Long range transport of ultra cold atoms in a far-detuned 1D optical lattice

We present a novel method to transport ultra cold atoms in a focused optical lattice over macroscopic distances of many Rayleigh ranges. With this method ultra cold atoms were transported over 5 cm in 250 ms without significant atom loss or heating. By translating the interference pattern together with the beam geometry the trap parameters are maintained over the full transport range. Thus, the presented method is well suited for tightly focused optical lattices that have sufficient trap depth only close to the focus. Tight focusing is usually required for far-detuned optical traps or traps that require high laser intensity for other reasons. The transport time is short and thus compatible with the operation of an optical lattice clock in which atoms are probed in a well designed environment spatially separated from the preparation and detection region.Comment: 14 pages, 6 figure

Accurate spectroscopy of Sr atoms

We report the frequency measurement with an accuracy in the 100 kHz range of several optical transitions of atomic Sr : $^1S_0- ^3P_1$ at 689 nm, $^3P_1- ^3S_1$ at 688 nm and $^3P_0- ^3S_1$ at 679 nm. Measurements are performed with a frequency chain based on a femtosecond laser referenced to primary frequency standards. They allowed the indirect determination with a 70 kHz uncertainty of the frequency of the doubly forbidden 5s^2^1S_0- 5s5p^3P_0 transition of $^{87}$Sr at 698 nm and in a second step its direct observation. Frequency measurements are performed for $^{88}$Sr and $^{87}$Sr, allowing the determination of $^3P_0$, $^3P_1$ and $^3S_1$ isotope shifts, as well as the $^3S_1$ hyperfine constants.Comment: 12 pages, 16 figure

Supplementations of industrial multichamber parenteral nutrition bags in critically ill children: safety of the practice

Parenteral nutrition (PN) is sometimes required in critically ill children because of contraindication or intolerance to full enteral nutrition. European guidelines recommend favoring multichamber bag PN (MCB PN), when possible, for quality purposes and ease of use. The prescribers may adjust the MCB PN through supplementations to better fulfill patient needs. The objective of this study is to investigate the use and supplementations of MCB PN. This observational, single-center, retrospective study was conducted in a pediatric intensive care unit (PICU). We collected prescriptions of MCB PNs and their supplementations added directly into PN bags. A descriptive analysis and a comparison of electrolyte supplementations with the manufacturer's recommendations were undertaken. One hundred thirty-five children (median age 39.2 months [7.0-118.8]) were included, 1449 MCB PNs were administered, and 1652 supplementations were carried out in 736 PN bags. Thirty-two percent of supplementations were vitamins, 32.2% were trace elements, and 35.8% were electrolytes. Around 10% of electrolyte supplementations in PN bags were outside the manufacturer's recommendations. These nonconformities primarily concerned phosphate. This study showed the real-world clinical use of MCB PN in the PICU. Proper attention should be paid to septic risks and physicochemical risks to ensure efficient practice and safety of MCB PN use. [Abstract copyright: © 2022 The Authors. Nutrition in Clinical Practice published by Wiley Periodicals LLC on behalf of American Society for Parenteral and Enteral Nutrition.

Performance of a 229 Thorium solid-state nuclear clock

The 7.8 eV nuclear isomer transition in 229 Thorium has been suggested as an etalon transition in a new type of optical frequency standard. Here we discuss the construction of a "solid-state nuclear clock" from Thorium nuclei implanted into single crystals transparent in the vacuum ultraviolet range. We investigate crystal-induced line shifts and broadening effects for the specific system of Calcium fluoride. At liquid Nitrogen temperatures, the clock performance will be limited by decoherence due to magnetic coupling of the Thorium nucleus to neighboring nuclear moments, ruling out the commonly used Rabi or Ramsey interrogation schemes. We propose a clock stabilization based on counting of flourescence photons and present optimized operation parameters. Taking advantage of the high number of quantum oscillators under continuous interrogation, a fractional instability level of 10^{-19} might be reached within the solid-state approach.Comment: 28 pages, 9 figure

A high stability semiconductor laser system for a 88^{88}Sr-based optical lattice clock

We describe a frequency stabilized diode laser at 698 nm used for high resolution spectroscopy of the 1S0-3P0 strontium clock transition. For the laser stabilization we use state-of-the-art symmetrically suspended optical cavities optimized for very low thermal noise at room temperature. Two-stage frequency stabilization to high finesse optical cavities results in measured laser frequency noise about a factor of three above the cavity thermal noise between 2 Hz and 11 Hz. With this system, we demonstrate high resolution remote spectroscopy on the 88Sr clock transition by transferring the laser output over a phase-noise-compensated 200 m-long fiber link between two separated laboratories. Our dedicated fiber link ensures a transfer of the optical carrier with frequency stability of 7 \cdot 10^{-18} after 100 s integration time, which could enable the observation of the strontium clock transition with an atomic Q of 10^{14}. Furthermore, with an eye towards the development of transportable optical clocks, we investigate how the complete laser system (laser+optics+cavity) can be influenced by environmental disturbances in terms of both short- and long-term frequency stability.Comment: 9 pages, 9 figures, submitted to Appl. Phys.

Anesthetic classification of the physical status and surgical-anesthetic mortality in dogs

A classificação de estado físico ASA (Sociedade Americana de Anestesiologistas) é uma ferramenta importante para a avaliação pré-anestésica do paciente. Assim, é utilizada em diversos estudos por possuir estreita relação com a morbidade e a mortalidade anestésica. Realizou-se tal classificação em 243 pacientes caninos submetidos a procedimentos cirúrgicos em um Hospital Veterinário Universitário. Os resultados obtidos foram os seguintes: ASA I (38; 15,64%), ASA II (53; 21,81%), ASA II emergencial (E) (2; 0,82%), ASA III (78; 32,10%), ASA III E (23; 9,46%), ASA IV (11; 4,53%), ASA IV E (36; 14,81%) e ASA V (2; 0,82%). Verificou-se que a maior parte dos pacientes foram classificados como ASA III (doença sistêmica moderada), o que demonstra que, no serviço analisado, a maioria dos animais submetidos à cirurgia são portadores de enfermidades. A mortalidade foi de 2,46%, com a maioria dos óbitos ocorridos no pós-operatório e em pacientes com emergências. Concluiu-se que, no serviço analisado, os maiores riscos estão relacionados aos pacientes com categorias ASA de maior gravidade, em cirurgias emergenciais e, especialmente, no período pós-operatório.The classification ASA (American Society of Anesthesiologists) is an important tool for assessing a patient's pre anesthetic. Thus, it is used in many studies because it has close relation with anesthetic morbidity and mortality. This classification was performed on 243 canine patients undergoing surgical procedures at the Veterinary Teaching Hospital. The results obtained were as follows: ASA I (38, 15.64%), ASA II (53; 21.81%), ASA II Emergency (E) (2; 0.82%), ASA III (78; 32.10%), ASA III E (23; 9.46%), ASA IV (11; 4.53 %), ASA IV E (36; 14.81%), and ASA V (2; 0.82%). Most patients were ASA III (moderate systemic disease), demonstrating that in the analyzed service the most operated animals are carriers of disease. The mortality rate was 2.46%, with most deaths occurring postoperatively and in patients with an emergency. The greatest risks are related to patients with more severe categories of the classification ASA, in emergency surgery, and especially in the postoperative period

The unstructured linker arms of MutL enable GATC site incision beyond roadblocks during initiation of DNA mismatch repair

DNA mismatch repair (MMR) maintains genome stability through repair of DNA replication errors. In Escherichia coli, initiation of MMR involves recognition of the mismatch by MutS, recruitment of MutL, activation of endonuclease MutH and DNA strand incision at a hemimethylated GATC site. Here, we studied the mechanism of communication that couples mismatch recognition to daughter strand incision. We investigated the effect of catalytically-deficient Cas9 as well as stalled RNA polymerase as roadblocks placed on DNA in between the mismatch and GATC site in ensemble and single molecule nanomanipulation incision assays. The MMR proteins were observed to incise GATC sites beyond a roadblock, albeit with reduced efficiency. This residual incision is completely abolished upon shortening the disordered linker regions of MutL. These results indicate that roadblock bypass can be fully attributed to the long, disordered linker regions in MutL and establish that communication during MMR initiation occurs along the DNA backbone