Abstract
Background
The current paper analyzed the effect of the pandemic-induced lockdown on maternal mental health during the first 12 postpartum weeks in Germany.
Methods
In this cohort study, we ...compared the participants’ anamnestic backgrounds and the results of psychological tests, measuring stress levels, depressive symptoms and attachment. The 327 participants were divided into two groups with one representing the “pre-COVID” sample and the other the “lockdown” sample. We performed multiple comparisons, investigating the distribution of diagnoses and the correlating risk profiles between the two cohorts.
Results
Our analysis showed a significant difference between the two cohorts, with a 13.2% increase in the prevalence of adjustment disorders (AD), but not postpartum depression (PPD), in the first 12 weeks postpartum. However, during the pandemic, women with AD had fewer risk factors compared to their pre-pandemic counterparts. In the “lockdown” cohort, a tendency toward higher stress and lower mother-child attachment was observed in AD.
Conclusions
In sum, we observed some negative impact of the pandemic on maternal mental health. The lockdown might have contributed to an increase in the number of cases involving AD in the postpartum period. The prevalence of PPD (ca. 6–10%), on the other hand, was not affected by the lockdown. Thus, the effect of COVID-19 on maternal mental health might not, after all, have been as severe as assumed at the beginning of the pandemic.
The emission of semiconducting polyfluorenes is often accompanied by an undesired feature in the green spectral region. Whereas a number of previous investigations have argued in favor of a ...monomolecular origin of the emission species based on ketonic defects, recent experimental results suggested the necessity of excimer formation between individual fluorenone units. We provide a range of new evidence supporting the monomolecular origin of green band emission in polyfluorenes. Most importantly, we succeed in performing single‐molecule spectroscopy on fluorenone‐containing polyfluorene model compounds. Whereas most fluorenone‐containing molecules exhibit both blue backbone and green fluorenone emission independent of fluorenone concentration, it is the relative intensities of the two species which correlate strongly with the fluorenone concentration on the single‐molecule level. Furthermore, we consider a novel model compound with a bifacial arrangement of two fluorenone units. This compound does not provide any signatures of enhanced intramolecular excimer formation but does strongly indicate that concentration quenching effects occur once fluorenone units can interact electronically. The ability to detect on‐chain defect emission in a single polymer molecule demonstrates that photochemical reactions in conjugated polymers can be monitored by fluorescence spectroscopy down to the level of a few atoms, constituting an unprecedented degree of materials characterization.
Single‐molecule spectroscopy of polyfluorenes (PFs) reveals two distinct coexisting emissive species originating from π–π* transitions in the blue region and localized on‐chain keto defects in the green (see Figure). Besides demonstrating the feasibility of detecting of impurities in large macromolecules on the single‐atom level, the results conclusively illustrate that green band emission from PFs does not arise from intermolecular interactions.
The present study was conducted to examine the association between dietary acid load (DAL) and markers of inflammation, oxidative stress, and malnutrition in a group of Iranian hemodialysis (HD) ...patients.
This cross-sectional study was performed on individuals aged ≥18 years who were on HD at least 6 months before their enrollment in the study. A 4-day dietary recall was used for the evaluation of dietary intake. DAL was calculated using two methods including potential renal acid load (PRAL) and net endogenous acid production (NEAP). For assessing the malnutrition status, we used the subjective global assessment (SGA), dialysis malnutrition score (DMS), and malnutrition inflammation score (MIS). Fasting blood samples were collected from each participant to assess serum levels of high-sensitivity C-reactive protein (hs-CRP), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), sE-selectin, malondialdehyde (MDA), nitric oxide (NO), and endothelin-1.
In total, 291 patients with a mean age of 57.73 ± 0.88 years and HD vintage of 4.27 ± 0.25 months were enrolled in the current study. Significant positive associations were observed between PRAL and hs-CRP (
= 1.77, 95% CI: 0.88, 2.65), sICAM-1 (
= 83.21, 95% CI: 10.39, 156.04), sVCAM-1 (
= 194.63, 95% CI: 74.68, 314.58), and sE-selectin (
= 6.66, 95% CI: 1.81, 11.50) among participants with the highest PRAL scores, compared to those with the lowest PRAL scores. NEAP was positively correlated with hs-CRP (
= 1.34, 95% CI: 0.46, 2.22), sICAM-1 (
= 88.83, 95% CI: 16.99, 160.67), and MDA (
= 0.35, 95% CI: 0.005, 0.71). Additionally, marginally significant higher odds of SGA (OR = 1.98, 95% CI: 0.95, 4.11) and DMS (OR = 1.94, 95% CI: 0.92, 4.05) were observed in individuals in the third tertile of PRAL vs. the first tertile of PRAL. NEAP had also a marginally significant positive correlation with DMS (OR = 2.01, 95% CI: 0.93, 4.31).
This study illustrates that higher consumption of acidic foods is correlated with markers of inflammation, oxidative stress, and malnutrition in HD patients.
Polycystic ovary syndrome (PCOS) is associated with reproductive disorders and adverse cardiometabolic risk factors that can negatively impact the general health of women. Inulin‐type fructans (ITFs) ...are proposed to beneficially affect risk factors associated with metabolic disorders. Whether ITFs can help with the management of PCOS by modifying insulin resistance (IR) and androgen levels has not yet been explored. The aim of this study was to investigate the effects of ITFs with different degrees of polymerization on insulin resistance, blood lipids, anthropometric measures, and hormonal status in overweight and obese women with PCOS. In a randomized double‐blind placebo‐controlled trial, seventy‐five women with PCOS aged 18–40 years old were randomly assigned to receive 10 g/day of high‐performance inulin (HPI) or oligofructose‐enriched inulin (OEI) or maltodextrin for 12 weeks. Biochemical and clinical outcomes were measured at baseline and after the intervention. Participants in the HPI and OEI groups experienced improvements in waist circumference, total testosterone, free androgen index, sex hormone‐binding globulin, and triglycerides compared to the placebo group. Also, the number of women with irregular menses or oligomenorrhoea decreased significantly in both ITF groups. Participants in the HPI group reported lower body mass, fasting insulin, and HOMA‐IR, as well as a higher quantitative insulin sensitivity check index. ITF supplementation, especially with long‐chain ITFs, when given for 12 weeks may improve metabolic outcomes, androgen status and clinical manifestations in women with PCOS.
Supplementation with inulin‐type fructans for 12 weeks improves weight loss, androgen status, and clinical manifestations of PCOS. The beneficial effects of high‐performance inulin on weight loss, insulin resistance, and hirsutism are more remarkable than those of oligofructose‐enriched inulin.
A fully conjugated para‐phenylene ladder polymer (P1) and the alternating copolymers {2,7‐9,9‐bis(2‐ethylhexyl)fluorene‐5,5′‐(2,2′‐bithiophene)} (P3) and ...{2,7‐9,9‐dioctylfluorene‐5,5′‐(2,2′‐bithiophene)} (P4) have been prepared via metal‐mediated cross‐coupling reactions, using microwaves as a heat source. The procedure, which yields polymeric material in ca. ten minutes, has no adverse effects on the quality of the polymers and displays a high degree of reproducibility. Transfer of the optimized conditions to the synthesis of a new naphthalene‐based polyarylene‐ketone (P2) and a (1,5‐dioctoxynaphthylene‐2,6‐diyl‐alt‐2,2′‐bithiophene‐5,5′‐diyl) copolymer (P5) confirmed the versatility of the procedure and the dramatic reduction in reaction times compared with conventional heating. In the case of the Stille‐type coupling reaction of the electron‐rich, less reactive dibromo monomer 1,5‐dioctoxy‐2,6‐dibromo‐naphthalene, the microwave‐assisted protocol results in a marked increase in both yield and molecular weight.
Microwave‐assisted protocols developed for the preparation of semiconducting polymers, in dramatically reduced reaction times and, in some cases, better yields and molecular weights, are reported. Synthesis is achieved via palladium‐mediated Suzuki‐ and Stille‐type reactions.
Digital radio antenna arrays, like LOPES (LOFAR PrototypE Station), detect high-energy cosmic rays via the radio emission from atmospheric extensive air showers. LOPES is an array of dipole antennas ...placed within and triggered by the KASCADE-Grande experiment on site of the Karlsruhe Institute of Technology, Germany. The antennas are digitally combined to build a radio interferometer by forming a beam into the air shower arrival direction which allows measurements even at low signal-to-noise ratios in individual antennas. This technique requires a precise time calibration. A combination of several calibration steps is used to achieve the necessary timing accuracy of about 1
ns. The group delays of the setup are measured, the frequency dependence of these delays (dispersion) is corrected in the subsequent data analysis, and variations of the delays with time are monitored. We use a transmitting reference antenna, a beacon, which continuously emits sine waves at known frequencies. Variations of the relative delays between the antennas can be detected and corrected for at each recorded event by measuring the phases at the beacon frequencies.
Context.The detection of radio pulses from cosmic ray air showers is a potentially powerful new detection mechanism for studying spectrum and composition of ultra high energy cosmic rays that needs ...to be understood in greater detail. The radiation consists in large part of geosynchrotron radiation. The intensity of this radiation depends, among other factors, on the energy of the primary particle and the angle of the shower axis with respect to the geomagnetic field. Aims.Since the radiation mechanism is based on particle acceleration, the atmospheric electric field can play an important role. Especially inside thunderclouds large electric fields can be present. In this paper we examine the contribution of an electric field to the emission mechanism theoretically and experimentally. Methods.Two mechanisms of amplification of radio emission are considered: the acceleration radiation of the shower particles and the radiation from the current that is produced by ionization electrons moving in the electric field. For both mechanisms analytical estimates are made of their effects on the radio pulse height. We selected lopes data recorded during thunderstorms, periods of heavy cloudiness and periods of cloudless weather. We tested whether the correlations with geomagnetic angle and primary energy vary with atmospheric conditions. Results.We find that during thunderstorms the radio emission can be strongly enhanced. The present data suggests that the observed amplification is caused by acceleration of the shower electrons and positrons. In the near future, extensions of lopes and the construction of lofar will help to identify the mechanism in more detail. No amplified pulses were found during periods of cloudless sky or heavy cloudiness, suggesting that the electric field effect for radio air shower measurements can be safely ignored during non-thunderstorm conditions.
Aims. We wish to study the spectral dependence of the radio emission from cosmic-ray air showers around $100~{\rm PeV}$ $(10^{17}~{\rm eV})$. Methods. We observe short radio pulses in a broad ...frequency band with the dipole-interferometer LOPES (LOFAR Prototype Station), which is triggered by a particle detector array named Karlsruhe Shower Core and Array Detector (KASCADE). LOFAR is the Low Frequency Array. For this analysis, 23 strong air shower events are selected using parameters from KASCADE. The radio data are digitally beam-formed before the spectra are determined by sub-band filtering and fast Fourier transformation. Results. The resulting electric field spectra fall off to higher frequencies. An average electric field spectrum is fitted with an exponential $E_{\nu}=K\cdot\mbox{exp}\,(\nu/\mathrm{MHz}/\beta)$ and $\beta=-0.017\pm0.004$, or alternatively, with a power law $\epsilon_{\nu}=K\cdot\nu^{\alpha}$ and a spectral index of $\alpha=-1\pm0.2$. The spectral slope obtained is not consistent within uncertainties and it is slightly steeper than the slope obtained from Monte Carlo simulations based on air showers simulated with CORSIKA (Cosmic Ray Simulations for KASCADE). For the analyzed sample of LOPES events, we do not find any significant dependence of the spectral slope on the electric field amplitude, the azimuth angle, the zenith angle, the curvature radius, nor on the average distance of the antennae from the shower core position. But one of the strongest events was measured during thunderstorm activity in the vicinity of LOPES and shows the longest pulse length measured of $110~\mathrm{ns}$ and a spectral slope of $\alpha=-3.6$. Conclusions. We show with two different methods that frequency spectra from air shower radio emission can be reconstructed on event-by-event basis, with only two dozen dipole antennae simultaneously over a broad range of frequencies. According to the obtained spectral slopes, the maximum power is emitted below 40 MHz. Furthermore, the decrease in power to higher frequencies indicates a loss in coherence determined by the shower disc thickness. We conclude that a broader bandwidth, larger collecting area, and longer baselines, as will be provided by LOFAR, are necessary to further investigate the relation of the coherence, pulse length, and spectral slope of cosmic ray air showers.
Relativistic, charged particles present in extensive air showers (EAS) lead to a coherent emission of radio pulses which are measured to identify the shower initiating high-energy cosmic rays. ...Especially during thunderstorms, there are additional strong electric fields in the atmosphere, which can lead to further multiplication and acceleration of the charged particles and thus have influence on the form and strength of the radio emission. For a reliable energy reconstruction of the primary cosmic ray by means of the measured radio signal it is very important to understand how electric fields affect the radio emission. In addition, lightning strikes are a prominent source of broadband radio emissions that are visible over very long distances. This, on the one hand, causes difficulties in the detection of the much lower signal of the air shower. On the other hand the recorded signals can be used to study features of the lightning development. The detection of cosmic rays via the radio emission and the influence of strong electric fields on this detection technique is investigated with the LOPES experiment in Karlsruhe, Germany. The important question if a lightning is initiated by the high electron density given at the maximum of a high-energy cosmic-ray air shower is also investigated, but could not be answered by LOPES. But, these investigations exhibit the capabilities of EAS radio antenna arrays for lightning studies. We report about the studies of LOPES measured radio signals of air showers taken during thunderstorms and give a short outlook to new measurements dedicated to search for correlations of lightning and cosmic rays.
A facile route has been developed for the preparation of a new family of oligophenyls based on a 2,5,2',5'-tetra-aryl substituted biphenyl structural motif. The cruciform terphenyl dimer ...2,5,2',5'-tetra(4-tert-butylphenyl)-1,1'-biphenyl () has been prepared in a two step protocol as a representative of this interesting class of materials. The thermal behaviour of the cruciform was analysed by DSC and shows that forms an amorphous glass when cooled from the isotropic melt. Subsequent heating reveals a glass transition temperature at 130 degrees C. X-Ray single crystal structure analysis of 2,2'-bis(4-tert-butylphenyl)-1,1'-biphenyl () and shows that both these molecules with a quater-phenyl substructure adopt a folded solid-state structure. Examining the (1)H NMR spectra of and reveals that the interactions that induce this folding in the solid-state are sufficiently strong to bias foldamer formation also in solution. Consequently, it is reasonable to assume that the folded conformation within the lattice is due to intramolecular pi-pi interaction rather than being imposed by crystal packing. The optical properties of the cruciform terphenyl dimer are discussed relative to the linear analogue 1,4-bis(4-tert-butylterphenyl)benzene ().
PDF
