FT-IR and FT-Raman spectra of the biomolecule 5-aminouracil were recorded in the regions 400–4000
cm
−1 and 10–3500
cm
−1, respectively. The observed vibrational wavenumbers were analyzed and ...assigned to different normal modes of vibration of the molecule. Density functional calculations were performed to support wavenumber assignments of the observed bands. A comparison with the molecule of uracil was made, and specific scale factors were employed in the predicted wavenumbers of 5-aminouracil. With the purpose of study the important molecule 5-aminouracil, its equilibrium geometry and harmonic wavenumbers were calculated for the first time by the B3LYP DFT method. The vibrational wavenumbers were compared with IR and Raman experimental data. Also good reproduction of the experimental wavenumbers is obtained and the % error is very small. All the tautomeric forms of 5-aminouracil were determined and optimized. The dimer forms were also simulated. The energy, atomic charges and dipole moments were discussed and several general conclusions were underlined.
Abstract Decreased levels of alpha-synuclein (aSyn) in cerebrospinal fluid (CSF) in Parkinson's disease and related synucleinopathies have been reported, however, not consistently in all ...cross-sectional studies. To test the performance of one recently released human-specific enzyme-linked immunosorbent assay (ELISA) for the quantification of aSyn in CSF, we carried out a round robin trial with 18 participating laboratories trained in CSF ELISA analyses within the BIOMARKAPD project in the EU Joint Program - Neurodegenerative Disease Research. CSF samples (homogeneous aliquots from pools) and ELISA kits (one lot) were provided centrally and data reported back to one laboratory for data analysis. Our study showed that although factors such as preanalytical sample handling and lot-to-lot variability were minimized by our study design, we identified high variation in absolute values of CSF aSyn even when the same samples and same lots of assays were applied. We further demonstrate that although absolute concentrations differ between laboratories the quantitative results are comparable. With further standardization this assay may become an attractive tool for comparing aSyn measurements in diverse settings. Recommendations for further validation experiments and improvement of the interlaboratory results obtained are given.
The Delta (B.1.617.2) variant was the predominant UK circulating SARS-CoV-2 strain between May and December 2021. How Delta infection compares with previous variants is unknown. This prospective ...observational cohort study assessed symptomatic adults participating in the app-based COVID Symptom Study who tested positive for SARS-CoV-2 from May 26 to July 1, 2021 (Delta overwhelmingly the predominant circulating UK variant), compared (1:1, age- and sex-matched) with individuals presenting from December 28, 2020 to May 6, 2021 (Alpha (B.1.1.7) the predominant variant). We assessed illness (symptoms, duration, presentation to hospital) during Alpha- and Delta-predominant timeframes; and transmission, reinfection, and vaccine effectiveness during the Delta-predominant period. 3581 individuals (aged 18 to 100 years) from each timeframe were assessed. The seven most frequent symptoms were common to both variants. Within the first 28 days of illness, some symptoms were more common with Delta versus Alpha infection (including fever, sore throat, and headache) and some vice versa (dyspnoea). Symptom burden in the first week was higher with Delta versus Alpha infection; however, the odds of any given symptom lasting ≥ 7 days was either lower or unchanged. Illness duration ≥ 28 days was lower with Delta versus Alpha infection, though unchanged in unvaccinated individuals. Hospitalisation for COVID-19 was unchanged. The Delta variant appeared more (1.49) transmissible than Alpha. Re-infections were low in all UK regions. Vaccination markedly reduced the risk of Delta infection (by 69-84%). We conclude that COVID-19 from Delta or Alpha infections is similar. The Delta variant is more transmissible than Alpha; however, current vaccines showed good efficacy against disease. This research framework can be useful for future comparisons with new emerging variants.
Introduction
Biological sex is an increasingly recognized factor driving clinical and structural heterogeneity in Alzheimer's disease, but its role in the behavioral variant of frontotemporal ...dementia (bvFTD) is unknown.
Methods
We included 216 patients with bvFTD and 235 controls with magnetic resonance imaging (MRI) from a large multicenter cohort. We compared the clinical characteristics and cortical thickness between men and women with bvFTD and controls. We followed the residuals approach to study behavioral and cognitive reserve.
Results
At diagnosis, women with bvFTD showed greater atrophy burden in the frontotemporal regions compared to men despite similar clinical characteristics. For a similar amount of atrophy, women demonstrated better‐than‐expected scores on executive function and fewer changes in apathy, sleep, and appetite than men.
Discussion
Our findings suggest that women might have greater behavioral and executive reserve than men, and neurodegeneration must be more severe in women to produce symptoms similar in severity to those in men.
The effect of the sulphur atom on 2-thiouracil (2TU) and 2-thiouridine molecules, as compared with uracil and uridine molecules, respectively, was carried out in several environments. The predicted ...IR spectrum of 2TU in the isolated state was compared with that obtained for uracil molecule and with those reported experimentally in matrix isolation. Its crystal unit cell in the solid state was simulated through a tetramer form using DFT methods for the first time. The calculated Raman spectrum was compared to the experimental ones in the solid state. A linear scaling procedure was used for this task. The first hydration shell was simulated by explicit number of water molecules surrounding 2TU up to 30 and was compared with that obtained in uracil molecule. Water molecules 'distributed' around 2TU was preferred over that 'clustering', because it can better reproduce the hydration and their effects on different parameters of the molecular structure of 2TU and uracil. The total atomic charges and several calculated thermodynamic parameters were discussed. The effect of the sulphur atom on the Watson-Crick (WC) and reverse WC base pair uridine-adenosine was estimated, and the CP corrected interaction energies were calculated. 2-thiouridine has a weaker WC pair than that with uridine, although its slight higher dipole moment (μ) facilitates the interaction with the water molecules. Several helical parameters were determined.
Silicon carbide dust is ubiquitous in circumstellar envelopes around C-rich AGB stars. However, the main gas-phase precursors leading to the formation of SiC dust have not yet been identified. The ...most obvious candidates among the molecules containing an Si-C bond detected in C-rich AGB stars are SiC
, SiC, and Si
C. To date, the ring molecule SiC
has been observed in a handful of evolved stars, while SiC and Si
C have only been detected in the C-star envelope IRC +10216.
We aim to study how widespread and abundant SiC
, SiC, and Si
C are in envelopes around C-rich AGB stars and whether or not these species play an active role as gas-phase precursors of silicon carbide dust in the ejecta of carbon stars.
We carried out sensitive observations with the IRAM 30m telescope of a sample of 25 C-rich AGB stars to search for emission lines of SiC
, SiC, and Si
C in the
2 mm band. We performed non-LTE excitation and radiative transfer calculations based on the LVG method to model the observed lines of SiC
and to derive SiC
fractional abundances in the observed envelopes.
We detect SiC
in most of the sources, SiC in about half of them, and do not detect Si
C in any source, at the exception of IRC +10216. Most of these detections are reported for the first time in this work. We find a positive correlation between the SiC and SiC
line emission, which suggests that both species are chemically linked, the SiC radical probably being the photodissociation product of SiC
in the external layer of the envelope. We find a clear trend in which the denser the envelope, the less abundant SiC
is. The observed trend is interpreted as an evidence of efficient incorporation of SiC
onto dust grains, a process which is favored at high densities owing to the higher rate at which collisions between particles take place.
The observed behavior of a decline in the SiC
abundance with increasing density strongly suggests that SiC
is an important gas-phase precursor of SiC dust in envelopes around carbon stars.
Context. Asymptotic giant branch (AGB) stars lose their envelopes by means of a stellar wind whose driving mechanism is not understood well. Characterizing the composition and thermal and dynamical ...structure of the outflow provides constraints that are essential for understanding AGB evolution, including the rate of mass loss and isotopic ratios. Aims. We characterize the CO emission from the wind of the low mass-loss rate oxygen-rich AGB star W Hya using data obtained by the HIFI, PACS, and SPIRE instruments on board the Herschel Space Observatory and ground-based telescopes. 12CO and 13CO lines are used to constrain the intrinsic 12C/13C ratio from resolved HIFI lines. Methods. We combined a state-of-the-art molecular line emission code and a dust continuum radiative transfer code to model the CO lines and the thermal dust continuum. Results. The acceleration of the outflow up to about 5.5 km s-1 is quite slow and can be represented by a β-type velocity law with index β = 5. Beyond this point, acceleration up the terminal velocity of 7 km s-1 is faster. Using the J = 10–9, 9–8, and 6–5 transitions, we find an intrinsic 12C/13C ratio of 18 ± 10 for W Hya, where the error bar is mostly due to uncertainties in the 12CO abundance and the stellar flux around 4.6 μm. To match the low-excitation CO lines, these molecules need to be photo-dissociated at ~500 stellar radii. The radial dust emission intensity profile of our stellar wind model matches PACS images at 70 μm out to 20′′ (or 800 stellar radii). For larger radii the observed emission is substantially stronger than our model predicts, indicating that at these locations there is extra material present. Conclusions. The initial slow acceleration of the wind may imply inefficient dust formation or dust driving in the lower part of the envelope. The final injection of momentum in the wind might be the result of an increase in the opacity thanks to the late condensation of dust species. The derived intrinsic isotopologue ratio for W Hya is consistent with values set by the first dredge-up and suggestive of an initial mass of 2 M⊙ or more. However, the uncertainty in the isotopologic ratio is large, which makes it difficult to set reliable limits on W Hya’s main-sequence mass.
The objective of this study was to determine the efficacy and safety of a novel method of facial rejuvenation using a 2940-nm erbium:YAG laser with Spatially Modulated Ablation™. A pilot study was ...performed in 16 women with moderate to severe signs of facial aging relative to chronological age, who underwent two treatment sessions with an Er:YAG laser coupled to the RecoSMA™ technology (Linline, Minsk, Belarus). The whole face was treated in all patients. Clinical efficacy, tolerance, adverse effects, complications, and histological changes due to the treatment were evaluated. Clinical photographs and biopsies were taken before treatment and 3 months after the second treatment session. All patients completed the study and presented no significant complications. Histological changes in the epidermis and dermis as a result of treatment were found. Fine lines, wrinkles, and overall facial aging improved significantly (
p
< 0.0001). The mean reduction of fine lines and wrinkles was 59 % (
r
= 40–75 %). The mean improvement of overall facial aging was 74 % (
r
= 55–90 %). After showing the patients the comparative photographs before and after treatment, 75 % of women stated that they were satisfied or very satisfied and would recommend the treatment. Preliminary results show an excellent safety/efficacy profile for this novel technology, which, based on observed results, can be considered to have advantages over other methods of facial rejuvenation with lasers.
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