On the role of coherence in the transition from kinetics to dynamics: Theory and application to femtosecond unimolecular reactions

We consider the relation between observed pump–probe signals in the femtosecond regime and the kinetics of unimolecular reactions, that is, the exponential decay of reactants and the exponential rise of the product population, respectively. It is shown that the signals cannot be fully accounted for within standard approaches of unimolecular decay, conventionally used in the past, since interference effects between the quasi-bound vibrational states within the bandwidth of the pump laser cannot be neglected. When these effects are included, all features of the signals can be accounted for. We apply this theoretical treatment of coherent interference to examine the dynamics and kinetics of the quasi-bound transition configurations, and relate them to the decay rates of individual quasi-bound resonance states. The signals show multi-exponential behavior, reflecting the different decay rates of the resonance states, with an average rate constant (within the bandwidth of the pump laser) which can be extracted directly from the signals. The persistence of coherence is evident in the observed signals. The predissociation of NaI is used as a prototype for numerical illustration

On the role of coherence in the transition from kinetics to dynamics: Theory and application to femtosecond unimolecular reactions

We consider the relation between observed pump–probe signals in the femtosecond regime and the kinetics of unimolecular reactions, that is, the exponential decay of reactants and the exponential rise of the product population, respectively. It is shown that the signals cannot be fully accounted for within standard approaches of unimolecular decay, conventionally used in the past, since interference effects between the quasi-bound vibrational states within the bandwidth of the pump laser cannot be neglected. When these effects are included, all features of the signals can be accounted for. We apply this theoretical treatment of coherent interference to examine the dynamics and kinetics of the quasi-bound transition configurations, and relate them to the decay rates of individual quasi-bound resonance states. The signals show multi-exponential behavior, reflecting the different decay rates of the resonance states, with an average rate constant (within the bandwidth of the pump laser) which can be extracted directly from the signals. The persistence of coherence is evident in the observed signals. The predissociation of NaI is used as a prototype for numerical illustration

Above ground Microbial Decay Test of Biocide Treated and Untreated Wood Exposed to Danish and Humid Tropical Climates

A co-operative study was initiated to compare the aboveground field decay test of untreated and preservative-treated timbers under Nordic (Danish) and a representative humid tropical (Malaysian) environment according to CEN standard method. Matched specimens of untreated and both preservative-impregnated and surface-treated wood were simultaneously exposed at The Danish Technological Institute (DTI) and The Forest Research Institute Malaysia (FRIM) campuses. The aim was to demonstrate conclusively that accelerated decay of untreated wood in field tests according to CEN methods prevailed under such tropical environments. It could be of considerable use to the Scandinavian and European manufacturers of wood protecting biocides intending to challenge treated test specimens to this tropical condition. Of significance, by the ENV12037 lap-joint method, pine sapwood lap-joints were deteriorated to rating 3 (adopting a 5-point decay/stain rating scale) within 1.5 years at FRIM, while corresponding specimens exposed at DTI showed no signs of deterioration (rating 0). After 37 months (3 years), spruce was starting to decay at FRIM (rating 2) but not at DTI. Specimens vacuum pressure treated according to the Nordic Hazard Class of NTR Class AB were not deteriorated after 3 years’ exposure at either DTI or FRIM. Painted specimens exposed at DTI already showed signs of peeling after 6 months, while initial peelings of the matched coated specimens exposed at FRIM were observed only after 1.5 years. The uniform tropical climate with a constant high relative humidity did not affect the adhesion of the coatings to the wood in the same way as the Danish climate. Indeed, there is a strong indication that the rate of fungal degradation (preferably soft rot decay and basidiomycete attack) is appreciably increased in Malaysian (humid tropical) compared to Danish (Nordic temperate) environments

Endothelial Cell Phenotypes Demonstrate Different Metabolic Patterns and Predict Mortality in Trauma Patients

Funding Information: HHH has been supported by a PhD-scholarship from Rigshospitalet, Denmark, and would like to thank The Candys Foundation for the grant (2018-279). IMdM and LKN were supported by The Novo Nordisk Foundation (NNF Grant numbers: NNF20CC0035580; NNF14OC0009473; and NNF20SA0066621). Publisher Copyright: © 2023 by the authors.In trauma patients, shock-induced endotheliopathy (SHINE) is associated with a poor prognosis. We have previously identified four metabolic phenotypes in a small cohort of trauma patients (N = 20) and displayed the intracellular metabolic profile of the endothelial cell by integrating quantified plasma metabolomic profiles into a genome-scale metabolic model (iEC-GEM). A retrospective observational study of 99 trauma patients admitted to a Level 1 Trauma Center. Mass spectrometry was conducted on admission samples of plasma metabolites. Quantified metabolites were analyzed by computational network analysis of the iEC-GEM. Four plasma metabolic phenotypes (A–D) were identified, of which phenotype D was associated with an increased injury severity score (p < 0.001); 90% (91.6%) of the patients who died within 72 h possessed this phenotype. The inferred EC metabolic patterns were found to be different between phenotype A and D. Phenotype D was unable to maintain adequate redox homeostasis. We confirm that trauma patients presented four metabolic phenotypes at admission. Phenotype D was associated with increased mortality. Different EC metabolic patterns were identified between phenotypes A and D, and the inability to maintain adequate redox balance may be linked to the high mortality.Peer reviewe

Presence of Antibodies Against Coxiella burnetii and Risk of Spontaneous Abortion: A Nested Case-Control Study

BACKGROUND AND AIMS: Q fever is a bacterial zoonosis caused by infection with Coxiella burnetii. It is well established that Q fever causes fetal loss in small ruminants. The suspicion has been raised that pregnant women may also experience adverse pregnancy outcome when the infection is acquired or reactivated during pregnancy. The purpose of this study was to assess the potential association between serologic markers of infection with C. burnetii and spontaneous abortion. METHODS: A nested case-control study within the Danish National Birth Cohort, a cohort of 100,418 pregnancies recruited from 1996-2002. Women were recruited in first trimester of pregnancy and followed prospectively. Median gestational age at enrolment was 8 weeks (25 and 75 percentiles: 7 weeks; 10 weeks). During pregnancy, a blood sample was collected at gestational week 6-12 and stored in a bio bank. For this study, a case sample of 218 pregnancies was drawn randomly among the pregnancies in the cohort which ended with a miscarriage before 22 gestational weeks, and a reference group of 482 pregnancies was selected in a random fashion among all pregnancies in the cohort. From these pregnancies, serum samples were screened for antibodies against C. burnetii in a commercial enzyme-linked immunosorbent assay (ELISA). Samples that proved IgG or IgM antibody positive were subsequently confirmatory tested by an immunofluorescence (IFA) test. RESULTS: Among cases, 11 (5%) were C. burnetii positive in ELISA of which one was confirmed in the IFA assay compared to 29 (6%) ELISA positive and 3 IFA confirmed in the random sample. CONCLUSIONS: We found no evidence of a higher prevalence of C. burnetii antibodies in serum samples from women who later miscarried and the present study does not indicate a major association between Q fever infection and spontaneous abortion in humans. Very early first trimester abortions were, however, not included in the study