Oxalate Oxidase Model Studies – Substrate Reactivity

The synthesis and structure of [MnLCl]0.5H2O (1·0.5H2O, HL = 1‐benzyl‐4‐acetato‐1,4,7‐triazacyclononane) is reported. Complex 1 exists as a coordination polymer in the solid state, and the MnII center is bonded to three amine nitrogen atoms, one carboxylate oxygen atom, a chlorido ligand, and an adjacent carboxylate group in a chelating fashion to afford a seven‐coordinate center. The dissolution of 1 in acetonitrile containing excess oxalate (ox) ions results in a monomeric species. When mixtures of 1 and oxalate ions are exposed to oxygen under ambient conditions, a dark pink EPR‐silent species is generated. The pink species is believed to be [MnIII(ox)2]–, which results from the displacement of the ligand L– by an oxalate ion. The decomposition of this species ultimately results in the formation of 1 equiv. of CO2 per oxalate ion consumed, a HCO3– ion, and a MnII species. Further reaction of the resulting MnII species with excess oxalate in the presence of oxygen leads to additional oxalate degradation.MnLCl (HL = 1‐benzyl‐4‐acetato‐1,4,7‐triazacyclononane) is investigated as a structural and functional model for oxalate oxidase. MnLCl effects the catalytic degradation of oxalate ions under ambient conditions. MnLCl is converted to a light‐sensitive intermediate during catalysis. Analysis of the reaction mixture indicates that 1 equiv. of CO2 per oxalate ion is produced along with a HCO3– ion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110613/1/646_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110613/2/ejic_201402835_sm_miscellaneous_information.pd

Phenotypic Switching of Nonpeptidergic Cutaneous Sensory Neurons following Peripheral Nerve Injury

In adult mammals, the phenotype of half of all pain-sensing (nociceptive) sensory neurons is tonically modulated by growth factors in the glial cell line-derived neurotrophic factor (GDNF) family that includes GDNF, artemin (ARTN) and neurturin (NRTN). Each family member binds a distinct GFRα family co-receptor, such that GDNF, NRTN and ARTN bind GFRα1, -α2, and -α3, respectively. Previous studies revealed transcriptional regulation of all three receptors in following axotomy, possibly in response to changes in growth factor availability. Here, we examined changes in the expression of GFRα1-3 in response to injury in vivo and in vitro. We found that after dissociation of adult sensory ganglia, up to 27% of neurons die within 4 days (d) in culture and this can be prevented by nerve growth factor (NGF), GDNF and ARTN, but not NRTN. Moreover, up-regulation of ATF3 (a marker of neuronal injury) in vitro could be prevented by NGF and ARTN, but not by GDNF or NRTN. The lack of NRTN efficacy was correlated with rapid and near-complete loss of GFRα2 immunoreactivity. By retrogradely-labeling cutaneous afferents in vivo prior to nerve cut, we demonstrated that GFRα2-positive neurons switch phenotype following injury and begin to express GFRα3 as well as the capsaicin receptor, transient receptor potential vanilloid 1(TRPV1), an important transducer of noxious stimuli. This switch was correlated with down-regulation of Runt-related transcription factor 1 (Runx1), a transcription factor that controls expression of GFRα2 and TRPV1 during development. These studies show that NRTN-responsive neurons are unique with respect to their plasticity and response to injury, and suggest that Runx1 plays an ongoing modulatory role in the adult

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

The Role of Water in Lanthanide-Catalyzed Carbon–Carbon Bond Formation

molecule

Synthesis, Spectroscopic Characterization, and Reactivity of Water-Tolerant Eu³⁺-Based Precatalysts

We report the synthesis, spectroscopic characterization, and reactivity of Eu³⁺ in the presence of a new set of chiral ligands designed for the aqueous, enantioselective Mukaiyama aldol reaction. Luminescence and NMR measurements were used to characterize the coordination environments of the Eu³⁺-based precatalysts, and this data is compared with yields and stereoselectivities. In addition to structure–function relationships, we found that, in the presence of excess hexadentate ligands, Eu³⁺ is coordinatively saturated, and subsequently, the reactivity of the precatalysts is reduced. These findings are helpful for the design of new ligands that bind Eu³⁺ without saturating the Eu³⁺ coordination sphere

Study of the Lanthanide-Catalyzed, Aqueous, Asymmetric Mukaiyama Aldol Reaction

The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lanthanide ions, and an exploration of substrate scope that includes aromatic and aliphatic aldehydes and silyl enol ethers derived from aromatic and aliphatic ketones

Measures of self-efficacy and optimism in older adults with generalized anxiety

This study provides initial psychometric data for the Self-Efficacy Scale (SES) and the Life Orientation Test (LOT) in a sample of older adults with generalized anxiety disorder (GAD). Participants included 76 adults, ages 60 to 80, who met Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for GAD. Self-efficacy and outcome expectancies were lower in older adults with GAD relative to published data from younger and older community samples. Both the SES and LOT demonstrated adequate internal consistency. Confirmatory factor analysis provided evidence for optimism and pessimism factors within the LOT, and exploratory factor analysis of the SES suggested three factors that overlap with previous findings. Overall, the data support the potential utility of these instruments in late-life GAD and set the stage for future investigations of generalized self-efficacy expectancies and outcome expectancies (or optimism) as they relate to the prediction of affect and behavior in this group

\u27Minor GAD\u27: Characteristics of subsyndromal GAD in older adults

Subsyndromal emotional symptoms are common in older adults and are associated with increased disability, health care utilization, and risk for developing psychiatric disorders. The purpose of this study was to examine subsyndromal generalized anxiety disorder (GAD) in older adults. Participants included 30 older adults with diagnosable GAD, 19 with subsyndromal anxiety symptoms [minor GAD; (MGAD)], and 21 normal control volunteers (NC). Participants were assessed using the Anxiety Disorders Interview Schedule for DSM-IV and completed self-report measures of anxiety, worry, depression, and life satisfaction. Excessive worry on more days than not, difficulty controlling worry, and clinically significant distress or impairment were the diagnostic criteria endorsed by MGAD participants least often. Therefore, these criteria may be useful in distinguishing between GAD and subsyndromal GAD. Self-reported anxiety and worry also systematically differed across groups in the expected directions, with a discriminant analysis yielding good classification of the GAD and NC groups based on these measures. Categorization of MGAD participants generally was poor, with most misclassified as GAD patients. Clinical implications of these findings are discussed. © 2003 Elsevier Science Ltd. All rights reserved