Closed-cycle, low-vibration 4 K cryostat for ion traps and other applications

In-vacuo cryogenic environments are ideal for applications requiring both low temperatures and extremely low particle densities. This enables reaching long storage and coherence times for example in ion traps, essential requirements for experiments with highly charged ions, quantum computation, and optical clocks. We have developed a novel cryostat continuously refrigerated with a pulse-tube cryocooler and providing the lowest vibration level reported for such a closed-cycle system with 1 W cooling power for a <5 K experiment. A decoupling system suppresses vibrations from the cryocooler by three orders of magnitude down to a level of 10 nm peak amplitudes in the horizontal plane. Heat loads of about 40 W (at 45 K) and 1 W (at 4 K) are transferred from an experimental chamber, mounted on an optical table, to the cryocooler through a vacuum-insulated massive 120 kg inertial copper pendulum. The 1.4 m long pendulum allows installation of the cryocooler in a separate, acoustically isolated machine room. In the laser laboratory, we measured the residual vibrations using an interferometric setup. The positioning of the 4 K elements is reproduced to better than a few micrometer after a full thermal cycle to room temperature. Extreme high vacuum on the $10^{-15}$ mbar level is achieved. In collaboration with the Max-Planck-Intitut f\"ur Kernphysik (MPIK), such a setup is now in operation at the Physikalisch-Technische Bundesanstalt (PTB) for a next-generation optical clock experiment using highly charged ions

Impact of treatment planning target volumen (PTV) size on radiation induced diarrhoea following selenium supplementation in gynecologic radiation oncology - a subgroup analysis of a multicenter, phase III trial

Background: In a previous analysis (Int J Radiat Oncol Biol Phys 70:828-835,2010), we assessed whether an adjuvant supplementation with selenium (Se) improves Se status and reduces the radiation-induced side-effects of patients treated by adjuvant radiotherapy (RT) for cervical and uterine cancer. Now, a potential relation between the planning target volume (PTV) of the RT and the Se effect concerning radiation induced diarrhoea was evaluated in detail. Methods: Whole blood Se concentrations had been measured in patients with cervical (n=11) and uterine cancer (n=70) after surgical treatment, during, and at the end of RT. Patients with initial Se concentrations of less than 84 μg/l were categorized as Se-deficient and randomized before RT to receive Se (as sodium selenite) per os on the days of RT, or to receive no supplement during RT. Diarrhoea was graded according to the Common Toxicity Criteria system (CTC, Version 2a). The evaluation of the PTV of the RT was ascertained with the help of a specialised computer-assisted treatment planning software used for radiation planning procedure. Results: A total of 81 patients had been randomized for the initial supplementation study, 39 of which received Se [selenium group, SeG] and 42 serving as controls [control group, CG]. Mean Se levels did not differ between SeG and CG upon study initiation, but were significantly higher in the SeG compared to the CG at the end of RT. The actuarial incidence of at least CTC 2 radiation induced diarrhoea in the SeG was 20.5% compared to 44.5% in the CG (p=0.04). The median PTV in both groups was 1302 ml (916–4608). With a PTV of 1302 ml (n=40) the actuarial incidence of at least CTC 2 diarrhoea in the SeG was 19.1% (4 of 21 patients) versus 52.6% (10 of 19 patients) in the CG (p=0.046). Conclusions: Se supplementation during RT was effective to improve blood Se status in Se-deficient cervical and uterine cancer patients, and reduces episodes and severity of RT-induced diarrhoea. This effect was most pronounced and significant in patients with large PTV (> 1302 ml)

Algorithmic Ground-state Cooling of Weakly-Coupled Oscillators using Quantum Logic

Most ions lack the fast, cycling transitions that are necessary for direct laser cooling. In most cases, they can still be cooled sympathetically through their Coulomb interaction with a second, coolable ion species confined in the same potential. If the charge-to-mass ratios of the two ion types are too mismatched, the cooling of certain motional degrees of freedom becomes difficult. This limits both the achievable fidelity of quantum gates and the spectroscopic accuracy. Here we introduce a novel algorithmic cooling protocol for transferring phonons from poorly- to efficiently-cooled modes. We demonstrate it experimentally by simultaneously bringing two motional modes of a Be$^{+}$-Ar$^{13+}$ mixed Coulomb crystal close to their zero-point energies, despite the weak coupling between the ions. We reach the lowest temperature reported for a highly charged ion, with a residual temperature of only $T\lesssim200~\mathrm{\mu K}$ in each of the two modes, corresponding to a residual mean motional phonon number of $\langle n \rangle \lesssim 0.4$. Combined with the lowest observed electric field noise in a radiofrequency ion trap, these values enable an optical clock based on a highly charged ion with fractional systematic uncertainty below the $10^{-18}$ level. Our scheme is also applicable to (anti-)protons, molecular ions, macroscopic charged particles, and other highly charged ion species, enabling reliable preparation of their motional quantum ground states in traps

Sapucaia nut (Lecythis pisonis Cambess) and its by-products: a promising and underutilized source of bioactive compounds. Part II: phenolic compounds profile.

In this study, the profile of the bioactive compounds of sapucaia nut (Lecythis pisonis Cambess) and its byproducts have been investigated. The phenolic profile by LC-ESI-MS/MS, the total phenolic content, the condensed tannins and the antioxidant activity of the sapucaia nut and shell were determined. 14 phenolic compounds were identified in the sapucaia nut extract, primarily phenolic acids and flavonoids. Catechin, epicatechin, myricetin, ellagic acid and ferulic acid presented significant correlation to the antioxidant activity. The sapucaia shell contained 22 phenolic compounds, 13 of which were quantified. The sapucaia shell extract showed a high content of total phenolic compounds, a high condensed tannins content, and high antioxidant activity. The higher antioxidant activity of the shell can be associated with a higher content of phenolics. Overall, it can be concluded that the sapucaia nut is a raw material rich in phenolic compounds that present high antioxidant activity. The nuts and the cake may be used as a promising raw material for the food industry, while the shells could be an alternative source of natural antioxidants. Further use in the cosmetics and pharmaceutical industry may also be envisaged. 1. Introduction Lecythis pisonis

Fractionation of forage legumes using a screw press

Technical advances in fractionation and biorefining of grassland crops may allow farmers to produce feed for monogastrics and ruminants. The objective of the present work was to quantify yields of juice and pulp from different forage legumes. We established field trials with plots of monocultures of lucerne, red clover and alsike clover in Röbäcksdalen, Sweden and Tingvoll, Norway in 2018. We harvested the crops three times in Röbäcksdalen and four times in Tingvoll in 2019 and used a twin-gear screw press to separate juice and pulp. Red clover had the highest total yields, with higher yields in Sweden than Norway. In Norway, the average dry matter (DM) content in juice was 10.7% and in pulp 33.0%. Juice accounted for 43.8% of DM on average. Lucerne had lower juice DM proportion than the clover species. No effects of harvest number on juice DM proportion were found. These preliminary results indicate that clover species yield more juice and less pulp, compared with lucerne. Quality analyses will be carried out to estimate feed value of both fractions

Serum CA19-9 response as a surrogate for clinical outcome in patients receiving fixed-dose rate gemcitabine for advanced pancreatic cancer

The use of serial serum measurements of the carbohydrate antigen 19-9 (CA19-9) to guide treatment decisions and serve as a surrogate end point in clinical trial design requires further validation. We investigated whether CA19-9 decline represents an accurate surrogate for survival and time to treatment failure (TTF) in a cohort of 76 patients with advanced pancreatic cancer receiving fixed-dose rate gemcitabine in three separate studies. Statistically significant correlations between percentage CA19-9 decline and both overall survival and TTF were found, with median survival ranging from 12.0 months for patients with the greatest degree of biomarker decline (>75%) compared with 4.3 months in those whose CA19-9 did not decline during therapy (P<0.001). Using specific thresholds, patients with ⩾25% decline in CA19-9 during treatment had significantly better outcomes than those who did not (median survival and TTF of 9.6 and 4.6 months vs 4.4 and 1.5 months; P<0.001). Similar results were seen using both 50 and 75% as cutoff points. We conclude that serial CA19-9 measurements correlate well with clinical outcomes in this patient population, and that decline in this biomarker should be entertained for possible use as a surrogate end point in clinical trials for the selection of new treatments in this disease

Sensitivity to New Physics of Isotope Shift Studies using the Coronal Lines of Highly Charged Calcium Ions

Promising searches for new physics beyond the current Standard Model (SM) of particle physics are feasible through isotope-shift spectroscopy, which is sensitive to a hypothetical fifth force between the neutrons of the nucleus and the electrons of the shell. Such an interaction would be mediated by a new particle which could in principle be associated with dark matter. In so-called King plots, the mass-scaled frequency shifts of two optical transitions are plotted against each other for a series of isotopes. Subtle deviations from the expected linearity could reveal such a fifth force. Here, we study experimentally and theoretically six transitions in highly charged ions of Ca, an element with five stable isotopes of zero nuclear spin. Some of the transitions are suitable for upcoming high-precision coherent laser spectroscopy and optical clocks. Our results provide a sufficient number of clock transitions for -- in combination with those of singly charged Ca$^+$ -- application of the generalized King plot method. This will allow future high-precision measurements to remove higher-order SM-related nonlinearities and open a new door to yet more sensitive searches for unknown forces and particles

Importance of Magnesium Status in COVID-19

A large amount of published research points to the interesting concept (hypothesis) that magnesium (Mg) status may have relevance for the outcome of COVID-19 and that Mg could be protective during the COVID disease course. As an essential element, Mg plays basic biochemical, cellular, and physiological roles required for cardiovascular, immunological, respiratory, and neurological functions. Both low serum and dietary Mg have been associated with the severity of COVID-19 outcomes, including mortality; both are also associated with COVID-19 risk factors such as older age, obesity, type 2 diabetes, kidney disease, cardiovascular disease, hypertension, and asthma. In addition, populations with high rates of COVID-19 mortality and hospitalization tend to consume diets high in modern processed foods, which are generally low in Mg. In this review, we review the research to describe and consider the possible impact of Mg and Mg status on COVID-19 showing that (1) serum Mg between 2.19 and 2.26 mg/dL and dietary Mg intakes &gt; 329 mg/day could be protective during the disease course and (2) inhaled Mg may improve oxygenation of hypoxic COVID-19 patients. In spite of such promise, oral Mg for COVID-19 has thus far been studied only in combination with other nutrients. Mg deficiency is involved in the occurrence and aggravation of neuropsychiatric complications of COVID-19, including memory loss, cognition, loss of taste and smell, ataxia, confusion, dizziness, and headache. Potential of zinc and/or Mg as useful for increasing drug therapy effectiveness or reducing adverse effect of anti-COVID-19 drugs is reviewed. Oral Mg trials of patients with COVID-19 are warranted