhanced metabolic stability, and increased oral bioavailability. This study expands the on-DNA chemical toolkit by introducing a DNA-compatible C(sp3)-C(sp3) bond formation method via a visible-light-mediated desulfurative macrocyclization. This reaction proceeds efficiently under mild conditions, exhibiting broad substrate scope and good conversions. Notably, the reaction condition is com-patible with free amines, allowing for late-stage modifications and the preparation of covalent DNA-encoded macrocyclic libraries.
Herein, two new or overlooked features of ZIF-90 were identified and investigated. Imidazole-2-carboxaldehyde is fluorescent, but its fluorescence in ZIF-90 is quenched by an ACQ effect. ZIF-90 can enhance the fluorescence of Cy5, but quench that of 6-FAM. The applicability of the two newly identified features in biosensing was explored.
Correction for 'Substrate specificity of FUT8 and chemoenzymatic synthesis of core-fucosylated asymmetric N-glycans' by Angie D. Calderon et al., Org. Biomol. Chem., 2016, DOI: 10.1039/c6ob00586a.
The assessment of soil health through a robust index system having a sufficient number of indicators is an important step toward sustainable crop production. The present study aimed at establishing a minimum data set (MDS) from soil functional and nutritional attributes using a dual index system to evaluate the soil health of farmlands under wheat (Triticum aestivum)–maize (Zea mays) crop rotation in Yanting County, Sichuan, China. Farms from 10 villages in the study area were selected, out of which three sites were considered healthy/ideal sites and used as a reference for the remaining seven targeted sites, and soil samples were collected at depth of 20 cm from these farms. The MDS indicators were selected by using principal component analysis (PCA) followed by Pearson’s correlation on 25 attributes. Based on significant values, eight attributes were retained in the final MDS, including the sucrase level, pH, wilting coefficient, water holding capacity, organic matter, NK ratio, total potassium, and available phosphorus. Based on the results, most of the farmland soils in Yanting County were in a healthy condition, accounting for 61.71% of the surveyed samples, followed by sub-healthy, degraded, and weak soils, accounting for 19.64%, 9.71%, and 8.93%, respectively. The values of most of the indicators at the targeted sites were significantly lower than those at ideal sites. Thus, specific steps should be taken by adding soil organic matter, combined with other fertilizers, to enhance the microbial biomass, enzymatic activities, and other biological activities in the soil.
Transcriptome-based computational drug repurposing has attracted considerable interest by bringing about faster and more cost-effective drug discovery. Nevertheless, key limitations of the current drug connectivity-mapping paradigm have been long overlooked, including the lack of effective means to determine optimal query gene signatures.The novel approach Dr Insight implements a frame-breaking statistical model for the 'hand-shake' between disease and drug data. The genome-wide screening of concordantly expressed genes (CEGs) eliminates the need for subjective selection of query signatures, added to eliciting better proxy for potential disease-specific drug targets. Extensive comparisons on simulated and real cancer datasets have validated the superior performance of Dr Insight over several popular drug-repurposing methods to detect known cancer drugs and drug-target interactions. A proof-of-concept trial using the TCGA breast cancer dataset demonstrates the application of Dr Insight for a comprehensive analysis, from redirection of drug therapies, to a systematic construction of disease-specific drug-target networks.Dr Insight R package is available at https://cran.r-project.org/web/packages/DrInsight/index.html.Supplementary data are available at Bioinformatics online.
As discovered by the previous selection outcomes, we developed a Rhodium-promoted C-H activation/ annulation reaction of DNA-linked terminal alkyne and aromatic acid. This reaction exhibits excellent efficiency with high conversions and a wide broad sub-strate scope. Most importantly, the unique DEL-compatible condition provides a better scenario to yield an isocoumarin scaffold compared to conventional organic reaction condition, and this newly developed on-DNA method has confirmed its feasibility in preparing DNA-encoded libraries.
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