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Science (New York, N.Y.) Feb 2016Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net...
Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, relativistic quantum mechanics allows for generating current-induced internal fields whose sign alternates with the periodicity of the antiferromagnetic lattice. Using these fields, which couple strongly to the antiferromagnetic order, we demonstrate room-temperature electrical switching between stable configurations in antiferromagnetic CuMnAs thin-film devices by applied current with magnitudes of order 10(6) ampere per square centimeter. Electrical writing is combined in our solid-state memory with electrical readout and the stored magnetic state is insensitive to and produces no external magnetic field perturbations, which illustrates the unique merits of antiferromagnets for spintronics.
PubMed: 26841431
DOI: 10.1126/science.aab1031 -
Orthopaedics & Traumatology, Surgery &... Dec 2021Arthroscopic rotator cuff repair most commonly results in good clinical outcomes, however understanding of predictive factors influencing the final clinical outcome is...
HYPOTHESIS/BACKGROUND
Arthroscopic rotator cuff repair most commonly results in good clinical outcomes, however understanding of predictive factors influencing the final clinical outcome is limited.
AIM
The purpose of our study was to evaluate clinical outcomes of patients with healed supraspinatus tendon after arthroscopic rotator cuff repair and to identify its pre- and peri-operative predictive factors of good clinical results.
METHODS
A multi-center prospective study followed up 188 patients, who had a healed tendon after an arthroscopic repair of isolated supraspinatus tear. Inclusion criteria were: age under 70 years old, isolated supraspinatus tear, stage 0 or I of fatty infiltration, healed supraspinatus tendon at one year postoperatively and the same arthroscopic double row rotator cuff repair used in all patients. Clinical assessment used Constant Murley Score (CMS) and Subjective Shoulder Value (SSV) preoperatively and at one year postoperatively. Ultrasound (US) control checked tendon repair quality based on Sugaya classification. Types I-II-III were considered as healed.
RESULTS
The average age of our cohort was 57.57 (range; 41 to 70) years and the female to male ratio was 1.14 (range; 100 to 87). The average preoperative CMS was 53.75±13.50 (mean±SD; range; 16 to 83). At final follow up, the average postoperative CMS was 79.95±12.05 (mean±SD; range; 28 to 100). 12.22% (23/188) of patients, who had a CMS score below 70, had a clinically significant difference compared to the average CMS, due to the fact that the minimal clinically significant difference (MCID) in CMS is 10. A statistical analysis has shown that in patients with lower scores there was only a significant dominance of females (p-value=0.001). No difference was found in regards to age, preoperative CMS, fatty degeneration and other factors.
CONCLUSION
Our study showed that despite all patients had a healed repair of supraspinatus, not all of them experienced a good final clinical outcome. The only factor negatively influencing the final clinical outcome was a female gender. No other structural factors seemed to influence the final clinical results. Futures studies should focus more on analyzing which personality traits and other psychosocial factors play an important role in determining the final outcome after arthroscopic rotator cuff repair.
LEVEL OF EVIDENCE
III; retrospective cohort study.
Topics: Adult; Aged; Arthroscopy; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Prospective Studies; Retrospective Studies; Rotator Cuff; Rotator Cuff Injuries; Treatment Outcome
PubMed: 34628088
DOI: 10.1016/j.otsr.2021.103100 -
Philosophical Transactions. Series A,... Oct 2018Maxwell's four differential equations describing electromagnetism are among the most famous equations in science. Feynman said that they provide four of the seven...
Maxwell's four differential equations describing electromagnetism are among the most famous equations in science. Feynman said that they provide four of the seven fundamental laws of classical physics. In this paper, we derive Maxwell's equations using a well-established approach for deriving time-dependent differential equations from static laws. The derivation uses the standard Heaviside notation. It assumes conservation of charge and that Coulomb's law of electrostatics and Ampere's law of magnetostatics are both correct as a function of time when they are limited to describing a local system. It is analogous to deriving the differential equation of motion for sound, assuming conservation of mass, Newton's second law of motion and that Hooke's static law of elasticity holds for a system in local equilibrium. This work demonstrates that it is the conservation of charge that couples time-varying -fields and -fields and that Faraday's Law can be derived without any relativistic assumptions about Lorentz invariance. It also widens the choice of axioms, or starting points, for understanding electromagnetism.This article is part of the theme issue 'Celebrating 125 years of Oliver Heaviside's 'Electromagnetic Theory''.
PubMed: 30373937
DOI: 10.1098/rsta.2017.0447 -
HardwareX Sep 2023Wearable technology, such as electronic components integrated into clothing or worn as accessories, is becoming increasingly prevalent in fields like healthcare and...
Wearable technology, such as electronic components integrated into clothing or worn as accessories, is becoming increasingly prevalent in fields like healthcare and biomedical monitoring. These devices allow for continuous monitoring of important biomarkers for medical diagnosis, monitoring of physiological health, and evaluation. However, an open-source wearable potentiostat is a relatively new technology that still faces several design limitations such as short battery lifetime, bulky size, heavy weight, and the requirement for a wire for data transmission, which affects comfortability during long periods of measurement. In this work, an open-source wearable potentiostat device named We-VoltamoStat is developed to allow interested parties to use and modify the device for creating new products, research, and teaching purposes. The proposed device includes improved and added features, such as wireless real-time signal monitoring and data collection. It also has an ultra-low power consumption battery estimated to deliver 15 mA during operating mode for 33 h and 20 min and 5 mA during standby mode for 100 h without recharging. Its convenience for wearable applications, tough design, and compact size of 67x54x38 mm make it suitable for wearable applications. Cost-effectiveness is another advantage, with a price less than 120 USD. Validation performance tests indicate that the device has good accuracy, with an R2 value of 0.99 for linear regression of test accuracy on milli-, micro-, and nano-Ampere detection. In the future, it is recommended to improve the design and add more features to the device, including new applications for wearable potentiostats.
PubMed: 37396412
DOI: 10.1016/j.ohx.2023.e00441 -
Nature Communications Jul 2023Hydrogen production coupled with biomass upgrading is vital for future sustainable energy developments. However, most biomass electrooxidation reactions suffer from high...
Hydrogen production coupled with biomass upgrading is vital for future sustainable energy developments. However, most biomass electrooxidation reactions suffer from high working voltage and low current density, which substantially hinder large-scale industrial applications. Herein, we report an acidic hydrogen production system that combined anodic ascorbic acid electrooxidation with cathodic hydrogen evolution. Unlike C-H and O-H bonds cleavage with slow kinetics in conventional organic oxidation, the highly active enol structure in ascorbic acid allows for an ultralow overpotential of only 12 mV@10 mA/cm using Fe single-atom catalysts, and reaches 1 A/cm at only 0.75 V (versus reversible hydrogen electrode) with approximately 100% Faraday efficiency for hydrogen production. Furthermore, the fabricated two-electrode membrane-free electrolyser delivers an industrial current density of 2 A/[email protected] V at 60 °C (2.63 kWh/Nm H), which requires half of the electricity consumption in conventional water electrolysis (~5 kWh/Nm H). This work provides a new avenue for achieving industrial-scale hydrogen production from biomass.
Topics: Ascorbic Acid; Biomass; Electricity; Electrodes; Hydrogen
PubMed: 37452034
DOI: 10.1038/s41467-023-39848-w -
Medical Physics Oct 2022In proton therapy dose calculation, Monte Carlo (MC) simulations are superior in accuracy but more time consuming, compared to analytical calculations. Graphic...
BACKGROUND
In proton therapy dose calculation, Monte Carlo (MC) simulations are superior in accuracy but more time consuming, compared to analytical calculations. Graphic processing units (GPUs) are effective in accelerating MC simulations but may suffer thread divergence and racing condition in GPU threads that degrades the computing performance due to the generation of secondary particles during nuclear reactions.
PURPOSE
A novel concept of virtual particle (VP) MC (VPMC) is proposed to avoid simulating secondary particles in GPU-accelerated proton MC dose calculation and take full advantage of the computing power of GPU.
METHODS
Neutrons and gamma rays were ignored as escaping from the human body; doses of electrons, heavy ions, and nuclear fragments were locally deposited; the tracks of deuterons were converted into tracks of protons. These particles, together with primary and secondary protons, are considered to be the realistic particles. Histories of primary and secondary protons were replaced by histories of multiple VPs. Each VP corresponded to one proton (either primary or secondary). A continuous-slowing-down-approximation model, an ionization model, and a large angle scattering event model corresponding to nuclear interactions were developed for VPs by generating probability distribution functions (PDFs) based on simulation results of realistic particles using MCsquare. For efficient calculations, these PDFs were stored in the Compute Unified Device Architecture textures. VPMC was benchmarked with TOPAS and MCsquare in phantoms and with MCsquare in 13 representative patient geometries. Comparisons between the VPMC calculated dose and dose measured in water during patient-specific quality assurance (PSQA) of the selected 13 patients were also carried out. Gamma analysis was used to compare the doses derived from different methods and calculation efficiencies were also compared.
RESULTS
Integrated depth dose and lateral dose profiles in both homogeneous and inhomogeneous phantoms all matched well among VPMC, TOPAS, and MCsquare calculations. The 3D-3D gamma passing rates with a criterion of 2%/2 mm and a threshold of 10% was 98.49% between MCsquare and TOPAS and 98.31% between VPMC and TOPAS in homogeneous phantoms, and 99.18% between MCsquare and TOPAS and 98.49% between VPMC and TOPAS in inhomogeneous phantoms, respectively. In patient geometries, the 3D-3D gamma passing rates with 2%/2 mm/10% between dose distributions from VPMC and MCsquare were 98.56 ± 1.09% in patient geometries. The 2D-3D gamma analysis with 3%/2 mm/10% between the VPMC calculated dose distributions and the 2D measured planar dose distributions during PSQA was 98.91 ± 0.88%. VPMC calculation was highly efficient and took 2.84 ± 2.44 s to finish for the selected 13 patients running on four NVIDIA Ampere GPUs in patient geometries.
CONCLUSION
VPMC was found to achieve high accuracy and efficiency in proton therapy dose calculation.
Topics: Deuterium; Humans; Monte Carlo Method; Proton Therapy; Protons; Water
PubMed: 35960865
DOI: 10.1002/mp.15913 -
Microbial Ecology Oct 2023Arctic soils are constantly subjected to microbial invasion from either airborne, marine, or animal sources, which may impact local microbial communities and ecosystem...
Arctic soils are constantly subjected to microbial invasion from either airborne, marine, or animal sources, which may impact local microbial communities and ecosystem functioning. However, in winter, Arctic soils are isolated from outside sources other than snow, which is the sole source of microorganisms. Successful colonisation of soil by snow microorganisms depends on the ability to survive and compete of both, the invading and resident community. Using shallow shotgun metagenome sequencing and amplicon sequencing, this study monitored snow and soil microbial communities throughout snow melt to investigate the colonisation process of Arctic soils. Microbial colonisation likely occurred as all the characteristics of successful colonisation were observed. The colonising microorganisms originating from the snow were already adapted to the local environmental conditions and were subsequently subjected to many similar conditions in the Arctic soil. Furthermore, competition-related genes (e.g. motility and virulence) increased in snow samples as the snow melted. Overall, one hundred potentially successful colonisers were identified in the soil and, thus, demonstrated the deposition and growth of snow microorganisms in soils during melt.
Topics: Soil; Ecosystem; Snow; Arctic Regions
PubMed: 36939866
DOI: 10.1007/s00248-023-02204-y -
Proteins Jun 2015As the volume of data relating to proteins increases, researchers rely more and more on the analysis of published data, thus increasing the importance of good access to...
As the volume of data relating to proteins increases, researchers rely more and more on the analysis of published data, thus increasing the importance of good access to these data that vary from the supplemental material of individual articles, all the way to major reference databases with professional staff and long-term funding. Specialist protein resources fill an important middle ground, providing interactive web interfaces to their databases for a focused topic or family of proteins, using specialized approaches that are not feasible in the major reference databases. Many are labors of love, run by a single lab with little or no dedicated funding and there are many challenges to building and maintaining them. This perspective arose from a meeting of several specialist protein resources and major reference databases held at the Wellcome Trust Genome Campus (Cambridge, UK) on August 11 and 12, 2014. During this meeting some common key challenges involved in creating and maintaining such resources were discussed, along with various approaches to address them. In laying out these challenges, we aim to inform users about how these issues impact our resources and illustrate ways in which our working together could enhance their accuracy, currency, and overall value.
Topics: Data Curation; Databases, Protein; Molecular Sequence Annotation; Proteins
PubMed: 25820941
DOI: 10.1002/prot.24803 -
Sensors (Basel, Switzerland) Dec 2021Light beams carrying Orbital Angular Momentum (OAM), also known as optical vortices (OV), have led to fascinating new developments in fields ranging from quantum...
Light beams carrying Orbital Angular Momentum (OAM), also known as optical vortices (OV), have led to fascinating new developments in fields ranging from quantum communication to novel light-matter interaction aspects. Even though several techniques have emerged to synthesize these structured-beams, their detection, in particular, single-shot amplitude, wavefront, and modal content characterization, remains a challenging task. Here, we report the single-shot amplitude, wavefront, and modal content characterization of ultrashort OV using a Shack-Hartmann wavefront sensor. These vortex beams are obtained using spiral phase plates (SPPs) that are frequently used for high-intensity applications. The reconstructed wavefronts display a helical structure compatible with the topological charge induced by the SPPs. We affirm the accuracy of the optical field reconstruction by the wavefront sensor through an excellent agreement between the numerically backpropagated and experimentally obtained intensity distribution at the waist. Consequently, through Laguerre-Gauss (LG) decomposition of the reconstructed fields, we reveal the radial and azimuthal mode composition of vortex beams under different conditions. The potential of our method is further illustrated by characterizing asymmetric Gaussian vortices carrying fractional average OAM, and a realtime topological charge measurement at a 10Hz repetition rate. These results can promote Shack-Hartmann wavefront sensing as a single-shot OV characterization tool.
PubMed: 35009674
DOI: 10.3390/s22010132 -
Orthopaedics & Traumatology, Surgery &... Dec 2021The early postoperative period after anterior cruciate ligament reconstruction (ACL) is critical for optimal functional recovery. Despite an abundance of literature,...
INTRODUCTION
The early postoperative period after anterior cruciate ligament reconstruction (ACL) is critical for optimal functional recovery. Despite an abundance of literature, there is no consensus regarding good practices. This period is often under-considered by orthopedic surgeons. The aim of this study was to identify early postoperative practices after ACL reconstruction in France.
HYPOTHESIS
The hypothesis was that there was a discrepancy between validated data in the literature and the current practices of orthopedic surgeons in France.
MATERIAL AND METHODS
In 2019, a questionnaire was sent to all the members of the French Arthroscopy Society to investigate their postoperative practices after ACL reconstruction. Two hundred sixty-nine members responded. Surgeons were divided into two groups of experienced (n=137) and less experienced (n=132) surgeons, according to the number of ACL reconstructions performed per year (
RESULTS
ACL reconstruction was performed as an outpatient procedure in 72.9% of cases. This rate increased with surgical experience (p=0.009×10). Among measures to prevent effusion, cryotherapy was recommended in 97.8% of cases. The experienced group more often used compressive cryotherapy devices (p=0.004). Rehabilitation was started immediately in 75.5% of cases, with as main objective recovery of full extension (89.6%). Weight-bearing was allowed in 98.5% of cases and a brace was prescribed in 69.9% of cases. In the experienced group, braces were less frequent (p=0.02) and self-rehabilitation was preferred (p=0.0006).
CONCLUSION
Early postoperative practices after ACL reconstruction in France are related to surgical experience. The greater the surgical experience, the greater the role of joint effusion prevention and self-rehabilitation. Despite recommendations in the literature, a quarter of the French orthopedic surgeons who responded to this survey did not perform this procedure on an outpatient basis and more than two-thirds prescribed braces.
LEVEL OF EVIDENCE
IV.
Topics: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Braces; Humans; Postoperative Period; Weight-Bearing
PubMed: 34537390
DOI: 10.1016/j.otsr.2021.103065