178 research outputs found

    Recoil correction to the ground state energy of hydrogenlike atoms

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    The recoil correction to the ground state energy of hydrogenlike atoms is calculated to all orders in \alpha Z in the range Z = 1-110. The nuclear size corrections to the recoil effect are partially taken into account. In the case of hydrogen, the relativistic recoil correction beyond the Salpeter contribution and the nonrelativistic nuclear size correction to the recoil effect, amounts to -7.2(2) kHz. The total recoil correction to the ground state energy in hydrogenlike uranium (^{238}U^{91+}) constitutes 0.46 eV.Comment: 16 pages, 1 figure (eps), Latex, submitted to Phys.Rev.

    Postoperative diabetes insipidus: how to define and grade this complication?

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    Purpose Although transient diabetes insipidus (DI) is the most common complication of pituitary surgery, there is no consensus on its definition. Polyuria is the most overt symptoms of DI, but can also reflect several physiological adaptive mechanisms in the postoperative phase. These may be difficult to distinguish from and might coincide with DI. The difficulty to distinguish DI from other causes of postoperative polyuria might explain the high variation in incidence rates. This limits interpretation of outcomes, in particular complication rates between centers, and may lead to unnecessary treatment. Aim of this review is to determine a pathophysiologically sound and practical definition of DI for uniform outcome evaluations and treatment recommendations. Methods This study incorporates actual data and the experience of our center and combines this with a review of literature on pathophysiological mechanisms and definitions used in clinical studies reporting of postoperative DI. Results The occurrence of excessive thirst and/or hyperosmolality or hypernatremia are the best indicators to discriminate between pathophysiological symptoms and signs of DI and other causes. Urine osmolality distinguishes DI from osmotic diuresis. Conclusions To improve reliability and comparability we propose the following definition for postoperative DI: polyuria (urine production > 300 ml/hour for 3 h) accompanied by a urine specific gravity (USG) 300 mosmol/kg, or serum sodium > 145 mmol/L. To prevent unnecessary treatment with desmopressin, we present an algorithm for the diagnosis and treatment of postoperative DI.Diabetes mellitus: pathophysiological changes and therap

    Context reexposure to bolster contextual dependency of emotional episodic memory

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    Contextual overgeneralization of emotional memory is a core aspect of anxiety disorders. Identifying methods to enhance contextual dependency of emotional memory is therefore of significant clinical interest. Animal research points to a promising approach: reexposure to the context in which fear is acquired reduces generalization to other contexts. However, the exact conditions for this effect are unknown, complicating translation to effective interventions. Most notably, exposure to a context that resembles—but is not identical to—the learning context may diminish contextual dependency of memory by integration of additional contextual cues. Here, we therefore assessed in a large-scale study (N = 180) whether context reexposure enhances contextual dependency of emotional episodic memory whereas exposure to a similar context impairs it. We also tested whether relatively strong memory retrieval during context (re)exposure amplifies these effects. We replicated prior research showing that correct recognition depends on context and contextual dependency is lower for emotional than neutral memories. However, exposure to the encoding context or a similar context did not affect contextual dependency of memory, and retrieval strength did not interact with such effects. Thorough insight into factors underlying the effects of context (re)exposure on contextual dependency seems key to eventually attain a memory recontextualization intervention

    Isolated ileal blind loop inflammation after intestinal resection with ileocolonic anastomosis in Crohn's disease: an often neglected endoscopic finding with an unfavorable outcome

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    OBJECTIVE: Postoperative endoscopic recurrence in patients with Crohn's disease (CD) is commonly classified using the Rutgeerts score. Ulcerations in the ileal blind loop are not taken into account in the Rutgeerts score, and the clinical relevance of these lesions is unknown. This study aimed to assess the outcome of isolated ileal blind loop inflammation (IBLI) in postoperative CD patients. METHODS: Adult CD patients who underwent intestinal surgery with ileocolonic anastomosis between 1997 and 2017 were included and postoperative endoscopy reports were retrospectively reviewed. IBLI was defined as isolated inflammation of the ileal blind loop with or without ulcera confined to the anastomosis. Outcome was assessed using endoscopic recurrence (Rutgeerts >i2) and surgical recurrence (re-resection). RESULTS: A total of 341 CD patients were included. In 125 out of 341 (37%) patients, the ileal blind loop was described in the endoscopy reports. IBLI was reported in 43 of 341 (13%) patients. Start or step-up drug therapy was initiated in 10 of 32 (31%) IBLI patients with abdominal symptoms within a median of 0.9 months [interquartile range (IQR) 0.7-1.4] after ileocolonoscopy. Endoscopic recurrence occurred in 4 out of 38 (11%) IBLI patients without re-resection, within a median of 12.4 months (IQR 6.8-13.3). Intestinal re-res

    Outcome squares integrating efficacy and safety, as applied to functioning pituitary adenoma surgery

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    Context: Transsphenoidal surgery is standard care in the treatment of hormone-secreting pituitary adenomas. Current clinician-reported surgical outcome measures are one-dimensional, typically focusing primarily on complete or partial resection, and secondarily on complication rates. However, outcomes are best reflected by the delicate balance of efficacy and complications at patient level.Objective: This study proposes a novel way to classify and report outcomes, integrating efficacy and safety at the patient level.Methods: Retrospective chart review of all pure endoscopic transsphenoidal surgical procedures for acromegaly, Cushing's disease, and prolactinoma between 2010 and 2018 in a single tertiary referral center. We present our results in a classic (remission and complications separate) and in a novel outcome square integrating both outcomes, focusing on intended and adverse effects (long-term complications). This resulted in 4 outcome groups, ranging from good to poor. We use this approach to present these outcomes for several subgroups.Results: A total of 198 surgical procedures were included (44 reoperations). Remission was achieved in 127 operations (64%). Good outcome was observed after 121 (61%), and poor outcome after 6 (3%) operations. When intended effect of surgery was applied (instead of remission), good outcome as intended was achieved after 148 of 198 surgeries (75%) and poor outcome after 4 (2%).Conclusion: Quality of a surgical intervention can be presented in 4 simple categories, integrating both efficacy and safety with flexibility to adapt to the individualized situation at patient, disease, and surgical strategy and to the outcome of interest.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

    Energy and Flux Measurements of Ultra-High Energy Cosmic Rays Observed During the First ANITA Flight

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    The first flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment recorded 16 radio signals that were emitted by cosmic-ray induced air showers. For 14 of these events, this radiation was reflected from the ice. The dominant contribution to the radiation from the deflection of positrons and electrons in the geomagnetic field, which is beamed in the direction of motion of the air shower. This radiation is reflected from the ice and subsequently detected by the ANITA experiment at a flight altitude of 36km. In this paper, we estimate the energy of the 14 individual events and find that the mean energy of the cosmic-ray sample is 2.9 EeV. By simulating the ANITA flight, we calculate its exposure for ultra-high energy cosmic rays. We estimate for the first time the cosmic-ray flux derived only from radio observations. In addition, we find that the Monte Carlo simulation of the ANITA data set is in agreement with the total number of observed events and with the properties of those events.Comment: Added more explanation of the experimental setup and textual improvement

    Alpha scattering and capture reactions in the A = 7 system at low energies

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    Differential cross sections for 3^3He-α\alpha scattering were measured in the energy range up to 3 MeV. These data together with other available experimental results for 3^3He +α+ \alpha and 3^3H +α+ \alpha scattering were analyzed in the framework of the optical model using double-folded potentials. The optical potentials obtained were used to calculate the astrophysical S-factors of the capture reactions 3^3He(α,Îł)7(\alpha,\gamma)^7Be and 3^3H(α,Îł)7(\alpha,\gamma)^7Li, and the branching ratios for the transitions into the two final 7^7Be and 7^7Li bound states, respectively. For 3^3He(α,Îł)7(\alpha,\gamma)^7Be excellent agreement between calculated and experimental data is obtained. For 3^3H(α,Îł)7(\alpha,\gamma)^7Li a S(0)S(0) value has been found which is a factor of about 1.5 larger than the adopted value. For both capture reactions a similar branching ratio of R=σ(Îł1)/σ(Îł0)≈0.43R = \sigma(\gamma_1)/\sigma(\gamma_0) \approx 0.43 has been obtained.Comment: submitted to Phys.Rev.C, 34 pages, figures available from one of the authors, LaTeX with RevTeX, IK-TUW-Preprint 930540
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