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We propose a new theoretical model for metal pad roll instability in idealized cylindrical reduction cells. In addition to the usual destabilizing effects, we model viscous and Joule dissipation and some capillary effects. The resulting explicit formulas are used as theoretical benchmarks for two multiphase magnetohydrodynamic solvers, OpenFOAM and SFEMaNS. Our explicit formula for the viscous damping rate of gravity waves in cylinders with two fluid layers compares excellently to experimental measurements. We use our model to locate the viscously controlled instability threshold in cylindrical shallow reduction cells but also in Mg–Sb liquid metal batteries with decoupled interfaces.
To quantify the frequency and outcomes of receiving an antibiotic prescription upon discharge from the hospital to long-term care facilities (LTCFs).
Retrospective cohort study.
A 576-bed, academic hospital in Portland, Oregon.
Adult inpatients (≥18 years of age) discharged to an LTCF between January 1, 2012, and June 30, 2016.
Our primary outcome was receiving a systemic antibiotic prescription upon discharge to an LTCF. We also quantified the association between receiving an antibiotic prescription and 30-day hospital readmission, 30-day emergency department (ED) visit, and Clostridium difficile infection (CDI) on a readmission or ED visit at the index facility within 60 days of discharge.
Among 6,701 discharges to an LTCF, 22.9% were prescribed antibiotics upon discharge. The most prevalent antibiotic classes prescribed were cephalosporins (20.4%), fluoroquinolones (19.1%), and penicillins (16.7%). The medical records of ~82% of patients included a diagnosis code for a bacterial infection on the index admission. Among patients prescribed an antibiotic upon discharge, the incidence of 30-day hospital readmission to the index facility was 15.9%, the incidence of 30-day ED visit at the index facility was 11.0%, and the incidence of CDI on a readmission or ED visit within 60 days of discharge was 1.6%. Receiving an antibiotic prescription upon discharge was significantly associated with 30-day ED visits (adjusted odds ratio [aOR], 1.2; 95% confidence interval [CI], 1.02–1.5) and with CDI within 60 days (aOR, 1.7; 95% CI, 1.02–2.8) but not with 30-day readmissions (aOR, 1.01; 95% CI, 0.9–1.2).
Antibiotics were frequently prescribed upon discharge to LTCFs, which may be associated with increased risk of poor outcomes post discharge.
Postoperative cognitive impairment is among the most common medical complications associated with surgical interventions – particularly in elderly patients. In our aging society, it is an urgent medical need to determine preoperative individual risk prediction to allow more accurate cost–benefit decisions prior to elective surgeries. So far, risk prediction is mainly based on clinical parameters. However, these parameters only give a rough estimate of the individual risk. At present, there are no molecular or neuroimaging biomarkers available to improve risk prediction and little is known about the etiology and pathophysiology of this clinical condition. In this short review, we summarize the current state of knowledge and briefly present the recently started BioCog project (Biomarker Development for Postoperative Cognitive Impairment in the Elderly), which is funded by the European Union. It is the goal of this research and development (R&D) project, which involves academic and industry partners throughout Europe, to deliver a multivariate algorithm based on clinical assessments as well as molecular and neuroimaging biomarkers to overcome the currently unsatisfying situation.
Background: Hyponatremia has been found to be associated with increased complications in a variety of surgical populations. No study looked specifically at patients undergoing spine surgery. We also specifically address whether it has an effect on the typical low-risk patient admitted for degenerative spine disease, a population that forms the major bulk of clinical practice. Methods: Data was obtained from the American college of surgeons National Surgical Quality Improvement Program (ACS-NSQIP). All patients who underwent elective spinal surgery for degenerative disease from 2011 to 2013 were included. The two arms (normonatremic and hyponatremic) were then compared. Results: A total of 58049 patients were included, 3037 were hyponatremic. Hyponatremic patients were older and had more comorbidities. They also developed more minor and major complications. When all comorbidities were controlled for, hyponatremia was only associated with increased minor but not major complications. These patients were more likely to require a blood transfusion (OR=1.23, CI 1.10-1.43) and a prolonged hospital stay (OR=1.52, CI 1.33-1.75). Conclusions: This study finds an association between hyponatremia and postoperative adverse events in a low risk population that forms the major bulk of clinical practice. This addresses a potential target for quality improvement strategies with significant cost saving implications.
Of the many geophysical means that can be used to probe a planet's interior, seismology remains the most direct. Given that the seismic data gathered on the Moon over 40 years ago revolutionized our understanding of the Moon and are still being used today to produce new insight into the state of the lunar interior, it is no wonder that many future missions, both real and conceptual, plan to take seismometers to other planets.
To best facilitate the return of high-quality data from these instruments, as well as to further our understanding of the dynamic processes that modify a planet's interior, various modeling approaches are used to quantify parameters such as the amount and distribution of seismicity, tidal deformation, and seismic structure on and of the terrestrial planets. In addition, recent advances in wavefield modeling have permitted a renewed look at seismic energy transmission and the effects of attenuation and scattering, as well as the presence and effect of a core, on recorded seismograms. In this chapter, we will review these approaches.
Site selection for future planetary seismology missions
The ability of a seismic network to accurately locate an event improves as the number of seismometers increases. On Earth we take for granted that any given event will be relatively well located, due to the comparative ease of installation of seismometers. For planetary applications, we cannot count on a large distribution of stations. Various factors including cost, difficulty of installation, instrumentation longevity, and data transmission severely limit the number of instruments that have been or will be deployed on other planetary bodies. In this section, we will review various methods that can be employed to help determine the best landing sites for future planetary seismology missions, in order to maximize their scientific return. We focus here on the Moon and Mars, although many of these methods are adaptable to other planetary bodies.
Tuberculosis (TB) due to infection with Mycobacterium bovis is transmitted between cattle and badgers (Meles meles) in the UK and Ireland but it is unclear where or when transmission occurs. We investigated direct and indirect interactions between badgers and cattle using automated proximity loggers on animals and at badger latrines located on pasture, in an area of south-west England with a high-density badger population. Direct contacts (interactions within 1·4 m) between badgers and cattle at pasture were very rare (four out of >500 000 recorded animal-to-animal contacts) despite ample opportunity for interactions to occur. Indirect interactions (visits to badger latrines by badgers and cattle) were two orders of magnitude more frequent than direct contacts: 400 visits by badgers and 1700 visits by cattle were recorded. This suggests that indirect contacts might be more important than direct contacts in terms of disease transmission at pasture. The TB infection status of individual badgers (ascribed with 93% accuracy using three diagnostic tests) did not affect the frequency or duration of their visits to latrines located on pasture grazed by cattle. Nevertheless, there was wide variation in contact behaviour between individuals, which highlights the importance of understanding heterogeneity in contact patterns when developing strategies to control disease spread in wildlife and livestock.
Vaterite is one of the thermodynamically less stable polymorphs of calcium carbonate. Under ambient conditions it transforms into calcite, the most stable form of calcium carbonate. Organisms are able to stabilize minerals such as vaterite by means of organic molecules. The exact mechanisms how biomineralization proteins interact with metastable mineral phases are, however, less well understood. Many in vitro studies were performed using calcite as a model system. A deeper understanding of the interaction of organic molecules with metastable mineral phases would make them useful as a tool to control mineralization processes in vitro. In this study, we report on the co-precipitation of a natively soluble histidine-tagged GFP (green fluorecent protein) with a metastable vaterite phase and the subsequent insolubility of the fluorescent organic matrix in a 30μl calcium carbonate precipitation assay. The intrinsic fluorescence of GFP is conserved during the interaction with the mineral phase, indicating proper folding even in the insoluble state. This experiment can be extended to obtain deeper insights into some mechanistic models of biomineralization proteins by tracking native and modified GFP proteins microscopically during various stages of mineral precipitation and dissolution.
Accurate data on West Nile virus (WNV) cases help guide public health education and control activities, and impact regional WNV blood product screening procedures. During an outbreak of WNV disease in Arizona, records from patients with meningitis or encephalitis were reviewed to determine the proportion tested for WNV. Of 60 patients identified with meningitis or encephalitis, 24 (40%) were tested for WNV. Only 12 (28%) of 43 patients aged <50 years were tested for WNV compared to 12 (71%) of 17 patients aged ⩾50 years (P<0·01). Patients with clinical signs of weakness or paralysis, elevated CSF protein, admitted to an inpatient facility, or discharged to a rehabilitation facility were also more likely to have WNV testing performed. The lack of testing in younger age groups and in those with less severe disease probably resulted in substantial underestimates of WNV neuroinvasive disease burden.
Methods to induce non-thermal atmospheric pressure plasma filaments are presented with related properties for micro, streamer and prevented spark discharges, respectively, induced in planar Dielectric Barrier Discharges with one electrode covered by dielectric material (mono-DBD) or point-to-plane Corona. Two mechanisms of nano-particles formation are depicted from aerosol size distributions and TEM analysis. 0.1–10 mJ prevented spark discharges produce 10–100 nm droplets ejected from melted craters as well as nucleated primary particles and subsequent 10–100 nm agglomerates, by nucleation and coagulation in expanding vapor jets. With smaller energy per filament, 0.1–10 μJ micro-discharges and 0.1–100 μJ streamers, the initial local vapor fluxes emitted from spots of interaction between plasma filaments and electrodes are reduced. Subsequent smaller primary particle density limits the local coagulation in the vapor plume since 2–10 nm non-agglomerated crystalline metal nano-particles are produced in mono-DBD with Au, Ag and Cu electrode. Besides, the evolution of the aerosol size from primary nano-particles to agglomerates with transit time suggests slow coagulation of these primary metal particles in mono-DBD. Aerosol properties depend on the energy per filament and on the electrode. The final size is controlled by plasma parameters and transit time in and after the plasma. The aim is to underline emerging applications of atmospheric pressure plasmas for the production of tailored particles with tunable size, composition and structure with non-thermal plasma filaments to control the resulting properties of nano-powders and materials. Production rates and related energetic yields are compared.
Describe the clinical and molecular epidemiology of incident Clostridium difficile infection (CDI) cases in Chicago area acute healthcare facilities (HCFs).
Design and Setting.
Laboratory, clinical, and epidemiologic information was collected for patients with incident CDI who were admitted to acute HCFs in February 2009. Stool cultures and restriction endonuclease analysis typing of the recovered C. difficile isolates was performed.
Two hundred sixty-three patients from 25 acute HCFs.
Acute HCF rates ranged from 2 to 7 patients with CDI per 10,000 patient-days. The crude mortality rate was 8%, with 20 deaths occurring in patients with CDI. Forty-two (16%) patients had complications from CDI, including 4 patients who required partial, subtotal, or total colectomy, 3 of whom died. C. difficile was isolated and typed from 129 of 178 available stool specimens. The BI strain was identified in 79 (61%) isolates. Of patients discharged to long-term care who had their isolate typed, 36 (67%) had BI-associated CDI.
Severe disease was common and crude mortality was substantial among patients with CDI in Chicago area acute HCFs in February 2009. The outbreak-associated BI strain was the predominant endemic strain identified, accounting for nearly two-thirds of cases. Focal HCF outbreaks were not reported, despite the presence of the BI strain. Transfer of patients between acute and long-term HCFs may have contributed to the high incidence of BI cases in this investigation.
To present the auditory implant manipulator, a navigation-controlled mechanical and electronic system which enables minimally invasive (‘keyhole’) transmastoid access to the tympanic cavity.
Materials and methods:
The auditory implant manipulator is a miniaturised robotic system with five axes of movement and an integrated drill. It can be mounted on the operating table. We evaluated the surgical work field provided by the system, and the work sequence involved, using an anatomical whole head specimen.
The work field provided by the auditory implant manipulator is considerably greater than required for conventional mastoidectomy. The work sequence for a keyhole procedure included pre-operative planning, arrangement of equipment, the procedure itself and post-operative analysis.
Although system improvements are necessary, our preliminary results indicate that the auditory implant manipulator has the potential to perform keyhole insertion of implantable hearing devices.
The conditions in the strong law of large numbers given by Li et al. [‘A strong law for B-valued arrays’, Proc. Amer. Math. Soc.123 (1995), 3205–3212] for B-valued arrays are relaxed. Further, the compact logarithm rate law and the bounded logarithm rate law are discussed for the moving average process based on an array of random elements.
To determine risk factors for cholera in an epidemic-disease area in South America, a case–control investigation was performed in Guayaquil, Ecuador, in July 1991. Residents > 5 years old who were hospitalized for treatment of acute, watery diarrhoea and two matched controls for each were interviewed regarding sources of water and food, and eating, drinking, and hygienic habits. Interviewers inspected homes of case-patients and controls to document water treatment, food-handling, and hygienic practices. Faecal specimens and shellfish were cultured for Vibrio cholerae O 1. Isolates were tested for susceptibility to a variety of antimicrobial agents. Drinking unboiled water (odds ratio [OR] = 4.0, confidence interval [CI] = 1.8–7.5), drinking a beverage from a street vendor (OR = 2.8, CI = 1.3–5.9), eating raw seafood (OR = 3.4, CI = 1.4–11.5), and eating cooked crab (OR = 5.1, CI = 1.4–19.2) were associated with illness. Always boiling drinking water at home (OR = 0.5, CI = 0.2–0.9) was protective against illness. The presence of soap in either the kitchen (OR = 0.3, CI = 0.2–0.8) or bathroom (OR = 0.4, CI = 0.2–0.9) at home was also protective. V. cholerae O 1 was recovered from a pooled sample of a bivalve mollusc and from 68% of stool samples from case-patients. Thirty-six percent of the isolates from stool specimens were resistant to multiple antimicrobial agents. Specific prevention measures may prevent transmission through these vehicles in the future. The appearance of antimicrobial resistance suggests the need for changes in current methods of prevention and treatment.
Electron paramagnetic resonance (EPR) and photo EPR measurements were performed on undoped semi-insulating (SI) 6H SiC material grown by the physical vapor transport (PVT) method. EPR lines from a carbon-related surface defect, two photosensitive high temperature stable intrinsic defects with S=1/2 and shallow nitrogen and boron were observed. The EPR spectrum of the intrinsic defect labeled XX was observed in the dark and consists of three single lines XX1, XX2, XX3 due to three inequivalent sites in the 6H SiC. The second defect labeled PP appeared in EPR spectrum during photo-excitation of the SI 6H SiC and consisted of a single EPR line. The photo EPR data placed the energy level of the defects in the region EV + 1.24 ÷ 1.29 eV. The EPR parameters and symmetry behavior of XX agree well with those of the carbon vacancy-related Ky center observed in p-type electron irradiated 6H SiC and we tentatively identify the XX defect with VC+. The electronic processes occurring in undoped SI 6H SiC under photo-excitation are also described.
Kallenberg has introduced the concept of conditional spreadability for random sequences and has developed characterizations of this property in terms of one dimensional martingales and optional times, and as well has proven a predictable sampling theorem. This paper investigates the relationship between planar martingale structures and the natural analogues of conditional spreadability when extended to arrays of random elements. Analogues of the predictable sampling theorem are also established for spreadable arrays.