182 research outputs found

    Doppler-free Yb Spectroscopy with Fluorescence Spot Technique

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    We demonstrate a simple technique to measure the resonant frequency of the 398.9 nm 1S0 - 1P1 transition for the different Yb isotopes. The technique, that works by observing and aligning fluorescence spots, has enabled us to measure transition frequencies and isotope shifts with an accuracy of 60 MHz. We provide wavelength measurements for the transition that differ from previously published work. Our technique also allows for the determination of Doppler shifted transition frequencies for photoionisation experiments when the atomic beam and laser beam are not perpendicular and furthermore allows us to determine the average velocity of the atoms along the direction of atomic beam

    Versatile ytterbium ion trap experiment for operation of scalable ion-trap chips with motional heating and transition-frequency measurements

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    We present the design and operation of an ytterbium ion trap experiment with a setup offering versatile optical access and 90 electrical interconnects that can host advanced surface and multilayer ion trap chips mounted on chip carriers. We operate a macroscopic ion trap compatible with this chip carrier design and characterize its performance, demonstrating secular frequencies >1 MHz, and trap and cool nearly all of the stable isotopes, including 171Yb+ ions, as well as ion crystals. For this particular trap we measure the motional heating rate 〈ṅ〉 and observe an 〈ṅ〉∝1/ω2 behavior for different secular frequencies ω. We also determine a spectral noise density SE(1 MHz)=3.6(9)×10-11 V2 m-2 Hz-1 at an ion electrode spacing of 310(10) μm. We describe the experimental setup for trapping and cooling Yb+ ions and provide frequency measurements of the 2S1/2↔2P1/2 and 2D3/2↔3D[3/2]1/2 transitions for the stable 170Yb+, 171Yb+, 172Yb+, 174Yb+, and 176Yb+ isotopes which are more precise than previously published work

    Cortisol concentrations in human skeletal muscle tissue after phonophoresis with 10% hydrocortisone gel

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    CONTEXT: The delivery of hydrocortisone through phonophoresis is a widely prescribed technique for the treatment of various musculoskeletal inflammatory conditions. However, limited scientific evidence exists to support the efficacy of phonophoresis in delivering hydrocortisone to skeletal muscle tissue in humans. OBJECTIVE: To determine hydrocortisone (cortisol) concentrations in human skeletal muscle tissue after a phonophoresis treatment using 10% hydrocortisone gel. DESIGN: Randomized design in which 12 subjects were randomly assigned to either an ultrasound (sham) treatment or a 10% hydrocortisone phonophoresis treatment. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Twelve healthy subjects (8 women, 4 men: age = 22.3 +/- 2.64 years, height = 168.28 +/- 8.19 cm, mass = 69.58 +/- 9.05 kg) with no history of musculoskeletal disease, preexisting inflammatory conditions, or recent orthopaedic injuries. INTERVENTION(S): Ultrasound at 1.0 MHz, 1.0 W/cm (2), at a continuous setting for 7 minutes was applied to a standardized area of the vastus lateralis muscle in both groups. The contralateral limb served as the control (no treatment) for both the sham and the phonophoresis groups. MAIN OUTCOME MEASURE(S): Vastus lateralis muscle biopsies were taken from both legs immediately after treatment, and cortisol concentrations were analyzed using an enzyme-linked immunosorbent assay. RESULTS: We observed no significant difference in muscle cortisol concentration between the contralateral control limb and the treatment limb in either the sham or the phonophoresis group ( P \u3e .05). No significant difference was noted when the treatment limbs in the sham and phonophoresis groups were compared ( P \u3e .05). CONCLUSIONS: Our data suggest that a 10% hydrocortisone-based phonophoresis treatment did not increase cortisol concentrations in human skeletal muscle tissue

    Association of preterm birth with ADHD-like cognitive impairments and additional subtle impairments in attention and arousal malleability

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    BACKGROUND: Whilst preterm-born individuals have an increased risk of developing attention-deficit/hyperactivity disorder (ADHD), and are reported to have ADHD-like attention and arousal impairments, direct group comparisons are scarce. METHODS: We directly compared preterm-born adolescents (n = 186) to term-born adolescents with ADHD (n = 69), and term-born controls (n = 135), aged 11-23, on cognitive-performance, event-related potential and skin conductance level (SCL) measures associated with attention and arousal. The measures are from baseline and fast-incentive conditions of a four-choice reaction time task, previously shown to discriminate between the individuals with ADHD and controls. We aimed to establish whether preterm-born adolescents show: (a) identical cognitive-neurophysiological impairments to term-born adolescents with ADHD (b) possible additional impairments, and whether (c) the observed impairments correlate with ADHD symptom scores. RESULTS: The preterm group, like the term-born ADHD group, showed increased mean reaction time (MRT) and reaction time variability (RTV) in the baseline condition, and attenuated contingent negative variation (CNV) amplitude (response preparation) in the fast-incentive condition. The preterm group, only, did not show significant within-group adjustments in P3 amplitude (attention allocation) and SCL (peripheral arousal). Dimensional analyses showed that ADHD symptoms scores correlated significantly with MRT, RTV and CNV amplitude only. CONCLUSIONS: We find impairments in cognition and brain function in preterm-born adolescents that are linked to increased ADHD symptoms, as well as further impairments, in lack of malleability in neurophysiological processes. Our findings indicate that such impairments extend at least to adolescence. Future studies should extend these investigations into adulthood

    Impairments in error processing and their association with ADHD symptoms in individuals born preterm

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    <p>(<b>A</b>) Grand average response-locked event-related potentials (ERPs) of the error-related positivity (Pe) at the Cz electrode between 150 and 450 ms for the preterm group (represented by dotted lines), the ADHD group (attention-deficit/hyperactivity disorder represented by dashed lines) and the control group (shown in solid lines), and (<b>B</b>) topographic maps for each group.</p

    Is association of preterm birth with cognitive-neurophysiological impairments and ADHD symptoms consistent with a causal inference or due to familial confounds?

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    BACKGROUND: Preterm birth is associated with an increased risk for cognitive-neurophysiological impairments and attention-deficit/hyperactivity disorder (ADHD). Whether the associations are due to the preterm birth insult per se, or due to other risk factors that characterise families with preterm-born children, is largely unknown. METHODS: We employed a within-sibling comparison design, using cognitive-performance and event-related potential (ERP) measures from 104 preterm-born adolescents and 104 of their term-born siblings. Analyses focused on ADHD symptoms and cognitive and ERP measures from a cued continuous performance test, an arrow flanker task and a reaction time task. RESULTS: Within-sibling analyses showed that preterm birth was significantly associated with increased ADHD symptoms (β = 0.32, p = 0.01, 95% CI 0.05 to 0.58) and specific cognitive-ERP impairments, such as IQ (β = -0.20, p = 0.02, 95% CI -0.40 to -0.01), preparation-vigilance measures and measures of error processing (ranging from β = 0.71, -0.35). There was a negligible within-sibling association between preterm birth with executive control measures of inhibition (NoGo-P3, β = -0.07, p = 0.45, 95% CI -0.33 to 0.15) or verbal working memory (digit span backward, β = -0.05, p = 0.63, 95% CI -0.30 to 0.18). CONCLUSIONS: Our results suggest that the relationship between preterm birth with ADHD symptoms and specific cognitive-neurophysiological impairments (IQ, preparation-vigilance and error processing) is independent of family-level risk and consistent with a causal inference. In contrast, our results suggest that previously observed associations between preterm birth with executive control processes of inhibition and working memory are instead linked to background characteristics of families with a preterm-born child rather than preterm birth insult per se. These findings suggest that interventions need to target both preterm-birth specific and family-level risk factors

    A Multidisciplinary Approach to Resolving the End-Guadalupian Extinction

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    The transition from the middle to late Permian (Guadalupian–Lopingian) is claimed to record one or more extinction events that rival the ‘Big Five’ in terms of depletion of biological diversity and reorganization of ecosystem structure. Yet many questions remain as to whether the events recorded in separate regions were synchronous, causally related, or were of a magnitude rivaling other major crises in Earth\u27s history. In this paper, we survey some major unresolved issues related to the Guadalupian–Lopingian transition and offer a multidisciplinary approach to advance understanding of this under-appreciated biotic crisis by utilizing records in Southern Hemisphere high-palaeolatitude settings. We focus on the Bowen-Gunnedah-Sydney Basin System (BGSBS) as a prime site for analyses of biotic and physical environmental change at high palaeolatitudes in the middle and terminal Capitanian. Preliminary data suggest the likely position of the mid-Capitanian event is recorded in regressive deposits at the base of the Tomago Coal Measures (northern Sydney Basin) and around the contact between the Broughton Formation and the disconformably overlying Pheasants Nest Formation (southern Sydney Basin). Initial data suggest that the end-Capitanian event roughly correlates to the transgressive “Kulnura Marine Tongue” in the middle of the Tomago Coal Measures (northern Sydney Basin) and strata bearing dispersed, ice-rafted gravel in the Erins Vale Formation (southern Sydney Basin). Preliminary observations suggest that few plant genera or species disappeared in the transition from the Guadalupian to Lopingian, and the latter interval saw an increase in floristic diversity

    Factors associated with cognitive decline and delirium after transcatheter aortic valve implantation: Preliminary evidence

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    Background: Transcatheter aortic valve implantation (TAVI) has become the standard for treating severe symptomatic aortic stenosis in those with prohibitive surgical risk. Cognitive complications, including delirium and cognitive decline are common following TAVI, yet an understanding of pre-procedural factors associated with these outcomes is lacking. This prospective observational study set out to identify geriatric pre-procedural factors associated with post-procedural delirium and cognitive decline in patients undergoing TAVI. / Methods: Cognitive outcomes of TAVI patients aged ≥60 years (N=32) were measured over one-year post-TAVI. Pre-procedural measures included frailty, gait, visual symptoms, voice pitch, dysphagia, blink rate, mood, and sleep. Primary outcomes were post-procedural delirium and cognitive decline. / Results: Delirium was present in 25% of patients over two days following TAVI and 26% experienced cognitive decline in the year post-TAVI. Daily physical activity was a protective factor against cognitive decline, and worse baseline visual memory was associated with delirium. While non-significant and with very large confidence intervals, moderate to large effect sizes were found for associations between slowed gait speed, pre-existing atrial fibrillation, and dysphagia for delirium, and slower gait speed, higher blink rate, pre-existing atrial fibrillation for cognitive decline. / Conclusion: Though underpowered, measures of considerable effect size were identified (although non-significant and with large variability). In larger studies, these novel geriatric factors could further be explored for predicting cognitive complications following TAVI. Improvement of risk prediction for cognitive decline and delirium following TAVI could assist with early identification of those at risk, informing clinical decision-making and allowing for targeted intervention to reduce post-procedural incidence of these complications

    Development of the Ketamine Side Effect Tool (KSET)

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    Background: Currently, no specific, systematic assessment tool for the monitoring and reporting of ketamine-related side effects exists. Our aim was to develop a comprehensive Ketamine Side Effect Tool (KSET) to capture acute and longer-term side effects associated with repeated ketamine treatments. Methods: Informed by systematic review data and clinical research, we drafted a list of the most commonly reported side effects. Face and content validation were obtained via feedback from collaborators with expertise in psychiatry and anaesthetics, clinical trial piloting and a modified Delphi Technique involving ten international experts. Results: The final version consisted of four forms that collect information at time points: screening, baseline, immediately after a single treatment, and longer-term follow-up. Instructions were developed to guide users and promote consistent utilisation. Limitations: Further evaluation of feasibility, construct validity and reliability is required, and is planned across multiple international sites. Conclusions: The structured Ketamine Side Effect Tool (KSET) was developed, with confirmation of content and face validity via a Delphi consensus process. This tool is timely, given the paucity of data regarding ketamine's safety, tolerability and abuse potential over the longer term, and its recent adoption internationally as a clinical treatment for depression. Although based on data from depression studies, the KSET has potential applicability for ketamine (or derivatives) used in other medical disorders, including chronic pain. We recommend its utilisation for both research and clinical scenarios, including data registries
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