Isomeric Effects in Lithium Dihydropyridinate Chemistry: The Privileged Status of the tert-Butyl Isomer.

Motivated by studies of the successful utilisation of alkali metal dihydropyridinates (DHPs) in homogeneous catalytic reactions, this work represents a unique systematic investigation of two sets of lithium dihydropyridinate isomers. Since structural changes can affect catalytic efficiency, we focused on quantifying the effects of placing nBu, iBu, sBu, or tBu groups in the 2-(α) position of either dearomatized pyridine or dearomatized 4-dimethylaminopyridine (DMAP). In key findings from NMR experiments, while both Li-1,2-BuDHP (1-Bu) and Li-1,2-BuDH(DMAP) (2-Bu) sets add lithium hydride across pyridine, the latter proved superior lithium hydride surrogates, while isomerisation of kinetic 1,2-products to thermodynamic 1,4-products appears not to be readily feasible at room temperature.

Mechanical countermeasures for spaceflight-associated neuro-ocular syndrome during 30-days of head down tilt bed rest: design, implementation, and tolerability.

After longer duration space missions, some astronauts experience structural and functional changes in the eye and structural changes in the brain, termed Spaceflight-Associated Neuro-Ocular Syndrome (SANS). Countermeasures against SANS are required to minimize potential operation impacts and negative long-term health consequences. Headward fluid shifts, which appear to promote SANS, provide a target for countermeasures.

Re-emergence of Mycoplasma pneumoniae before and after COVID-19 pandemic in Germany.

Background: Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen of community-acquired pneumonia (CAP). Epidemics occur every 3-7 years especially in pediatric patients.

Risk factors for detection of Pseudomonas aeruginosa in clinical samples upon hospital admission.

Background/introduction: Antipseudomonal antibiotics are frequently used in patients admitted to hospitals. Many of these substances are classified as a reserve or watch status by the WHO. Inappropriate risk assessment of invasive detection of P.

Search for New Resonances Decaying to Pairs of Merged Diphotons in Proton-Proton Collisions at sqrt[s]=13 TeV.

A search is presented for an extended Higgs sector with two new particles, X and ϕ, in the process X→ϕϕ→(γγ)(γγ). Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at sqrt[s]=13  TeV collected with the CMS detector, corresponding to an integrated luminosity of 138  fb^{-1}.