Effective temperature for an intermittent bistable potential.

Thermodynamics of far-from-equilibrium systems often require measurement of effective parameters such as temperature. Whether such approach is valid for the general case of resetting protocols, active systems, or of confined systems under time-varying fields is still under investigation. We report on the effect of switching ON-OFF of an asymmetric bistable potential to the mean first passage time (MFPT) of a probed particle to go from one potential minima to the other. Experimental results coupled with numerical simulations shows the potential becoming more symmetric at slow switching. Moreover, the MFPT deviates from equilibrium condition with an effective temperature, Teff < T, at slow switching but approaches room temperature, T, at fast switching. For each switching rate, we quantify how far the system is from equilibrium by measuring deviation from a detailed balance like relation and the net circulation of flux present in phase-space. Both analysis suggest equilibrium condition are met at high switching.

Primary Retrograde Tibiotalocalcaneal Nailing in an Elderly Osteoporotic Patient With Ankle Fracture: A Case Report.

Introduction: Ankle fractures are a common orthopedic injury traditionally treated with open reduction and internal fixation or conservative management. One complication introduced with open reduction and internal fixation is the requirement for non or partial weight bearing in the post-operative period. This requirement poses a unique challenge for patients who may not comply with these weight-bearing restrictions. This case is the first known article that specifically illustrates the validity and effectiveness of retrograde tibiotalocalcaneal (TTC) nailing for patients who are unlikely to follow weight-bearing restrictions. Case Report: An 83-year-old Caucasian female with idiopathic mild mental retardation and Alzheimer's presented with a minimally displaced trimalleolar ankle fracture and was treated at a single urban hospital with a retrograde TTC nail secondary to her inability to adhere to weight-bearing restrictions post-operatively. Pertinent demographic, clinical, radiographic, and surgical data were collected. The patient had minimal post-operative pain, was able to bear weight on the day of surgery, and had no post-operative complications. Conclusion: This case report demonstrates that the use of a TTC nail is a safe and effective mode of fixation for ankle fractures in patient populations who may not adhere to weight-bearing restrictions post-operatively. The main benefits of fixation with a TTC nail are the ability to weight bear as tolerated post-operatively and decreased wound complications while having similar functional outcomes to open reduction and internal fixation. We suggest the use of TTC nails for ankle fractures in select patients who may not adhere to weight-bearing restrictions post-operatively.

Differences Between Patients With Diabetes Mellitus and Those Without in Cases of Necrotizing Fasciitis.

Purposes This study aims to evaluate further differences between patients with diabetes and those without who have been diagnosed with necrotizing fasciitis (NF) to assist clinicians in improving morbidity and mortality. Methods All patients diagnosed with NF of an extremity were retrospectively reviewed and divided into two groups based on a diagnosis of diabetes. Patient charts were reviewed to obtain multiple variables, which were compared between groups. Results From 2015 to 2021, 115 patients underwent surgical intervention due to concern for NF of an extremity with 92 patients included for data computation. Patients with diabetes had an average Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score of 9.02 compared to 7.24 (p=0.02). Patients with diabetes had a significantly higher rate of undergoing amputation when diagnosed with NF (p<0.0001). The mortality rate for diabetes and non-diabetes cohorts were 30.9% and 18.9%, respectively (p=0.2). Conclusion This study demonstrated that patients with diabetes with confirmed NF of an extremity had a significantly higher LRINEC score were more likely to undergo an amputation primarily, and were more likely to have a polymicrobial infection compared to those without. The overall mortality rate of NF was 26.1%.

Nitrate-Stimulated Release of Naturally Occurring Sedimentary Uranium.

Groundwater uranium (U) concentrations have been measured above the U.S. EPA maximum contaminant level (30 µg/L) in many U.S. aquifers, including in areas not associated with anthropogenic contamination by milling or mining. In addition to carbonate, nitrate has been correlated to uranium groundwater concentrations in two major U.S. aquifers. However, to date, direct evidence that nitrate mobilizes naturally occurring U from aquifer sediments has not been presented. Here, we demonstrate that the influx of high-nitrate porewater through High Plains alluvial aquifer silt sediments bearing naturally occurring U(IV) can stimulate a nitrate-reducing microbial community capable of catalyzing the oxidation and mobilization of U into the porewater. Microbial reduction of nitrate yielded nitrite, a reactive intermediate, which was further demonstrated to abiotically mobilize U from the reduced alluvial aquifer sediments. These results indicate that microbial activity, specifically nitrate reduction to nitrite, is one mechanism driving U mobilization from aquifer sediments in addition to previously described bicarbonate-driven desorption from mineral surfaces, such as Fe(III) oxides.

Outpatient Surgery for Rib Fracture Fixation: A Report of Three Cases.

Rib fractures are common injuries observed in trauma patients that will often heal without operative intervention. However, patients can infrequently have continued pain. Operative fixation of these symptomatic rib fractures has traditionally led to the patient requiring hospital admission for observation and pain control. The purpose of this study was to review three cases of outpatient rib fracture, open reduction and internal fixation (ORIF) surgery. Three patients with symptomatic rib fractures treated with ORIF at a single urban level one trauma center underwent outpatient same-day surgery. Pertinent demographic, clinical, radiographic, and surgical data were collected. All patients had decreased preoperative pain and no complications. This case series demonstrates that outpatient surgery for rib fracture ORIF can be performed safely in a select patient population. Additionally, it has similar efficacy as inpatient operative fixation with the main added benefit being decreased costs to both the patient and the healthcare system. We suggest that outpatient operative fixation of rib fractures should be considered for select patients.

Reversibility in nonequilibrium steady states as a measure of distance from equilibrium.

From the detailed balance-like relation, we propose a measure, K^{*}, of a nonequilibrium steady-state (NESS) distance from equilibrium. We investigate in particular the NESS of a particle confined in a time-dependent harmonic potential of constant stiffness but with an ON-OFF state following a telegraph process. Experimental results coupled with simulations show that K^{*} increases at slow switching rates (far from equilibrium) and approaches to zero at equilibrium conditions. Thus, the steady-state distribution together with K^{*} fully characterizes a NESS.

Excitable dynamics of Physarum polycephalum plasmodial nodes under chemotaxis.

Recent results show that the chemotactic response of uni-cellular decentralized systems such as amoeboid and mammalian cells, is excitable. The same observation has not yet been reported for multi-nucleated decentralized biological systems. Here we present experimental results that shows the Physarum polycephalum plasmodial nodes spatio-temporal chemotactic dynamics as an excitable response. We found a highly optimized signal synthesis method wherein the Physarum nodes employ two intensity thresholds to properly navigate the chemoattractant field and generate corresponding spike dynamics in the node count. The node spike dynamics was found to correspond to the polarized-depolarized transition in the Physarum polycephalum morphology. Validation of our experimental observations via Brownian lattice simulations yields the same quantitative results with our experiments.

Uranium(VI) attenuation in a carbonate-bearing oxic alluvial aquifer.

Uranium minerals are commonly found in soils and sediment across the United States at an average concentration of 2-4 mg/kg. Uranium occurs in the environment primarily in two forms, the oxidized, mostly soluble uranium(VI) form, or the reduced, sparingly soluble reduced uranium(IV) form. Here we describe subsurface geochemical conditions that result in low uranium concentrations in an alluvial aquifer with naturally occurring uranium in soils and sediments in the presence of complexing ligands under oxidizing conditions. Groundwater was saturated with respect to calcite and contained calcium (78-90 mg/L) with elevated levels of carbonate alkalinity (291-416 mg/L as HCO3-). X-ray adsorption near edge structure (XANES) spectroscopy identified that sediment-associated uranium was oxidized as a uranium(VI) form (85%). Calcite was the predominant mineral by mass in the ultrafine fraction in uranium-bearing sediments (>16 mg/kg). Groundwater geochemical modeling indicated calcite and/or a calcium-uranyl-carbonate mineral such as liebigite in equilibrium with groundwater. The δ13C (0.57‰ ± 0.15‰) was indicative of abiotic carbonate deposition. Thus, solid-phase uranium(VI) associated with carbonate is likely maintaining uranium(VI) groundwater levels below the maximum contaminant level (MCL; 30 µg/L), presenting a deposition mechanism for uranium attenuation rather than solely a means of mobilization.

Evaluation of Mass Sensitive Micro-Array biosensors for their feasibility in multiplex detection of low molecular weight toxins using mycotoxins as model compounds.

Mycotoxins produced by Fusarium species including trichothecenes, zearalenone and fumonisins, can co-contaminate food and feed throughout the supply chain, including cereal grains and animal feeds. There is an increasing demand to enhance global food security by improving the monitoring of mycotoxins throughout our food supply chain. For time and cost-efficient analysis, rapid tests capable of detecting multiple toxins from a single sample are ideal. Considering these current trends in mycotoxin testing, this project examined the feasibility of using both a portable and non-portable mass-based biosensor for multiplex mycotoxin detection. The biosensor was a mass sensitive microarray (MSMA) which consisted of 4 × 16 miniaturized mass sensitive transducer pixels based on solidly mounted resonator (SMR) technology. Functionalisation of individual pixels on the sensor surface using nano-spotting technology for the simultaneous and semi-quantitative detection of three regulated mycotoxins: T2-toxin (T2) zearalenone (ZEN), and fumonisin B1 (FumB1) was examined. With the integration of portable and non-portable microfluidic devices for antibody and standard sample injections, competitive inhibition assays were developed followed by singleplex and multiplex calibration curves. The characteristics and performance of the MSMA were evaluated including sensitivity which was determined as the concentration causing 50% inhibition. Sensitivity of singleplex assays using the portable microfluidic device (PMD) were 1.3 ng/ml, 2.0 ng/ml and 6.8 ng/ml for T2, FumB1 and ZEN, respectively. Sensitivity of the multiplex assay again using the PMD was 6.1 ng/ml, 3.6 ng/ml and 2.4 ng/ml for T2, FumB1 and ZEN, respectively. The PMD was an easy to use and highly sensitive screening tool which has been demonstrated for the multiplex detection of three regulated mycotoxins. Analysis was in real time and results were fully digital. Since detection of analytes was by mass it was both a label-free and cost-efficient method proposed method of analysis for mycotoxins.

λ-like transition in the dynamics of ratchet gears in active bath.

To what extent the orientational order of self-propelling particles affects the dynamics of active bath-immersed ratchet devices remains unclear. We report experimental results of an inverse λ-like transition of the angular velocity of two ratchet gears in an active bath of self-propelling granular rods (SPRs) at different gear distances. The transition is caused by the phase transition in the orientational order of those SPRs located in the space between the gears. Brownian dynamics simulation of confined SPRs supports these observations. Thus, conditions for the upper bound efficiency of systems of active ratchet gears were obtained.

Dynamics of a ratchet gear powered by an active granular bath.

Recent experiments show universal features of ratchet gear dynamics that are powered by different types of active baths. We investigate further for the case of a ratchet gear in a bath of self-propelling granular rods (SPRs). The resulting angular velocity was found to follow a nonmonotonic dependence to the SPR concentration similar to the observation from other active bath systems. This behavior is caused by the interplay of the momentum transfer of the SPRs in the trapping regions of the gear and the mean velocity of the SPRs inside the bath. For all SPR concentrations, we found that the angular velocity is proportional to the product of the number of SPRs pushing the gear and the SPRs mean velocity.

The end user sensor tree: An end-user friendly sensor database.

Detailed knowledge regarding sensor based technologies for the detection of food contamination often remains concealed within scientific journals or divided between numerous commercial kits which prevents optimal connectivity between companies and end-users. To overcome this barrier The End user Sensor Tree (TEST) has been developed. TEST is a comprehensive, interactive platform including over 900 sensor based methods, retrieved from the scientific literature and commercial market, for aquatic-toxins, mycotoxins, pesticides and microorganism detection. Key analytical parameters are recorded in excel files while a novel classification system is used which provides, tailor-made, experts' feedback using an online decision tree and database introduced here. Additionally, a critical comparison of reviewed sensors is presented alongside a global perspective on research pioneers and commercially available products. The lack of commercial uptake of the academically popular electrochemical and nanomaterial based sensors, as well as multiplexing platforms became very apparent and reasons for this anomaly are discussed.

A land use regression model for explaining spatial variation in air pollution levels using a wind sector based approach.

Estimating pollutant concentrations at a local and regional scale is essential in environmental and health policy decision making. Here we present a novel land use regression (LUR) modelling methodology that exploits the high temporal resolution of fixed-site monitoring (FSM) to produce a national-scale air quality model for the key pollutant NO2. The methodology partitions concentration time series from a national FSM network into wind-dependent sectors or "wedges". A LUR model is derived using predictor variables calculated within the directional wind sectors, and compared against the long-term average concentrations within each sector. Validation results, based on 15 FSM training sites, show that the model captured 78% of the spatial variability in NO2 across the Republic of Ireland. This compares favourably to traditional LUR models based on purpose-designed monitoring campaigns despite using approximately half the number of monitoring points. Results also demonstrate the value of incorporating the relative position of emission source and receptor into the empirical LUR model structure. We applied the model at a high-resolution across the Republic of Ireland to enable applications such as the study of environmental exposure and human health, assessing representativeness of air quality monitoring networks and informing environmental management and policy makers. While the study focuses on Ireland, the methodology also has potential applicability for other criteria pollutants where appropriate FSM and meteorological networks exist.

A missense mutation in Katnal1 underlies behavioural, neurological and ciliary anomalies.

Microtubule severing enzymes implement a diverse range of tissue-specific molecular functions throughout development and into adulthood. Although microtubule severing is fundamental to many dynamic neural processes, little is known regarding the role of the family member Katanin p60 subunit A-like 1, KATNAL1, in central nervous system (CNS) function. Recent studies reporting that microdeletions incorporating the KATNAL1 locus in humans result in intellectual disability and microcephaly suggest that KATNAL1 may play a prominent role in the CNS; however, such associations lack the functional data required to highlight potential mechanisms which link the gene to disease symptoms. Here we identify and characterise a mouse line carrying a loss of function allele in Katnal1. We show that mutants express behavioural deficits including in circadian rhythms, sleep, anxiety and learning/memory. Furthermore, in the brains of Katnal1 mutant mice we reveal numerous morphological abnormalities and defects in neuronal migration and morphology. Furthermore we demonstrate defects in the motile cilia of the ventricular ependymal cells of mutants, suggesting a role for Katnal1 in the development of ciliary function. We believe the data we present here are the first to associate KATNAL1 with such phenotypes, demonstrating that the protein plays keys roles in a number of processes integral to the development of neuronal function and behaviour.

Erratum: Observation of the hyperfine spectrum of antihydrogen.

This corrects the article DOI: 10.1038/nature23446.

Antihydrogen accumulation for fundamental symmetry tests.

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.

Observation of the hyperfine spectrum of antihydrogen.

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 1013 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 104. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Cardiac arrest secondary to acute coronary syndrome: a 4-year observational study of patient characteristics and outcomes.

BACKGROUND: Cardiac arrest due to ischaemia is frequently the first manifestation of cardiovascular disease. We sought to describe the characteristics and outcomes of patients admitted to the Intensive Care Unit (ICU) with a diagnosis of cardiac arrest secondary to acute coronary syndrome (ACS). METHODS: We performed a retrospective analysis of patients admitted to the intensive care unit over a 4 year period. Baseline demographic characteristics, the use of therapeutic hypothermia, rates of percutaneous coronary intervention, co-morbidities and baseline left ventricular function were all documented. Outcomes included Glasgow Coma Scale (GCS) at time of discharge from the ICU, survival to hospital discharge, 6 months survival and left ventricular function at 6 months. RESULTS: We identified 31 admissions to the ICU following cardiac arrest due to ACS during the study period. 71 % of patients survived to hospital discharge and all of these were still alive at 6 months. 65 % had good neurological function (GCS > 13) when discharged from ICU. Mean left ventricular ejection fraction remained stable at 6 months. CONCLUSIONS: A significant proportion of patients admitted to the intensive care unit with a diagnosis of cardiac arrest secondary to acute coronary syndrome survive to hospital discharge with meaningful recovery in neurological and cardiac function.

Targeted temperature management in cardiovascular disease complicated by cardiac arrest.

PURPOSE: The majority of cardiac arrests occur due to cardiovascular etiology. Targeted temperature management (TTM) (32-34 °C) is a part of the standard post arrest care. We hypothesized that lower body temperature may lead to reduced cardiac metabolic demand and potentially have a beneficial effect on myocardial function. METHODS: We performed a retrospective study on patients admitted to the intensive care unit following cardiac arrest secondary to cardiovascular etiology over a 9 year period. We assessed the impact of TTM on neurological and cardiac outcomes. RESULTS: There were 57 patients in the cohort; 21 patients in the TTM group and 36 in the non-TTM group. Demographic characteristics were similar in both groups-the majority of patients (86 vs 80 %, respectively) were males in their 60s. Neurological outcomes were similar; 24 % of patients died during the ICU admission in the TTM group vs 18 % in the non-TTM group. Mean GCS on admission to the ICU was 4 vs 7, respectively, and 11 at discharge in both groups. Majority of patients recovered good neurological function (GCS ≥ 13)-57 % in the TTM group vs 64 % in the non-TTM group. The change in left ventricular function over a 6 month follow up period was significantly better in patients who received targeted temperature management-mean change of +4.4 vs -3.3 %, respectively. This proved to be statistically significant (p = 0.02). CONCLUSIONS: The study demonstrates a possible beneficial effect of TTM on long-term cardiac function, when instituted following cardiac arrest.

Observation of the 1S-2S transition in trapped antihydrogen.

The spectrum of the hydrogen atom has played a central part in fundamental physics over the past 200 years. Historical examples of its importance include the wavelength measurements of absorption lines in the solar spectrum by Fraunhofer, the identification of transition lines by Balmer, Lyman and others, the empirical description of allowed wavelengths by Rydberg, the quantum model of Bohr, the capability of quantum electrodynamics to precisely predict transition frequencies, and modern measurements of the 1S-2S transition by Hänsch to a precision of a few parts in 1015. Recent technological advances have allowed us to focus on antihydrogen-the antimatter equivalent of hydrogen. The Standard Model predicts that there should have been equal amounts of matter and antimatter in the primordial Universe after the Big Bang, but today's Universe is observed to consist almost entirely of ordinary matter. This motivates the study of antimatter, to see if there is a small asymmetry in the laws of physics that govern the two types of matter. In particular, the CPT (charge conjugation, parity reversal and time reversal) theorem, a cornerstone of the Standard Model, requires that hydrogen and antihydrogen have the same spectrum. Here we report the observation of the 1S-2S transition in magnetically trapped atoms of antihydrogen. We determine that the frequency of the transition, which is driven by two photons from a laser at 243 nanometres, is consistent with that expected for hydrogen in the same environment. This laser excitation of a quantum state of an atom of antimatter represents the most precise measurement performed on an anti-atom. Our result is consistent with CPT invariance at a relative precision of about 2 × 10-10.