Intermolecular C-H activation with an Ir-METAMORPhos piano-stool complex: multiple reaction steps at a reactive ligand

Substrate activation by means of a reactive ligand is a topic of much interest. Herein we describe a stoichiometric anti-Markovnikov C-N bond formation involving ligand reactivity in multiple steps along the reaction coordinate, including ligand assisted substrate (de)protonation and C-N bond formation, as illustrated by a combined experimental, spectroscopic and computational study. This affords a highly unusual four-membered iridacycle bearing an exo-cyclic C=C double bond

General practitioners' prescribing behaviour as a determinant of poor persistence with inhaled corticosteroids in children with respiratory symptoms:Mixed methods study

OBJECTIVES: To evaluate general practitioners’ (GPs’) prescribing behaviour as a determinant of persistence with and adherence to inhaled corticosteroids (ICS) in children. DESIGN: Prospective observational study of persistence with and adherence to ICS followed by a focus group study of the GPs prescribing this treatment. SETTING: 7 primary care practices in the area of Zwolle, the Netherlands. PARTICIPANTS: 134 children aged 2–12 years had been prescribed ICS in the year before the study started by their 19 GPs. MAIN OUTCOME MEASURES: Patterns and motives of GPs’ prescribing behaviour and the relationship with persistence with and adherence to ICS. RESULTS: GPs’ prescribing behaviour was characterised by prescribing short courses of ICS to children with various respiratory symptoms without follow-up for making a diagnosis of asthma. This was driven by the GPs’ pragmatic approach to deal with the large number of children with respiratory symptoms, and by beliefs about ICS which differed from currently available evidence. This prescribing behaviour was the main reason why 68 (51%) children did not persist with the use of ICS. In children with persistent use of ICS and a GP's advice to use ICS on a daily basis, the median (IQR) adherence was 70% (41–84%), and was similar for patients with persistent asthma and children lacking a diagnosis or symptoms of asthma. CONCLUSIONS: Inappropriate prescription of ICS to children by GPs is common and drives the lack of persistence with ICS therapy in primary care. This finding should be taken into account when interpreting data from large prescription database studies. Improving primary healthcare providers’ knowledge and competence in diagnosing and managing asthma in children is needed

Політичні процеси в українському суспільстві на початку ХХІ століття

У статті висвітлюються питання щодо наукового осмислення політичних процесів розвитку українського суспільства на початку ХХІ століття та ролі політичної науки у процесах його функціонування.The author reviews the problems of scientific conceptualizing of political processes of the development of Ukrainian society at the beginning of the 21-st century and the role of political science in processes of its functioning

O-GlcNAcylation of master growth repressor DELLA by SECRET AGENT modulates multiple signaling pathways in Arabidopsis

The DELLA family of transcription regulators functions as master growth repressors in plants by inhibiting phytohormone gibberellin (GA) signaling in response to developmental and environmental cues. DELLAs also play a central role in mediating cross-talk between GA and other signaling pathways via antagonistic direct interactions with key transcription factors. However, how these crucial protein–protein interactions can be dynamically regulated during plant development remains unclear. Here, we show that DELLAs are modified by the O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) SECRET AGENT (SEC) in Arabidopsis. O-GlcNAcylation of the DELLA protein REPRESSOR OF ga1-3 (RGA) inhibits RGA binding to four of its interactors—PHYTOCHROME-INTERACTING FACTOR3 (PIF3), PIF4, JASMONATE-ZIM DOMAIN1, and BRASSINAZOLE-RESISTANT1 (BZR1)—that are key regulators in light, jasmonate, and brassinosteroid signaling pathways, respectively. Consistent with this, the sec-null mutant displayed reduced responses to GA and brassinosteroid and showed decreased expression of several common target genes of DELLAs, BZR1, and PIFs. Our results reveal a direct role of OGT in repressing DELLA activity and indicate that O-GlcNAcylation of DELLAs provides a fine-tuning mechanism in coordinating multiple signaling activities during plant development

Neurobiological correlates of antisociality across adolescence and young adulthood: a multi-sample, multi-method study

Pathways through Adolescenc

Nck adapter proteins: functional versatility in T cells

Nck is a ubiquitously expressed adapter protein that is almost exclusively built of one SH2 domain and three SH3 domains. The two isoproteins of Nck are functionally redundant in many aspects and differ in only few amino acids that are mostly located in the linker regions between the interaction modules. Nck proteins connect receptor and non-receptor tyrosine kinases to the machinery of actin reorganisation. Thereby, Nck regulates activation-dependent processes during cell polarisation and migration and plays a crucial role in the signal transduction of a variety of receptors including for instance PDGF-, HGF-, VEGF- and Ephrin receptors. In most cases, the SH2 domain mediates binding to the phosphorylated receptor or associated phosphoproteins, while SH3 domain interactions lead to the formation of larger protein complexes. In T lymphocytes, Nck plays a pivotal role in the T cell receptor (TCR)-induced reorganisation of the actin cytoskeleton and the formation of the immunological synapse. However, in this context, two different mechanisms and adapter complexes are discussed. In the first scenario, dependent on an activation-induced conformational change in the CD3ε subunits, a direct binding of Nck to components of the TCR/CD3 complex was shown. In the second scenario, Nck is recruited to the TCR complex via phosphorylated Slp76, another central constituent of the membrane proximal activation complex. Over the past years, a large number of putative Nck interactors have been identified in different cellular systems that point to diverse additional functions of the adapter protein, e.g. in the control of gene expression and proliferation

Maturation of the Cardiac Autonomic Nervous System Activity in Children and Adolescents

Background Despite the increasing interest in cardiac autonomic nervous activity, the normal development is not fully understood. The main aim was to determine the maturation of different cardiac sympathetic‐(SNS) and parasympathetic nervous system (PNS) activity parameters in healthy patients aged 0.5 to 20 years. A second aim was to determine potential sex differences. Methods and Results Five studies covering the 0.5‐ to 20‐year age range provided impedance‐ and electrocardiography recordings from which heart rate, different PNS‐parameters (eg, respiratory sinus arrhythmia) and an SNS‐parameter (pre‐ejection period) were collected. Age trends were computed in the mean values across 12 age‐bins and in the age‐specific variances. Age was associated with changes in mean and variance of all parameters. PNS‐activity followed a cubic trend, with an exponential increase from infancy, a plateau phase during middle childhood, followed by a decrease to adolescence. SNS‐activity showed a more linear trend, with a gradual decrease from infancy to adolescence. Boys had higher SNS‐activity at ages 11 to 15 years, while PNS‐activity was higher at 5 and 11 to 12 years with the plateau level reached earlier in girls. Interindividual variation was high at all ages. Variance was reasonably stable for SNS‐ and the log‐transformed PNS‐parameters. Conclusions Cardiac PNS‐ and SNS‐activity in childhood follows different maturational trajectories. Whereas PNS‐activity shows a cubic trend with a plateau phase during middle childhood, SNS‐activity shows a linear decrease from 0.5 to 20 years. Despite the large samples used, clinical use of the sex‐specific centile and percentile normative values is modest in view of the large individual differences, even within narrow age bands.National Institute of Diabetes and Digestive and Kidney Diseases; the Netherlands Organization for Scientific Research; National Initiative for Brain and Cognition Research; European Commission under the 7th Framework Health Program with Grant; The Netherlands Organization for Health Research and Development (ZonMw); The Dutch Heart Foundatio

The role of METAMORPhos ligands in transition metal complex formation and catalysis

Chemists are challenged to develop homogeneous transition metal catalysts that are faster, more selective, cheaper, safer, robust and environmentally benign. This is generally approached by varying the ligands that are coordinated to the applied metal to steer its properties. Traditionally, ligands functioned merely as spectators and affected the reactivity of a metal center via their electronic donating/accepting abilities and steric properties. However the role of ligands has been broadened and they can be designed such that they are actively involved during catalysis via for instance hydrogen bonding interactions, redox non-innocence or proton responsiveness. These types of ligands are commonly called bifunctional ligands. This manuscript describes the preparation of several bifunctional (bis)METAMORPhos ligands and their coordination towards the transition metals Rh, Ir and Pd. Furthermore, the role of the ligand during complex formation and catalysis is outlined. For example, the development of several bisMETAMORPhos-iridium complexes and their application in base-free dehydrogenation of formic acid is described. The role of the ligand during catalysis is detailed based on experimental and computational results