115 research outputs found

    Experimental Demonstration of Superradiant Amplification of Ultra-Short Laser Pulses in a Plasma

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    A novel amplifications scheme for 20-30-fs laser pulses has been demonstrated. The signal pulses are amplified in a plasma by few picosecond long, counterpropagating pump pulses. The signal and pump pulses arrange the plasma electrons to a density grating reflecting the pump light back into the signal pulse. In the superradiant regime, the plasma electrons scatter the pump pulse coherently. By an intrinsic mechanism a further shortening of the signal pulse to less than 10 fs is possible. The experiment was set up at the "Max-Planck-Institut fĂŒr Quantenoptik", using the ATLAS laser system as source for the pump and input signal pulses. Both a regime with pump and signal pulse at the same initial wavelength and with a input signal shifted towards longer wavelengths with respect to the pump pulse were investigated. The unshifted signal pulse showed some initial amplification but further amplification was frustrated by the onset of Brillouin scattering. The superradiant regime was observed for the red-shifted input signal pulse. It is proven by 20 times energy amplification, the spectral broadening indicating the pulse shortening, and the breakup of the 80-fs long signal pulse caused by the very mechanism responsible also for the pulse shortening. An outlook is given for improved amplification in non-planar geometries

    Boost me: prevalence and reasons for the use of stimulant containing pre workout supplements among fitness studio visitors in Mainz (Germany)

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    The rapidly increasing interest in fitness related sports over the past few years has been accompanied by a booming industry of nutritional supplements. Many of these substances have unproven benefits and are even potentially harmful to the user. The aim of this study was to determine the prevalence and reasons for nutritional supplement (NS) use among fitness studio visitors in Mainz (Germany), emphasizing new multi-ingredient based supplements such as pre workout boosters (PWBs). Some of the PWBs contain stimulants such as DMAA, N,α-DEPEA, DMAE and DMBA with so far unknown risks, harms and benefits. Four-Hundred and Ninety Two participants in 13 fitness studios completed a questionnaire on the use of nutritional supplements. Descriptive statistics and chi-square tests were used to examine differences in supplement use regarding training- and intake-reasons. About 57.0% of the participants reported the use of NS during the last 4 weeks. The all-time prevalence of creatine use was 28.7%, whereas 12.2% of the participants stated creatine use during the past 4 weeks. The all-time prevalence of PWB intake was 25.8%, whereas the last month prevalence was 11.8%. Among the group of PWB users, 20.5% stated to search specifically for substances such as DMAA, N,α-DEPEA, DMAE or DMBA. Logistic regression analysis showed positive relations between creatine use and the predictor variables gender, strength training and bodybuilding, as well as the stated exercisers' training reasons to increase physical- and sports-performance, and quality of life. PWB consumption was related to the variables gender, training frequency, and the reason for sports performance enhancement. Specific ingredient focus was related to the predictor variables competition participation and increase of mental performance. The results of the study show a high prevalence of PWB consumption among fitness studios visitors, which is comparable with creatine use. The predicting variables for consumption seem to be slightly different between the supplements, especially if the users are searching for stimulating agents. The current findings help to create preliminary consumption patterns and can help to identify potential endangered fitness studio visitors for prevention and risk communication, especially for PWBs

    Lock-in detection for pulsed electrically detected magnetic resonance

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    We show that in pulsed electrically detected magnetic resonance (pEDMR) signal modulation in combination with a lock-in detection scheme can reduce the low-frequency noise level by one order of magnitude and in addition removes the microwave-induced non-resonant background. This is exemplarily demonstrated for spin-echo measurements in phosphorus-doped Silicon. The modulation of the signal is achieved by cycling the phase of the projection pulse used in pEDMR for the read-out of the spin state.Comment: 4 pages, 2 figure

    Boost Me: Prevalence and Reasons for the Use of Stimulant Containing Pre Workout Supplements Among Fitness Studio Visitors in Mainz (Germany)

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    The rapidly increasing interest in fitness related sports over the past few years has been accompanied by a booming industry of nutritional supplements. Many of these substances have unproven benefits and are even potentially harmful to the user. The aim of this study was to determine the prevalence and reasons for nutritional supplement (NS) use among fitness studio visitors in Mainz (Germany), emphasizing new multi-ingredient based supplements such as pre workout boosters (PWBs). Some of the PWBs contain stimulants such as DMAA, N,α-DEPEA, DMAE and DMBA with so far unknown risks, harms and benefits. Four-Hundred and Ninety Two participants in 13 fitness studios completed a questionnaire on the use of nutritional supplements. Descriptive statistics and chi-square tests were used to examine differences in supplement use regarding training- and intake-reasons. About 57.0% of the participants reported the use of NS during the last 4 weeks. The all-time prevalence of creatine use was 28.7%, whereas 12.2% of the participants stated creatine use during the past 4 weeks. The all-time prevalence of PWB intake was 25.8%, whereas the last month prevalence was 11.8%. Among the group of PWB users, 20.5% stated to search specifically for substances such as DMAA, N,α-DEPEA, DMAE or DMBA. Logistic regression analysis showed positive relations between creatine use and the predictor variables gender, strength training and bodybuilding, as well as the stated exercisers' training reasons to increase physical- and sports-performance, and quality of life. PWB consumption was related to the variables gender, training frequency, and the reason for sports performance enhancement. Specific ingredient focus was related to the predictor variables competition participation and increase of mental performance. The results of the study show a high prevalence of PWB consumption among fitness studios visitors, which is comparable with creatine use. The predicting variables for consumption seem to be slightly different between the supplements, especially if the users are searching for stimulating agents. The current findings help to create preliminary consumption patterns and can help to identify potential endangered fitness studio visitors for prevention and risk communication, especially for PWBs

    IL‐13, periostin and dipeptidyl‐peptidase‐4 reveal endotype‐phenotype associations in atopic dermatitis

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    Background: The heterogeneous (endo)phenotypes of atopic dermatitis (AD) require precision medicine. Currently, systemic therapy is recommended to patients with an Eczema Area and Severity Index (EASI) ≄ 16. Previous studies have demonstrated an improved treatment response to the anti‐interleukin (IL)‐13 antibody tralokinumab in AD subgroups with elevated levels of the IL‐13‐related biomarkers dipeptidyl‐peptidase (DPP)‐4 and periostin. Methods: Herein, 373 AD patients aged ≄12 years were stratified by IL‐13high^{high}, periostinhigh^{high} and DPP‐4high^{high} endotypes using cross‐sectional data from the ProRaD cohort Bonn. “High” was defined as >80th quantile of 47 non‐atopic controls. We analyzed endotype‐phenotype associations using machine‐learning gradient boosting compared to logistic regression. Results: Atopic dermatitis severity and eosinophils correlated with IL‐13 and periostin levels. Correlations of IL‐13 with EASI were stronger in patients with increased (rs = 0.482) than with normal (rs = 0.342) periostin levels. We identified eosinophilia >6% and an EASI range of 5.5–17 dependent on the biomarker combination to be associated with increasing probabilities of biomarkerhigh^{high} endotypes. Also patients with mild‐to‐low‐moderate severity (EASI < 16) featured increased biomarkers (IL‐13high^{high}: 41%, periostinhigh^{high}: 48.4%, DPP‐4high^{high}: 22.3%). Herthoge sign (adjusted Odds Ratio (aOR) = 1.89, 95% Confidence Interval (CI) [1.14–3.14]) and maternal allergic rhinitis (aOR = 2.79–4.47) increased the probability of an IL‐13high^{high}‐endotype, “dirty neck” (aOR = 2.83 [1.32–6.07]), orbital darkening (aOR = 2.43 [1.08–5.50]), keratosis pilaris (aOR = 2.21 [1.1–4.42]) and perleche (aOR = 3.44 [1.72–6.86]) of a DPP‐4high^{high}‐endotype. Conclusions: A substantial proportion of patients with EASI < 16 featured high biomarker levels suggesting systemic impact of skin inflammation already below the current cut‐off for systemic therapy. Our findings facilitate the identification of patients with distinct endotypes potentially linked to response to IL‐13‐targeted therapy

    Story Possibilities in Religious Studies at USD

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    The etiology of overweight and obesity is a mixture of genetic determinants, environmental factors, and health behaviors. Especially intra- and interpersonal inactive behaviors, here termed convenience, seems to play an important role. The objective was to develop and validate the Convenience Behavior Questionnaire (CBQ) to assess convenience-related items and their association with overweight and obesity in a large population. A sample of 1233 subjects aged 18–82 years from six population groups took part in a self-administered questionnaire. Test-retest reliability was estimated and the independent association between convenience-related items and overweight and obesity was investigated. Principal component analysis revealed three factors (avoidance behaviors, social interaction behaviors and domestic environmental factors) which explained 43.4% of the variance contributing to the CBQ. Cronbach's α ranged from 0.80–0.89. Test-retest reliability using intra-class correlation was acceptable ≄ 0.70. Forward stepwise logistic regression analysis, including gender, education level, age and TV viewing on weekends showed a positive relation of convenience behavior and overweight (OR: 1.40; 95% CI: 1.01–1.96; P = 0.048), while physical activity status was not significantly associated with overweight (OR: 1.09; 95% CI: 0.77–1.54; P = 0.629). The CBQ seems to be a reliable tool which considers non-traditional behaviors related to overweight development. Interestingly our findings revealed a better relationship between convenience-related behavior with overweight and obesity than the habitual physical activity score

    Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood

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    Background: Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls. Methods: We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, ZĂŒrich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; ≄2 to 6; ≄7 to 11; ≄12 to 18); adult-onset ≄18 years: 23.6% (subsets: ≄18 to 40; ≄41 to 60; ≄61) and 167 controls (91 atopic, 76 non-atopic)). Results: We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controlsnon−atopic^{non-atopic} , aOR = 4.03 [1.20-13.45] vs. controlsatopic^{atopic} ). Conjunctivitis showed a negative association versus controlsatopic^{atopic} (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controlsatopic^{atopic}. Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset ≄61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters. Conclusions: The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors
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