On extensions of triangular norms on bounded lattices

Smallest and largest possible extensions of triangular norms on bounded lattices are discussed. As such ordinal and horizontal sum like constructions for t-norms on bounded lattices are investigated. Necessary and sufficient conditions for the lattice guaranteeing that the extension is again a t-norm are revealed.     

Photo‐induced and Rapid Labeling of Tetrazine‐Bearing Proteins via Cyclopropenone‐Caged Bicyclononynes

Inverse electron‐demand Diels–Alder cycloadditions (iEDDAC) between tetrazines and strained alkenes/alkynes have emerged as essential tools for studying and manipulating biomolecules. A light‐triggered version of iEDDAC (photo‐iEDDAC) is presented that confers spatio‐temporal control to bioorthogonal labeling in vitro and in cellulo. A cyclopropenone‐caged dibenzoannulated bicyclo[6.1.0]nonyne probe (photo‐DMBO) was designed that is unreactive towards tetrazines before light‐activation, but engages in iEDDAC after irradiation at 365 nm. Aminoacyl tRNA synthetase/tRNA pairs were discovered for efficient site‐specific incorporation of tetrazine‐containing amino acids into proteins in living cells. In situ light activation of photo‐DMBO conjugates allows labeling of tetrazine‐modified proteins in living E. coli. This allows proteins in living cells to be modified in a spatio‐temporally controlled manner and may be extended to photo‐induced and site‐specific protein labeling in animals.     

Influence of Air Temperature on the UV Exposure of Different Body Sites Due to Clothing of Young Women During Daily Errands

Clothing is one of the main influencing factors for personal ultraviolet radiation (UVR) exposure. Despite that, little attention was put on this topic till now. In this study, the clothing habits of young females have been investigated in dependence of meteorological conditions. Observations were made from spring to autumn during daylight in the urban region of Vienna, Austria. For this, a scheme dividing the body into six different sections was developed as well as a coding scale that corresponds to the different garments and indicates the body sites that are exposed. It was found that air temperature is the dominating factor for exposure. With increasing temperature, the first area of the body to be exposed to solar UVR is, aside from face and hands, the décolleté, followed by nape, ankles, instep and forearms. Observations further indicate that the frequency of people's being outdoors decreases significantly at temperatures higher than 30°C. This paper provides detailed frequency distributions of uncovered body sites in dependence of temperature. These can be used together with measurements of temperature and UVR to calculate the relative exposure at any time and at many locations, and could help to explain the body distribution of UVR caused skin alterations.     

Construction of 4-substituted 2-(pyrrolidine-3-yl)acetic acid derivatives as cyclic γ-aminobutyric acid analogues employing intermolecular [2+2]-photocycloaddition as key steps

The synthesis of new 2-(pyrrolidine-3-yl)acetic acid derivatives as cyclic γ-aminobutyric acid analogues, which are additionally substituted at the 4-position, is reported. A de Mayo reaction, i.e. a combination of an intermolecular [2+2]-photocycloaddition of 1,3-dioxinones with N-protected 3-pyrroline and a fragmentation reaction of the resulting cyclobutane moiety, represent the key steps.     

Monomeric β-Diketiminato Group 13 Metal Dipnictogenide Complexes with Two Terminal EH2 Groups (E=P,As)

The pnictogenyl Group 13 compounds (Dipp₂Nacnac)M[E(SiMe₃)₂]Cl and (Dipp₂Nacnac)M(EH₂)₂ (Dipp₂Nacnac=HC[C(Me)N(Ar)]₂, Ar: Dipp=2,6-iPr₂C₆H₃; M=Al, Ga, In; E=P, As) were successfully synthesized. The salt metathesis between (Dipp₂Nacnac)MCl₂ and LiE(SiMe₃)₂ only led to monosubstituted compounds (Dipp₂Nacnac)M[E(SiMe₃)₂]Cl [E=P, M=Ga( 1 ), In ( 2 ); E=As, M=Ga ( 3 ), In ( 4 )], regardless of the stoichiometric ratios used. In contrast to the steric effect of the SiMe₃ groups in 1 – 4 , the reactions of the corresponding halides with LiPH₂⋅DME (or KAsH₂) facilely yielded the dipnictogenide compounds (Dipp₂Nacnac)M(EH₂)₂ (E=P, M=Al ( 5 ), Ga ( 6 ), In ( 7 ); E=As, M=Al ( 8 ), Ga ( 9 )), avoiding the use of flammable and toxic PH₃ and AsH₃ for their synthesis. The compounds 5 – 9 are the first examples of monomeric Group 13 diphosphanides and diarsanides in which the metal center is bound to two terminal PH₂ and AsH₂ groups, respectively. In contrast to the successful synthesis of the indium diphosphanide (Dipp₂Nacnac)In(PH₂)₂, the reaction of (Dipp₂Nacnac)InCl₂ with KAsH₂ led to an indium mirror due to the instability of the target product.     

Is the axial zero-field splitting parameter of tetragonally elongated high-spin manganese(III) complexes always negative?

The positive axial zero-field splitting parameter D relevant for the S = 2 ground state of [Mn(cyclam)I2]I (cyclam = 1,4,8,11-tetraazacyclotetradecane) is interpreted using the valence bond configuration interaction model which explicitly considers the covalency of the manganese-iodide bond.     

The effect of oral administration of calcium and magnesium on intestinal oxalate absorption in humans

Calcium oxalate (CaOx) urolithiasis is the most common urinary stone disease (70-75 % of all stones consist of CaOx in countries with western diet). Oxalate is the most lithogenic substance in CaOx crystallisation in urine. Oxalate is either synthesized within the body or absorbed from food. As oxalate is not metabolized in the human body, it appears unchanged in urine. Conventional analysis methods cannot distinguish between endogenous and exogenous oxalate. Our [13C2]oxalate absorption test enabled measurement of intestinal oxalate absorption and quantification of the influence of Ca- and Mg-supplementation on it. The effects of the oral administration of these supplements were compared in order to obtain valid data for recommendations for CaOx urolithiasis patients. A 10 mmol supplement of both ions decreased the oxalate absorption significantly, calcium being more than twice as effective.