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Antibiotics are widely used by all specialties in the hospital setting. We evaluated previously defined high-risk antibiotic use in relation to Clostridioides difficile infections (CDIs).
We analyzed 2016–2017 data from 171 hospitals. High-risk antibiotics included second-, third-, and fourth-generation cephalosporins, fluoroquinolones, carbapenems, and lincosamides. A CDI case was a positive stool C. difficile toxin or molecular assay result from a patient without a positive result in the previous 8 weeks. Hospital-associated (HA) CDI cases included specimens collected >3 calendar days after admission or ≤3 calendar days from a patient with a prior same-hospital discharge within 28 days. We used the multivariable Poisson regression model to estimate the relative risk (RR) of high-risk antibiotic use on HA CDI, controlling for confounders.
The median days of therapy for high-risk antibiotic use was 241.2 (interquartile range [IQR], 192.6–295.2) per 1,000 days present; the overall HA CDI rate was 33 (IQR, 24–43) per 10,000 admissions. The overall correlation of high-risk antibiotic use and HA CDI was 0.22 (P = .003), and higher correlation was observed in teaching hospitals (0.38; P = .002). For every 100-day (per 1,000 days present) increase in high-risk antibiotic therapy, there was a 12% increase in HA CDI (RR, 1.12; 95% CI, 1.04–1.21; P = .002) after adjusting for confounders.
High-risk antibiotic use is an independent predictor of HA CDI. This assessment of poststewardship implementation in the United States highlights the importance of tracking trends of antimicrobial use over time as it relates to CDI.
This article extends the research focusing on the early origins of psychopathology into the prenatal period, by exploring the association between maternal prenatal depression and offspring (fetal and infant) neurobehavior. The sample is recruited from a rural population in South India where women in the third trimester of pregnancy were assessed for depression and the heart rate responses of their fetuses to extrinsically applied vibroacoustic stimuli were studied. At 2 months postbirth, infant temperament and cortisol responsivity to immunization were assessed. The association between maternal prenatal depression and fetal responsivity to vibroacoustic stimulation, and infant responsivity to immunization, was U shaped with higher levels of responsivity noted in the offspring of mothers with very high and very low depression scores, and lower levels noted in the offspring of mothers with moderate depression scores. Maternal prenatal depression was not associated with infant temperament. The findings highlight the importance of environmental influences in the developmental origins of neurobehavior, suggesting that such differences, not evident at baseline, may emerge upon exposure to stressors. The study also emphasizes the need for further investigation in low- and middle-income contexts by providing preliminary evidence of the differing patterns of association observed between high- and low-income populations.
The true nature of the association between pulsars and supernova remnants has remained an intriguing and poorly understood problem even after all these years of research on them. We attempt in this review to marshal all the evidence one has on this question, and to see what conclusions we can draw.
Ferromagnetic/Ferroelectric/Ferromagnetic (Ni/PZT/Ni) tri-layer artificial multiferroelectric structures in spin capacitor configuration were fabricated by sputtering ferromagnetic electrodes on PZT. Magnetocapacitance, magnetoimpedance, and phase angle measurements were carried out by a wide range of frequencies and magnetic fields at room temperature. We also compared the magnetodielectric measurements with Ni/PZT/Ag and Ag/PZT/Ag tri-layers structures. Ni/PZT/Ni spin capacitor shows a significantly different behavior compared to conventional PZT capacitor with Ag electrode and mixed electrode capacitor with one ferromagnetic and one conventional electrode.
We have made HI 21cm-line absorption measurements using the GMRT towards 15 directions in the Galaxy which are known to have high random velocity clouds as seen in the optical absorption lines of CaII and NaI. For the first time, in 6 out of these 15 directions we detect HI absorption features corresponding to the high random velocity optical absorption lines. The mean optical depth of these detections is ∼ 0.08.
The IRAS Vela shell was first seen as a ring of infrared emission in the IRAS maps of the Gum-Vela region coincident with the Gum Nebula. We have studied the kinematics of the molecular material (12CO) associated with the IRAS point sources and Southern Dark Clouds seen in this region and established the presence of a giant expanding shell of molecular gas. The estimated mass, size and expansion velocity of the shell lead us to conclude that it is the remnant of a GMC, in the process of disintegration through the influence of a central OB association. We conjecture that the IRAS Vela shell is a nearby example of a “super shell” in its early stages of evolution and as such is an ideal opportunity to study these objects now widely seen both in our Galaxy and in new observations of the Magellanic Clouds.
We use the recently introduced concept of a “window” of magnetic field strengths in which pulsars can be active to explain the variation in morphology of supernova remnants. Neutron stars created with field strengths of a value permitting pulsar activity result in particle production and Crab-like centrally concentrated remnants. Other field values lead to strong magnetic dipole radiation and consequent shell formation, e.g., Cas A.
We analyze the dust emission features seen in Spitzer Space Telescope Infrared Spectrograph (IRS) spectra of red supergiant (RSG) and oxygen-rich asymptotic giant branch (AGB) stars in the Large Magellanic Cloud and Small Magellanic Cloud galaxies and in various Milky Way globular clusters. The spectra come from the Spitzer Legacy program SAGE-Spectroscopy (PI: F. Kemper), the Spitzer program SMC-Spec (PI: G. Sloan), and other archival Spitzer-IRS programs. The broad 10 and 20 micron emission features attributed to amorphous dust of silicate composition seen in the spectra show evidence for systematic differences in the centroid of both emission features between O-rich AGB and RSG populations. Radiative transfer modeling using the GRAMS grid of models of AGB and RSG stars suggests that the centroid differences are due to differences in dust properties. We investigate differences in dust composition, size, shape, etc that might be responsible for these spectral differences. We explore how these differences may arise from the different circumstellar environments around RSG and O-rich AGB stars and assess effects of varying metallicity (LMC versus SMC versus Milky Way globular cluster) and other properties (mass-loss rate, luminosity, etc.) on the dust originating from these stars. BAS acknowledges funding from NASA ADAP grant NNX13AD54G.
Maternal stress during pregnancy has pervasive effects on stress responsivity in children. This study is the first to test the hypothesis that maternal prenatal depression, as observed in South India, may be associated with how foetuses respond to a potentially stressful stimulus. We employed measures of foetal heart rate at baseline, during exposure to a vibroacoustic stimulus, and post-stimulation, to study patterns of response and recovery in 133 third trimester foetuses of depressed and non-depressed mothers. We show that the association between maternal depression and foetal stress responsivity is U-shaped with foetuses of mothers with high and low depression scores demonstrating elevated responses, and poorer recovery, than foetuses of mothers with moderate levels. The right amount of intra-uterine stimulation is important in conditioning foetuses towards optimal regulation of their stress response. Our results imply that, in certain environmental contexts, exposure to moderate amounts of intra-uterine stress may facilitate this process.
Active surveillance to identify asymptomatic carriers of carbapenem-resistant Enterobacteriaceae (CRE) is a recommended strategy for CRE control in healthcare facilities. Active surveillance using stool specimens tested for Clostridium difficile is a relatively low-cost strategy to detect CRE carriers. Further evaluation of this and other risk factor-based active surveillance strategies is warranted.
Hybrid silicon laser is a promising solution to enable high-performance light source on large-scale, silicon-based photonic integrated circuits (PICs). As a compact laser cavity design, hybrid microring lasers are attractive for their intrinsic advantages of small footprint, low power consumption and flexibility in wavelength division multiplexing (WDM), etc. Here we review recent progress in unidirectional microring lasers and device thermal management. Unidirectional emission is achieved by integrating a passive reflector that feeds laser emission back into laser cavity to introduce extra unidirectional gain. Up to 4X of device heating reduction is simulated by adding a metal thermal shunt to the laser to “short” heat to the silicon substrate through buried oxide layer (BOX) in the silicon-on-insulator (SOI) substrate. Obvious device heating reduction is also observed in experiment.
A study is made of the rotation field in wedge indentation of metals using copper as the model material system. Wedges with apical angles of 60° and 120° are used to indent annealed copper, and the deformation is mapped using image correlation. The indentation of annealed and strain-hardened copper is simulated using finite element analysis. The rotation field, derived from the deformation measurements, provides a clear way of distinguishing between cutting and compressive modes of deformation. Largely unidirectional rotation on one side of the symmetry line with small spatial rotation gradients is characteristic of compression. Bidirectional rotation with neighboring regions of opposing rotations and locally high rotation gradients characterizes cutting. In addition, the rotation demarcates such characteristic regions as the pile-up zone in indentation of a strain-hardened metal. The residual rotation field obtained after unloading is essentially the same as that at full load, indicating that it is a scalar proxy for plastic deformation as a whole.
The mechanical properties and dislocation microstructure of single crystals with a range of compositions within the Fex-Ni60–x-Al40 pseudobinary system have been investigated, with the purpose of bridging the behavior from FeAl to NiAl. Experiments are focused on the compression testing of <001> oriented single crystals with compositions where x = 10, 20, 30, 40, and 50 (in atomic percent). Observations of a<111> dislocation morphologies at room temperature and both a<111> and non-a<111> dislocation activity at elevated temperatures are reported and discussed. Measurements of the yield strength, elastic modulus and strain hardening rates are reported, and the variation of strength with composition is correlated with dislocation dissociation and overall dislocation morphology.
The Johns Hopkins University Applied Physics Laboratory is developing packaging for a sensor platform to be embedded in the harsh environment of concrete structures. The sensors will monitor the corrosive environment of the structure over periods of several decades to aid in scheduling maintenance and repair.
The United States has recognized the risks associated with its aging infrastructure and is actively replacing deteriorated/high risk structures as well as simultaneously developing the tools and techniques to monitor new infrastructure as it ages. JHU/APL has reviewed the sensing requirements for infrastructure monitoring, especially bridge decks, and developed a concept based on distributed, embedded sensors. The Wireless, Embedded Sensor Platform (WESP) will implement the concept of a low-cost, customizable sensor platform suitable for long-term field measurements. The WESP is designed to be powered and queried remotely as often as required and can be used to measure the evolution of the corrosive environment over time.
The objective of this research and development is to design, implement, and demonstrate packaging techniques for embedded sensor suites commensurate with a 50-year lifetime when embedded in concrete having a pH greater than 13, and exposed to harsh environments of salt, and mechanical and thermal stress. To meet this objective, the WESP construction will use a commercial ceramic IC package and unique manufacturing and assembly techniques.
The prototype is expected to provide sensor identification, temperature, pressure, and conductivity data within a package volume less than 2.5 cm3 (0.15 in3). Reliability test results will be reviewed and specialized tests will be performed to evaluate the performance of the packaging design. These include such tests as freeze/thaw cycling, thermal shock, thermal cycling, Highly Accelerated Stress Test (HAST), 85% relative humidity/85°C, and accelerated life testing. Future developments are expected to reduce size and implement additional sensor types to fully characterize the concrete environment.
A procedure to be used in ion implantation calculations has been developed to determine the stopping power of an ion at low energy as a function of its effective charge. The ion effective charge accounts for screening of the ion and has been found to have considerable effect on the stopping power through its dependence on the target electron density. Steps in the procedure include: the calculation of the Fermi momentum of the target, calculation of the relative velocity between the projectile and target electron cloud, determination of the screening distance for the ion, and calculation of the proton stopping power Sp according to the density-functional formalism. The ion stopping power is then is the ion effective charge. The procedure can be applied to semiconductors and metals. Comparisons are reported with the predictions of the Firsov and Lindhard methods which do not include any effective charge or shell structure considerations. The computer program MARLOWE has been modified to include this method for calculating the stopping power. Results in the form of implanted boron profiles in silicon will be presented.
We present an atomistic model to study void formation in aluminum interconnects in integrated circuit (1C) chips. Aluminum single and bicrystals were studied with various concentrations of vacancies and strain levels. It was found that either vacancies or tensile strains could lead to void formation. It will be shown that the void formation can be prevented by maintaining compressive strains in the computational cells.
Ablation and etching of the surface of polymethyl methacrylate (=PMMA) by pulses of 248 nm laser radiation ∼20 ns full width at half maximum (FWHM) have been probed by pulses of visible laser radiation (596 nm; < 1 ns FWHM). The results were recorded photographically in real time with a set time delay between the 248 nm ablation pulse and the 596 nm probe pulse. Modification of the surface structure of the polymer at a fluence ∼ 3 J/cm2 is first visible at 12 ns and appears to be complete in ∼ 60 ns. The first manifestation of the ablation does not occur until the UV pulse is over and consists of a nearly transparent shock-wave that has an initial velocity of 6 ∼ 104 cm/sec. Solid material from the ablated zone begins to leave the surface at ∼150 - 200 ns and reaches a maximum in intensity at 6 µs, continuing for ∼ 20 µs. The average velocity of the solid material, which is probably a low molecular weight polymer of PMMA, is 1.5 ∼ 104 cm/sec. The conclusion to be drawn from the present work is that the signal measured by photoacoustic detectors does not coincide with the bulk of the material leaving the surface.