A compact setup for behavioral studies measuring limb acceleration

Behavioral studies contribute largely to a broader understanding of human brain mechanisms and the process of learning and memory. An established method to quantify motor learning is the analysis of thumb activity. In combination with brain stimulation, the effect of various treatments on neural plasticity and motor learning can be assessed. So far, the setups for thumb abduction measurements employed consist of bulky amplifiers and digital-to-analog devices to record the data. We developed a compact hardware setup to measure acceleration data which can be integrated into a wearable, including a sensor board and a microcontroller board which can be connected to a PC via USB. Additionally, we provide two software packages including graphical user interfaces, one to communicate with the hardware and one to evaluate and process the data. This work demonstrates the construction and application of our setup at the example of thumb acceleration measurement with a custom made glove and its use for research. Using integrated circuits, the size of the measurement devices is reduced to this wearable. It is simple to construct and can be operated easily by non-technical staff.

Development of a density-based topology optimization of homogenized lattice structures for individualized hip endoprostheses and validation using micro-FE

Prosthetic implants, particularly hip endoprostheses, often lead to stress shielding because of a mismatch in compliance between the bone and the implant material, adversely affecting the implant's longevity and effectiveness. Therefore, this work aimed to demonstrate a computationally efficient method for density-based topology optimization of homogenized lattice structures in a patient-specific hip endoprosthesis. Thus, the root mean square error (RMSE) of the stress deviations between the physiological femur model and the optimized total hip arthroplasty (THA) model compared to an unoptimized-THA model could be reduced by 81 % and 66 % in Gruen zone (GZ) 6 and 7. However, the method relies on homogenized finite element (FE) models that only use a simplified representation of the microstructural geometry of the bone and implant. The topology-optimized hip endoprosthesis with graded lattice structures was synthesized using algorithmic design and analyzed in a virtual implanted state using micro-finite element (micro-FE) analysis to validate the optimization method. Homogenized FE and micro-FE models were compared based on averaged von Mises stresses in multiple regions of interest. A strong correlation (CCC > 0.97) was observed, indicating that optimizing homogenized lattice structures yields reliable outcomes. The graded implant was additively manufactured to ensure the topology-optimized result's feasibility.

Collinear Laser Spectroscopy of 2 ^{3}S_{1}→2 ^{3}P_{J} Transitions in Helium-like ^{12}C^{4+}

Transition frequencies and fine-structure splittings of the 2 ^{3}S_{1}→2 ^{3}P_{J} transitions in helium-like ^{12}C^{4+} were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased by more than 3 orders of magnitude with respect to previous measurements, enabling tests of recent nonrelativistic (NR) QED calculations including terms up to mα^{7}. Deviations between the theoretical and experimental values are within theoretical uncertainties and are ascribed to mα^{8} and higher-order contributions in the series expansion of the NR QED calculations. Finally, prospects for an all-optical charge radius determination of light isotopes are evaluated.

Nuclear Charge Radius of ^{26m}Al and Its Implication for V_{ud} in the Quark Mixing Matrix

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15)  fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed β decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

Determination of the Thermomigration Force on Adatoms

Thermal gradients in nanomaterials can cause surface mass transport phenomena. However, the atomic fluxes are challenging to quantify and the underlying atomic mechanisms are complex. Using low energy electron microscopy we have examined in operando, under a thermal gradient of 10^{4}  K/m, the thermomigration of supercooled Si(111)-1×1 advacancy islands. The islands move in the direction of the thermal gradient at 0.26±0.06  nm/s. This reveals that the adatoms move toward the cold region and the effective force exerted on Si adatoms is 1.4±0.4×10^{-8}  eV/nm. We quantify the heat of transport of Si atoms Q^{*}=1.2±0.4  eV and show that it corresponds to the combined effects of adatom creation at step edges and adatom diffusion on atomically flat terraces.

First Observation of Cyclotron Radiation from MeV-Scale e^{±} following Nuclear β Decay

We present an apparatus for detection of cyclotron radiation yielding a frequency-based β^{±} kinetic energy determination in the 5 keV to 2.1 MeV range, characteristic of nuclear β decays. The cyclotron frequency of the radiating β particles in a magnetic field is used to determine the β energy precisely. Our work establishes the foundation to apply the cyclotron radiation emission spectroscopy (CRES) technique, developed by the Project 8 Collaboration, far beyond the 18-keV tritium endpoint region. We report initial measurements of β^{-}'s from ^{6}He and β^{+}'s from ^{19}Ne decays to demonstrate the broadband response of our detection system and assess potential systematic uncertainties for β spectroscopy over the full (MeV) energy range. To our knowledge, this is the first direct observation of cyclotron radiation from individual highly relativistic β's in a waveguide. This work establishes the application of CRES to a variety of nuclei, opening its reach to searches for new physics beyond the TeV scale via precision β-decay measurements.

Bayesian approaches to include real-world data in clinical studies

Randomized clinical trials have been the mainstay of clinical research, but are prohibitively expensive and subject to increasingly difficult patient recruitment. Recently, there is a movement to use real-world data (RWD) from electronic health records, patient registries, claims data and other sources in lieu of or supplementing controlled clinical trials. This process of combining information from diverse sources calls for inference under a Bayesian paradigm. We review some of the currently used methods and a novel non-parametric Bayesian (BNP) method. Carrying out the desired adjustment for differences in patient populations is naturally done with BNP priors that facilitate understanding of and adjustment for population heterogeneities across different data sources. We discuss the particular problem of using RWD to create a synthetic control arm to supplement single-arm treatment only studies. At the core of the proposed approach is the model-based adjustment to achieve equivalent patient populations in the current study and the (adjusted) RWD. This is implemented using common atoms mixture models. The structure of such models greatly simplifies inference. The adjustment for differences in the populations can be reduced to ratios of weights in such mixtures. This article is part of the theme issue 'Bayesian inference: challenges, perspectives, and prospects'.

Residence times of groundwater along a flow path in the Great Artesian Basin determined by 81Kr, 36Cl and 4He: Implications for palaeo hydrogeology

Understanding the age distribution of groundwater can provide information on both the recharge history as well as the geochemical evolution of groundwater flow systems. Of the few candidates available that can be used to date old groundwater, ⁸¹Kr shows the most promise because its input function is constant through time and there are less sources and sinks to complicate the dating procedure in comparison to traditional tracers such as ³⁶Cl and ⁴He. In this paper we use ⁸¹Kr in a large groundwater basin to obtain a better understanding of the residence time distribution of an unconfined-confined aquifer system. A suite of environmental tracers along a groundwater flow path in the south-west Great Artesian Basin of Australia have been sampled. All age tracers (⁸⁵Kr, ³⁹Ar ¹⁴C, ⁸¹Kr, ³⁶Cl and ⁴He) display a consistent increase in groundwater age with distance from the recharge area indicating the presence of a connected flow path. Assuming that ⁸¹Kr is the most accurate dating technique the ³⁶Cl/Cl systematics was unravelled to reveal information on recharge mechanism and chloride concentration at the time of recharge. Current-day recharge occurs via ephemeral river recharge beneath the Finke River, while diffuse recharge is minor in the young groundwaters. Towards the end of the transect the influence of ephemeral recharge is less while diffuse recharge and the initial chloride concentration at recharge were higher.

β-Nuclear-Recoil Correlation from ^{6}He Decay in a Laser Trap

We report the first precise measurement of a β-recoil correlation from a radioactive noble gas (^{6}He) confined via a magneto-optical trap. The measurement is motivated by the search for exotic tensor-type contributions to the charged weak current. Interpreted as tensor currents with right-handed neutrinos, the measurements yield |C_{T}/C_{A}|^{2}≤0.022 (90% confidence limit, C.L.). On the other hand, for left-handed neutrinos the limits are 0.007<C_{T}/C_{A}<0.111 (90% C.L.). The sensitivity of the present measurement is mainly limited by experimental uncertainties in determining the time response properties and the distance between the atom cloud and the microchannel plate used for recoil ion detection.

Robotic distal pancreatectomy, a novel standard of care? First benchmark values for surgical outcomes from 14 international expert centers

Objective

Robotic distal pancreatectomy (DP) is emerging as the preferred treatment for body and tail tumors of the pancreas. To enable conclusive comparisons with the standard open or laparoscopic approaches and robotic surgery among centers, novel benchmark outcome values are urgently needed. Therefore, the aim of this study was to identify benchmark values from expert centers beyond the learning curve.

Methods

This multicenter study analyzed outcomes from consecutive patients undergoing robotic DP for resectable malignant or benign lesions from 14 international expert centers. After the learning curve, defined as the first 10 cases of robotic DP, all consecutive patients were included from the start of the program up to June 2020 with a minimum follow-up of 1 year. Benchmark patients were those without significant comorbidities including obesity (BMI &gt;35 kg/m2) cardiac disease, chronic pulmonary disease.

Benchmark cutoff values were derived from the 75th or the 25th percentile of the median values of all benchmark centers.

Results

After reaching the learning curve, 289 (47%) of a total of 614 consecutive patients qualified as benchmark cases. The proportion of benchmark patients varied between 24%-64% per center. Benchmark cut-offs showed a low 6 month- postoperative mortality (&lt;0.6%), but high overall morbidity (&lt;58.3%). Benchmark cutoffs for operative time (&lt;300 min), conversion rate (&lt;3%), clinically relevant pancreatic fistulas (&lt;26.9%), CCI at 90-days (&lt;14.8), hospital stay (&lt;7 days) and readmission rate (&lt;22.9%). Benchmark cut-offs for complications remained unchanged after 3 months follow-up. For ductal adenocarcinoma benchmark cutoffs for number of lymph nodes were &gt; 19 with an R0 resection rate of &gt; 85%, and an overall survival of &gt;86% and &gt;52% after 1- and 5-years, respectively. Centers with a low cohort of benchmark patients (more difficult cases) had less clinically relevant pancreatic fistula (9% vs. 23%) and less overall complications (32% vs. 48%).

Conclusion

This benchmark analysis sets novel reference values for robotic DP, indicating favorable outcomes as compared to laparoscopic and open DP. These references values may serve for quality control of surgery in centers embarking in robotic DP, and include the procedure in the standard of care.

Prehabilitation in patients undergoing colorectal surgery fails to confer reduction in overall morbidity: Results of a single-center, single-blinded, randomized controlled trial

Objective

Patients undergoing major surgery are prone to a functional decline due to the impairment of muscle, cardiorespiratory and neurological function as a response to surgical stress. Currently, there are solely weak recommendations in the ERAS protocol regarding the role of preoperative physical activity and prehabilitation in patients undergoing colorectal surgery. Studies in heterogenous cohorts showed contradictory results regarding the impact of prehabilitation on the reduction of postoperative complications. This randomized controlled trial assesses the impact of prehabilitation on postoperative complications in patients undergoing colorectal surgery within an ERAS protocol.

Methods

Between July 2016 and June 2019, a single-center, single-blinded , randomized controlled trial designed to test whether physiotherapeutic prehabilitation vs. normal physical activities prior to colorectal surgery may decrease morbidity within a stringent ERAS protocol was carried out. The primary endpoint was postoperative complications assessed by Comprehensive Complications Index (CCI®). Primary and secondary endpoints for both groups were analyzed and compared.

Results

A total of 107 patients (54 in the pERACS and 53 in the control cohort) were included in the study and randomized. Dropout rate was 4.5% (n = 5). Mean age (SD) in the control cohort was 65 (29–86) and 66 (24–90) years in pERACS cohort. The pERACS cohort contained more female patients (40% vs. 55%, p = 0.123) and a higher percentage of colorectal adenocarcinoma (32% vs. 23%, p = 0.384) although not significant. Almost all patients underwent minimally invasive surgery in both cohorts (96% vs 98%, p = 1.000). There was no between-cohort difference in the primary outcome measure 30-day Comprehensive Complications Index (15 [0 – 49] vs. 18 [0 – 43], p = 0.059). Secondary outcome as complications assessed according to Clavien-Dindo, length of hospital stay, reoperation rate and mortality showed no difference between both cohorts.

Conclusion

Routine physiotherapeutic prehabilitation cannot be recommended for patients undergoing colorectal surgery within an ERAS protocol (Grade A recommendation). To eliminate other confounders like geographical difference or difference in surgical technique, further multicenter RCTs are needed.

Mechanism and dynamics of fatty acid photodecarboxylase

Fatty acid photodecarboxylase (FAP) is a photoenzyme with potential green chemistry applications. By combining static, time-resolved, and cryotrapping spectroscopy and crystallography as well as computation, we characterized Chlorella variabilis FAP reaction intermediates on time scales from subpicoseconds to milliseconds. High-resolution crystal structures from synchrotron and free electron laser x-ray sources highlighted an unusual bent shape of the oxidized flavin chromophore. We demonstrate that decarboxylation occurs directly upon reduction of the excited flavin by the fatty acid substrate. Along with flavin reoxidation by the alkyl radical intermediate, a major fraction of the cleaved carbon dioxide unexpectedly transformed in 100 nanoseconds, most likely into bicarbonate. This reaction is orders of magnitude faster than in solution. Two strictly conserved residues, R451 and C432, are essential for substrate stabilization and functional charge transfer.

Ultrahigh vacuum packaging and surface cleaning for quantum devices

We describe design, implementation, and performance of an ultra-high vacuum (UHV) package for superconducting qubit chips or other surface sensitive quantum devices. The UHV loading procedure allows for annealing, ultra-violet light irradiation, ion milling, and surface passivation of quantum devices before sealing them into a measurement package. The package retains vacuum during the transfer to cryogenic temperatures by active pumping with a titanium getter layer. We characterize the treatment capabilities of the system and present measurements of flux tunable qubits with an average T₁ = 84 µs and T₂ ^echo=134μs after vacuum-loading these samples into a bottom loading dilution refrigerator in the UHV-package.

Dashboard Visualization of Information for Emergency Medical Services

In emergency situations, every minute counts. Therefore, staff of emergency medical services (EMS) require easily accessible sources of information to organize and coordinate their work as quickly as possible. Digital dashboards can visualize various information at a glance and have thus potential to meet this need. We developed in cooperation with the Emmental Hospital a prototype of a dashboard, which aims to improve organizational aspects of the EMS.

METHOD

A literature search was conducted in PubMed, IEEE and ACM. The goal was to identify design principles for dashboards. Additionally, several interviews and meetings were held with the EMS staff of the Emmental Hospital and with those of another hospital. The aim was to identify requirements of the EMS staff towards such an organizational dashboard and to transform them into use cases.

RESULTS

Considering the collected requirements and standards of dashboard design, a prototype of a dashboard was developed. It consists of several modules that show relevant information items such as news or traffic information. Due to this modular development, content is easily interchangeable. The most important information for the EMS is shown on the dashboard aiming at saving time for information gathering.

CONCLUSION

A digital dashboard offers many advantages and optimization possibilities compared to an analog whiteboard. For example, such a dashboard can be connected to other systems and data can be automatically included. Although we developed our dashboard in cooperation with the EMS of a specific hospital, it can easily be applied and adjusted to other EMS. As a next step, we will perform usability tests with the prototype and start implementing the dashboard.

Urbanisation is a main driver for Aedes aegypti dynamics and arboviral risk in Côte d’Ivoire

Background

Aedes mosquito-borne arboviruses have (re-)emerged and caused considerable public health concerns in major sub-Saharan African cities subjected to rapid urbanisation. We assessed the effects of urbanisation on Aedes aegypti dynamics and biting pattern, and the risk of transmission of yellow fever (YF) and dengue (DEN) viruses along urban-rural gradient in Côte d'Ivoire.

Methods

We collected Aedes mosquitoes as eggs, larvae/pupae, and adults seasonally in urban, suburban and rural areas using ovitrap, larval survey and human-baited double net trap methods from January 2015 to December 2016. We sampled household data and characterised Aedes larval breeding sites. Ae. aegypti indices and biting rates were compared by area.

Results

Ae. aegypti was the most abundant species in all areas. It showed higher abundance in urban areas (n = 26,072; 99.4%). Larval indices were associated with human activities, including waste and water management. Tires and discarded containers were the most productive breeding sites in all areas. Household water receptacles displayed high Aedes-positive rate (23.6%) in urban areas. Positive ovitrap index was higher in urban (53.5%) compared to suburban (43.1%) and rural (29.7%). Stegomyia indices were highest in urban followed by suburban and rural areas, with respective house index of 67.2, 51.4 and 27.8, container index of 57.1, 43.5 and 19.7, and Breteau index of 95.2, 78.9 and 8.8. Biting rate was 4.3 and 2.7-fold higher in urban (83.5 bite/person/day) and suburban (52.1 bite/person/day) compared to rural (19.4 bite/person/day), respectively. Ae. aegypti indices were higher during rainy seasons.

Conclusions

In Côte d'Ivoire, urbanisation raised Ae. aegypti abundance and biting rate. As a result, YF and DEN risk indices were above WHO-established epidemic thresholds in urban area thus exposing local communities to high risk of getting diseases. Integrated community-based vector control programs should be applied to reduce arboviral risk.

Key messages

Urbanisation raises Aedes aegypti abundance and arboviral disease risk in Côte d’Ivoire. Integrated community clean-up actions are required to control Aedes vectors.

Investigation of the susceptibility of Candida auris and Candida albicans to chemical disinfectants using European Standards EN 13624 and EN 16615

BACKGROUND

Since the first appearance of Candida auris in 2009, this yeast has become a relevant pathogen in the clinical field. C. auris has been detected on various surfaces in health facilities, and is therefore a target for appropriate disinfection procedures. Preventive measures have to be implemented based on disinfectants with proven efficacy against C. auris.

AIM

The chemical tolerance of C. auris was compared with the surrogate test organism Candida albicans as established in the European standards (EN). In this way, conclusions will be drawn as to whether the disinfectants tested according to EN 13624 and EN 16615 are at least equally effective against C. auris.

METHODS

The chemical susceptibility of C. auris and C. albicans was investigated using standardized EN test protocols. EN 13624 and EN 16615 were used in this study to examine two commercially available surface disinfectants based on alcohol and quaternary ammonium compounds (QACs), respectively. In addition, the survival rates of the two yeast species were studied on a defined test surface simulating practical conditions.

FINDINGS

In comparison with C. albicans, C. auris was found to be significantly more susceptible to the alcohol- and QAC-based disinfectants used in this study. C. albicans was found to be more tolerant to drying on the test surface in EN 16615, yielding higher recovery rates.

CONCLUSION

C. albicans is a suitable surrogate test organism when targeting yeasticidal efficacy, which, based on EN 13624 and EN 16615, includes efficacy against the human pathogen C. auris.