Evaluation of earlier versus later dietary management in long-chain 3-hydroxyacyl-CoA dehydrogenase or mitochondrial trifunctional protein deficiency::a systematic review

Background: Mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiencies are rare fatty acid β-oxidation disorders. Without dietary management the conditions are life-threatening. We conducted a systematic review to investigate whether pre-symptomatic dietary management following newborn screening provides better outcomes than treatment following symptomatic detection. Methods: We searched Web of Science, Medline, Pre-Medline, Embase and the Cochrane Library up to 23rd April 2018. Two reviewers independently screened titles, abstracts and full texts for eligibility and quality appraised the studies. Data extraction was performed by one reviewer and checked by another. Results: We included 13 articles out of 7483 unique records. The 13 articles reported on 11 patient groups, including 174 people with LCHAD deficiency, 18 people with MTP deficiency and 12 people with undifferentiated LCHAD/MTP deficiency. Study quality was moderate to weak in all studies. Included studies suggested fewer heart and liver problems in screen-detected patients, but inconsistent results for mortality. Follow up analyses compared long-term outcomes of (1) pre-symptomatically versus symptomatically treated patients, (2) screened versus unscreened patients, and (3) asymptomatic screen-detected, symptomatic screen-detected, and clinically diagnosed patients in each study. For follow up analyses 1 and 2, we found few statistically significant differences in the long-term outcomes. For follow up analysis 3 we found a significant difference for only one comparison, in the incidence of cardiomyopathy between the three groups. Conclusions: There is some evidence that dietary management following screen-detection might be associated with a lower incidence of some LCHAD and MTP deficiency-related complications. However, the evidence base is limited by small study sizes, quality issues and risk of confounding. An internationally collaborative research effort is needed to fully examine the risks and the benefits to pre-emptive dietary management with particular attention paid to disease severity and treatment group.</p

Nuclear Charge Radius of 12^{12}Be

The nuclear charge radius of $^{12}$Be was precisely determined using the technique of collinear laser spectroscopy on the $2s_{1/2}\rightarrow 2p_{1/2, 3/2}$ transition in the Be$^{+}$ ion. The mean square charge radius increases from $^{10}$Be to $^{12}$Be by \delta ^{10,12} = 0.69(5) \fm^{2} compared to \delta ^{10,11} = 0.49(5) \fm^{2} for the one-neutron halo isotope $^{11}$Be. Calculations in the fermionic molecular dynamics approach show a strong sensitivity of the charge radius to the structure of $^{12}$Be. The experimental charge radius is consistent with a breakdown of the N=8 shell closure.Comment: 5 pages, 3 figure

Test of Time Dilation Using Stored Li+ Ions as Clocks at Relativistic Speed

We present the concluding result from an Ives-Stilwell-type time dilation experiment using 7Li+ ions confined at a velocity of beta = v/c = 0.338 in the storage ring ESR at Darmstadt. A Lambda-type three-level system within the hyperfine structure of the 7Li+ triplet S1-P2 line is driven by two laser beams aligned parallel and antiparallel relative to the ion beam. The lasers' Doppler shifted frequencies required for resonance are measured with an accuracy of < 4 ppb using optical-optical double resonance spectroscopy. This allows us to verify the Special Relativity relation between the time dilation factor gamma and the velocity beta to within 2.3 ppb at this velocity. The result, which is singled out by a high boost velocity beta, is also interpreted within Lorentz Invariance violating test theories

Collinear laser spectroscopy of atomic cadmium

Hyperfine structure $A$ and $B$ factors of the atomic $5s\,5p\,\; ^3\rm{P}_2 \rightarrow 5s\,6s\,\; ^3\rm{S}_1$ transition are determined from collinear laser spectroscopy data of $^{107-123}$Cd and $^{111m-123m}$Cd. Nuclear magnetic moments and electric quadrupole moments are extracted using reference dipole moments and calculated electric field gradients, respectively. The hyperfine structure anomaly for isotopes with $s_{1/2}$ and $d_{5/2}$ nuclear ground states and isomeric $h_{11/2}$ states is evaluated and a linear relationship is observed for all nuclear states except $s_{1/2}$. This corresponds to the Moskowitz-Lombardi rule that was established in the mercury region of the nuclear chart but in the case of cadmium the slope is distinctively smaller than for mercury. In total four atomic and ionic levels were analyzed and all of them exhibit a similar behaviour. The electric field gradient for the atomic $5s\,5p\,\; ^3\mathrm{P}_2$ level is derived from multi-configuration Dirac-Hartree-Fock calculations in order to evaluate the spectroscopic nuclear quadrupole moments. The results are consistent with those obtained in an ionic transition and based on a similar calculation.Comment: 12 pages, 5 figure

Upgrade of the ultracold neutron source at the pulsed reactor TRIGA Mainz

The performance of the upgraded solid deuterium ultracold neutron source at the pulsed reactor TRIGA Mainz is described. The current configuration stage comprises the installation of a He liquefier to run UCN experiments over long-term periods, the use of stainless steel neutron guides with improved transmission as well as sputter-coated non-magnetic $^{58}$NiMo alloy at the inside walls of the thermal bridge and the converter cup. The UCN yield was measured in a `standard' UCN storage bottle (stainless steel) with a volume of 32 litres outside the biological shield at the experimental area yielding UCN densities of 8.5 /cm$^3$; an increase by a factor of 3.5 compared to the former setup. The measured UCN storage curve is in good agreement with the predictions from a Monte Carlo simulation developed to model the source. The growth and formation of the solid deuterium converter during freeze-out are affected by the ortho/para ratio of the H$_2$ premoderator.Comment: 12 pages, 7 figure

Observation of the hyperfine transition in lithium-like Bismuth 209Bi80+^{209}\text{Bi}^{80+}: Towards a test of QED in strong magnetic fields

We performed a laser spectroscopic determination of the $2s$ hyperfine splitting (HFS) of Li-like $^{209}\text{Bi}^{80+}$ and repeated the measurement of the $1s$ HFS of H-like $^{209}\text{Bi}^{82+}$. Both ion species were subsequently stored in the Experimental Storage Ring at the GSI Helmholtzzentrum f\"ur Schwerionenforschung Darmstadt and cooled with an electron cooler at a velocity of $\approx 0.71\,c$. Pulsed laser excitation of the $M1$ hyperfine-transition was performed in anticollinear and collinear geometry for $\text{Bi}^{82+}$ and $\text{Bi}^{80+}$, respectively, and observed by fluorescence detection. We obtain $\Delta E^{(1s)}= 5086.3(11)\,\textrm{meV}$ for $\text{Bi}^{82+}$, different from the literature value, and $\Delta E^{(2s)}= 797.50(18)\,\textrm{meV}$ for $\text{Bi}^{80+}$. These values provide experimental evidence that a specific difference between the two splitting energies can be used to test QED calculations in the strongest static magnetic fields available in the laboratory independent of nuclear structure effects. The experimental result is in excellent agreement with the theoretical prediction and confirms the sum of the Dirac term and the relativistic interelectronic-interaction correction at a level of 0.5% confirming the importance of accounting for the Breit interaction.Comment: 5 pages, 2 figure

Newborn Screening for Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase and Mitochondrial Trifunctional Protein Deficiencies Using Acylcarnitines Measurement in Dried Blood Spots—A Systematic Review of Test Accuracy

Background: Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies are rare autosomal recessive fatty acid β-oxidation disorders. Their clinical presentations are variable, and premature death is common. They are included in newborn blood spot screening programs in many countries around the world. The current process of screening, through the measurement of acylcarnitines (a metabolic by-product) in dried blood spots with tandem mass spectrometry, is subject to uncertainty regarding test accuracy.Methods: We conducted a systematic review of literature published up to 19th June 2018. We included studies that investigated newborn screening for LCHAD or MTP deficiencies by tandem mass spectrometry of acylcarnitines in dried blood spots. The reference standards were urine organic acids, blood acylcarnitine profiles, enzyme analysis in cultured fibroblasts or lymphocytes, mutation analysis, or at least 10-year follow-up. The outcomes of interest were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Assessment of titles, abstracts, and full-text papers and quality appraisal were carried out independently by two reviewers. One reviewer extracted study data. This was checked by a second reviewer.Results: Ten studies provided data on test accuracy. LCHAD or MTP deficiencies were identified in 23 babies. No cases of LCHAD/MTP deficiencies were identified in four studies. PPV ranged from 0% (zero true positives and 28 false positives from 276,565 babies screened) to 100% (13 true positives and zero false positives from 2,037,824 babies screened). Sensitivity, specificity, and NPV could not be calculated as there was no systematic follow-up of babies who screened negative.Conclusions: Test accuracy estimates of screening for LCHAD and MTP deficiencies with tandem mass spectrometry measurement of acylcarnitines in dried blood were variable in terms of PPVs. Screening methods (including markers and thresholds) varied between studies, and sensitivity, specificity, and NPVs are unknown

Effect of Acute Beetroot Juice Supplementation on Power Output during Resistance Exercise in Resistance-Trained Women

Dietary nitrate supplementation has been reported to enhance explosive-type movements, but our understanding of the ergogenic potential in resistance exercise and women remains understudied. PURPOSE: To investigate if dietary nitrate, provided as nitrate-rich beetroot juice (BR), improved resistance exercise performance compared to nitrate-depleted beetroot juice (PL) in resistance-trained women. METHODS: Eighteen resistance-trained women were assigned in a randomized, double-blind, crossover design to consume PL (0.10 mmol nitrate) and BR (6 mmol of nitrate) 2.5 h prior to performing barbell back squats and bench press at 55% one-repetition max (1RM), 60%1RM, and 65%1RM. Power and velocity were measured via a linear transducer during exercise. All visits were performed during the early follicular phase. RESULTS: A subset of data has been obtained (n=8) and thus our results remain blinded. Squat peak power was recorded in Condition A (55%1RM 690 ± 173 W, 60%1RM 714 ± 187 W, 65%1RM 779 ± 197 W) and Condition B (55%1RM 717 ± 195 W, 60%1RM 749 ± 189 W, 65%1RM 823 ± 183 W). Squat mean power was recorded in Condition A (55%1RM 310 ± 62 W, 60%1RM 318 ± 65 W, 65%1RM 329 ± 61 W) and Condition B (55%1RM 308 ± 61 W, 60%1RM 322 ± 59 W, 65%1RM 315 ± 72 W). Bench peak power was recorded in Condition A (55%1RM 305 ± 108.93 W, 60%1RM 292 ± 100 W, 65%1RM 293 ± 84 W) and Condition B (55%1RM 310 ± 107 W, 60%1RM 302 ± 91 W, 65%1RM 302 ± 90 W). Bench mean power was recorded in Condition A (55%1RM 181 ± 55 W, 60%1RM 185 ± 52 W, 65%1RM 182 ± 50 W) and Condition B (55%1RM 178 ± 46 W, 60%1RM 190 ± 51 W, 65%1RM 182 ± 50 W). CONCLUSION: These data provide insight for dietary nitrate as an ergogenic aid to enhance resistance exercise performance in resistance-trained women

Effects Of Acute And Multi-day Beetroot Juice Supplementation On Power And Velocity Of NCAA Division I Baseball Players: Pilot Data

While dietary nitrate supplementation can enhance type II fiber contractility, the ergogenic potential of nitrate is relatively unexplored in explosive-type modalities and populations such as resistance exercise and power-based athletes. PURPOSE: To investigate if acute and chronic nitrate ingestion, provided as nitrate-rich beetroot juice (BR), improves resistance exercise performance nitrate-depleted beetroot juice placebo (PL) in male National Collegiate Athletic Association (NCAA) Division I baseball players. METHODS: Eighteen male collegiate baseball athletes (NCAA Division I), who are position players (i.e., not pitchers) were randomized in a double-blind, crossover design to consume 1) PL (negligible nitrate) and 2) BR (~6 mmol of nitrate) 2.5 h prior to performing exercise. Peak and mean power and velocity, and the within- and between-day coefficient of variation (CV%), were measured using a linear transducer during barbell squats and bench press performed at 55% one-repetition maximum (1RM), 60%1RM, and 65%1RM. RESULTS: Pilot data have been collected (n=4). All CV% data for peak power, mean power, peak velocity, and mean velocity wereCONCLUSION: Data collection is ongoing for n=18. These data will contribute to informing dietary nitrate supplementation guidelines in a population-specific manner and provide insight to the efficacy of nitrate on resistance exercise performance in power-based athletes