368 research outputs found

    High-field vortices in Josephson junctions with alternating critical current density

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    We study long Josephson junctions with the critical current density alternating along the junction. New equilibrium states, which we call the field synchronized or FS states, are shown to exist if the applied field is from narrow intervals centered around equidistant series of resonant fields, HmH_m. The values of HmH_m are much higher than the flux penetration field, HsH_s. The flux per period of the alternating critical current density, ϕi\phi_i, is fixed for each of the FS states. In the mm-th FS state the value of ϕi\phi_i is equal to an integer amount of flux quanta, ϕi=mϕ0\phi_i =m\phi_0. Two types of single Josephson vortices carrying fluxes ϕ0\phi_0 or/and ϕ0/2\phi_0/2 can exist in the FS states. Specific stepwise resonances in the current-voltage characteristics are caused by periodic motion of these vortices between the edges of the junction.Comment: 4 pages, 5 figure

    Maximum supercurrent in Josephson junctions with alternating critical current density

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    We consider theoretically and numerically magnetic field dependencies of the maximum supercurrent across Josephson tunnel junctions with spatially alternating critical current density. We find that two flux-penetration fields and one-splinter-vortex equilibrium state exist in long junctions.Comment: 11 pages, 8 figure

    Menstrual Dysfunction and Treatment Among Adolescents With Congenital Heart Disease

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    Study Objective This study describes menstrual dysfunction and treatment among adolescent and young adult (AYA) females with congenital heart disease (CHD). Design Data collected from a 1-time survey completed by AYA females (and mothers if AYA unable). Setting Participants were recruited from pediatric cardiology clinics. Participants Female AYA with CHD, aged 14-21 years (N = 114). Interventions None. Main Outcome Measures The questionnaire assessed sexual and reproductive health (SRH) concerns, behaviors, and management. Outcome measures were self-reported menstrual complaints, use of over-the-counter (OTC) pain relief medications for dysmenorrhea, reported visits with a clinician for a menstrual problem, and reported use of hormones for menstrual problems or birth control. Results Mean age was 17.0 years (SD = 2.2). The majority of participants (83%) reported 1 or more menstrual complaints (67.5% cramping, 42.1% irregular menses, 46.5% heavy periods), and 88% reported any history of taking OTC medications for pain relief. Increased menstrual complaints were not associated with level of cardiac complexity, reported transplantation, or reported use of hormonal contraception. However, 32% of participants reported use of hormonal contraception for menstrual dysfunction. Combined oral contraceptive pills (COCs) were the most common; 2 of these women carried contraindications to estrogen. Conclusions A large majority of AYA females with CHD reported menstrual dysfunction. Use of OTC medication for menstrual pain and inappropriate use of estrogen creates concerns that menstrual disorders may be unaddressed or addressed inappropriately. Thus, gynecological needs of adolescents with CHD may need to be specifically targeted by providers who feel comfortable with this population and their complex needs

    Sequential addition of neuronal stem cell temporal cohorts generates a feed-forward circuit in the Drosophila larval nerve cord

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    How circuits self-assemble starting from neuronal stem cells is a fundamental question in developmental neurobiology. Here, we addressed how neurons from different stem cell lineages wire with each other to form a specific circuit motif. In Drosophila larvae, we combined developmental genetics (Twin spot MARCM, Multi-color Flip Out, permanent labeling) with circuit analysis (calcium imaging, connectomics, network science). For many lineages, neuronal progeny are organized into subunits called temporal cohorts. Temporal cohorts are subsets of neurons born within a tight time window that have shared circuit level function. We find sharp transitions in patterns of input connectivity at temporal cohort boundaries. In addition, we identify a feed-forward circuit that encodes the onset of vibration stimuli. This feed-forward circuit is assembled by preferential connectivity between temporal cohorts from different lineages. Connectivity does not follow the often-cited early-to-early, late-to-late model. Instead, the circuit is formed by sequential addition of temporal cohorts from different lineages, with circuit output neurons born before circuit input neurons. Further, we generate new tools for the fly community. Our data raise the possibility that sequential addition of neurons (with outputs oldest and inputs youngest) could be one fundamental strategy for assembling feed-forward circuits

    Monoamines, BDNF, Dehydroepiandrosterone, DHEA-Sulfate, and Childhood Depression—An Animal Model Study

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    Basal levels of monoamines and DHEA in four main limbic brain regions were measured in prepubertal Wistar Kyoto (WKY) rats (a putative animal model of childhood depression). Basal levels of “Brain-Derived Neurotrophic Factor (BDNF)” were also determined in two regions in the hippocampus, compared with Wistar strain controls. In the second phase, we examined the responsiveness of prepubertal WKY rats to different types of chronic antidepressant treatments: Fluoxetine, Desipramine, and dehydroepiandrosterone sulfate (DHEAS). WKY prepubertal rats exhibited different monoamine levels in the limbic system, reduced DHEA levels in the VTA and lower levels of BDNF in the hippocampus CA3 region compared to controls. In prepubertal WKY rats, only treatment with DHEAS produced a statistically significant decrease in immobility, compared to saline-administered controls in the forced swim test. Wistar controls were not affected by any antidepressant. The results imply that DHEA(S) and BDNF may be involved in the pathophysiology and pharmacotherapy of childhood depression

    Efficacy and safety of metabolic interventions for the treatment of severe COVID-19: in vitro, observational, and non-randomized open-label interventional study

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    Background: Viral infection is associated with a significant rewire of the host metabolic pathways, presenting attractive metabolic targets for intervention. Methods: We chart the metabolic response of lung epithelial cells to SARS-CoV-2 infection in primary cultures and COVID-19 patient samples and perform in vitro metabolism-focused drug screen on primary lung epithelial cells infected with different strains of the virus. We perform observational analysis of Israeli patients hospitalized due to COVID-19 and comparative epidemiological analysis from cohorts in Italy and the Veteran's Health Administration in the United States. In addition, we perform a prospective non-randomized interventional open-label study in which 15 patients hospitalized with severe COVID-19 were given 145 mg/day of nanocrystallized fenofibrate added to the standard of care. Results: SARS-CoV-2 infection produced transcriptional changes associated with increased glycolysis and lipid accumulation. Metabolism-focused drug screen showed that fenofibrate reversed lipid accumulation and blocked SARS-CoV-2 replication through a PPARα-dependent mechanism in both alpha and delta variants. Analysis of 3233 Israeli patients hospitalized due to COVID-19 supported in vitro findings. Patients taking fibrates showed significantly lower markers of immunoinflammation and faster recovery. Additional corroboration was received by comparative epidemiological analysis from cohorts in Europe and the United States. A subsequent prospective non-randomized interventional open-label study was carried out on 15 patients hospitalized with severe COVID-19. The patients were treated with 145 mg/day of nanocrystallized fenofibrate in addition to standard-of-care. Patients receiving fenofibrate demonstrated a rapid reduction in inflammation and a significantly faster recovery compared to patients admitted during the same period. Conclusions: Taken together, our data suggest that pharmacological modulation of PPARα should be strongly considered as a potential therapeutic approach for SARS-CoV-2 infection and emphasizes the need to complete the study of fenofibrate in large randomized controlled clinical trials. Funding: Funding was provided by European Research Council Consolidator Grants OCLD (project no. 681870) and generous gifts from the Nikoh Foundation and the Sam and Rina Frankel Foundation (YN). The interventional study was supported by Abbott (project FENOC0003). Clinical trial number: NCT04661930

    Neuroactive steroids in depression and anxiety disorders: Clinical studies

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    Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel

    Selective complexation of divalent cations by a cyclic α,β-peptoid hexamer: a spectroscopic and computational study

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    We describe the qualitative and quantitative analysis of the complexation properties towards cations of a cyclic peptoid hexamer composed of alternating α- and β-peptoid monomers, which bear exclusively chiral (S)-phenylethyl side chains (spe) that have no noticeable chelating properties. The binding of a series of monovalent and divalent cations was assessed by 1H NMR, circular dichroism, fluorescence and molecular modelling. In contrast to previous studies on cations binding by 18-membered α-cyclopeptoid hexamers, the 21-membered cyclopeptoid cP1 did not complex monovalent cations (Na+, K+, Ag+) but showed selectivity for divalent cations (Ca2+, Ba2+, Sr2+ and Mg2+). Hexacoordinated C-3 symmetrical complexes were demonstrated for divalent cations with ionic radii around 1 Å (Ca2+ and Ba2+), while 5-coordination is preferred for divalent cations with larger (Ba2+) or smaller ionic radii (Mg2+)

    Mobile-based technologies to support healthcare provider to healthcare provider communication and management of care

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    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of mobile-based technologies versus standard practice for supporting communication and client management in healthcare providers

    Targeted client communication via mobile devices for improving maternal, neonatal, and child health.

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    BACKGROUND: The global burden of poor maternal, neonatal, and child health (MNCH) accounts for more than a quarter of healthy years of life lost worldwide. Targeted client communication (TCC) via mobile devices (MD) (TCCMD) may be a useful strategy to improve MNCH. OBJECTIVES: To assess the effects of TCC via MD on health behaviour, service use, health, and well-being for MNCH. SEARCH METHODS: In July/August 2017, we searched five databases including The Cochrane Central Register of Controlled Trials, MEDLINE and Embase. We also searched two trial registries. A search update was carried out in July 2019 and potentially relevant studies are awaiting classification. SELECTION CRITERIA: We included randomised controlled trials that assessed TCC via MD to improve MNCH behaviour, service use, health, and well-being. Eligible comparators were usual care/no intervention, non-digital TCC, and digital non-targeted client communication. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane, although data extraction and risk of bias assessments were carried out by one person only and cross-checked by a second. MAIN RESULTS: We included 27 trials (17,463 participants). Trial populations were: pregnant and postpartum women (11 trials conducted in low-, middle- or high-income countries (LMHIC); pregnant and postpartum women living with HIV (three trials carried out in one lower middle-income country); and parents of children under the age of five years (13 trials conducted in LMHIC). Most interventions (18) were delivered via text messages alone, one was delivered through voice calls only, and the rest were delivered through combinations of different communication channels, such as multimedia messages and voice calls. Pregnant and postpartum women TCCMD versus standard care For behaviours, TCCMD may increase exclusive breastfeeding in settings where rates of exclusive breastfeeding are less common (risk ratio (RR) 1.30, 95% confidence intervals (CI) 1.06 to 1.59; low-certainty evidence), but have little or no effect in settings where almost all women breastfeed (low-certainty evidence). For use of health services, TCCMD may increase antenatal appointment attendance (odds ratio (OR) 1.54, 95% CI 0.80 to 2.96; low-certainty evidence); however, the CI encompasses both benefit and harm. The intervention may increase skilled attendants at birth in settings where a lack of skilled attendants at birth is common (though this differed by urban/rural residence), but may make no difference in settings where almost all women already have a skilled attendant at birth (OR 1.00, 95% CI 0.34 to 2.94; low-certainty evidence). There were uncertain effects on maternal and neonatal mortality and morbidity because the certainty of the evidence was assessed as very low. TCCMD versus non-digital TCC (e.g. pamphlets) TCCMD may have little or no effect on exclusive breastfeeding (RR 0.92, 95% CI 0.79 to 1.07; low-certainty evidence). TCCMD may reduce 'any maternal health problem' (RR 0.19, 95% CI 0.04 to 0.79) and 'any newborn health problem' (RR 0.52, 95% CI 0.25 to 1.06) reported up to 10 days postpartum (low-certainty evidence), though the CI for the latter includes benefit and harm. The effect on health service use is unknown due to a lack of studies. TCCMD versus digital non-targeted communication No studies reported behavioural, health, or well-being outcomes for this comparison. For use of health services, there are uncertain effects for the presence of a skilled attendant at birth due to very low-certainty evidence, and the intervention may make little or no difference to attendance for antenatal influenza vaccination (RR 1.05, 95% CI 0.71 to 1.58), though the CI encompasses both benefit and harm (low-certainty evidence). Pregnant and postpartum women living with HIV TCCMD versus standard care For behaviours, TCCMD may make little or no difference to maternal and infant adherence to antiretroviral (ARV) therapy (low-certainty evidence). For health service use, TCC mobile telephone reminders may increase use of antenatal care slightly (mean difference (MD) 1.5, 95% CI -0.36 to 3.36; low-certainty evidence). The effect on the proportion of births occurring in a health facility is uncertain due to very low-certainty evidence. For health and well-being outcomes, there was an uncertain intervention effect on neonatal death or stillbirth, and infant HIV due to very low-certainty evidence. No studies reported on maternal mortality or morbidity. TCCMD versus non-digital TCC The effect is unknown due to lack of studies reporting this comparison. TCCMD versus digital non-targeted communication TCCMD may increase infant ARV/prevention of mother-to-child transmission treatment adherence (RR 1.26, 95% CI 1.07 to 1.48; low-certainty evidence). The effect on other outcomes is unknown due to lack of studies. Parents of children aged less than five years No studies reported on correct treatment, nutritional, or health outcomes. TCCMD versus standard care Based on 10 trials, TCCMD may modestly increase health service use (vaccinations and HIV care) (RR 1.21, 95% CI 1.08 to 1.34; low-certainty evidence); however, the effect estimates varied widely between studies. TCCMD versus non-digital TCC TCCMD may increase attendance for vaccinations (RR 1.13, 95% CI 1.00 to 1.28; low-certainty evidence), and may make little or no difference to oral hygiene practices (low-certainty evidence). TCCMD versus digital non-targeted communication TCCMD may reduce attendance for vaccinations, but the CI encompasses both benefit and harm (RR 0.63, 95% CI 0.33 to 1.20; low-certainty evidence). No trials in any population reported data on unintended consequences. AUTHORS' CONCLUSIONS: The effect of TCCMD for most outcomes is uncertain. There may be improvements for some outcomes using targeted communication but these findings were of low certainty. High-quality, adequately powered trials and cost-effectiveness analyses are required to reliably ascertain the effects and relative benefits of TCCMD. Future studies should measure potential unintended consequences, such as partner violence or breaches of confidentiality
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