Summary
We systematically reviewed the safety and efficacy of perineural dexamethasone as an adjunct for peripheral nerve blockade in 29 controlled trials of 1695 participants. We grouped trials by ...the duration of local anaesthetic action (short‐ or medium‐ vs long‐term). Dexamethasone increased the mean (95% CI) duration of analgesia by 233 (172–295) min when injected with short‐ or medium‐term action local anaesthetics and by 488 (419–557) min when injected with long‐term action local anaesthetics, p < 0.00001 for both. However, these results should be interpreted with caution due to the extreme heterogeneity of results, with I2 exceeding 90% for both analyses. Meta‐regression did not show an interaction between dose of perineural dexamethasone (4–10 mg) and duration of analgesia (r2 = 0.02, p = 0.54). There were no differences between 4 and 8 mg dexamethasone on subgroup analysis.
A new approach to fused helicenes is reported, where varied substituents are readily incorporated in the extended aromatic frame. From the alkynyl precursor, the final helical compounds are obtained ...under mild conditions in a two‐step process, in which the final C−C bond is formed via a photochemical cyclization/ dehydroiodination sequence. The distortion of the π‐system from planarity leads to unusual packing in the solid state. Computational analysis reveals that substituent incorporation perturbs geometries and electronic structures of these nonplanar aromatics.
A new approach to fused helicenes is reported, in which varied substituents are readily incorporated in the extended aromatic frame. From an alkynyl precursor, the final helical compounds are obtained in a two‐step process, in which the final C−C bond is photochemically forged by coupling cyclization and dehydroiodination. The distortion of the π‐system from planarity leads to unusual packing in the solid state.
Maize is both an exciting model organism in plant genetics and also the most important crop worldwide for food, animal feed and bioenergy production. Recent genome-wide association and metabolic ...profiling studies aimed to resolve quantitative traits to their causal genetic loci and key metabolic regulators. Here we present a complementary approach that exploits large-scale genomic and metabolic information to predict complex, highly polygenic traits in hybrid testcrosses. We crossed 285 diverse Dent inbred lines from worldwide sources with two testers and predicted their combining abilities for seven biomass- and bioenergy-related traits using 56,110 SNPs and 130 metabolites. Whole-genome and metabolic prediction models were built by fitting effects for all SNPs or metabolites. Prediction accuracies ranged from 0.72 to 0.81 for SNPs and from 0.60 to 0.80 for metabolites, allowing a reliable screening of large collections of diverse inbred lines for their potential to create superior hybrids.
Metal-organic frameworks (MOFs) based on zirconium phosphonates exhibit superior chemical stability suitable for applications under harsh conditions. These compounds mostly exist as poorly ...crystallized precipitates, and precise structural information has therefore remained elusive. Furthermore, a zero-dimensional zirconium phosphonate cluster acting as secondary building unit has been lacking, leading to poor designability in this system. Herein, we overcome these challenges and obtain single crystals of three zirconium phosphonates that are suitable for structural analysis. These compounds are built by previously unknown isolated zirconium phosphonate clusters and exhibit combined high porosity and ultrastability even in fuming acids. SZ-2 possesses the largest void volume recorded in zirconium phosphonates and SZ-3 represents the most porous crystalline zirconium phosphonate and the only porous MOF material reported to survive in aqua regia. SZ-2 and SZ-3 can effectively remove uranyl ions from aqueous solutions over a wide pH range, and we have elucidated the removal mechanism.
Covalency is often considered to be an influential factor in driving An3+ vs. Ln3+ selectivity invoked by soft donor ligands. This is intensely debated, particularly the extent to which An3+/Ln3+ ...covalency differences prevail and manifest as the f‐block is traversed, and the effects of periodic breaks beyond Pu. Herein, two Am complexes, Am{N(E=PPh2)2}3 (1‐Am, E=Se; 2‐Am, E=O) are compared to isoradial Nd{N(E=PPh2)2}3 (1‐Nd, 2‐Nd) complexes. Covalent contributions are assessed and compared to U/La and Pu/Ce analogues. Through ab initio calculations grounded in UV‐vis‐NIR spectroscopy and single‐crystal X‐ray structures, we observe differences in f orbital involvement between Am–Se and Nd–Se bonds, which are not present in O‐donor congeners.
Two Am complexes, Am{N(E=PPh2)2}3 (1‐Am, E=Se; 2‐Am, E=O) are compared to isoradial Nd{N(E=PPh2)2}3 (1‐Nd, 2‐Nd) complexes. Covalent contributions are assessed and compared to U/La and Pu/Ce analogues. Through ab initio calculations grounded in UV‐vis‐NIR spectroscopy and single‐crystal X‐ray structures, we observe differences in f‐orbital involvement between Am–Se and Nd–Se bonds, which are not present in O‐donor congeners.
Many environmental pollutants inherently exist in their anionic forms and are therefore highly mobile in natural water systems. Cationic framework materials that can capture those pollutants are ...highly desirable but scarcely reported. Here we present a mesoporous cationic thorium-based MOF (SCU-8) containing channels with a large inner diameter of 2.2 nm and possessing a high surface area of 1360 m
g
. The anion-exchange properties of SCU-8 were explored with many anions including small oxo anions like ReO
and Cr
O
as well as anionic organic dyes like methyl blue and the persistent organic pollutant, perfluorooctane sulfonate (PFOS). Both fast uptake kinetics and great sorption selectivity toward PFOS are observed. The underlying sorption mechanism was probed using quantum mechanical and molecular dynamics simulations. These computational results reveal that PFOS anions are immobilized in SCU-8 by driving forces including electrostatic interactions, hydrogen bonds, hydrophobic interactions, and van der Waals interactions at different adsorption stages.
Summary
Moderate‐to‐severe postoperative pain persists for longer than the duration of single‐shot peripheral nerve blocks and hence continues to be a problem even with the routine use of regional ...anaesthesia techniques. The administration of local anaesthetic adjuncts, defined as the concomitant intravenous or perineural injection of one or more pharmacological agents, is an attractive and technically simple strategy to potentially extend the benefits of peripheral nerve blockade beyond the conventional maximum of 8–14 hours. Historical local anaesthetic adjuncts include perineural adrenaline that has been demonstrated to increase the mean duration of analgesia by as little as just over 1 hour. Of the novel local anaesthetic adjuncts, dexmedetomidine and dexamethasone have best demonstrated the capacity to considerably improve the duration of blocks. Perineural dexmedetomidine and dexamethasone increase the mean duration of analgesia by up to 6 hour and 8 hour, respectively, when combined with long‐acting local anaesthetics. The evidence for the safety of these local anaesthetic adjuncts continues to accumulate, although the findings of a neurotoxic effect with perineural dexmedetomidine during in‐vitro studies are conflicting. Neither perineural dexmedetomidine nor dexamethasone fulfils all the criteria of the ideal local anaesthetic adjunct. Dexmedetomidine is limited by side‐effects such as bradycardia, hypotension and sedation, and dexamethasone slightly increases glycaemia. In view of the concerns related to localised nerve and muscle injury and the lack of consistent evidence for the superiority of the perineural vs. systemic route of administration, we recommend the off‐label use of systemic dexamethasone as a local anaesthetic adjunct in a dose of 0.1–0.2 mg.kg−1 for all patients undergoing surgery associated with significant postoperative pain.
The merging of small‐scale syntheses and rapid crystallization methods have provided access to crystalline samples of berkelium (Z=97) and californium (Z=98) coordination complexes and compounds that ...can be interrogated with a suite of spectroscopic tools and structural elucidation approaches that have come online over the last 20 years. The combination of this experimental data with relativistic theoretical methods that capture the effects of spin‐orbit coupling and scalar relativistic effects have allowed us to understand the electronic structure of berkelium and californium compounds at a level of detail that was not previously possible. The harbinger of this new era of post‐curium chemistry was the synthesis and characterization of Cf{B6O8(OH)5}. This compound possesses a structure type that is distinct from earlier actinide borates, a reduction in coordination number for californium, contracted Cf−O bond lengths, a substantially reduced magnetic moment with respect to the calculated free‐ion moment and, most importantly, vibronically coupled broadband photoluminescence. Ligand‐field analysis also showed that the splitting of the ground state was larger than typically found in the f‐block elements, and when taken together places its overall electronic structure as a hybrid of d‐ and f‐block components. The discovery of the unusual properties of this compound has led to the development of large families of 4f and 5f coordination complexes, in an effort to uncover the underlying origin of the electronic structure oddities, and whether there really is a sharp onset of these changes at californium. This in turn pushed the development of far more challenging berkelium chemistry (from a radiologic standpoint) because the half‐life of the isotopes decreases from 351 years for 249Cf to 330 days for 249Bk. This short review details some of the chemistry that has been reported over the last 15 years, and its consequences for understanding the periodic table.
The difference between being early or late is important! Recent investigations of berkelium and californium demonstrates why the later actinides deserve special treatment and should no longer be viewed as “lanthanide‐like”.
The diversity of metabolites found in plants is by far greater than in most other organisms. Metabolic profiling techniques, which measure many of these compounds simultaneously, enabled ...investigating the regulation of metabolic networks and proved to be useful for predicting important agronomic traits. However, little is known about the genetic basis of metabolites in crops such as maize. Here, a set of 289 diverse maize inbred lines was genotyped with 56,110 SNPs and assayed for 118 biochemical compounds in the leaves of young plants, as well as for agronomic traits of mature plants in field trials. Metabolite concentrations had on average a repeatability of 0.73 and showed a correlation pattern that largely reflected their functional grouping. Genome-wide association mapping with correction for population structure and cryptic relatedness identified for 26 distinct metabolites strong associations with SNPs, explaining up to 32.0% of the observed genetic variance. On nine chromosomes, we detected 15 distinct SNP-metabolite associations, each of which explained more then 15% of the genetic variance. For lignin precursors, including p-coumaric acid and caffeic acid, we found strong associations (P values 2.7 × 10⁻¹⁰ to 3.9 × 10⁻¹⁸) with a region on chromosome 9 harboring cinnamoyl-CoA reductase, a key enzyme in monolignol synthesis and a target for improving the quality of lignocellulosic biomass by genetic engineering approaches. Moreover, lignin precursors correlated significantly with lignin content, plant height, and dry matter yield, suggesting that metabolites represent promising connecting links for narrowing the genotypephenotype gap of complex agronomic traits.
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