Synthesis, structures and properties of alkaline earth metal benzene-1,4-dioxylacetates with three-dimensional hybrid networks

Three novel alkaline earth metal benzene-1,4-dioxylacetates M(L)H₂O (M = Ca, Sr or Ba, L = benzene-1,4-dioxylacetate) with three-dimensional (3D) hybrid frameworks were reported. Both Ca(L)H₂O (1) and Sr(L)H₂O (2) crystallize in the monoclinic space group P2₁/c while Ba(L)H₂O (3) in the monoclinic space group P2₁. As determined by X-ray single-crystal analysis, in these compounds each metal ion is coordinated by eight O atoms: four from different carboxylate groups, two from one carboxylate group, one from the ether oxygen and one from one water molecule. Each L²⁻ ligand coordinates to five alkaline earth metal centers through one of its ether oxygen atoms and two carboxylate groups adopting novel μ₃-η²:η²-bridging and μ₂-η¹:η¹-bridging coordination modes to give rise to a 3D network. The luminescence analysis shows that complexes 1 and 2 exhibit fluorescence in the solid state at room temperature.     

Genetic Variation in Three Endangered Species of Encholirium (Bromeliaceae) from Cadeia do Espinhaço, Brazil, Setected using RAPD Markers

Encholirium is a Brazilian genus of Bromeliaceae that occurs exclusively in rocky landscapes. This work aimed to generate basic information for the conservation of three Encholirium species that are endemic to the rocky mountains of Cadeia do Espinhaço, employing population genetic analyses. E. pedicellatum and E. biflorum have only one very small population each, both occurring in unprotected, private land sites, being critically endangered. E. subsecundum is more widespread, and some of its populations dwell in protected areas. Five Random Amplified Polymorphic DNA (RAPD) primers generated approximately 60 polymorphic bands for each species. This technique demonstrated the presence of a single RAPD profile for every individual sampled (except for one clone found in E. biflorum). High levels of genetic variability were not expected, due to the clonal habit of the plants and small size of the populations. Populations of E. biflorum and E. pedicellatum presented, respectively, 16.06% (Φ _st  = 0.16, p<0.001) and 8.44% (Φ _st  = 0.08, p<0.001) of the total genetic diversity attributable to genetic differences among groups within the populations. In E. subsecundum, 14.52% (Φ _st  = 0.15, p<0.001) of the total genetic diversity was found among populations. Estimates of the Shannon’s Diversity Index provided similar results. These results are valuable for the development of conservation strategies.     

Mapping first to final uses for rare earth elements,globally and in the United States

Estimating the material flows of rare earth elements (REEs) is essential to understanding which industries are most vulnerable to potential REE supply disruptions which, in turn, may inform policy recommendations aimed at reducing the supply risk. However, the REEs are a group of mineral commodities characterized by highly uncertain estimates of supply and demand due to the REE market's complexity, opacity, and small size. In this study, a streamlined methodology was applied to map mineral commodity first-use to final-use applications and to estimate total requirements at the national level based on available industrial data for final-use finished goods. This analysis examines REEs both as a group and individually, showing that total US requirements are between 15% and 16.5% of world requirements for the year 2015, the latest year with the most complete information available. The findings shed light on US industrial capabilities by revealing the discrepancy between the types of REEs that go into US raw material consumption and those that are contained in embedded consumption. For instance, given the United States’ large oil refining industry, US raw material consumption of lanthanum is quite high. In contrast, US raw material consumption of neodymium is relatively low, whereas embedded demand is comparatively high. This reflects the lack of industrial capacity to process REE concentrates into magnet material combined with the US's high imports of products that contain rare earth permanent magnets.     

Rare earth and yttrium elements (REY) patterns of mesostructures of Miaolingian (Cambrian) thrombolites at Jiulongshan,Shandong Province,China

The relationship between the thrombolitic mesostructures and their depositional environments is still poorly understood due to inconsistent results by sedimentary investigation. Rare earth elements plus yttrium (REY) in ancient microbialites have been extensively applied to paleoenvironmental studies owing to their fractionation in different depositional environments. In order to investigate the environmental controls on thrombolitic mesostructures, we present the REY concentrations and patterns of four types of mesostructures of the Miaolingian (Cambrian) thrombolites in the Changhia Formation at the Jiulongshan section, Shandong Province, China. The REY compositions of those thrombolites show two distinctive groups: (1) light REY depleted patterns with negative Ce anomalies in spotted (SM) and layered mesostructures (LM) of thrombolites; and (2) flat patterns with weak Ce anomalies in dendritic (DM) and meshed mesostructures (MM) of thrombolites. Controlling factors analysis reveals that terrigenous detritus inputs have stronger influence on REY in SM and LM. In contrast, early diagenetic porewaters from underlying sediments have more serious impacts on REY concentrations and patterns in DM and MM. Our results clearly indicate that SM and LM were formed under oxic marine settings with minor terrigenous inputs, whereas DM and MM formed under suboxic marine settings suffered from early diagenetic porewater from underlying sediments. This new geochemical evidence suggests that thrombolitic mesostructures were strongly influenced by paleoenvironment, and REY of thrombolites with controlling factors analysis can be utilized as effective proxies for paleoenvironments.     

The mitogenome of Halotydeus destructor (Tucker) and its relationships with other trombidiform mites as inferred from nucleotide sequences and gene arrangements

The redlegged earth mite, Halotydeus destructor (Tucker, 1925: Trombidiformes, Eupodoidea, Penthaleidae), is an invasive mite species. In Australia, this mite has become a pest of winter pastures and grain crops. We report the complete mitogenome for H. destructor, the first to represent the family Penthaleidae, superfamily Eupodoidea. The mitogenome of H. destructor is 14,691 bp in size, and has a GC content of 27.87%, 13 protein‐coding genes, two rRNA genes, and 22 tRNA genes. We explored evolutionary relationships of H. destructor with other members of the Trombidiformes using phylogenetic analyses of nucleotide sequences and the order of protein‐coding and rRNA genes. We found strong, consistent support for the superfamily Tydeoidea being the sister taxon to the superfamily Eupodoidea based on nucleotide sequences and gene arrangements. Moreover, the gene arrangements of Eupodoidea and Tydeoidea are not only identical to each other but also identical to that of the hypothesized arthropod ancestor, showing a high level of conservatism in the mitogenomic structure of these mite superfamilies. Our study illustrates the utility of gene arrangements for providing complementary information to nucleotide sequences with respect to inferring the evolutionary relationships of species within the order Trombidiformes. The mitogenome of H. destructor provides a valuable resource for further population genetic studies of this important agricultural pest. Given the co‐occurrence of closely related, morphologically similar Penthaleidae mites with H. destructor in the field, a complete mitogenome provides new opportunities to develop metabarcoding tools to study mite diversity in agro‐ecosystems. Moreover, the H. destructor mitogenome fills an important taxonomic gap that will facilitate further study of trombidiform mite evolution.     

The Global Flow of Hard Disk Drives: Quantifying the Concept of Value Leakage in E‐waste Recovery Systems

The remaining value within end‐of‐use/life hard disk drives (EoU/L HDDs) is often not optimally recovered. The improper collection and recovery of HDDs contribute not only to rising environmental and social concerns worldwide, but also to the transformation of the economy and a significant loss of value. Currently, the most preferred treatment option for used hard drives is to recover the metals with the highest recycling effectiveness, such as steel and aluminum, via a shredding‐based recycling process that results in both value and material leakages. The complexity of retrieving the remaining values within EoU/L HDDs demands a larger view of the global supply of HDDs available for recovery. The aim of this paper is to first identify the geographical patterns of transboundary global shipments of new and used HDDs between developing and developed regions, and then capture and quantify the value leakage by bringing several unique perspectives. Two analyses have been conducted. First, the loss of value due to the insufficient recovery of neodymium (Nd) at the global level is quantified. Second, the value leakage as a result of the delay on on‐time reuse of HDDs is captured. Furthermore, the central challenges toward proper recovery of HDDs, where consumer electronic industry can make significant contributions, have been identified. HDDs are well positioned to contribute important insights to the recovery of other electronic devices, so the findings from HDDs can be adopted for other types of electronics.     

Functional relevance of synonymous alleles reflected in allele rareness in the population

We provide theoretical evidence supporting the non-neutrality of synonymous alleles by investigating the rareness of synonymous alleles in the population. We find a significantly greater number of synonymous rare alleles than conventional neutral alleles derived from noncoding regions. A permutation experiment shows that the rareness of synonymous alleles is not a byproduct of random statistical noise. We then compare the frequencies of synonymous rare alleles and common alleles in various functional contexts in which synonymous alleles are known to be involved. Subsequently, we perform logistic regression analysis to elucidate the effect size of each independent factor contributing to the rareness of synonymous alleles. Additionally, we show that changes in optimality caused by synonymous mutations resulting in rare SNPs in the population tend to be biased toward optimality loss. We think that our study will contribute to the development of novel strategies for identifying functional synonymous mutations.     

类卟啉稀土配合物对于小鼠腹水肝癌细胞光敏损伤的研究

研究了类卟啉稀土配合物（以下简称ＰＬＭ—Ｇｄ—Ａ）对小鼠腹水肝癌细胞（ＡＨ）的光敏作用及ＡＨ细胞对ＰＬＭ一Ｇｄ—Ａ的摄取表明：ＰＬＭ－Ｇｄ－Ａ被ＡＨ细胞摄取的速度快（大约１０ｍｉｎ可达到平衡）,用ＭＴＴ方法测定了细胞光敏存活曲线,杀伤细胞的能力与光照时间和光照强度以及ＰＬＭ—Ｇｄ的浓度密切相关,用ＦＡＤＵ方法和电镜观察结果证明：该光敏损伤细胞的靶主要是在细胞核;对于不同稀土离子配合物光敏能力比较表明：Ｇｄ＞Ｅｕ＞Ｓｍ;造成细胞死亡的原因包括１Ｏ２、在内的活性氧。