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In this paper, glasshouse experiments were conducted to determine the accumulation, distribution and transformation of DDTs and HCHs by maize under pot culture conditions. The culture soil was spiked with the organic pollutants and samples were collected in different durations. Analysis of the plants at harvest showed that the selected plant varied widely in their ability to remove and translocate DDTs and HCHs from the soil, the bioconcentration factor ranged from 0.004 to 0.027 for the shoot and from 0.036 to 0.097 for the roots, and the translocation factors were lower than 0.1 with variation between DDTs and HCHs, but no significant differences were observed. DDTs appeared to have accumulated by both passive adsorption and active absorption, p,p'-DDT and p,p'-DDE were the major metabolite and the transformation was mediated by reductive dehalogenation, the affinity of the OCPs for lipids is one of the major factors affecting their uptake and translocation within the plants. [ABSTRACT FROM AUTHOR]

Recognition of remote homologous structures is a necessary module in AlphaFold2 and is also essential for the exploration of protein folding pathways. Here, we propose a method, PAthreader, to recognize remote templates and explore folding pathways. Firstly, we design a three-track alignment between predicted distance profiles and structure profiles extracted from PDB and AlphaFold DB, to improve the recognition accuracy of remote templates. Secondly, we improve the performance of AlphaFold2 using the templates identified by PAthreader. Thirdly, we explore protein folding pathways based on our conjecture that dynamic folding information of protein is implicitly contained in its remote homologs. The results show that the average accuracy of PAthreader templates is 11.6% higher than that of HHsearch. In terms of structure modelling, PAthreader outperform AlphaFold2 and ranks first on the CAMEO blind test for the latest three months. Furthermore, we predict protein folding pathways for 37 proteins, in which the results of 7 proteins are almost consistent with those of biological experiments, and the other 30 human proteins have yet to be verified by biological experiments, revealing that folding information can be exploited from remote homologous structures. PAthreader generates templates of remote homologous structures to improve protein structure prediction by AlphaFold2 and predict folding pathways under the hypothesis that folding information is evolutionarily conserved in remote homologs. [ABSTRACT FROM AUTHOR]

A quadrupolar compound Pyr‐BA with two pyrrole‐type nitrogen atoms doped externally was prepared in this work. In high contrast with other π ionic radicals, its cationic radical Pyr‐BA⋅+ undergoes unusual symmetry‐broken charge separation (SB‐CS), generating the mixed valence complex of Pyr‐BA+1−q⋅⋅⋅Pyr‐BA+1+q, where q is the degree of charge transfer. Variable‐temperature (VT) single‐crystal analysis, absorption and EPR experiments all confirmed that aggregation and lower temperature would help to facilitate this SB‐CS process. Gibbs energy calculations and gauge‐including magnetically induced current simulation both validate that, for Pyr‐BA⋅+, SB‐CS behavior is more favorable than the conventional dimerization mode. To the best of our knowledge, this is the first study that shows solid single‐crystal evidence for spontaneous SB‐CS between identical ionic radicals. Such a unique phenomenon is of great significance both in terms of fundamental aspects and uncharted material science. [ABSTRACT FROM AUTHOR]

A quadrupolar compound Pyr‐BA with two pyrrole‐type nitrogen atoms doped externally was prepared in this work. In high contrast with other π ionic radicals, its cationic radical Pyr‐BA⋅+ undergoes unusual symmetry‐broken charge separation (SB‐CS), generating the mixed valence complex of Pyr‐BA+1−q⋅⋅⋅Pyr‐BA+1+q, where q is the degree of charge transfer. Variable‐temperature (VT) single‐crystal analysis, absorption and EPR experiments all confirmed that aggregation and lower temperature would help to facilitate this SB‐CS process. Gibbs energy calculations and gauge‐including magnetically induced current simulation both validate that, for Pyr‐BA⋅+, SB‐CS behavior is more favorable than the conventional dimerization mode. To the best of our knowledge, this is the first study that shows solid single‐crystal evidence for spontaneous SB‐CS between identical ionic radicals. Such a unique phenomenon is of great significance both in terms of fundamental aspects and uncharted material science. [ABSTRACT FROM AUTHOR]

As an important source, sink and pool of carbon, lake sediment plays an important role in carbon cycle. Inorganic carbon (IC) in lake sediment is abundant, however the role of inorganic carbon in lake systems in terrestrial carbon cycling remains less clear. In this paper, the spatial variations, source and transformation of IC in sediments of Lake Hulun were investigated and compared with typical lakes of Inner Mongolia Plateau by analyzing the influencing factors. The results showed that contents of total IC in surface sediment in Lake Hulun ranged from 17.2 to 66.7 mg g–1 with a mean of 42.6 mg g–1, and the pattern of spatial distribution showed obviously decreasing trend from southwest to northeast lake districts. The order size of IC fractions in surface sediment was in a sequence of EX (extracted by NaCl) < SAL (extracted by NaOH) < WAL (extracted by NH3·H2O) ⪡ SAC (extracted by HCl) < WAC (extracted by HO-NH2·HCl), the WAC and SAC fractions were the major fractions, accounted for 80% of total IC. In vertical distribution, the WAC and SAC fractions presented obviously opposite spatial distribution, indicted that these fractions could transform into each other in sediments. The ratio of IAP/Ksp in lake water ranged from 8.87 to 108.5, suggested that this lake had what it took to form the authigenic carbonate precipitation. A differential analysis study indicated that the mechanisms what made the difference of IC content in four lakes were multiple, the chemical properties and temperature of lake water, the defusion or dissolve of CO2, biomass and sediment environment were the key factors that might affect the contents of inorganic carbon in the lake sediment. [ABSTRACT FROM AUTHOR]