The synthesis and gas-transport properties of new metathesis-type polynorbornenes bearing fluoroorganic side groups are reported. The necessary monomers, fluorosubstituted exo-norbornene derivatives ...(exo-tricyclononenes), were obtained using one-step method based on stereo- and regioselective 2 + 2+2-cycloaddition of quadricyclane and fluoroalkenes. A set of high molecular weight polymers with different side groups were prepared from the synthesized F-substituted exo-tricyclononenes over the 1-st generation Grubbs catalyst. Permeability and diffusion coefficients of various gases (He, H2, O2, N2, CO2, CH4) in these poly-exo-tricyclononenes were determined for the first time and new relationships between polymer structure and gas permeability were established. Metathesis poly-exo-tricyclononene bearing four CF3-groups in each monomer unit displayed the highest gas permeability for the tested gases among metathesis polynorbornenes with F-organic substituents reported so far.
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•Novel highly reactive fluoro-containing exo-tricyclononenes were synthesized via 2 + 2+2-cycloaddition reaction.•A group of new metathesis polytricyclononenes bearing side fluoroorganic-substituents was prepared.•The obtained polymers possessed both the chemical and thermal stability.•The synthesized metathesis polytricyclononenes with fluorooganic-substituents exhibited the improved gas permeability.•New structure-property relationships for polynorbornenes were established.
The new neutron-deficient isotope
249
No was synthesized for the first time in the fusion-evaporation reaction
204
Pb(
48
Ca,3n)
249
No. After separation, using the kinematic separator SHELS, the new ...isotope was identified with the GABRIELA detection system through genetic correlations with the known daughter and granddaughter nuclei
245
Fm and
241
Cf. The alpha-decay activity of
249
No has an energy of 9129(22) keV and half-life 38.3(2.8) ms. An upper limit of 0.2% was measured for the fission branch of
249
No. Based on the present data and recent information on the decay properties of
253
Rf and aided by Geant4 simulations, the ground state of
249
No is assigned the 5/2
+
622 neutron configuration and a partial decay scheme from
253
Rf to
245
Fm could be established. The production cross-section was found to be
σ
(3n)=0.47(4) nb at a mid-target beam energy of 225.4 MeV, which corresponds to the maximum of the calculated excitation function. Correlations of the
249
No alpha activity with subsequent alpha decays of energy 7728(20) keV and half-life
1
.
2
-
0.4
+
1.0
min provided a firm measurement of the electron-capture or
β
+
branch of
245
Fm to
245
Es. The excitation function for the 1n, 2n and 3n evaporation channels was measured. In the case of the 2n-evaporation channel
250
No, a strong variation of the ground state and isomeric state populations as a function of bombarding energy could be evidenced.
Abstract
Objectives
Older adults often have difficulty remembering the details of recently encountered objects. We previously found this with the Mnemonic Similarity Task (MST). Surprisingly, the ...older adults’ MST Lure Discrimination Index (LDI) was significantly correlated with visual acuity but not with memory or executive function. Here we ran a replication with new, larger samples of young (N = 45) and older adults (N = 70). We then combined the original and replication older adult samples (N = 108) to critically examine the relative contributions of visual acuity, memory, and executive function composite scores to LDI performance using dominance analysis. This provided, to our knowledge, the first direct statistical comparison of all 3 of these factors and their interactions on LDI.
Methods
Participants completed the MST and a battery assessing visual acuity, memory, and executive function. We examined age group differences on MST performance in the new (i.e., replication) young and older adult samples and performed multiple regression and dominance analysis on the combined older adult sample.
Results
Consistent with previous findings, the older adults showed significantly poorer LDI but preserved item recognition. LDI was significantly correlated with both memory and executive function but not with visual acuity. In the combined older adult sample, all 3 composites predicted LDI, but dominance analysis indicated that executive function was the most important predictor.
Discussion
Older adults’ MST LDI difficulty may be predicted by their executive function and visual acuity. These factors should be considered when interpreting older adults’ MST performance.
Episodic memory is vulnerable to aging and may be influenced by age-related decline in the neurotransmitter acetylcholine. We probed this relation using a novel, minimally invasive transcranial ...magnetic stimulation marker of brain acetylcholine: short-latency afferent inhibition (SAI). We used neuropsychological testing to construct a composite score of episodic memory in
N
= 19 community-dwelling older adults, and stratified older adults into Higher- (
N
= 9) versus Lower-memory (
N
= 10) groups before SAI. The Higher-memory group showed significantly stronger SAI than the Lower-memory group, indicating an association between higher brain acetylcholine levels and better episodic memory. The two memory groups were equivalent in the potential confounds of age, education, mood, subjective sleep quality, and executive function. These data converge with others to suggest that episodic memory is related to acetylcholine in older adults. This relation should be further investigated, especially with pharmacology and neuroimaging.
Aim.
To study the prognostic significance of cardiovascular risk factors (RFs) in the formation of all-cause and cardiovascular mortality based on the results of a 27-year prospective cohort study of ...Tomsk population of both sexes aged 20-59 years.
Material and methods
. The object of study was random house-to-house sample of Tomsk population. In total, 1546 people (630 men and 916 women) aged 20-59 were examined. In 1988-1991, the prevalence of following cardiovascular RFs was studied: hypertension (HTN), overweight, smoking, alcohol consumption, hypercholesterolemia (HCE), low high-density lipoprotein cholesterol levels (hypo-HDL-emia), hypertriglyceridemia (HTG). All examination methods used were strictly standardized. To determine the RF, the criteria generally accepted in epidemiological studies were used. Over 27 years of follow-up, 330 deaths were recorded, including 142 due to cardiovascular disease.
Results.
In the multivariate Cox proportional hazard model, the following variables were studied: HTN, overweight, smoking, alcohol consumption, HCE, hypo-HDL-emia, HTG, coronary artery disease (CAD) (according to epidemiological criteria), and age. The strongest predictor of of all-cause death was frequent alcohol use (relative risk (RR) 2,75). Smoking increased the risk of death by 2,72 times. Among former smokers, the risk of all-cause death was 1,9 times higher compared to non-smokers. HTN increases the death risk by 1,61 times. Each year of life lived increases the death risk by 1,06 times. The most significant risk factor for death from CVD was frequent alcohol consumption (RR 3,01). Smoking increases the cardiovascular death risk by 2,28 times. Among former smokers, the RR of cardiovascular death was 1,91. HTN increases the risk of cardiovascular mortality by 1,84 times compared with people with normal blood pressure. Each year of life lived increases the risk of cardiovascular death by 1,1 times. In multivariate analysis, overweight, HCE, hypo-HDL-emia, HTG did not have a significant independent effect on the all-cause and cardiovascular death risk.
Conclusion.
In a 27-year cohort prospective study, independent predictors of all-cause and cardiovascular mortality, along with hypertension and age, were lifestyle risk factors, such as smoking and frequent alcohol consumption.
Recent expansion of fundamental knowledge on the physiology of lactation, and breast milk exosomes, stem cell biology, mother-child interactions from prenatal period to postnatal development requires ...a progressive, dynamic view from the scientific community and practicing physicians when analyzing known, generally accepted clinical phenomena and patterns (development of the immune system of infants and young children, natural and artificial feeding, features of postnatal development and growth of organs and tissues in children born prematurely). The components of the mother-breast-milk-infant triad are closely related to each other and influence developmental trajectory of the infant. According to modern concepts, breast milk of a nursing woman is a “living, metabolic / endocrine signaling system”, which may be considered an “immune organ” significant for postnatal growth and body programming of a premature baby. A valuable phenomenon of early postnatal development is actively discussed in the special literature, i,e., “microchimerism” caused by breastfeeding which, according to modern concepts, may play a key role in development of immune system and the whole body. Absence of protective (immunomodulatory and regenerative) effects of breast milk from a nursing woman on the spontaneous, uncorrectable impact of adverse factors of prematurity is likely predispose for remodeling and dysfunction of heart in prematurely born children, and, at longer range, in adults. The young children born prematurely show a unique cardiac phenotype characterized by reduced biventricular volume, relatively lower systolic and diastolic function, disproportionate muscle mass gain, clinically manifesting by increased risk of cardiovascular disease, hypertension, and decreased exercise tolerance. Hence, the premature birth may be considered a chronic disease state. Therefore, the natural feeding which provides a natural evolutionarily protective mechanism for the child’s heart should be attributed to the fundamental factors that play a vital role in prevention of cardiovascular diseases in prematurely born children and at later life periods.
An increase in the birth rate of premature and low birth weight children at the current level of medical development requires the development of fundamental ideas about the physiology of the ...cardiovascular system in a history of preterm birth from the point of view of pre- and postnatal ontogenesis. For practicing neonatologists, pediatricians, therapists, cardiologists, reproductologists, etc., it is necessary to improve the traditional ideas about the mechanisms of damage to the cardiovascular system in this category of patients. Because it is established that this clinical subgroup is characterized by increased risks of early onset of pathology of the heart and blood vessels, as well as a high mortality rate in adulthood. Pathological changes of the cardiovascular system in conditions of prematurity can occur at various levels of integration of the body (molecular, subcellular, cellular, organ, functional systems, organismal). The use of modern noninvasive technology of “spot tracing” makes it possible to study the features of segmental deformation and the variety of forms of left ventricle (LV) torsion mechanics during postnatal growth and development in prematurely born children. Optimization of research and diagnostic processes in the field of mechanics of the infant heart in the prenatal and postnatal periods from the point of view of progressive data on anatomy, histology, and clinical biochemistry allows us to study the nature of various contractile–rotational models, as well as reasonably assume the contribution of the fibrous skeleton of the infant heart to the formation of “childhood types” of left ventricular twisting. The search and development of informative criteria for the early diagnosis of latent subclinical heart dysfunction in childhood, taking into account the possibilities of non-invasive ultrasound technology of spot tracing (analysis of types of rotational movement, determination of areas of reduced longitudinal deformation of the LV), based on the current provisions of evidence-based medicine, have become quite possible in modern conditions and are demonstrated by the authors in this review. The information offered to the readers will allow them to expand the understanding of the physiology and pathophysiology of the infant heart with a history of premature birth, bearing in mind the fact that prematurity is considered a chronic condition.
Studies of radioactive ions (RIs) are the most thriving field of low-energy nuclear physics. In this paper, the concept and the scientific agenda of the prospective accelerator and storage ring ...facility for RI beam (RIB) research are proposed for a large-scale international project based at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research. The motivation for the new facility is discussed and its characteristics are briefly presented and shown to be comparable to those of advanced world centers, the so-called "RIB factories". In the project, the emphasis is made on studies with short-lived RIBs in storage rings. A unique feature of the project is the possibility of studying electron-RI interactions in a collider experiment to determine the fundamental properties of nuclear matter, in particular, electromagnetic form factors of exotic nuclei.
Abstract
We present a detailed prompt emission and early optical afterglow analysis of the two very-high-energy (VHE) detected bursts GRB 201015A and GRB 201216C, and their comparison with a subset ...of similar bursts. Time-resolved spectral analysis of multistructured GRB 201216C using the Bayesian binning algorithm revealed that during the entire duration of the burst, the low-energy spectral index (
α
pt
) remained below the limit of the synchrotron line of death. However, statistically some of the bins supported the additional thermal component. Additionally, the evolution of spectral parameters showed that both the peak energy (
E
p
) and
α
pt
tracked the flux. These results were further strengthened using the values of the physical parameters obtained by synchrotron modeling of the data. Our earliest optical observations of both bursts using the F/Photometric Robotic Atmospheric Monitor Observatorio del Roque de los Muchachos and Burst Observer and Optical Transient Exploring System robotic telescopes displayed a smooth bump in their early optical light curves, consistent with the onset of the afterglow due to synchrotron emission from an external forward shock. Using the observed optical peak, we constrained the initial bulk Lorentz factors of GRB 201015A and GRB 201216C to Γ
0
= 204 and Γ
0
= 310, respectively. The present early optical observations are the earliest known observations constraining outflow parameters and our analysis indicate that VHE detected bursts could have a diverse range of observed luminosity within the detectable redshift range of present VHE facilities.
Aim
. To study the interdependence of spousal body mass and influence of spouse overweight on the death risk according to the 27-year cohort prospective study.
Material and methods.
We examined a ...random household sample (n=1546; married couples, 427). Overweight frequency among spouses was studied on the first stage of the study (1988-1991). In 2002-2005 (stage II), the examination was repeated and overweight dynamics were studied. In 2015 (stage III), we analyze mortality rates and significance of overweight and spousal overweight for the mortality risk formation. Overweight was detected in people with body mass index ≥25 kg/m2. Two hundred deaths were recorded during 27-year follow-up. Vital status was established for 97% of observed persons.
Results
. Overweight was detected in 61,1% of men who lived with overweight wife and in 45% of men whose wife had normal body mass (p<0,01). Overweight was diagnosed more often in women whose husband also had overweight comparing with women who lived with normal weight husband (76,2% vs 61,7%; p<0,001). The risk of overweight formation among individuals whose spouse’s body mass increased from norm to overweight was in 3,04 times higher than in persons whose spouse had a stable normal body mass and in 2,2 times higher than in participants whose spouse had overweight on study stages I and II. Relative risk of mortality in men who lived with overweight wife was 2,07.
Conclusion
. 1) We found the body mass concordance in spouses. 2) The average body mass index in men and women who lived with overweight spouse is higher than in men and women whose spouse had a normal body mass. 3) Interdependence of spousal body mass was revealed in dynamics. 4) Spousal overweight is an independent predictor of premature mortality in men.
