Forces on a boiling bubble in a developing boundary layer, in microgravity with g-jitter and in terrestrial conditions

Terrestrial and microgravity flow boiling experiments were carried out with the same test rig, comprising a locally heated artificial cavity in the center of a channel near the frontal edge of an intrusive glass bubble generator. Bubble shapes were in microgravity generally not far from those of truncated spheres,which permitted the computation of inertial lift and drag from potential flow theory for truncated spheres approximating the actual shape. For these bubbles, inertial lift is counteracted by drag and both forces are of the same order of magnitude as g-jitter. A generalization of the Laplace equation is found which applies to a deforming bubble attached to a plane wall and yields the pressure difference between the hydrostatic pressures in the bubble and at the wall, p. A fully independent way to determine the overpressure p is given by a second Euler-Lagrange equation. Relative differences have been found to be about 5% for both terrestrial and microgravity bubbles. A way is found to determine the sum of the two counteracting major force contributions on a bubble in the direction normal to the wall from a single directly measurable quantity. Good agreement with expectation values for terrestrial bubbles was obtained with the difference in radii of curvature averaged over the liquid-vapor interface, (1/R2 − 1/R1), multiplied with the surface tension coefficient, σ. The new analysis methods of force components presented also permit the accounting for a surface tension gradient along the liquid-vapor interface. No such gradients were found for the present measurements

The use of a direct bronchial challenge test in primary care to diagnose asthma

Many asthmatics in primary care have mild symptoms and lack airflow obstruction. If variable expiratory airflow limitation cannot be determined by spirometry or peak expiratory flow, despite a history of respiratory symptoms, a positive bronchial challenge test (BCT) can confirm the diagnosis of asthma. However, BCT is traditionally performed in secondary care. In this observational real-life study, we retrospectively analyze 5-year data of a primary care diagnostic center carrying out BCT by histamine provocation. In total, 998 primary care patients aged ≥16 years underwent BCT, without any adverse events reported. To explore diagnostic accuracy, we examine 584 patients with a high pretest probability of asthma. Fifty-seven percent of these patients have a positive BCT result and can be accurately diagnosed with asthma. Our real-life data show BCT is safe and feasible in a suitably equipped primary care diagnostic center. Furthermore, it could potentially reduce diagnostic referrals to secondary care

Atomic diffraction from nanostructured optical potentials

We develop a versatile theoretical approach to the study of cold-atom diffractive scattering from light-field gratings by combining calculations of the optical near-field, generated by evanescent waves close to the surface of periodic nanostructured arrays, together with advanced atom wavepacket propagation on this optical potential.Comment: 8 figures, 10 pages, submitted to Phys. Rev.

Reactive scattering of H2 from Cu(100): comparison of dynamics calculations based on the specific reaction parameter approach to density functional theory with experiment

We present new experimental and theoretical results for reactive scattering of dihydrogen from Cu(100). In the new experiments, the associative desorption of H2 is studied in a velocity resolved and final rovibrational state selected manner, using time-of-flight techniques in combination with resonance-enhanced multi-photon ionization laser detection. Average desorption energies and rota- tional quadrupole alignment parameters were obtained in this way for a number of (v = 0, 1) ro- tational states, v being the vibrational quantum number. Results of quantum dynamics calculations based on a potential energy surface computed with a specific reaction parameter (SRP) density func- tional, which was derived earlier for dihydrogen interacting with Cu(111), are compared with the results of the new experiments and with the results of previous molecular beam experiments on sticking of H2 and on rovibrationally elastic and inelastic scattering of H2 and D2 from Cu(100). The calculations use the Born-Oppenheimer and static surface approximations. With the functional derived semi-empirically for dihydrogen + Cu(111), a chemically accurate description is obtained of the molecular beam experiments on sticking of H2 on Cu(100), and a highly accurate descrip- tion is obtained of rovibrationally elastic and inelastic scattering of D2 from Cu(100) and of the orientational dependence of the reaction of (v = 1, j = 2 − 4) H2 on Cu(100). This suggests that a SRP density functional derived for H2 interacting with a specific low index face of a metal will yield accurate results for H2 reactively scattering from another low index face of the same metal, and that it may also yield accurate results for H2 interacting with a defected (e.g., stepped) surface of that same metal, in a system of catalytic interest. However, the description that was obtained of the average desorption energies, of rovibrationally elastic and inelastic scattering of H2 from Cu(100), and of the orientational dependence of reaction of (v = 0, j = 3 − 5, 8) H2 on Cu(100) compares less well with the available experiments. More research is needed to establish whether more accurate SRP-density functional theory dynamics results can be obtained for these observables if surface atom motion is added to the dynamical model. The experimentally and theoretically found dependence of the rotational quadrupole alignment parameter on the rotational quantum number provides evidence for rotational enhancement of reaction at low translational energies.Fil: Sementa, L.. Leiden University; Países Bajos. Istituto per i Processi Chimico-Fisici of the Consiglio Nazionale delle Ricerche; ItaliaFil: Wijzenbroek, M.. Leiden University; Países BajosFil: Van Kolck, B. J.. Leiden University; Países BajosFil: Somers, M. F.. Leiden University; Países BajosFil: Al-Halabi, A.. Leiden University; Países BajosFil: Busnengo, Heriberto Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Olsen, R. A.. Leiden University; Países Bajos. SINTEF Materials and Chemistry; NoruegaFil: Kroes, G. J.. Leiden University; Países BajosFil: Rutkowski, M.. Westfalische Wilhelms Universitat; AlemaniaFil: Thewes, C.. Westfalische Wilhelms Universitat; AlemaniaFil: Kleimeier, N. F.. Westfalische Wilhelms Universitat; AlemaniaFil: Zacharias, H.. Westfalische Wilhelms Universitat; Alemani

Parents' expectations of the outpatient care for daytime urinary incontinence in children:A qualitative study

INTRODUCTION: Daytime urinary incontinence (UI) can have an enormous impact on a child's life, lowering both self-esteem and quality of life. Although most children start therapy after their first visit to our outpatient clinic, no studies have reported on parents' or patients' expectations of care for daytime UI in this setting. OBJECTIVE: We aimed to explore the expectations of the parents of children referred to an outpatient clinic for daytime UI. STUDY DESIGN: This was a qualitative study that involved performing semi-structured interviews with the parents of children who had been referred for daytime UI (with or without nocturnal enuresis). Interviews took place between July 2018 and October 2018 and continued until saturation was reached. The results were transcribed verbatim and analyzed according to Giorgi's strategy of phenomenological data analysis. RESULTS: Nine parents of children, aged 5-12 years old, were interviewed, revealing "(Experienced) Health," Self-management," and "Social Impact" as the main themes that influenced parental expectations. All parents wanted to know if there was a medical explanation for UI, some were satisfied when diagnostics revealed no underlying condition, and others wanted treatment. Parents expressed no preferences about diagnostics or the content and duration of treatment, but they hoped that any previously attempted ineffective steps would not be repeated. Some parents defined treatment success as their child becoming completely dry, but most stated that learning coping strategies was more important. DISCUSSION: This is the first study to explore the expectations of parents when attending outpatient care for children with daytime UI. We employed a strong theoretical framework with a clear interview guide. The main limitations are that we only interviewed parents and that this was a qualitative study, precluding the drawing of firm conclusions. Nevertheless, our results point to the need for quantitative evaluation. CONCLUSION: Expectations seem to be influenced by (experienced) health, efforts at self-management, and the social impact of UI, making it critical that these themes are addressed. It was interesting to note that parents do not always attend outpatient departments with the goal of completely resolving daytime UI. Instead, some only want to know if there is an underlying medical condition or want to reduce the social impact by learning coping mechanisms. Excluding underlying medical conditions may therefore stimulate acceptance of watchful waiting without the need to start treatment

De novo variants disturbing the transactivation capacity of POU3F3 cause a characteristic neurodevelopmental disorder

POU3F3, also referred to as Brain-1, is a well-known transcription factor involved in the development of the central nervous system, but it has not previously been associated with a neurodevelopmental disorder. Here, we report the identification of 19 individuals with heterozygous POU3F3 disruptions, most of which are de novo variants. All individuals had developmental delays and/or intellectual disability and impairments in speech and language skills. Thirteen individuals had characteristic low-set, prominent, and/or cupped ears. Brain abnormalities were observed in seven of eleven MRI reports. POU3F3 is an intronless gene, insensitive to nonsense-mediated decay, and 13 individuals carried protein-truncating variants. All truncating variants that we tested in cellular models led to aberrant subcellular localization of the encoded protein. Luciferase assays demonstrated negative effects of these alleles on transcriptional activation of a reporter with a FOXP2-derived binding motif. In addition to the loss-of-function variants, five individuals had missense variants that clustered at specific positions within the functional domains, and one small in-frame deletion was identified. Two missense variants showed reduced transactivation capacity in our assays, whereas one variant displayed gain-of-function effects, suggesting a distinct pathophysiological mechanism. In bioluminescence resonance energy transfer (BRET) interaction assays, all the truncated POU3F3 versions that we tested had significantly impaired dimerization capacities, whereas all missense variants showed unaffected dimerization with wild-type POU3F3. Taken together, our identification and functional cell-based analyses of pathogenic variants in POU3F3, coupled with a clinical characterization, implicate disruptions of this gene in a characteristic neurodevelopmental disorder

Outer-Sphere Contributions to the Electronic Structure of Type Zero Copper Proteins

Bioinorganic canon states that active-site thiolate coordination promotes rapid electron transfer (ET) to and from type 1 copper proteins. In recent work, we have found that copper ET sites in proteins also can be constructed without thiolate ligation (called “type zero” sites). Here we report multifrequency electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), and nuclear magnetic resonance (NMR) spectroscopic data together with density functional theory (DFT) and spectroscopy-oriented configuration interaction (SORCI) calculations for type zero Pseudomonas aeruginosa azurin variants. Wild-type (type 1) and type zero copper centers experience virtually identical ligand fields. Moreover, O-donor covalency is enhanced in type zero centers relative that in the C112D (type 2) protein. At the same time, N-donor covalency is reduced in a similar fashion to type 1 centers. QM/MM and SORCI calculations show that the electronic structures of type zero and type 2 are intimately linked to the orientation and coordination mode of the carboxylate ligand, which in turn is influenced by outer-sphere hydrogen bonding

Мультипарадигмальний підхід до аналізу феномену нігілізму

У статті розглянуто нігілізм як неоднозначне й поліморфне поняття. Досліджено різні підходи до тлумачення та розв’язання питань, пов’язаних із нігілізмом. Розкрито людиномірність нігілізму в контексті відстеження варіативного смислового навантаження феномену. Встановлено, що нігілізм потрібно позиціонувати як спосіб пробудження людського духу, заперечення деструктивного конформізму й відсутності опору (пасивний песимізм).В статье рассмотрен нигилизм как неоднозначное и полиморфное понятие. Исследованы различные подходы к толкованию и решению вопросов, связанных с нигилизмом. Раскрыта человекомерность нигилизма в контексте отслеживания вариативной смысловой нагрузки феномена. Установлено, что нигилизм нужно позиционировать как способ пробуждения человеческого духа, отрицание деструктивного конформизма и отсутствия сопротивления (пассивный пессимизм).Nihilism is considered as ambiguous and polymorphic concept. Different approaches to the interpretation and solution of issues associated with nihilism are investigated. Human measurement of nihilism in the context of tracking meaning of varied semantic capacity of the phenomenon is revealed. It is determined that nihilism must be positioned as a way of awakening of the human spirit, denial of destructive conformism and absence of resistance (passive pessimism)